Sample records for generate heat flow

  1. Heat transfer and pressure drop in tape generated swirl flow

    E-Print Network [OSTI]

    Lopina, Robert F.

    1967-01-01T23:59:59.000Z

    The heat transfer and pressure drop characteristics of water in tape generated swirl flow were investigated. The test sections were electrically heated small diameter nickel tubes with tight fitting full length Inconel ...

  2. Cooling Flows or Heating Flows?

    E-Print Network [OSTI]

    James Binney

    2003-10-08T23:59:59.000Z

    It is now clear that AGN heat cooling flows, largely by driving winds. The winds may contain a relativistic component that generates powerful synchrotron radiation, but it is not clear that all winds do so. The spatial and temporal stability of the AGN/cooling flow interaction are discussed. Collimation of the winds probably provides spatial stability. Temporal stability may be possible only for black holes with masses above a critical value. Both the failure of cooling flows to have adiabatic cores and the existence of X-ray cavities confirm the importance of collimated outflows. I quantify the scale of the convective flow that the AGN Hydra would need to drive if it balanced radiative inward flow by outward flow parallel to the jets. At least in Virgo any such flow must be confined to r<~20 kpc. Hydrodynamical simulations suggest that AGN outbursts cannot last longer than ~25 Myr. Data for four clusters with well studied X-ray cavities suggests that heating associated with cavity formation approximately balances radiative cooling. The role of cosmic infall and the mechanism of filament formation are briefly touched on.

  3. New tube bundle heat transfer correlations and flow regime maps for a Once Through Steam Generator

    E-Print Network [OSTI]

    Blanchat, Thomas Kevin

    1988-01-01T23:59:59.000Z

    completed which allow the user to input the pitch and tube o. d. for the system. Predicted RELAP5/MOD2 heat transfer coefficients from correlations have been reviewed for single phase liquid convection, subcooled, and saturated nu- cleate boiling... of the OTSG model to determine the "model efFects" prior to changing any thermal ? hydraulic correlations. These studies inves- tigated the effects of hydraulic diameter, tube bundle surface heat transfer area, snd inlet feedwater subcooling, in addition...

  4. Convective heat flow probe

    DOE Patents [OSTI]

    Dunn, J.C.; Hardee, H.C.; Striker, R.P.

    1984-01-09T23:59:59.000Z

    A convective heat flow probe device is provided which measures heat flow and fluid flow magnitude in the formation surrounding a borehole. The probe comprises an elongate housing adapted to be lowered down into the borehole; a plurality of heaters extending along the probe for heating the formation surrounding the borehole; a plurality of temperature sensors arranged around the periphery of the probe for measuring the temperature of the surrounding formation after heating thereof by the heater elements. The temperature sensors and heater elements are mounted in a plurality of separate heater pads which are supported by the housing and which are adapted to be radially expanded into firm engagement with the walls of the borehole. The heat supplied by the heater elements and the temperatures measured by the temperature sensors are monitored and used in providing the desired measurements. The outer peripheral surfaces of the heater pads are configured as segments of a cylinder and form a full cylinder when taken together. A plurality of temperature sensors are located on each pad so as to extend along the length and across the width thereof, with a heating element being located in each pad beneath the temperature sensors. An expansion mechanism driven by a clamping motor provides expansion and retraction of the heater pads and expandable packet-type seals are provided along the probe above and below the heater pads.

  5. Radial flow heat exchanger

    DOE Patents [OSTI]

    Valenzuela, Javier (Hanover, NH)

    2001-01-01T23:59:59.000Z

    A radial flow heat exchanger (20) having a plurality of first passages (24) for transporting a first fluid (25) and a plurality of second passages (26) for transporting a second fluid (27). The first and second passages are arranged in stacked, alternating relationship, are separated from one another by relatively thin plates (30) and (32), and surround a central axis (22). The thickness of the first and second passages are selected so that the first and second fluids, respectively, are transported with laminar flow through the passages. To enhance thermal energy transfer between first and second passages, the latter are arranged so each first passage is in thermal communication with an associated second passage along substantially its entire length, and vice versa with respect to the second passages. The heat exchangers may be stacked to achieve a modular heat exchange assembly (300). Certain heat exchangers in the assembly may be designed slightly differently than other heat exchangers to address changes in fluid properties during transport through the heat exchanger, so as to enhance overall thermal effectiveness of the assembly.

  6. New tube bundle heat transfer correlations and flow regime maps for a Once Through Steam Generator

    E-Print Network [OSTI]

    Blanchat, Thomas Kevin

    1988-01-01T23:59:59.000Z

    Support Group for their many helpful discussions and comments throughout this project. I would like to thank Mr. Richard Wagner at EGgrG, Idaho, for his patient explanations of the mechanics of the RELAP5/MOD2 code which enabled me to perform the code... completed which allow the user to input the pitch and tube o. d. for the system. Predicted RELAP5/MOD2 heat transfer coefficients from correlations have been reviewed for single phase liquid convection, subcooled, and saturated nu- cleate boiling...

  7. Control system for fluid heated steam generator

    DOE Patents [OSTI]

    Boland, James F. (Bonneville County, ID); Koenig, John F. (Idaho Falls, ID)

    1985-01-01T23:59:59.000Z

    A control system for controlling the location of the nucleate-boiling region in a fluid heated steam generator comprises means for measuring the temperature gradient (change in temperature per unit length) of the heating fluid along the steam generator; means for determining a control variable in accordance with a predetermined function of temperature gradients and for generating a control signal in response thereto; and means for adjusting the feedwater flow rate in accordance with the control signal.

  8. Control system for fluid heated steam generator

    DOE Patents [OSTI]

    Boland, J.F.; Koenig, J.F.

    1984-05-29T23:59:59.000Z

    A control system for controlling the location of the nucleate-boiling region in a fluid heated steam generator comprises means for measuring the temperature gradient (change in temperature per unit length) of the heating fluid along the steam generator; means for determining a control variable in accordance with a predetermined function of temperature gradients and for generating a control signal in response thereto; and means for adjusting the feedwater flow rate in accordance with the control signal.

  9. Waste Heat Recovery Opportunities for Thermoelectric Generators...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Waste Heat Recovery Opportunities for Thermoelectric Generators Waste Heat Recovery Opportunities for Thermoelectric Generators Thermoelectrics have unique advantages for...

  10. Skutterudite Thermoelectric Generator For Automotive Waste Heat...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Skutterudite Thermoelectric Generator For Automotive Waste Heat Recovery Skutterudite Thermoelectric Generator For Automotive Waste Heat Recovery Skutterudite TE modules were...

  11. Colorado: Isothermal Battery Calorimeter Quantifies Heat Flow...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Isothermal Battery Calorimeter Quantifies Heat Flow, Helps Make Safer, Longer-lasting Batteries Colorado: Isothermal Battery Calorimeter Quantifies Heat Flow, Helps Make Safer,...

  12. Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal...

    Open Energy Info (EERE)

    heat flow values as high as several watts per meter squared can be found. Systematic interpretation of heat flow patterns sheds light on heat transfer mechanisms at depth on...

  13. Rťnyi entropy flows from quantum heat engines

    E-Print Network [OSTI]

    Mohammad H. Ansari; Yuli V. Nazarov

    2015-03-20T23:59:59.000Z

    We evaluate Renyi entropy flows from generic quantum heat engines (QHE) to a weakly-coupled probe environment kept in thermal equilibrium. We show that the flows are determined not only by heat flow but also by a quantum coherent flow that can be separately measured in experiment apart from the heat flow measurement. The same pertains to Shanon entropy flow. This appeals for a revision of the concept of entropy flows in quantum nonequlibrium thermodynamics.

  14. Colorado Heat Flow Data from IHFC

    SciTech Connect (OSTI)

    Zehner, Richard E.

    2012-02-01T23:59:59.000Z

    Citation Information: Originator: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Originator: The International Heat Flow Commission (IHFC) Publication Date: 2012 Title: Colorado IHFC Data Edition: First Publication Information: Publication Place: Earth Science & Observation Center, Cooperative Institute for Research in Environmental Science (CIRES), University of Colorado, Boulder Publisher: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Description: Abstract: This layer contains the heat flow sites and data of the State of Colorado compiled from the International Heat Flow Commission (IHFC) of the International Association of Seismology and Physics of the Earth's Interior (IASPEI) global heat flow database (www.heatflow.und.edu/index2.html). The data include different items: Item number, descriptive code, name of site, latitude and longitude, elevation, depth interval, number of temperature data, temperature gradient, number of conductivity measurement, average conductivity, number of heat generation measurements, average heat production, heat flow, number of individual sites, references, and date of publication. Spatial Domain: Extent: Top: 4522121.800672 m Left: 165356.134075 m Right: 621836.776246 m Bottom: 4097833.419676 m Contact Information: Contact Organization: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Contact Person: Khalid Hussein Address: CIRES, Ekeley Building Earth Science & Observation Center (ESOC) 216 UCB City: Boulder State: CO Postal Code: 80309-0216 Country: USA Contact Telephone: 303-492-6782 Spatial Reference Information: Coordinate System: Universal Transverse Mercator (UTM) WGSí1984 Zone 13N False Easting: 500000.00000000 False Northing: 0.00000000 Central Meridian: -105.00000000 Scale Factor: 0.99960000 Latitude Of Origin: 0.00000000 Linear Unit: Meter Datum: World Geodetic System 1984 (WGS í1984) Prime Meridian: Greenwich Angular Unit: Degree Digital Form: Format Name: Shape file

  15. Distributed Generation with Heat Recovery and Storage

    E-Print Network [OSTI]

    Siddiqui, Afzal S.; Marnay, Chris; Firestone, Ryan M.; Zhou, Nan

    2008-01-01T23:59:59.000Z

    selection of on-site power generation with combined heat andTotal Electricity Generation Figure 13. Small MercantileWeekday Total Electricity Generation (No Storage Adoption

  16. Thermoelectric Generator Development for Automotive Waste Heat...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    for Automotive Waste Heat Recovery Thermoelectric Generator Development for Automotive Waste Heat Recovery Presentation given at the 16th Directions in Engine-Efficiency and...

  17. Geothermal Heat Flow and Existing Geothermal Plants | Department...

    Energy Savers [EERE]

    Geothermal Heat Flow and Existing Geothermal Plants Geothermal Heat Flow and Existing Geothermal Plants Geothermal Heat Flow and Existing Plants With plants in development. Click...

  18. Control of flow through a vapor generator

    DOE Patents [OSTI]

    Radcliff, Thomas D.

    2005-11-08T23:59:59.000Z

    In a Rankine cycle system wherein a vapor generator receives heat from exhaust gases, provision is made to avoid overheating of the refrigerant during ORC system shut down while at the same time preventing condensation of those gases within the vapor generator when its temperature drops below a threshold temperature by diverting the flow of hot gases to ambient and to thereby draw ambient air through the vapor generator in the process. In one embodiment, a bistable ejector is adjustable between one position, in which the hot gases flow through the vapor generator, to another position wherein the gases are diverted away from the vapor generator. Another embodiment provides for a fixed valve ejector with a bias towards discharging to ambient, but with a fan on the downstream side of said vapor generator for overcoming this bias.

  19. Solar steam generation by heat localization

    E-Print Network [OSTI]

    Ghasemi, Hadi

    Currently, steam generation using solar energy is based on heating bulk liquid to high temperatures. This approach requires either costly high optical concentrations leading to heat loss by the hot bulk liquid and heated ...

  20. Heat Transfer Characteristics of a Generalized Divided Flow Heat Exchanger

    E-Print Network [OSTI]

    Singh, K. P.

    1979-01-01T23:59:59.000Z

    The concept of a "Divided-flow" heat exchanger is generalized by locating the shell inlet (or outlet) nozzle off-center such that the two shell sub-streams are unequal and traverse unequal flow paths. The governing equations for heat transfer...

  1. Heat engine generator control system

    DOE Patents [OSTI]

    Rajashekara, Kaushik (Carmel, IN); Gorti, Bhanuprasad Venkata (Towson, MD); McMullen, Steven Robert (Anderson, IN); Raibert, Robert Joseph (Fishers, IN)

    1998-01-01T23:59:59.000Z

    An electrical power generation system includes a heat engine having an output member operatively coupled to the rotor of a dynamoelectric machine. System output power is controlled by varying an electrical parameter of the dynamoelectric machine. A power request signal is related to an engine speed and the electrical parameter is varied in accordance with a speed control loop. Initially, the sense of change in the electrical parameter in response to a change in the power request signal is opposite that required to effectuate a steady state output power consistent with the power request signal. Thereafter, the electrical parameter is varied to converge the output member speed to the speed known to be associated with the desired electrical output power.

  2. Heat engine generator control system

    DOE Patents [OSTI]

    Rajashekara, K.; Gorti, B.V.; McMullen, S.R.; Raibert, R.J.

    1998-05-12T23:59:59.000Z

    An electrical power generation system includes a heat engine having an output member operatively coupled to the rotor of a dynamoelectric machine. System output power is controlled by varying an electrical parameter of the dynamoelectric machine. A power request signal is related to an engine speed and the electrical parameter is varied in accordance with a speed control loop. Initially, the sense of change in the electrical parameter in response to a change in the power request signal is opposite that required to effectuate a steady state output power consistent with the power request signal. Thereafter, the electrical parameter is varied to converge the output member speed to the speed known to be associated with the desired electrical output power. 8 figs.

  3. A Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow...

    Open Energy Info (EERE)

    The Uk Geothermal Catalogue Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: A Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow...

  4. Heat transfer and flow on the first-stage blade tip of a power generation gas turbine: Part 2 -- Simulation results

    SciTech Connect (OSTI)

    Ameri, A.A.; Bunker, R.S.

    2000-04-01T23:59:59.000Z

    A combined experimental and computational study has been performed to investigate the detailed distribution of convective heat transfer coefficients on the first-stage blade tip surface for a geometry typical of large power generation turbines (> 100 MW). This paper is concerned with the numerical prediction of the tip surface heat transfer. Good comparison with the experimental measured distribution was achieved through accurate modeling of the most important features of the blade passage and heating arrangement as well as the details of experimental rig likely to affect the tip heat transfer. A sharp edge and a radiused edge tip was considered. The results using the radiused edge tip agreed better with the experimental data. This improved agreement was attributed to the absence of edge separation on the tip of the radiused edge blade.

  5. Skutterudite Thermoelectric Generator For Automotive Waste Heat...

    Broader source: Energy.gov (indexed) [DOE]

    Skutterudite Thermoelectric Generator For Automotive Waste Heat Recovery Gregory P. Meisner General Motors Global Research & Development March 21, 2012 3rd Thermoelectric...

  6. MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER

    E-Print Network [OSTI]

    Lahey, Richard T.

    MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER "ENGINEERING APPLICATIONS OF FRACTAL AND CHAOS THEORY" RICHARD T. LAHEY, JR. Center for Multiphase Research Rensselaer Polytechnic Institute Troy and multiphase flow & heat transfer will be stressed. This paper will begin by reviewing some important concepts

  7. Waste Heat Recovery Power Generation with WOWGen

    E-Print Network [OSTI]

    Romero, M.

    applications of heat recovery power generation can be found in Industry (e.g. steel, glass, cement, lime, pulp and paper, refining and petrochemicals), Power Generation (CHP, biomass, biofuel, traditional fuels, gasifiers, diesel engines) and Natural Gas...

  8. A Thermoelectric Generator with an Intermediate Heat Exchanger...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    A Thermoelectric Generator with an Intermediate Heat Exchanger for Automotive Waste Heat Recovery System A Thermoelectric Generator with an Intermediate Heat Exchanger for...

  9. Heat Flow Database Expansion for NGDS Data Development, Collection...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Heat Flow Database Expansion for NGDS Data Development, Collection and Maintenance (SMU) Heat Flow Database Expansion for NGDS Data Development, Collection and Maintenance (SMU)...

  10. Heat transfer and flow on the first-stage blade tip of a power generation gas turbine: Part 1 -- Experimental results

    SciTech Connect (OSTI)

    Bunker, R.S.; Bailey, J.C.; Ameri, A.A.

    2000-04-01T23:59:59.000Z

    A combined experimental and computational study has been performed to investigate the detailed distribution of convective heat transfer coefficients on the first-stage blade tip surface for a geometry typical of large power generation turbines (> 100 MW). This paper is concerned with the design and execution of the experimental portion of the study, which represents the first reported investigation to obtain nearly full surface information on heat transfer coefficients within an environment that develops an appropriate pressure distribution about an airfoil blade tip and shroud model. A stationary blade cascade experiment has been run consisting of three airfoils, the center airfoil having a variable tip gap clearance. The airfoil models the aerodynamic tip section of a high-pressure turbine blade with inlet Mach number of 0.30, exit Mach number of 0.75, pressure ratio of 1.45, exit Reynolds number based on axial chord of 2.57 x 10{sup 6}, and total turning of about 110 degrees. A hue detection based liquid crystal method is used to obtain the detailed heat transfer coefficient distribution on the blade tip surface for flat, smooth tip surfaces with both sharp and rounded edges. The cascade inlet turbulence intensity level took on values of either 5 or 9%. The cascade also models the casing recess in the shroud surface ahead of the blade. Experimental results are shown for the pressure distribution measurements on the airfoil near the tip gap, on the blade tip surface, and on the opposite shroud surface. Tip surface heat transfer coefficient distributions are shown for sharp edge and rounded edge tip geometries at each of the inlet turbulence intensity levels.

  11. Constructal multi-scale package of vertical channels with natural convection and maximal heat transfer density. CONSTRUCTAL DESIGN: THE GENERATION OF MULTI-SCALE HEAT

    E-Print Network [OSTI]

    Kihm, IconKenneth David

    transfer density. CONSTRUCTAL DESIGN: THE GENERATION OF MULTI-SCALE HEAT AND FLUID FLOW STRUCTURES-scale structures in natural convection with the objective of maximizing the heat transfer density, or the heat transfer rate per unit of volumeß . The flow volume is filled with vertical equidistant heated blades

  12. Corner heating in rectangular solid oxide electrochemical cell generators

    DOE Patents [OSTI]

    Reichner, Philip (Plum Boro, PA)

    1989-01-01T23:59:59.000Z

    Disclosed is an improvement in a solid oxide electrochemical cell generator 1 having a rectangular design with four sides that meet at corners, and containing multiplicity of electrically connected fuel cells 11, where a fuel gas is passed over one side of said cells and an oxygen containing gas is passed into said cells, and said fuel is burned to form heat, electricity, and an exhaust gas. The improvement comprises passing the exhaust gases over the multiplicity of cells 11 in such a way that more of the heat in said exhaust gases flows at the corners of the generator, such as through channels 19.

  13. Modular Low Cost High Energy Exhaust Heat Thermoelectric Generator...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Low Cost High Energy Exhaust Heat Thermoelectric Generator with Closed-Loop Exhaust By-Pass System Modular Low Cost High Energy Exhaust Heat Thermoelectric Generator with...

  14. Automatic Control Flow Generation from Software Architectures

    E-Print Network [OSTI]

    Lau, Kung-Kiu

    -time automatically. To achieve this we take a different approach to system construction. We take control out.-K. Lau and V. Ukis generic connectors, and generate control flow of the system automatically at run in different systems with different control flows. Our automatic runtime control flow generation not only

  15. Heat Transfer Enhancement for Finned-Tube Heat Exchangers with Vortex Generators: Experimental and Numerical Results

    SciTech Connect (OSTI)

    O'Brien, James Edward; Sohal, Manohar Singh; Huff, George Albert

    2002-08-01T23:59:59.000Z

    A combined experimental and numerical investigation is under way to investigate heat transfer enhancement techniques that may be applicable to large-scale air-cooled condensers such as those used in geothermal power applications. The research is focused on whether air-side heat transfer can be improved through the use of finsurface vortex generators (winglets,) while maintaining low heat exchanger pressure drop. A transient heat transfer visualization and measurement technique has been employed in order to obtain detailed distributions of local heat transfer coefficients on model fin surfaces. Pressure drop measurements have also been acquired in a separate multiple-tube row apparatus. In addition, numerical modeling techniques have been developed to allow prediction of local and average heat transfer for these low-Reynolds-number flows with and without winglets. Representative experimental and numerical results presented in this paper reveal quantitative details of local fin-surface heat transfer in the vicinity of a circular tube with a single delta winglet pair downstream of the cylinder. The winglets were triangular (delta) with a 1:2 height/length aspect ratio and a height equal to 90% of the channel height. Overall mean fin-surface Nusselt-number results indicate a significant level of heat transfer enhancement (average enhancement ratio 35%) associated with the deployment of the winglets with oval tubes. Pressure drop measurements have also been obtained for a variety of tube and winglet configurations using a single-channel flow apparatus that includes four tube rows in a staggered array. Comparisons of heat transfer and pressure drop results for the elliptical tube versus a circular tube with and without winglets are provided. Heat transfer and pressure-drop results have been obtained for flow Reynolds numbers based on channel height and mean flow velocity ranging from 700 to 6500.

  16. Local entropy generation for saturated two-phase flow Remi Revellin a,*, Stephane Lips a

    E-Print Network [OSTI]

    Khandekar, Sameer

    the porous medium approach based on extended Darcy equation for fluid flow, and two-equation model for heat Keywords: Entropy generation Two-phase flow Saturated flow boiling Clapeyron equation a b s t r a c] has proposed equations for enhanced heat transfer surfaces to include the effect of fluid temperature

  17. Triaxial thermopile array geo-heat-flow sensor

    DOE Patents [OSTI]

    Carrigan, C.R.; Hardee, H.C.; Reynolds, G.D.; Steinfort, T.D.

    1990-01-01T23:59:59.000Z

    A triaxial thermopile array geothermal heat flow sensor is designed to measure heat flow in three dimensions in a reconstituted or unperturbed subsurface regime. Heat flow can be measured in conductive or permeable convective media. The sensor may be encased in protective pvc tubing and includes a plurality of thermistors and an array of heat flow transducers produce voltage proportional to heat flux along the subsurface regime and permit direct measurement of heat flow in the subsurface regime. The presence of the thermistor array permits a comparison to be made between the heat flow estimates obtained from the transducers and heat flow calculated using temperature differences and Fourier's Law. The device is extremely sensitive with an accuracy of less than 0.1 Heat Flow Units (HFU) and may be used for long term readings. 6 figs.

  18. Triaxial thermopile array geo-heat-flow sensor

    DOE Patents [OSTI]

    Carrigan, Charles R. (Tracy, CA); Hardee, Harry C. (Albuquerque, NM); Reynolds, Gerald D. (Tijeras, NM); Steinfort, Terry D. (Tijeras, NM)

    1992-01-01T23:59:59.000Z

    A triaxial thermopile array geothermal heat flow sensor is designed to measure heat flow in three dimensions in a reconstituted or unperturbed subsurface regime. Heat flow can be measured in conductive or permeable convective media. The sensor may be encased in protective pvc tubing and includes a plurality of thermistors and an array of heat flow transducers arranged in a vertical string. The transducers produce voltage proportional to heat flux along the subsurface regime and permit direct measurement of heat flow in the subsurface regime. The presence of the thermistor array permits a comparison to be made between the heat flow estimates obtained from the transducers and heat flow calculated using temperature differences and Fourier's Law. The device is extremely sensitive with an accuracy of less than 0.1 Heat Flow Units (HFU) and may be used for long term readings.

  19. Distributed Generation with Heat Recovery and Storage

    SciTech Connect (OSTI)

    Siddiqui, Afzal; Marnay, Chris; Firestone, Ryan M.; Zhou, Nan

    2005-07-29T23:59:59.000Z

    Electricity generated by distributed energy resources (DER) located close to end-use loads has the potential to meet consumer requirements more efficiently than the existing centralized grid. Installation of DER allows consumers to circumvent the costs associated with transmission congestion and other non-energy costs of electricity delivery and potentially to take advantage of market opportunities to purchase energy when attractive. On-site thermal power generation is typically less efficient than central station generation, but by avoiding non-fuel costs of grid power and utilizing combined heat and power (CHP) applications, i.e., recovering heat from small-scale on-site generation to displace fuel purchases, then DER can become attractive to a strictly cost-minimizing consumer. In previous efforts, the decisions facing typical commercial consumers have been addressed using a mixed-integer linear programme, the DER Customer Adoption Model(DER-CAM). Given the site s energy loads, utility tariff structure, and information (both technical and financial) on candidate DER technologies, DER-CAM minimizes the overall energy cost for a test year by selecting the units to install and determining their hourly operating schedules. In this paper, the capabilities of DER-CAM are enhanced by the inclusion of the option to store recovered low-grade heat. By being able to keep an inventory of heat for use in subsequent periods, sites are able to lower costs even further by reducing off-peak generation and relying on storage. This and other effects of storages are demonstrated by analysis of five typical commercial buildings in San Francisco, California, and an estimate of the cost per unit capacity of heat storage is calculated.

  20. FINAL STAFF PAPER A New Generation of Combined Heat

    E-Print Network [OSTI]

    , distributed generation #12;iv #12;v TABLE OF CONTENTS Page Acknowledgements FINAL STAFF PAPER A New Generation of Combined Heat and Power: Policy Planning. Neff , Bryan. A New Generation of Combined Heat and Power: Policy Planning for 2030. 2012. California

  1. Generator powered electrically heated diesel particulate filter

    DOE Patents [OSTI]

    Gonze, Eugene V; Paratore, Jr., Michael J

    2014-03-18T23:59:59.000Z

    A control circuit for a vehicle powertrain includes a switch that selectivity interrupts current flow between a first terminal and a second terminal. A first power source provides power to the first terminal and a second power source provides power to the second terminal and to a heater of a heated diesel particulate filter (DPF). The switch is opened during a DPF regeneration cycle to prevent the first power source from being loaded by the heater while the heater is energized.

  2. Hydrodynamics, heat transfer and flow boiling instabilities in microchannels†

    E-Print Network [OSTI]

    Barber, Jacqueline Claire

    2010-01-01T23:59:59.000Z

    Boiling in microchannels is a very efficient mode of heat transfer with high heat and mass transfer coefficients achieved. Less pumping power is required for two-phase flows than for single-phase liquid flows to achieve ...

  3. Radio frequency (RF) heated supersonic flow laboratory

    SciTech Connect (OSTI)

    Wantuck, P.; Watanabe, H.

    1990-01-01T23:59:59.000Z

    A unique supersonic flow apparatus which employs an inductively-coupled, radio frequency (RF) torch to supply high enthalpy source gas to the nozzle inlet is described. The main features of this system are the plasma tube, a cooled nozzle assembly, and a combustion/expansion chamber with a heat exchanger. A description of these components with current test data is presented. In addition, a discussion of anticipated experiments utilizing this system is included.

  4. Distributed Generation with Heat Recovery and Storage

    SciTech Connect (OSTI)

    Siddiqui, Afzal S.; Marnay, Chris; Firestone, Ryan M.; Zhou, Nan

    2006-06-16T23:59:59.000Z

    Electricity produced by distributed energy resources (DER)located close to end-use loads has the potential to meet consumerrequirements more efficiently than the existing centralized grid.Installation of DER allows consumers to circumvent the costs associatedwith transmission congestion and other non-energy costs of electricitydelivery and potentially to take advantage of market opportunities topurchase energy when attractive. On-site, single-cycle thermal powergeneration is typically less efficient than central station generation,but by avoiding non-fuel costs of grid power and by utilizing combinedheat and power (CHP) applications, i.e., recovering heat from small-scaleon-site thermal generation to displace fuel purchases, DER can becomeattractive to a strictly cost-minimizing consumer. In previous efforts,the decisions facing typical commercial consumers have been addressedusing a mixed-integer linear program, the DER Customer Adoption Model(DER-CAM). Given the site s energy loads, utility tariff structure, andinformation (both technical and financial) on candidate DER technologies,DER-CAM minimizes the overall energy cost for a test year by selectingthe units to install and determining their hourly operating schedules. Inthis paper, the capabilities of DER-CAM are enhanced by the inclusion ofthe option to store recovered low-grade heat. By being able to keep aninventory of heat for use in subsequent periods, sites are able to lowercosts even further by reducing lucrative peak-shaving generation whilerelying on storage to meet heat loads. This and other effects of storageare demonstrated by analysis of five typical commercial buildings in SanFrancisco, California, USA, and an estimate of the cost per unit capacityof heat storage is calculated.

  5. Billet Heating with the Homopolar Generator

    E-Print Network [OSTI]

    Weldon, W. F.; Keith, R. E.; Weldon, J. M.

    1980-01-01T23:59:59.000Z

    be of immediate applications. benefit to the metal forging and rolling industries The use of pulsed homopolar generators for weld as a power source for billet heating. ing large sections has been described previously.[6,7] The University of Texas Center..., however, includ ing resistance welding and other forms of resistance 74 ESL-IE-80-04-10 Proceedings from the Second Industrial Energy Technology Conference Houston, TX, April 13-16, 1980 Ferromagnetic Conductive Rotor Pancake Wound Field Coil Figure...

  6. FLUID MECHANICS AND HEAT TRANSFER OF ELECTRON FLOW IN SEMICONDUCTORS

    E-Print Network [OSTI]

    Sen, Mihir

    = heat, f = LO-mode, g = LO, h = LA-mode, i = negligible, j = remote heat sink 7/ 70 #12;Heat conductionFLUID MECHANICS AND HEAT TRANSFER OF ELECTRON FLOW IN SEMICONDUCTORS Mihir Sen Department · Shallow water analogy · Vorticity dynamics · Linear stability analysis · Numerical simulations of heat

  7. Hydrodynamics and heat transfer during flow boiling instabilities in a single microchannel

    E-Print Network [OSTI]

    Aussillous, Pascale

    Hydrodynamics and heat transfer during flow boiling instabilities in a single microchannel July 2008 Keywords: Boiling Microchannels Visualisation Flow boiling instabilities Heat transfer a b intensification heat removal. Flow boiling heat transfer in microchannel geometry and the associated flow

  8. A Cross-Flow Ceramic Heat Recuperator for Industrial Heat Recovery†

    E-Print Network [OSTI]

    Gonzalez, J. M.; Cleveland, J. J.; Kohnken, K. H.; Rebello, W. J.

    1980-01-01T23:59:59.000Z

    performance criteria and demonstrate a cross-flow ceramic heat recuperator for high temperature industrial heat recovery applications. The immediate goals of the ceramic recuperator project were to demonstrate a heat exchanger capable of handling high...

  9. TOPAZ: a computer code for modeling heat transfer and fluid flow in arbitrary networks of pipes, flow branches, and vessels

    SciTech Connect (OSTI)

    Winters, W.S.

    1984-01-01T23:59:59.000Z

    An overview of the computer code TOPAZ (Transient-One-Dimensional Pipe Flow Analyzer) is presented. TOPAZ models the flow of compressible and incompressible fluids through complex and arbitrary arrangements of pipes, valves, flow branches and vessels. Heat transfer to and from the fluid containment structures (i.e. vessel and pipe walls) can also be modeled. This document includes discussions of the fluid flow equations and containment heat conduction equations. The modeling philosophy, numerical integration technique, code architecture, and methods for generating the computational mesh are also discussed.

  10. Hamiltonian Thermostats Fail to Promote Heat Flow

    E-Print Network [OSTI]

    Wm. G. Hoover; Carol G. Hoover

    2013-07-16T23:59:59.000Z

    Hamiltonian mechanics can be used to constrain temperature simultaneously with energy. We illustrate the interesting situations that develop when two different temperatures are imposed within a composite Hamiltonian system. The model systems we treat are "phi-4" chains, with quartic tethers and quadratic nearest-neighbor Hooke's-law interactions. This model is known to satisfy Fourier's law. Our prototypical problem sandwiches a Newtonian subsystem between hot and cold Hamiltonian reservoir regions. We have characterized four different Hamiltonian reservoir types. There is no tendency for any of these two-temperature Hamiltonian simulations to transfer heat from the hot to the cold degrees of freedom. Evidently steady heat flow simulations require energy sources and sinks, and are therefore incompatible with Hamiltonian mechanics.

  11. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOE Patents [OSTI]

    Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI); Marsala, Joseph (Glen Ellyn, IL)

    1994-11-29T23:59:59.000Z

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium.

  12. DEVELOPING FLOW AND HEAT TRANSFER IN STRONGLY CURVED DUCTS OF RECTANGULAR CROSS-SECTION

    E-Print Network [OSTI]

    Yee, G.

    2010-01-01T23:59:59.000Z

    DEVELOpiNG FLOW AND HEAT TRANSFER IN STRONGLY CURVED DUCTS9092 Developing Flow and Heat Transfer in Strongly CurvedForced Convection Heat Transfer in Curved Rectangular

  13. Heat-flow reconnaissance of the Gulf Coastal Plain

    SciTech Connect (OSTI)

    Smith, D.L.; Shannon, S.S. Jr.

    1982-04-01T23:59:59.000Z

    Most of the 46 new values of heat flow determined for the Gulf Coastal Plain are in the low to normal range, but heat-flow values averaging 1.8 heat-flow unit (HFU) were obtained in Claiborne, Ouachita, and Union parishes, Louisiana. Moreover, a zone of relatively high heat-flow values and steep thermal gradients (35 to 46/sup 0/C/km) extends from northern Louisiana into southwestern Mississippi. Also near Pensacola, Florida, temperatures of 50/sup 0/C at 1-km depth have been extrapolated from thermal gradients. Future development of low-grade geothermal resources may be warranted in these areas.

  14. Heat flow and microearthquake studies, Coso Geothermal Area,...

    Open Energy Info (EERE)

    Final report Jump to: navigation, search OpenEI Reference LibraryAdd to library Book: Heat flow and microearthquake studies, Coso Geothermal Area, China Lake, California....

  15. Applications of the Strong Heat Transformation by Pulse Flow in the Shell and Tube Heat Exchanger†

    E-Print Network [OSTI]

    Chen, Y.; Zhao, J.

    2006-01-01T23:59:59.000Z

    This article deals with the heat exchange coefficient varied with pulse frequency in the pulsation tube with different flow forms. The findings show that heat can be exchanged coefficient with the pulse frequency, and it has an optimal frequency...

  16. Applications of the Strong Heat Transformation by Pulse Flow in the Shell and Tube Heat Exchanger

    E-Print Network [OSTI]

    Chen, Y.; Zhao, J.

    2006-01-01T23:59:59.000Z

    This article deals with the heat exchange coefficient varied with pulse frequency in the pulsation tube with different flow forms. The findings show that heat can be exchanged coefficient with the pulse frequency, and it has an optimal frequency...

  17. Heat transfer to impacting drops and post critical heat flux dispersed flow

    E-Print Network [OSTI]

    Kendall, Gail E.

    1978-01-01T23:59:59.000Z

    Heat transfer to drops impacting on a hot surface is examined in context of dispersions of flowing, boiling fluids. The liquid contribution to heat transfer from a hot tube to a two-phase dispersion is formulated in terms ...

  18. Heat exchanger for power generation equipment

    DOE Patents [OSTI]

    Nirmalan, Nirm Velumylm; Bowman, Michael John

    2005-06-14T23:59:59.000Z

    A heat exchanger for a turbine is provided wherein the heat exchanger comprises a heat transfer cell comprising a sheet of material having two opposed ends and two opposed sides. In addition, a plurality of concavities are disposed on a surface portion of the sheet of material so as to cause hydrodynamic interactions and affect a heat transfer rate of the turbine between a fluid and the concavities when the fluid is disposed over the concavities.

  19. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOE Patents [OSTI]

    Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)

    1998-07-21T23:59:59.000Z

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration.

  20. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOE Patents [OSTI]

    Phillips, B.A.; Zawacki, T.S.

    1998-07-21T23:59:59.000Z

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration. 5 figs.

  1. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOE Patents [OSTI]

    Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)

    1996-12-03T23:59:59.000Z

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium. A combination of weak and rich liquor working solution is used as the heat transfer medium.

  2. QUANTIFYING MAGNETIC RECONNECTION AND THE HEAT IT GENERATES Dana Longcope

    E-Print Network [OSTI]

    Longcope, Dana

    in many aspects of coronal activity including the general process of coronal heating. Magnetic of that structure. Key words: Magnetic reconnection. 1. INTRODUCTION Models for heating the solar coronaQUANTIFYING MAGNETIC RECONNECTION AND THE HEAT IT GENERATES Dana Longcope Department of Physics

  3. Sorption heat engines: simple inanimate negative entropy generators

    E-Print Network [OSTI]

    Anthonie W. J. Muller; Dirk Schulze-Makuch

    2005-12-18T23:59:59.000Z

    The name 'sorption heat engines' is proposed for simple negative entropy generators that are driven by thermal cycling and work on alternating adsorption and desorption. These generators are in general not explicitly recognized as heat engines. Their mechanism is applicable to the fields of engineering, physics, chemistry, geology, and biology, in particular the origin of life. Four kinds of sorption heat engines are distinguished depending on the occurrence of changes in the adsorbent or adsorbate during the thermal cycle.

  4. Distributed Generation with Heat Recovery and Storage

    E-Print Network [OSTI]

    Siddiqui, Afzal S.; Marnay, Chris; Firestone, Ryan M.; Zhou, Nan

    2008-01-01T23:59:59.000Z

    tiles for thermal energy storage,Ē working paper, Colorado1991). Wallboard with latent heat storage for passive solarR. (2000). Thermal energy storage for space cooling, Pacific

  5. Thermionic generator module with heat pipes

    SciTech Connect (OSTI)

    Horner-Richardson, K.; Ernst, D.M.

    1993-06-15T23:59:59.000Z

    A thermionic converter module is described comprising: a first heat pipe with an annular casing which has a first surface located on an inside surface of the annular casing, at least part of the first surface of the casing of the first heat pipe having constructed upon it a thermionic converter emitter located so that heat will be transferred by conduction from the first heat pipe casing to the thermionic converter emitter; a second heat pipe with a casing which has a second surface, the second surface being located within the first surface of the annular casing of the first heat pipe so that it is surrounded by the first surface; a thermionic converter collector located so as to transfer heat by conduction to the second surface of the casing of the second heat pipe with the thermionic converter collector being adjacent to the thermionic converter emitter but being separated from the thermionic converter emitter by an inter electrode space; and end fitting structures located so that, with the thermionic converter collector and the thermionic converter emitter, they complete an enclosure around the inter electrode space and form an evacuated enclosure within which are located the thermionic converter collector and the thermionic converter emitter.

  6. Distributed Generation with Heat Recovery and Storage

    E-Print Network [OSTI]

    Siddiqui, Afzal S.; Marnay, Chris; Firestone, Ryan M.; Zhou, Nan

    2008-01-01T23:59:59.000Z

    Space-Heating Supply Hour Load (kW) Storage CHP NG Fig. 14Space-Heating Supply Load (kW) Storage Hour CHP NG Fig. 15Supply Load (kW) Storage CHP NG Hour Fig. 16 July Weekday

  7. Numerical Study of Flow and Heat Transfer in Rotating Microchannels

    E-Print Network [OSTI]

    Roy, Pratanu

    2014-10-07T23:59:59.000Z

    Investigation of fluid flow and heat transfer in rotating microchannels is important for centrifugal microfluidics, which has emerged as an advanced technique in biomedical applications and chemical separations. The centrifugal force...

  8. 16 Heat Transfer and Air Flow in a Domestic Refrigerator

    E-Print Network [OSTI]

    Paris-Sud XI, Universitť de

    445 16 Heat Transfer and Air Flow in a Domestic Refrigerator Onrawee Laguerre UMR Gťnie Industriel...............................................447 16.2.1 Studies in Domestic Refrigerators...................................................................................... 451 16.3 Cold Production System in Domestic Refrigerators

  9. Temperatures, heat flow, and water chemistry from drill holes...

    Open Energy Info (EERE)

    Temperatures, heat flow, and water chemistry from drill holes in the Raft River geothermal system, Cassia County, Idaho Jump to: navigation, search OpenEI Reference LibraryAdd to...

  10. Distributed Generation with Heat Recovery and Storage

    E-Print Network [OSTI]

    Siddiqui, Afzal S.; Marnay, Chris; Firestone, Ryan M.; Zhou, Nan

    2008-01-01T23:59:59.000Z

    Only Load Electricity Generation By Fuel in the U.S.electricity generation from most sources, except oil, is growing to meet the growing demand and that fossil fuels

  11. Effect on Non-Uniform Heat Generation on Thermionic Reactions

    SciTech Connect (OSTI)

    Schock, Alfred

    2012-01-19T23:59:59.000Z

    The penalty resulting from non-uniform heat generation in a thermionic reactor is examined. Operation at sub-optimum cesium pressure is shown to reduce this penalty, but at the risk of a condition analogous to burnout. For high pressure diodes, a simple empirical correlation between current, voltage and heat flux is developed and used to analyze the performance penalty associated with two different heat flux profiles, for series-and parallel-connected converters. The results demonstrate that series-connected converters require much finer power flattening than parallel converters. For example, a Ī10% variation in heat generation across a series array can result in a 25 to 50% power penalty.

  12. Enhanced two phase flow in heat transfer systems

    DOE Patents [OSTI]

    Tegrotenhuis, Ward E; Humble, Paul H; Lavender, Curt A; Caldwell, Dustin D

    2013-12-03T23:59:59.000Z

    A family of structures and designs for use in devices such as heat exchangers so as to allow for enhanced performance in heat exchangers smaller and lighter weight than other existing devices. These structures provide flow paths for liquid and vapor and are generally open. In some embodiments of the invention, these structures can also provide secondary heat transfer as well. In an evaporate heat exchanger, the inclusion of these structures and devices enhance the heat transfer coefficient of the evaporation phase change process with comparable or lower pressure drop.

  13. Heating Cooling Flows with Weak Shock Waves

    E-Print Network [OSTI]

    W. G. Mathews; A. Faltenbacher; F. Brighenti

    2005-11-05T23:59:59.000Z

    The discovery of extended, approximately spherical weak shock waves in the hot intercluster gas in Perseus and Virgo has precipitated the notion that these waves may be the primary heating process that explains why so little gas cools to low temperatures. This type of heating has received additional support from recent gasdynamical models. We show here that outward propagating, dissipating waves deposit most of their energy near the center of the cluster atmosphere. Consequently, if the gas is heated by (intermittent) weak shocks for several Gyrs, the gas within 30-50 kpc is heated to temperatures that far exceed observed values. This heating can be avoided if dissipating shocks are sufficiently infrequent or weak so as not to be the primary source of global heating. Local PV and viscous heating associated with newly formed X-ray cavities are likely to be small, which is consistent with the low gas temperatures generally observed near the centers of groups and clusters where the cavities are located.

  14. Control of reactor coolant flow path during reactor decay heat removal

    DOE Patents [OSTI]

    Hunsbedt, Anstein N. (Los Gatos, CA)

    1988-01-01T23:59:59.000Z

    An improved reactor vessel auxiliary cooling system for a sodium cooled nuclear reactor is disclosed. The sodium cooled nuclear reactor is of the type having a reactor vessel liner separating the reactor hot pool on the upstream side of an intermediate heat exchanger and the reactor cold pool on the downstream side of the intermediate heat exchanger. The improvement includes a flow path across the reactor vessel liner flow gap which dissipates core heat across the reactor vessel and containment vessel responsive to a casualty including the loss of normal heat removal paths and associated shutdown of the main coolant liquid sodium pumps. In normal operation, the reactor vessel cold pool is inlet to the suction side of coolant liquid sodium pumps, these pumps being of the electromagnetic variety. The pumps discharge through the core into the reactor hot pool and then through an intermediate heat exchanger where the heat generated in the reactor core is discharged. Upon outlet from the heat exchanger, the sodium is returned to the reactor cold pool. The improvement includes placing a jet pump across the reactor vessel liner flow gap, pumping a small flow of liquid sodium from the lower pressure cold pool into the hot pool. The jet pump has a small high pressure driving stream diverted from the high pressure side of the reactor pumps. During normal operation, the jet pumps supplement the normal reactor pressure differential from the lower pressure cold pool to the hot pool. Upon the occurrence of a casualty involving loss of coolant pump pressure, and immediate cooling circuit is established by the back flow of sodium through the jet pumps from the reactor vessel hot pool to the reactor vessel cold pool. The cooling circuit includes flow into the reactor vessel liner flow gap immediate the reactor vessel wall and containment vessel where optimum and immediate discharge of residual reactor heat occurs.

  15. Polymer Effects on Heat Transport in Laminar Boundary Layer Flow

    E-Print Network [OSTI]

    Roberto Benzi; Emily S. C. Ching; Vivien W. S. Chu

    2011-04-27T23:59:59.000Z

    We consider a laminar Blasius boundary-layer flow above a slightly heated horizontal plate and study the effect of polymer additives on the heat transport. We show that the action of the polymers can be understood as a space-dependent effective viscosity that first increases from the zero-shear value then decreases exponentially back to the zero-shear value as one moves away from the boundary. We find that with such an effective viscosity, both the horizontal and vertical velocities near the plate are decreased thus leading to an increase in the friction drag and a decrease in the heat transport in the flow.

  16. Supersonic combustion of a transverse injected H sub 2 jet in a radio frequency heated flow

    SciTech Connect (OSTI)

    Wantuck, P.J.; Tennant, R.A.; Watanabe, H.H.

    1991-01-01T23:59:59.000Z

    The combustion of a single hydrogen jet, normally injected into a radio frequency (RF) heated, oxidant-containing, supersonic flow, has been established to characterize the chemical and fluid dynamic phenomena associated with the reaction process and ultimately validate the predictive capability of computational computer dynamic (CFD) codes. The experimental system employed for this study is unique in that it uses an electrodeless, inductively coupled plasma tube to generate the high temperature oxidant-containing gas for subsequent nozzle expansion. Advantages of an RF heated flow system include reduced free-stream chemical contamination, continuous operation, and relative ease of integration into a typical flow laboratory environment. A description of the system utilized for this study is presented including preliminary results of the reactive flow characterization. In addition, the use of the laser-based diagnostic techniques, such as planar laser-induced fluorescence (PLIF), for measuring flow properties is also discussed. 8 refs., 7 figs.

  17. Power Generation From Waste Heat Using Organic Rankine Cycle Systems

    E-Print Network [OSTI]

    Prasad, A.

    1980-01-01T23:59:59.000Z

    universal bottoming cycle that can convert the energy in waste heat streams into usable shaft power. The nominal rating of the unit is 600 KWe or 900 SHP. The basic bottoming cycle concept is shown in Figure I. GAS TURBINE -, Y. DIESEL PROCESS HEAT... in Figure 2. The diverter valve directs the waste heat stream through the vaporizer. The working fluid is boiled and slightly superheated in the vaporizer. The superheated vapor expands through the turbine, generating mechanical power. This expansion...

  18. Thermoelectric Generators for Automotive Waste Heat Recovery Systems Part II: Parametric Evaluation

    E-Print Network [OSTI]

    Xu, Xianfan

    Thermoelectric Generators for Automotive Waste Heat Recovery Systems Part II: Parametric Evaluation been proposed to model thermoelectric generators (TEGs) for automotive waste heat recovery. Details: Thermoelectric generators, waste heat recovery, automotive exhaust, skutterudites INTRODUCTION In part I

  19. STOCHASTIC FLOW SEQUENCE GENERATION AND ASPINALL UNIT OPERATIONS

    E-Print Network [OSTI]

    to incorporate paleo #12;iv reconstructed data. The selected methods are then employed to generate syntheticSTOCHASTIC FLOW SEQUENCE GENERATION AND ASPINALL UNIT OPERATIONS By KENNETH C NOWAK B Flow Sequence Generation and Aspinall Unit Operations written by Kenneth C Nowak has been approved

  20. Generating expansion model incorporating compact DC power flow equations

    SciTech Connect (OSTI)

    Nderitu, D.G.; Sparrow, F.T.; Yu, Z. [Purdue Inst. for Interdisciplinary Engineering Studies, West Lafayette, IN (United States)

    1998-12-31T23:59:59.000Z

    This paper presents a compact method of incorporating the spatial dimension into the generation expansion problem. Compact DC power flow equations are used to provide real-power flow coordination equations. Using these equations the marginal contribution of a generator to th total system loss is formulated as a function of that generator`s output. Incorporating these flow equations directly into the MIP formulation of the generator expansion problem results in a model that captures a generator`s true net marginal cost, one that includes both the cost of generation and the cost of transport. This method contrasts with other methods that iterate between a generator expansion model and an optimal power flow model. The proposed model is very compact and has very good convergence performance. A case study with data from Kenya is used to provide a practical application to the model.

  1. Bubbles as tracers of heat input to cooling flows

    E-Print Network [OSTI]

    J. Binney; F. Alouani Bibi; H. Omma

    2007-01-31T23:59:59.000Z

    We examine the distribution of injected energy in three-dimensional, adaptive-grid simulations of the heating of cooling flows. We show that less than 10 percent of the injected energy goes into bubbles. Consequently, the energy input from the nucleus is underestimated by a factor of order 6 when it is taken to be given by PVgamma/(gamma-1), where P and V are the pressure and volume of the bubble, and gamma the ratio of principal specific heats.

  2. Heat flow and geothermal studies in the state of Washington

    SciTech Connect (OSTI)

    Blackwell, D.D.; Steele, J.L.; Kelley, S.A.

    1985-08-01T23:59:59.000Z

    Existing geothermal gradient and heat flow data for the state of Washington are summarized. In addition, information on mean-annual ground surface temperatures is included. The data consist of accurate, detailed temperature-depth measurements in selected available holes throughout the state of Washington made between 1979 and 1982. Measurements of thermal conductivity on selected rock samples from these drill holes and ancillary information required to assess the significance of the data and calculate heat flow values were obtained as well. Information is presented on the mean-annual ground-surface temperatures throughout the state of Washington. 32 refs., 15 figs., 4 tabs.

  3. Brine flow in heated geologic salt.

    SciTech Connect (OSTI)

    Kuhlman, Kristopher L.; Malama, Bwalya

    2013-03-01T23:59:59.000Z

    This report is a summary of the physical processes, primary governing equations, solution approaches, and historic testing related to brine migration in geologic salt. Although most information presented in this report is not new, we synthesize a large amount of material scattered across dozens of laboratory reports, journal papers, conference proceedings, and textbooks. We present a mathematical description of the governing brine flow mechanisms in geologic salt. We outline the general coupled thermal, multi-phase hydrologic, and mechanical processes. We derive these processes' governing equations, which can be used to predict brine flow. These equations are valid under a wide variety of conditions applicable to radioactive waste disposal in rooms and boreholes excavated into geologic salt.

  4. Billet Heating with the Homopolar Generator

    E-Print Network [OSTI]

    Weldon, W. F.; Keith, R. E.; Weldon, J. M.

    1980-01-01T23:59:59.000Z

    velocity is limited by brush life considerations to 200 m/s (v = Rw = 200 m/s) so that E = 2.461 x 10 8 R 2 t Homopo1ar generators storing from a few ki10jou1es (10 3 joules) to several gigajou1es (10 9 joules) have been designed. UT-CEM has a 5 MJ... to 2400?F V = 2.95 x 10-5(*)-e. where V = voltage required (V) ( *)= current dens ity requi red (..A-) . 2 1 n. l = billet length (in.) ;~.. As an example of how to use this information, consider a 4 inch diameter, 24 inch long steel billet...

  5. Techno-economic analysis of using corn stover to supply heat and power to a corn ethanol plant - Part 2: Cost of heat and power generation systems

    SciTech Connect (OSTI)

    Mani, Sudhagar [University of Georgia; Sokhansanj, Shahabaddine [ORNL; Togore, Sam [U.S. Department of Energy; Turhollow Jr, Anthony F [ORNL

    2010-03-01T23:59:59.000Z

    This paper presents a techno-economic analysis of corn stover fired process heating (PH) and the combined heat and power (CHP) generation systems for a typical corn ethanol plant (ethanol production capacity of 170 dam3). Discounted cash flow method was used to estimate both the capital and operating costs of each system and compared with the existing natural gas fired heating system. Environmental impact assessment of using corn stover, coal and natural gas in the heat and/or power generation systems was also evaluated. Coal fired process heating (PH) system had the lowest annual operating cost due to the low fuel cost, but had the highest environmental and human toxicity impacts. The proposed combined heat and power (CHP) generation system required about 137 Gg of corn stover to generate 9.5 MW of electricity and 52.3 MW of process heat with an overall CHP efficiency of 83.3%. Stover fired CHP system would generate an annual savings of 3.6 M$ with an payback period of 6 y. Economics of the coal fired CHP system was very attractive compared to the stover fired CHP system due to lower fuel cost. But the greenhouse gas emissions per Mg of fuel for the coal fired CHP system was 32 times higher than that of stover fired CHP system. Corn stover fired heat and power generation system for a corn ethanol plant can improve the net energy balance and add environmental benefits to the corn to ethanol biorefinery.

  6. Flow instability and critical heat flux in a ribbed annulus

    SciTech Connect (OSTI)

    Yang, B.W.; Dougherty, T.; Fighetti, C.; Kokolis, S.; Reddy, G.D. [Columbia Univ., New York, NY (United States); McAssey, E.V. Jr. [Villanova Univ., PA (United States); Coutts, A. [Westinghouse Savannah River Co., Aiken, SC (United States)

    1993-11-01T23:59:59.000Z

    An experimental program has been conducted to determine the onset of flow instability point in a heated annulus which is divided into four sub channels by non-conducting ribs. The onset of flow instability is identified by the minimum point in the pressure drop-velocity curve. Comparison with a ribless annulus show that the presence of ribs increases the minimum point velocity. In addition, data are presented which show that under certain conditions premature CHF can be induced by the ribs.

  7. Geothermal Well and Heat Flow Data for the United States (Southern Methodist University (SMU) Geothermal Laboratory)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Blackwell, D.D. and others

    Southern Methodist University makes two databases and several detailed maps available. The Regional Heat Flow Database for the United States contains information on primarily regional or background wells that determine the heat flow for the United States; temperature gradients and conductivity are used to generate heat flow measurements. Information on geology of the location, porosity, thermal conductivity, water table depth, etc. are also included when known. There are usually three data files for each state or region. The first files were generated in 1989 for the data base creating the Decade of North America Geology (DNAG) Geothermal Map. The second set is from 1996 when the data base was officially updated for the Department of Energy. The third set is from 1999 when the Western U.S. High Temperature Geothermal data base was completed. As new data is received, the files continue to be updated. The second major resource is the Western Geothermal Areas Database, a database of over 5000 wells in primarily high temperature geothermal areas from the Rockies to the Pacific Ocean. The majority of the data are from company documents, well logs, and publications with drilling dates ranging from 1960 to 2000. Many of the wells were not previously accessible to the public. Users will need to register, but will then have free, open access to the databases. The contents of each database can be viewed and downloaded as Excel spreadsheets. See also the heat flow maps at http://www.smu.edu/geothermal/heatflow/heatflow.htm

  8. Heat transfer and pressure drop of supercritical carbon dioxide flowing in several printed circuit heat exchanger channel patterns

    SciTech Connect (OSTI)

    Carlson, M. [Univ. of Wisconsin - Madison, 839 Engineering Research Building, 1500 Engineering Drive, Madison, WI 53706 (United States); Kruizenga, A. [Sandia National Laboratory (United States); Anderson, M.; Corradini, M. [Univ. of Wisconsin - Madison, 839 Engineering Research Building, 1500 Engineering Drive, Madison, WI 53706 (United States)

    2012-07-01T23:59:59.000Z

    Closed-loop Brayton cycles using supercritical carbon dioxide (SCO{sub 2}) show potential for use in high-temperature power generation applications including High Temperature Gas Reactors (HTGR) and Sodium-Cooled Fast Reactors (SFR). Compared to Rankine cycles SCO{sub 2} Brayton cycles offer similar or improved efficiency and the potential for decreased capital costs due to a reduction in equipment size and complexity. Compact printed-circuit heat exchangers (PCHE) are being considered as part of several SCO{sub 2} Brayton designs to further reduce equipment size with increased energy density. Several designs plan to use a gas cooler operating near the pseudo-critical point of carbon dioxide to benefit from large variations in thermophysical properties, but further work is needed to validate correlations for heat transfer and pressure-drop characteristics of SCO{sub 2} flows in candidate PCHE channel designs for a variety of operating conditions. This paper presents work on experimental measurements of the heat transfer and pressure drop behavior of miniature channels using carbon dioxide at supercritical pressure. Results from several plate geometries tested in horizontal cooling-mode flow are presented, including a straight semi-circular channel, zigzag channel with a bend angle of 80 degrees, and a channel with a staggered array of extruded airfoil pillars modeled after a NACA 0020 airfoil with an 8.1 mm chord length facing into the flow. Heat transfer coefficients and bulk temperatures are calculated from measured local wall temperatures and local heat fluxes. The experimental results are compared to several methods for estimating the friction factor and Nusselt number of cooling-mode flows at supercritical pressures in millimeter-scale channels. (authors)

  9. New geothermal heat extraction process to deliver clean power generation

    ScienceCinema (OSTI)

    Pete McGrail

    2012-12-31T23:59:59.000Z

    A new method for capturing significantly more heat from low-temperature geothermal resources holds promise for generating virtually pollution-free electrical energy. Scientists at the Department of Energys Pacific Northwest National Laboratory will determine if their innovative approach can safely and economically extract and convert heat from vast untapped geothermal resources. The goal is to enable power generation from low-temperature geothermal resources at an economical cost. In addition to being a clean energy source without any greenhouse gas emissions, geothermal is also a steady and dependable source of power.

  10. Self-heating in kinematically complex magnetohydrodynamic flows

    E-Print Network [OSTI]

    Osmanov, Zaza; Poedts, Stefaan

    2012-01-01T23:59:59.000Z

    The non-modal self-heating mechanism driven by the velocity shear in kinematically complex magnetohydrodynamic (MHD) plasma flows is considered. The study is based on the full set of MHD equations including dissipative terms. The equations are linearized and unstable modes in the flow are looked for. Two different cases are specified and studied: (a) the instability related to an exponential evolution of the wave vector; and (b) the parametric instability, which takes place when the components of the wave vector evolve in time periodically. By examining the dissipative terms, it is shown that the self-heating rate provided by viscous damping is of the same order of magnitude as that due to the magnetic resistivity. It is found that the heating efficiency of the exponential instability is higher than that of the parametric instability.

  11. The heating of the cooling flow (The feedback effervescent heating model)

    E-Print Network [OSTI]

    Nasser Mohamed Ahmed

    2007-10-13T23:59:59.000Z

    The standard cooling flow model has predicted a large amount of cool gas in the clusters of galaxies. The failure of the Chandra and XXM-Newton telescopes to detect cooling gas (below 1-2 keV) in clusters of galaxies has suggested that some heating process must work to suppress the cooling. The most likely heating source is the heating by AGNs. There are many heating mechanisms, but we will adopt the effervescent heating model which is a result of the interaction of the bubbles inflated by AGN with the intra-cluster medium(ICM). Using the FLASH code, we have carried out time dependent simulations to investigate the effect of the heating on the suppression of the cooling in cooling flow clusters. We have found that the effervescent heating model can not balance the radiative cooling and it is an artificial model. Furthermore, the effervescent heating is a function of the ICM pressure gradient but the cooling is proportional to the gas density square and square root of the gas temperature.

  12. .Heat Generation Patterns and Temperature Profiles in_ Electroslag Welding

    E-Print Network [OSTI]

    Eagar, Thomas W.

    l .Heat Generation Patterns and Temperature Profiles in_ Electroslag Welding ) ∑ T. DEBROY, J in the slag and metal phases for an electroslag welding system. It is shown that the current is significantly larger for the electroslag welding process than that of the electroslao refinino process operating

  13. Probing and Controlling Photothermal Heat Generation in Plasmonic Nanostructures

    E-Print Network [OSTI]

    Simaan, Nabil

    thermal hotspots. In the present study, new methods for designing and thermally probing thermoplasmonic suitable for heat generation compared with its more well-known complementary structure, the bow-tie antenna. We also demonstrate that highly localized and enhanced thermal hot spots can be realized

  14. Macroscopic implications from phase space dynamics of tokamak turbulence : relaxation, transport, and flow generation

    E-Print Network [OSTI]

    Kosuga, Yusuke

    2012-01-01T23:59:59.000Z

    Turbulent plasma and flow generation . . . . . . . . . . .of Intrinsic Rotation Generation in Tokamaks . . 2.12.2.2 Flow generation and stationary state . . . . . 2.3

  15. Heat flow during the autogenous GTA welding of pipes

    SciTech Connect (OSTI)

    Kou, S.; Le, Y.

    1984-06-01T23:59:59.000Z

    A theoretical and experimental study of heat flow during the welding of pipes was carried out. The theoretical part of the study involves the development of two finite difference computer models: one for describing steady state, 3-dimensional heat flow during seam welding, the other for describing unsteady state, 3-dimensional heat flow during girth welding. The experimental part of the study, on the other hand, includes: measurement of the thermal response of the pipe with a high speed data acquisition system, determination of the arc efficiency with a calorimeter, and examination of the fusion boundary of the resultant weld. The experimental results were compared with the calculated ones, and the agreement was excellent in the case of seam welding and reasonably good in the case of girth welding. Both the computer models and experiments confirmed that, under a constant heat input and welding speed, the size of the fusion zone remains unchanged in seam welding but continues to increase in girth welding of pipes of small diameters. It is expected that the unsteady state model developed can be used to provide optimum conditions for girth welding, so that uniform weld beads can be obtained and weld defects such as lack of fusion and sagging can be avoided.

  16. A visualization comparison of convective flow boiling heat transfer augmentation devices

    E-Print Network [OSTI]

    Lundy, Brian Franklin

    1998-01-01T23:59:59.000Z

    The qualitative effects of inset-table heat transfer phics. augmentation devices on vertical in-tube convective flow boiling flow regimes, transition mechanisms, and heat transfer are presented in this study. Three twisted tapes with twist ratios...

  17. Microcomputer analysis of regenerative heat exchangers for oscillating flow

    SciTech Connect (OSTI)

    Hutchinson, R.A.; Lyke, S.E.

    1987-03-01T23:59:59.000Z

    Regenerative heat exchangers for use in oscillating flows such as those occurring in Stirling engines present considerable analytical problems to the thermal engineer. A simplified finite element analysis has been implemented in a spreadsheet, providing improved access to analytical assumptions and allowing parametric analysis of current heat transfer data. In addition, an irreversibility analysis has been implemented using the thermal and friction results in the spreadsheet. It is suited for evaluation and insights into loss tradeoffs inside operating regenerators, to suggest new regenerator design concepts, and to focus experimental work. 22 refs., 13 figs.

  18. COMPUTATION OF TWO-PHASE FLOW IN STEAM GENERATOR

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    COMPUTATION OF TWO-PHASE FLOW IN STEAM GENERATOR USING DOMAIN DECOMPOSITION AND LOCAL ZOOM METHODS Abstract We present ow simulations in the Steam Generator of a pressurized water nuclear reactor using coherence between the zoom and the full domain. Key words: Steam Generator, Zoom, Domain Decomposition

  19. Spherical collapse with heat flow and without horizon

    E-Print Network [OSTI]

    A. Banerjee; S. Chatterjee; N. Dadhich

    2002-09-10T23:59:59.000Z

    We present a class of solutions for a heat conducting fluid sphere, which radiates energy during collapse without the appearance of horizon at the boundary at any stage of the collapse. A simple model shows that there is no accumulation of energy due to collapse since it radiates out at the same rate as it is being generated.

  20. Assessment of next generation nuclear plant intermediate heat exchanger design.

    SciTech Connect (OSTI)

    Majumdar, S.; Moisseytsev, A.; Natesan, K.; Nuclear Engineering Division

    2008-10-17T23:59:59.000Z

    The Next Generation Nuclear Plant (NGNP), which is an advanced high temperature gas reactor (HTGR) concept with emphasis on production of both electricity and hydrogen, involves helium as the coolant and a closed-cycle gas turbine for power generation with a core outlet/gas turbine inlet temperature of 900-1000 C. In the indirect cycle system, an intermediate heat exchanger is used to transfer the heat from primary helium from the core to the secondary fluid, which can be helium, nitrogen/helium mixture, or a molten salt. The system concept for the vary high temperature reactor (VHTR) can be a reactor based on the prismatic block of the GT-MHR developed by a consortium led by General Atomics in the U.S. or based on the PBMR design developed by ESKOM of South Africa and British Nuclear Fuels of U.K. This report has made an assessment on the issues pertaining to the intermediate heat exchanger (IHX) for the NGNP. A detailed thermal hydraulic analysis, using models developed at ANL, was performed to calculate heat transfer, temperature distribution, and pressure drop. Two IHX designs namely, shell and straight tube and compact heat exchangers were considered in an earlier assessment. Helical coil heat exchangers were analyzed in the current report and the results were compared with the performance features of designs from industry. In addition, a comparative analysis is presented between the shell and straight tube, helical, and printed circuit heat exchangers from the standpoint of heat exchanger volume, primary and secondary sides pressure drop, and number of tubes. The IHX being a high temperature component, probably needs to be designed using ASME Code Section III, Subsection NH, assuming that the IHX will be classified as a class 1 component. With input from thermal hydraulic calculations performed at ANL, thermal conduction and stress analyses were performed for the helical heat exchanger design and the results were compared with earlier-developed results on shell and straight tube and printed circuit heat exchangers.

  1. Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow

    E-Print Network [OSTI]

    Boyer, Edmond

    Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S modeling of the turbulent flow in a rotor-stator cavity subjected to a superimposed throughflow with heat the dynamical effects from the heat transfer process. The fluid flow in an enclosed disk system with axial

  2. FLIHY EXPERIMENTAL FACILITIES FOR STUDYING OPEN CHANNEL TURBULENT FLOWS AND HEAT TRANSFER

    E-Print Network [OSTI]

    California at Los Angeles, University of

    1 FLIHY EXPERIMENTAL FACILITIES FOR STUDYING OPEN CHANNEL TURBULENT FLOWS AND HEAT TRANSFER B was constructed at UCLA to study open channel turbulent flow and heat transfer of low-thermal and low supercritical flow regimes (Fr>1), in which the surface waves are amplified and heat transfer is enhanced due

  3. Numeric Simulation of Heat Transfer and Electrokinetic Flow in an Electroosmosis-Based

    E-Print Network [OSTI]

    Le Roy, Robert J.

    Numeric Simulation of Heat Transfer and Electrokinetic Flow in an Electroosmosis-Based Continuous is dedicated to under- standing the fluid flow and heat transfer mechanisms occurring in continuous flow PCR are discussed in detail. The importance of each heat transfer mechanism for different situations is also

  4. FliHy experimental facilities for studying open channel turbulent flows and heat transfer

    E-Print Network [OSTI]

    Abdou, Mohamed

    FliHy experimental facilities for studying open channel turbulent flows and heat transfer B. Freeze) facility was constructed at UCLA to study open channel turbulent flow and heat transfer of low supercritical flow regimes (Fr /1), in which the surface waves are amplified and heat transfer is enhanced due

  5. Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with

    E-Print Network [OSTI]

    Paris-Sud XI, Universitť de

    Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with partial-Newtonian boundary layer flow and heat transfer over an exponentially stretch- ing sheet with partial slip boundary. The heat transfer analysis has been carried out for two heating processes, namely (i) with prescribed sur

  6. Heat transport by laminar boundary layer flow with polymers

    E-Print Network [OSTI]

    Roberto Benzi; Emily S. C. Ching.; Vivien W. S. Chu

    2011-04-23T23:59:59.000Z

    Motivated by recent experimental observations, we consider a steady-state Prandtl-Blasius boundary layer flow with polymers above a slightly heated horizontal plate and study how the heat transport might be affected by the polymers. We discuss how a set of equations can be derived for the problem and how these equations can be solved numerically by an iterative scheme. By carrying out such a scheme, we find that the effect of the polymers is equivalent to producing a space-dependent effective viscosity that first increases from the zero-shear value at the plate then decreases rapidly back to the zero-shear value far from the plate. We further show that such an effective viscosity leads to an enhancement in the drag, which in turn leads to a reduction in heat transport.

  7. Conductive and convective heat transfer in fluid flows between differentially heated and rotating cylinders

    E-Print Network [OSTI]

    Lopez, Jose M; Avila, Marc

    2015-01-01T23:59:59.000Z

    The flow of fluid confined between a heated rotating cylinder and a cooled stationary cylinder is a canonical experiment for the study of heat transfer in engineering. The theoretical treatment of this system is greatly simplified if the cylinders are assumed to be of infinite length or periodic in the axial direction, in which cases heat transfer occurs only through conduction as in a solid. We here investigate numerically heat transfer and the onset of turbulence in such flows by using both periodic and no-slip boundary conditions in the axial direction. We obtain a simple linear criterion that determines whether the infinite-cylinder assumption can be employed. The curvature of the cylinders enters this linear relationship through the slope and additive constant. For a given length-to-gap aspect ratio there is a critical Rayleigh number beyond which the laminar flow in the finite system is convective and so the behaviour is entirely different from the periodic case. The criterion does not depend on the Pra...

  8. Generation of acoustic-gravity waves in ionospheric HF heating experiments : simulating large-scale natural heat sources

    E-Print Network [OSTI]

    Pradipta, Rezy

    2012-01-01T23:59:59.000Z

    In this thesis, we investigate the potential role played by large-scale anomalous heat sources (e.g. prolonged heat wave events) in generating acoustic-gravity waves (AGWs) that might trigger widespread plasma turbulence ...

  9. Continued development of a semianalytical solution for two-phase fluid and heat flow in a porous medium

    SciTech Connect (OSTI)

    Doughty, C.; Pruess, K. [Lawrence Berkeley Lab., CA (United States)

    1991-06-01T23:59:59.000Z

    Over the past few years the authors have developed a semianalytical solution for transient two-phase water, air, and heat flow in a porous medium surrounding a constant-strength linear heat source, using a similarity variable {eta} = r/{radical}t. Although the similarity transformation approach requires a simplified geometry, all the complex physical mechanisms involved in coupled two-phase fluid and heat flow can be taken into account in a rigorous way, so that the solution may be applied to a variety of problems of current interest. The work was motivated by adverse to predict the thermohydrological response to the proposed geologic repository for heat-generating high-level nuclear wastes at Yucca Mountain, Nevada, in a partially saturated, highly fractured volcanic formation. The paper describes thermal and hydrologic conditions near the heat source; new features of the model; vapor pressure lowering; and the effective-continuum representation of a fractured/porous medium.

  10. Thermoelectric Generators for Automotive Waste Heat Recovery Systems Part I: Numerical Modeling

    E-Print Network [OSTI]

    Xu, Xianfan

    Thermoelectric Generators for Automotive Waste Heat Recovery Systems Part I: Numerical Modeling (TEG) designed for automotive waste heat recovery systems. This model is capable of computing bismuth telluride are considered for thermoelectric modules (TEMs) for conversion of waste heat from

  11. High Temperature Fuel Cell Tri-Generation of Power, Heat & H2...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Temperature Fuel Cell Tri-Generation of Power, Heat & H2 from Biogas High Temperature Fuel Cell Tri-Generation of Power, Heat & H2 from Biogas Success story about using waste water...

  12. Fluid flow and heat transfer modeling for castings

    SciTech Connect (OSTI)

    Domanus, H.M.; Liu, Y.Y.; Sha, W.T.

    1986-01-01T23:59:59.000Z

    Casting is fundamental to manufacturing of many types of equipment and products. Although casting is a very old technology that has been in existence for hundreds of years, it remains a highly empirical technology, and production of new castings requires an expensive and time-consuming trial-and-error approach. In recent years, mathematical modeling of casting has received increasing attention; however, a majority of the modeling work has been in the area of heat transfer and solidification. Very little work has been done in modeling fluid flow of the liquid melt. This paper presents a model of fluid flow coupled with heat transfer of a liquid melt for casting processes. The model to be described in this paper is an extension of the COMMIX code and is capable of handling castings with any shape, size, and material. A feature of this model is the ability to track the liquid/gas interface and liquid/solid interface. The flow of liquid melt through the sprue and runners and into the mold cavity is calculated as well as three-dimensional temperature and velocity distributions of the liquid melt throughout the casting process. 14 refs., 13 figs.

  13. IMPROVING THE EFFICIENCY OF THERMOELECTRIC GENERATORS BY USING SOLAR HEAT CONCENTRATORS

    E-Print Network [OSTI]

    IMPROVING THE EFFICIENCY OF THERMOELECTRIC GENERATORS BY USING SOLAR HEAT CONCENTRATORS M. T. de of thermoelectric genera- tors (TEGs) by using a lens to concentrate heat on the heat source of a TEG. Initial : Thermoelectric generator, Solar heat concentrator, Carnot efficiency I - Introduction The global energy crisis

  14. Insights into Cold Water Injection Stimulation Effects through Analytical Solutions to Flow and Heat Transport

    SciTech Connect (OSTI)

    M.A. Plummer

    2013-09-01T23:59:59.000Z

    Wells in traditional hydrothermal reservoirs are used to extract heat and to dispose of cooled water. In the first case, high productivity (the ratio of production flow rate to the pressure differential required to produce that rate) to is preferred in order to maximize power generation, while minimizing the parasitic energy loss of pumping. In the second case, high injectivity (the ratio of injection flow rate to the pressure differential required to produce that rate) is preferred, in order to reduce pumping costs. In order to improve productivity or injectivity, cold water is sometimes injected into the reservoir in an attempt to cool and contract the surrounding rock matrix and thereby induce dilation and/or extension of existing fractures or to generate new fractures. Though the increases in permeability associated with these changes are likely localized, by improving connectivity to more extensive high-permeability fractures they can at least temporarily provide substantially improved productivity or injectivity.

  15. Thermoelectric generators as self-oscillating heat engines

    E-Print Network [OSTI]

    Robert Alicki

    2015-05-30T23:59:59.000Z

    In the previous paper of Alicki et.al. a model of a solar cell has been proposed in which the non-periodic source of energy - photon flux - drives the collective periodic motion of electrons in a form of plasma oscillations. Subsequently, plasma oscillations are rectified by the p-n junction diode into the direct current (work). This approach makes a solar cell similar to standard macroscopic heat motors or turbines which always contain two heat baths, the working medium and the periodically moving piston or rotor. Here, a very similar model is proposed in order to describe the operation principles of thermoelectric generators based either on bimetallic or semiconductor p-n junctions. Again plasma oscillation corresponds to a piston and sunlight is replaced by a hot bath. The mathematical formalism is based on the Markovian master equations which can be derived in a rigorous way from the underlying Hamiltonian models and are consistent with the laws of thermodynamics.

  16. Couette flow regimes with heat transfer in rarefied gas

    SciTech Connect (OSTI)

    Abramov, A. A., E-mail: alabr54@mail.ru; Butkovskii, A. V., E-mail: albutkov@mail.ru [Zhukovski Central Aerohydrodynamics Institute (Russian Federation)

    2013-06-15T23:59:59.000Z

    Based on numerical solution of the Boltzmann equation by direct statistic simulation, the Couette flow with heat transfer is studied in a broad range of ratios of plate temperatures and Mach numbers of a moving plate. Flow regime classification by the form of the dependences of the energy flux and friction stress on the Knudsen number Kn is proposed. These dependences can be simultaneously monotonic and nonmonotonic and have maxima. Situations are possible in which the dependence of the energy flux transferred to a plate on Kn has a minimum, while the dependence of the friction stress is monotonic or even has a maximum. Also, regimes exist in which the dependence of the energy flux on Kn has a maximum, while the dependence of the friction stress is monotonic, and vice versa.

  17. Salt disposal of heat-generating nuclear waste.

    SciTech Connect (OSTI)

    Leigh, Christi D. (Sandia National Laboratories, Carlsbad, NM); Hansen, Francis D.

    2011-01-01T23:59:59.000Z

    This report summarizes the state of salt repository science, reviews many of the technical issues pertaining to disposal of heat-generating nuclear waste in salt, and proposes several avenues for future science-based activities to further the technical basis for disposal in salt. There are extensive salt formations in the forty-eight contiguous states, and many of them may be worthy of consideration for nuclear waste disposal. The United States has extensive experience in salt repository sciences, including an operating facility for disposal of transuranic wastes. The scientific background for salt disposal including laboratory and field tests at ambient and elevated temperature, principles of salt behavior, potential for fracture damage and its mitigation, seal systems, chemical conditions, advanced modeling capabilities and near-future developments, performance assessment processes, and international collaboration are all discussed. The discussion of salt disposal issues is brought current, including a summary of recent international workshops dedicated to high-level waste disposal in salt. Lessons learned from Sandia National Laboratories' experience on the Waste Isolation Pilot Plant and the Yucca Mountain Project as well as related salt experience with the Strategic Petroleum Reserve are applied in this assessment. Disposal of heat-generating nuclear waste in a suitable salt formation is attractive because the material is essentially impermeable, self-sealing, and thermally conductive. Conditions are chemically beneficial, and a significant experience base exists in understanding this environment. Within the period of institutional control, overburden pressure will seal fractures and provide a repository setting that limits radionuclide movement. A salt repository could potentially achieve total containment, with no releases to the environment in undisturbed scenarios for as long as the region is geologically stable. Much of the experience gained from United States repository development, such as seal system design, coupled process simulation, and application of performance assessment methodology, helps define a clear strategy for a heat-generating nuclear waste repository in salt.

  18. Development of Next Generation Multiphase Pipe Flow Prediction Tools

    SciTech Connect (OSTI)

    Tulsa Fluid Flow

    2008-08-31T23:59:59.000Z

    The developments of fields in deep waters (5000 ft and more) is a common occurrence. It is inevitable that production systems will operate under multiphase flow conditions (simultaneous flow of gas-oil-and water possibly along with sand, hydrates, and waxes). Multiphase flow prediction tools are essential for every phase of the hydrocarbon recovery from design to operation. The recovery from deep-waters poses special challenges and requires accurate multiphase flow predictive tools for several applications including the design and diagnostics of the production systems, separation of phases in horizontal wells, and multiphase separation (topside, seabed or bottom-hole). It is very crucial to any multiphase separation technique that is employed either at topside, seabed or bottom-hole to know inlet conditions such as the flow rates, flow patterns, and volume fractions of gas, oil and water coming into the separation devices. The overall objective was to develop a unified model for gas-oil-water three-phase flow in wells, flow lines, and pipelines to predict the flow characteristics such as flow patterns, phase distributions, and pressure gradient encountered during petroleum production at different flow conditions (pipe diameter and inclination, fluid properties and flow rates). The project was conducted in two periods. In Period 1 (four years), gas-oil-water flow in pipes were investigated to understand the fundamental physical mechanisms describing the interaction between the gas-oil-water phases under flowing conditions, and a unified model was developed utilizing a novel modeling approach. A gas-oil-water pipe flow database including field and laboratory data was formed in Period 2 (one year). The database was utilized in model performance demonstration. Period 1 primarily consisted of the development of a unified model and software to predict the gas-oil-water flow, and experimental studies of the gas-oil-water project, including flow behavior description and closure relation development for different flow conditions. Modeling studies were performed in two parts, Technology Assessment and Model Development and Enhancement. The results of the Technology assessment study indicated that the performance of the current state of the art two-phase flow models was poor especially for three-phase pipeline flow when compared with the existing data. As part of the model development and enhancement study, a new unified model for gas-oil-water three-phase pipe flow was developed. The new model is based on the dynamics of slug flow, which shares transition boundaries with all the other flow patterns. The equations of slug flow are used not only to calculate the slug characteristics, but also to predict transitions from slug flow to other flow patterns. An experimental program including three-phase gas-oil-water horizontal flow and two-phase horizontal and inclined oil-water flow testing was conducted utilizing a Tulsa University Fluid Flow Projects Three-phase Flow Facility. The experimental results were incorporated into the unified model as they became available, and model results were used to better focus and tailor the experimental study. Finally, during the Period 2, a new three-phase databank has been developed using the data generated during this project and additional data available in the literature. The unified model to predict the gas-oil-water three phase flow characteristics was tested by comparing the prediction results with the data. The results showed good agreements.

  19. Flow Boiling Heat Transfer Coefficient In Minichannels Correlation and Trends Satish G. Kandlikar

    E-Print Network [OSTI]

    Kandlikar, Satish

    Flow Boiling Heat Transfer Coefficient In Minichannels ≠ Correlation and Trends Satish G. Kandlikar York 14623, USA The flow boiling heat transfer in small diameter passages is being applied in many boiling heat transfer coefficient with the correlations developed for conventional channels. It is found

  20. Heat transfer in katabatic flow Measurements on the Morteratsch glacier, Switzerland

    E-Print Network [OSTI]

    Graaf, Martin de

    Heat transfer in katabatic flow Measurements on the Morteratsch glacier, Switzerland M. de Graaf #12;Heat transfer in katabatic flow Measurements on the Morteratsch glacier, Switzerland Martin de is used to calculate surface heat fluxes over glaciers. As determination of surface fluxes still

  1. Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law

    E-Print Network [OSTI]

    Boyer, Edmond

    Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law F transfer in a magnetic fluid flow under the action of an applied magnetic field. Instead of the usual heat-Cattaneo law, heat transfer, magnetic field, magnetization AMS subject classifications: 76N10, 35Q35. 1

  2. Numerical method for fluid flow and heat transfer in magnetohydrodynamic flow

    SciTech Connect (OSTI)

    Kim, C.N.; Abdou, M.A.

    1989-03-01T23:59:59.000Z

    A new numerical algorithm was developed to provide a fully detailed flow field in liquid metal MHD flow with a relatively large Hartmann number and interaction parameter. The algorithm includes the effects of advection and diffusion, and is capable of predicting momentum and heat transfer in MHD flows. Using this algorithm, an incompressible, viscous, three-dimensional MHD flow in a square duct is investigated at a low magnetic Reynolds number by means of the finite volume method. The velocity and temperature profiles are obtained in the developing region for constant wall temperature. The result shows that large velocities are obtained near the insulating walls parallel to the magnetic field. Also, near the perfectly conducting walls perpendicular to the field, a velocity profile like a Hartmann layer is obtained. In association with the velocity profiles, Nusselt number at the insulating walls (with side layer) is seen to be larger than that at the perfectly conducting walls (with Hartmann layer).

  3. NUMERICAL ANALYSIS OF VAPOR BUBBLE GROWTH AND WALL HEAT TRANSFER DURING FLOW BOILING OF WATER IN A MICROCHANNEL

    E-Print Network [OSTI]

    Kandlikar, Satish

    . (2004) developed three- zone flow boiling heat transfer model to describe evaporation of elongated

  4. Macroscopic implications from phase space dynamics of tokamak turbulence : relaxation, transport, and flow generation

    E-Print Network [OSTI]

    Kosuga, Yusuke

    2012-01-01T23:59:59.000Z

    entropy production via heat input. Comparison of the resultsis ultimately set by heat input, it seems that we can viewconverted flow. In Venus, heat input from the Sun drives

  5. Experimental validation of large eddy simulations of flow and heat transfer in a stationary ribbed duct

    E-Print Network [OSTI]

    Thole, Karen A.

    Elsevier Inc. All rights reserved. Keywords: Duct flow; Ribbed channels; LES 1. Introduction In an effortExperimental validation of large eddy simulations of flow and heat transfer in a stationary ribbed Abstract Accurate prediction of ribbed duct flow and heat transfer is of importance to the gas turbine

  6. Development of Next Generation Multiphase Pipe Flow Prediction Tools

    SciTech Connect (OSTI)

    Cem Sarica; Holden Zhang

    2006-05-31T23:59:59.000Z

    The developments of oil and gas fields in deep waters (5000 ft and more) will become more common in the future. It is inevitable that production systems will operate under multiphase flow conditions (simultaneous flow of gas, oil and water possibly along with sand, hydrates, and waxes). Multiphase flow prediction tools are essential for every phase of hydrocarbon recovery from design to operation. Recovery from deep-waters poses special challenges and requires accurate multiphase flow predictive tools for several applications, including the design and diagnostics of the production systems, separation of phases in horizontal wells, and multiphase separation (topside, seabed or bottom-hole). It is crucial for any multiphase separation technique, either at topside, seabed or bottom-hole, to know inlet conditions such as flow rates, flow patterns, and volume fractions of gas, oil and water coming into the separation devices. Therefore, the development of a new generation of multiphase flow predictive tools is needed. The overall objective of the proposed study is to develop a unified model for gas-oil-water three-phase flow in wells, flow lines, and pipelines to predict flow characteristics such as flow patterns, phase distributions, and pressure gradient encountered during petroleum production at different flow conditions (pipe diameter and inclination, fluid properties and flow rates). In the current multiphase modeling approach, flow pattern and flow behavior (pressure gradient and phase fractions) prediction modeling are separated. Thus, different models based on different physics are employed, causing inaccuracies and discontinuities. Moreover, oil and water are treated as a pseudo single phase, ignoring the distinct characteristics of both oil and water, and often resulting in inaccurate design that leads to operational problems. In this study, a new model is being developed through a theoretical and experimental study employing a revolutionary approach. The basic continuity and momentum equations is established for each phase, and used for both flow pattern and flow behavior predictions. The required closure relationships are being developed, and will be verified with experimental results. Gas-oil-water experimental studies are currently underway for the horizontal pipes. Industry-driven consortia provide a cost-efficient vehicle for developing, transferring, and deploying new technologies into the private sector. The Tulsa University Fluid Flow Projects (TUFFP) is one of the earliest cooperative industry-university research consortia. TUFFP's mission is to conduct basic and applied multiphase flow research addressing the current and future needs of hydrocarbon production and transportation. TUFFP participants and The University of Tulsa are supporting this study through 55% cost sharing.

  7. Thermophoretic transport of particles that act as volumetric heat sources in natural convection flow

    SciTech Connect (OSTI)

    Conklin, J.C.; Krane, R.J. (Oak Ridge National Lab., TN (USA); Tennessee Univ., Knoxville, TN (USA). Dept. of Mechanical and Aerospace Engineering)

    1989-01-01T23:59:59.000Z

    The natural convection boundary layer with suspended heat generating aerosol particles adjacent to a cooled, isothermal, vertical wall was investigated for the following circumstances: laminar and turbulent flow, large temperature differences between the wall and the fluid, stable thermal stratification far from the wall, and fluid participation in thermal radiation heat transfer. The deposition of aerosol particles by thermophoresis was investigated. A scaling analysis showed the negligible effect inside the boundary layer of the particulate heat source strengths of practical interest. Only the temperature of the fluid far from the wall is affected appreciably by the heat sources. The scaled boundary layer differential equations are transformed to a nonsimilarity form for numerical solution using two different methods. An expression for the ratio of mass transfer to heat transfer coefficients was developed to simplify the computation of thermophoretic particle deposition at the wall for the case of constant temperature conditions far from the wall. Variable thermophysical property effect for the three gases of steam, air, and hydrogen were investigated. A dimensionless ratio of transfer coefficients for large temperature differences and turbulent flow was computed as a product of the laminar constant property results and a ratio of the known thermophysical properties at the wall and far from the wall. An approximation of the laminar constant property results for all three gases is developed in terms of the known wall and fluid temperatures, Prandtl number, and a thermophoretic constant. This allows particle deposition to be computed from a known heat transfer coefficient without explicitly solving the particle conservation equation. 120 refs., 29 figs., 21 tabs.

  8. FLOW AND HEAT TRANSFER IN MICROFLUIDIC DEVICES WITH APPLICATION TO OPTOTHERMAL

    E-Print Network [OSTI]

    Bahrami, Majid

    FLOW AND HEAT TRANSFER IN MICROFLUIDIC DEVICES WITH APPLICATION TO OPTOTHERMAL ANALYTE transfer in microfluidic devices with applica- tion to optothermal analyte preconcentration and manipula the local fluid temperature in microfluidics. Thermal characteristics of the heating system have been

  9. Simulation of Strongly Heated Internal Gas Flows Using a Near-Wall Two-Equation Heat Flux Model

    SciTech Connect (OSTI)

    Richards, Adam H.; Spall, Robert E. [Utah State University, 1400 Old Main Hill Logan, Utah 84322-1400 (United States)

    2006-07-01T23:59:59.000Z

    A two-equation k-{omega} model is used to model a strongly heated, low-Mach number gas flowing upward in a vertical tube. Heating causes significant property variation and thickening of the viscous sublayer, consequently a fully developed flow does not evolve. Two-equation turbulence models generally perform poorly under such conditions. Consequently, in the present work, a near-wall two-equation heat transfer model is utilized in conjunction with the k-{omega} model to improve heat transfer predictions. (authors)

  10. A Variable Refrigerant Flow Heat Pump Computer Model in EnergyPlus

    SciTech Connect (OSTI)

    Raustad, Richard A. [Florida Solar Energy Center

    2013-01-01T23:59:59.000Z

    This paper provides an overview of the variable refrigerant flow heat pump computer model included with the Department of Energy's EnergyPlusTM whole-building energy simulation software. The mathematical model for a variable refrigerant flow heat pump operating in cooling or heating mode, and a detailed model for the variable refrigerant flow direct-expansion (DX) cooling coil are described in detail.

  11. Efficiency and Air Quality Implications of Distributed Generation and Combined Heat

    E-Print Network [OSTI]

    Efficiency and Air Quality Implications of Distributed Generation and Combined Heat and Power potentially increase exposure to air pollutants. When distributed generation is efficiently deployed to determine accurately the efficiencies and emissions of various applications of distributed generation

  12. A Site-Scale Model For Fluid And Heat Flow In The Unsaturated...

    Open Energy Info (EERE)

    heat at Yucca Mountain, Nevada, a potential repository site for high-level radioactive waste. The model takes into account the simultaneous flow dynamics of liquid water, vapor,...

  13. Effect of nonuniform inlet air flow on air-cooled heat-exchanger performance

    SciTech Connect (OSTI)

    Soler, A.I.; Singh, K.P.; Ng, T.L.

    1983-01-01T23:59:59.000Z

    Blowers used to propel air across tube bundles generate a non-uniform flow field due to their construction details. A formalism to evaluate heat transfer degradation due to non-uniform airflow has been developed. Certain symmetry relations for cross flowheat exchangers, heretofore unavailable in the open literature, have been derived. The solution presented here was developed to model a 4 tube pass air blast heat exchanger for the Clinch River Breeder Reactor Plant Project. This case is utilized to show how this method can be used as a design tool to select the most suitable blower construction for a particular application. A numerical example is used to illustrate the salient points of the solution.

  14. Intercalation-Induced Stress and Heat Generation within Single Lithium-Ion Battery Cathode Particles

    E-Print Network [OSTI]

    Sastry, Ann Marie

    Intercalation-Induced Stress and Heat Generation within Single Lithium-Ion Battery Cathode, as will be discussed later. Heat transfer analyses of lithium-ion batteries have stemmed from work on full cells.10-induced stress and heat generation inside Li-ion battery cathode LiMn2O4 particles under potentiodynamic control

  15. Heat generation from electronics increases with the advent of high-density integrated circuit technology. To

    E-Print Network [OSTI]

    Boyer, Edmond

    circuit technology. To come up with the heat generation, microscale cooling has been thought as a promising technology. Prediction of heat transfer rate is crucial in design of microscale cooling device1 Abstract Heat generation from electronics increases with the advent of high-density integrated

  16. Photometric studies of heat flow at the photosphere

    SciTech Connect (OSTI)

    Foukal, P.

    1984-05-01T23:59:59.000Z

    Continuum photometry is carried out and the results of comparing these observations with models of photospheric heat flow are described. The main results are: (1) a possible detection of weak bright rings around some spot penumbrae (2) no evidence is found for large scale photospheric brightness inhomogeneities exceeding 2-3 K which places tighter constraints on models of global scale convection (3) supergranular scale continuum structures observed across the photosphere appear mainly due to random clumping of granules (4) the one case observed of a sunspot emergence shows no thermal shadow exceeding 1.5 K rms one day prior to umbra appearance (5) network and faculae are found to show a small excess brightness even at mu 1, so detection of faculae at mu 1 by differential photometry indicates a gentler temperature gradient near tau 1 in the facular (relative to cell) atmosphere (6) the limb darkening study shows no significant global variations to within 0.1% rms.

  17. 1.12.2014bo Akademi Univ -Thermal and Flow Engineering Piispankatu 8, 20500 Turku 1/24 8. Heat pumps, heat pipes,

    E-Print Network [OSTI]

    Zevenhoven, Ron

    of low-temperature (waste) heat, replacing sources of (unnecessarily) high temperature heat (and, 3) outside water heat and 4) heat from another indoor space, or 5) waste heat from a process1.12.2014Ňbo Akademi Univ - Thermal and Flow Engineering Piispankatu 8, 20500 Turku 1/24 8. Heat

  18. Generation of mirage effect by heated carbon nanotube thin film

    SciTech Connect (OSTI)

    Tong, L. H. [Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230026 (China); USTC-CityU Joint Advanced Research Centre, Suzhou, Jiangsu 215123 (China); Lim, C. W., E-mail: bccwlim@cityu.edu.hk [USTC-CityU Joint Advanced Research Centre, Suzhou, Jiangsu 215123 (China); Department of Civil and Architectural Engineering, City University of Hong Kong, Kowloon, Hong Kong, Peopleís Republic of China and City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057 (China); Li, Y. C. [Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zhang, Chuanzeng; Quoc Bui, Tinh [Department of Civil Engineering, University of Siegen, Paul-Bonatz-Str. 9-11, D-57076 Siegen (Germany)

    2014-06-28T23:59:59.000Z

    Mirage effect, a common phenomenon in nature, is a naturally occurring optical phenomenon in which lights are bent due to the gradient variation of refraction in the temperature gradient medium. The theoretical analysis of mirage effect generated by heated carbon nanotube thin film is presented both for gas and liquid. Excellent agreement is demonstrated through comparing the theoretical prediction with published experimental results. It is concluded from the theoretical prediction and experimental observation that the mirage effect is more likely to happen in liquid. The phase of deflected optical beam is also discussed and the method for measurement of thermal diffusivity of medium is theoretically verified. Furthermore, a method for measuring the refractive index of gas by detecting optical beam deflection is also presented in this paper.

  19. Some aspects of materials development for sodium heated steam generators

    SciTech Connect (OSTI)

    Roy, P.; Spalaris, C.N.

    1980-10-01T23:59:59.000Z

    A development program was undertaken to support the materials selection for steam generator piping and IHX which are to be used in Liquid Metal Fast Breeder Reactors (LMFBR). Four major topics were reviewed, describing the results obtained as well as the direction of future tests. These topics are: carbon transport in sodium, effect of carbon loss/gain upon materials in the reactor Intermediate Heat Transport System (IHTS), corrosion fatigue and aqueous corrosion. The results support the initial assumptions made in specifying the use of 2-1/4Cr-1Mo as the construction material for the evaporator and superheater and Type 316 piping of the IHT system. Future direction of the experimental programs is to further verify the materials choice and to also obtain information which will be essential during the plant installation, operation and reliability of the components.

  20. 2.13 HEAT TRANSFER & FLUID FLOW IN MICROCHANNELS 2.13.7-1 Molecular dynamics methods in

    E-Print Network [OSTI]

    Maruyama, Shigeo

    2.13 HEAT TRANSFER & FLUID FLOW IN MICROCHANNELS 2.13.7-1 2.13.7 Molecular dynamics methods in microscale heat transfer Shigeo Maruyama A. Introduction In normal heat transfer and fluid flow calculations of molecules. This situation is approached in microscale heat transfer and fluid flow. Molecular level

  1. Heat exchanger design for thermoelectric electricity generation from low temperature flue gas streams

    E-Print Network [OSTI]

    Latcham, Jacob G. (Jacob Greco)

    2009-01-01T23:59:59.000Z

    An air-to-oil heat exchanger was modeled and optimized for use in a system utilizing a thermoelectric generator to convert low grade waste heat in flue gas streams to electricity. The NTU-effectiveness method, exergy, and ...

  2. CHARACTERIZATION OF ELEVATED TEMPERATURE PROPERTIES OF HEAT EXCHANGER AND STEAM GENERATOR ALLOYS

    SciTech Connect (OSTI)

    J.K. Wright; L.J. Carroll; C.J. Cabet; T. Lillo; J.K. Benz; J.A. Simpson; A. Chapman; R.N. Wright

    2012-10-01T23:59:59.000Z

    The Next Generation Nuclear Plant project is considering Alloy 800H and Alloy 617 for steam generator and intermediate heat exchangers. It is envisioned that a steam generator would operate with reactor outlet temperatures from 750 to 800 C, while an intermediate heat exchanger for primary to secondary helium would operate up to an outlet temperature of 950 C. Although both alloys are of interest due in part to their technical maturity, a number of specific properties require further characterization for design of nuclear components. Strain rate sensitivity of both alloys has been characterized and is found to be significant above 600 C. Both alloys also exhibit dynamic strain aging, characterized by serrated flow, over a wide range of temperatures and strain rates. High temperature tensile testing of Alloy 617 has been conducted over a range of temperatures. Dynamic strain aging is a concern for these materials since it is observed to result in reduced ductility for many solid solution alloys. Creep, fatigue, and creep-fatigue properties of Alloy 617 have been measured as well, with the goal of determining the influence of the temperature, strain rate and atmosphere on the creep fatigue life of Alloy 617. Elevated temperature properties and implications for codification of the alloys will be described.

  3. MINET: transient analysis of fluid-flow and heat-transfer networks

    SciTech Connect (OSTI)

    Van Tuyle, G.J.; Guppy, J.G.; Nepsee, T.C.

    1983-01-01T23:59:59.000Z

    MINET, a computer code developed for the steady-state and transient analysis of fluid-flow and heat-transfer networks, is described. The code is based on a momentum integral network method, which offers significant computational advantages in the analysis of large systems, such as the balance of plant in a power-generating facility. An application is discussed in which MINET is coupled to the Super System Code (SSC), an advanced generic code for the transient analysis of loop- or pool-type LMFBR systems. In this application, the ability of the Clinch River Breeder Reactor Plant to operate in a natural circulation mode following an assumed loss of all electric power, was assessed. Results from the MINET portion of the calculations are compared against those generated independently by the Clinch River Project, using the DEMO code.

  4. Friction and Heat Transfer Characteristics of Silica and CNT Nanofluids in a Tube Flow

    E-Print Network [OSTI]

    Kostic, Milivoje M.

    Friction and Heat Transfer Characteristics of Silica and CNT Nanofluids in a Tube Flow MILIVOJE M of nanofluids in tube flow has been developed, instrumented and computerized. It has been calibrated using) nanofluids show peculiar results with substantial friction drag reduction and heat transfer enhancement

  5. Large deviations in stochastic heat-conduction processes provide a gradient-flow structure for heat conduction

    SciTech Connect (OSTI)

    Peletier, Mark A., E-mail: m.a.peletier@tue.nl [Department of Mathematics and Computer Science and Institute for Complex Molecular Systems, Technische Universiteit Eindhoven, Postbus 513, 5600 MB Eindhoven (Netherlands); Redig, Frank, E-mail: f.h.j.redig@tudelft.nl [Delft Institute of Applied Mathematics, Technische Universiteit Delft, Mekelweg 4, 2628 CD Delft (Netherlands); Vafayi, Kiamars, E-mail: k.vafayi@tue.nl [Department of Mathematics and Computer Science, Technische Universiteit Eindhoven, Postbus 513, 5600 MB Eindhoven (Netherlands)

    2014-09-01T23:59:59.000Z

    We consider three one-dimensional continuous-time Markov processes on a lattice, each of which models the conduction of heat: the family of Brownian Energy Processes with parameter m (BEP(m)), a Generalized Brownian Energy Process, and the Kipnis-Marchioro-Presutti (KMP) process. The hydrodynamic limit of each of these three processes is a parabolic equation, the linear heat equation in the case of the BEP(m) and the KMP, and a nonlinear heat equation for the Generalized Brownian Energy Process with parameter a (GBEP(a)). We prove the hydrodynamic limit rigorously for the BEP(m), and give a formal derivation for the GBEP(a). We then formally derive the pathwise large-deviation rate functional for the empirical measure of the three processes. These rate functionals imply gradient-flow structures for the limiting linear and nonlinear heat equations. We contrast these gradient-flow structures with those for processes describing the diffusion of mass, most importantly the class of Wasserstein gradient-flow systems. The linear and nonlinear heat-equation gradient-flow structures are each driven by entropy terms of the form -log ?; they involve dissipation or mobility terms of order ?≤ for the linear heat equation, and a nonlinear function of ? for the nonlinear heat equation.

  6. Flow-Induced Deformation of a Flexible Thin Structure as Manifestation of Heat Transfer Enhancement

    E-Print Network [OSTI]

    Soti, Atul Kumar; Sheridan, John

    2015-01-01T23:59:59.000Z

    Flow-induced deformation of thin structures coupled with convective heat transfer has potential applications in energy harvesting and is important for understanding functioning of several biological systems. We numerically demonstrate large-scale flow-induced deformation as an effective passive heat transfer enhancement technique. An in-house, strongly-coupled fluid-structure interaction (FSI) solver is employed in which flow and structure solvers are based on sharp-interface immersed boundary and finite element method, respectively. In the present work, we validate convective heat transfer module of the in-house FSI solver against several benchmark examples of conduction and convective heat transfer including moving structure boundaries. The thermal augmentation is investigated as well as quantified for the flow-induced deformation of an elastic thin plate attached to lee side of a rigid cylinder in a heated channel laminar flow. We show that the wake vortices past the plate sweep higher sources of vorticity...

  7. Vector Field Smoothing Via Heat Flow Antonio Robles-Kelly and Edwin R. Hancock

    E-Print Network [OSTI]

    Robles-Kelly, Antonio

    Vector Field Smoothing Via Heat Flow Antonio Robles-Kelly and Edwin R. Hancock Department into that of solving the steady state heat equation for a scalar potential. According to this picture, the smoothed field of surface nor- mals is found by taking the gradient of the scalar field. The heat equation

  8. Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow

    E-Print Network [OSTI]

    Boyer, Edmond

    Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S in a rotor-stator cavity subjected to a superimposed throughflow with heat transfer. Nu- merical predictions field from the heat transfer process. The turbulent flux is approximated by a gradient hypothesis

  9. Heat transfer and friction characteristics of air flow in microtubes Chien-Yuh Yang a,

    E-Print Network [OSTI]

    Kandlikar, Satish

    Heat transfer and friction characteristics of air flow in microtubes Chien-Yuh Yang a, , Chia September 2011 Keywords: Microtube Heat transfer Liquid Crystal Thermography a b s t r a c t Several researches dealing with the single-phase forced convection heat transfer inside microchannels have been

  10. Investigation of flow maldistribution in a concentric-tube, counterflow, laminar heat exchanger

    SciTech Connect (OSTI)

    Ratts, E.B. [Univ. of Michigan, Dearborn, MI (United States). Dept. of Mechanical Engineering

    1998-07-01T23:59:59.000Z

    An analysis is made to quantify the effect of flow maldistribution on the performance of a laminar, counterflow, high-effectiveness heat exchanger. An investigation of the ability of thermally connected fins in one passage (screen mesh) to correct the uneven heat transfer distribution from the maldistributed mass flow in the other passage is made. A heat transfer model is developed for both passages. A parametric study presents the effect of adding thermal paths to correct the uneven heat transfer. A redefined fin efficiency is proposed to incorporate the fins` ability to correct uneven heat transfer. Data are compared to the model.

  11. Potential vertical movement of large heat-generating waste packages in salt.

    SciTech Connect (OSTI)

    Clayton, Daniel James; Martinez, Mario J.; Hardin, Ernest L.

    2013-05-01T23:59:59.000Z

    With renewed interest in disposal of heat-generating waste in bedded or domal salt formations, scoping analyses were conducted to estimate rates of waste package vertical movement. Vertical movement is found to result from thermal expansion, from upward creep or heave of the near-field salt, and from downward buoyant forces on the waste package. A two-pronged analysis approach was used, with thermal-mechanical creep modeling, and coupled thermal-viscous flow modeling. The thermal-mechanical approach used well-studied salt constitutive models, while the thermal-viscous approach represented the salt as a highly viscous fluid. The Sierra suite of coupled simulation codes was used for both approaches. The waste package in all simulations was a right-circular cylinder with the density of steel, in horizontal orientation. A time-decaying heat generation function was used to represent commercial spent fuel with typical burnup and 50-year age. Results from the thermal-mechanical base case showed approximately 27 cm initial uplift of the package, followed by gradual relaxation closely following the calculated temperature history. A similar displacement history was obtained with the package density set equal to that of salt. The slight difference in these runs is attributable to buoyant displacement (sinking) and is on the order of 1 mm in 2,000 years. Without heat generation the displacement stabilizes at a fraction of millimeter after a few hundred years. Results from thermal-viscous model were similar, except that the rate of sinking was constant after cooldown, at approximately 0.15 mm per 1,000 yr. In summary, all calculations showed vertical movement on the order of 1 mm or less in 2,000 yr, including calculations using well-established constitutive models for temperature-dependent salt deformation. Based on this finding, displacement of waste packages in a salt repository is not a significant repository performance issue.

  12. Nonlinear power flow control applications to conventional generator swing equations subject to variable generation.

    SciTech Connect (OSTI)

    Robinett, Rush D., III; Wilson, David Gerald

    2010-05-01T23:59:59.000Z

    In this paper, the swing equations for renewable generators are formulated as a natural Hamiltonian system with externally applied non-conservative forces. A two-step process referred to as Hamiltonian Surface Shaping and Power Flow Control (HSSPFC) is used to analyze and design feedback controllers for the renewable generator system. This formulation extends previous results on the analytical verification of the Potential Energy Boundary Surface (PEBS) method to nonlinear control analysis and design and justifies the decomposition of the system into conservative and non-conservative systems to enable a two-step, serial analysis and design procedure. In particular, this approach extends the work done by developing a formulation which applies to a larger set of Hamiltonian Systems that has Nearly Hamiltonian Systems as a subset. The results of this research include the determination of the required performance of a proposed Flexible AC Transmission System (FACTS)/storage device to enable the maximum power output of a wind turbine while meeting the power system constraints on frequency and phase. The FACTS/storage device is required to operate as both a generator and load (energy storage) on the power system in this design. The Second Law of Thermodynamics is applied to the power flow equations to determine the stability boundaries (limit cycles) of the renewable generator system and enable design of feedback controllers that meet stability requirements while maximizing the power generation and flow to the load. Necessary and sufficient conditions for stability of renewable generators systems are determined based on the concepts of Hamiltonian systems, power flow, exergy (the maximum work that can be extracted from an energy flow) rate, and entropy rate.

  13. Heat transport and weakening of atmospheric stability induced by mesoscale flows

    E-Print Network [OSTI]

    Pielke, Roger A.

    Heat transport and weakening of atmospheric stability induced by mesoscale flows G. A. Dalu boundary layer (CBL) is transported upward into the midtroposphere by mesoscale flows, and how the air, and diffusion, associated with the mesoscale flow, is more clearly shown when the forcing is periodic in time

  14. Cytoskeletal stability and heat shock-mediated thermoprotection of central pattern generation in Locusta migratoria

    E-Print Network [OSTI]

    Robertson, Meldrum

    Cytoskeletal stability and heat shock-mediated thermoprotection of central pattern generation heat shock is not fully understood, and our goal was to test the idea that cytoskeletal stability) were bath-applied in semi-intact locust preparations in both control (C) and pre-treated heat

  15. Electricity-producing heating apparatus utilizing a turbine generator in a semi-closed brayton cycle

    DOE Patents [OSTI]

    Labinov, Solomon D.; Christian, Jeffrey E.

    2003-10-07T23:59:59.000Z

    The present invention provides apparatus and methods for producing both heat and electrical energy by burning fuels in a stove or boiler using a novel arrangement of a surface heat exchanger and microturbine-powered generator and novel surface heat exchanger. The equipment is particularly suited for use in rural and relatively undeveloped areas, especially in cold regions and highlands.

  16. Generator-Absorber heat exchange transfer apparatus and method using an intermediate liquor

    DOE Patents [OSTI]

    Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)

    1996-11-05T23:59:59.000Z

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium where the working solution has an intermediate liquor concentration.

  17. Scale/Analytical Analyses of Freezing and Convective Melting with Internal Heat Generation

    SciTech Connect (OSTI)

    Ali S. Siahpush; John Crepeau; Piyush Sabharwall

    2013-07-01T23:59:59.000Z

    Using a scale/analytical analysis approach, we model phase change (melting) for pure materials which generate constant internal heat generation for small Stefan numbers (approximately one). The analysis considers conduction in the solid phase and natural convection, driven by internal heat generation, in the liquid regime. The model is applied for a constant surface temperature boundary condition where the melting temperature is greater than the surface temperature in a cylindrical geometry. The analysis also consider constant heat flux (in a cylindrical geometry).We show the time scales in which conduction and convection heat transfer dominate.

  18. Air flow in a high aspect ratio heat sink

    E-Print Network [OSTI]

    Allison, Jonathan Michael

    2010-01-01T23:59:59.000Z

    The increasing heat output of modern electronics requires concomitant advances in heat sinking technology: reductions in thermal resistance and required pumping power are necessary. This research covers the development of ...

  19. Scaling laws for heat generation and temperature oscillations in EDLCs under galvanostatic cycling

    E-Print Network [OSTI]

    Pilon, Laurent

    Scaling laws for heat generation and temperature oscillations in EDLCs under galvanostatic cycling rules and thermal management strategies for electric double layer capacitors (EDLCs). First, it presents heat generated during a charging step and for the maximum temperature oscillations in EDLCs under

  20. Improved method for calculating the radiation heat generation in the BOR-60 reactor

    SciTech Connect (OSTI)

    Varivtsev, A. V., E-mail: vav3@niiar.ru; Zhemkov, I. Yu. [JSC ďSSC RIAR,Ē Dimitrovgrad-10 (Russian Federation)

    2014-12-15T23:59:59.000Z

    The results of theoretical and experimental studies aimed at determining the radiation heat generation in the BOR-60 reactor reveal the drawbacks of the computational methods used at present. An algorithm that is free from these drawbacks and allows one to determine the radiation heat generation computationally is proposed.

  1. Dependable Hydrogen and Industrial Heat Generation from the Next Generation Nuclear Plant

    SciTech Connect (OSTI)

    Charles V. Park; Michael W. Patterson; Vincent C. Maio; Piyush Sabharwall

    2009-03-01T23:59:59.000Z

    The Department of Energy is working with industry to develop a next generation, high-temperature gas-cooled nuclear reactor (HTGR) as a part of the effort to supply the US with abundant, clean and secure energy. The Next Generation Nuclear Plant (NGNP) project, led by the Idaho National Laboratory, will demonstrate the ability of the HTGR to generate hydrogen, electricity, and high-quality process heat for a wide range of industrial applications. Substituting HTGR power for traditional fossil fuel resources reduces the cost and supply vulnerability of natural gas and oil, and reduces or eliminates greenhouse gas emissions. As authorized by the Energy Policy Act of 2005, industry leaders are developing designs for the construction of a commercial prototype producing up to 600 MWt of power by 2021. This paper describes a variety of critical applications that are appropriate for the HTGR with an emphasis placed on applications requiring a clean and reliable source of hydrogen. An overview of the NGNP project status and its significant technology development efforts are also presented.

  2. Original article Influence of heating conditions in continuous-flow

    E-Print Network [OSTI]

    Paris-Sud XI, Universitť de

    , holding and cooling phases. When milk was heated in a continuous microwave heating system, at 90 įC and cooling times. vitamin B1 / vitamin B2 / milk / microwave heating Rťsumť -- …tude de l'effet des exchange systems on the vitamin B1 and B2 content of milk Isabel SIERRA, Concepciůn VIDAL

  3. OSCILLATORY FLOW FORCED CONVECTION IN MICRO HEAT SPREADERS

    E-Print Network [OSTI]

    Beskok, Ali

    transfer devices, micro heat pipes, based on capillary pumping of a multiphase Įuid in microchannels, have-phase forced convection heat transfer and Įow characteristics of water in microchannels, both in the laminar) concept for ef cient transport of large, concentrated heat loads is introduced. The MHS is a single

  4. INTERNAL FORCED iquid or gas flow through pipes or ducts is commonly used in heating and

    E-Print Network [OSTI]

    Ghajar, Afshin J.

    to flow by a fan or pump through a flow section that is sufficiently long to accomplish the desired heat. Then the logarithmic mean temperature difference and the rate of heat loss from the air become Tln 15.2¬įC Q ¬∑ hAs Tln (13.5 W/m2 ¬įC)(6.4 m2 )( 15.2¬įC) 1313 W Therefore, air will lose heat at a rate of 1313 W as it flows

  5. District heating from electric-generating plants and municipal incinerators: local planner's assessment guide

    SciTech Connect (OSTI)

    Pferdehirt, W.; Kron, N. Jr.

    1980-11-01T23:59:59.000Z

    This guide is designed to aid local government planners in the preliminary evaluation of the feasibility of district heating using heat recovered from electric generating plants and municipal incinerators. System feasibility is indicated by: (1) the existence of an adequate supply of nearby waste heat, (2) the presence of a sufficiently dense and large thermal load, and (3) a favorable cost comparison with conventional heating methods. 34 references.

  6. Heat Transfer Research 44(1), 130 (2013) ENTROPY GENERATION ANALYSIS

    E-Print Network [OSTI]

    Zhang, Yuwen

    Heat Transfer Research 44(1), 1­30 (2013) ENTROPY GENERATION ANALYSIS FOR A PULSATING HEAT, m R gas constant of vapor, g gravity, m/s2 kJ/kgK h(hlsen, hlv) coefficient of convective heat Re, kg/m3 of left vapor plug, W p shear stress, N/m3 Qout,v1 condensation heat transfer rate Subscripts

  7. Steam generators two phase flows numerical simulation with liquid and gas momentum equations

    E-Print Network [OSTI]

    Paris-Sud XI, Universitť de

    . The secondary flow is another loop that links the steam generator and the turbines. Inside the exchangerSteam generators two phase flows numerical simulation with liquid and gas momentum equations M Abstract This work takes place in steam generators flow studies and we consider here steady state three

  8. Bypass valve and coolant flow controls for optimum temperatures in waste heat recovery systems

    DOE Patents [OSTI]

    Meisner, Gregory P

    2013-10-08T23:59:59.000Z

    Implementing an optimized waste heat recovery system includes calculating a temperature and a rate of change in temperature of a heat exchanger of a waste heat recovery system, and predicting a temperature and a rate of change in temperature of a material flowing through a channel of the waste heat recovery system. Upon determining the rate of change in the temperature of the material is predicted to be higher than the rate of change in the temperature of the heat exchanger, the optimized waste heat recovery system calculates a valve position and timing for the channel that is configurable for achieving a rate of material flow that is determined to produce and maintain a defined threshold temperature of the heat exchanger, and actuates the valve according to the calculated valve position and calculated timing.

  9. Why Blow Away Heat? Harvest Server's Heat Using Ther-moelectric Generators

    E-Print Network [OSTI]

    Huang, Polly

    ABSTRACT This paper argues for harvesting energy from servers' wasted heat in data centers. Our approach. INTRODUCTION A data center consumes vast amount of electricity and produces enormous amount of wasted heat that needs to be removed by cooling facilities. This paper looks at wasted heat as opportunities for energy

  10. Study of Laminar Flow Forced Convection Heat Transfer Behavior of a Phase Change Material Fluid

    E-Print Network [OSTI]

    Ravi, Gurunarayana

    2010-01-14T23:59:59.000Z

    with constant peripheral temperature and uniform axial and peripheral temperature, were considered in the case of circular tubes. An effective specific heat technique was used to model the phase change process assuming a hydrodynamically fully-developed flow...

  11. An experimental investigation of critical heat flux in subcooled internal flow

    E-Print Network [OSTI]

    Shatto, Donald Patrick

    1997-01-01T23:59:59.000Z

    diameters, tube lengths, and mass flow rates. Methods of developing predictive correlations for subcooled critical heat flux based on dimensional analysis, and the sublayer dryout model, are described and applied to the data from these experiments. When...

  12. Visualization of flow boiling in an annular heat exchanger under reduced gravity conditions

    E-Print Network [OSTI]

    Westheimer, David Thomas

    2000-01-01T23:59:59.000Z

    This work examines the effects of gravitational acceleration on the flow boiling process. A test facility focusing on an annular heat exchanger was designed, built out of borosilicate glass, and flown on NASA's KC-135 reduced gravity airplane...

  13. Heat Flow of Biharmonic Maps in Dimensions Four and Its Application

    E-Print Network [OSTI]

    2007-06-07T23:59:59.000Z

    the heat flow of extrinsic biharmonic maps from M to N, which is smooth away from finitely ..... Now we need to have the uniform control of. ?. M. |ut|2. For this†...

  14. Heat Flow From Four New Research Drill Holes In The Western Cascades...

    Open Energy Info (EERE)

    New Research Drill Holes In The Western Cascades, Oregon, Usa Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Heat Flow From Four New Research...

  15. Film boiling of saturated liquid flowing upward through a heated tube : high vapor quality range

    E-Print Network [OSTI]

    Laverty, W. F.

    1964-01-01T23:59:59.000Z

    Film boiling of saturated liquid flowing upward through a uniformly heated tube has been studied for the case in which pure saturated liquid enters the tube and nearly saturated vapor is discharged. Since a previous study ...

  16. Geothermal Resource-Reservoir Investigations Based On Heat Flow...

    Open Energy Info (EERE)

    numerical models are used to establish basic qualitative relationships between structure, heat input, and permeability distribution, and the resulting geothermal system. A series...

  17. Heat transfer and pressure drop for air flow through enhanced passages

    SciTech Connect (OSTI)

    Obot, N.T.; Esen, E.B.

    1992-06-01T23:59:59.000Z

    An extensive experimental investigation was carried out to determine the pressure drop and heat transfer characteristics for laminar, transitional and turbulent flow of air through a smooth passage and twenty-three enhanced passages. The internal surfaces of all enhanced passages had spirally shaped geometries; these included fluted, finned/ribbed and indented surfaces. The Reynolds number (Re) was varied between 400 and 50000. The effect of heat transfer (wall cooling or fluid heating) on pressure drop is most significant within the transition region; the recorded pressure drop with heat transfer is much higher than that without heat transfer. The magnitude of this effect depends markedly on the average surface temperature and, to a lesser extent, on the geometric characteristics of the enhanced surfaces. When the pressure drop data are reduced as values of the Fanning friction factor(f), the results are about the same with and without heat transfer for turbulent flow, with moderate differences in the laminar and transition regions.

  18. Heat transfer and pressure drop for air flow through enhanced passages. Final report

    SciTech Connect (OSTI)

    Obot, N.T.; Esen, E.B.

    1992-06-01T23:59:59.000Z

    An extensive experimental investigation was carried out to determine the pressure drop and heat transfer characteristics for laminar, transitional and turbulent flow of air through a smooth passage and twenty-three enhanced passages. The internal surfaces of all enhanced passages had spirally shaped geometries; these included fluted, finned/ribbed and indented surfaces. The Reynolds number (Re) was varied between 400 and 50000. The effect of heat transfer (wall cooling or fluid heating) on pressure drop is most significant within the transition region; the recorded pressure drop with heat transfer is much higher than that without heat transfer. The magnitude of this effect depends markedly on the average surface temperature and, to a lesser extent, on the geometric characteristics of the enhanced surfaces. When the pressure drop data are reduced as values of the Fanning friction factor(f), the results are about the same with and without heat transfer for turbulent flow, with moderate differences in the laminar and transition regions.

  19. Enhanced Heat Flow in the Hydrodynamic Collisionless Regime

    SciTech Connect (OSTI)

    Meppelink, R.; Rooij, R. van; Vogels, J. M.; Straten, P. van der [Atom Optics and Ultrafast Dynamics, Utrecht University, P.O. Box 80000, 3508 TA Utrecht (Netherlands)

    2009-08-28T23:59:59.000Z

    We study the heat conduction of a cold, thermal cloud in a highly asymmetric trap. The cloud is axially hydrodynamic, but due to the asymmetric trap radially collisionless. By locally heating the cloud we excite a thermal dipole mode and measure its oscillation frequency and damping rate. We find an unexpectedly large heat conduction compared to the homogeneous case. The enhanced heat conduction in this regime is partially caused by atoms with a high angular momentum spiraling in trajectories around the core of the cloud. Since atoms in these trajectories are almost collisionless they strongly contribute to the heat transfer. We observe a second, oscillating hydrodynamic mode, which we identify as a standing wave sound mode.

  20. Infrared thermography of a pulsating heat pipe: Flow regimes and multiple steady states

    E-Print Network [OSTI]

    Khandekar, Sameer

    Infrared thermography of a pulsating heat pipe: Flow regimes and multiple steady states V 400085, India h i g h l i g h t s PHP tested with varying heat powers under vertical orientation. Tube wall and inside fluid temperatures measured in the evaporator. Infrared temperature visualization

  1. Experimental Study of Heat Transfer and Flow Characteristics for a New Type of Air Heater

    E-Print Network [OSTI]

    Zheng, H.; Fan, X.; Li, A.

    2006-01-01T23:59:59.000Z

    . It is found that the integrated characteristics of heat transfer and flow friction increase with the hole's diameter at the same hole density (which is equal to the ratio of the hole's total area to the baffle's area), and the heat transfer rate increases...

  2. Experimental Study of Heat Transfer and Flow Characteristics for a New Type of Air Heater†

    E-Print Network [OSTI]

    Zheng, H.; Fan, X.; Li, A.

    2006-01-01T23:59:59.000Z

    . It is found that the integrated characteristics of heat transfer and flow friction increase with the hole's diameter at the same hole density (which is equal to the ratio of the hole's total area to the baffle's area), and the heat transfer rate increases...

  3. Quantity, quality, and availability of waste heat from United States thermal power generation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gingerich, Daniel B; Mauter, Meagan S

    2015-06-10T23:59:59.000Z

    Secondary application of unconverted heat produced during electric power generation has the potential to improve the life-cycle fuel efficiency of the electric power industry and the sectors it serves. This work quantifies the residual heat (also known as waste heat) generated by U.S. thermal power plants and assesses the intermittency and transport issues that must be considered when planning to utilize this heat. Combining Energy Information Administration plant-level data with literature-reported process efficiency data, we develop estimates of the unconverted heat flux from individual U.S. thermal power plants in 2012. Together these power plants discharged an estimated 18.9 billion GJthmore†Ľof residual heat in 2012, 4% of which was discharged at temperatures greater than 90 įC. We also characterize the temperature, spatial distribution, and temporal availability of this residual heat at the plant level and model the implications for the technical and economic feasibility of its end use. Increased implementation of flue gas desulfurization technologies at coal-fired facilities and the higher quality heat generated in the exhaust of natural gas fuel cycles are expected to increase the availability of residual heat generated by 10.6% in 2040.ę†less

  4. Quantity, quality, and availability of waste heat from United States thermal power generation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gingerich, Daniel B [Carnegie Mellon Univ., Pittsburgh, PA (United States); Mauter, Meagan S [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    2015-06-10T23:59:59.000Z

    Secondary application of unconverted heat produced during electric power generation has the potential to improve the life-cycle fuel efficiency of the electric power industry and the sectors it serves. This work quantifies the residual heat (also known as waste heat) generated by U.S. thermal power plants and assesses the intermittency and transport issues that must be considered when planning to utilize this heat. Combining Energy Information Administration plant-level data with literature-reported process efficiency data, we develop estimates of the unconverted heat flux from individual U.S. thermal power plants in 2012. Together these power plants discharged an estimated 18.9 billion GJth of residual heat in 2012, 4% of which was discharged at temperatures greater than 90 įC. We also characterize the temperature, spatial distribution, and temporal availability of this residual heat at the plant level and model the implications for the technical and economic feasibility of its end use. Increased implementation of flue gas desulfurization technologies at coal-fired facilities and the higher quality heat generated in the exhaust of natural gas fuel cycles are expected to increase the availability of residual heat generated by 10.6% in 2040.

  5. On Heating of Cluster Cooling Flows by Sound Waves

    E-Print Network [OSTI]

    Yutaka Fujita; Takeru Ken Suzuki

    2005-08-10T23:59:59.000Z

    We investigate heating of the cool core of a galaxy cluster through the dissipation of sound waves excited by the activities of the central active galactic nucleus (AGN). Using a weak shock theory, we show that this heating mechanism alone cannot reproduce observed temperature and density profiles of a cluster, because the dissipation length of the waves is much smaller than the size of the core and thus the wave energy is not distributed to the whole core. However, we find that if it is combined with thermal conduction from the hot outer layer of the cluster, the wave heating can reproduce the observational results.

  6. An Analysis of Heat and Fluid Flow Phenomena 1n Electroslag Welding

    E-Print Network [OSTI]

    Eagar, Thomas W.

    and temperature distri- bution~ are given for several idealized models of the electroslag welding process) ) An Analysis of Heat and Fluid Flow Phenomena 1n Electroslag Welding Two physical models created and fluid flow phenom- ena in metals processing operations have been applied to electroslag weld- ing

  7. ORIGINAL PAPER Flow Dynamics and Plasma Heating of Spheromaks in SSX

    E-Print Network [OSTI]

    Brown, Michael R.

    ORIGINAL PAPER Flow Dynamics and Plasma Heating of Spheromaks in SSX M. R. Brown √? C. D. Cothran √? from single dipole- trapped spheromaks and spheromak merging studies at SSX. Single spheromaks) copper flux conserver. Local spheromak flow is studied with two Mach probes (r1 ¬£ qi, r2 qi) calibrated

  8. Next Generation Nuclear Plant Steam Generator and Intermediate Heat Exchanger Materials Research and Development Plan

    SciTech Connect (OSTI)

    J. K. Wright

    2010-09-01T23:59:59.000Z

    DOE has selected the High Temperature Gas-cooled Reactor (HTGR) design for the Next Generation Nuclear Plant (NGNP) Project. The NGNP will demonstrate the use of nuclear power for electricity and hydrogen production. It will have an outlet gas temperature in the range of 900įC and a plant design service life of 60 years. The reactor design will be a graphite moderated, helium-cooled, prismatic or pebble-bed reactor and use low-enriched uranium, Tri-Isotopic (TRISO)-coated fuel. The plant size, reactor thermal power, and core configuration will ensure passive decay heat removal without fuel damage or radioactive material releases during accidents. The NGNP Materials Research and Development (R&D) Program is responsible for performing R&D on likely NGNP materials in support of the NGNP design, licensing, and construction activities. Todayís high-temperature alloys and associated ASME Codes for reactor applications are approved up to 760įC. However, some primary system components, such as the Intermediate Heat Exchanger (IHX) for the NGNP will require use of materials that can withstand higher temperatures. The thermal, environmental, and service life conditions of the NGNP will make selection and qualification of some high-temperature materials a significant challenge. Examples include materials for the core barrel and core internals, such as the control rod sleeves. The requirements of the materials for the IHX are among the most demanding. Selection of the technology and design configuration for the NGNP must consider both the cost and risk profiles to ensure that the demonstration plant establishes a sound foundation for future commercial deployments. The NGNP challenge is to achieve a significant advancement in nuclear technology while at the same time setting the stage for an economically viable deployment of the new technology in the commercial sector soon after 2020. A number of solid solution strengthened nickel based alloys have been considered for application in heat exchangers and core internals for the NGNP. The primary candidates are Inconel 617, Haynes 230, Incoloy 800H and Hastelloy XR. Based on the technical maturity, availability in required product forms, experience base, and high temperature mechanical properties all of the vendor pre-conceptual design studies have specified Alloy 617 as the material of choice for heat exchangers. Also a draft code case for Alloy 617 was developed previously. Although action was suspended before the code case was accepted by ASME, this draft code case provides a significant head start for achieving codification of the material. Similarly, Alloy 800H is the material of choice for control rod sleeves. In addition to the above listed considerations, Alloy 800H is already listed in the nuclear section of the ASME Code; although the maximum use temperature and time need to be increased.

  9. Heat Recovery from Coal Gasifiers

    E-Print Network [OSTI]

    Wen, H.; Lou, S. C.

    1981-01-01T23:59:59.000Z

    This paper deals with heat recovery from pressurized entrained and fixed bed coal gasifiers for steam generation. High temperature waste heat, from slagging entrained flow coal gasifier, can be recovered effectively in a series of radiant...

  10. Comparative Analysis of Natural Convection Flows Simulated by both the Conservation and Incompressible Forms of the Navier-Stokes Equations in a Differentially-Heated Square Cavity

    SciTech Connect (OSTI)

    Richard C. Martineau; Ray A. Berry; Aurťlia Esteve; Kurt D. Hamman; Dana A. Knoll; Ryosuke Park; William Taitano

    2009-01-01T23:59:59.000Z

    This report illustrates a comparative study to analyze the physical differences between numerical simulations obtained with both the conservation and incompressible forms of the Navier-Stokes equations for natural convection flows in simple geometries. The purpose of this study is to quantify how the incompressible flow assumption (which is based upon constant density advection, divergence-free flow, and the Boussinesq gravitational body force approximation) differs from the conservation form (which only assumes that the fluid is a continuum) when solving flows driven by gravity acting upon density variations resulting from local temperature gradients. Driving this study is the common use of the incompressible flow assumption in fluid flow simulations for nuclear power applications in natural convection flows subjected to a high heat flux (large temperature differences). A series of simulations were conducted on two-dimensional, differentially-heated rectangular geometries and modeled with both hydrodynamic formulations. From these simulations, the selected characterization parameters of maximum Nusselt number, average Nusselt number, and normalized pressure reduction were calculated. Comparisons of these parameters were made with available benchmark solutions for air with the ideal gas assumption at both low and high heat fluxes. Additionally, we generated body force, velocity, and divergence of velocity distributions to provide a basis for further analysis. The simulations and analysis were then extended to include helium at the Very High Temperature gas-cooled Reactor (VHTR) normal operating conditions. Our results show that the consequences of incorporating the incompressible flow assumption in high heat flux situations may lead to unrepresentative results. The results question the use of the incompressible flow assumption for simulating fluid flow in an operating nuclear reactor, where large temperature variations are present. The results show that the use of the incompressible flow assumption with the Boussinesq gravitational body force approximation should be restricted to flows where the density change of a fluid particle along a pathline is negligible.

  11. A Detailed Analysis of Guard-Heated Wall Shear Stress Sensors for Turbulent Flows Seyed Ali Ale Etrati Khosroshahi

    E-Print Network [OSTI]

    Victoria, University of

    A Detailed Analysis of Guard-Heated Wall Shear Stress Sensors for Turbulent Flows by Seyed Ali Ale A Detailed Analysis of Guard-Heated Wall Shear Stress Sensors for Turbulent Flows by Seyed Ali Ale Etrati-dimensional analysis of the performance of multi-element guard-heated hot-film wall shear stress microsensors

  12. Analytical modeling for the heat transfer in sheared flows of nanofluids

    E-Print Network [OSTI]

    Ferrari, Claudio; L'vov, Victor S; Procaccia, Itamar; Rudenko, Oleksii; Boonkkamp, J H M ten Thije; Toschi, Federico

    2012-01-01T23:59:59.000Z

    We developed a model for the enhancement of the heat flux by spherical and elongated nano- particles in sheared laminar flows of nano-fluids. Besides the heat flux carried by the nanoparticles the model accounts for the contribution of their rotation to the heat flux inside and outside the particles. The rotation of the nanoparticles has a twofold effect, it induces a fluid advection around the particle and it strongly influences the statistical distribution of particle orientations. These dynamical effects, which were not included in existing thermal models, are responsible for changing the thermal properties of flowing fluids as compared to quiescent fluids. The proposed model is strongly supported by extensive numerical simulations, demonstrating a potential increase of the heat flux far beyond the Maxwell-Garnet limit for the spherical nanoparticles. The road ahead which should lead towards robust predictive models of heat flux enhancement is discussed.

  13. Analytical modeling for the heat transfer in sheared flows of nanofluids

    E-Print Network [OSTI]

    Claudio Ferrari; Badr Kaoui; Victor S. L'vov; Itamar Procaccia; Oleksii Rudenko; J. H. M. ten Thije Boonkkamp; Federico Toschi

    2012-04-12T23:59:59.000Z

    We developed a model for the enhancement of the heat flux by spherical and elongated nano- particles in sheared laminar flows of nano-fluids. Besides the heat flux carried by the nanoparticles the model accounts for the contribution of their rotation to the heat flux inside and outside the particles. The rotation of the nanoparticles has a twofold effect, it induces a fluid advection around the particle and it strongly influences the statistical distribution of particle orientations. These dynamical effects, which were not included in existing thermal models, are responsible for changing the thermal properties of flowing fluids as compared to quiescent fluids. The proposed model is strongly supported by extensive numerical simulations, demonstrating a potential increase of the heat flux far beyond the Maxwell-Garnet limit for the spherical nanoparticles. The road ahead which should lead towards robust predictive models of heat flux enhancement is discussed.

  14. Heat generation by electronic current in a quantum dot spin-valve

    SciTech Connect (OSTI)

    Chi, Feng [School of Physical Science and Technology, Inner Mongolia University, Huhehaote 010023 (China); College of Engineering, Bohai University, Jinzhou 121013 (China); Sun, Lian-Liang [College of Science, North China University of Technology, Beijing 100041 (China); Guo, Yu [College of Engineering, Bohai University, Jinzhou 121013 (China)

    2014-10-28T23:59:59.000Z

    Electric-current-induced heat generation in an interacting single-level quantum dot connected to ferromagnetic leads with noncollinear magnetizations is theoretically investigated. We find that when the two leads' spin polarization rates are identical and much smaller than unit, the magnitude of the heat generation is almost monotonously enhanced as the angle between the leads' magnetic moments is varied from zero to ?, while the magnitude of the electric current is continuously suppressed. Moreover, the properties of the heat generation depend on the lead's spin polarization rate in different ways when the angle is varied. If at least one of the leads' spin polarization rate approaches to unit, the spin-valve effect of the heat generation is identical to that of the electric current. Now the previously found negative differential of the heat generation disappears when the angle approaches to ?. As compared to the current, the heat generation is more sensitive to the system's asymmetry when one of the electrodes is half-metallic in noncollinear configurations.

  15. Supplementary Information for Generation and reversal of surface flows by propagating waves

    E-Print Network [OSTI]

    Loss, Daniel

    Supplementary Information for Generation and reversal of surface flows by propagating waves-4) and Supplementary Figures 1-8. Generation and reversal of surface flows by propagating waves localized time-periodic perturbations of water surface generate waves propagating away from the plungers

  16. Improving heat capture for power generation in coal gasification plants

    E-Print Network [OSTI]

    Botros, Barbara Brenda

    2011-01-01T23:59:59.000Z

    Improving the steam cycle design to maximize power generation is demonstrated using pinch analysis targeting techniques. Previous work models the steam pressure level in composite curves based on its saturation temperature ...

  17. Modeling of ion heating from viscous damping of reconnection flows in the reversed field pinch

    SciTech Connect (OSTI)

    Svidzinski, V. A.; Fiksel, G.; Mirnov, V. V.; Prager, S. C. [Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas and University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

    2008-06-15T23:59:59.000Z

    Strong self-heating of ions is observed in the reversed field pinch (RFP). During a sawtooth crash in the Madison Symmetric Torus RFP, the ion temperature can spontaneously double in {approx}100 {mu}s. It is also observed that high Z impurities are heated more strongly than bulk ions. The possibility of ion heating due to tearing instabilities at sawtooth crash is examined. Heating scenarios due to viscous damping of strongly localized perpendicular and parallel flows driven in the vicinity of resonant surface in tearing mode are considered. Flow amplitudes and spatial scales are estimated from linear and nonlinear resistive magnetohydrodynamic modeling. The heating rates are found from kinetic models with different levels of approximation, up to solving kinetic equation with a Landau collision operator. Results show reasonable agreement of the modeled impurity heating rate with the experiment, while the estimated bulk ions heating is somewhat weaker than in the experiment. Further theoretical and experimental study are required for a more definite conclusion as to whether it is the main ion heating mechanism or if there is some other important ion heating scenario.

  18. Heat flow and thermotectonic problems of the central Ventura Basin, southern California

    SciTech Connect (OSTI)

    De Rito, R.F.; Lachenbruch, A.H.; Moses, T.H. Jr.; Munroe, R.J. (Geological Survey, Menlo Park, CA (USA))

    1989-01-10T23:59:59.000Z

    The Ventura Basin, southern Califronia, is located near the Big Bend area of the San Andreas fault system, within the Transverse Ranges physiographic province. Continuous equilibrium temperature logs were measured in 12 idle oil wells located within the onshore Ventura Avenue, San Miguelito, Filmore, Oxnard, and West Montalvo fields to an average depth of about 3100 m (10,200 feet). Thermal conductivities were measured on all available samples. Heat flows were calculated with the aid of a thermostratigraphic scheme based on correlative gradient intervals and average thermal conductivity for the appropriate units. Negative curvature of the Ventura Avenue temperature profiles may be explained by an increase in thermal conductivity associated with tectonic compaction of the underlying Pliocene clastic sequence. Temperature profiles at Fillmore are enigmatic but suggest highly unusual geotectonic conditions. Basinwide, heat flow averages about 48 mW/m{sup 2}, a value which is low relative to most of southern California. As heat flow does not vary systematically to the maximum measured depth of about 4 km, this anomaly is not easily explained in terms of hydrologic effect or recent uplift and erosion. However, a diminution of heat flow is an expectable consequence of the accumulation of cold sediments (up to 12 km) since Eocene time. If 70 mW/m{sub 2} is accepted as the background heat flow, then the sedimentation effect is probably sufficient to explain the anomaly.

  19. Emissivity corrected infrared method for imaging anomalous structural heat flows

    DOE Patents [OSTI]

    Del Grande, Nancy K. (San Leandro, CA); Durbin, Philip F. (Livermore, CA); Dolan, Kenneth W. (Livermore, CA); Perkins, Dwight E. (Livermore, CA)

    1995-01-01T23:59:59.000Z

    A method for detecting flaws in structures using dual band infrared radiation. Heat is applied to the structure being evaluated. The structure is scanned for two different wavelengths and data obtained in the form of images. Images are used to remove clutter to form a corrected image. The existence and nature of a flaw is determined by investigating a variety of features.

  20. Method and apparatus for enhanced heat recovery from steam generators and water heaters

    DOE Patents [OSTI]

    Knight, Richard A.; Rabovitser, Iosif K.; Wang, Dexin

    2006-06-27T23:59:59.000Z

    A heating system having a steam generator or water heater, at least one economizer, at least one condenser and at least one oxidant heater arranged in a manner so as to reduce the temperature and humidity of the exhaust gas (flue gas) stream and recover a major portion of the associated sensible and latent heat. The recovered heat is returned to the steam generator or water heater so as to increase the quantity of steam generated or water heated per quantity of fuel consumed. In addition, a portion of the water vapor produced by combustion of fuel is reclaimed for use as feed water, thereby reducing the make-up water requirement for the system.

  1. Time-delayed apparent excess heat generation in electrolysis fusion experiments

    SciTech Connect (OSTI)

    Kim, Y.E. (Purdue Univ., Lafayette, IN (United States). Dept. of Physics)

    1991-04-10T23:59:59.000Z

    This paper reports that in many recent electrolysis fusion experiments, excess heat, tritium, and neutron production have been reported as intermittent bursts. These burst phenomena are described in terms of a surface reaction mechanism involving hysteresis of deuterium solubility in palladium as a function of the metal temperature. Excess heat generation is shown to be attributable to a hitherto neglected time-delayed chemical process due to the solubility hysteresis of deuterium in palladium. Negative results of no apparent excess heat generation from light-water electrolysis experiments is attributed to the fact that the solubility hysteresis of hydrogen occurs at a higher temperature range than that for deuterium. Apparent excess heat generation is expected to be also observable in blank electrolysis experiments with light water at higher pressures.

  2. Flow boiling of water in a circular staggered micro-pin fin heat sink Santosh Krishnamurthy, Yoav Peles *

    E-Print Network [OSTI]

    Peles, Yoav

    across a bank of heated tube bundles, have shown that the local two-phase heat transfer coefficient across a tube bundle and determined the void fraction, the frictional pressure drop, and the local heatFlow boiling of water in a circular staggered micro-pin fin heat sink Santosh Krishnamurthy, Yoav

  3. FARM NET INCOME IMPACT OF SWITCHGRASS PRODUCTION AND CORN STOVER COLLECTION FOR HEAT AND POWER GENERATION

    E-Print Network [OSTI]

    Wisconsin at Madison, University of

    GENERATION by Mitchell A. Myhre A thesis submitted in partial fulfillment of the requirements for the degree and Corn Stover Collection for Heat and Power Generation Mitchell A. Myhre Advisor: Associate Professor. Last but not least I would like to thank my wife Lisa for her love and support. #12;iv Table

  4. An experimental study of endwall heat transfer enhancement for flow past staggered non-conducting pin fin arrays†

    E-Print Network [OSTI]

    Achanta, Vamsee Satish

    2004-09-30T23:59:59.000Z

    In this work, we study the enhanced endwall heat transfer for flow past non conducting pin fin arrays. The aim is to resolve the controversy over the heat transfer that is taking place from the endwall and the pin ...

  5. DECAY HEAT CONDITIONS OF CURRENT AND NEXT GENERATION REACTORS†

    E-Print Network [OSTI]

    Choe, JongSoo 1985-

    2012-05-04T23:59:59.000Z

    nitrate solution con- taining methanol and an additive, spherical droplets are produced by a vibration dropping technique. The diameter of uranyl nitrate droplet is determined by the combination of the #3;ow rate of metal solution and the frequency...2+Ar) IPyC coating (C3H6+Ar) SiC coating (CH3SiCl3+H2) OPyC coating (C3H6+Ar) Burnable poison Graphite block Graphite sleeve Fuel rod Fuel compact TRISO coated particle UO2 particle Uranyl nitrate solution Overcoat particle Fig. 2. Flow...

  6. Emissivity corrected infrared method for imaging anomalous structural heat flows

    DOE Patents [OSTI]

    Del Grande, N.K.; Durbin, P.F.; Dolan, K.W.; Perkins, D.E.

    1995-08-22T23:59:59.000Z

    A method for detecting flaws in structures using dual band infrared radiation is disclosed. Heat is applied to the structure being evaluated. The structure is scanned for two different wavelengths and data obtained in the form of images. Images are used to remove clutter to form a corrected image. The existence and nature of a flaw is determined by investigating a variety of features. 1 fig.

  7. Friedmann-like collapsing model of a radiating sphere with heat flow

    SciTech Connect (OSTI)

    Kolassis, C.A.; Santos, N.O.; Tsoubelis, D.

    1988-04-01T23:59:59.000Z

    This paper considers a spherical body consisting of a fluid with heat flow which radiates in its exterior a null fluid described by the outgoing Vaidya's metric. A Friedmann-like exact solution of the interior Einstein field equations is given. It is proved that this solution, matched with the outgoing Vaidya matric, represents a physically reasonble collapsing model which, when the heat flow is switched off, reduces to the well-known collapsing model with dust. The proposed model has the remarkable property that even if the heat flow is small, the horizon will never be formed because, before this happens, the collapsing body will be destroyed by opposite gradients of pressure. 6 references.

  8. Experimental study on corrugated cross-flow air-cooled plate heat exchangers

    SciTech Connect (OSTI)

    Kim, Minsung; Baik, Young-Jin; Park, Seong-Ryong; Ra, Ho-Sang [Solar Thermal and Geothermal Research Center, Korea Institute of Energy Research, Daejeon 305-343 (Korea); Lim, Hyug [Research and Development Center, LHE Co., Ltd., Gimhae 621-874 (Korea)

    2010-11-15T23:59:59.000Z

    Experimental study on cross-flow air-cooled plate heat exchangers (PHEs) was performed. The two prototype PHEs were manufactured in a stack of single-wave plates and double-wave plates in parallel. Cooling air flows through the PHEs in a crosswise direction against internal cooling water. The heat exchanger aims to substitute open-loop cooling towers with closed-loop water circulation, which guarantees cleanliness and compactness. In this study, the prototype PHEs were tested in a laboratory scale experiments. From the tests, double-wave PHE shows approximately 50% enhanced heat transfer performance compared to single-wave PHE. However, double-wave PHE costs 30% additional pressure drop. For commercialization, a wide channel design for air flow would be essential for reliable performance. (author)

  9. Counter flow cooling drier with integrated heat recovery

    DOE Patents [OSTI]

    Shivvers, Steve D. (Prole, IA)

    2009-08-18T23:59:59.000Z

    A drier apparatus for removing water or other liquids from various materials includes a mixer, drying chamber, separator and regenerator and a method for use of the apparatus. The material to be dried is mixed with a heated media to form a mixture which then passes through the chamber. While passing through the chamber, a comparatively cool fluid is passed counter current through the mixture so that the mixture becomes cooler and drier and the fluid becomes hotter and more saturated with moisture. The mixture is then separated into drier material and media. The media is transferred to the regenerator and heated therein by the hot fluid from the chamber and supplemental heat is supplied to bring the media to a preselected temperature for mixing with the incoming material to be dried. In a closed loop embodiment of the apparatus, the fluid is also recycled from the regenerator to the chamber and a chiller is utilized to reduce the temperature of the fluid to a preselected temperature and dew point temperature.

  10. Heat flow and subsurface temperature distributions in central and western New York. Volume 2

    SciTech Connect (OSTI)

    Hodge, D.S.; Fromm, K.A.

    1982-08-01T23:59:59.000Z

    Existing data in western and central New York indicates the possibility of a low-temperature, direct-use geothermal resource. This report evaluates the heat flow and provides a representation of temperatures at depth in this area. This has been done by: (1) analyzing known temperature distributions, (2) measuring the thermal conductivity of sedimentary rock units. Based on this information, areas of higher-than-normal heat flow and temperatures in possible geothermal source reservoirs are described to aid in targeting areas for the exploitation of geothermal energy in New York.

  11. TOUGH Simulations of the Updegraff's Set of Fluid and Heat Flow Problems

    SciTech Connect (OSTI)

    Moridis, G.J.; Pruess (editor), K.

    1992-11-01T23:59:59.000Z

    The TOUGH code [Pruess, 1987] for two-phase flow of water, air, and heat in penneable media has been exercised on a suite of test problems originally selected and simulated by C. D. Updegraff [1989]. These include five 'verification' problems for which analytical or numerical solutions are available, and three 'validation' problems that model laboratory fluid and heat flow experiments. All problems could be run without any code modifications (*). Good and efficient numerical performance, as well as accurate results were obtained throughout. Additional code verification and validation problems from the literature are briefly summarized, and suggestions are given for proper applications of TOUGH and related codes.

  12. DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 2

    SciTech Connect (OSTI)

    Not Available

    1992-06-01T23:59:59.000Z

    The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems.

  13. DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 1

    SciTech Connect (OSTI)

    Not Available

    1992-06-01T23:59:59.000Z

    The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems.

  14. DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 3

    SciTech Connect (OSTI)

    Not Available

    1992-06-01T23:59:59.000Z

    The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems.

  15. Time variability of AGN and heating of cooling flows

    E-Print Network [OSTI]

    Carlo Nipoti; James Binney

    2005-05-03T23:59:59.000Z

    There is increasing evidence that AGN mechanical feedback is important in the energetics of cooling flows in galaxies and galaxy clusters. We investigate the implications of the variability of AGN mechanical luminosity L_m on observations of cooling flows and radio galaxies in general. It is natural to assume that l=ln(L_m/L_x) is a Gaussian process. Then L_m will be log-normally distributed at fixed cooling luminosity L_x, and the variance in a measure of L_m will increase with the time-resolution of the measure. We test the consistency of these predictions with existing data. These tests hinge on the power spectrum of l(t). Monitoring of Seyfert galaxies combined with estimates of the duty cycle of quasars imply flicker noise spectra, similar to those of microquasars. We combine a sample of sources in cooling flows that have cavities with the assumption that the average mechanical luminosity of the AGN equals L_x. Given that the mechanical luminosities are characterized by flicker noise, we find that their spectral amplitudes lie between the estimated amplitudes of quasars and the measured values for the radio luminosities of microquasars. The model together with the observation that powerful radio galaxies lie within a narrow range in optical luminosity, predicts the luminosity function of radio galaxies, in agreement with observations. Forthcoming radio surveys will test the prediction that the luminosity function turns over at about the smallest luminosities so far probed. [Abridged

  16. Exhaust Heat Recovery for Rural Alaskan Diesel Generators | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny:RevisedAdvisoryStandardGenerationEducational OpportunitiesEngineRecovery:Energy

  17. Thermophysical property-related comparison criteria for nanofluid heat transfer enhancement in turbulent flow.

    SciTech Connect (OSTI)

    Yu, W.; France, D. M.; Timofeeva, E. V.; Singh, D.; Routbort, J. L. (Energy Systems); ( NE)

    2010-01-01T23:59:59.000Z

    Heat transfer enhancement criteria for nanofluids over their base fluids are presented based on three separate considerations: Reynolds number, flow velocity, and pumping power. Analyses presented show that, among the three comparisons, the constant pumping power comparison is the most unambiguous; the constant flow velocity comparison can be quite reasonable under certain conditions but the constant Reynolds number comparison (the most commonly used in the engineering literature for nanofluids) distorts the physical situation, and therefore, should not be used

  18. Columbia University flow instability experimental program: Volume 7. Single tube tests, critical heat flux test program

    SciTech Connect (OSTI)

    Dougherty, T.; Maciuca, C.; McAssey, E.V. Jr.; Reddy, D.G.; Yang, B.W.

    1992-09-01T23:59:59.000Z

    This report deals with critical heat flux (CHF) measurements in vertical down flow of water at low pressures in a round Inconel tube, 96 inches long and 0.62 inch inside diameter. A total of 28 CHF points were obtained. These data were found to correlate linearly with the single variable q, defined as the heat flux required to raise the enthalpy from the inlet value to the saturation value. These results were compared to the published results of Swedish investigators for vertical upflow of water at low pressures in round tubes of similar diameters and various lengths. The parameter q depends on the inlet enthalpy and is a nonlocal variable, thus this correlation is nonlocal unless the coefficients depend upon tube length in a particular prescribed manner. For the low pressure Swedish data, the coefficients are practically independent of length and hence the correlation is nonlocal. In the present investigation only one length was employed, so it is not possible to determine whether the correlation for these data is local or nonlocal, although there is reason to believe that it is local. The same correlation was applied to a large data base (thousands of CHF points) compiled from the published data of a number of groups and found to apply, with reasonable accuracy over a wide range of conditions, yielding sometimes local and sometimes nonlocal correlations. The basic philosophy of data analysis here was not to generate a single correlation which would reproduce all data, but to search for correlations which apply adequately over some range and which might have some mechanistic significance. The tentative conclusion is that at least two mechanisms appear operative, leading to two types of correlations, one local, the other nonlocal.

  19. HEAT TRANSFER IN STEADY-PERIODIC FLOWS OVER HEATED S. Yesilyurt, M. Ozcan, G. Goktug

    E-Print Network [OSTI]

    Yanikoglu, Berrin

    ; these two eddies are the well-known Karman vortex streets and as Re increases further they are very much) and Laake and Eckelmann (1989); similarly a group of authors studied vortex formation in flow around

  20. New flow boiling heat transfer model for hydrocarbons evaporating inside horizontal tubes

    SciTech Connect (OSTI)

    Chen, G. F.; Gong, M. Q.; Wu, J. F.; Zou, X. [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, 35, Beijing, 100190 (China); Wang, S. [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, 35, Beijing, 100190 (China); University of Chinese Academy of Science, No. 19 YuQuan Road, Beijing, 100049 (China)

    2014-01-29T23:59:59.000Z

    Hydrocarbons have high thermodynamic performances, belong to the group of natural refrigerants, and they are the main components in mixture Joule-Thomson low temperature refrigerators (MJTR). New evaluations of nucleate boiling contribution and nucleate boiling suppression factor in flow boiling heat transfer have been proposed for hydrocarbons. A forced convection heat transfer enhancement factor correlation incorporating liquid velocity has also been proposed. In addition, the comparisons of the new model and other classic models were made to evaluate its accuracy in heat transfer prediction.

  1. Electrically heated particulate filter with zoned exhaust flow control

    DOE Patents [OSTI]

    Gonze, Eugene V [Pinckney, MI

    2012-06-26T23:59:59.000Z

    A system includes a particulate matter (PM) filter that includes X zones. An electrical heater includes Y heater segments that are associated with respective ones of the X zones. The electrical heater is arranged upstream from and proximate with the PM filter. A valve assembly includes Z sections that are associated with respective ones of the X zones. A control module adjusts flow through each of the Z sections during regeneration of the PM filter via control of the valve assembly. X, Y and Z are integers.

  2. Compositionality in Synchronous Data Flow: Modular Code Generation from Hierarchical SDF Graphs

    E-Print Network [OSTI]

    Compositionality in Synchronous Data Flow: Modular Code Generation from Hierarchical SDF Graphs in Synchronous Data Flow: Modular Code Generation from Hierarchical SDF Graphs Stavros Tripakis, Dai Bui, Bert of California, Berkeley stavros, daib, eal@eecs.berkeley.edu October 20, 2009 Abstract Hierarchical SDF models

  3. Granular flow in pebble-bed nuclear reactors: Scaling, Dust Generation, and Stress

    E-Print Network [OSTI]

    Rycroft, Chris H.

    Granular flow in pebble-bed nuclear reactors: Scaling, Dust Generation, and Stress Chris H. Keywords: granular flow, dust generation, numerical methods 1. Introduction Pebble-bed nuclear reactors prototypes of pebble-bed reactors, significant quantities of graphite dust have been observed due to rubbing

  4. AIR-FLOW STRUCTURE IN THE VERY CLOSE VICINITY OF WIND GENERATED WATER-WAVES

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    the static pressure, / , the slope of the water waves, the air kinematic viscosity. Wave characteristics wereAIR-FLOW STRUCTURE IN THE VERY CLOSE VICINITY OF WIND GENERATED WATER-WAVES Hubert Branger1 the structure of the air flow in the very close vicinity of the water-surface above wind-generated waves. We

  5. System and method for generating current by selective electron heating

    DOE Patents [OSTI]

    Fisch, Nathaniel J. (Princeton, NJ); Boozer, Allen H. (Rocky Hill, NJ)

    1984-01-01T23:59:59.000Z

    A system for the generation of toroidal current in a plasma which is prepared in a toroidal magnetic field. The system utilizes the injection of high-frequency waves into the plasma by means of waveguides. The wave frequency and polarization are chosen such that when the waveguides are tilted in a predetermined fashion, the wave energy is absorbed preferentially by electrons traveling in one toroidal direction. The absorption of energy in this manner produces a toroidal electric current even when the injected waves themselves do not have substantial toroidal momentum. This current can be continuously maintained at modest cost in power and may be used to confine the plasma. The system can operate efficiently on fusion grade tokamak plasmas.

  6. An analysis of periodic heat flow through a plane slab

    E-Print Network [OSTI]

    Gibson, Daniel Morgan

    1958-01-01T23:59:59.000Z

    of the slice are shown in Figure 2. The corresponding ener~ balance is: kA(t l ? t )6Q kA(t l - t )aR or t I + t (M ? 2) + where 0 h A(t - t )gg kA(tl t g'9 i~N 'i&GY DlA('HAlill 10d HA1F-is&IC'. " Figu o 3 The ener, ~ dia?ram for thc half... + nc~. g 2 + 't2 (LYJ 2)+t g2g, 6 ~ cl. , ')61, 1 ~9 L. , to + tz(V, ? 2) ? , - t 1. + ~61. 1 2. - . ". ' + . '2O. O = ~6. g 61. 1 + 20. 0 2. - 2 + 262. 2Nbtb + ti(M - 2Nb ' ) + 2t4 i 2 . 2 0 +262. " 2. -2 . 2 -2 +2 20. 0 ~26. 0 Net heat...

  7. Time series power flow analysis for distribution connected PV generation.

    SciTech Connect (OSTI)

    Broderick, Robert Joseph; Quiroz, Jimmy Edward; Ellis, Abraham; Reno, Matthew J. [Georgia Institute of Technology, Atlanta, GA; Smith, Jeff [Electric Power Research Institute, Knoxville, TN; Dugan, Roger [Electric Power Research Institute, Knoxville, TN

    2013-01-01T23:59:59.000Z

    Distributed photovoltaic (PV) projects must go through an interconnection study process before connecting to the distribution grid. These studies are intended to identify the likely impacts and mitigation alternatives. In the majority of the cases, system impacts can be ruled out or mitigation can be identified without an involved study, through a screening process or a simple supplemental review study. For some proposed projects, expensive and time-consuming interconnection studies are required. The challenges to performing the studies are twofold. First, every study scenario is potentially unique, as the studies are often highly specific to the amount of PV generation capacity that varies greatly from feeder to feeder and is often unevenly distributed along the same feeder. This can cause location-specific impacts and mitigations. The second challenge is the inherent variability in PV power output which can interact with feeder operation in complex ways, by affecting the operation of voltage regulation and protection devices. The typical simulation tools and methods in use today for distribution system planning are often not adequate to accurately assess these potential impacts. This report demonstrates how quasi-static time series (QSTS) simulation and high time-resolution data can be used to assess the potential impacts in a more comprehensive manner. The QSTS simulations are applied to a set of sample feeders with high PV deployment to illustrate the usefulness of the approach. The report describes methods that can help determine how PV affects distribution system operations. The simulation results are focused on enhancing the understanding of the underlying technical issues. The examples also highlight the steps needed to perform QSTS simulation and describe the data needed to drive the simulations. The goal of this report is to make the methodology of time series power flow analysis readily accessible to utilities and others responsible for evaluating potential PV impacts.

  8. GMINC - A MESH GENERATOR FOR FLOW SIMULATIONS IN FRACTURED RESERVOIRS

    E-Print Network [OSTI]

    Pruess, K.

    2010-01-01T23:59:59.000Z

    Flow in Naturally Fractured Reservoirs, Society of Petroleumfor Naturally Fractured Reservoirs, paper SPE-11688,Determining Naturally Fractured Reservoir Properties by Well

  9. November 28, 2006 Seismologists get handle on heat flow deep in earth

    E-Print Network [OSTI]

    Garnero, Ed

    November 28, 2006 Seismologists get handle on heat flow deep in earth Earth's interior placid inner Earth as a dynamic environment filled with exotic materials and substances roiling under that has an impact on what happens on our planet's surface. The latest evidence of this dynamic inner Earth

  10. UW -Center for Intelligent Materials and Systems 1 1-D Heat Flow Measurement

    E-Print Network [OSTI]

    Taya, Minoru

    : Calibrate Seebeck Coefficient for TFTC(Thin Film Thermocouples) x y Heater (70įC) Water (19įC) #12;UW ANSYS Simulation Used Data Water Temp. 2 Measured Temp. (Channel 14, 15) Heater size Assumption. Factor 2.258 #12;UW - Center for Intelligent Materials and Systems 3 2-D Heat Flow Measurement x y Heater

  11. Disorder-induced mobility edges and heat flow control in anharmonic acoustic chains

    E-Print Network [OSTI]

    Flach, Sergej

    in cutting-edge fields of research from across the whole of physics. Each compilation is led by its own CoOFFPRINT Disorder-induced mobility edges and heat flow control in anharmonic acoustic chains M acceptance decisions 1 Impact Factor ­ The 2009 Impact Factor increased by 31% to 2.893; your work

  12. Experimental shellside flow visualization in a shell and tube heat exchanger†

    E-Print Network [OSTI]

    Fischer, Matthew Winslow

    1998-01-01T23:59:59.000Z

    information in the shellside flow. A scale-model shell and tube heat exchanger with an outer diameter of 30.5 cm and a length of 61 cm was designed and constructed out of acrylic. Water was utilized as the working fluid and flowrates ranging from 0.32 to 2...

  13. Convective Heat Transfer and Reference Free-stream Temperature Determination near the Casing of an Axial Flow

    E-Print Network [OSTI]

    Camci, Cengiz

    of an Axial Flow Turbine B. Gumusel 2 and C. Camci 1 Turbomachinery Aero-Heat Transfer Laboratory Department on the casing of an axial flow turbine. The goal is to develop an accurate steady-state heat transfer method for the comparison of various casing surface and tip designs used for turbine performance improvements. The free

  14. Comparison of strongly heat-driven flow codes for unsaturated media

    SciTech Connect (OSTI)

    Updegraff, C.D.

    1989-08-01T23:59:59.000Z

    Under the sponsorship of the US Nuclear Regulatory Commission, Sandia National Laboratories (SNL) is developing a performance assessment methodology for the analysis of long-term disposal of high-level radioactive waste (HLW) in unsaturated welded tuff. As part of this effort, SNL evaluated existing strongly heat-driven flow computer codes for simulating ground-water flow in unsaturated media. The three codes tested, NORIA, PETROS, and TOUGH, were compared against a suite of problems for which analytical and numerical solutions or experimental results exist. The problems were selected to test the abilities of the codes to simulate situations ranging from simple, uncoupled processes, such as two-phase flow or heat transfer, to fully coupled processes, such as vaporization caused by high temperatures. In general, all three codes were found to be difficult to use because of (1) built-in time stepping criteria, (2) the treatment of boundary conditions, and (3) handling of evaporation/condensation problems. A drawback of the study was that adequate problems related to expected repository conditions were not available in the literature. Nevertheless, the results of this study suggest the need for thorough investigations of the impact of heat on the flow field in the vicinity of an unsaturated HLW repository. Recommendations are to develop a new flow code combining the best features of these three codes and eliminating the worst ones. 19 refs., 49 figs.

  15. THE DEFINITION OF ENGINEERING DEVELOPMENT AND RESEARCH PROBLEMS RELATING TO THE USE OF GEOTHERMAL FLUIDS FOR ELECTRIC POWER GENERATION AND NONELECTRIC HEATING

    E-Print Network [OSTI]

    Apps, J.A.

    2011-01-01T23:59:59.000Z

    GENERATION AND NONELECTRIC HEATING I J. A. Apps I NTRODUCT IGENERATION AND NONELECTRIC HEATING li I J. A. Apps NovemberGENERATION AND NONELECTRIC HEATING J. A. Apps Earth Sciences

  16. Local heat transfer and pressure drop measurements in a wavy channel with and without flow disturbers

    SciTech Connect (OSTI)

    Dini, S.; Kmelius, D. [Western New England College, Springfield, MA (United States); Saniei, N. [Southern Illinois Univ., Edwardsville, IL (United States)

    1995-09-01T23:59:59.000Z

    Experiments have been performed to measure local heat transfer coefficients and pressure drop in a wavy channel for Reynolds numbers of 2,900 and 7,000. Additionally, the effect of flow disturbers mounted on the first two peaks on one surface was investigated. The transient method and liquid crystals were used for the local heat transfer measurements. Initial experimental results indicate that addition of ribs into the passage stimulates flow instabilities which enhance the heat transfer performance with moderate effect on pressure drop. Measurements were conducted on a 6 in x 3/8 in x 12 in wavy channel with a wave length of one inch. The highest local heat transfer was detected on the second, followed by the third and fourth peaks at Re = 7000; wheras for Re = 2900 the highest heat transfer was along the next peak detected immediately after the disturbers. The experimental results observed in this study suggest that ribbed passages would yield higher heat transfer with moderate change in pressure drop compared with non-ribbed channels.

  17. Boiling heat transfer in a vertical microchannel: Local estimation during flow boiling with a non intrusive method

    E-Print Network [OSTI]

    Boiling heat transfer in a vertical microchannel: Local estimation during flow boiling with a non the results of experimental and numerical studies concerning boiling heat transfer inside vertical in minichannels for several gravity levels (Ķg, 1g, 2g). To fully understand the high heat transfer potential

  18. Fluid and heat flow in gas-rich geothermal reservoirs

    SciTech Connect (OSTI)

    O'Sullivan, M.J.; Bodvarsson, G.S.; Pruess, K.; Blakeley, M.R.

    1983-07-01T23:59:59.000Z

    Numerical-simulation techniques are used to study the effects of noncondensible gases (CO/sub 2/) on geothermal reservoir behavior in the natural state and during exploitation. It is shown that the presence of CO/sub 2/ has large effects on the thermodynamic conditions of a reservoir in the natural state, especially on temperature distributions and phase compositions. The gas will expand two-phase zones and increase gas saturations to enable flow of CO/sub 2/ through the system. During exploitation, the early pressure drop is primarily due to degassing of the system. This process can cause a very rapid initial pressure drop, on the order of tens of bars, depending upon the initial partial pressure of CO/sub 2/. The following gas content from wells can provide information on in-place gas saturations and relative permeability curves that apply at a given geothermal resource. Site-specific studies are made for the gas-rich two-phase reservoir at the Ohaki geothermal field in New Zealand. A simple lumped-parameter model and a vertical column model are applied to the field data. The results obtained agree well with the natural thermodynamic state of the Ohaki field (pressure and temperature profiles) and a partial pressure of 15 to 25 bars is calculated in the primary reservoirs. The models also agree reasonably well with field data obtained during exploitation of the field. The treatment of thermophysical properties of H/sub 2/O-CO/sub 2/ mixtures for different phase compositions is summarized.

  19. Non-uniform Heat Generation in Micro Catalytic Combustor Takashi Okamasa*, Yuji Suzuki, and Nobuhide Kasagi

    E-Print Network [OSTI]

    Kasagi, Nobuhide

    Non-uniform Heat Generation in Micro Catalytic Combustor Takashi Okamasa*, Yuji Suzuki@thtlab.t.u-tokyo.ac.jp Abstract We developed a micro catalytic combustor using high-precision ceramic tape-casting technology and nano-porous alumina catalyst layer. It is found that failure of the ceramic combustor occurs due

  20. Simulated Surface-Induced Thrombin Generation in a Flow Field

    E-Print Network [OSTI]

    Jordan, S.W.

    A computational model of blood coagulation is presented with particular emphasis on the regulatory effects of blood flow, spatial distribution of tissue factor (TF), and the importance of the thrombomodulin-activated protein ...

  1. GREENHOUSE GAS REDUCTION POTENTIAL WITH COMBINED HEAT AND POWER WITH DISTRIBUTED GENERATION PRIME MOVERS - ASME 2012

    SciTech Connect (OSTI)

    Curran, Scott [ORNL; Theiss, Timothy J [ORNL; Bunce, Michael [ORNL

    2012-01-01T23:59:59.000Z

    Pending or recently enacted greenhouse gas regulations and mandates are leading to the need for current and feasible GHG reduction solutions including combined heat and power (CHP). Distributed generation using advanced reciprocating engines, gas turbines, microturbines and fuel cells has been shown to reduce greenhouse gases (GHG) compared to the U.S. electrical generation mix due to the use of natural gas and high electrical generation efficiencies of these prime movers. Many of these prime movers are also well suited for use in CHP systems which recover heat generated during combustion or energy conversion. CHP increases the total efficiency of the prime mover by recovering waste heat for generating electricity, replacing process steam, hot water for buildings or even cooling via absorption chilling. The increased efficiency of CHP systems further reduces GHG emissions compared to systems which do not recover waste thermal energy. Current GHG mandates within the U.S Federal sector and looming GHG legislation for states puts an emphasis on understanding the GHG reduction potential of such systems. This study compares the GHG savings from various state-of-the- art prime movers. GHG reductions from commercially available prime movers in the 1-5 MW class including, various industrial fuel cells, large and small gas turbines, micro turbines and reciprocating gas engines with and without CHP are compared to centralized electricity generation including the U.S. mix and the best available technology with natural gas combined cycle power plants. The findings show significant GHG saving potential with the use of CHP. Also provided is an exploration of the accounting methodology for GHG reductions with CHP and the sensitivity of such analyses to electrical generation efficiency, emissions factors and most importantly recoverable heat and thermal recovery efficiency from the CHP system.

  2. Optimal selection of on-site generation with combined heat andpower applications

    SciTech Connect (OSTI)

    Siddiqui, Afzal S.; Marnay, Chris; Bailey, Owen; HamachiLaCommare, Kristina

    2004-11-30T23:59:59.000Z

    While demand for electricity continues to grow, expansion of the traditional electricity supply system, or macrogrid, is constrained and is unlikely to keep pace with the growing thirst western economies have for electricity. Furthermore, no compelling case has been made that perpetual improvement in the overall power quality and reliability (PQR)delivered is technically possible or economically desirable. An alternative path to providing high PQR for sensitive loads would generate close to them in microgrids, such as the Consortium for Electricity Reliability Technology Solutions (CERTS) Microgrid. Distributed generation would alleviate the pressure for endless improvement in macrogrid PQR and might allow the establishment of a sounder economically based level of universal grid service. Energy conversion from available fuels to electricity close to loads can also provide combined heat and power (CHP) opportunities that can significantly improve the economics of small-scale on-site power generation, especially in hot climates when the waste heat serves absorption cycle cooling equipment that displaces expensive on-peak electricity. An optimization model, the Distributed Energy Resources Customer Adoption Model (DER-CAM), developed at Berkeley Lab identifies the energy bill minimizing combination of on-site generation and heat recovery equipment for sites, given their electricity and heat requirements, the tariffs they face, and a menu of available equipment. DER-CAM is used to conduct a systemic energy analysis of a southern California naval base building and demonstrates atypical current economic on-site power opportunity. Results achieve cost reductions of about 15 percent with DER, depending on the tariff.Furthermore, almost all of the energy is provided on-site, indicating that modest cost savings can be achieved when the microgrid is free to select distributed generation and heat recovery equipment in order to minimize its over all costs.

  3. Parametric design study of ``mini-generator`` with 6-watt heat source

    SciTech Connect (OSTI)

    Schock, A.; Or, C.T. [Orbital Sciences Corporation, 20301 Century Blvd., Germantown, Maryland 20874 (United States)

    1995-01-20T23:59:59.000Z

    The Fairchild study showed that generator designs based on a single 1-watt RHU had very poor thermal efficiencies. At their optimum operating point, more than half of the generated heat was lost through the thermal insulation. This resulted in system efficiency of only 2.2%, compared to 7.2% for current Radioisotope Thermoelectric Generators (RTGs). Moreover, there were serious doubts about the fabricability of the required multicouples, particularly of the series/parallel connections between the large number (900) of thermoelectric legs of very small cross-section (0.21 mm square). All in all, the preceding paper showed that neither JPL`s Power Stick design nor the Fairchild-generated derivatives based on the 1-watt heat source looked promising. The present paper describes a similar parametric study of a mini-generator based on a 6-watt heat source, and compares its performance and fabricability to that of the optimum Power Stick derivative and of the current RTG design for the same mission. {copyright} 1995 {ital American} {ital Institute} {ital of} {ital Physics}

  4. Simulation of FCC riser flow with multiphase heat transfer and cracking reactions.

    SciTech Connect (OSTI)

    Chang, S. L.; Zhou, C. Q.; Energy Systems

    2003-08-01T23:59:59.000Z

    A validated Computational Fluid Dynamics (CFD) code ICRKFLO was developed for simulations of three-dimensional three-phase reacting flows in Fluid Catalytic Cracking (FCC) riser reactors. It calculates the product yields based on local flow properties by solving the fundamental conservation principles of mass, momentum, and energy for the flow properties associated with the gas, liquid, and solid phases. Unique phenomenological models and numerical techniques were developed specifically for the FCC flow simulation. The models include a spray vaporization model, a particle-solid interaction model, and an interfacial heat transfer model. The numerical techniques include a time-integral approach to overcome numerical stiffness problems in chemical kinetics rate calculations and a hybrid hydrodynamic-kinetic treatment to facilitate detailed kinetics calculations of cracking reactions. ICRKFLO has been validated with extensive test data from two pilot and one commercial FCC units. It is proven to be useful for advanced development of FCC riser reactors.

  5. Heat Transfer and Thermophotovoltaic Power Generation in Oil-fired Heating Systems

    SciTech Connect (OSTI)

    Butcher, T.; Hammonds, J.S.; Horne, E.; Kamath, B.; Carpenter, J.; Woods, D.R.

    2010-10-21T23:59:59.000Z

    The focus of this study is the production of electric power in an oil-fired, residential heatingsystem using thermophotovoltaic (TPV) conversion devices. This work uses experimental, computational, and analytical methods to investigate thermal mechanisms that drive electric power production in the TPV systems. An objective of this work is to produce results that will lead to the development of systems that generate enough electricity such that the boiler is self-powering. An important design constraint employed in this investigation is the use of conventional, yellow-flame oil burners, integrated with a typical boiler. The power production target for the systems developed here is 100 W - the power requirement for a boiler that uses low-power auxiliary components. The important heattransfer coupling mechanisms that drive power production in the systems studied are discussed. The results of this work may lead to the development of systems that export power to the home electric system.

  6. Flow and Temperature Fields Generated by a Thermally Activated Interventional Vascular Device

    E-Print Network [OSTI]

    McCurrin, Casey

    2012-10-19T23:59:59.000Z

    ........................ 51 24 Zoom of Previous Image to Show Heating Effects ................................... 52 25 Comparisons between Analytical and CFD Annulus Profiles .................. 53 26 Temperature Field for Low Flow... by Sakakibara et al. [22] and Coolen et al. [23] in which the investigated temperature ranges were 40 K and 0.7 K, respectively. Two different CFD codes [24] for analyzing the case of a heated cylinder show qualitative agreement with experimental results from...

  7. Compare Energy Use in Variable Refrigerant Flow Heat Pumps Field Demonstration and Computer Model

    SciTech Connect (OSTI)

    Sharma, Chandan; Raustad, Richard

    2013-06-01T23:59:59.000Z

    Variable Refrigerant Flow (VRF) heat pumps are often regarded as energy efficient air-conditioning systems which offer electricity savings as well as reduction in peak electric demand while providing improved individual zone setpoint control. One of the key advantages of VRF systems is minimal duct losses which provide significant reduction in energy use and duct space. However, there is limited data available to show their actual performance in the field. Since VRF systems are increasingly gaining market share in the US, it is highly desirable to have more actual field performance data of these systems. An effort was made in this direction to monitor VRF system performance over an extended period of time in a US national lab test facility. Due to increasing demand by the energy modeling community, an empirical model to simulate VRF systems was implemented in the building simulation program EnergyPlus. This paper presents the comparison of energy consumption as measured in the national lab and as predicted by the program. For increased accuracy in the comparison, a customized weather file was created by using measured outdoor temperature and relative humidity at the test facility. Other inputs to the model included building construction, VRF system model based on lab measured performance, occupancy of the building, lighting/plug loads, and thermostat set-points etc. Infiltration model inputs were adjusted in the beginning to tune the computer model and then subsequent field measurements were compared to the simulation results. Differences between the computer model results and actual field measurements are discussed. The computer generated VRF performance closely resembled the field measurements.

  8. Heat flow patterns of the North American continent: A discussion of the DNAG Geothermal Map of North America

    SciTech Connect (OSTI)

    Blackwell, David D.; Steele, John L.; Carter, Larry C.

    1990-01-01T23:59:59.000Z

    The large and small-scale geothermal features of the North American continent and surrounding ocean areas illustrated on the new 1:5,000,000 DNAG Geothermal Map of North America are summarized. Sources for the data included on the map are given. The types of data included are heat flow sites coded by value, contours of heat flow with a color fill, areas of major groundwater effects on regional heat flow, the top-of-geopressure in the Gulf Coast region, temperature on the Dakota aquifer in the midcontinent, location of major hot springs and geothermal systems, and major center of Quaternary and Holocene volcanism. The large scale heat flow pattern that is well known for the conterminous United States and Canada of normal heat flow east of the Cordillera and generally high heat flow west of the front of the Cordillera dominates the continental portion of the map. However, details of the heat flow variations are also seen and are discussed briefly in this and the accompanying papers.

  9. Shear flow generation by drift waves revisited P. N. Guzdar and R. G. Kleva

    E-Print Network [OSTI]

    Rubloff, Gary W.

    Shear flow generation by drift waves revisited P. N. Guzdar and R. G. Kleva Institute for Plasma Research, University of Maryland, College Park, Maryland 20742-3511 Liu Chen Department of Physics

  10. Sealable stagnation flow geometries for the uniform deposition of materials and heat

    DOE Patents [OSTI]

    McCarty, Kevin F. (Livermore, CA); Kee, Robert J. (Livermore, CA); Lutz, Andrew E. (Alamo, CA); Meeks, Ellen (Livermore, CA)

    2001-01-01T23:59:59.000Z

    The present invention employs a constrained stagnation flow geometry apparatus to achieve the uniform deposition of materials or heat. The present invention maximizes uniform fluxes of reactant gases to flat surfaces while minimizing the use of reagents and finite dimension edge effects. This results, among other things, in large area continuous films that are uniform in thickness, composition and structure which is important in chemical vapor deposition processes such as would be used for the fabrication of semiconductors.

  11. Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

    SciTech Connect (OSTI)

    Hong, Tainzhen; Liu, Xaiobing

    2009-11-01T23:59:59.000Z

    With the current movement toward net zero energy buildings, many technologies are promoted with emphasis on their superior energy efficiency. The variable refrigerant flow (VRF) and ground source heat pump (GSHP) systems are probably the most competitive technologies among these. However, there are few studies reporting the energy efficiency of VRF systems compared with GSHP systems. In this article, a preliminary comparison of energy efficiency between the air-source VRF and GSHP systems is presented. The computer simulation results show that GSHP system is more energy efficient than the air-source VRF system for conditioning a small office building in two selected US climates. In general, GSHP system is more energy efficient than the air-source VRV system, especially when the building has significant heating loads. For buildings with less heating loads, the GSHP system could still perform better than the air-source VRF system in terms of energy efficiency, but the resulting energy savings may be marginal.

  12. High-heat-flux removal by phase-change fluid and particulate flow

    SciTech Connect (OSTI)

    Gorbis, Z.R.; Raffray, A.R.; Abdou, M.A. (Univ. of California, Los Angeles (United States))

    1993-07-01T23:59:59.000Z

    A new concept based on particulate flow in which either or both the particulates and the fluid could undergo phase changes is proposed. The presence of particulates provides not only a mechanism for additional heat removal through phase change but also the potential for increasing the rate of heat transfer by enhancing convection through surface region/bulk [open quotes]mixing[close quotes], by enhancing radiation, particularly for high-temperature cases; and for the case of multiphase fluid, by enhancing the boiling process. One particularly interesting coolant system based on this concept is [open quotes]subcooled boiling water-ice particulate[close quotes] flow. A preliminary analysis of this coolant system is presented, the results of which indicate that such a coolant system is better applied for cooling of relatively small surface areas with high local heat fluxes, where a conventional cooling system would come short of providing the required heat removal at acceptable coolant pressure levels. 14 refs., 8 figs.

  13. Proceedings of the Workshop on Numerical Modeling of Thermohydrological Flow in Fractured Rock Masses, Feb. 19-20, 1980, Berkeley, CA

    E-Print Network [OSTI]

    Witherspoon, P.A.

    2010-01-01T23:59:59.000Z

    buoyancy flow induced by the waste heat will per≠ sist overWith the emplacement of waste heat sources, buoyancy flows wformations. ' The waste will generate heat which raises the

  14. A preliminary assessment of the effects of groundwater flow on closed-loop ground source heat pump systems

    SciTech Connect (OSTI)

    Chiasson, A.D.; Rees, S.J.; Spitler, J.D.

    2000-07-01T23:59:59.000Z

    A preliminary study has been made of the effects of groundwater flow on the heat transfer characteristics of vertical closed-loop heat exchangers and the ability of current design and in-situ thermal conductivity measurement techniques to deal with these effects. It is shown that an initial assessment of the significance of groundwater flow can be made by examining the Peclet number of the flow. A finite-element numerical groundwater flow and heat transfer model has been used to simulate the effects of groundwater flow on a single closed-loop heat exchanger in various geologic materials. These simulations show that advection of heat by groundwater flow significantly enhances heat transfer in geologic materials with high hydraulic conductivity, such as sands, gravels, and rocks exhibiting fractures and solution channels. Simulation data were also used to derive effective thermal conductivities with an in-situ thermal conductivity estimation procedure. These data were used to design borehole fields of different depths for a small commercial building. The performance of these borehole field designs was investigated by simulating each borehole field using the pre-calculated building loads over a ten-year period. Results of these simulations, in terms of the minimum and peak loop temperatures, were used to examine the ability of current design methods to produce workable and efficient designs under a range of groundwater flow conditions.

  15. Simulation of hydration/dehydration of CaO/Ca(OH){sub 2} chemical heat pump reactor for cold/hot heat generation

    SciTech Connect (OSTI)

    Ogura, Hironao; Shimojyo, Rui; Kage, Hiroyuki; Matsuno, Yoshizo; Mujumdar, A.S.

    1999-09-01T23:59:59.000Z

    A chemical heat pump (CHP) utilizes reversible reactions involving significant endothermic and exothermic heats of reaction in order to develop a heat pump effect by storing and releasing energy while transforming it from chemical to thermal energy and vice versa. In this paper, the authors present a mathematical model and its numerical solution for the heat and mass transport phenomena occurring in the reactant particle bed of the CHP for heat storage and cold/hot heat generation based on the CaO/Ca(OH){sub 2} reversible hydration/dehydration reaction. Transient conservation equations of mass and energy transport including chemical kinetics are solved numerically subject to appropriate boundary and initial conditions to examine the influence of the mass transfer resistance on the overall performance of this CHP configuration. These results are presented and discussed with the aim of enhancing the CHP performance in the next generation reactor designs. The CHP can store thermal energy in industrial waste heat, solar heat, terrestrial heat, etc. in the form of chemical energy, and release it at various temperature levels during the heat-demand period.

  16. Ionic Liquids for Utilization of Waste Heat from Distributed Power Generation Systems

    SciTech Connect (OSTI)

    Joan F. Brennecke; Mihir Sen; Edward J. Maginn; Samuel Paolucci; Mark A. Stadtherr; Peter T. Disser; Mike Zdyb

    2009-01-11T23:59:59.000Z

    The objective of this research project was the development of ionic liquids to capture and utilize waste heat from distributed power generation systems. Ionic Liquids (ILs) are organic salts that are liquid at room temperature and they have the potential to make fundamental and far-reaching changes in the way we use energy. In particular, the focus of this project was fundamental research on the potential use of IL/CO2 mixtures in absorption-refrigeration systems. Such systems can provide cooling by utilizing waste heat from various sources, including distributed power generation. The basic objectives of the research were to design and synthesize ILs appropriate for the task, to measure and model thermophysical properties and phase behavior of ILs and IL/CO2 mixtures, and to model the performance of IL/CO2 absorption-refrigeration systems.

  17. Numerical and experimental investigation of melting with internal heat generation within cylindrical enclosures

    SciTech Connect (OSTI)

    Amber Shrivastava; Brian Williams; Ali S. Siahpush; Bruce Savage; John Crepeau

    2014-06-01T23:59:59.000Z

    There have been significant efforts by the heat transfer community to investigate the melting phenomenon of materials. These efforts have included the analytical development of equations to represent melting, numerical development of computer codes to assist in modeling the phenomena, and collection of experimental data. The understanding of the melting phenomenon has application in several areas of interest, for example, the melting of a Phase Change Material (PCM) used as a thermal storage medium as well as the melting of the fuel bundle in a nuclear power plant during an accident scenario. The objective of this research is two-fold. First a numerical investigation, using computational fluid dynamics (CFD), of melting with internal heat generation for a vertical cylindrical geometry is presented. Second, to the best of authors knowledge, there are very limited number of engineering experimental results available for the case of melting with Internal Heat Generation (IHG). An experiment was performed to produce such data using resistive, or Joule, heating as the IHG mechanism. The numerical results are compared against the experimental results and showed favorable correlation. Uncertainties in the numerical and experimental analysis are discussed. Based on the numerical and experimental analysis, recommendations are made for future work.

  18. Thermoelectric energy converter for generation of electricity from low-grade heat

    DOE Patents [OSTI]

    Jayadev, T.S.; Benson, D.K.

    1980-05-27T23:59:59.000Z

    A thermoelectric energy conversion device which includes a plurality of thermoelectric elements is described. A hot liquid is supplied to one side of each element and a cold liquid is supplied to the other side of each element. The thermoelectric generator may be utilized to produce power from low-grade heat sources such as ocean thermal gradients, solar ponds, and low-grade geothermal resources. (WHK)

  19. Power Flow Analysis Algorithm for Islanded LV Microgrids Including Distributed Generator Units with

    E-Print Network [OSTI]

    Chaudhary, Sanjay

    Power Flow Analysis Algorithm for Islanded LV Microgrids Including Distributed Generator Units With larger portion of growing electricity demand which is being fed through distributed generation (DG power system. Being able to operate in both grid-connected and islanded mode, a microgrid manages

  20. Prediction of turbulent flow and heat transfer in a ribbed rectangular duct with and without rotation

    SciTech Connect (OSTI)

    Prakash, C.; Zerkle, R. [General Electric Co., Cincinnati, OH (United States)

    1995-04-01T23:59:59.000Z

    The present study deals with the numerical prediction of turbulent flow and heat transfer in a 2:1 aspect ratio rectangular duct with ribs don the two shorter sides. The ribs are of square cross section, staggered and aligned normal (90 deg) to the main flow direction. The ratio of rib height to duct hydraulic diameter equals 0.063, and the ratio of rib spacing to rib height equals 10. The duct may be stationary or rotating. The axis of rotation is normal to the axis of the duct and parallel to the ribbed walls (i.e., the ribbed walls form the leading and the trailing faces). The problem is three dimensional and fully elliptic; hence, for computational economy, the present analysis deals only with a periodically fully developed situation where the calculation domain is limited to the region between two adjacent ribs. Turbulence is modeled with the {kappa}-{epsilon} model in conjunction with wall functions. However, since the rib height is small, use of wall functions necessitates that the Reynolds number be kept high. (Attempts to use a two-layer model that permits integration to the wall did not yield satisfactory results and such modeling issues are discussed at length.) Computations are made here for Reynolds number in the range 30,000--100,000 and for Rotation number = 0 (stationary), 0.06, and 0.12. For the stationary case, the predicted heat transfer agrees well with the experimental correlations. Due to the Coriolis-induced secondary flow, rotation is found to enhance heat transfer from the trailing and the side walls, while decreasing heat transfer from the leading face. Relative to the corresponding stationary case, the effect of rotation is found to be less for a ribbed channel as compared to a smooth channel.

  1. RELAP5-3D Modeling of Heat Transfer Components (Intermediate Heat Exchanger and Helical-Coil Steam Generator) for NGNP Application

    SciTech Connect (OSTI)

    N. A. Anderson; P. Sabharwall

    2014-01-01T23:59:59.000Z

    The Next Generation Nuclear Plant project is aimed at the research and development of a helium-cooled high-temperature gas reactor that could generate both electricity and process heat for the production of hydrogen. The heat from the high-temperature primary loop must be transferred via an intermediate heat exchanger to a secondary loop. Using RELAP5-3D, a model was developed for two of the heat exchanger options a printed-circuit heat exchanger and a helical-coil steam generator. The RELAP5-3D models were used to simulate an exponential decrease in pressure over a 20 second period. The results of this loss of coolant analysis indicate that heat is initially transferred from the primary loop to the secondary loop, but after the decrease in pressure in the primary loop the heat is transferred from the secondary loop to the primary loop. A high-temperature gas reactor model should be developed and connected to the heat transfer component to simulate other transients.

  2. Technical Subtopic 2.1: Modeling Variable Refrigerant Flow Heat Pump and Heat Recovery Equipment in EnergyPlus

    SciTech Connect (OSTI)

    Raustad, Richard; Nigusse, Bereket; Domitrovic, Ron

    2013-09-30T23:59:59.000Z

    The University of Central Florida/Florida Solar Energy Center, in cooperation with the Electric Power Research Institute and several variable-refrigerant-flow heat pump (VRF HP) manufacturers, provided a detailed computer model for a VRF HP system in the United States Department of Energy's (U.S. DOE) EnergyPlus? building energy simulation tool. Detailed laboratory testing and field demonstrations were performed to measure equipment performance and compare this performance to both the manufacturer's data and that predicted by the use of this new model through computer simulation. The project goal was to investigate the complex interactions of VRF HP systems from an HVAC system perspective, and explore the operational characteristics of this HVAC system type within a laboratory and real world building environment. Detailed laboratory testing of this advanced HVAC system provided invaluable performance information which does not currently exist in the form required for proper analysis and modeling. This information will also be useful for developing and/or supporting test standards for VRF HP systems. Field testing VRF HP systems also provided performance and operational information pertaining to installation, system configuration, and operational controls. Information collected from both laboratory and field tests were then used to create and validate the VRF HP system computer model which, in turn, provides architects, engineers, and building owners the confidence necessary to accurately and reliably perform building energy simulations. This new VRF HP model is available in the current public release version of DOE?s EnergyPlus software and can be used to investigate building energy use in both new and existing building stock. The general laboratory testing did not use the AHRI Standard 1230 test procedure and instead used an approach designed to measure the field installed full-load operating performance. This projects test methodology used the air enthalpy method where relevant air-side parameters were controlled while collecting output performance data at discreet points of steady-state operation. The primary metrics include system power consumption and zonal heating and cooling capacity. Using this test method, the measured total cooling capacity was somewhat lower than reported by the manufacturer. The measured power was found to be equal to or greater than the manufacturers indicated power. Heating capacity measurements produced similar results. The air-side performance metric was total cooling and heating energy since the computer model uses those same metrics as input to the model. Although the sensible and latent components of total cooling were measured, they are not described in this report. The test methodology set the thermostat set point temperature very low for cooling and very high for heating to measure full-load performance and was originally thought to provide the maximum available capacity. Manufacturers stated that this test method would not accurately measure performance of VRF systems which is now believed to be a true statement. Near the end of the project, an alternate test method was developed to better represent VRF system performance as if field installed. This method of test is preliminarily called the Load Based Method of Test where the load is fixed and the indoor conditions and unit operation are allowed to fluctuate. This test method was only briefly attempted in a laboratory setting but does show promise for future lab testing. Since variable-speed air-conditioners and heat pumps include an on-board control algorithm to modulate capacity, these systems are difficult to test. Manufacturers do have the ability to override internal components to accommodate certification procedures, however, it is unknown if the resulting operation is replicated in the field, or if so, how often. Other studies have shown that variable-speed air-conditioners and heat pumps do out perform their single-speed counterparts though these field studies leave as many questions as they do provide answers. The measure

  3. Loss of feed flow, steam generator tube rupture and steam line break thermohydraulic experiments

    SciTech Connect (OSTI)

    Mendler, O J; Takeuchi, K; Young, M Y

    1986-10-01T23:59:59.000Z

    The Westinghouse Model Boiler No. 2 (MB-2) steam generator test model at the Engineering Test Facility in Tampa, Florida, was reinstrumented and modified for performing a series of tests simulating steam generator accident transients. The transients simulated were: loss of feed flow, steam generator tube rupture, and steam line break events. This document presents a description of (1) the model boiler and the associated test facility, (2) the tests performed, and (3) the analyses of the test results.

  4. A parametric study of shock jump chemistry, electron temperature, and radiative heat transfer models in hypersonic flows

    E-Print Network [OSTI]

    Greendyke, Robert Brian

    1988-01-01T23:59:59.000Z

    A PARAMETRIC STUDY OF SHOCK JUMP CHEMISTRY, ELECTRON TEMPERATURE, AND RADIATIVE HEAT TRANSFER MODELS IN HYPERSONIC FLOWS A Thesis by ROBERT BRIAN GREENDYKE Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 1988 Major Subject: Aerospace Engineering A PARAMETRIC STUDY OF SHOCK JUMP CHEMISTRY, ELECTRON TEMPERATURE, AND RADIATIVE HEAT TRANSFER MODELS IN HYPERSONIC FLOWS A Thesis by ROBERT BRIAN...

  5. A comparison of analog methods in heat flow analysis with simplified mathematica methods as applied to flight structures

    E-Print Network [OSTI]

    Murray, William

    1960-01-01T23:59:59.000Z

    in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE January 1960 Maj or Subj ect: Mechanical Engineering A COMPARISON OF ANALOG METHODS IN HEAT FLOW ANALYSIS WITH SIMPLIFIED MATHEMATICAL METHODS AS APPLIED TO FLIGHT STRUCTURES... and require lengthy and sometimes difficult mathematical computations to arrive at a solution. It is obvious that there is a need for a simple, rapid, and reliable method of solving complex problems involving heat flow. It is the purpose...

  6. A mathematical basis for automated structured grid generation with close coupling to the flow solver

    SciTech Connect (OSTI)

    Barnette, D.W.

    1998-02-01T23:59:59.000Z

    The first two truncation error terms resulting from finite differencing the convection terms in the two-dimensional Navier-Stokes equations are examined for the purpose of constructing two-dimensional grid generation schemes. These schemes are constructed such that the resulting grid distributions drive the error terms to zero. Two sets of equations result, one for each error term, that show promise in generating grids that provide more accurate flow solutions and possibly faster convergence. One set results in an algebraic scheme that drives the first truncation term to zero, and the other a hyperbolic scheme that drives the second term to zero. Also discussed is the possibility of using the schemes in sequentially constructing a grid in an iterative algorithm involving the flow solver. In essence, the process is envisioned to generate not only a flow field solution but the grid as well, rendering the approach a hands-off method for grid generation

  7. Electron Heating by the Ion Cyclotron Instability in Collisionless Accretion Flows. II. Electron Heating Efficiency as a Function of Flow Conditions

    E-Print Network [OSTI]

    Sironi, Lorenzo

    2014-01-01T23:59:59.000Z

    In the innermost regions of low-luminosity accretion flows, including Sgr A* at the center of our Galaxy, the frequency of Coulomb collisions is so low that the plasma is two-temperature, with the ions substantially hotter than the electrons. This paradigm assumes that Coulomb collisions are the only channel for transferring the ion energy to the electrons. In this work, the second of a series, we assess the efficiency of electron heating by ion velocity-space instabilities in collisionless accretion flows. The instabilities are seeded by the pressure anisotropy induced by magnetic field amplification, coupled to the adiabatic invariance of the particle magnetic moments. Using two-dimensional (2D) particle-in-cell (PIC) simulations, we showed in Paper I that if the electron-to-ion temperature ratio is < 0.2, the ion cyclotron instability is the dominant mode for values of ion beta_i ~ 5-30 (here, beta_i is the ratio of ion thermal pressure to magnetic pressure), as appropriate for the midplane of low-lumin...

  8. A comparative study on a non-linear turbulent heat transfer model for separating and reattaching flows

    SciTech Connect (OSTI)

    Jia, S.; Chung, B.T.F. [Univ. of Akron, OH (United States). Dept. of Mechanical Engineering

    1996-12-31T23:59:59.000Z

    Based on a previously proposed non-linear turbulence model, a turbulent heat transfer model is formulated in the present study using the concept of Generalized Gradient Diffusion (GGD) hypothesis. Under this hypothesis, an anisotropic thermal diffusivity can be obtained through the proposed non-linear turbulent model which is applied to the turbulent flow and heat transfer in a sudden expansion pipe with a constant heat flux through the pipe wall. The numerical results are compared with the available experimental data for both turbulent and thermal quantities, with an emphasis on the non-linear heat transfer predictions. The improved results are obtained for the bulk temperature distribution showing that the present non-linear heat transfer model is capable of predicting the anisotropic turbulent heat transfer for the pipe expansion flow. Some limits of the proposed model are also identified and discussed.

  9. Assessment of the possibilities of electricity and heat co-generation from biomass in Romania's case

    SciTech Connect (OSTI)

    Matei, M.

    1998-07-01T23:59:59.000Z

    This paper examines the use of biomass for electricity (and heat) production. The objectives of the works developed by RENEL--GSCI were to determine the Romanian potential biomass resources available in economic conditions for electricity production from biomass, to review the routes and the available equipment for power generation from biomass, to carry out a techno-economic assessment of different systems for electricity production from biomass, to identify the most suitable system for electricity and heat cogeneration from biomass, to carry out a detailed techno-economic assessment of the selected system, to perform an environmental impact assessment of the selected system and to propose a demonstration project. RENEL--GSCI (former ICEMENERG) has carried out an assessment concerning Romania's biomass potential taking into account the forestry and wood processing wastes (in the near term) and agricultural wastes (in mid term) as well as managing plantations (in the long term). Comparative techno-economical evaluation of biomass based systems for decentralized power generation was made. The cost analysis of electricity produced from biomass has indicated that the system based on boiler and steam turbine of 2,000 kW running on wood-wastes is the most economical. A location for a demonstration project with low cost financing possibilities and maximum benefits was searched. To mitigate the electricity cost it was necessary to find a location in which the fuel price is quite low, so that the low yield of small installation can be balanced. In order to demonstrate the performances of a system which uses biomass for electricity and heat generation, a pulp and paper mill which needed electricity and heat, and, had large amount of wood wastes from industrial process was found as the most suitable location. A technical and economical analysis for 8 systems for electricity production from bark and wood waste was performed.

  10. Advanced Soldier Thermoelectric Power System for Power Generation from Battlefield Heat Sources

    SciTech Connect (OSTI)

    Hendricks, Terry J.; Hogan, Tim; Case, Eldon D.; Cauchy, Charles J.

    2010-09-01T23:59:59.000Z

    The U.S. military uses large amounts of fuel during deployments and battlefield operations. This project sought to develop a lightweight, small form-factor, soldier-portable advanced thermoelectric (TE) system prototype to recover and convert waste heat from various deployed military equipment (i.e., diesel generators/engines, incinerators, vehicles, and potentially mobile kitchens), with the ultimate purpose of producing power for soldier battery charging, advanced capacitor charging, and other battlefield power applications. The technical approach employed microchannel technology, a unique ďpower panelĒ approach to heat exchange/TE system integration, and newly-characterized LAST (lead-antimony-silver-telluride) and LASTT (lead-antimony-silver-tin-telluride) TE materials segmented with bismuth telluride TE materials in designing a segmented-element TE power module and system. This project researched never-before-addressed system integration challenges (thermal expansion, thermal diffusion, electrical interconnection, thermal and electrical interfaces) of designing thin ďpower panelsĒ consisting of alternating layers of thin, microchannel heat exchangers (hot and cold) sandwiching thin, segmented-element TE power generators. The TE properties, structurally properties, and thermal fatigue behavior of LAST and LASTT materials were developed and characterized such that the first segmented-element TE modules using LAST / LASTT materials were fabricated and tested at hot-side temperatures = 400 įC and cold-side temperatures = 40 įC. LAST / LASTT materials were successfully segmented with bismuth telluride and electrically interconnected with diffusion barrier materials and copper strapping within the module electrical circuit. A TE system design was developed to produce 1.5-1.6 kW of electrical energy using these new TE modules from the exhaust waste heat of 60-kW Tactical Quiet Generators as demonstration vehicles.

  11. Convective heat transfer to CO{sub 2} at a supercritical pressure flowing vertically upward in tubes and an annular channel

    SciTech Connect (OSTI)

    Bae, Yoon-Yeong; Kim, Hwan-Yeol [Korea Atomic Energy Research Institute, 1045 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea)

    2009-01-15T23:59:59.000Z

    The Super-Critical Water-Cooled Reactor (SCWR) has been chosen by the Generation IV International Forum as one of the candidates for the next generation nuclear reactors. Heat transfer to water from a fuel assembly may deteriorate at certain supercritical pressure flow conditions and its estimation at degraded conditions as well as in normal conditions is very important to the design of a safe and reliable reactor core. Extensive experiments on a heat transfer to a vertically upward flowing CO{sub 2} at a supercritical pressure in tubes and an annular channel have been performed. The geometries of the test sections include tubes of an internal diameter (ID) of 4.4 and 9.0 mm and an annular channel (8 x 10 mm). The heat transfer coefficient (HTC) and Nusselt numbers were derived from the inner wall temperature converted by using the outer wall temperature measured by adhesive K-type thermocouples and a direct (tube) or indirect (annular channel) electric heating power. From the test results, a correlation, which covers both a deteriorated and a normal heat transfer regime, was developed. The developed correlation takes different forms in each interval divided by the value of parameter Bu. The parameter Bu (referred to as Bu hereafter), a function of the Grashof number, the Reynolds number and the Prandtl number, was introduced since it is known to be a controlling factor for the occurrence of a heat transfer deterioration due to a buoyancy effect. The developed correlation predicted the HTCs for water and HCFC-22 fairly well. (author)

  12. Three-dimensional instabilities in a discretely heated annular flow: Onset of spatio-temporal complexity via defect dynamics

    E-Print Network [OSTI]

    Marques, Francisco

    . INTRODUCTION Interest in natural convection in enclosures has a long history,1 motivated by both relevanceThree-dimensional instabilities in a discretely heated annular flow: Onset of spatio- temporal of the flow in an annular rotor-stator cavity Phys. Fluids 21, 064106 (2009); 10.1063/1.3156859 Stability

  13. A Parallel Implementation of the TOUGH2 Software Package for Large Scale Multiphase Fluid and Heat Flow Simulations

    E-Print Network [OSTI]

    Elmroth, Erik

    A Parallel Implementation of the TOUGH2 Software Package for Large Scale Multiphase Fluid and Heat groundwater flow related problems such as nuclear waste isolation, environmental remediation, and geothermal with Ę°§£¶•ß ®°© blocks in a Yucca Mountain nuclear waste site study. Keywords. Ground water flow, grid partitioning

  14. A Parallel Implementation of the TOUGH2 Software Package for Large Scale Multiphase Fluid and Heat Flow Simulations

    E-Print Network [OSTI]

    Elmroth, Erik

    A Parallel Implementation of the TOUGH2 Software Package for Large Scale Multiphase Fluid and Heat groundwater flow related problems such as nuclear waste isolation, environmental remediation, and geothermal 6 blocks in a Yucca Mountain nuclear waste site study. Keywords. Ground water flow, grid

  15. A review and development of correlations for base pressure and base heating in supersonic flow

    SciTech Connect (OSTI)

    Lamb, J.P. [Texas Univ., Austin, TX (United States). Dept. of Mechanical Engineering; Oberkampf, W.L. [Sandia National Labs., Albuquerque, NM (United States)

    1993-11-01T23:59:59.000Z

    A comprehensive review of experimental base pressure and base heating data related to supersonic and hypersonic flight vehicles has been completed. Particular attention was paid to free-flight data as well as wind tunnel data for models without rear sting support. Using theoretically based correlation parameters, a series of internally consistent, empirical prediction equations has been developed for planar and axisymmetric geometries (wedges, cones, and cylinders). These equations encompass the speed range from low supersonic to hypersonic flow and laminar and turbulent forebody boundary layers. A wide range of cone and wedge angles and cone bluntness ratios was included in the data base used to develop the correlations. The present investigation also included preliminary studies of the effect of angle of attack and specific-heat ratio of the gas.

  16. Heat transfer and material flow during laser assisted multi-layer additive manufacturing

    SciTech Connect (OSTI)

    Manvatkar, V.; De, A.; DebRoy, T. [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

    2014-09-28T23:59:59.000Z

    A three-dimensional, transient, heat transfer, and fluid flow model is developed for the laser assisted multilayer additive manufacturing process with coaxially fed austenitic stainless steel powder. Heat transfer between the laser beam and the powder particles is considered both during their flight between the nozzle and the growth surface and after they deposit on the surface. The geometry of the build layer obtained from independent experiments is compared with that obtained from the model. The spatial variation of melt geometry, cooling rate, and peak temperatures is examined in various layers. The computed cooling rates and solidification parameters are used to estimate the cell spacings and hardness in various layers of the structure. Good agreement is achieved between the computed geometry, cell spacings, and hardness with the corresponding independent experimental results.

  17. An experimental study of endwall heat transfer enhancement for flow past staggered non-conducting pin fin arrays

    E-Print Network [OSTI]

    Achanta, Vamsee Satish

    2004-09-30T23:59:59.000Z

    of Technology, Madras, India Chair of Advisory Committee: Sai C. Lau In this work, we analyzed the enhanced heat transfer from the endwall for flow past pin fin arrays. The aim is to resolve the controversy over the heat transfer that is taking place from... AN EXPERIMENTAL STUDY OF ENDWALL HEAT TRANSFER ENHANCEMENT FOR FLOW PAST STAGGERED NON-CONDUCTING PIN FIN ARRAYS A Thesis by VAMSEE SATISH ACHANTA Submitted to the Office of Graduate Studies of Texas A&M University in partial...

  18. Reduced heat flow in light water (H2O) due to heavy water (D2O)

    E-Print Network [OSTI]

    William R. Gorman; James D. Brownridge

    2008-09-04T23:59:59.000Z

    The flow of heat, from top to bottom, in a column of light water can be decreased by over 1000% with the addition of heavy water. A column of light water cools from 25 C to 0 C in 11 hours, however, with the addition of heavy water it takes more than 100 hours. There is a concentration dependence where the cooling time increases as the concentration of added (D2O) increases, with a near maximum being reached with as little as 2% of (D2O) added. This phenomenon will not occur if the water is mixed after the heavy water is added.

  19. The flow and heat transfer in a viscous fluid over an unsteady stretching surface

    E-Print Network [OSTI]

    Ene, Remus-Daniel; Marinca, Bogdan

    2015-01-01T23:59:59.000Z

    In this paper we have studied the flow and heat transfer in a viscous fluid by a horizontal sheet. The stretching rate and temperature of the sheet vary with time. The governing equations for momentum and thermal energy are reduced to ordinary differential equations by means of similarity transformation. These equations are solved approximately by means of the Optimal Homotopy Asymptotic Method (OHAM) which provides us with a convenient way to control the convergence of approximation solutions and adjust convergence rigorous when necessary. Some examples are given and the results obtained reveal that the proposed method is effective and easy to use.

  20. Parallel heat flux and flow acceleration in open field line plasmas with magnetic trapping

    SciTech Connect (OSTI)

    Guo, Zehua; Tang, Xian-Zhu; McDevitt, Chris [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-10-15T23:59:59.000Z

    The magnetic field strength modulation in a tokamak scrape-off layer (SOL) provides both flux expansion next to the divertor plates and magnetic trapping in a large portion of the SOL. Previously, we have focused on a flux expander with long mean-free-path, motivated by the high temperature and low density edge anticipated for an absorbing boundary enabled by liquid lithium surfaces. Here, the effects of magnetic trapping and a marginal collisionality on parallel heat flux and parallel flow acceleration are examined. The various transport mechanisms are captured by kinetic simulations in a simple but representative mirror-expander geometry. The observed parallel flow acceleration is interpreted and elucidated with a modified Chew-Goldberger-Low model that retains temperature anisotropy and finite collisionality.

  1. EIS-0302: Transfer of the Heat Source/Radioisotope Thermoelectric Generator Assembly and Test Operations From the Mound Site

    Broader source: Energy.gov [DOE]

    This EIS analyzes DOE's proposed transfer of the Heat Source/Radioisotope Thermoelectric Generator (HS/RTG) operations at the Mound Site near Miamisburg, Ohio, to an alternative DOE site.

  2. High-power ELF radiation generated by modulated HF heating of the ionosphere can cause Earthquakes, Cyclones and localized heating

    E-Print Network [OSTI]

    Paris-Sud XI, Universitť de

    transmitter radiates a strong beam of high- frequency (HF) waves modulated at ELF. This HF heating modulates-frequency (HF) radiation in the megahertz range [7]. This heating modulates the electron's temperature in the D

  3. The Streaming Potential Generated by Flow of Wet Steam in Capillary Tubes

    SciTech Connect (OSTI)

    Marsden, S.S. Jr.; Tyran, Craig K.

    1986-01-21T23:59:59.000Z

    For a constant pressure differential, the flow of wet steam generated electric potentials which increased with time and did not reach equilibrium values. These potentials were found to increase to values greater than 100 volts. The reason for this kind of potential build-up behavior was the presence of tiny flowing water slugs which were interspersed with electrically nonconductive steam vapor slugs. The measured electric potential for wet steam increased with pressure differential, but the relationship was not linear. The increase in potential with pressure drop was attributed both to an increase in fluid flow rate and changes in the wet steam quality.

  4. Asymptotic approximations for the sound generated by aerofoils in unsteady subsonic flows

    E-Print Network [OSTI]

    Ayton, Lorna Jane

    2014-10-07T23:59:59.000Z

    is later relaxed and we investigate the sound generated by high-frequency gust-aerofoil interactions in steady shear flows. Throughout all of the aforementioned work, the key process involves identifying various asymptotic regions around the aerofoil where... review of the different mechanisms generating noise within the engine, including perhaps principally the jet and (the subject of this thesis) the interaction of the vortical wakes shed from a rotor blade row with a down- stream stator blade row; a...

  5. MODELING COUPLED PROCESSES OF MULTIPHASE FLOW AND HEAT TRANSFER IN UNSATURATED FRACTURED ROCK

    SciTech Connect (OSTI)

    Y. Wu; S. Mukhopadhyay; K. Zhang; G.S. Bodvarsson

    2006-02-28T23:59:59.000Z

    A mountain-scale, thermal-hydrologic (TH) numerical model is developed for investigating unsaturated flow behavior in response to decay heat from the radioactive waste repository at Yucca Mountain, Nevada, USA. The TH model, consisting of three-dimensional (3-D) representations of the unsaturated zone, is based on the current repository design, drift layout, and thermal loading scenario under estimated current and future climate conditions. More specifically, the TH model implements the current geological framework and hydrogeological conceptual models, and incorporates the most updated, best-estimated input parameters. This mountain-scale TH model simulates the coupled TH processes related to mountain-scale multiphase fluid flow, and evaluates the impact of radioactive waste heat on the hydrogeological system, including thermally perturbed liquid saturation, gas- and liquid-phase fluxes, and water and rock temperature elevations, as well as the changes in water flux driven by evaporation/condensation processes and drainage between drifts. For a better description of the ambient geothermal condition of the unsaturated zone system, the TH model is first calibrated against measured borehole temperature data. The ambient temperature calibration provides the necessary surface and water table boundary as well as initial conditions. Then, the TH model is used to obtain scientific understanding of TH processes in the Yucca Mountain unsaturated zone under the designed schedule of repository thermal load.

  6. Heat Flow and Gas Hydrates on the Continental Margin of India: Building on Results from NGHP Expedition 01

    SciTech Connect (OSTI)

    Anne Trehu; Peter Kannberg

    2011-06-30T23:59:59.000Z

    The Indian National Gas Hydrate Program (NGHP) Expedition 01 presented the unique opportunity to constrain regional heat flow derived from seismic observations by using drilling data in three regions on the continental margin of India. The seismic bottom simulating reflection (BSR) is a well-documented feature in hydrate bearing sediments, and can serve as a proxy for apparent heat flow if data are available to estimate acoustic velocity and density in water and sediments, thermal conductivity, and seafloor temperature. Direct observations of temperature at depth and physical properties of the sediment obtained from drilling can be used to calibrate the seismic observations, decreasing the uncertainty of the seismically-derived estimates. Anomalies in apparent heat flow can result from a variety of sources, including sedimentation, erosion, topographic refraction and fluid flow. We constructed apparent heat flow maps for portions of the Krishna-Godavari (K-G) basin, the Mahanadi basin, and the Andaman basin and modeled anomalies using 1-D conductive thermal models. Apparent heat flow values in the Krishna-Godavari (K-G) basin and Mahanadi basin are generally 0.035 to 0.055 watts per square meter (W/m{sup 2}). The borehole data show an increase in apparent heat flow as water depth increases from 900 to 1500 m. In the SW part of the seismic grid, 1D modeling of the effect of sedimentation on heat flow shows that {approx}50% of the observed increase in apparent heat flow with increasing water depth can be attributed to trapping of sediments behind a 'toe-thrust' ridge that is forming along the seaward edge of a thick, rapidly accumulating deltaic sediment pile. The remainder of the anomaly can be explained either by a decrease in thermal conductivity of the sediments filling the slope basin or by lateral advection of heat through fluid flow along stratigraphic horizons within the basin and through flexural faults in the crest of the anticline. Such flow probably plays a role in bringing methane into the ridge formed by the toe-thrust. Because of the small anomaly due to this process and the uncertainty in thermal conductivity, we did not model this process explicitly. In the NE part of the K-G basin seismic grid, a number of local heat flow lows and highs are observed, which can be attributed to topographic refraction and to local fluid flow along faults, respectively. No regional anomaly can be resolved. Because of lack of continuity between the K-G basin sites within the seismic grid and those {approx}70 km to the NE in water depths of 1200 to 1500 m, we do not speculate on the reason for higher heat flow at these depths. The Mahanadi basin results, while limited in geographic extent, are similar to those for the K-G basin. The Andaman basin exhibits much lower apparent heat flow values, ranging from 0.015 to 0.025 W/m{sup 2}. Heat flow here also appears to increase with increasing water depth. The very low heat flow here is among the lowest heat flow observed anywhere and gives rise to a very thick hydrate stability zone in the sediments. Through 1D models of sedimentation (with extremely high sedimentation rates as a proxy for tectonic thickening), we concluded that the very low heat flow can probably be attributed to the combined effects of high sedimentation rate, low thermal conductivity, tectonic thickening of sediments and the cooling effect of a subducting plate in a subduction zone forearc. Like for the K-G basin, much of the local variability can be attributed to topography. The regional increase in heat flow with water depth remains unexplained because the seismic grid available to us did not extend far enough to define the local tectonic setting of the slope basin controlling this observational pattern. The results are compared to results from other margins, both active and passive. While an increase in apparent heat flow with increasing water depth is widely observed, it is likely a result of different processes in different places. The very low heat flow due to sedimentation and tectonics in the Andaman basi

  7. Heat Flow and Gas Hydrates on the Continental Margin of India: Building on Results from NGHP Expedition 01

    SciTech Connect (OSTI)

    Trehu, Anne; Kannberg, Peter

    2011-06-30T23:59:59.000Z

    The Indian National Gas Hydrate Program (NGHP) Expedition 01 presented the unique opportunity to constrain regional heat flow derived from seismic observations by using drilling data in three regions on the continental margin of India. The seismic bottom simulating reflection (BSR) is a well-documented feature in hydrate bearing sediments, and can serve as a proxy for apparent heat flow if data are available to estimate acoustic velocity and density in water and sediments, thermal conductivity, and seafloor temperature. Direct observations of temperature at depth and physical properties of the sediment obtained from drilling can be used to calibrate the seismic observations, decreasing the uncertainty of the seismically-derived estimates. Anomalies in apparent heat flow can result from a variety of sources, including sedimentation, erosion, topographic refraction and fluid flow. We constructed apparent heat flow maps for portions of the Krishna-Godavari (K-G) basin, the Mahanadi basin, and the Andaman basin and modeled anomalies using 1-D conductive thermal models. Apparent heat flow values in the Krishna-Godavari (K-G) basin and Mahanadi basin are generally 0.035 to 0.055 watts per square meter (W/m2). The borehole data show an increase in apparent heat flow as water depth increases from 900 to 1500 m. In the SW part of the seismic grid, 1D modeling of the effect of sedimentation on heat flow shows that ~50% of the observed increase in apparent heat flow with increasing water depth can be attributed to trapping of sediments behind a "toe-thrust" ridge that is forming along the seaward edge of a thick, rapidly accumulating deltaic sediment pile. The remainder of the anomaly can be explained either by a decrease in thermal conductivity of the sediments filling the slope basin or by lateral advection of heat through fluid flow along stratigraphic horizons within the basin and through flexural faults in the crest of the anticline. Such flow probably plays a role in bringing methane into the ridge formed by the toe-thrust. Because of the small anomaly due to this process and the uncertainty in thermal conductivity, we did not model this process explicitly. In the NE part of the K-G basin seismic grid, a number of local heat flow lows and highs are observed, which can be attributed to topographic refraction and to local fluid flow along faults, respectively. No regional anomaly can be resolved. Because of lack of continuity between the K-G basin sites within the seismic grid and those ~70 km to the NE in water depths of 1200 to 1500 m, we do not speculate on the reason for higher heat flow at these depths. The Mahanadi basin results, while limited in geographic extent, are similar to those for the KG basin. The Andaman basin exhibits much lower apparent heat flow values, ranging from 0.015 to 0.025 W/m2. Heat flow here also appears to increase with increasing water depth. The very low heat flow here is among the lowest heat flow observed anywhere and gives rise to a very thick hydrate stability zone in the sediments. Through 1D models of sedimentation (with extremely high sedimentation rates as a proxy for tectonic thickening), we concluded that the very low heat flow can probably be attributed to the combined effects of high sedimentation rate, low thermal conductivity, tectonic thickening of sediments and the cooling effect of a subducting plate in a subduction zone forearc. Like for the K-G basin, much of the local variability can be attributed to topography. The regional increase in heat flow with water depth remains unexplained because the seismic grid available to us did not extend far enough to define the local tectonic setting of the slope basin controlling this observational pattern. The results are compared to results from other margins, both active and passive. While an increase in apparent heat flow with increasing water depth is widely observed, it is likely a result of different processes in different places. The very low heat flow due to sedimentation and tectonics in the Andaman basin is at the low end of glob

  8. Next Generation Nuclear Plant Phenomena Identification and Ranking Tables (PIRTs) Volume 6: Process Heat and Hydrogen Co-Generation PIRTs

    SciTech Connect (OSTI)

    Forsberg, Charles W [ORNL; Gorensek, M. B. [Savannah River National Laboratory (SRNL); Herring, S. [Idaho National Laboratory (INL); Pickard, P. [Sandia National Laboratories (SNL)

    2008-03-01T23:59:59.000Z

    A Phenomena Identification and Ranking Table (PIRT) exercise was conducted to identify potential safety-0-related physical phenomena for the Next Generation Nuclear Plant (NGNP) when coupled to a hydrogen production or similar chemical plant. The NGNP is a very high-temperature reactor (VHTR) with the design goal to produce high-temperature heat and electricity for nearby chemical plants. Because high-temperature heat can only be transported limited distances, the two plants will be close to each other. One of the primary applications for the VHTR would be to supply heat and electricity for the production of hydrogen. There was no assessment of chemical plant safety challenges. The primary application of this PIRT is to support the safety analysis of the NGNP coupled one or more small hydrogen production pilot plants. However, the chemical plant processes to be coupled to the NGNP have not yet been chosen; thus, a broad PIRT assessment was conducted to scope alternative potential applications and test facilities associated with the NGNP. The hazards associated with various chemicals and methods to minimize risks from those hazards are well understood within the chemical industry. Much but not all of the information required to assure safe conditions (separation distance, relative elevation, berms) is known for a reactor coupled to a chemical plant. There is also some experience with nuclear plants in several countries that have produced steam for industrial applications. The specific characteristics of the chemical plant, site layout, and the maximum stored inventories of chemicals can provide the starting point for the safety assessments. While the panel identified events and phenomena of safety significance, there is one added caveat. Multiple high-temperature reactors provide safety-related experience and understanding of reactor safety. In contrast, there have been only limited safety studies of coupled chemical and nuclear plants. The work herein provides a starting point for those studies; but, the general level of understanding of safety in coupling nuclear and chemical plants is less than in other areas of high-temperature reactor safety.

  9. Heat transfer characteristics of R410A-oil mixture flow boiling inside a 7 mm straight smooth tube

    SciTech Connect (OSTI)

    Hu, Haitao; Ding, Guoliang; Wei, Wenjian; Wang, Zhence [Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai 200240 (China); Wang, Kaijian [Fujitsu General Institute of Air-Conditioning Technology Limited, Kawasaki 213-8502 (Japan)

    2008-01-15T23:59:59.000Z

    Two-phase flow patterns and heat transfer characteristics of R410A-oil mixture flow boiling inside a straight smooth tube with the outside diameter of 7.0 mm were investigated experimentally. The experimental conditions include the evaporation temperature of 5 C, the mass flux from 200 to 400 kg m{sup -2} s{sup -1}, the heat flux from 7.56 to 15.12 kW m{sup -2}, the inlet vapor quality from 0.2 to 0.7, nominal oil concentration from 0% to 5%. The test results show that the heat transfer coefficient of R410A-oil mixture increases with mass flux of refrigerant-oil mixture; the presence of oil enhances the heat transfer at the range of low and intermediate vapor qualities; there is a peak of local heat transfer coefficient at about 2-4% nominal oil concentration at higher vapor qualities, and the peak shifts to lower nominal oil concentration with the increasing of vapor qualities; higher nominal oil concentration gives more detrimental effect at high vapor qualities. The flow pattern map of R410A-oil mixture was developed based on refrigerant-oil mixture properties, and the observed flow patterns match well with the flow pattern map. New correlation to predict the local heat transfer of R410A-oil mixture flow boiling inside the straight smooth tube was developed based on flow patterns and local properties of refrigerant-oil mixture, and it agrees with 90% of the experiment data within the deviation of {+-}25%. (author)

  10. Study for radionuclide transfer ratio of aerosols generated during heat cutting

    SciTech Connect (OSTI)

    Iguchi, Yukihiro; Baba, Tsutomu; Kawakami, Hiroto [Japan Nuclear Energy Safety Organization - JNES (Japan); Kitahara, Takashi; Watanabe, Atsushi [Hitachi, Ltd. (Japan); Kodama, Mitsuhiro [Nippon Nuclear Fuel Development Co., Ltd. (Japan)

    2007-07-01T23:59:59.000Z

    The metallic elements with a low melting point and high vapor pressure seemed to transfer in aerosols selectively at dismantling reactor internals using heat cutting. Therefore, the arc melting tests of neutron irradiated zirconium alloy were conducted to investigate the radionuclide transfer behavior of aerosols generated during the heat cutting of activated metals. The arc melting test was conducted using a tungsten inert gas welding machine in an inert gas or air atmosphere. The radioactive aerosols were collected by filter and charcoal filter. The test sample was obtained from Zry-2 fuel cladding irradiated in a Japanese boiling water reactor for five fuel cycles. The activity analysis, chemical composition measurement and scanning electron microscope observation of aerosols were carried out. Some radionuclides were enriched in the aerosols generated in an inert gas atmosphere and the radionuclide transfer ratio did not change remarkably by the presence of air. The transfer ratio of Sb-125 was almost the same as that of Co-60. It was expected that Sb-125 was enriched from other elements since Sb is an element with a low melting point and high vapor pressure compared with the base metal (Zr). In the viewpoint of the environmental impact assessment, it became clear that the influence if Sb-125 is comparable to Co-60. The transfer ratio of Mn-54 was one order higher compared with other radionuclides. The results were discussed on the basis of thermal properties and oxide formation energy of the metallic elements. (authors)

  11. On-Line Monitoring and Diagnostics of the Integrity of Nuclear Plant Steam Generators and Heat Exchangers.

    SciTech Connect (OSTI)

    Belle R. Upadhyaya; J. Wesley Hines

    2004-09-27T23:59:59.000Z

    The overall purpose of this Nuclear Engineering Education Research (NEER) project was to integrate new, innovative, and existing technologies to develop a fault diagnostics and characterization system for nuclear plant steam generators (SG) and heat exchangers (HX). Issues related to system level degradation of SG and HX tubing, including tube fouling, performance under reduced heat transfer area, and the damage caused by stress corrosion cracking, are the important factors that influence overall plant operation, maintenance, and economic viability of nuclear power systems. The research at The University of Tennessee focused on the development of techniques for monitoring process and structural integrity of steam generators and heat exchangers. The objectives of the project were accomplished by the completion of the following tasks. All the objectives were accomplished during the project period. This report summarizes the research and development activities, results, and accomplishments during June 2001-September 2004. (1) Development and testing of a high-fidelity nodal model of a U-tube steam generator (UTSG) to simulate the effects of fouling and to generate a database representing normal and degraded process conditions. Application of the group method of data handling (GMDH) method for process variable prediction. (2) Development of a laboratory test module to simulate particulate fouling of HX tubes and its effect on overall thermal resistance. Application of the GMDH technique to predict HX fluid temperatures, and to compare with the calculated thermal resistance. (3) Development of a hybrid modeling technique for process diagnosis and its evaluation using laboratory heat exchanger test data. (4) Development and testing of a sensor suite using piezo-electric devices for monitoring structural integrity of both flat plates (beams) and tubing. Experiments were performed in air, and in water with and without bubbly flow. (5) Development of advanced signal processing methods using wavelet transforms and image processing techniques for isolating flaw types. (6) Development and implementation of a new nonlinear and non-stationary signal processing method, called the Hilbert-Huang transform (HHT), for flaw detection and location. This is a more robust and adaptive approach compared to the wavelet transform. (7) Implementation of a moving-window technique in the time domain for detecting and quantifying flaw types in tubular structures. A window zooming technique was also developed for flaw location in tubes. (8) Theoretical study of elastic wave propagation (longitudinal and shear waves) in metallic flat plates and tubing with and without flaws. (9) Simulation of the Lamb wave propagation using the finite-element code ABAQUS. This enabled the verification of the experimental results. The research tasks included both analytical research and experimental studies. The experimental results helped to enhance the robustness of fault monitoring methods and to provide a systematic verification of the analytical results. The results of this research were disseminated in scientific meetings. A journal manuscript was submitted for publication. The new findings of this research have potential applications in aerospace and civil structures. The report contains a complete bibliography that was developed during the course of the project.

  12. On-Line Monitoring and Diagnostics of the Integrity of Nuclear Plant Steam Generators and Heat Exchangers, Volumes 1, 2.

    SciTech Connect (OSTI)

    Upadhyaya, Belle R.; Hines, J. Wesley; Lu, Baofu; Huang, Xuedong; Penha, Rosani, L.; Perillo, Sergio, R.; Zhao, Ke

    2005-06-03T23:59:59.000Z

    The overall purpose of this Nuclear Engineering Education Research (NEER) project was to integrate new, innovative, and existing technologies to develop a fault diagnostics and characterization system for nuclear plant steam generators (SG) and heat exchangers (HX). Issues related to system level degradation of SG and HX tubing, including tube fouling, performance under reduced heat transfer area, and the damage caused by stress corrosion cracking, are the important factors that influence overall plant operation, maintenance, and economic viability of nuclear power systems. The research at The University of Tennessee focused on the development of techniques for monitoring process and structural integrity of steam generators and heat exchangers. The objectives of the project were accomplished by the completion of the following tasks. All the objectives were accomplished during the project period. This report summarizes the research and development activities, results, and accomplishments during June 2001 √?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬? September 2004. √?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬∑ Development and testing of a high-fidelity nodal model of a U-tube steam generator (UTSG) to simulate the effects of fouling and to generate a database representing normal and degraded process conditions. Application of the group method of data handling (GMDH) method for process variable prediction. √?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬∑ Development of a laboratory test module to simulate particulate fouling of HX tubes and its effect on overall thermal resistance. Application of the GMDH technique to predict HX fluid temperatures, and to compare with the calculated thermal resistance. √?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬∑ Development of a hybrid modeling technique for process diagnosis and its evaluation using laboratory heat exchanger test data. √?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬∑ Development and testing of a sensor suite using piezo-electric devices for monitoring structural integrity of both flat plates (beams) and tubing. Experiments were performed in air, and in water with and without bubbly flow. √?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬∑ Development of advanced signal processing methods using wavelet transforms and image processing techniques for isolating flaw types. √?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬?√?¬∑ Development and implementation of a new nonlinear and non-stationary signal processing method, called the Hilbert-Huang transform (HHT), for flaw detection and location. This is a more robust and adaptive approach compared to the wavelet transform

  13. A Zonotope-Based Method for Capturing the Effect of Variable Generation on the Power Flow

    E-Print Network [OSTI]

    Liberzon, Daniel

    of a power system; this uncertainty arises from the increasing penetration of renewable resources that the uncertain generation can take by a zonotope and propagate it through a linearized power flow model take values within a symmetric polytope. This uncertainty is propagated through the power system model

  14. A Set-Theoretic Framework to Assess the Impact of Variable Generation on the Power Flow

    E-Print Network [OSTI]

    Liberzon, Daniel

    penetration of renewable resources of electricity, such as wind and solar, into existing power systems. Since renewable resources vary in rated power output and point of grid interconnection, they affect power systems1 A Set-Theoretic Framework to Assess the Impact of Variable Generation on the Power Flow Xichen

  15. Co-flow anode/cathode supply heat exchanger for a solid-oxide fuel cell assembly

    DOE Patents [OSTI]

    Haltiner, Jr., Karl J.; Kelly, Sean M.

    2005-11-22T23:59:59.000Z

    In a solid-oxide fuel cell assembly, a co-flow heat exchanger is provided in the flow paths of the reformate gas and the cathode air ahead of the fuel cell stack, the reformate gas being on one side of the exchanger and the cathode air being on the other. The reformate gas is at a substantially higher temperature than is desired in the stack, and the cathode gas is substantially cooler than desired. In the co-flow heat exchanger, the temperatures of the reformate and cathode streams converge to nearly the same temperature at the outlet of the exchanger. Preferably, the heat exchanger is formed within an integrated component manifold (ICM) for a solid-oxide fuel cell assembly.

  16. Heat Transfer -2 A heat generating ( ) flat plate fuel element of thickness 2L is covered with flat plate steel cladding of

    E-Print Network [OSTI]

    Virginia Tech

    with flat plate steel cladding of thickness b. The heat generated is removed by a fluid at T, which adjoins on both sides On the sketch show regions where dT/dx is zero, constant and increasing. T , h x LL bb SteelSteel

  17. The effects of orientation angle, subcooling, heat flux, mass flux, and pressure on bubble growth and detachment in subcooled flow boiling

    E-Print Network [OSTI]

    Sugrue, Rosemary M

    2012-01-01T23:59:59.000Z

    The effects of orientation angle, subcooling, heat flux, mass flux, and pressure on bubble growth and detachment in subcooled flow boiling were studied using a high-speed video camera in conjunction with a two-phase flow ...

  18. Optimal homotopy perturbation method for nonlinear differential equations governing MHD Jeffery-Hamel flow with heat transfer problem

    E-Print Network [OSTI]

    Marinca, Vasile

    2015-01-01T23:59:59.000Z

    In this paper, Optimal Homotopy Perturbation Method (OHPM) is employed to determine an analytic approximate solutions for nonlinear MHD Jeffery-Hamel flow and heat transfer problem. The Navier-Stokes equations, taking into account Maxwell's electromagnetism and heat transfer lead to two nonlinear ordinary differential equations. The obtained results by means of OHPM show a very good agreement in comparison with the numerical results and with Homotopy Perturbation Method (HPM).

  19. CFD Simulations of a Flow Mixing and Heat Transfer Enhancement in an Advanced LWR Nuclear Fuel Assembly

    SciTech Connect (OSTI)

    In, Wang-Kee; Chun, Tae-Hyun; Shin, Chang-Hwan; Oh, Dong-Seok [Korea Atomic Energy Research Institute, 1045 Daedeokdaero, Yuseong-Gu, Daejeon, Korea 305-353 (Korea, Republic of)

    2007-07-01T23:59:59.000Z

    A computational fluid dynamics (CFD) analysis has been performed to investigate a flow-mixing and heat-transfer enhancement caused by a mixing-vane spacer in a LWR fuel assembly which is a rod bundle. This paper presents the CFD simulations of a flow mixing and heat transfer in a fully heated 5x5 array of a rod bundle with a split-vane and hybrid-vane spacer. The CFD prediction at a low Reynolds number of 42,000 showed a reasonably good agreement of the initial heat transfer enhancement with the measured one for a partially heated experiment using a similar spacer structure. The CFD simulation also predicted the decay rate of a normalized Nusselt number downstream of the split-vane spacer which agrees fairly well with those of the experiment and the correlation. The CFD calculations for the split vane and hybrid vane at the LWR operating conditions(Re = 500,000) predicted hot fuel spots in a streaky structure downstream of the spacer, which occurs due to the secondary flow occurring in an opposite direction near the fuel rod. However, the split-vane and hybrid-vane spacers are predicted to significantly enhance the overall heat transfer of a LWR nuclear fuel assembly. (authors)

  20. Heat flow of the Earth and resonant capture of solar 57-Fe axions

    E-Print Network [OSTI]

    F. A. Danevich; A. V. Ivanov; V. V. Kobychev; V. I. Tretyak

    2009-05-07T23:59:59.000Z

    In a very conservative approach, supposing that total heat flow of the Earth is exclusively due to resonant capture inside the Earth of axions, emitted by 57-Fe nuclei on Sun, we obtain limit on mass of hadronic axion: m_aEarth, this estimation could be improved to the value: m_a<1.6 keV. Both the values are less restrictive than limits set in devoted experiments to search for 57-Fe axions (m_a<216-745 eV), but are much better than limits obtained in experiments with 83-Kr (m_a<5.5 keV) and 7-Li (m_a<13.9-32 keV).

  1. Heat flow and subsurface temperature distributions in central and western New York. Final report

    SciTech Connect (OSTI)

    Hodge, D.S.; Fromm, K.

    1984-01-01T23:59:59.000Z

    Initiation of a geothermal energy program in western and central New York requires knowledge of subsurface temperatures for targeting areas of potential resources. The temperature distribution in possible geothermal reservoirs, calculated from heat flow measurements and modeling techniques, shows that a large area of New York can be considered for exploitation of geothermal resources. Though the temperatures at currently accessible depths show the availability of only a low-temperature (less than 100/sup 0/C), direct-use resource, this can be considered as an alternative for the future energy needs of New York State. From analysis of bottom-hole-temperature data and direct heat flow measurements, estimates of temperatures in the Cambrian Sandstones provide the basis of the economic evaluation of the reservoir. This reservoir contains the extractable fluids needed for targeting a potential geothermal well site in the low-temperature geothermal target zone. In the northern section of the Appalachian basin, reservoir temperatures in the Cambrian are below 50/sup 0/C but may be over 80/sup 0/C in the deeper parts of the basin in southern New York State. Using a minimum of 50/sup 0/C as a useful reservoir temperature, temperatures in excess of this value are encountered in the Theresa Formation at depths in excess of 1300 meters. Considering a maximum depth for economical drilling to be 2500 meters with present technology, the 2500 meters to the Theresa (sea level datum) forms the lower limit of the geothermal resource. Temperatures in the range of 70/sup 0/C to 80/sup 0/C are predicted for the southern portion of New York State.

  2. Proposal for the Award of a Contract for the Supply and Installation of a gas Turbine for Combined Generation of Electricity and Heat in the Heating Plant on the Meyrin Site

    E-Print Network [OSTI]

    1994-01-01T23:59:59.000Z

    Proposal for the Award of a Contract for the Supply and Installation of a gas Turbine for Combined Generation of Electricity and Heat in the Heating Plant on the Meyrin Site

  3. Waste Classification based on Waste Form Heat Generation in Advanced Nuclear Fuel Cycles Using the Fuel-Cycle Integration and Tradeoffs (FIT) Model

    SciTech Connect (OSTI)

    Denia Djokic; Steven J. Piet; Layne F. Pincock; Nick R. Soelberg

    2013-02-01T23:59:59.000Z

    This study explores the impact of wastes generated from potential future fuel cycles and the issues presented by classifying these under current classification criteria, and discusses the possibility of a comprehensive and consistent characteristics-based classification framework based on new waste streams created from advanced fuel cycles. A static mass flow model, Fuel-Cycle Integration and Tradeoffs (FIT), was used to calculate the composition of waste streams resulting from different nuclear fuel cycle choices. This analysis focuses on the impact of waste form heat load on waste classification practices, although classifying by metrics of radiotoxicity, mass, and volume is also possible. The value of separation of heat-generating fission products and actinides in different fuel cycles is discussed. It was shown that the benefits of reducing the short-term fission-product heat load of waste destined for geologic disposal are neglected under the current source-based radioactive waste classification system , and that it is useful to classify waste streams based on how favorable the impact of interim storage is in increasing repository capacity.

  4. Waste Classification based on Waste Form Heat Generation in Advanced Nuclear Fuel Cycles Using the Fuel-Cycle Integration and Tradeoffs (FIT) Model - 13413

    SciTech Connect (OSTI)

    Djokic, Denia [Department of Nuclear Engineering, University of California - Berkeley, 4149 Etcheverry Hall, Berkeley, CA 94720-1730 (United States)] [Department of Nuclear Engineering, University of California - Berkeley, 4149 Etcheverry Hall, Berkeley, CA 94720-1730 (United States); Piet, Steven J.; Pincock, Layne F.; Soelberg, Nick R. [Idaho National Laboratory - INL, 2525 North Fremont Avenue, Idaho Falls, ID 83415 (United States)] [Idaho National Laboratory - INL, 2525 North Fremont Avenue, Idaho Falls, ID 83415 (United States)

    2013-07-01T23:59:59.000Z

    This study explores the impact of wastes generated from potential future fuel cycles and the issues presented by classifying these under current classification criteria, and discusses the possibility of a comprehensive and consistent characteristics-based classification framework based on new waste streams created from advanced fuel cycles. A static mass flow model, Fuel-Cycle Integration and Tradeoffs (FIT), was used to calculate the composition of waste streams resulting from different nuclear fuel cycle choices. This analysis focuses on the impact of waste form heat load on waste classification practices, although classifying by metrics of radiotoxicity, mass, and volume is also possible. The value of separation of heat-generating fission products and actinides in different fuel cycles is discussed. It was shown that the benefits of reducing the short-term fission-product heat load of waste destined for geologic disposal are neglected under the current source-based radioactive waste classification system, and that it is useful to classify waste streams based on how favorable the impact of interim storage is in increasing repository capacity. (authors)

  5. A parametric study of shock jump chemistry, electron temperature, and radiative heat transfer models in hypersonic flows

    E-Print Network [OSTI]

    Greendyke, Robert Brian

    1988-01-01T23:59:59.000Z

    will examine the radiance model and various step models in order to determine their appropriateness to the flight regime of the AOTV. The final area to be investigated will be the effect of nonequilibrium corrections on the radiative heat transfer models... of T and e T will be valid as long as there is a reasonable amount vNs of nitrogen molecules in the flow. Radiative Heat Transfer Models For this study, four radiative heat transfer models were examined. One of these models is an optically thin radiance...

  6. Flow-induced tube vibration thresholds in heat exchangers from shellside water tests

    SciTech Connect (OSTI)

    Halle, H.; Chenoweth, J.M.; Wambsganss, M.W.

    1984-01-01T23:59:59.000Z

    Typical industrial shell-and-tube heat exchanger configurations are investigated experimentally for the occurrence of potentially damaging tube vibration as a function of flowrate. The effort is part of a program to develop vibration avoidance criteria to be integrated and optimized with the advanced thermal, hydraulic, and mechanical design methods now available. The tests use a 0.6-m (2-ft)-diameter, 3.7-m (12-ft)-long shell containing a removable tube bundle whose components are readily rearranged or replaced. The 15 different full tube bundle configurations tested represent various combinations of parameters: triangular or square tube layout patterns with different orientations to the flow, number of crosspasses, sizes of nozzles, plain or finned tubes. All bundles have 19-mm (0.75-in.)-diameter tubes spaced with a pitch-to-diameter ratio of 1.25. The heat exchanger is tested with waterflow on the shellside to determine a critical threshold, above which a small increase in the flowrate initiates a fluidelastic instability resulting in large amplitude vibration. The test conditions, the critical flowrates, the vibration frequencies, and the locations of the tubes most susceptible to vibration are presented. The given data are used for a comparison with a presently recognized method of vibration prediction and will permit updated evaluations as more advanced methods become available in the future.

  7. Quality Assurance Plan for Heat Source/Radioisotope Thermoelectric Generator Programs

    SciTech Connect (OSTI)

    Gabriel, D. M.; Miller, G. D.; Bohne, W. A.

    1995-03-16T23:59:59.000Z

    The purpose of this document is to serve as the Quality Assurance Plan for Heat Source/Radioisotope Thermoelectric Generator (HS/RTG) programs performed at EG&G Mound Applied Technologies. As such, it identifies and describes the systems and activities in place to support the requirements contained in DOE Order 5700.6C as reflected in MD-10334, Mound Quality Policy and Responsibilities and the DOE/RPSD supplement, OSA/PQAR-1, Programmatic Quality Assurance Requirements for Space and Terrestrial Nuclear Power Systems. Unique program requirements, including additions, modifications, and exceptions to these quality requirements, are contained in the appendices of this plan. Additional appendices will be added as new programs and activities are added to Mound's HS/RTG mission assignment.

  8. Modeling of reciprocating internal combustion engines for power generation and heat recovery

    SciTech Connect (OSTI)

    Yun, Kyung Tae; Cho, Heejin; Luck, Rogelio; Mago, Pedro J.

    2013-02-01T23:59:59.000Z

    This paper presents a power generation and heat recovery model for reciprocating internal combustion engines (ICEs). The purpose of the proposed model is to provide realistic estimates of performance/efficiency maps for both electrical power output and useful thermal output for various capacities of engines for use in a preliminary CHP design/simulation process. The proposed model will serve as an alternative to constant engine efficiencies or empirical efficiency curves commonly used in the current literature for simulations of CHP systems. The engine performance/efficiency calculation algorithm has been coded to a publicly distributed FORTRAN Dynamic Link Library (DLL), and a user friendly tool has been developed using Visual Basic programming. Simulation results using the proposed model are validated against manufacturerís technical data.

  9. Evaluation of a once-through heat recovery steam generator concept: Final report

    SciTech Connect (OSTI)

    Babione, R.A.

    1988-04-01T23:59:59.000Z

    This report presents the results of a reliability, availability, and maintainability (RAM) evaluation of a once-through concept for a combined-cycle heat recovery steam generator (HRSG). The project included a review of differences in reliability and maintainability characteristics of the once-through concept and a typical drum-type HRSG design. A special effort was placed on an investigation of the expected performance of the thin-wall alloy 800 boiler tubing used in the once-through HRSG. An analysis was performed by using the UNIRAM computer modeling methodology to compare the predicted availability of the once-through HRSG design with that of a drum-type system. The results of this project provide a basis for understanding the RAM characteristics of the once-through HRSG concept and identify areas where additional research may be beneficial in evaluating this new design for application within the utility industry. 28 refs., 5 figs., 7 tabs.

  10. Structural testing of the Los Alamos National Laboratory Heat Source/Radioisotopic Thermoelectric Generator shipping container

    SciTech Connect (OSTI)

    Bronowski, D.R.; Madsen, M.M.

    1991-06-01T23:59:59.000Z

    The Heat Source/Radioisotopic Thermoelectric Generator shipping container is a Type B packaging design currently under development by Los Alamos National Laboratory. Type B packaging for transporting radioactive material is required to maintain containment and shielding after being exposed to the normal and hypothetical accident environments defined in Title 10 Code of Federal Regulations Part 71. A combination of testing and analysis is used to verify the adequacy of this package design. This report documents the test program portion of the design verification, using several prototype packages. Four types of testing were performed: 30-foot hypothetical accident condition drop tests in three orientations, 40-inch hypothetical accident condition puncture tests in five orientations, a 21 psi external overpressure test, and a normal conditions of transport test consisting of a water spray and a 4 foot drop test. 18 refs., 104 figs., 13 tabs.

  11. Certification testing of the Los Alamos National Laboratory Heat Source/Radioisotopic Thermoelectric Generator shipping container

    SciTech Connect (OSTI)

    Bronowski, D.R.; Madsen, M.M.

    1991-09-01T23:59:59.000Z

    The Heat Source/Radioisotopic Thermoelectric Generator shipping counter is a Type B packaging currently under development by Los Alamos National Laboratory. Type B packaging for transporting radioactive material is required to maintain containment and shielding after being exposed to normal and hypothetical accident environments defined in Title 10 of the Code of Federal Regulations Part 71. A combination of testing and analysis is used to verify the adequacy of this packaging design. This report documents the testing portion of the design verification. Six tests were conducted on a prototype package: a water spray test, a 4-foot normal conditions drop test, a 30-foot drop test, a 40-inch puncture test, a 30-minute thermal test, and an 8-hour immersion test.

  12. UNSAT-H Version 2. 0: Unsaturated soil water and heat flow model

    SciTech Connect (OSTI)

    Fayer, M.J.; Jones, T.L.

    1990-04-01T23:59:59.000Z

    This report documents UNSAT-H Version 2.0, a model for calculating water and heat flow in unsaturated media. The documentation includes the bases for the conceptual model and its numerical implementation, benchmark test cases, example simulations involving layered soils and plant transpiration, and the code listing. Waste management practices at the Hanford Site have included disposal of low-level wastes by near-surface burial. Predicting the future long-term performance of any such burial site in terms of migration of contaminants requires a model capable of simulating water flow in the unsaturated soils above the buried waste. The model currently used to meet this need is UNSAT-H. This model was developed at Pacific Northwest Laboratory to assess water dynamics of near-surface, waste-disposal sites at the Hanford Site. The code is primarily used to predict deep drainage as a function of such environmental conditions as climate, soil type, and vegetation. UNSAT-H is also used to simulate the effects of various practices to enhance isolation of wastes. 66 refs., 29 figs., 7 tabs.

  13. Finite element analysis of conjugate heat transfer in axisymmetric pipe flows

    E-Print Network [OSTI]

    Fithen, Robert Miller

    1987-01-01T23:59:59.000Z

    with no axial fluid conduction, such as liquid water at a moderate to high Reynolds number. Detailed fluid ? solid interface heat flux, Nusselt number, wall, and bulk temperatures for each case are presented. The results indicate axial wall conduction is very... model for a circular tube Comparison for constant heat flux case Comparison for constant temperature case Heat flux for Pe=5, constant heat flux case Heat flux for Pe=50, constant heat flux case Heat flux for Pe=200, constant heat flux case Heat...

  14. Corrosion-induced gas generation in a nuclear waste repository: Reactive geochemistry and multiphase flow effect

    SciTech Connect (OSTI)

    Xu, T.; Senger, R.; Finsterle, S.

    2008-10-15T23:59:59.000Z

    Corrosion of steel canisters, stored in a repository for spent fuel and high-level nuclear wastes, leads to the generation and accumulation of hydrogen gas in the backfilled emplacement tunnels, which may significantly affect long-term repository safety. Previous studies used H{sub 2} generation rates based on the volume of the waste or canister material and the stoichiometry of the corrosion reaction. However, iron corrosion and H{sub 2} generation rates vary with time, depending on factors such as amount of iron, water availability, water contact area, and aqueous and solid chemistry. To account for these factors and feedback mechanisms, we developed a chemistry model related to iron corrosion, coupled with two-phase (liquid and gas) flow phenomena that are driven by gas-pressure buildup associated with H{sub 2} generation and water consumption. Results indicate that by dynamically calculating H{sub 2} generation rates based on a simple model of corrosion chemistry, and by coupling this corrosion reaction with two-phase flow processes, the degree and extent of gas pressure buildup could be much smaller compared to a model that neglects the coupling between flow and reactive transport mechanisms. By considering the feedback of corrosion chemistry, the gas pressure increases initially at the canister, but later decreases and eventually returns to a stabilized pressure that is slightly higher than the background pressure. The current study focuses on corrosion under anaerobic conditions for which the coupled hydrogeochemical model was used to examine the role of selected physical parameters on the H{sub 2} gas generation and corresponding pressure buildup in a nuclear waste repository. The developed model can be applied to evaluate the effect of water and mineral chemistry of the buffer and host rock on the corrosion reaction for future site-specific studies.

  15. Rapid embedded wire heating via resistive guiding of laser-generated fast electrons as a hydrodynamic driver

    SciTech Connect (OSTI)

    Robinson, A. P. L.; Schmitz, H. [Central Laser Facility, STFC Rutherford-Appleton Laboratory, Didcot OX11 0QX (United Kingdom)] [Central Laser Facility, STFC Rutherford-Appleton Laboratory, Didcot OX11 0QX (United Kingdom); Pasley, J. [Central Laser Facility, STFC Rutherford-Appleton Laboratory, Didcot OX11 0QX (United Kingdom) [Central Laser Facility, STFC Rutherford-Appleton Laboratory, Didcot OX11 0QX (United Kingdom); York Plasma Institute, University of York, York YO10 5DD (United Kingdom)

    2013-12-15T23:59:59.000Z

    Resistively guiding laser-generated fast electron beams in targets consisting of a resistive wire embedded in lower Z material should allow one to rapidly heat the wire to over 100 eV over a substantial distance without strongly heating the surrounding material. On the multi-ps timescale, this can drive hydrodynamic motion in the surrounding material. Thus, ultra-intense laser solid interactions have the potential as a controlled driver of radiation hydrodynamics in solid density material. In this paper, we assess the laser and target parameters needed to achieve such rapid and controlled heating of the embedded wire.

  16. P~!ETRIC STUDY OF HEAT FLOW DURING RESISTANCE SPOT WELDING Euiwhan Kim and Thomas W. Eagar

    E-Print Network [OSTI]

    Eagar, Thomas W.

    i ...) P~!ETRIC STUDY OF HEAT FLOW DURING RESISTANCE SPOT WELDING Euiwhan Kim and Thomas W. Eagar case of resistance welding to see the effects of each parameter on the lobe shape. The parameters include material proper- ties, geometry of electrodes and work piece, weld time and current

  17. 5th International Symposium on Multiphase Flow, Heat Mass Transfer and Energy Conversion Xian, China, 36 July 2005

    E-Print Network [OSTI]

    Aguilar, Guillermo

    5th International Symposium on Multiphase Flow, Heat Mass Transfer and Energy Conversion Xian, such as hemangiomas and port wine stain (PWS) birthmarks, are congenital and pro- gressive vascular malformations of the dermis. To remove them, laser energy is irradiated at appropriate wavelengths inducing permanent thermal

  18. Pressure drop, heat transfer, critical heat flux, and flow stability of two-phase flow boiling of water and ethylene glycol/water mixtures - final report for project "Efficent cooling in engines with nucleate boiling."

    SciTech Connect (OSTI)

    Yu, W.; France, D. M.; Routbort, J. L. (Energy Systems)

    2011-01-19T23:59:59.000Z

    Because of its order-of-magnitude higher heat transfer rates, there is interest in using controllable two-phase nucleate boiling instead of conventional single-phase forced convection in vehicular cooling systems to remove ever increasing heat loads and to eliminate potential hot spots in engines. However, the fundamental understanding of flow boiling mechanisms of a 50/50 ethylene glycol/water mixture under engineering application conditions is still limited. In addition, it is impractical to precisely maintain the volume concentration ratio of the ethylene glycol/water mixture coolant at 50/50. Therefore, any investigation into engine coolant characteristics should include a range of volume concentration ratios around the nominal 50/50 mark. In this study, the forced convective boiling heat transfer of distilled water and ethylene glycol/water mixtures with volume concentration ratios of 40/60, 50/50, and 60/40 in a 2.98-mm-inner-diameter circular tube has been investigated in both the horizontal flow and the vertical flow. The two-phase pressure drop, the forced convective boiling heat transfer coefficient, and the critical heat flux of the test fluids were determined experimentally over a range of the mass flux, the vapor mass quality, and the inlet subcooling through a new boiling data reduction procedure that allowed the analytical calculation of the fluid boiling temperatures along the experimental test section by applying the ideal mixture assumption and the equilibrium assumption along with Raoult's law. Based on the experimental data, predictive methods for the two-phase pressure drop, the forced convective boiling heat transfer coefficient, and the critical heat flux under engine application conditions were developed. The results summarized in this final project report provide the necessary information for designing and implementing nucleate-boiling vehicular cooling systems.

  19. Apparatus and method for characterizing thin film and interfaces using an optical heat generator and detector

    DOE Patents [OSTI]

    Maris, H.J.; Stoner, R.J.

    1998-05-05T23:59:59.000Z

    An optical heat generation and detection system generates a first non-destructive pulsed beam of electromagnetic radiation that is directed upon a sample containing at least one interface between similar or dissimilar materials. The first pulsed beam of electromagnetic radiation, a pump beam, produces a non-uniform temperature change within the sample. A second non-destructive pulsed beam of electromagnetic radiation, a probe beam, is also directed upon the sample. Physical and chemical properties of the materials, and of the interface, are measured by observing changes in a transient optical response of the sample to the probe beam, as revealed by a time dependence of changes in, by example, beam intensity, direction, or state of polarization. The system has increased sensitivity to interfacial properties including defects, contaminants, chemical reactions and delaminations, as compared to conventional non-destructive, non-contact techniques. One feature of this invention is a determination of a Kapitza resistance at the interface, and the correlation of the determined Kapitza resistance with a characteristic of the interface, such as roughness, delamination, the presence of contaminants, etc. 31 figs.

  20. Apparatus and method for characterizing thin film and interfaces using an optical heat generator and detector

    DOE Patents [OSTI]

    Maris, Humphrey J (Barrington, RI); Stoner, Robert J (Duxbury, MA)

    1998-01-01T23:59:59.000Z

    An optical heat generation and detection system generates a first non-destructive pulsed beam of electromagnetic radiation that is directed upon a sample containing at least one interface between similar or dissimilar materials. The first pulsed beam of electromagnetic radiation, a pump beam (21a), produces a non-uniform temperature change within the sample. A second non-destructive pulsed beam of electromagnetic radiation, a probe beam (21b), is also directed upon the sample. Physical and chemical properties of the materials, and of the interface, are measured by observing changes in a transient optical response of the sample to the probe beam, as revealed by a time dependence of changes in, by example, beam intensity, direction, or state of polarization. The system has increased sensitivity to interfacial properties including defects, contaminants, chemical reactions and delaminations, as compared to conventional non-destructive, non-contact techniques. One feature of this invention is a determination of a Kapitza resistance at the interface, and the correlation of the determined Kapitza resistance with a characteristic of the interface, such as roughness, delamination, the presence of contaminants, etc.

  1. Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01T23:59:59.000Z

    tool for geothermal water loop heat pump systems, 9thInternational IEA Heat Pump Conference, ZŁrich, Switzerland,Performance of ground source heat pump system in a near-zero

  2. Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01T23:59:59.000Z

    multiple water-to-air heat pump units, which are connectedeach of the water-to-air heat pump units can run in eitheras other types of air source heat pumps, VRF systems need

  3. Closed cycle MHD generator with nonuniform gas-plasma flow driving recombinated plasma clots

    SciTech Connect (OSTI)

    Slavin, V.S. [Krasnoyarsk State Technical Univ. (Russian Federation); Danilov, V.V.; Sokolov, V.S. [Krasnoyarsk State Univ. (Russian Federation)

    1996-12-31T23:59:59.000Z

    A new concept of a closed cycle MHD generator without alkali seed has been suggested. The essence of it is the phenomenon of frozen conductivity for recombined plasma which appears for noble gas at T{sub e} > 4,000 K. At the inlet of the MHD channel in supersonic flow of noble gas (He or Ar) the plasma clots with electron density about 10{sup 15} cm{sup {minus}3} are formed by pulsed intense electron beam with energy about 300 keV. Gas flow drives these clots in a cross magnetic field along the MHD channel which has electrodes connected with the load by Faraday scheme. The gas flow pushes plasma layers and produces electric power at the expense of enthalpy extraction. The numerical simulation has shown that a supersonic gas flow, containing about 4 plasma layers in the MHD channel simultaneously, is braked without shock waves creation. This type of the MHD generator can provide more than 30% enthalpy extraction ratio and about 80% isentropic efficiency. The advantages of the new concept are the following: (a) possibility of working at higher pressure and lower temperature, (b) operation with alkali seed.

  4. Triple loop heat exchanger for an absorption refrigeration system

    DOE Patents [OSTI]

    Reimann, Robert C. (Lafayette, NY)

    1984-01-01T23:59:59.000Z

    A triple loop heat exchanger for an absorption refrigeration system is disclosed. The triple loop heat exchanger comprises portions of a strong solution line for conducting relatively hot, strong solution from a generator to a solution heat exchanger of the absorption refrigeration system, conduit means for conducting relatively cool, weak solution from the solution heat exchanger to the generator, and a bypass system for conducting strong solution from the generator around the strong solution line and around the solution heat exchanger to an absorber of the refrigeration system when strong solution builds up in the generator to an undesirable level. The strong solution line and the conduit means are in heat exchange relationship with each other in the triple loop heat exchanger so that, during normal operation of the refrigeration system, heat is exchanged between the relatively hot, strong solution flowing through the strong solution line and the relatively cool, weak solution flowing through the conduit means. Also, the strong solution line and the bypass system are in heat exchange relationship in the triple loop heat exchanger so that if the normal flow path of relatively hot, strong solution flowing from the generator to an absorber is blocked, then this relatively, hot strong solution which will then be flowing through the bypass system in the triple loop heat exchanger, is brought into heat exchange relationship with any strong solution which may have solidified in the strong solution line in the triple loop heat exchanger to thereby aid in desolidifying any such solidified strong solution.

  5. Subcooled flow boiling heat transfer and critical heat flux in water-based nanofluids at low pressure

    E-Print Network [OSTI]

    Kim, Sung Joong, Ph. D. Massachusetts Institute of Technology

    2009-01-01T23:59:59.000Z

    A nanofluid is a colloidal suspension of nano-scale particles in water, or other base fluids. Previous pool boiling studies have shown that nanofluids can improve the critical heat flux (CHF) by as much as 200%. In this ...

  6. Temporal Entropy Generation in the Viscous Layers of Laterally-converging Duct Flows

    SciTech Connect (OSTI)

    Donald M. McEligot; Robert S. Brodkey; Helmut Eckelmann

    2008-12-01T23:59:59.000Z

    Since insight into entropy generation is a key to increasing efficiency and thereby reducing fuel consumption and/or waste and -- for wall-bounded flows -- most entropy is generated in the viscous layer, we examine the transient behavior of its dominant contributor there for a non-canonical flow. New measurements in oil flow are presented for the effects of favorable streamwise mean pressure gradients on temporal entropy generation rates and, in the process, on key Reynolds-stress-producing events such as sweep front passage and on the deceleration/outflow phase of the overall bursting process. Two extremes have been considered: (1) a high pressure gradient, nearing "laminarization," and (2), for comparison, a low pressure gradient corresponding to many earlier experiments. In both cases, the peak temporal entropy generation rate occurs shortly after passage of the ejection/sweep interface. Whether sweep and ejection rates appear to decrease or increase with the pressure gradient depends on the feature examined and the manner of sampling. When compared using wall coordinates for velocities, distances and time, the trends and magnitudes of the transient behaviors are mostly the same. The main effects of the higher pressure gradient are (1) changes in the time lag between detections -- representing modification of the shape of the sweep front and the sweep angle with the wall, (2) modification of the magnitude of an instantaneous Reynolds shear stress with wall distance and (3) enlarging the sweeps and ejections. Results new for both low and high pressure gradients are the temporal behaviors of the dominant contribution to entropy generation; it is found to be much more sensitive to distance from the wall than to streamwise pressure gradient.

  7. Heat pump system

    DOE Patents [OSTI]

    Swenson, Paul F.; Moore, Paul B.

    1983-06-21T23:59:59.000Z

    An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

  8. Heat pump system

    DOE Patents [OSTI]

    Swenson, Paul F. (Shaker Heights, OH); Moore, Paul B. (Fedhaven, FL)

    1983-01-01T23:59:59.000Z

    An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

  9. Development of Technologies on Innovative-Simplified Nuclear Power Plant Using High-Efficiency Steam Injectors (12) Evaluations of Spatial Distributions of Flow and Heat Transfer in Steam Injector

    SciTech Connect (OSTI)

    Yutaka Abe; Yujiro Kawamoto [University of Tsukuba, Tsukuba, Ibaraki (Japan); Chikako Iwaki [Toshiba Corporation (Japan); Tadashi Narabayashi [Hokkaido University, Kita-ku, Sapporo (Japan); Michitsugu Mori; Shuichi Ohmori [Tokyo Electric Power Company (Japan)

    2006-07-01T23:59:59.000Z

    Next-generation nuclear reactor systems have been under development aiming at simplified system and improvement of safety and credibility. One of the innovative technologies is the supersonic steam injector, which has been investigated as one of the most important component of the next-generation nuclear reactor. The steam injector has functions of a passive pump without large motor or turbo-machinery and a high efficiency heat exchanger. The performances of the supersonic steam injector as a pump and a heat exchanger are dependent on direct contact condensation phenomena between a supersonic steam and a sub-cooled water jet. In previous studies of the steam injector, there are studies about the operating characteristics of steam injector and about the direct contact condensation between static water pool and steam in atmosphere. However, there is a little study about the turbulent heat transfer and flow behavior under the great shear stress. In order to examine the heat transfer and flow behavior in supersonic steam injector, it is necessary to measure the spatial temperature distribution and velocity in detail. The present study, visible transparent supersonic steam injector is used to obtain the axial pressure distributions in the supersonic steam injector, as well as high speed visual observation of water jet and steam interface. The experiments are conducted with and without non-condensable gas. The experimental results of the interfacial flow behavior between steam and water jet are obtained. It is experimentally clarified that an entrainment exists on the water jet surface. It is also clarified that discharge pressure is depended on the steam supply pressure, the inlet water flow rate, the throat diameter and non-condensable flow rate. Finally a heat flux is estimated about 19 MW/m{sup 2} without non-condensable gas condition in steam. (authors)

  10. Numerical Study of Convective Heat Transfer in Flat Tube Heat Exchangers Operating in Self-Sustained Oscillatory Flow Regimes

    E-Print Network [OSTI]

    Fullerton, Tracy

    2012-02-14T23:59:59.000Z

    characterized by cyclic variations of flow parameters such as stream-wise or cross-stream velocity. A computer code was developed to perform the numerical simulations. Spatial discretization was based upon a Control Volume Finite Element Method (CVFEM...

  11. Proceedings: International Conference on Boiler Tube Failures and Heat Recovery Steam Generator (HRSG) Tube Failures and Inspections

    SciTech Connect (OSTI)

    None

    2002-10-01T23:59:59.000Z

    Tube failures remain the leading cause of availability loss in conventional fossil plants and combined cycle/heat recovery steam generator (HRSG) plants. These conference proceedings address state-of-the-art practices and techniques worldwide for understanding and reducing tube failures.

  12. The lower hybrid (LH) heating and current drive system can generate 10-12 MW of microwave power

    E-Print Network [OSTI]

    Background The lower hybrid (LH) heating and current drive system can generate 10-12 MW reflecting optics · Remote vacuum window manufactured by CCFE · Industrial contract for periscope manufacture with Zemax model · Remote, IR compatible, double vacuum window with pumped interspace · 4, two colour

  13. Testing the improved method for calculating the radiation heat generation at the periphery of the BOR-60 reactor core

    SciTech Connect (OSTI)

    Varivtsev, A. V., E-mail: vav3@niiar.ru; Zhemkov, I. Yu. [JSC ďSSC RIAR,Ē Dimitrovgrad-10 (Russian Federation)

    2014-12-15T23:59:59.000Z

    The application of the improved method for calculating the radiation heat generation in the elements of an experimental device located at the periphery of the BOR-60 reactor core results in a significant reduction in the discrepancies between the calculated and the experimental data. This allows us to conclude that the improved method has an advantage over the one used earlier.

  14. Municipal District Heating and Cooling Co-generation System Feasibility Research†

    E-Print Network [OSTI]

    Zhang, W.; Guan, W.; Pan, Y.; Ding, G.; Song, X.; Zhang, Y.; Li, Y.; Wei, H.; He, Y.

    2006-01-01T23:59:59.000Z

    In summer absorption refrigerating machines provide cold water using excess heat from municipal thermoelectric power plant through district heating pipelines, which reduces peak electric load from electricity networks in summer. The paper simulates...

  15. Municipal District Heating and Cooling Co-generation System Feasibility Research

    E-Print Network [OSTI]

    Zhang, W.; Guan, W.; Pan, Y.; Ding, G.; Song, X.; Zhang, Y.; Li, Y.; Wei, H.; He, Y.

    2006-01-01T23:59:59.000Z

    In summer absorption refrigerating machines provide cold water using excess heat from municipal thermoelectric power plant through district heating pipelines, which reduces peak electric load from electricity networks in summer. The paper simulates...

  16. Hydrogen Generation in Microbial Reverse-Electrodialysis Electrolysis Cells Using a Heat-Regenerated Salt Solution

    E-Print Network [OSTI]

    , which can be regenerated using low-temperature waste heat, can also produce sufficient voltage technologies and waste heat making the MREC a useful method for hydrogen gas production from wastes

  17. Rotary magnetic heat pump

    DOE Patents [OSTI]

    Kirol, Lance D. (Shelly, ID)

    1988-01-01T23:59:59.000Z

    A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation.

  18. Rotary magnetic heat pump

    DOE Patents [OSTI]

    Kirol, L.D.

    1987-02-11T23:59:59.000Z

    A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation. 5 figs.

  19. Interlaboratory comparison of four heat flow meter apparatuses on planed polyisocyanurate boards foamed with CFC-11

    SciTech Connect (OSTI)

    Graves, R.S.; McElroy, D.L. (Oak Ridge National Lab., TN (USA)); Miller, R.G. (Walter (Jim) Research Corp., St. Petersburg, FL (USA)); Yarbrough, D.W. (Tennessee Technological Univ., Cookeville, TN (USA)); Zarr, R.R. (National Inst. of Standards and Technology, Gaithersburg, MD (USA))

    1991-06-01T23:59:59.000Z

    This report describes an interlaboratory comparison of apparent thermal conductivity (k) results on planed polyisocyanurate (PIR) boards foamed with chlorofluorocarbon-11 (CFC-11). Sequential tests were conducted at 75{degrees}F (24{degrees}C) at four facilities on two rigid (PIR) boards, individually and as a pair, using four comparative heat flow meter apparatuses. The specimens were shipped from lab to lab, and testing yielded 15 k-values that have two standard deviation (2 {alpha}) value of 2.2% when described by: k(Btu{center dot}in./h{center dot}ft{sup 2}{center dot}F) = 0/1365 + 1.15 {times} 10{sup {minus}4} t k(W/m{center dot}K) = 0.0197 + 1.66 {times} 10{sup {minus}5} t, where t is the elapsed time in days after planing of the boards. An increased 2 {sigma} value for board 2 may be associated with a larger variation in thickness. The 15 thermal conductance (C) values have a 2 {sigma} value of 3.2% when described by: C(Btu/H{center dot}h{center dot}{sup 2}{center dot}{degrees}F) = 0.1069 + 1.20 {times} 10{sup {minus}4} t. Thus, the 2 {sigma} (k-values) of the interlaboratory comparison is not reduced by comparing C values. 5 refs., 1 fig., 8 tabs.

  20. The 1983 Temperature Gradient and Heat Flow Drilling Project for the State of Washington

    SciTech Connect (OSTI)

    Korosec, Michael A.

    1983-11-01T23:59:59.000Z

    During the Summer of 1983, the Washington Division of Geology and Earth Resources carried out a three-hole drilling program to collect temperature gradient and heat flow information near potential geothermal resource target areas. The project was part of the state-coupled US Department of Energy Geothermal Program. Richardson Well Drilling of Tacoma, Washington was subcontracted through the State to perform the work. The general locations of the project areas are shown in figure 1. The first hole, DNR 83-1, was located within the Green River valley northwest of Mount St. Helens. This site is near the Green River Soda Springs and along the projection of the Mount St. Helens--Elk Lake seismic zone. The other two holes were drilled near Mount Baker. Hole DNR 83-3 was sited about 1/4 km west of the Baker Hot Springs, 10.5 km east of Mount Baker, while hole DNR 83-5 was located along Rocky Creek in the Sulphur Creek Valley. The Rocky Creek hole is about 10 km south-southwest of the peak. Two other holes, DNR 83-2 and DNR 83-4, were located on the north side of the Sulphur Creek Valley. Both holes were abandoned at early stages of drilling because of deep overburden and severe caving problems. The sites were apparently located atop old landslide deposits.

  1. Modeling a Printed Circuit Heat Exchanger with RELAP5-3D for the Next Generation Nuclear Plant

    SciTech Connect (OSTI)

    Not Available

    2010-12-01T23:59:59.000Z

    The main purpose of this report is to design a printed circuit heat exchanger (PCHE) for the Next Generation Nuclear Plant and carry out Loss of Coolant Accident (LOCA) simulation using RELAP5-3D. Helium was chosen as the coolant in the primary and secondary sides of the heat exchanger. The design of PCHE is critical for the LOCA simulations. For purposes of simplicity, a straight channel configuration was assumed. A parallel intermediate heat exchanger configuration was assumed for the RELAP5 model design. The RELAP5 modeling also required the semicircular channels in the heat exchanger to be mapped to rectangular channels. The initial RELAP5 run outputs steady state conditions which were then compared to the heat exchanger performance theory to ensure accurate design is being simulated. An exponential loss of pressure transient was simulated. This LOCA describes a loss of coolant pressure in the primary side over a 20 second time period. The results for the simulation indicate that heat is initially transferred from the primary loop to the secondary loop, but after the loss of pressure occurs, heat transfers from the secondary loop to the primary loop.

  2. A shielded storage and processing facility for radioisotope thermoelectric generator heat source production

    SciTech Connect (OSTI)

    Sherrell, D.L.

    1992-06-01T23:59:59.000Z

    This report discusses a shielded storage rack which has been installed as part of the Radioisotope Power Systems Facility (RPSF) at the US Department of Energy's (DOE) Hanford Site in Washington State. The RPSF is designed to replace an existing facility at DOE's Mound Site near Dayton, Ohio, where General Purpose Heat Source (GPHS) modules are currently assembled and installed into Radioisotope Thermoelectric Generators (RTG). The overall design goal of the RPSF is to increase annual production throughput, while at the same time reducing annual radiation exposure to personnel. The shield rack design successfully achieved this goal for the Module Reduction and Monitoring Facility (MRMF), which process and stores assembled GPHS modules, prior to their installation into RTGS. The shield rack design is simple and effective, with the result that background radiation levels within Hanford's MRMF room are calculated at just over three percent of those typically experienced during operation of the existing MRMF at Mound, despite the fact that Hanford's calculations assume five times the GPHS inventory of that assumed for Mound.

  3. A shielded storage and processing facility for radioisotope thermoelectric generator heat source production

    SciTech Connect (OSTI)

    Sherrell, D.L.

    1992-06-01T23:59:59.000Z

    This report discusses a shielded storage rack which has been installed as part of the Radioisotope Power Systems Facility (RPSF) at the US Department of Energy`s (DOE) Hanford Site in Washington State. The RPSF is designed to replace an existing facility at DOE`s Mound Site near Dayton, Ohio, where General Purpose Heat Source (GPHS) modules are currently assembled and installed into Radioisotope Thermoelectric Generators (RTG). The overall design goal of the RPSF is to increase annual production throughput, while at the same time reducing annual radiation exposure to personnel. The shield rack design successfully achieved this goal for the Module Reduction and Monitoring Facility (MRMF), which process and stores assembled GPHS modules, prior to their installation into RTGS. The shield rack design is simple and effective, with the result that background radiation levels within Hanford`s MRMF room are calculated at just over three percent of those typically experienced during operation of the existing MRMF at Mound, despite the fact that Hanford`s calculations assume five times the GPHS inventory of that assumed for Mound.

  4. A shielded storage and processing facility for radioisotope thermoelectric generator heat source production

    SciTech Connect (OSTI)

    Sherrell, D.L. (Westinghouse Hanford Company, P.O. Box 1970, Mail Stop N1-42, Richland, Washington 99352 (United States))

    1993-01-15T23:59:59.000Z

    A shielded storage rack has been installed as part of the Radioisotope Power Systems Facility (RPSF) at the U.S. Department of Energy's (DOE) Hanford Site in Washington State. The RPSF is designed to replace an existing facility at DOE's Mound Site near Dayton, Ohio, where General Purpose Heat Source (GPHS) modules are currently assembled and installed into Radioisotope Thermoelectric Generators (RTG). The overall design goal of the RPSF is to increase annual production throughput, while at the same time reducing annual radiation exposure to personnel. The shield rack design successfully achieved this goal for the Module Reduction and Monitoring Facility (MRMF), which processes and stores assembled GPHS modules, prior to their installation into RTGs. The shield rack design is simple and effective, with the result that background radiation levels within Hanford's MRMF room are calculated at just over three percent of those typically experienced during operation of the existing MRMF at Mound, despite the fact that Hanford's calculations assume five times the GPHS inventory of that assumed for Mound.

  5. Thermoelectric generators incorporating phase-change materials for waste heat recovery from engine exhaust

    DOE Patents [OSTI]

    Meisner, Gregory P; Yang, Jihui

    2014-02-11T23:59:59.000Z

    Thermoelectric devices, intended for placement in the exhaust of a hydrocarbon fuelled combustion device and particularly suited for use in the exhaust gas stream of an internal combustion engine propelling a vehicle, are described. Exhaust gas passing through the device is in thermal communication with one side of a thermoelectric module while the other side of the thermoelectric module is in thermal communication with a lower temperature environment. The heat extracted from the exhaust gasses is converted to electrical energy by the thermoelectric module. The performance of the generator is enhanced by thermally coupling the hot and cold junctions of the thermoelectric modules to phase-change materials which transform at a temperature compatible with the preferred operating temperatures of the thermoelectric modules. In a second embodiment, a plurality of thermoelectric modules, each with a preferred operating temperature and each with a uniquely-matched phase-change material may be used to compensate for the progressive lowering of the exhaust gas temperature as it traverses the length of the exhaust pipe.

  6. The Long-Life Core Encapsulated Nuclear Heat Source (ENHS) Generation IV Reactor

    SciTech Connect (OSTI)

    Greenspan, E.; Barak, A.; Saphier, D. [Department of Nuclear Engineering, University of California, Berkeley, CA 94720 (United States); Buongiorno, J. [Idaho National Engineering and Environmental Laboratory, P.O. Box 1625, Idaho Falls, ID 83415 (United States); Brown, N.W.; Hossain, Q. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Carelli, M.D.; Conway, L.; Dzodzo, M. [Westinghouse Electric Co., Sci. and Tech., 1344 Beulah Rd., Pittsburgh, PA 15235 (United States); Feldman, E.; Sienicki, J.J.; Sofu, T.; Wade, D.C. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Hong, S.G.; Kim, Y.I. [Korea Atomic Energy Research Institute, Yusong, Taejon 305-600, Rep. of Korea (Korea, Republic of)

    2002-07-01T23:59:59.000Z

    The long-life core for the Encapsulated Nuclear Heat Source (ENHS) reactor has been redesigned so as to provide for fuel rod clad integrity up to the discharge burnup design goal. It was found feasible to design a nearly zero burnup reactivity swing long-life core that will maintain the fuel rod integrity up to the peak discharge burnup while enabling to handle the rated power using natural circulation. The core life is limited by radiation damage to its structural material. The core power shape is exceptionally constant throughout the core life. The new reference core design can deliver 125 MW{sub th} while having very generous margins for maximum acceptable temperatures or temperature differences. Using a cover-gas lift-pump it may be possible to design an ENHS module to deliver {approx}50% more power than the set goal. Briefly reviewed are unique features of the ENHS reactor along with the potential of this reactor to meet the goals set for Generation IV reactors. (authors)

  7. Continuous-wave radar to detect defects within heat exchangers and steam generator tubes.

    SciTech Connect (OSTI)

    Nassersharif, Bahram (New Mexico State University, Las Cruces, NM); Caffey, Thurlow Washburn Howell; Jedlicka, Russell P. (New Mexico State University, Las Cruces, NM); Garcia, Gabe V. (New Mexico State University, Las Cruces, NM); Rochau, Gary Eugene

    2003-01-01T23:59:59.000Z

    A major cause of failures in heat exchangers and steam generators in nuclear power plants is degradation of the tubes within them. The tube failure is often caused by the development of cracks that begin on the outer surface of the tube and propagate both inwards and laterally. A new technique was researched for detection of defects using a continuous-wave radar method within metal tubing. The experimental program resulted in a completed product development schedule and the design of an experimental apparatus for studying handling of the probe and data acquisition. These tests were completed as far as the prototypical probe performance allowed. The prototype probe design did not have sufficient sensitivity to detect a defect signal using the defined radar technique and did not allow successful completion of all of the project milestones. The best results from the prototype probe could not detect a tube defect using the radar principle. Though a more precision probe may be possible, the cost of design and construction was beyond the scope of the project. This report describes the probe development and the status of the design at the termination of the project.

  8. On the role of the Knudsen number with respect to heat transfer in micro-scale flows

    SciTech Connect (OSTI)

    Baker, J.; Calvert, M.E.; Power, D.J.; Chen, E.T. [Univ. of Alabama, Birmingham, AL (United States). Dept. of Materials and Mechanical Engineering; Ramalingam, M.L. [Universal Energy Systems, Inc., Dayton, OH (United States); Lamp, T.R. [Wright Lab., Wright-Patterson AFB, OH (United States)

    1996-12-31T23:59:59.000Z

    Advances in microelectronics and in microelectromechanical systems have resulted in devices with characteristic lengths approaching that of the molecular mean free path of gases. In certain applications, it has been proposed that gaseous flows be used to cool such devices. Prior research has revealed a fundamental lack of knowledge regarding the behavior of such micro-flows. The primary dimensionless parameter associated with gaseous micro-scale transport is the Knudsen number. A critical examination of the effects of an increasing Knudsen number on heat and momentum transfer characteristics of gaseous micro-flows is presented. The importance of thermal radiation, accurate thermophysical property models, and the introduction of higher order constitutive relations, i.e., the Burnett relations, are also discussed in relation to micro-flows. Conclusions are drawn regarding the relative importance of each of the above topics.

  9. Next Generation Nuclear Plant Intermediate Heat Exchanger Materials Research and Development Plan (PLN-2804)

    SciTech Connect (OSTI)

    J. K. Wright

    2008-04-01T23:59:59.000Z

    DOE has selected the High Temperature Gas-cooled Reactor (HTGR) design for the Next Generation Nuclear Plant (NGNP) Project. The NGNP will demonstrate the use of nuclear power for electricity and hydrogen production. It will have an outlet gas temperature in the range of 900įC and a plant design service life of 60 years. The reactor design will be a graphite moderated, helium-cooled, prismatic or pebble-bed reactor and use low-enriched uranium, Tri-Isotopic (TRISO)-coated fuel. The plant size, reactor thermal power, and core configuration will ensure passive decay heat removal without fuel damage or radioactive material releases during accidents. The NGNP Materials Research and Development (R&D) Program is responsible for performing R&D on likely NGNP materials in support of the NGNP design, licensing, and construction activities. Todayís high-temperature alloys and associated ASME Codes for reactor applications are approved up to 760įC. However, some primary system components, such as the Intermediate Heat Exchanger (IHX) for the NGNP will require use of materials that can withstand higher temperatures. The thermal, environmental, and service life conditions of the NGNP will make selection and qualification of some high-temperature materials a significant challenge. Examples include materials for the core barrel and core internals, such as the control rod sleeves. The requirements of the materials for the IHX are among the most demanding. Selection of the technology and design configuration for the NGNP must consider both the cost and risk profiles to ensure that the demonstration plant establishes a sound foundation for future commercial deployments. The NGNP challenge is to achieve a significant advancement in nuclear technology while at the same time setting the stage for an economically viable deployment of the new technology in the commercial sector soon after 2020. A number of solid solution strengthened nickel based alloys have been considered for application in heat exchangers and core internals for the NGNP. The primary candidates are Inconel 617, Haynes 230, Incoloy 800H and Hastelloy XR. Based on the technical maturity, availability in required product forms, experience base, and high temperature mechanical properties all of the vendor pre-conceptual design studies have specified Alloy 617 as the material of choice for heat exchangers. Also a draft code case for Alloy 617 was developed previously. Although action was suspended before the code case was accepted by ASME, this draft code case provides a significant head start for achieving codification of the material. Similarly, Alloy 800H is the material of choice for control rod sleeves. In addition to the above listed considerations, Alloy 800H is already listed in the nuclear section of the ASME Code; although the maximum use temperature and time need to be increased.

  10. The interaction of flow, heat transfer, and free interfaces in an electron-beam vaporization system for metals

    SciTech Connect (OSTI)

    Westerberg, K.W. [Aspen Technology, Inc., Cambridge, MA (United States); McClelland, M.A. [Lawrence Livermore National Lab., CA (United States); Finlayson, B.A. [Univ. of Washington, Seattle, WA (United States)

    1994-11-01T23:59:59.000Z

    A numerical analysis is made of the liquid flow and energy transport in a system to vaporize metals. The energy from an electron beam heats metal confined in a water-cooled crucible. Metal vaporizes from a hot pool of circulating liquid which is surrounded by a shell of its own solid. Flow in the pool is strongly driven by temperature-induced buoyancy and capillary forces and is located in the transition region between laminar and turbulent flow. At high vaporization rates, the thrust of the departing vapor forms a trench at the beam impact site. A modified finite element method is used to calculate the flow and temperature fields coupled with the interface locations. The mesh is structured with spines that stretch and pivot as the interfaces move. The discretized equations are arranged in an {open_quotes}arrow{close_quotes} matrix and solved using the Newton-Raphson method. The electron-beam power and width are varied for cases involving the high-rate vaporization of aluminum. Attention is focused on the interaction of vaporization, liquid flow, and heat transport in the trench area.

  11. Analytical and Numerical Study of Joule Heating Effects on Electrokinetically Pumped Continuous Flow PCR Chips

    E-Print Network [OSTI]

    Le Roy, Robert J.

    Analytical and Numerical Study of Joule Heating Effects on Electrokinetically Pumped Continuous, and the potential for integration.1-3 Joule heating is inevitable when electrokinetic pumping is used Form: December 8, 2007 Joule heating is an inevitable phenomenon for microfluidic chips involving

  12. Gravitational collapse of a spherical star with heat flow as a possible energy mechanism of gamma-ray bursts

    E-Print Network [OSTI]

    Zhe Chang; Cheng-Bo Guan; Chao-Guang Huang; Xin Li

    2008-03-26T23:59:59.000Z

    We investigate the gravitational collapse of a spherically symmetric, inhomogeneous star, which is described by a perfect fluid with heat flow and satisfies the equation of state $p=\\rho/3$ at its center. In the process of the gravitational collapsing, the energy of the whole star is emitted into space. And the remaining spacetime is a Minkowski one without a remnant at the end of the process. For a star with a solar mass and solar radius, the total energy emitted is at the order of $10^{54}$ {\\rm erg}, and the time-scale of the process is about $8s$. These are in the typical values for a gamma-ray burst. Thus, we suggest the gravitational collapse of a spherical star with heat flow as a possible energy mechanism of gamma-ray bursts.

  13. Columbia University flow instability experimental program: Volume 2. Single tube uniformly heated tests -- Part 2: Uncertainty analysis and data

    SciTech Connect (OSTI)

    Dougherty, T.; Maciuca, C.; McAssey, E.V. Jr.; Reddy, D.G.; Yang, B.W.

    1990-05-01T23:59:59.000Z

    In June 1988, Savannah River Laboratory requested that the Heat Transfer Research Facility modify the flow excursion program, which had been in progress since November 1987, to include testing of single tubes in vertical down-flow over a range of length to diameter (L/D) ratios of 100 to 500. The impetus for the request was the desire to obtain experimental data as quickly as possible for code development work. In July 1988, HTRF submitted a proposal to SRL indicating that by modifying a facility already under construction the data could be obtained within three to four months. In January 1990, HTFR issued report CU-HTRF-T4, part 1. This report contained the technical discussion of the results from the single tube uniformly heated tests. The present report is part 2 of CU-HTRF-T4 which contains further discussion of the uncertainty analysis and the complete set of data.

  14. Acoustically enhanced heat exchange and drying apparatus

    DOE Patents [OSTI]

    Bramlette, T. Tazwell (Livermore, CA); Keller, Jay O. (Oakland, CA)

    1989-01-01T23:59:59.000Z

    A heat transfer apparatus includes a first chamber having a first heat transfer gas inlet, a second heat transfer gas inlet, and an outlet. A first heat transfer gas source provides a first gas flow to the first chamber through the first heat transfer gas inlet. A second gas flow through a second chamber connected to the side of the first chamber, generates acoustic waves which bring about acoustical coupling of the first and second gases in the acoustically augmented first chamber. The first chamber may also include a material inlet for receiving material to be dried, in which case the gas outlet serves as a dried material and gas outlet.

  15. Heat transfer in a two-pass internally ribbed turbine blade coolant channel with cylindrical vortex generators

    SciTech Connect (OSTI)

    Hibbs, R.; Chen, Y.; Nikitopoulos, D. [Louisiana State Univ., Baton Rouge, LA (United States)] [and others

    1995-10-01T23:59:59.000Z

    The effect of vortex generators on the mass (heat) transfer from the ribbed passage of a two pass turbine blade coolant channel is investigated with the intent of optimizing the vortex generator geometry so that significant enhancements in mass/heat transfer can be achieved. In the experimental configuration considered, ribs are mounted on two opposite walls; all four walls along each pass are active and have mass transfer from their surfaces but the ribs are non-participating. Mass transfer measurements, in the form of Sherwood number ratios, are made along the centerline and in selected inter-rib modules. Results are presented for Reynolds number in the range of 5,000 to 40,000, pitch to rib height ratios of 10.5 and 21, and vortex generator-rib spacing to rib height ratios of 0.55, and 1.5. Centerline and spanwise averaged Sherwood number ratios are presented along with contours of the Sherwood number ratios. Results indicate that the vortex generators induce substantial increases in the local mass transfer rates, particularly along the side walls, and modest increases in the average mass transfer rates. The vortex generators have the effect of making the inter-rib profiles along the ribbed walls more uniform. Along the side walls, horse-shoe vortices that characterize the vortex generator wake are associated with significant mass transfer enhancements. The wake effects and the levels of enhancement decrease somewhat with increasing Reynolds number and decreasing pitch.

  16. Heat transfer in a two-pass internally ribbed turbine blade coolant channel with cylindrical vortex generators

    SciTech Connect (OSTI)

    Hibbs, R.; Acharya, S.; Chen, Y. [Louisiana State Univ., Baton Rouge, LA (United States)] [and others

    1995-12-31T23:59:59.000Z

    The effect of vortex generators on the mass (heat) transfer from the ribbed passage of a two pass turbine blade coolant channel is investigated with the intent of optimizing the vortex generator geometry so that significant enhancements in mass/heat transfer can be achieved. In the experimental configuration considered, ribs are mounted on two opposite walls; all four walls along each pass are active and have mass transfer from their surfaces but the ribs are non-participating. Mass transfer measurements, in the form of Sherwood number ratios, are made along the centerline and in selected inter-rib modules. Results are presented for Reynolds number in the range of 5,000 to 40,000, pitch to rib height ratios of 10.5 and 21, and vortex generator-rib spacing to rib height ratios of 0.55, and 1.5. Centerline and spanwise averaged Sherwood number ratios are presented along with contours of the Sherwood number ratios. Results indicate that the vortex generators induce substantial increases in the local mass transfer rates, particularly along the side walls, and modest increases in the average mass transfer rates. The vortex generators have the effect of making the inter-rib profiles along the ribbed walls more uniform. Along the side walls, horse-shoe vortices that characterize the vortex generator wake are associated with significant mass transfer enhancements. The wake effects and the levels of enhancement decrease somewhat with increasing Reynolds number and decreasing pitch.

  17. Heat transfer in a two-pass internally ribbed turbine blade coolant channel with cylindrical vortex generators

    SciTech Connect (OSTI)

    Hibbs, R.G.; Acharya, S.; Chen, Y.; Nikitopoulos, D.E.; Myrum, T.A. [Louisiana State Univ., Baton Rouge, LA (United States). Mechanical Engineering Dept.

    1998-07-01T23:59:59.000Z

    The effect of vortex generators on the mass (heat) transfer from the ribbed passage of a two-pass turbine blade coolant channel is investigated with the intent of optimizing the vortex generator geometry so that significant enhancements in mass/heat transfer can be achieved. In the experimental configuration considered, ribs are mounted on two opposite walls; all four walls along each pass are active and have mass transfer from their surfaces but the ribs are nonparticipating. Mass transfer measurements, in the form of Sherwood number ratios, are made along the centerline and in selected interrib modules. Results are presented for Reynolds number in the range of 5000 to 40,000 pitch to rib height ratios of 10.5 and 21, and vortex generator-rib spacing to rib height ratios of 0.55 and 1.5. Centerline and spanwise-averaged Sherwood number ratios are presented along with contours of the Sherwood number ratios. Results indicate that the vortex generators lead to substantial increases in the local mass transfer rates, particularly along the side walls, and modest increases in the average mass transfer rates. The vortex generators have the effect of making the interrib profiles along the ribbed walls more uniform. Along the side walls, vortices that characterize the vortex generator wake are associated with significant mass transfer enhancements. The wake effects and the levels of enhancement decrease somewhat with increasing Reynolds number and decreasing pitch.

  18. Turbidity current flow over an obstacle and phases of sediment wave generation

    E-Print Network [OSTI]

    Strauss, Moshe

    2011-01-01T23:59:59.000Z

    We study the flow of particle-laden turbidity currents down a slope and over an obstacle. A high-resolution 2D computer simulation model is used, based on the Navier-Stokes equations. It includes poly-disperse particle grain sizes in the current and substrate. Particular attention is paid to the erosion and deposition of the substrate particles, including application of an active layer model. Multiple flows are modeled from a lock release that can show the development of sediment waves (SW). These are stream-wise waves that are triggered by the increasing slope on the downstream side of the obstacle. The initial obstacle is completely erased by the resuspension after a few flows leading to self consistent and self generated SW that are weakly dependant on the initial obstacle. The growth of these waves is directly related to the turbidity current being self sustaining, that is, the net erosion is more than the net deposition. Four system parameters are found to influence the SW growth: (1) slope, (2) current ...

  19. Modeling and experiments on differential pumping in linear plasma generators operating at high gas flows

    SciTech Connect (OSTI)

    Eck, H. J. N. van; Koppers, W. R.; Rooij, G. J. van; Goedheer, W. J.; Cardozo, N. J. Lopes; Kleyn, A. W. [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Engeln, R.; Schram, D. C. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

    2009-03-15T23:59:59.000Z

    The direct simulation Monte Carlo (DSMC) method was used to investigate the efficiency of differential pumping in linear plasma generators operating at high gas flows. Skimmers are used to separate the neutrals from the plasma beam, which is guided from the source to the target by a strong axial magnetic field. In this way, the neutrals are prevented to reach the target region. The neutral flux to the target must be lower than the plasma flux to enable ITER relevant plasma-surface interaction (PSI) studies. It is therefore essential to control the neutral gas dynamics. The DSMC method was used to model the expansion of a hot gas in a low pressure vessel where a small discrepancy in shock position was found between the simulations and a well-established empirical formula. Two stage differential pumping was modeled and applied in the linear plasma devices Pilot-PSI and PLEXIS. In Pilot-PSI a factor of 4.5 pressure reduction for H{sub 2} has been demonstrated. Both simulations and experiments showed that the optimum skimmer position depends on the position of the shock and therefore shifts for different gas parameters. The shape of the skimmer has to be designed such that it has a minimum impact on the shock structure. A too large angle between the skimmer and the forward direction of the gas flow leads to an influence on the expansion structure. A pressure increase in front of the skimmer is formed and the flow of the plasma beam becomes obstructed. It has been shown that a skimmer with an angle around 53 deg. gives the best performance. The use of skimmers is implemented in the design of the large linear plasma generator Magnum-PSI. Here, a three stage differentially pumped vacuum system is used to reach low enough neutral pressures near the target, opening a door to PSI research in the ITER relevant regime.

  20. Alternatives Generation and Analysis for Heat Removal from High Level Waste Tanks

    SciTech Connect (OSTI)

    WILLIS, W.L.

    2000-06-15T23:59:59.000Z

    This document addresses the preferred combination of design and operational configurations to provide heat removal from high-level waste tanks during Phase 1 waste feed delivery to prevent the waste temperature from exceeding tank safety requirement limits. An interim decision for the preferred method to remove the heat from the high-level waste tanks during waste feed delivery operations is presented herein.

  1. General-purpose heat source: Research and development program. Radioisotope thermoelectric generator impact tests: RTG-1 and RTG-2

    SciTech Connect (OSTI)

    Reimus, M.A.H.; Hinckley, J.E.; George, T.G.

    1996-07-01T23:59:59.000Z

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. The first two RTG Impact Tests were designed to provide information on the response of a fully loaded RTG to end-on impact against a concrete target. The results of these tests indicated that at impact velocities up to 57 m/s the converter shell and internal components protect the GPHS capsules from excessive deformation. At higher velocities, some of the internal components of the RTG interact with the GPHS capsules to cause excessive localized deformation and failure.

  2. General-purpose heat source: Research and development program, radioisotope thermoelectric generator/thin fragment impact test

    SciTech Connect (OSTI)

    Reimus, M.A.H.; Hinckley, J.E.

    1996-11-01T23:59:59.000Z

    The general-purpose heat source provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system. The results of this test indicated that impact by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the converter housing, failure of one fueled clad, and release of a small quantity of fuel.

  3. Energy Efficient Process Heating: Managing Air Flow Kevin Carpenter and Kelly Kissock

    E-Print Network [OSTI]

    Kissock, Kelly

    temperature and decreased combustion gas mass flow rate. The method for calculating savings from preheating flow include minimizing combustion air, preheating combustion air, minimizing ventilation air from minimizing combustion air accounts for improvement in efficiency from increased combustion

  4. Study on the heat transfer of heat exchangers for the Stirling Engine

    SciTech Connect (OSTI)

    Kanzaka, M. (Nagasaki Research and Development Center (JP)); Iwabuchi, M. (Advanced Technology Research Center, Mitsubishi Heavy Industries, Ltd. (JP))

    1991-01-01T23:59:59.000Z

    This paper reports that heat-transfer characteristics in heated tubes under periodically reversing flow conditions have been investigated experimentally using a test apparatus that simulates the heat exchangers for the actual Sterling engine. It was shown that the heat-transfer characteristics under these conditions were greatly affected by the piston phase-angle difference that generates the reversing flow of the working gas, and this phenomenon was proper to the heat transfer under the periodically reversing flow and was different from conventional heat transfer in steady flow. The experimental correlation considering the influence of the piston phase-angle difference for the heat-transfer coefficient has been induced by the use of the working gas velocity evaluated from the Schmidt cycle model which is one of the ideal Sterling cycles.

  5. Research Note on a Parabolic Heat-Balance Integral Method with Unspecified Exponent: An Entropy Generation Approach in Optimal Profile Determination

    E-Print Network [OSTI]

    Jordan Hristov

    2010-12-12T23:59:59.000Z

    The heat-balance integral method of Goodman is studied with two simple 1-D heat conduction problems with prescribed temperature and flux boundary conditions. These classical problems with well known exact solutions enable to demonstrate the heat-balance integral method performance by a parabolic profile and the entropy generation minimization concept in definition of the appropriate profile exponent. The basic assumption generating the additional constraints needed to perform the solution is based on the requirement to minimize the difference in the local thermal entropy generation rates calculated by the approximate and the exact profile, respectively. This concept is easily applicable since the general concept has simple implementation of the condition requiring the thermal entropy generations calculated through both profiles to be the same at the boundary. The entropy minimization generation approach automatically generates the additional requirement which is deficient in the set of conditions defined by the heat-balance integral method concept.

  6. FRACSTIM/I: A Fully Coupled Fluid Flow/Heat Transport and Geomechanica...

    Broader source: Energy.gov (indexed) [DOE]

    Using Solid Particles as Heat Transfer Fluid for use in Concentrating Solar Power (CSP) Plants Coupled Thermal-Hydrological-Mechanical-Chemical Model And Experiments For...

  7. Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01T23:59:59.000Z

    dual compressor available on the market Compared with the selected building, a more energy efficient building will have lower space cooling and heating

  8. Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01T23:59:59.000Z

    heat pump, and the energy consumption of the whole GSHP system given the accurate information of the building, GSHP system, weather data,

  9. Heat transfer and flow characteristics of cooling channels in turbine blades

    E-Print Network [OSTI]

    Saxena, Amit

    1988-01-01T23:59:59.000Z

    /mass transfer distributions were determined for straight flow' through a pin fin channel (H/D = 1, S/D = X/D = 2. 5) and a flow through the pin fin channel with trailing edge flow ejection. The overall friction factor and local pressure drop results were... obtained for various configurations and lengths (L/d = 2 and 20) of the trailing edge ejection holes, From the pressure drop data, the radial mass flow rate and the mass flow rates through trailing edge ejection holes were calculated. The results show...

  10. Sulfur Based Thermochemical Heat Storage for Baseload Concentrated Solar Power Generation

    SciTech Connect (OSTI)

    wong, bunsen

    2014-11-20T23:59:59.000Z

    This project investigates the engineering and economic feasibility of supplying baseload power using a concentrating solar power (CSP) plant integrated with sulfur based thermochemical heat storage. The technology stores high temperature solar heat in the chemical bonds of elemental sulfur. Energy is recovered as high temperature heat upon sulfur combustion. Extensive developmental and design work associated with sulfur dioxide (SO2) disproportionation and sulfuric acid (H2SO4) decomposition chemical reactions used in this technology had been carried out in the two completed phases of this project. The feasibility and economics of the proposed concept was demonstrated and determined.

  11. Establishment of a research facility for investigating the effects of unsteady inlet flow, pressure gradient and curvature on boundary layer development, wake development and heat transfer

    E-Print Network [OSTI]

    Pardivala, Darayus Noshir

    1991-01-01T23:59:59.000Z

    ESTABLISHMENT OF A RESEARCH FACILITY FOR INVESTIGATING THE EFFECTS OF UNSTEADY INLET FLOW) PRESSURE GRADIENT AND CURVATURE ON BOUNDARY LAYER DEVELOPMENT) %'AKE DEVELOPMENT AND HEAT TRANSFER A Thesis by DARAYUS NOSHIR PARDIVALA Submitted... THE EFFECTS OF UNSTEADY INLET FLOW, PRESSURE GRADIENT AND CURVATURE ON BOUNDARY LAYER DEVELOPMENT, WAKE DEVELOPMENT AND HEAT TRANSFER A Thesis by DARAYUS NOSHIR PARDIVALA Approved as to style and content by: Taher Schobeiri (Chair of Committee) Gerald...

  12. Second generation ground coupled solar assisted heat pump systems. Six month progress report

    SciTech Connect (OSTI)

    Rhodes, G W; Backlund, J C; Helm, J M

    1981-01-01T23:59:59.000Z

    Progress is reported on an investigation of the technical and commercial viability of a novel ground coupled, solar assisted heat pump system for residential space heating and cooling applications. Specific areas of study are solar collector/heat rejector performance, flat plate earth heat exchanger performance, system performance simulations, and commercialization and marketing analysis. Collector/rejector performance, determined by various thermal experiments, is discussed. The design and construction of an experimental site to study ground coupling is discussed. Theoretical analysis is also presented. The performance of the GCSAHP system and conventional alternatives, as determined by simple computer models, is presented and discussed. Finally, the commercial viability of this unique space conditioning system is examined.

  13. Int. Symp. on Heat Transfer in Gas Turbine Systems 9 14 August, 2009, Antalya, Turkey

    E-Print Network [OSTI]

    Camci, Cengiz

    for turbine aero heat transfer work performed under rotational conditions. A flow coefficient and a loading candidates to generate very realistic gas turbine heat transfer data, the initial investment made generate an accurately measurable amount of heat transfer from the gas side to turbine blades in a linear

  14. FLOWS AND MOTIONS IN MOSS IN THE CORE OF A FLARING ACTIVE REGION: EVIDENCE FOR STEADY HEATING

    SciTech Connect (OSTI)

    Brooks, David H.; Warren, Harry P., E-mail: dhbrooks@ssd5.nrl.navy.mi [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2009-09-20T23:59:59.000Z

    We present new measurements of the time variability of intensity, Doppler, and nonthermal velocities in moss in an active region core observed by the EUV Imaging Spectrometer on Hinode in 2007 June. The measurements are derived from spectral profiles of the Fe XII 195 A line. Using the 2'' slit, we repeatedly scanned 150'' by 150'' in a few minutes. This is the first time it has been possible to make such velocity measurements in the moss, and the data presented are the highest cadence spatially resolved maps of moss Doppler and nonthermal velocities ever obtained in the corona. The observed region produced numerous C- and M-class flares with several occurring in the core close to the moss. The magnetic field was therefore clearly changing in the active region core, so we ought to be able to detect dynamic signatures in the moss if they exist. Our measurements of moss intensities agree with previous studies in that a less than 15% variability is seen over a period of 16 hr. Our new measurements of Doppler and nonthermal velocities reveal no strong flows or motions in the moss, nor any significant variability in these quantities. The results confirm that moss at the bases of high temperature coronal loops is heated quasi-steadily. They also show that quasi-steady heating can contribute significantly even in the core of a flare productive active region. Such heating may be impulsive at high frequency, but if so it does not give rise to large flows or motions.

  15. Analysis of fluid flow and heat transfer in a rib grit roughened surface solar air heater using CFD

    SciTech Connect (OSTI)

    Karmare, S.V. [Department of Mechanical Engineering, Government College Engineering, Karad 415 124, Maharashtra (India); Shivaji University, Kolhapur, Maharashtra (India); Tikekar, A.N. [Department of Mechanical Engineering, Walchand College of Engineering, Sangli (India); Shivaji University, Kolhapur, Maharashtra (India)

    2010-03-15T23:59:59.000Z

    This paper presents the study of fluid flow and heat transfer in a solar air heater by using Computational Fluid Dynamics (CFD) which reduces time and cost. Lower side of collector plate is made rough with metal ribs of circular, square and triangular cross-section, having 60 inclinations to the air flow. The grit rib elements are fixed on the surface in staggered manner to form defined grid. The system and operating parameters studied are: e/D{sub h} = 0.044, p/e = 17.5 and l/s = 1.72, for the Reynolds number range 3600-17,000. To validate CFD results, experimental investigations were carried out in the laboratory. It is found that experimental and CFD analysis results give the good agreement. The optimization of rib geometry and its angle of attack is also done. The square cross-section ribs with 58 angle of attack give maximum heat transfer. The percentage enhancement in the heat transfer for square plate over smooth surface is 30%. (author)

  16. Manufacture and properties of continuous grain flow crankshafts for locomotive and power generation diesel engines

    SciTech Connect (OSTI)

    Antos, D.J.; Nisbett, E.G. [National Forge Co., Irvine, PA (United States)

    1997-12-31T23:59:59.000Z

    The bulk of the large crankshaft production volume is associated with the medium speed diesel engine market. These engines have seen intense development to obtain higher power outputs without change in the physical size of the crankshaft and at the same time there has been continuing pressure to reduce costs. Fatigue and bearing normal wear are the major technical hurdles that threaten the crankshaft life, and measures for dealing with these issues are described. Continuous grain flow (CGF) crankshafts are responsible for the continued integrity of these enhanced power output engines and the production of these crankshafts is described. Comparisons are made with the older slab forging crankshaft production method. The demand for the medium speed diesel engine and its natural gas derivative is strong and supports an aggressive engine building industry serving locomotive, marine and power generation markets. This demand in turn relies on practical national standards that serve the needs of the engine builder, material supplier and the end user.

  17. Effervescent heating: constraints from nearby cooling flow clusters observed with XMM-Newton

    E-Print Network [OSTI]

    Rocco Piffaretti; Jelle Kaastra

    2006-05-15T23:59:59.000Z

    We have used deprojected radial density and temperature profiles of a sample of 16 nearby CF clusters observed with XMM-Newton to test whether the effervescent heating model can satisfactorily explain the dynamics of CF clusters. For each cluster we derived the required extra heating as a function of cluster-centric distance for various values of the unknown parameters $\\dot M$ (mass deposition rate) and $f_c$ (conduction efficiency). We fitted the extra heating curve using the AGN effervescent heating function and derived the AGN parameters $L$ (the time-averaged luminosity) and $r_0$ (the scale radius where the bubbles start rising in the ICM). While we do not find any solution with the effervescent heating model for only one object, we do show that AGN and conduction heating are not cooperating effectively for half of the objects in our sample. For most of the clusters we find that, when a comparison is possible, the derived AGN scale radius $r_0$ and the observed AGN jet extension have the same order of magnitude. The AGN luminosities required to balance radiative losses are substantially lowered if the fact that the AGN deposits energy within a finite volume is taken into account. For the Virgo cluster, we find that the AGN power derived from the effervescent heating model is in good agreement with the observed jet power.

  18. Influence of surface heating on the boundary layer stability of flows with favorable pressure gradients

    E-Print Network [OSTI]

    Landrum, David Brian

    1986-01-01T23:59:59.000Z

    $ of its chord heated to about 1. 5 times the adiabatic temperature. Compared to the adiabatic case, the nose heating slightly delayed the initial amplification of disturbances and significantly incr eased the transition length. A vertical traverse... . . . . 10 Fig. 3 Neutral stability cur ve f' or a typical boundar y layer velocity profile 13 Fig. 4a Falkner-Skan velocity profiles with wall heating, 8 0. 0 18 Fig. 4b Falkner-Skan temperature profiles, B=O. O 19 Fig. 5a Falkner-Skan velocity prof...

  19. TESTING THE ACCRETION FLOW WITH PLASMA WAVE HEATING MECHANISM FOR SAGITTARIUS A* BY THE 1.3 mm VLBI MEASUREMENTS

    SciTech Connect (OSTI)

    Huang Lei [Key Laboratory for Research in Galaxies and Cosmology, The University of Sciences and Technology of China, Chinese Academy of Sciences, Hefei 230026 (China); Takahashi, Rohta [Institute of Physical and Chemical Research, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Shen Zhiqiang, E-mail: mlhuang@ustc.edu.c [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030 (China)

    2009-12-01T23:59:59.000Z

    The vicinity of the supermassive black hole associated with the compact radio source Sagittarius (Sgr) A* is believed to dominate the observed emission at wavelengths near and shorter than approx1 millimeter. We show that a general relativistic accretion flow, heated via the plasma wave heating mechanism, is consistent with the polarization and recent millimeter-VLBI observations of Sgr A* for an inclination angle of approx45{sup 0}, position angle of approx140{sup 0}, and spin approx<0.9. Structure in visibilities produced by the black hole shadow can potentially be observed by 1.3 mm-VLBI on the existing Hawaii-CARMA and Hawaii-SMT baselines. We also consider eight additional potential millimeter-VLBI stations, including sites in Chile and New Zealand, finding that with these the basic geometry of the emission region can be reliably estimated.

  20. Shear flow generation and energetics in electromagnetic turbulence V. Naulin, A. Kendl, O. E. Garcia, A. H. Nielsen, and J. Juul Rasmussen

    E-Print Network [OSTI]

    Shear flow generation and energetics in electromagnetic turbulence V. Naulin, A. Kendl, O. E generation mechanisms via the Reynolds stress, Maxwell stress, and geodesic acoustic mode (GAM) transfer of mechanisms for the generation of shear flows connected to the low- to high confinement (LH-) transition have

  1. Directed motion generated by heat bath nonlinearly driven by external noise

    E-Print Network [OSTI]

    Jyotipratim Ray Chaudhuri; Debashis Barik; Suman Kumar Banik

    2007-11-02T23:59:59.000Z

    Based on the system heat bath approach where the bath is nonlinearly modulated by an external Gaussian random force, we propose a new microscopic model to study directed motion in the overdamped limit for a nonequilibrium open system. Making use of the coupling between the heat bath and the external modulation as a small perturbation we construct a Langevin equation with multiplicative noise and space dependent dissipation and the corresponding Fokker-Planck-Smoluchowski equation in the overdamped limit. We examine the thermodynamic consistency condition and explore the possibility of observing a phase induced current as a consequence of state dependent diffusion and, necessarily, nonlinear driving of the heat bath by the external noise.

  2. Finite element analysis of conjugate heat transfer in axisymmetric pipe flows

    E-Print Network [OSTI]

    Fithen, Robert Miller

    1987-01-01T23:59:59.000Z

    Temperature Page 43 se NOMENCLATURE specific heat of fluid at constant pressure variational operator test function dimensionless pipe thickness (t/R) non ? dimensional axial coordinate surface traction matrix Ky M?. nr Pe Sue!i wall...

  3. Urban Sewage Delivery Heat Transfer System (1): Flow Resistance and Energy Analysis

    E-Print Network [OSTI]

    Zhang, C.; Wu, R.; Li, G.; Li, X.; Huang, L.; Sun, D.

    2006-01-01T23:59:59.000Z

    The thimble delivery heat-transfer (TDHT) system is one of the primary modes to utilize the energy of urban sewage. Given the schematic diagram of TDHT system, introducing the definition of equivalent fouling roughness height, and using the Niklaus...

  4. TURBULENT HEATING OF THE DISTANT SOLAR WIND BY INTERSTELLAR PICKUP PROTONS IN A DECELERATING FLOW

    E-Print Network [OSTI]

    Isenberg, Philip A.

    Previous models of solar wind heating by interstellar pickup proton-driven turbulence have assumed that the wind speed is a constant in heliocentric radial position. However, the same pickup process, which is taken to ...

  5. The flow structure under mixed convection in a uniformly heated vertical pipe

    E-Print Network [OSTI]

    Lee, Jeongik

    2005-01-01T23:59:59.000Z

    For decay heat removal systems in the conceptual Gas-cooled Fast Reactor (GFR) currently under development, passive emergency cooling using natural circulation of a gas at an elevated pressure is being considered. Since ...

  6. Alumina Nanoparticle Pre-coated Tubing Ehancing Subcooled Flow Boiling Cricital Heat Flux

    E-Print Network [OSTI]

    Truong, Bao H.

    Nanofluids are engineered colloidal dispersions of nano-sized particle in common base fluids. Previous pool boiling studies have shown that nanofluids can improve critical heat flux (CHF) up to 200% for pool boiling and ...

  7. NEXT GENERATION COMMERCIAL HEAT PUMPWATER HEATER USING CARBON DIOXIDE USING DIFFERENT IMPROVEMENT APPROACHES

    SciTech Connect (OSTI)

    Chad Bowers; Michael Petersen; Stefan Elbel; Pega Hrnjak

    2012-04-01T23:59:59.000Z

    Although heat pump water heaters are today widely accepted in Japan, where energy costs are high and government incentives for their use exist, acceptance of such a product in the U.S. has been slow. This trend is slowly changing with the introduction of heat pump water heaters into the residential market, but remains in the commercial sector. Barriers to heat pump water heater acceptance in the commercial market have historically been performance, reliability and first/operating costs. The use of carbon dioxide (R744) as the refrigerant in such a system can improve performance for relatively small increase in initial cost and make this technology more appealing. What makes R744 an excellent candidate for use in heat pump water heaters is not only the wide range of ambient temperatures within which it can operate, but also the excellent ability to match water to refrigerant temperatures on the high side, resulting in very high exit water temperatures of up to 82√?¬ļC, as required by sanitary codes in the U.S. (Food Code, 2005), in a single pass, temperatures that are much more difficult to reach with other refrigerants. This can be especially attractive in applications where this water is used for the purpose of sanitation. While reliability has also been of concern historically, dramatic improvements have been made over the last several years through research done in the automotive industry and commercialization of R744 technology in residential water heating mainly in Japan. This paper presents the performance results from the development of an R744 commercial heat pump water heater of approximately 35 kW and a comparison to a baseline R134a unit of the same capacity and footprint. In addition, recommendations are made for further improvements of the R744 system which could result in possible energy savings of up to 20 %.

  8. The Difficulty of the Heating of Cluster Cooling Flows by Sound Waves and Weak Shocks

    E-Print Network [OSTI]

    Yutaka Fujita; Takeru Ken Suzuki

    2006-10-23T23:59:59.000Z

    We investigate heating of the cool core of a galaxy cluster through the dissipation of sound waves and weak shocks excited by the activities of the central active galactic nucleus (AGN). Using a weak shock theory, we show that this heating mechanism alone cannot reproduce observed temperature and density profiles of a cluster, because the dissipation length of the waves is much smaller than the size of the core and thus the wave energy is not distributed to the whole core.

  9. Electrically heated DPF start-up strategy

    DOE Patents [OSTI]

    Gonze, Eugene V [Pinckney, MI; Ament, Frank [Troy, MI

    2012-04-10T23:59:59.000Z

    An exhaust system that processes exhaust generated by an engine has a diesel particulate filter (DPF) that is disposed downstream of the engine and that filters particulates in the exhaust. An electrical heater is disposed upstream of the DPF and selectively heats the exhaust to initiate combustion of the particulates. Heat generated by combustion of particulates in the heater induces combustion of particulates within the DPF. A control module selectively enables current flow to the electrical heater for an initial period of a DPF regeneration cycle, and limits exhaust flow while the electrical heater is heating to a predetermined soot combustion temperature.

  10. Continuous-Wave Radar to Detect Defects Within Heat Exchangers and Steam Generator Tubes ; Revised September 3, 2003

    SciTech Connect (OSTI)

    Gary E. Rochau and Thurlow W.H. Caffey, Sandia National Laboratories, Albuquerque, NM 87185-0740; Bahram Nassersharif and Gabe V. Garcia, Department of Mechanical Engineering, New Mexico State University, Las Cruces, NM 88003-8001; Russell P. Jedlicka, Klipsch School of Electrical and Computer Engineering, New Mexico State University, Las Cruces, NM 88003-8001

    2003-05-01T23:59:59.000Z

    OAK B204 Continuous-Wave Radar to Detect Defects Within Heat Exchangers and Steam Generator Tubes ; Revised September 3, 2003. A major cause of failures in heat exchangers and steam generators in nuclear power plants is degradation of the tubes within them. The tube failure is often caused by the development of cracks that begin on the outer surface of the tube and propagate both inwards and laterally. A new technique was researched for detection of defects using a continuous-wave radar method within metal tubing. The technique is 100% volumetric, and may find smaller defects, more rapidly, and less expensively than present methods. The project described in this report was a joint development effort between Sandia National Laboratories (SNL) and New Mexico State University (NMSU) funded by the US Department of Energy. The goal of the project was to research, design, and develop a new concept utilizing a continuous wave radar to detect defects inside metallic tubes and in particular nuclear plant steam generator tubing. The project was divided into four parallel tracks: computational modeling, experimental prototyping, thermo-mechanical design, and signal detection and analysis.

  11. Method and apparatus for fuel gas moisturization and heating

    DOE Patents [OSTI]

    Ranasinghe, Jatila (Niskayuna, NY); Smith, Raub Warfield (Ballston Lake, NY)

    2002-01-01T23:59:59.000Z

    Fuel gas is saturated with water heated with a heat recovery steam generator heat source. The heat source is preferably a water heating section downstream of the lower pressure evaporator to provide better temperature matching between the hot and cold heat exchange streams in that portion of the heat recovery steam generator. The increased gas mass flow due to the addition of moisture results in increased power output from the gas and steam turbines. Fuel gas saturation is followed by superheating the fuel, preferably with bottom cycle heat sources, resulting in a larger thermal efficiency gain compared to current fuel heating methods. There is a gain in power output compared to no fuel heating, even when heating the fuel to above the LP steam temperature.

  12. ESTIMATION OF OUTLET MASS FLOW FOR A MONO-TUBE CAVITY RECEIVER FOR DIRECT STEAM GENERATION

    E-Print Network [OSTI]

    contains recent developments on a dynamic heat transfer model for a mono-tube steam cavity boiler, which

  13. Chemical heat pump

    DOE Patents [OSTI]

    Greiner, Leonard (2750-C Segerstrom Ave., Santa Ana, CA 92704)

    1980-01-01T23:59:59.000Z

    A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer. The heat pump part of the system heats or cools a house or other structure through a combination of evaporation and absorption or, conversely, condensation and desorption, in a pair of containers. A set of automatic controls change the system for operation during winter and summer months and for daytime and nighttime operation to satisfactorily heat and cool a house during an entire year. The absorber chamber is subjected to solar heating during regeneration cycles and is covered by one or more layers of glass or other transparent material. Daytime home air used for heating the home is passed at appropriate flow rates between the absorber container and the first transparent cover layer in heat transfer relationship in a manner that greatly reduce eddies and resultant heat loss from the absorbant surface to ambient atmosphere.

  14. Large-Eddy Simulation of Flow and Pollutant Transport in Urban Street Canyons with Ground Heating

    E-Print Network [OSTI]

    Li, Xian-Xiang

    Our study employed large-eddy simulation (LES) based on a one-equation subgrid-scale model to investigate the flow field and pollutant dispersion characteristics inside urban street canyons. Unstable thermal stratification ...

  15. Review of fluid flow and convective heat transfer within rotating disk cavities

    E-Print Network [OSTI]

    Boyer, Edmond

    -00975626,version1-8Apr2014 Author manuscript, published in "International Journal of Thermal Sciences 67 based on and r. Rej Jet Reynolds number based on W and D. ReU Cross-flow Reynolds number Ro Rossby

  16. A computational model for viscous fluid flow, heat transfer, and melting in in situ vitrification melt pools

    SciTech Connect (OSTI)

    McHugh, P.R.; Ramshaw, J.D.

    1991-11-01T23:59:59.000Z

    MAGMA is a FORTRAN computer code designed to viscous flow in in situ vitrification melt pools. It models three-dimensional, incompressible, viscous flow and heat transfer. The momentum equation is coupled to the temperature field through the buoyancy force terms arising from the Boussinesq approximation. All fluid properties, except density, are assumed variable. Density is assumed constant except in the buoyancy force terms in the momentum equation. A simple melting model based on the enthalpy method allows the study of the melt front progression and latent heat effects. An indirect addressing scheme used in the numerical solution of the momentum equation voids unnecessary calculations in cells devoid of liquid. Two-dimensional calculations can be performed using either rectangular or cylindrical coordinates, while three-dimensional calculations use rectangular coordinates. All derivatives are approximated by finite differences. The incompressible Navier-Stokes equations are solved using a new fully implicit iterative technique, while the energy equation is differenced explicitly in time. Spatial derivatives are written in conservative form using a uniform, rectangular, staggered mesh based on the marker and cell placement of variables. Convective terms are differenced using a weighted average of centered and donor cell differencing to ensure numerical stability. Complete descriptions of MAGMA governing equations, numerics, code structure, and code verification are provided. 14 refs.

  17. Effect of radiative heat transfer on the coagulation dynamics of combustion-generated particles

    SciTech Connect (OSTI)

    Mackowski, D.W. (Auburn Univ., AL (United States)); Tassopoulos, M.; Rosner, D.E. (Yale Univ., New Haven, CT (United States))

    1994-01-01T23:59:59.000Z

    We examine the influences of radiation heat transfer on the size and number density evolution of small coagulating particles. On a microscopic level, radiative emission and/or absorption by the particle will perturb the gas temperature field adjacent to each particle. As a result of thermophoretic particle transport, the nonequilibrium condition can alter the collision rates with neighboring particles. A simplified analysis of the thermophoretic coagulation mechanism suggests that net radiative cooling of the particles can lead to an accelerated growth of [mu]m-sized particles, whereas net radiative heating can act to essentially freeze coagulation rates. On the macroscopic level, the addition or removal of heat in the gas through radiative absorption emission by the particle cloud can also significantly alter, through thermophoretic transport, the local particle number density. Under certain cases these effects can augment the accelerated coagulation rates that occur under radiative cooling conditions. We also examine the particular situation of equilibrium between particle cloud radiative absorption and emission - which results in no net macroscopic effect on the gas. 30 refs., 9 figs.

  18. Direct containment heating and aerosol generation during high-pressure-melt expulsion experiments

    SciTech Connect (OSTI)

    Tarbell, W.W.; Brockmann, J.E.; Washington, K.E.; Pilch, M.; Marx, K.D.

    1988-01-01T23:59:59.000Z

    Severe nuclear plant accidents can involve the degradation of the reactor core while the primary coolant system remains pressurized. Molten fuel reaching the lower head of the reactor pressure vessel (RPV) may attack and fail the instrument guide tube penetrations, allowing the tube to be expelled from the vessel. The resulting aperture allows the molten fuel to be ejected into the cavity, followed by the blowdown of the contents of the primary system (high-pressure-melt ejection). Entrainment of the core debris in the cavity by the blowdown gases may cause high-temperature fuel particles to be carried into the containment building. Energy exchange between the particles and the atmosphere may cause heating and pressurizing of the containment (direct containment heating (DCH)). The complex phenomena associated with direct containment heating accident sequences are not well understood. This work describes a series of four experiments that have been performed to study and quantify the processes involved. The data from the experiments are used to guide the development of computer models to describe the response of containments under accident conditions.

  19. Numerical study of flow and heat transfer in 3D serpentine channels using colocated grids

    E-Print Network [OSTI]

    Chintada, Sailesh Raju

    1998-01-01T23:59:59.000Z

    the walls is held constant at a value of 40. 0 W/ms. The specification of this value is arbitrary and it does not change the Nusselt number (Nu), though the temperature field is dependent on it. However, in case of PDF heat transfer, the solution...

  20. Transient response of an industrial fin tube heat exchanger to flow variations

    E-Print Network [OSTI]

    Rana, Gopalji Motiram

    1967-01-01T23:59:59.000Z

    . Tho most impor ant assumptions made were that the proper- tiess Gl. t t e s Leais ar!d w, !ter and heat transfer coe f f ic ients for the stean! and water side did not vary with posi ion. l, spies: transform techniques were utilized to obtain the...

  1. Industrial Waste Heat Recovery Using Heat Pipes†

    E-Print Network [OSTI]

    Ruch, M. A.

    1981-01-01T23:59:59.000Z

    For almost a decade now, heat pipes with secondary finned surfaces have been utilized in counter flow heat exchangers to recover sensible energy from industrial exhaust gases. Over 3,000 such heat exchangers are now in service, recovering...

  2. Thermoelectric generator cooling system and method of control

    DOE Patents [OSTI]

    Prior, Gregory P; Meisner, Gregory P; Glassford, Daniel B

    2012-10-16T23:59:59.000Z

    An apparatus is provided that includes a thermoelectric generator and an exhaust gas system operatively connected to the thermoelectric generator to heat a portion of the thermoelectric generator with exhaust gas flow through the thermoelectric generator. A coolant system is operatively connected to the thermoelectric generator to cool another portion of the thermoelectric generator with coolant flow through the thermoelectric generator. At least one valve is controllable to cause the coolant flow through the thermoelectric generator in a direction that opposes a direction of the exhaust gas flow under a first set of operating conditions and to cause the coolant flow through the thermoelectric generator in the direction of exhaust gas flow under a second set of operating conditions.

  3. JOURNAL OF GEOPHYSICAL RESEARCH: SPACE PHYSICS, VOL. 118, 111, doi:10.1002/jgra.50558, 2013 100 days of ELF/VLF generation via HF heating with HAARP

    E-Print Network [OSTI]

    days of ELF/VLF generation via HF heating with HAARP M. B. Cohen1 and M. Golkowski2 Received 20 June Frequency Active Auroral Research Program (HAARP) facility near Gakona, Alaska, at a variety of ELF injected into the waveguide and reaching 250 km. The median power generated by HAARP and injected

  4. Columbia University Flow Instability Experimental Program, Volume 10: Critical Heat Flux Test Program data tables

    SciTech Connect (OSTI)

    Coutts, D.A.

    1993-09-01T23:59:59.000Z

    This report is one of a series of reports which document the flow instability testing conducted by Columbia University during 1989 through 1992. This report volume provides a hardcopy version of the twenty-six electronic media data files: CO515(A-D).DAT, CO525(A-G). DAT, CO530(A-K).DAT, CO718(A-E).DAT.

  5. Transient fluid and heat flow modeling in coupled wellbore/reservoir systems

    E-Print Network [OSTI]

    Izgec, Bulent

    2009-05-15T23:59:59.000Z

    ....................................................... 66 5.3.1 Modeling Field Data ..................................................................... 68 5.3.2 Optimal Location of Permanent Downhole Gauge....................... 71 5.4 Effect of Gauge Location on Pressure-Transient Analysis... at the midpoint of the flow string................................. 70 Figure 5.26 Downhole gauge placement configurations .............................................. 71 Figure 5.27 Temperature and density profiles in the wellbore...

  6. Momentum and heat fluxes in a turbulent air flow over a wet, smooth boundary

    E-Print Network [OSTI]

    Rice, Warren

    1958-01-01T23:59:59.000Z

    Idealized sketch, of boundary layer flow regions................ .............45 Figure 2 Schematic diagram of wind tunnel. . . . 46 Figure 3 Photograph of wind tunnel............ .. 47 Figure 4 Photograph of wind tunnel............ .. 47 Figure 5... mechanism and probe.................. .. 49 Figure 9 Distances of interest in the momentum and thermal boundary layers ............ 50 Figure 10 A typical velocity and temperature profile comparison .................. .. 51 Figure 1 1 Variation...

  7. Spring temperatures in the Sagehen Basin, Sierra Nevada, CA: implications for heat flow and groundwater circulation

    E-Print Network [OSTI]

    Manga, Michael

    on groundwater flow depths within the basin. An analytical model based on these constraints indicates@berkeley.edu. Tel: +1 510 642 2288. Fax: +1 510 643 9980. Geofluids (2009) 9, 195­207 INTRODUCTION Groundwater and groundwater circulation MARIA BRUMM, CHI-YUEN WANG AND MICHAEL MANGA Earth and Planetary Science, University

  8. Temperatures, heat flow, and water chemistry from drill holes in the Raft River geothermal system, Cassia County, Idaho

    SciTech Connect (OSTI)

    Nathenson, M.; Urban, T.C.; Diment, W.H.; Nehring, N.L.

    1980-01-01T23:59:59.000Z

    The Raft River area of Idaho contains a geothermal system of intermediate temperatures (approx. = 150/sup 0/C) at depths of about 1.5 km. Outside of the geothermal area, temperature measurements in three intermediate-depth drill holes (200 to 400 m) and one deep well (1500 m) indicate that the regional conductive heat flow is about 2.5 ..mu..cal/cm/sup 2/ sec or slightly higher and that temperature gradients range from 50/sup 0/ to 60/sup 0/C/km in the sediments, tuffs, and volcanic debris that fill the valley. Within and close to the geothermal system, temperature gradients in intermediate-depth drill holes (100 to 350 m) range from 120/sup 0/ to more than 600/sup 0/C/km, the latter value found close to an artesian hot well that was once a hot spring. Temperatures measured in three deep wells (1 to 2 km) within the geothermal area indicate that two wells are in or near an active upflow zone, whereas one well shows a temperature reversal. Assuming that the upflow is fault controlled, the flow is estimated to be 6 liter/sec per kilometer of fault length. From shut-in pressure data and the estimated flow, the permeability times thickness of the fault is calculated to be 2.4 darcy m. Chemical analyses of water samples from old flowing wells, recently completed intermediate-depth drill holes, and deep wells show a confused pattern. Geothermometer temperatures of shallow samples suggest significant re-equilibration at temperatures below those found in the deep wells. Silica geothermometer temperatures of water samples from the deep wells are in reasonable agreement with measured temperatures, whereas Na-K-Ca temperatures are significantly higher than measured temperatures. The chemical characteristics of the water, as indicated by chloride concentration, are extremely variable in shallow and deep samples. Chloride concentrations of the deep samples range from 580 to 2200 mg/kg.

  9. Vorticity generation in creeping flow past a magnetic obstacle Centro de Investigacin en Energa, UNAM, Apartado Postal 34, Temixco, Morelos 62580, Mexico

    E-Print Network [OSTI]

    Abdou, Mohamed

    Vorticity generation in creeping flow past a magnetic obstacle S. Cuevas* Centro de Investigación Mechanical & Aerospace Engineering Department, UCLA, 44-114 Engineering IV, Los Angeles, California 90095 The generation of vorticity in the two-dimensional creeping flow of an incompressible, electrically conduct- ing

  10. Dealing with big circulation flow, small temperature difference based on verified dynamic model simulations of a hot water district heating system

    E-Print Network [OSTI]

    Zhong, L.

    2014-01-01T23:59:59.000Z

    DEALING WITH ďBIG CIRCULATION FLOW RATE, SMALL TEMPERATURE DIFFERENCEĒ BASED ON VERIFIED DYNAMIC MODEL SIMULATIONS OF A HOT WATER DISTRICT HEATING SYSTEM Li Lian Zhong, Senior Sales Consultant, Danfoss Automatic Controls Management (Shanghai...) Co.,Ltd, Anshan, China ABSTRACT Dynamic models of an indirect hot water district heating system were developed based on the first principle of thermodynamics. The ideal model was verified by using measured operational data. The ideal...

  11. Rotor bore and turbine rotor wheel/spacer heat exchange flow circuit

    DOE Patents [OSTI]

    Caruso, Philip M. (Selkirk, NY); Eldrid, Sacheverel Quentin (Saratoga Springs, NY); Ladhani, Azad A. (Niskayuna, NY); DeMania, Alan Richard (Niskayuna, NY); Palmer, Gene David (Clifton Park, NY); Wilson, Ian David (Clifton Park, NY); Rathbun, Lisa Shirley (Scotia, NY); Akin, Robert Craig (Schenectady, NY)

    2002-01-01T23:59:59.000Z

    In a turbine having closed-circuit steam-cooling passages about the rim of the rotor during steady-state operation, compressor discharge air is supplied to the rotor bore for passage radially outwardly into the wheel space cavities between the wheels and spacers. Communicating slots and channels in the spacers and wheels at circumferentially spaced positions enable egress of the compressor discharge air into the hot gas flow path. At turbine startup, cooling air flows through the closed-circuit steam passages to cool the outer rim of the rotor while compressor discharge air pre-warms the wheels and spacers. At steady-state, cooling steam is supplied in the closed-circuit steam-cooling passages and compressor discharge air is supplied through the bore and into the wheel space cavities to cool the rotor.

  12. Roll Wave Effects on Annular Condensing Heat Transfer in Horizontal PCCS Condenser Tube

    SciTech Connect (OSTI)

    Masaya Kondo; Hideo Nakamura; Yoshinari Anoda [Japan Atomic Energy Research Institute, Tokai-mura 319-1195 (Japan); Sadanori Saishu; Hiroyuki Obata; Rumi Shimada [Japan Atomic Power Company (Japan); Shinichi Kawamura [Tokyo Electric Power Company, Incorporated, 1-3, Uchisaiwai-cho 1-chome, Chiyoda-ku, Tokyo, 1008560 (Japan)

    2002-07-01T23:59:59.000Z

    A horizontal in-tube condensation heat exchanger is under investigation to be used for a passive containment cooling system (PCCS) of a next generation-type BWR. The flow conditions in the horizontal condenser tube were observed both visually and by local void fraction fluctuation. The observed flow regimes at a rated condition were annular flow at the tube inlet, and turned gradually into wavy flow and smooth stratified flow along the length of the tube. It was found further that frequency of the roll waves that appear on the liquid film in the annular flow is closely related to the measured local condensation heat transfer coefficient. Based on the flow observation, the roll wave frequency and measured condensation heat transfer coefficient, a model is proposed which predicts the condensation heat transfer coefficient particularly for annular flows around the tube inlet region. The proposed heat transfer model predicts well the influences of pressure, local gas-phase velocity and film thickness. (authors)

  13. New flow boiling heat transfer correlation for CFC-114 and C{sub 4}F{sub 10}

    SciTech Connect (OSTI)

    Szady, A.J. [Oak Ridge National Lab., TN (United States). Engineering Technology Div.

    1995-08-01T23:59:59.000Z

    The flow boiling tests being conducted at Cudo Technologies, Ltd. in Lexington, Kentucky are a part of The GDP Coolant Replacement Project. The tests are to be done with two alternates, C{sub 4}F{sub 10} and C{sub 4}F{sub 8}, as well as CFC-114. So far, tests were conducted with CFC-114 and C{sub 4}F{sub 10}. The CFC-114 data by Cudo shows better heat transfer performance than that predicted by the codes used in the numerical model which were based on a superposition model. The data was applied to an asymptotic model developed by Steiner and Taborek. The new correlation developed seems to fit better with the Cudo data as well as the Paducah cell test data. The model will be further investigated when C{sub 4}F{sub 8} data is available.

  14. Segmented heat exchanger

    DOE Patents [OSTI]

    Baldwin, Darryl Dean (Lafayette, IN); Willi, Martin Leo (Dunlap, IL); Fiveland, Scott Byron (Metamara, IL); Timmons, Kristine Ann (Chillicothe, IL)

    2010-12-14T23:59:59.000Z

    A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

  15. A Low-Cost, High-Efficiency Periodic Flow Gas Turbine for Distributed Energy Generation

    SciTech Connect (OSTI)

    Dr. Adam London

    2008-06-20T23:59:59.000Z

    The proposed effort served as a feasibility study for an innovative, low-cost periodic flow gas turbine capable of realizing efficiencies in the 39-48% range.

  16. Heat Transfer Characteristics of Sulfur and Sulfur Diluted with Hydrogen Sulfide Flowing Through Circular Tubes

    E-Print Network [OSTI]

    Stone, Porter Walwyn

    1960-01-01T23:59:59.000Z

    concentrations of hydrogen sulfide, using water as a basis of comparison. For identical tube sizes and the same fluid velocity, both pure and dilute sulfur were found to have a film conductance ~- I less than ten percent that of water over most... the v x d curves for each concentration of diluent. Sulfur is diluted with H2S, added as persulfide Sulfur is diluted with H S, added as liquid 34 35 10. A Ratio of film conductance of pure sulfur to that of water versus temperature. The flow...

  17. An analysis of the flow of heat from tubes buried in a concrete slab

    E-Print Network [OSTI]

    Holdredge, Ernest C

    1951-01-01T23:59:59.000Z

    T &vhoro dg i. tho amount oi' heat Ilovving in tho ti?e d&v& t!&rou, ", h on area A; n! . &;iotance vlL& owin!. to a to!r&&or?t&no dii'Torence d ~ t. !o . &star:. . I:. a~ing a thor&x~1 conductivity K. . & ncc i'cr con &?ct&& n in tho steady state, t... 12 2 ~ 000 10 1, 5 6, 0 4600 1. 19 4400 1o19 32 3 ~ OPO 1Q 1, 5 4 ~ 0 4200 lo307 3950 lo326 12 4 500 10 lo5 2 67 3300 lo442 3500 1 490 2I 0 TEST III 9 1. 0 36. 0 6450 O. 700 6900 0. 702 0, 312 9 1. 0 20. 0 6250 0, 723 6750 0, 710 o. 437 9 1. 0...

  18. Air Flow Distribution in the Sales Area of a Supermarket

    E-Print Network [OSTI]

    Fang, X.; Song, C.; Zhao, J.; Wang, Z.

    2006-01-01T23:59:59.000Z

    Many kinds of goods are displayed in a supermarket, which have their own particularities. The consumer flow rate is great and the type of shelved goods varies significantly, thereby influencing the objects that generate heat, and the demands of air...

  19. System and method for generating current by selective minority species heating

    DOE Patents [OSTI]

    Fisch, Nathaniel J. (Princeton, NJ)

    1983-01-01T23:59:59.000Z

    A system for the generation of toroidal current in a plasma which is prepared in a toroidal magnetic field. The system utilizes the injection of low-frequency waves into the plasma by means of phased antenna arrays or phased waveguide arrays. The plasma is prepared with a minority ion species of different charge state and different gyrofrequency from the majority ion species. The wave frequency and wave phasing are chosen such that the wave energy is absorbed preferentially by minority species ions traveling in one toroidal direction. The absorption of energy in this manner produces a toroidal electric current even when the injected waves themselves do not have substantial toroidal momentum. This current can be continuously maintained at modest cost in power and may be used to confine the plasma. The system can operate efficiently on fusion grade tokamak plasmas.

  20. USERíS GUIDE of TOUGH2-EGS: A Coupled Geomechanical and Reactive Geochemical Simulator for Fluid and Heat Flow in Enhanced Geothermal Systems Version 1.0

    SciTech Connect (OSTI)

    Fakcharoenphol, Perapon [Colorado School of Mines; Xiong, Yi [Colorado School of Mines; Hu, Litang; Winterfeld, Philip H. [Colorado School of Mines; Xu, Tianfu [Lawrence Berkeley National Laboratory; Wu, Yu-Shu [Colorado School of Mines

    2013-05-01T23:59:59.000Z

    TOUGH2-EGS is a numerical simulation program coupling geomechanics and chemical reactions for fluid and heat flows in porous media and fractured reservoirs of enhanced geothermal systems. The simulator includes the fully-coupled geomechanical (THM) module, the fully-coupled geochemical (THC) module, and the sequentially coupled reactive geochemistry (THMC) module. The fully-coupled flow-geomechanics model is developed from the linear elastic theory for the thermo-poro-elastic system and is formulated with the mean normal stress as well as pore pressure and temperature. The chemical reaction is sequentially coupled after solution of flow equations, which provides the flow velocity and phase saturation for the solute transport calculation at each time step. In addition, reservoir rock properties, such as porosity and permeability, are subjected to change due to rock deformation and chemical reactions. The relationships between rock properties and geomechanical and chemical effects from poro-elasticity theories and empirical correlations are incorporated into the simulator. This report provides the user with detailed information on both mathematical models and instructions for using TOUGH2-EGS for THM, THC or THMC simulations. The mathematical models include the fluid and heat flow equations, geomechanical equation, reactive geochemistry equations, and discretization methods. Although TOUGH2-EGS has the capability for simulating fluid and heat flows coupled with both geomechanical and chemical effects, it is up to the users to select the specific coupling process, such as THM, THC, or THMC in a simulation. There are several example problems illustrating the applications of this program. These example problems are described in details and their input data are presented. The results demonstrate that this program can be used for field-scale geothermal reservoir simulation with fluid and heat flow, geomechanical effect, and chemical reaction in porous and fractured media.

  1. The effect of velocity boundary conditions on the heat transfer and flow topology in two-dimensional Rayleigh-B\\'enard convection

    E-Print Network [OSTI]

    van der Poel, Erwin P; Verzicco, Roberto; Lohse, Detlef

    2015-01-01T23:59:59.000Z

    The effect of various velocity boundary condition is studied in two-dimensional Rayleigh-B\\'enard convection. Combinations of no-slip, stress-free and periodic boundary conditions are used on both the sidewalls and the horizontal plates. For the studied Rayleigh numbers Ra between $10^8$ and $10^{11}$ the heat transport is lower for $\\Gamma = 0.33$ than for $\\Gamma = 1$ in case of no-slip sidewalls. This is surprisingly opposite for stress-free sidewalls, where the heat transport increases for lower aspect-ratio. In wider cells the aspect-ratio dependence is observed to disappear for $\\text{Ra} \\ge 10^{10}$. Two distinct flow types with very different dynamics can be seen, mostly dependent on the plate velocity boundary condition, namely roll-like flow and horizontal zonal flow, which have a substantial effect on the dynamics and heat transport in the system. The predominantly horizontal zonal flow suppresses heat flux and is observed for stress-free and asymmetric plates. Low aspect-ratio periodic sidewall s...

  2. TOUGH2: A general-purpose numerical simulator for multiphase fluid and heat flow

    SciTech Connect (OSTI)

    Pruess, K.

    1991-05-01T23:59:59.000Z

    TOUGH2 is a numerical simulation program for nonisothermal flows of multicomponent, multiphase fluids in porous and fractured media. The chief applications for which TOUGH2 is designed are in geothermal reservoir engineering, nuclear waste disposal, and unsaturated zone hydrology. A successor to the TOUGH program, TOUGH2 offers added capabilities and user features, including the flexibility to handle different fluid mixtures, facilities for processing of geometric data (computational grids), and an internal version control system to ensure referenceability of code applications. This report includes a detailed description of governing equations, program architecture, and user features. Enhancements in data inputs relative to TOUGH are described, and a number of sample problems are given to illustrate code applications. 46 refs., 29 figs., 12 tabs.

  3. Local wall heat flux/temperature meter for convective flow and method of utilizing same

    DOE Patents [OSTI]

    Boyd, Ronald D.; Ekhlassi, Ali; Cofie, Penrose

    2004-11-30T23:59:59.000Z

    According to one embodiment of the invention, a method includes providing a conduit having a fluid flowing therethrough, disposing a plurality of temperature measurement devices inside a wall of the conduit, positioning at least some of the temperature measurement devices proximate an inside surface of the wall of the conduit, positioning at least some of the temperature measurement devices at different radial positions at the same circumferential location within the wall, measuring a plurality of temperatures of the wall with respective ones of the temperature measurement devices to obtain a three-dimensional temperature topology of the wall, determining the temperature dependent thermal conductivity of the conduit, and determining a multi-dimensional thermal characteristic of the inside surface of the wall of the conduit based on extrapolation of the three-dimensional temperature topology and the temperature dependent thermal conductivities.

  4. Large eddy simulation of atmospheric boundary layer flow in urban terrain : implications for transport of pollution and heat

    E-Print Network [OSTI]

    Sun, Long

    2011-01-01T23:59:59.000Z

    When the convection heat transfer model is well validated,models, convection heat transfer model is often over-and a convection heat transfer model with local accuracy is

  5. Calculation of heat flow and temperature fields for building envelopes containing thermal bridges

    SciTech Connect (OSTI)

    Childs, K.W.

    1988-01-01T23:59:59.000Z

    In a preliminary meeting held at the Princeton University Center for Energy and Environmental Studies on March 14-15, 1988, Soviet and American representatives discussed these problems in some detail. After minor modifications, final problem definitions for six of the thermal bridges were generated. The seventh thermal bridge, originally submitted by the USSR, was withdrawn temporarily to add some further clarification. A common format for presenting the results was agreed upon, and both American and Soviet specialists subsequently solved the six problems. This paper presents the US solutions prepared at ORNL. 52 figs., 6 tabs.

  6. ECI International Conference on Heat Transfer and Fluid Flow in Microscale Whistler, 21-26 September 2008

    E-Print Network [OSTI]

    Kasagi, Nobuhide

    circulation is dominant at high PeT number. A heat transfer model is proposed to analyze and predict the heat

  7. Two-dimensional model of the air flow and temperature distribution in a cavity-type heat receiver of a solar stirling engine

    SciTech Connect (OSTI)

    Makhkamov, K.K.; Ingham, D.B.

    1999-11-01T23:59:59.000Z

    A theoretical study on the air flow and temperature in the heat receiver, affected by free convection, of a Stirling Engine for a Dish/Stirling Engine Power System is presented. The standard {kappa}-{epsilon} turbulence model for the fluid flow has been used and the boundary conditions employed were obtained using a second level mathematical model of the Stirling Engine working cycle. Physical models for the distribution of the solar insolation from the Concentrator on the bottom and side walls of the cavity-type heat receiver have been taken into account. The numerical results show that most of the heat losses in the receiver are due to re-radiation from the cavity and conduction through the walls of the cavity. It is in the region of the boundary of the input window of the heat receiver where there is a sensible reduction in the temperature in the shell of the heat exchangers and this is due to the free convection of the air. Further, the numerical results show that convective heat losses increase with decreasing tilt angle.

  8. Two-phase flow interfacial drag for once through steam generators

    E-Print Network [OSTI]

    Rais, Omar Tahar

    1990-01-01T23:59:59.000Z

    to be the best available for rod bundle geometries ' ": * Bestion drift flux model'4 * Electrical Power Research Institute (EPRI) drift flux model is 29 The definitions used in the EPRI correlation involve more complex functions of flow properties.... The EPRI correlation has been validated over a much wider range of conditions than the Bestion correlation principally because its drift flux parameters depend on more flow variables9, and therefore was adopted for the purpose of this project. Overall...

  9. Predictions of flow and heat transfer in sharp 180-deg turns of gas turbine coolant channels with and without turning vanes

    SciTech Connect (OSTI)

    Bonhoff, B.; Leusch, J.; Johnson, B.V.

    1999-07-01T23:59:59.000Z

    A numerical study was conducted to determine the effects of turning vanes on the flow characteristics, the pressure drop and the heat transfer distribution in the turn region of two-legged, coolant passages for application to cooling gas turbine blades. The channels consisted of two straight, square-sectioned legs connected by a 180-deg. turn, with an inner radius of 0.15 hydraulic diameters. The ribs were square-sectioned with a height of 0.1 D{sub h}, staggered between leading and trailing side and at an angle of 45-deg. to the flow. Three different configurations of the coolant channel were investigated: with smooth walls, with ribs on two walls and no vane and with ribs on two walls and a 180-deg guide vane in the turn. For all calculations, the Reynolds number at the inlet was Re{sub D} = 100,000, the fluid was water and buoyancy effects were neglected. The simulations were made for rotation numbers, Ro = 0.0 and 0.15. The flow and heat transfer simulations were made with the FLUENT structured code. Based on the results of several previous studies, the differential-Reynolds-Stress turbulence model with wall functions was used. The highest heat transfer in the turn was obtained for both the rotating and non-rotating cases with the ribbed channel without the guide vane. The pressure loss was also higher without the vane. Due to the staggering of the ribs, secondary flow and heat transfer in the turn was higher on the side of the channel where the last rib at the entrance reaches further into the turn. With increasing rotation number, the secondary flow and heat transfer increased on the leading side of the turn. For the configuration with a 180-deg. vane, the mass flux at the outer side of the vane increased with increasing rotation number.

  10. Corrosion-induced gas generation in a nuclear waste repository: Reactive geochemistry and multiphase flow effect

    E-Print Network [OSTI]

    Xu, T.

    2009-01-01T23:59:59.000Z

    Lying Repositories for Nuclear Waste, NAGRA Technical Reporthost rock formation for nuclear waste storage. EngineeringGas Generation in a Nuclear Waste Repository: Reactive

  11. Heat pump system

    DOE Patents [OSTI]

    Swenson, Paul F. (Cleveland, OH); Moore, Paul B. (Fedhaurn, FL)

    1982-01-01T23:59:59.000Z

    An air heating and cooling system for a building includes an expansion-type refrigeration circuit and a heat engine. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The heat engine includes a heat rejection circuit having a source of rejected heat and a primary heat exchanger connected to the source of rejected heat. The heat rejection circuit also includes an evaporator in heat exchange relation with the primary heat exchanger, a heat engine indoor heat exchanger, and a heat engine outdoor heat exchanger. The indoor heat exchangers are disposed in series air flow relationship, with the heat engine indoor heat exchanger being disposed downstream from the refrigeration circuit indoor heat exchanger. The outdoor heat exchangers are also disposed in series air flow relationship, with the heat engine outdoor heat exchanger disposed downstream from the refrigeration circuit outdoor heat exchanger. A common fluid is used in both of the indoor heat exchanges and in both of the outdoor heat exchangers. In a first embodiment, the heat engine is a Rankine cycle engine. In a second embodiment, the heat engine is a non-Rankine cycle engine.

  12. Results of temperature gradient and heat flow in Santiam Pass Area, Oregon, Volume 1

    SciTech Connect (OSTI)

    Cox, B.L.; Gardner, M.C.; Koenig, J.B.

    1981-08-01T23:59:59.000Z

    The conclusions of this report are: (1) There is a weakly defined thermal anomaly within the area examined by temperature-gradient holes in the Santiam Pass area. This is a relict anomaly showing differences in permeability between the High Cascades and Western Cascades areas, more than a fundamental difference in shallow crustal temperatures. (2) The anomaly as defined by the 60 F isotherms at 400 feet follows a north-south trend immediately westward of the Cascade axis in the boundary region. It is clear that all holes spudded into High Cascades rocks result in isothermal and reversal gradients. Holes spudded in Western Cascades rocks result in positive gradients. (3) Cold groundwater flow influences and masks temperature gradients in the High Cascades to a depth of at least 700 feet, especially eastward from the major north-south trending faults. Pleistocene and Holocene rocks are very permeable aquifers. (4) Shallow gradient drilling in the lowlands westward of the faults provides more interpretable information than shallow drilling in the cold-water recharge zones. Topographic and climatological effects can be filtered out of the temperature gradient results. (5) The thermal anomaly seems to have 2 centers: one in the Belknap-Foley area, and one northward in the Sand Mountain area. The anomalies may or may not be connected along a north-south trend. (6) A geothermal effect is seen in holes downslope of the Western-High Cascade boundary. Mixing with cold waters is a powerful influence on temperature gradient data. (7) The temperature-gradient program has not yet examined and defined the geothermal resources potential of the area eastward of the Western Cascades-High Cascades boundary. Holes to 1500-2000 feet in depth are required to penetrate the high permeability-cold groundwater regime. (8) Drilling conditions are unfavorable. There are very few accessible level drill sites. Seasonal access problems and environmental restrictions together with frequent lost circulation results in very high costs per foot drilled.

  13. Visual Simulation of Heat Shimmering and Mirage

    E-Print Network [OSTI]

    Mueller, Klaus

    and the surrounding air. We introduce a heat transfer model between the heat source objects and the ambient flow the heat sources to the ambient flow. Although heat transfer modeling has been used before in computer

  14. A new correlation of the convective heat transfer coefficient between an air flow and a phase change material plate

    E-Print Network [OSTI]

    of phase change material (PCM). This correlation was built for the simulation of heat storage units: Convective heat transfer coefficient, correlation, phase change material, heat storage system, transient is the use of phase change materials (PCM). The latent heat which is needed for the material melting

  15. OPTIMIZATION AND DESIGN GUIDELINES FOR HIGH FLUX MICRO-CHANNEL HEAT SINKS FOR LIQUID AND GASEOUS SINGLE-PHASE FLOW

    E-Print Network [OSTI]

    M√ľller, Norbert

    forced convection micro-channel heat sinks for minimum pump power at high heat fluxes. Results gained orders of magnitude, especially for high heat flux devices. Using water and air as coolants, designs for heat fluxes of >10 kW/cm2 and >100 W/cm2 respectively with pump/fan power expenses less than 1

  16. Liquid Salts as Media for Process Heat Transfer from VHTR's: Forced Convective Channel Flow Thermal Hydraulics, Materials, and Coating

    SciTech Connect (OSTI)

    Sridharan, Kumar; Anderson, Mark; Allen, Todd; Corradini, Michael

    2012-01-30T23:59:59.000Z

    The goal of this NERI project was to perform research on high temperature fluoride and chloride molten salts towards the long-term goal of using these salts for transferring process heat from high temperature nuclear reactor to operation of hydrogen production and chemical plants. Specifically, the research focuses on corrosion of materials in molten salts, which continues to be one of the most significant challenges in molten salts systems. Based on the earlier work performed at ORNL on salt properties for heat transfer applications, a eutectic fluoride salt FLiNaK (46.5% LiF-11.5%NaF-42.0%KF, mol.%) and a eutectic chloride salt (32%MgCl2-68%KCl, mole %) were selected for this study. Several high temperature candidate Fe-Ni-Cr and Ni-Cr alloys: Hastelloy-N, Hastelloy-X, Haynes-230, Inconel-617, and Incoloy-800H, were exposed to molten FLiNaK with the goal of understanding corrosion mechanisms and ranking these alloys for their suitability for molten fluoride salt heat exchanger and thermal storage applications. The tests were performed at 850√?¬?√?¬?√?¬?√?¬?C for 500 h in sealed graphite crucibles under an argon cover gas. Corrosion was noted to occur predominantly from dealloying of Cr from the alloys, an effect that was particularly pronounced at the grain boundaries Alloy weight-loss due to molten fluoride salt exposure correlated with the initial Cr-content of the alloys, and was consistent with the Cr-content measured in the salts after corrosion tests. The alloys√?¬?√?¬Ę√?¬?√?¬?√?¬?√?¬? weight-loss was also found to correlate to the concentration of carbon present for the nominally 20% Cr containing alloys, due to the formation of chromium carbide phases at the grain boundaries. Experiments involving molten salt exposures of Incoloy-800H in Incoloy-800H crucibles under an argon cover gas showed a significantly lower corrosion for this alloy than when tested in a graphite crucible. Graphite significantly accelerated alloy corrosion due to the reduction of Cr from solution by graphite and formation on Cr-carbide on the graphite surface. Ni-electroplating dramatically reduced corrosion of alloys, although some diffusion of Fe and Cr were observed occur through the Ni plating. A pyrolytic carbon and SiC (PyC/SiC) CVD coating was also investigated and found to be effective in mitigating corrosion. The KCl-MgCl2 molten salt was less corrosive than FLiNaK fluoride salts for corrosion tests performed at 850oC. Cr dissolution in the molten chloride salt was still observed and consequently Ni-201 and Hastelloy N exhibited the least depth of attack. Grain-boundary engineering (GBE) of Incoloy 800H improved the corrosion resistance (as measured by weight loss and maximum depth of attack) by nearly 50% as compared to the as-received Incoloy 800H sample. Because Cr dissolution is an important mechanism of corrosion, molten salt electrochemistry experiments were initiated. These experiments were performed using anodic stripping voltammetry (ASV). Using this technique, the reduction potential of Cr was determined against a Pt quasi-reference electrode as well as against a Ni(II)-Ni reference electrode in molten FLiNaK at 650 oC. The integrated current increased linearly with Cr-content in the salt, providing for a direct assessment of the Cr concentration in a given salt of unknown Cr concentration. To study heat transfer mechanisms in these molten salts over the forced and mixed convection regimes, a forced convective loop was constructed to measure heat transfer coefficients, friction factors and corrosion rates in different diameter tubes in a vertical up flow configuration in the laminar flow regime. Equipment and instrumentation for the forced convective loop was designed, constructed, and tested. These include a high temperature centrifugal pump, mass flow meter, and differential pressure sensing capabilities to an uncertainty of < 2 Pa. The heat transfer coefficient for the KCl-MgCl2 salt was measured in t

  17. Economic Analysis and Optimization of Exterior Insulation Requirements for Ventilated Buildings at Power Generation Facilities with High Internal Heat Gain

    E-Print Network [OSTI]

    Hughes, Douglas E.

    2010-12-17T23:59:59.000Z

    Industrial buildings require a large amount of heating and ventilation equipment to maintain the indoor environment within acceptable levels for personnel protection and equipment protection. The required heating and ventilation equipment...

  18. Analysis of reactor material experiments investigating oxide fuel crust stability and heat transfer in jet impingement flow

    SciTech Connect (OSTI)

    Sienicki, J.J.; Spencer, B.W.

    1985-01-01T23:59:59.000Z

    An analysis is presented of the crust stability and heat transfer behavior in the CSTI-1, CSTI-3, and CWTI-11 reactor material experiments in which a jet of molten oxide fuel at approx. 160/sup 0/K above its freezing temperature was impinged normally upon stainless steel plates initially at 300 and 385 K. The major issue is the existence of nonexistence of a stable solidified layer of fuel, or crust, interstitial to the flowing hot fuel and the steel substrate, tending to insulate the steel from the hot molten fuel. A computer model was developed to predict the heatup of thermocouples imbedded immediately beneath the surface of the plate for both of the cases in which a stable crust is assumed to be either present or absent during the impingement phase. Comparison of the model calculations with the measured thermocouple temperatures indicates that a protective crust was present over nearly all of the plate surface area throughout the impingement process precluding major melting of the plate steel. However, the experiments also show evidence for very localized and isolated steel melting as revealed by localized and isolated pitting of the steel surface and the response of thermocouples located within the pitted region.

  19. Formulation and sequential numerical algorithms of coupled fluid/heat flow and geomechanics for multiple porosity materials

    E-Print Network [OSTI]

    Kim, J.

    2014-01-01T23:59:59.000Z

    Settari A. Modeling of geomechanics in naturally fracturedway coupled fluid flow and geomechanics in hydrate deposits.for coupled flow and geomechanics: Drained and undrained

  20. Abstract--The deployment of small (< 1-2 MW) clusters of generators, heat and electrical storage, efficiency investments,

    E-Print Network [OSTI]

    Guillas, Serge

    in electricity demand in the developed countries centers on the residential and commercial sectors in which CHP, efficiency investments, and combined heat and power (CHP) applications (particularly involving heat activated, and environmental benefits (including possible emissions credits) of combined heat and power (CHP), plus 2

  1. Three-dimensional hybrid grid generator and unstructured flow solver for compressors and turbines†

    E-Print Network [OSTI]

    Kim, Kyusup

    2005-02-17T23:59:59.000Z

    A numerical method for the simulation of compressible turbulent ?ows is presented. This method includes a novel hybrid grid generation for airfoil cascades and an unstructured mesh ?ow solver. The mesh tool ...

  2. Computational mass transfer moduling of flow through a photocatalytic oxygen generator

    E-Print Network [OSTI]

    KŲksal, Erin (Erin Sevim)

    2008-01-01T23:59:59.000Z

    A self-contained, portable oxygen generator would be extraordinarily useful across a broad spectrum of industries. Both safety and energy-efficiency could be enhanced tremendously in fields such as coal mining, commercial ...

  3. Local entropy generation analysis

    SciTech Connect (OSTI)

    Drost, M.K.; White, M.D.

    1991-02-01T23:59:59.000Z

    Second law analysis techniques have been widely used to evaluate the sources of irreversibility in components and systems of components but the evaluation of local sources of irreversibility in thermal processes has received little attention. While analytical procedures for evaluating local entropy generation have been developed, applications have been limited to fluid flows with analytical solutions for the velocity and temperature fields. The analysis of local entropy generation can be used to evaluate more complicated flows by including entropy generation calculations in a computational fluid dynamics (CFD) code. The research documented in this report consists of incorporating local entropy generation calculations in an existing CFD code and then using the code to evaluate the distribution of thermodynamic losses in two applications: an impinging jet and a magnetic heat pump. 22 refs., 13 figs., 9 tabs.

  4. Magnetic field distribution in the plasma flow generated by a plasma focus discharge

    SciTech Connect (OSTI)

    Mitrofanov, K. N., E-mail: mitrofan@triniti.ru [Troitsk Institute for Innovaiton and Fusion Research (Russian Federation); Krauz, V. I., E-mail: krauz_vi@nrcki.ru; Myalton, V. V.; Velikhov, E. P.; Vinogradov, V. P.; Vinogradova, Yu. V. [National Research Centre Kurchatov Institute (Russian Federation)

    2014-11-15T23:59:59.000Z

    The magnetic field in the plasma jet propagating from the plasma pinch region along the axis of the chamber in a megajoule PF-3 plasma focus facility is studied. The dynamics of plasma with a trapped magnetic flow is analyzed. The spatial sizes of the plasma jet region in which the magnetic field concentrates are determined in the radial and axial directions. The magnetic field configuration in the plasma jet is investigated: the radial distribution of the azimuthal component of the magnetic field inside the jet is determined. It is shown that the magnetic induction vector at a given point in space can change its direction during the plasma flight. Conclusions regarding the symmetry of the plasma flow propagation relative to the chamber axis are drawn.

  5. One- and two-dimensional Stirling machine simulation using experimentally generated reversing flow turbuulence models

    SciTech Connect (OSTI)

    Goldberg, L.F. [Univ. of Minnesota, Minneapolis, MN (United States)

    1990-08-01T23:59:59.000Z

    The activities described in this report do not constitute a continuum but rather a series of linked smaller investigations in the general area of one- and two-dimensional Stirling machine simulation. The initial impetus for these investigations was the development and construction of the Mechanical Engineering Test Rig (METR) under a grant awarded by NASA to Dr. Terry Simon at the Department of Mechanical Engineering, University of Minnesota. The purpose of the METR is to provide experimental data on oscillating turbulent flows in Stirling machine working fluid flow path components (heater, cooler, regenerator, etc.) with particular emphasis on laminar/turbulent flow transitions. Hence, the initial goals for the grant awarded by NASA were, broadly, to provide computer simulation backup for the design of the METR and to analyze the results produced. This was envisaged in two phases: First, to apply an existing one-dimensional Stirling machine simulation code to the METR and second, to adapt a two-dimensional fluid mechanics code which had been developed for simulating high Rayleigh number buoyant cavity flows to the METR. The key aspect of this latter component was the development of an appropriate turbulence model suitable for generalized application to Stirling simulation. A final-step was then to apply the two-dimensional code to an existing Stirling machine for which adequate experimental data exist. The work described herein was carried out over a period of three years on a part-time basis. Forty percent of the first year`s funding was provided as a match to the NASA funds by the Underground Space Center, University of Minnesota, which also made its computing facilities available to the project at no charge.

  6. Parametric analysis of radiative-convective heat transfer around a circular cylinder in a cross flow using the finite volume radiation solution method

    SciTech Connect (OSTI)

    Lee, K.H.; Lee, J.S.; Choi, M. [Seoul National Univ. (Korea, Republic of). Dept. of Mechanical Engineering

    1996-02-09T23:59:59.000Z

    In the outside vapor deposition (OVD) process, silica particles are deposited by thermophoretic force on the surface of a cylinder. This process is associated with complex physical phenomena such as heat transfer between a torch and a cylinder, chemical reaction for silica particle formation, and particle deposition. Since the OVD process is carried out in a very high temperature environment, radiative heat transfer should be taken into consideration. Here, the radiative-convective heat transfer around a circular cylinder in a cross flow of a radiating gas has been numerically analyzed using the finite volume radiation solution method in a nonorthogonal coordinate system. The cross-flow Reynolds number based on the cylinder diameter is 40, and the fluid Prandtl number is assumed to be 0.7. The radiative heat transfer coupled with convection is reasonably predicted by the finite volume radiation solution method. Distributions of the local Nusselt number are investigated according to the variation of radiation parameters such as conduction-to-radiation parameter, optical thickness, scattering albedo, and cylinder wall emissivity.

  7. DEVELOPMENT OF A MULTI-LOOP FLOW AND HEAT TRANSFER FACILITY FOR ADVANCED NUCLEAR REACTOR THERMAL HYDRAULIC AND HYBRID ENERGY SYSTEM STUDIES

    SciTech Connect (OSTI)

    James E. O'Brien; Piyush Sabharwall; SuJong Yoon

    2001-09-01T23:59:59.000Z

    A new high-temperature multi-fluid, multi-loop test facility for advanced nuclear applications is under development at the Idaho National Laboratory. The facility will include three flow loops: high-temperature helium, molten salt, and steam/water. Molten salts have been identified as excellent candidate heat transport fluids for primary or secondary coolant loops, supporting advanced high temperature and small modular reactors (SMRs). Details of some of the design aspects and challenges of this facility, which is currently in the conceptual design phase, are discussed. A preliminary design configuration will be presented, with the required characteristics of the various components. The loop will utilize advanced high-temperature compact printed-circuit heat exchangers (PCHEs) operating at prototypic intermediate heat exchanger (IHX) conditions. The initial configuration will include a high-temperature (750įC), high-pressure (7 MPa) helium loop thermally integrated with a molten fluoride salt (KF-ZrF4) flow loop operating at low pressure (0.2 MPa) at a temperature of ~450įC. Experiment design challenges include identification of suitable materials and components that will withstand the required loop operating conditions. Corrosion and high temperature creep behavior are major considerations. The facility will include a thermal energy storage capability designed to support scaled process heat delivery for a variety of hybrid energy systems and grid stabilization strategies. Experimental results obtained from this research will also provide important data for code ve

  8. Design of chemical reactors of the heat exchanger type

    E-Print Network [OSTI]

    McBeth, Lloyd Theodore

    1956-01-01T23:59:59.000Z

    , of the coolant varies with respect to its position in the tubes. A heat balance on the reactants is shown below. Heat balance on the reacting mass during time ae Heat in by generation = rV QR& 9 R R Heat transferred from p i = the tubes to the mass: na... at constant temper- ature, less and less heat must be removed as the reaction proceeds. This is accomplished by the gradual reduction of the coolant flow rate. A mefhod for the determination of the inanner in which the coolant rate must be varied...

  9. Automatic Test Generation for Data-Flow Reactive Systems with time constraints

    E-Print Network [OSTI]

    Boyer, Edmond

    instantaneously. We present a conformance relation for this model and we propose a test generation method using(V ) the set of variable assignments for V . Given G G(V ) and a valuation v Dom(V ), we write v |= G when G(v) true. Given a valuation v = (v1, ∑ ∑ ∑ , vn) of V and A A(V ), we define the valuations v[A] as v

  10. A statistical method for estimating wood thermal diffusivity and probe geometry using in situ heat response curves from sap flow measurements

    SciTech Connect (OSTI)

    Chen, Xingyuan; Miller, Gretchen R.; Rubin, Yoram; Baldocchi, Dennis

    2012-09-13T23:59:59.000Z

    The heat pulse method is widely used to measure water flux through plants; it works by inferring the velocity of water through a porous medium from the speed at which a heat pulse is propagated through the system. No systematic, non-destructive calibration procedure exists to determine the site-specific parameters necessary for calculating sap velocity, e.g., wood thermal diffusivity and probe spacing. Such parameter calibration is crucial to obtain the correct transpiration flux density from the sap flow measurements at the plant scale; and consequently, to up-scale tree-level water fluxes to canopy and landscape scales. The purpose of this study is to present a statistical framework for estimating the wood thermal diffusivity and probe spacing simutaneously from in-situ heat response curves collected by the implanted probes of a heat ratio apparatus. Conditioned on the time traces of wood temperature following a heat pulse, the parameters are inferred using a Bayesian inversion technique, based on the Markov chain Monte Carlo sampling method. The primary advantage of the proposed methodology is that it does not require known probe spacing or any further intrusive sampling of sapwood. The Bayesian framework also enables direct quantification of uncertainty in estimated sap flow velocity. Experiments using synthetic data show that repeated tests using the same apparatus are essential to obtain reliable and accurate solutions. When applied to field conditions, these tests are conducted during different seasons and automated using the existing data logging system. The seasonality of wood thermal diffusivity is obtained as a by-product of the parameter estimation process, and it is shown to be affected by both moisture content and temperature. Empirical factors are often introduced to account for the influence of non-ideal probe geometry on the estimation of heat pulse velocity, and they are estimated in this study as well. The proposed methodology can be applied for the calibration of existing heat ratio sap flow systems at other sites. It is especially useful when an alternative transpiration calibration device, such as a lysimeter, is not available.

  11. Quantum models with spectrum generated by the flows of polynomial zeros

    E-Print Network [OSTI]

    Alexander Moroz

    2014-10-27T23:59:59.000Z

    A class {\\cal R}_p of purely bosonic models is characterized having the following properties in the Bargmann Hilbert space of analytic functions: (i) wave function \\psi(\\epsilon,z)=\\sum_{n=0}^\\infty \\phi_n(\\epsilon) z^n is the {\\em generating function} for orthogonal polynomials \\phi_n(\\epsilon) of a discrete energy variable \\epsilon, (ii) any Hamiltonian \\hat{H}_b\\in {\\cal R}_p has nondegenerate purely point spectrum that corresponds to infinite discrete support of measure d\

  12. Dual source heat pump

    DOE Patents [OSTI]

    Ecker, Amir L. (Dallas, TX); Pietsch, Joseph A. (Dallas, TX)

    1982-01-01T23:59:59.000Z

    What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid provides energy for defrosting the second heat exchanger when operating in the air source mode and also provides a alternate source of heat.

  13. Fluidized bed heat treating system

    DOE Patents [OSTI]

    Ripley, Edward B; Pfennigwerth, Glenn L

    2014-05-06T23:59:59.000Z

    Systems for heat treating materials are presented. The systems typically involve a fluidized bed that contains granulated heat treating material. In some embodiments a fluid, such as an inert gas, is flowed through the granulated heat treating medium, which homogenizes the temperature of the heat treating medium. In some embodiments the fluid may be heated in a heating vessel and flowed into the process chamber where the fluid is then flowed through the granulated heat treating medium. In some embodiments the heat treating material may be liquid or granulated heat treating material and the heat treating material may be circulated through a heating vessel into a process chamber where the heat treating material contacts the material to be heat treated. Microwave energy may be used to provide the source of heat for heat treating systems.

  14. Heat Transfer in Smooth and Ribbed Rectangular Two-Pass Channels with a Developing Flow Entrance at High Rotation Numbers

    E-Print Network [OSTI]

    Huh, Michael

    2010-01-16T23:59:59.000Z

    on the first pass trailing surface of both aspect ratio channels. The leading surface in ribbed channels has shown a dramatic decrease in heat transfer with rotation in the first pass. Reductions in heat transfer by as much as 50% were observed. In the second...

  15. Multiphase Science and Technology, Vol. 13, No. 3, pp. 207-232, 2001 CRITICAL HEAT FLUX IN SUBCOOLED FLOW

    E-Print Network [OSTI]

    Kandlikar, Satish

    Multiphase Science and Technology, Vol. 13, No. 3, pp. 207-232, 2001 CRITICAL HEAT FLUX. Kandlikar Mechanical Engineering Department, Rochester Institute of Technology, Rochester, NY 14623, USA Abstract. Critical Heat Flux, or CHF, is an important condition that defines the upper limit of safe

  16. Woven heat exchanger

    DOE Patents [OSTI]

    Piscitella, R.R.

    1984-07-16T23:59:59.000Z

    This invention relates to a heat exchanger for waste heat recovery from high temperature industrial exhaust streams. In a woven ceramic heat exchanger using the basic tube-in-shell design, each heat exchanger consisting of tube sheets and tube, is woven separately. Individual heat exchangers are assembled in cross-flow configuration. Each heat exchanger is woven from high temperature ceramic fiber, the warp is continuous from tube to tube sheet providing a smooth transition and unitized construction.

  17. On the altitude of the ELF/VLF source region generated during "beat-wave" HF heating experiments

    E-Print Network [OSTI]

    by ionospheric heating, recent experiments at the High- frequency Active Auroral Research Program (HAARP experiments at the High-frequency Active Auroral Research Program (HAARP) HF transmitter in Gakona, Alaska

  18. Selection of Correlations and Look-Up Tables for Critical Heat Flux Prediction in the Generation IV "IRIS" Reactor

    E-Print Network [OSTI]

    Romano, A.

    In order to fulfill the goals set forth by the Generation IV International Forum, the current NERI funded

  19. The effect of longitudinal spacer ribs on the minimum pressure drop in a heated annulus

    SciTech Connect (OSTI)

    Johnston, B.S.; Neff, J.M.

    1990-01-01T23:59:59.000Z

    When evaluating a heated flow passage for vulnerability to static flow excursions, special note should be taken of flow restrictions which might allow premature vapor generation. In this study, measurements of steady state pressure drop were made for the downward flow of water in a vertical annulus. The outer wall was uniformly heated to allow subcooled boiling. Minima in the pressure drop characteristics were compared for test sections with and without longitudinal spacer ribs. For a given power and inlet temperature, the minimum occurred at a higher flow rate in the ribbed test section. This is attributed to vapor generation at the ribs. The work cited in this document show how a restriction in a heated channel can produce vapor which would not be observed in the absence of the restriction. In the present study, the effect of a flow restriction on the tendency to flow excursion is explored by finding demand curves for a heated annulus in subcooled boiling flow. The annulus is heated from the outside, and alternately equipped with and without longitudinal spacer ribs. These ribs separate the heated and unheated walls; in pressing against the heated wall they provide a means for premature vapor production.

  20. Heating system

    SciTech Connect (OSTI)

    Nishman, P.J.

    1983-03-08T23:59:59.000Z

    A heating system utilizing solar panels and buried ground conduits to collect and store heat which is delivered to a heatpump heat exchanger. A heat-distribution fluid continuously circulates through a ground circuit to transfer heat from the ground to the heat exchanger. The ground circuit includes a length of buried ground conduit, a pump, a check valve and the heat exchanger. A solar circuit, including a solar panel and a second pump, is connected in parallel with the check valve so that the distribution fluid transfers solar heat to the heat exchanger for utilization and to the ground conduit for storage when the second pump is energized. A thermostatically instrumented control system energizes the second pump only when the temperature differential between the solar panel inlet and outlet temperatures exceeds a predetermined value and the ground temperature is less than a predetermined value. Consequently, the distribution fluid flows through the solar panel only when the panel is capable of supplying significant heat to the remainder of the system without causing excessive drying of the ground.

  1. Process for oil shale retorting using gravity-driven solids flow and solid-solid heat exchange

    DOE Patents [OSTI]

    Lewis, Arthur E. (Los Altos, CA); Braun, Robert L. (Livermore, CA); Mallon, Richard G. (Livermore, CA); Walton, Otis R. (Livermore, CA)

    1986-01-01T23:59:59.000Z

    A cascading bed retorting process and apparatus in which cold raw crushed shale enters at the middle of a retort column into a mixer stage where it is rapidly mixed with hot recycled shale and thereby heated to pyrolysis temperature. The heated mixture then passes through a pyrolyzer stage where it resides for a sufficient time for complete pyrolysis to occur. The spent shale from the pyrolyzer is recirculated through a burner stage where the residual char is burned to heat the shale which then enters the mixer stage.

  2. Process for oil shale retorting using gravity-driven solids flow and solid-solid heat exchange

    DOE Patents [OSTI]

    Lewis, A.E.; Braun, R.L.; Mallon, R.G.; Walton, O.R.

    1983-09-21T23:59:59.000Z

    A cascading bed retorting process and apparatus are disclosed in which cold raw crushed shale enters at the middle of a retort column into a mixer stage where it is rapidly mixed with hot recycled shale and thereby heated to pyrolysis temperature. The heated mixture then passes through a pyrolyzer stage where it resides for a sufficient time for complete pyrolysis to occur. The spent shale from the pyrolyzer is recirculated through a burner stage where the residual char is burned to heat the shale which then enters the mixer stage.

  3. Three-dimensional numerical simulations of heat transfer in an annular fuel channel with periodic spacer ribs under a fully developed turbulent flow

    SciTech Connect (OSTI)

    Takase, Kazuyuki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)

    1997-05-01T23:59:59.000Z

    Thermal-hydraulic characteristics in a spacer-ribbed annular fuel channel for high-temperature gas-cooled reactors were analyzed numerically by three-dimensional computations under a fully developed turbulent flow. The two-equation {kappa}-{epsilon} turbulence model was applied in the present turbulent analysis, and the turbulence model constants for eddy viscosity and the turbulent Prandtl number were improved from the previous standard values to increase the accuracy of numerical simulations. Consequently, heat transfer coefficients and friction factors in the spacer-ribbed fuel channel were predicted with sufficient accuracy in the range of Reynolds number >3,000. It was clarified quantitatively that the main mechanism for heat transfer augmentation in the spacer-ribbed fuel channel was a combined effect of the turbulence promoter effect by the spacer rib and the velocity acceleration effect by a reduction in the channel cross section.

  4. FRACSTIM/I: A Fully Coupled Fluid Flow/Heat Transport and Geomechanical Deformation/Fracture Generation Simulator

    Broader source: Energy.gov [DOE]

    This research will develop a fully coupled, fully implicit approach for EGS stimulation and reservoir simulation. Solve all governing equations simultaneously in fully implicit way. Enable massively parallel performance and scalability. Apply state of the art nonlinear PDE solvers: Jacobian Free Newton Krylov (JFNK) method.

  5. Measurements of wall heat (mass) transfer for flow through blockages with round and square holes in a wide rectangular channel

    E-Print Network [OSTI]

    Cervantes, Joel

    2002-01-01T23:59:59.000Z

    ) transfer on the channel wall by 4.7 to 6.3 times, and increased the pressure drop along the test channel by up to almost 490 times that for fully developed turbulent flow through a smooth channel at the same mass flow rates. The blockages with round holes...

  6. GEOTHERMAL POWER GENERATION PLANT

    SciTech Connect (OSTI)

    Boyd, Tonya

    2013-12-01T23:59:59.000Z

    Oregon Institute of Technology (OIT) drilled a deep geothermal well on campus (to 5,300 feet deep) which produced 196oF resource as part of the 2008 OIT Congressionally Directed Project. OIT will construct a geothermal power plant (estimated at 1.75 MWe gross output). The plant would provide 50 to 75 percent of the electricity demand on campus. Technical support for construction and operations will be provided by OITís Geo-Heat Center. The power plant will be housed adjacent to the existing heat exchange building on the south east corner of campus near the existing geothermal production wells used for heating campus. Cooling water will be supplied from the nearby cold water wells to a cooling tower or air cooling may be used, depending upon the type of plant selected. Using the flow obtained from the deep well, not only can energy be generated from the power plant, but the ďwasteĒ water will also be used to supplement space heating on campus. A pipeline will be construction from the well to the heat exchanger building, and then a discharge line will be construction around the east and north side of campus for anticipated use of the ďwasteĒ water by facilities in an adjacent sustainable energy park. An injection well will need to be drilled to handle the flow, as the campus existing injection wells are limited in capacity.

  7. Utilizing the heat content of gas-to-liquids by-product streams for commercial power generation

    E-Print Network [OSTI]

    Adegoke, Adesola Ayodeji

    2006-10-30T23:59:59.000Z

    &PIfortheLNG,GTL,andIntegratedGTLPower- GenerationProjects?????????????????? 41 A1 OverviewofGTLProcessDesignedwithAspenPlus...???? 51 1 CHAPTERI INTRODUCTION 1.1 Background Naturalgasisaclean,versatileandthereforedesirablesourceoffuel.Astrongfactorthat defines..., usingtheheatcontentofthesteamstreamand/orthetail-gasstream. TheIntegratedGTLPower-Generationprocesswasmodeledusingacombination Aspen Plus, for the GTL process and Steam System Assessment Tool (DOE), for the power generation. The design of the integrated GTL Power-generation process...

  8. Multiple source heat pump

    DOE Patents [OSTI]

    Ecker, Amir L. (Duncanville, TX)

    1983-01-01T23:59:59.000Z

    A heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating a fluid in heat exchange relationship with a refrigerant fluid, at least three refrigerant heat exchangers, one for effecting heat exchange with the fluid, a second for effecting heat exchange with a heat exchange fluid, and a third for effecting heat exchange with ambient air; a compressor for compressing the refrigerant; at least one throttling valve connected at the inlet side of a heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circuit and pump for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and directional flow of refrigerant therethrough for selecting a particular mode of operation. Also disclosed are a variety of embodiments, modes of operation, and schematics therefor.

  9. A three-dimensional analysis of the flow and heat transfer for the modified chemical vapor deposition process including buoyancy, variable properties, and tube rotation

    SciTech Connect (OSTI)

    Lin, Y.T.; Choi, M.; Greif, R. (Univ. of California, Berkeley (USA))

    1991-05-01T23:59:59.000Z

    A study has been made of the heat transfer, flow, and particle deposition relative to the modified chemical vapor deposition (MCVD) process. The effects of variable properties, buoyancy, and tube rotation have been included in the study. The resulting three-dimensional temperature and velocity fields have been obtained for a range of conditions. The effects of buoyancy result in asymmetric temperature and axial velocity profiles with respect to the tube axis. Variable properties cause significant variations in the axial velocity along the tube and in the secondary flow in the region near the torch. Particle trajectories are shown to be strongly dependent on the tube rotation and are helices for large rotational speeds. The component of secondary flow in the radial direction is compared to the thermophoretic velocity, which is the primary cause of particle deposition in the MCVD process. Over the central portion of the tube the radial component of the secondary flow is most important in determining the motion of the particles.

  10. Numerical simulation of the fluid flow and heat transfer processes during scavenging in a two-stroke engine under steady-state conditions

    SciTech Connect (OSTI)

    Castro Gouveia, M. de; Reis Parise, J.A. dos; Nieckele, A.O. (Pontificia Univ. Catolica, Rio de Janeiro (Brazil))

    1992-05-01T23:59:59.000Z

    A numerical simulation of the scavenging process in a two-stroke flat-piston model engine has been developed. Air enters the cylinder circumferentially, inducting a three-dimensional turbulent swirling flow. The problem was modeled as a steady-state axisymmetric flow through a cylinder with uniform wall temperature. The steady-state regime was simulated by assuming the piston head fixed at the bottom dead center. The calculation was performed employing the {kappa}-{epsilon} model of turbulence. A comparison of the results obtained for the flow field with available experimental data showed very good agreement, and a comparison with an available numerical solution revealed superior results. The effects of the Reynolds number, inlet port angles, and engine geometry on the flow and in-cylinder heat transfer characteristics were investigated. The Nusselt number substantially increases with larger Reynolds numbers and a smaller bore-to-stroke ratio. It is shown that the positioning of the exhaust value(s) is the main parameter to control the scavenging process.

  11. Study of instabilities and quasi-two-dimensional turbulence in volumetrically heated magnetohydrodynamic flows in a vertical rectangular duct

    E-Print Network [OSTI]

    Abdou, Mohamed

    magnetohydrodynamic flows in a vertical rectangular duct N. Vetcha, S. Smolentsev, M. Abdou, and R. Moreau Citation in a vertical rectangular duct N. Vetcha,1 S. Smolentsev,1,a) M. Abdou,1 and R. Moreau2 1 Mechanical

  12. Development of Micro/Nano-Scale Sensors for Investigation of Heat Transfer in Multi-Phase Flows

    E-Print Network [OSTI]

    Jeon, Sae Il

    2012-10-19T23:59:59.000Z

    boiling experiments were conducted for three different substrates. Flow boiling experiments on bare silicon wafer surface were treated as the control experiment, and the results were compared with that of CNT (Carbon Nano-Tube) coated silicon wafer...

  13. Fuel Cell Power Model Version 2: Startup Guide, System Designs, and Case Studies. Modeling Electricity, Heat, and Hydrogen Generation from Fuel Cell-Based Distributed Energy Systems

    SciTech Connect (OSTI)

    Steward, D.; Penev, M.; Saur, G.; Becker, W.; Zuboy, J.

    2013-06-01T23:59:59.000Z

    This guide helps users get started with the U.S. Department of Energy/National Renewable Energy Laboratory Fuel Cell Power (FCPower) Model Version 2, which is a Microsoft Excel workbook that analyzes the technical and economic aspects of high-temperature fuel cell-based distributed energy systems with the aim of providing consistent, transparent, comparable results. This type of energy system would provide onsite-generated heat and electricity to large end users such as hospitals and office complexes. The hydrogen produced could be used for fueling vehicles or stored for later conversion to electricity.

  14. Entropy generation minimization of a heat and mass exchanger for use in a humidification-dehumidification desalination system

    E-Print Network [OSTI]

    Thiel, Gregory P

    2012-01-01T23:59:59.000Z

    The physical mechanisms of entropy generation in a condenser with high fractions of non-condensable gases are examined using control volume, scaling, and boundary layer techniques, with the aim of defining a criterion for ...

  15. Project Title: Small Scale Electrical Power Generation from Heat Co-Produced in Geothermal Fluids: Mining Operation

    SciTech Connect (OSTI)

    Clark, Thomas M [Principal Investigator; Erlach, Celeste [Communications Mgr.

    2014-12-30T23:59:59.000Z

    Demonstrate the technical and economic feasibility of small scale power generation from low temperature co-produced fluids. Phase I is to Develop, Design and Test an economically feasible low temperature ORC solution to generate power from lower temperature co-produced geothermal fluids. Phase II &III are to fabricate, test and site a fully operational demonstrator unit on a gold mine working site and operate, remotely monitor and collect data per the DOE recommended data package for one year.

  16. The microcanonical thermodynamics of finite systems: The microscopic origin of condensation and phase separations; and the conditions for heat flow from lower to higher temperatures

    E-Print Network [OSTI]

    D. H. E. Gross; J. F. Kenney

    2005-03-24T23:59:59.000Z

    Microcanonical thermodynamics allows the application of statistical mechanics both to finite and even small systems and also to the largest, self-gravitating ones. However, one must reconsider the fundamental principles of statistical mechanics especially its key quantity, entropy. Whereas in conventional thermostatistics, the homogeneity and extensivity of the system and the concavity of its entropy are central conditions, these fail for the systems considered here. For example, at phase separation, the entropy, S(E), is necessarily convex to make exp[S(E)-E/T] bimodal in E. Particularly, as inhomogeneities and surface effects cannot be scaled away, one must be careful with the standard arguments of splitting a system into two subsystems, or bringing two systems into thermal contact with energy or particle exchange. Not only the volume part of the entropy must be considered. As will be shown here, when removing constraints in regions of a negative heat capacity, the system may even relax under a flow of heat (energy) against a temperature slope. Thus the Clausius formulation of the second law: ``Heat always flows from hot to cold'', can be violated. Temperature is not a necessary or fundamental control parameter of thermostatistics. However, the second law is still satisfied and the total Boltzmann entropy increases. In the final sections of this paper, the general microscopic mechanism leading to condensation and to the convexity of the microcanonical entropy at phase separation is sketched. Also the microscopic conditions for the existence (or non-existence) of a critical end-point of the phase-separation are discussed. This is explained for the liquid-gas and the solid-liquid transition.

  17. Heat can flow from cold to hot in Microcanonical Thermodynamics of finite systems. The microscopic origin of condensation and phase separations

    E-Print Network [OSTI]

    D. H. E. Gross

    2004-09-21T23:59:59.000Z

    Microcanonical Thermodynamics allows the application of Statistical Mechanics on one hand to closed finite and even small systems and on the other to the largest,self-gravitating ones. However, one has to reconsider the fundamental principles of Statistical Mechanics especially its key quantity, entropy. Whereas in conventional Thermostatistics the homogeneity and extensivity of the system and the concavity of its entropy S(E) are central conditions, these fail for the systems considered here. E.g. at phase separation the entropy S(E) is necessarily convex to make e^{S(E)-E/T} bimodal in E (the two coexisting phases). This is so even for normal macroscopic systems with short-range coupling. As inhomogeneities and surface effects in particular cannot be scaled away,one has to be careful with the standard arguments of splitting a system into two or bringing two systems into thermal contact. Not only the volume part of the entropy must be considered. When removing an external constraint in regions of a negative heat capacity, the system may even relax under a flow of heat (energy) against the temperature slope. Thus Clausius formulation of the Second Law: "Heat always flows from hot to cold" can be violated. Temperature is not a necessary or fundamental control parameter of Thermostatistics. In the final sections of this paper the general microscopic mechanism leading to condensation and to the convexity of the microcanonical entropy S(E) at phase separation is sketched. Also the microscopic conditions for the existence or non-existence of a critical end-point of the phase-separation are discussed. This is explained for the liquid--gas and the solid--liquid transition.

  18. Chaotic flow in a 2D natural convection loop with heat flux boundaries William F. Louisos a,b,

    E-Print Network [OSTI]

    Danforth, Chris

    . Examples of natural convection cells occurring in engineering devices include solar water heaters, nu into the system while the upper half is cooled by an equal-but- opposite heat flux out of the system. Water between landmass and an adjacent body of water; mantle convection of the Earth's asthenosphere which

  19. Turbine vanes experience high convective surface heat transfer as a consequence of the turbulent flow exiting the combustor. Before im-

    E-Print Network [OSTI]

    Thole, Karen A.

    1 Abstract Turbine vanes experience high convective surface heat transfer as a consequence region of the passage reacts as it passes between two adjacent turbine vanes. In this study, a scaled-up turbine vane geometry was used in a low-speed wind tunnel simulation. The test section included a cen

  20. Transient Thermal, Hydraulic, and Mechanical Analysis of a Counter Flow Offset Strip Fin Intermediate Heat Exchanger using an Effective Porous Media Approach

    E-Print Network [OSTI]

    Urquiza, Eugenio

    2009-01-01T23:59:59.000Z

    low volumetric heat capacity (relative to liquid-cooledvolumetric heat capacity relative to the liquid salt. Thisvolumetric heat capacity (?*c p ) of the liquid salt permits

  1. Scaled Experimental Modeling of VHTR Plenum Flows

    SciTech Connect (OSTI)

    ICONE 15

    2007-04-01T23:59:59.000Z

    Abstract The Very High Temperature Reactor (VHTR) is the leading candidate for the Next Generation Nuclear Power (NGNP) Project in the U.S. which has the goal of demonstrating the production of emissions free electricity and hydrogen by 2015. Various scaled heated gas and water flow facilities were investigated for modeling VHTR upper and lower plenum flows during the decay heat portion of a pressurized conduction-cooldown scenario and for modeling thermal mixing and stratification (ďthermal stripingĒ) in the lower plenum during normal operation. It was concluded, based on phenomena scaling and instrumentation and other practical considerations, that a heated water flow scale model facility is preferable to a heated gas flow facility and to unheated facilities which use fluids with ranges of density to simulate the density effect of heating. For a heated water flow lower plenum model, both the Richardson numbers and Reynolds numbers may be approximately matched for conduction-cooldown natural circulation conditions. Thermal mixing during normal operation may be simulated but at lower, but still fully turbulent, Reynolds numbers than in the prototype. Natural circulation flows in the upper plenum may also be simulated in a separate heated water flow facility that uses the same plumbing as the lower plenum model. However, Reynolds number scaling distortions will occur at matching Richardson numbers due primarily to the necessity of using a reduced number of channels connected to the plenum than in the prototype (which has approximately 11,000 core channels connected to the upper plenum) in an otherwise geometrically scaled model. Experiments conducted in either or both facilities will meet the objectives of providing benchmark data for the validation of codes proposed for NGNP designs and safety studies, as well as providing a better understanding of the complex flow phenomena in the plenums.

  2. Prediction of turbulent flow and local heat transfer in internally cooled turbine airfoils: the leading edge region

    E-Print Network [OSTI]

    Pontaza, Juan Pablo

    2013-02-22T23:59:59.000Z

    -Stokes equations and the energy equation in conjunction with a two-layer K-Epsilon isotropic eddy viscosity model and a near-wall Reynolds-Stress closure model. The fundamental cases of fully developed turbulent pipe flow and an axisymmetric jet impinging on a...

  3. Numerical Simulation of Flow and Heat Transfer in Internal Multi-Pass Cooling Channel within Gas Turbine Blade

    E-Print Network [OSTI]

    Chu, Hung-Chieh 1979-

    2012-11-16T23:59:59.000Z

    four-pass channel with two different inlet settings. The main flowing channel was rectangular channel (AR=2:1) with hydraulic diameter (Dh ) equals to 2/3 inch (16.9 mm). The first and fourth channel were set as different aspect ratio (AR=2:1; AR=1...

  4. PIV flow measurements for heat transfer characterization in two-pass square channels with smooth and 90 ribbed walls

    E-Print Network [OSTI]

    Kihm, IconKenneth David

    -pass square channel with a smooth wall and a 90į rib-roughened wall. Detailed averaged velocity distributions enhancements for both smooth and ribbed wall two-pass square channels. The rib-induced flow turbulence distribution in two-pass square channels with smooth and 90į ribbed walls. Han and Zhang [3] studied the effect

  5. Fusion Engineering and Design 81 (2006) 549553 Numerical analysis of MHD flow and heat transfer in a

    E-Print Network [OSTI]

    Abdou, Mohamed

    2006-01-01T23:59:59.000Z

    . Zinkle, M. Youssef, Assessment of liquid breeder first wall and blanket options for the DEMO design, in channels. tural material. Helium cools the fist wall and blanket structure, and the self-cooled breeder, Pb in a poloidal channel of the DCLL blanket with a SiCf/SiC flow channel insert S. Smolentseva,, M. Abdoua, N

  6. ECI International Conference on Heat Transfer and Fluid Flow in Microscale Whistler, 21-26 September 2008

    E-Print Network [OSTI]

    Bahrami, Majid

    the properties of porous media e.g. permeability. This can be achieved by using Darcy's equation which assumes is empirical, convenient, and widely accepted. However, Darcy's equation holds when flow is in creeping regime [4]. To use Darcy's equation we need to know the permeability of the medium beforehand. Permeability

  7. Evaluation on double-wall-tube residual stress distribution of sodium-heated steam generator by neutron diffraction and numerical analysis

    SciTech Connect (OSTI)

    Kisohara, N. [Advanced Nuclear System Research and Development Directorate, Japan Atomic Energy Agency (Japan); Suzuki, H.; Akita, K. [Quantum Beam Science Directorate, Japan Atomic Energy Agency (Japan); Kasahara, N. [Dept. of Nuclear Engineering and Management, Univ. of Tokyo (Japan)

    2012-07-01T23:59:59.000Z

    A double-wall-tube is nominated for the steam generator heat transfer tube of future sodium fast reactors (SFRs) in Japan, to decrease the possibility of sodium/water reaction. The double-wall-tube consists of an inner tube and an outer tube, and they are mechanically contacted to keep the heat transfer of the interface between the inner and outer tubes by their residual stress. During long term SG operation, the contact stress at the interface gradually falls down due to stress relaxation. This phenomenon might increase the thermal resistance of the interface and degrade the tube heat transfer performance. The contact stress relaxation can be predicted by numerical analysis, and the analysis requires the data of the initial residual stress distributions in the tubes. However, unclear initial residual stress distributions prevent precious relaxation evaluation. In order to resolve this issue, a neutron diffraction method was employed to reveal the tri-axial (radius, hoop and longitudinal) initial residual stress distributions in the double-wall-tube. Strain gauges also were used to evaluate the contact stress. The measurement results were analyzed using a JAEA's structural computer code to determine the initial residual stress distributions. Based on the stress distributions, the structural computer code has predicted the transition of the relaxation and the decrease of the contact stress. The radial and longitudinal temperature distributions in the tubes were input to the structural analysis model. Since the radial thermal expansion difference between the inner (colder) and outer (hotter) tube reduces the contact stress and the tube inside steam pressure contributes to increasing it, the analytical model also took these effects into consideration. It has been conduced that the inner and outer tubes are contacted with sufficient stresses during the plant life time, and that effective heat transfer degradation dose not occur in the double-wall-tube SG. (authors)

  8. Dependency of Heat Transfer Rate on the Brinkman Number in Microchannels

    E-Print Network [OSTI]

    H. S. Park

    2008-01-07T23:59:59.000Z

    Heat generation from electronics increases with the advent of high-density integrated circuit technology. To come up with the heat generation, microscale cooling has been thought as a promising technology. Prediction of heat transfer rate is crucial in design of microscale cooling device but is not clearly understood yet. This work proposes a new correlation between heat transfer rate and Brinkman number which is nondimensional number of viscosity, flow velocity and temperature. It is expected that the equation proposed by this work can be useful to design microchannel cooling device.

  9. Progress in Grid Scale Flow Batteries

    E-Print Network [OSTI]

    2011Year #12;Flow Battery Research at PNNL and Sandia #12 with industries and universities New Generation Redox Flow Batteries, PNNL Developed new generation redox flow

  10. Generator configuration for solid oxide fuel cells

    DOE Patents [OSTI]

    Reichner, Philip (Plum Boro, PA)

    1989-01-01T23:59:59.000Z

    Disclosed are improvements in a solid oxide fuel cell generator 1 having a multiplicity of electrically connected solid oxide fuel cells 2, where a fuel gas is passed over one side of said cells and an oxygen-containing gas is passed over the other side of said cells resulting in the generation of heat and electricity. The improvements comprise arranging the cells in the configuration of a circle, a spiral, or folded rows within a cylindrical generator, and modifying the flow rate, oxygen concentration, and/or temperature of the oxygen-containing gases that flow to those cells that are at the periphery of the generator relative to those cells that are at the center of the generator. In these ways, a more uniform temperature is obtained throughout the generator.

  11. Experimental measurements in a radio frequency discharge heated supersonic flow: Evaluation of a potential electric propulsion thruster

    SciTech Connect (OSTI)

    Wantuck, P.J.; Hull, D.E.

    1991-01-01T23:59:59.000Z

    An operational radio frequency discharge-driven supersonic flow system, which utilizes an inductively and capacitively coupled plasma (ICCP) tube to produce high enthalpy source gas, is described. The ICCP coupled to a properly designed nozzle represents a potential electric propulsion device. The high gas temperatures achieved in the plasma discharge (> 5000 K) and the electrodeless nature of the tube's operation offers potentially high thruster performance coupled and long operational lifetime. A preliminary characterization of the current system was established using emission and probe-based measurements. A nominal peak specific impulse of 155 s was estimated for operation with argon. The calculated thrust based upon the peak velocity and mass flow through the device is 1.1 N. 14 refs., 10 figs.

  12. Measurements of wall heat (mass) transfer for flow through blockages with round and square holes in a wide rectangular channel†

    E-Print Network [OSTI]

    Cervantes, Joel

    2002-01-01T23:59:59.000Z

    . . . n1 DEDICATION. ACKNOWLEGDEMENTS . . . V1 TABLE OF CONTENTS . vn LIST OF FIGURES. NOMENCLATURE . . INTRODUCTION. LITERATURE SURVEY. EXPERIMENTAL APPARATUS . Xt EXPERIMENTAL PROCEDURE DATA REDUCTION. PRESENTATION & DISCUSSION OF RESULTS..., kg/(m s) Nun~ local Nusselt number //u pa average Nusselt number Nus reference Nusselt number for fully developed turbulent flow in smooth channel POIIII Pv, w atmospheric pressure, N/m 2 vapor pressure on naphthalene surface, N/m 2 P...

  13. Integrity assessment of the ferritic / austenitic dissimilar weld joint between intermediate heat exchanger and steam generator in fast reactor

    SciTech Connect (OSTI)

    Jayakumar, T.; Laha, K.; Chandravathi, K. S.; Parameswaran, P.; Goyal, S.; Kumar, J. G.; Mathew, M. D. [Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam- 603 102 (India)

    2012-07-01T23:59:59.000Z

    Integrity of the modified 9Cr-1Mo / alloy 800 dissimilar joint welded with Inconel 182 electrodes has been assessed under creep condition based on the detailed analysis of microstructure and stress distribution across the joint by finite element analysis. A hardness peak at the ferritic / austenitic weld interface and a hardness trough at the inter-critical heat affected zone (HAZ) in ferritic base metal developed. Un-tempered martensite was found at the ferritic / austenitic weld interface to impart high hardness in it; whereas annealing of martensitic structure of modified 9Cr-1Mo steel by inter-critical heating during welding thermal cycle resulted in hardness tough in the inter-critical HAZ. Creep tests were carried out on the joint and ferritic steel base metal at 823 K over a stress range of 160-320 MPa. The joint possessed lower creep rupture strength than its ferritic steel base metal. Failure of the joint at relatively lower stresses occurred at the ferritic / austenitic weld interface; whereas it occurred at inter-critical region of HAZ at moderate stresses. Cavity nucleation associated with the weld interface particles led to premature failure of the joint. Finite element analysis of stress distribution across the weld joint considering the micro-mechanical strength inhomogeneity across it revealed higher von-Mises and principal stresses at the weld interface. These stresses induced preferential creep cavitation at the weld interface. Role of precipitate in enhancing creep cavitation at the weld interface has been elucidated based on the FE analysis of stress distribution across it. (authors)

  14. Metallurgical technologies, energy conversion, and magnetohydrodynamic flows

    SciTech Connect (OSTI)

    Branover, H.; Unger, Y.

    1993-01-01T23:59:59.000Z

    The present volume discusses metallurgical applications of MHD, R D on MHD devices employing liquid working medium for process applications, electromagnetic (EM) modulation of molten metal flow, EM pump performance of superconducting MHD devices, induction EM alkali-metal pumps, a physical model for EM-driven flow in channel-induction furnaces, grain refinement in Al alloys via EM vibrational method, dendrite growth of solidifying metal in dc magnetic field, MHD for mass and heat transfer in single-crystal melt growth, inverse EM shaping, and liquid-metal MHD development in Israel. Also discussed are the embrittlement of steel by lead, an open cycle MHD disk generator, the acceleration of gas-liquid piston flows for molten-metal MHD generators, MHD flow around a cylinder, new MHD drag coefficients, liquid-metal MHD two-phase flow, and two-phase liquid gas mixers for MHD energy conversion.

  15. Growth and mortality of the oyster, Crassostrea virginica (Gmelin) in an electric generating station cooling lake receiving heated discharge water

    E-Print Network [OSTI]

    Oja, Robert Kenneth

    1974-01-01T23:59:59.000Z

    throughout the tudy. STUDY ARZA AND ?)vTHODS Studg Area Thi. study was conducted at the Houston Lighting and Power Camp- y's Cedar Bayou Generating Station in Baytown, Texas. The plant comprises two 750-mcg watt units with individual water circulating... group, was located at the . intake canal of the power plant. The remaining four stations were located within the cooling lake (I'ig. 2, p. ll ). The station oositions were selected to encompass th maximum water temperature range within the lake. Prior...

  16. Characterization and Quantification of Electronic and Ionic Ohmic Overpotential and Heat Generation in a Solid Oxide Fuel Cell Anode

    SciTech Connect (OSTI)

    Grew, Kyle N.; Izzo, John R.; Chiu, Wilson K.S.

    2011-08-16T23:59:59.000Z

    The development of a solid oxide fuel cell (SOFC) with a higher efficiency and power density requires an improved understanding and treatment of the irreversibilities. Losses due to the electronic and ionic resistances, which are also known as ohmic losses in the form of Joule heating, can hinder the SOFC's performance. Ohmic losses can result from the bulk material resistivities as well as the complexities introduced by the cell's microstructure. In this work, two-dimensional (2D), electronic and ionic transport models are used to develop a method of quantification of the ohmic losses within the SOFC anode microstructure. This quantification is completed as a function of properties determined from a detailed microstructure characterization, namely, the tortuosity of the electronic and ionic phases, phase volume fraction, contiguity, and mean free path. A direct modeling approach at the level of the pore-scale microstructure is achieved through the use of a representative volume element (RVE) method. The correlation of these ohmic losses with the quantification of the SOFC anode microstructure are examined. It is found with this analysis that the contributions of the SOFC anode microstructure on ohmic losses can be correlated with the volume fraction, contiguity, and mean free path.

  17. Characterization and Quantification of Electronic and Ionic Ohmic Overpotential and Heat Generation in a Solid Oxide Fuel Cell Anode

    SciTech Connect (OSTI)

    Grew, Kyle N.; Izzo, Jr., John R.; Chiu, W. K. S.

    2011-01-01T23:59:59.000Z

    The development of a solid oxide fuel cell (SOFC) with a higher efficiency and power density requires an improved understanding and treatment of the irreversibilities. Losses due to the electronic and ionic resistances, which are also known as ohmic losses in the form of Joule heating, can hinder the SOFCís performance. Ohmic losses can result from the bulk material resistivities as well as the complexities introduced by the cellís microstructure. In this work, two-dimensional (2D), electronic and ionic transport models are used to develop a method of quantification of the ohmic losses within the SOFC anode microstructure. This quantification is completed as a function of properties determined from a detailed microstructure characterization, namely, the tortuosity of the electronic and ionic phases, phase volume fraction, contiguity, and mean free path. A direct modeling approach at the level of the pore-scale microstructure is achieved through the use of a representative volume element (RVE) method. The correlation of these ohmic losses with the quantification of the SOFC anode microstructure are examined. It is found with this analysis that the contributions of the SOFC anode microstructure on ohmic losses can be correlated with the volume fraction, contiguity, and mean free path.

  18. Temperature distribution in an oscillatory flow with a sinusoidal wall temperature

    E-Print Network [OSTI]

    Texas at Austin. University of

    generated by an oscillatory boundary layer flow in the presence of a wall with a sinusoidal temperatureTemperature distribution in an oscillatory flow with a sinusoidal wall temperature Eduardo Ramos a that in all cases, the long-time, time averaged heat transfer from the boundary to the fluid is zero. ” 2004

  19. Thulium-170 heat source

    DOE Patents [OSTI]

    Walter, Carl E. (Pleasanton, CA); Van Konynenburg, Richard (Livermore, CA); VanSant, James H. (Tracy, CA)

    1992-01-01T23:59:59.000Z

    An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

  20. Advanced Thermoelectric Materials and Generator Technology for...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Thermoelectric Materials and Generator Technology for Automotive Waste Heat at GM Advanced Thermoelectric Materials and Generator Technology for Automotive Waste Heat at GM...