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Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Heat transfer and pressure drop in tape generated swirl flow  

E-Print Network [OSTI]

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 ...

Lopina, Robert F.

1967-01-01T23:59:59.000Z

2

Cooling Flows or Heating Flows?  

E-Print Network [OSTI]

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.

James Binney

2003-10-08T23:59:59.000Z

3

Convective heat flow probe  

DOE Patents [OSTI]

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.

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

1984-01-09T23:59:59.000Z

4

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

E-Print Network [OSTI]

/water, such as for estimating hydraulic loads on relief valve discharge lines. CHAPTER III ONCE THROUGH STEAM GENERATOR III. 1 B&W Once Through Steam Generator Description The B&W Once Through Steam Generator (OTSG), illustrated in Figure 1, is a vertical, straight ? tube... a liquid droplet developed by Taitel and Duklerr. 7 [~9(Pf ? Pg)] ' os ? w = MAX 0. 75, 1. 4 Vg pgg (18) It also places a. limit on the range of the slug ? to ? annular transition. 0. 75 & og ~ & 0. 96 (19) Two points need to be made. First...

Blanchat, Thomas Kevin

1988-01-01T23:59:59.000Z

5

Radial flow heat exchanger  

DOE Patents [OSTI]

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.

Valenzuela, Javier (Hanover, NH)

2001-01-01T23:59:59.000Z

6

Control system for fluid heated steam generator  

DOE Patents [OSTI]

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.

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

1984-05-29T23:59:59.000Z

7

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...

8

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...

9

FRACSTIM/I: A Fully Coupled Fluid Flow/Heat Transport and Geomechanica...  

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

FRACSTIMI: A Fully Coupled Fluid FlowHeat Transport and Geomechanical DeformationFracture Generation Simulator FRACSTIMI: A Fully Coupled Fluid FlowHeat Transport and...

10

Distributed Generation with Heat Recovery and Storage  

E-Print Network [OSTI]

Energy; Grid systems; Optimization; Heat flow; Financialof grid power and by utilizing combined heat and power (CHP)

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

2008-01-01T23:59:59.000Z

11

MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER  

E-Print Network [OSTI]

MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER "ENGINEERING APPLICATIONS OF FRACTAL and multiphase flow & heat transfer will be stressed. This paper will begin by reviewing some important concepts

Lahey, Richard T.

12

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,...

13

Heat Recovery Steam Generator Simulation  

E-Print Network [OSTI]

The paper discusses the applications of Heat Recovery Steam Generator Simulation. Consultants, plant engineers and plant developers can evaluate the steam side performance of HRSGs and arrive at the optimum system which matches the needs...

Ganapathy, V.

14

Distributed Generation with Heat Recovery and Storage  

E-Print Network [OSTI]

of fossil fuel sources of waste heat and other lossesthat this is only the waste heat from fossil generation,an estimate of the total waste heat from fossil generation

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

2008-01-01T23:59:59.000Z

15

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

Open Energy Info (EERE)

Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow Measurements And Heat-Flow Estimates From The Uk Geothermal Catalogue Jump to: navigation, search OpenEI Reference...

16

Distributed Generation with Heat Recovery and Storage  

E-Print Network [OSTI]

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

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

2008-01-01T23:59:59.000Z

17

Colorado Heat Flow Data from IHFC  

SciTech Connect (OSTI)

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

Zehner, Richard E.

2012-02-01T23:59:59.000Z

18

Control of flow through a vapor generator  

DOE Patents [OSTI]

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.

Radcliff, Thomas D.

2005-11-08T23:59:59.000Z

19

Distributed Generation with Heat Recovery and Storage  

E-Print Network [OSTI]

power generation with combined heat and power applications,Ēof carbon tax on combined heat and power adoption by a131(1), 2-25. US Combined Heat and Power Association (

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

2008-01-01T23:59:59.000Z

20

Solar steam generation by heat localization  

E-Print Network [OSTI]

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 ...

Ghasemi, Hadi

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Heat engine generator control system  

DOE Patents [OSTI]

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.

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

22

Heat engine generator control system  

DOE Patents [OSTI]

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.

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

1998-05-12T23:59:59.000Z

23

Heat Transfer Characteristics of a Generalized Divided Flow Heat Exchanger  

E-Print Network [OSTI]

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...

Singh, K. P.

1979-01-01T23:59:59.000Z

24

FRACSTIM/I: A Fully Coupled Fluid Flow/Heat Transport and Geomechanica...  

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

FRACSTIMI: A Fully Coupled Fluid FlowHeat Transport and Geomechanical DeformationFracture Generation Simulator aka FALCON: Fracturing and Liquid CONservation Robert K....

25

Waste Heat Recovery Power Generation with WOWGen  

E-Print Network [OSTI]

Waste Heat Recovery Power Generation with WOWGen? Business Overview WOW operates in the energy efficiency field - one of the fastest growing energy sectors in the world today. The two key products - WOWGen? and WOWClean? provide more... energy at cheaper cost and lower emissions. ? WOWGen? - Power Generation from Industrial Waste Heat ? WOWClean? - Multi Pollutant emission control system Current power generation technology uses only 35% of the energy in a fossil fuel...

Romero, M.

26

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)...

27

An evaluation of heat flow transducers as a means of determining soil heat flow  

E-Print Network [OSTI]

provided to the Micrometeorology Section, Department of Oceanography and Meteorology, ARM College of Texas by the Signal Corps of the United States Army, under Contract No. DA 36-039 AMC-02195 (E). The heat flow plates used in this study were provided... surface soil heat flow. The results show that acceptable performance of the plates in the measurement of heat flow is possible although in general should not be expected without thorough testing, and even then there are restrictive considerations...

King, Barney L. D

2012-06-07T23:59:59.000Z

28

Corner heating in rectangular solid oxide electrochemical cell generators  

DOE Patents [OSTI]

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.

Reichner, Philip (Plum Boro, PA)

1989-01-01T23:59:59.000Z

29

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]

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 volume§ . The flow volume is filled with vertical equidistant heated blades

Kihm, IconKenneth David

30

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

SciTech Connect (OSTI)

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.

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

2002-08-01T23:59:59.000Z

31

Joule heating generated by spin current through Josephson junctions  

SciTech Connect (OSTI)

We theoretically study the spin-polarized current flowing through a Josephson junction (JJ) in a spin injection device. When the spin-polarized current is injected from a ferromagnet in a superconductor (SC), the charge current is carried by the superconducting condensate (Cooper pairs), while the spin-up and spin-down currents flow in equal magnitude but in the opposite direction in a SC, because of no quasiparticle charge current in the SC. This indicates that not only the Josephson current but also the spin current flow across JJ at zero bias voltage, thereby generating Joule heating by the spin current. The result provides a new method for detecting the spin current by measuring Joule heating at JJ. {copyright} 2001 American Institute of Physics.

Takahashi, S.; Yamashita, T.; Koyama, T.; Maekawa, S.; Imamura, H.

2001-06-01T23:59:59.000Z

32

Generator powered electrically heated diesel particulate filter  

DOE Patents [OSTI]

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.

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

2014-03-18T23:59:59.000Z

33

Heat Flow Determinations and Implied Thermal Regime of the Coso...  

Open Energy Info (EERE)

group, greater than 6.5 HFU, are characteristic of regions with considerable convective heat transfer in the shallow subsurface. The high heat flow values are essentially...

34

Heat flow determinations and implied thermal regime of the Coso...  

Open Energy Info (EERE)

group, greater than 6.5 HFU, are characteristic of regions with considerable convective heat transfer in the shallow subsurface. The high heat flow values are essentially...

35

Triaxial thermopile array geo-heat-flow sensor  

DOE Patents [OSTI]

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.

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

1990-01-01T23:59:59.000Z

36

Triaxial thermopile array geo-heat-flow sensor  

DOE Patents [OSTI]

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.

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

37

Plume heat flow is much lower than CMB heat flow Eric Mittelstaedt a,*, Paul J. Tackley a,b  

E-Print Network [OSTI]

to follow a power-law size distribution, estimated a plume heat flux as high as 35% of surface heat fluxPlume heat flow is much lower than CMB heat flow Eric Mittelstaedt a,*, Paul J. Tackley a, of the heat conducted across the CMB. Here this assumption is explored using numerical convection models

Tackley, Paul J.

38

Hydrodynamics, heat transfer and flow boiling instabilities in microchannels†  

E-Print Network [OSTI]

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 ...

Barber, Jacqueline Claire

2010-01-01T23:59:59.000Z

39

Radio frequency (RF) heated supersonic flow laboratory  

SciTech Connect (OSTI)

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.

Wantuck, P.; Watanabe, H.

1990-01-01T23:59:59.000Z

40

FLUID MECHANICS AND HEAT TRANSFER OF ELECTRON FLOW IN SEMICONDUCTORS  

E-Print Network [OSTI]

= 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

Sen, Mihir

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Thaw flow control for liquid heat transport systems  

DOE Patents [OSTI]

In a liquid metal heat transport system including a source of thaw heat for use in a space reactor power system, the thaw flow throttle or control comprises a fluid passage having forward and reverse flow sections and a partition having a plurality of bleed holes therein to enable fluid flow between the forward and reverse sections. The flow throttle is positioned in the system relatively far from the source of thaw heat.

Kirpich, Aaron S. (Broomall, PA)

1989-01-01T23:59:59.000Z

42

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

E-Print Network [OSTI]

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

Aussillous, Pascale

43

Billet Heating with the Homopolar Generator  

E-Print Network [OSTI]

Forging billets are presently brought from room temperature to forging temperature using one of three heating methods - indirect heating in a furnace, either fuel-fired or electric; direct electric resistance heating; or induction heating. Homopolar...

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

1980-01-01T23:59:59.000Z

44

MERLOT: a model for flow and heat transfer through porous media for high heat flux applications  

E-Print Network [OSTI]

MERLOT: a model for flow and heat transfer through porous media for high heat flux applications A Abstract Fusion power plant studies have found helium to be an attractive coolant based on its safety tend to provide modest heat transfer performance due to their inherently low heat capacity and heat

Raffray, A. René

45

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

DOE Patents [OSTI]

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.

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

1994-11-29T23:59:59.000Z

46

FINAL STAFF PAPER A New Generation of Combined Heat  

E-Print Network [OSTI]

onsite or exporting it to the grid. The feasibility of meeting the state's combined heat and power goals 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

47

Heat-flow reconnaissance of the Gulf Coastal Plain  

SciTech Connect (OSTI)

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.

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

1982-04-01T23:59:59.000Z

48

Model of critical heat flux in subcooled flow boiling  

E-Print Network [OSTI]

The physical phenomenon occurring before and at the critical heat flux (CHF) for subcooled flow boiling has been investigated. The first phase of this study established the basic nature of the flow structure at CHF. A ...

Fiori, Mario P.

1968-01-01T23:59:59.000Z

49

Heat Generation by Heat Pump for LNG Plants.  

E-Print Network [OSTI]

?? Abstract The LNG production plant processing natural gas from the SnÝhvit field outside Hammerfest in northern Norway utilizes heat and power produced locally withÖ (more)

Moe, BjÝrn Kristian

2011-01-01T23:59:59.000Z

50

Heat exchanger for power generation equipment  

DOE Patents [OSTI]

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.

Nirmalan, Nirm Velumylm; Bowman, Michael John

2005-06-14T23:59:59.000Z

51

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

E-Print Network [OSTI]

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...

Chen, Y.; Zhao, J.

2006-01-01T23:59:59.000Z

52

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

E-Print Network [OSTI]

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 ...

Kendall, Gail E.

1978-01-01T23:59:59.000Z

53

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

E-Print Network [OSTI]

Why Blow Away Heat? Harvest Server's Heat Using Ther- moelectric Generators Ted Tsung-Te Lai, Wei ABSTRACT This paper argues for harvesting energy from servers' wasted heat in data centers. Our approach is to distribute a large number of thermoelectric generators (TEGs) on or nearby server hotspot components whose

Huang, Polly

54

16 Heat Transfer and Air Flow in a Domestic Refrigerator  

E-Print Network [OSTI]

445 16 Heat Transfer and Air Flow in a Domestic Refrigerator Onrawee Laguerre UMR Génie Industriel........................................................................447 16.2.2 Heat Transfer and Airflow Near a Vertical Plate..................................................448 16.2.3 Heat Transfer and Airflow in Empty Closed Cavity

Paris-Sud XI, Université de

55

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

DOE Patents [OSTI]

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.

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

1998-07-21T23:59:59.000Z

56

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

DOE Patents [OSTI]

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.

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

1998-07-21T23:59:59.000Z

57

QUANTIFYING MAGNETIC RECONNECTION AND THE HEAT IT GENERATES Dana Longcope  

E-Print Network [OSTI]

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

Longcope, Dana

58

3D THERMOGRAPHY FOR QUANTIFICATION OF HEAT GENERATION RESULTING FROM  

E-Print Network [OSTI]

been used for decades by biologists and clinicians to isolate main sites of body heat loss by biologists and clinicians to isolate main sites of body heat loss and to assist with diagnosis3D THERMOGRAPHY FOR QUANTIFICATION OF HEAT GENERATION RESULTING FROM INFLAMMATION THERMOGRAPHIE 3D

Nebel, Jean-Christophe

59

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

DOE Patents [OSTI]

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.

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

1996-12-03T23:59:59.000Z

60

Sorption heat engines: simple inanimate negative entropy generators  

E-Print Network [OSTI]

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.

Anthonie W. J. Muller; Dirk Schulze-Makuch

2005-12-18T23:59:59.000Z

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Thermionic generator module with heat pipes  

SciTech Connect (OSTI)

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.

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

1993-06-15T23:59:59.000Z

62

Distributed Generation with Heat Recovery and Storage  

E-Print Network [OSTI]

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

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

2008-01-01T23:59:59.000Z

63

Heat transfer in a thermoelectric generator for diesel engines  

SciTech Connect (OSTI)

This paper discusses the design and test results obtained for a 1kW thermoelectric generator used to convert the waste thermal energy in the exhaust of a Diesel engine directly to electric energy. The paper focuses on the heat transfer within the generator and shows what had to be done to overcome the heat transfer problems encountered in the initial generator testing to achieve the output goal of 1kW electrical. The 1kW generator uses Bismuth-Telluride thermoelectric modules for the energy conversion process. These modules are also being evaluated for other waste heat applications. Some of these applications are briefly addressed.

Bass, J.C. [Hi-Z Technology, Inc., San Diego, CA (United States)

1995-12-31T23:59:59.000Z

64

MHTGR steam generator on-line heat balance, instrumentation and function  

SciTech Connect (OSTI)

Instrumentation is used to measure the Modular High Temperature Gas-Cooled Reactor (MHTGR) steam generator dissimilar metal weld temperature during start-up testing. Additional instrumentation is used to determine an on-line heat balance which is maintained during the 40 year module life. In the process of calibrating the on-line heat balance, the helium flow is adjusted to yield the optimum boiling level in the steam generator relative to the dissimilar metal weld. After calibration is complete the weld temperature measurement is non longer required. The reduced boiling level range results in less restrictive steam generator design constraints.

Klapka, R.E.; Howard, W.W.; Etzel, K.T. (General Atomics, San Diego, CA (United States)); Basol, M.; Karim, N.U. (ABB-CENP, Chattanooga, TN (United States))

1991-09-01T23:59:59.000Z

65

Heat flow and geothermal studies in the Great Plains  

SciTech Connect (OSTI)

In continental heat flow studies, sedimentary basins are usually avoided because of difficulties in obtaining thermal conductivity measurements and because temperature gradients may contain advective signals caused by moving groundwater. These problems are superimposed in the Denver, Kennedy and Williston Basins where complex geothermal gradients derive both from large contrasts among thermal conductivities of strata and from regional groundwater flow. The occurrence and magnitude of advective heat flow within the Denver, Kennedy and Williston Basins is conceptually consistent with simple models that relate groundwater flow to the piezometric surface and to subsurface structures, i.e., folds and faults. An advective heat flow of +25 mW/m/sup 2/ has been determined for an area in the eastern margin of the Denver Basin, and quantities of +35 mW/m/sup 2/ and +10 MW/m/sup 2/ have been determined respectively for parts of the southeastern and northeastern parts of the Williston Basin. A detailed analysis of bottom hole temperatures obtained from drill holes in the area of the Billings Anticline in the Williston Basin indicates that information on subsurface structures and groundwater flow may be obtained from heat flow studies. Additional information that may be derived from these heat flow studies includes: the occurrence and nature of geothermal resources, oil source rock maturation and secondary migration of petroleum, formation and deposition of strata-bound ores. 43 references.

Gosnold, W.D.; Fischer, D.W.

1985-12-01T23:59:59.000Z

66

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...

67

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

Open Energy Info (EERE)

Resource-Reservoir Investigations Based On Heat Flow And Thermal Gradient Data For The United States Jump to: navigation, search OpenEI Reference LibraryAdd to library Report:...

68

Enhanced two phase flow in heat transfer systems  

DOE Patents [OSTI]

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.

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

2013-12-03T23:59:59.000Z

69

Heating Cooling Flows with Weak Shock Waves  

E-Print Network [OSTI]

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.

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

2005-11-05T23:59:59.000Z

70

Power Generation From Waste Heat Using Organic Rankine Cycle Systems  

E-Print Network [OSTI]

Many efforts are currently being pursued to develop and implement new energy technologies aimed at meeting our national energy goals The use of organic Rankine cycle engines to generate power from waste heat provides a near term means to greatly...

Prasad, A.

1980-01-01T23:59:59.000Z

71

Heat transfer and fluid flow characteristics in various micro devices for the development of micro absorption heat pump systems.  

E-Print Network [OSTI]

??This thesis presents a series of studies on heat transfer and fluid flow characteristics in various micro devices for the development of micro absorption heatÖ (more)

Hu, Jinshan

2007-01-01T23:59:59.000Z

72

Control of reactor coolant flow path during reactor decay heat removal  

DOE Patents [OSTI]

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.

Hunsbedt, Anstein N. (Los Gatos, CA)

1988-01-01T23:59:59.000Z

73

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

SciTech Connect (OSTI)

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.

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

1991-01-01T23:59:59.000Z

74

Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas-  

Open Energy Info (EERE)

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 Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat Jump to:Photon Place:NetHealth Division |Hays,Community CollegeFeatures

75

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

E-Print Network [OSTI]

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

Xu, Xianfan

76

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

77

Finned Tube With Vortex Generators For A Heat Exchanger.  

DOE Patents [OSTI]

A system for and method of manufacturing a finned tube for a heat exchanger is disclosed herein. A continuous fin strip is provided with at one pair of vortex generators. A tube is rotated and linearly displaced while the continuous fin strip with vortex generators is spirally wrapped around the tube.

Sohal, Manohar S. (Idaho Falls, ID); O'Brien, James E. (Idaho Falls, ID)

2005-12-20T23:59:59.000Z

78

Optimal selection of on-site generation with combined heat and power applications  

E-Print Network [OSTI]

Modeling with Combined Heat and Power Applications. LBNL-Tax on Microgrid Combined Heat and Power Adoption. JournalGeneration with Combined Heat and Power Applications Afzal

Siddiqui, Afzal S.; Marnay, Chris; Bailey, Owen; Hamachi LaCommare, Kristina

2004-01-01T23:59:59.000Z

79

Generating expansion model incorporating compact DC power flow equations  

SciTech Connect (OSTI)

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.

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

80

Brine flow in heated geologic salt.  

SciTech Connect (OSTI)

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.

Kuhlman, Kristopher L.; Malama, Bwalya

2013-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Heat flow and geothermal studies in the state of Washington  

SciTech Connect (OSTI)

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.

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

1985-08-01T23:59:59.000Z

82

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

E-Print Network [OSTI]

Laminar, two-dimensional, constant-property numerical simulations of flat tube heat exchanger devices operating in flow regimes in which self-sustained oscillations occur were performed. The unsteady flow regimes were transition flow regimes...

Fullerton, Tracy

2012-02-14T23:59:59.000Z

83

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)

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.

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

84

New geothermal heat extraction process to deliver clean power generation  

ScienceCinema (OSTI)

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.

Pete McGrail

2012-12-31T23:59:59.000Z

85

Friction-Induced Fluid Heating in Nanoscale Helium Flows  

SciTech Connect (OSTI)

We investigate the mechanism of friction-induced fluid heating in nanoconfinements. Molecular dynamics simulations are used to study the temperature variations of liquid helium in nanoscale Poiseuille flows. It is found that the fluid heating is dominated by different sources of friction as the external driving force is changed. For small external force, the fluid heating is mainly caused by the internal viscous friction in the fluid. When the external force is large and causes fluid slip at the surfaces of channel walls, the friction at the fluid-solid interface dominates over the internal friction in the fluid and is the major contribution to fluid heating. An asymmetric temperature gradient in the fluid is developed in the case of nonidentical walls and the general temperature gradient may change sign as the dominant heating factor changes from internal to interfacial friction with increasing external force.

Li Zhigang [Department of Mechanical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

2010-05-21T23:59:59.000Z

86

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)]

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

Blackwell, D.D. and others

87

PYROLYSIS OF METHANE IN A SUPERSONIC, ARC-HEATED FLOW  

E-Print Network [OSTI]

1 PYROLYSIS OF METHANE IN A SUPERSONIC, ARC-HEATED FLOW F.K. Lu,* C.M. Roseberry, J.M. Meyers and D arc pyrolysis of methane at supersonic conditions, representative of conditions in the reformer- cate the feasibility of arc pyrolysis of methane. Introduction he high specific enthalpy of combustion

Texas at Arlington, University of

88

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

E-Print Network [OSTI]

Thermoelectric Generators for Automotive Waste Heat Recovery Systems Part I: Numerical Modeling telluride TEMs. Key words: Thermoelectric generators, waste heat recovery, automotive exhaust, skutterudites bismuth telluride are considered for thermoelectric modules (TEMs) for conversion of waste heat from

Xu, Xianfan

89

Development of Design Criteria for Fluid Induced Structural Vibration in Steam Generators and Heat Exchangers  

SciTech Connect (OSTI)

OAK-B135 Flow-induced vibration in heat exchangers has been a major cause of concern in the nuclear industry for several decades. Many incidents of failure of heat exchangers due to apparent flow-induced vibration have been reported through the USNRC incident reporting system. Almost all heat exchangers have to deal with this problem during their operation. The phenomenon has been studied since the 1970s and the database of experimental studies on flow-induced vibration is constantly updated with new findings and improved design criteria for heat exchangers. In the nuclear industry, steam generators are often affected by this problem. However, flow-induced vibration is not limited to nuclear power plants, but to any type of heat exchanger used in many industrial applications such as chemical processing, refrigeration and air conditioning. Specifically, shell and tube type heat exchangers experience flow-induced vibration due to the high velocity flow over the tube banks. Flow-induced vibration in these heat exchangers leads to equipment breakdown and hence expensive repair and process shutdown. The goal of this research is to provide accurate measurements that can help modelers to validate their models using the measured experimental parameters and thereby develop better design criteria for avoiding fluid-elastic instability in heat exchangers. The research is divided between two primary experimental efforts, the first conducted using water alone (single phase) and the second using a mixture of air or steam and water as the working fluid (two phase). The outline of this report is as follows: After the introduction to fluid-elastic instability, the experimental apparatus constructed to conduct the experiments is described in Chapter 2 along with the measurement procedures. Chapter 3 presents results obtained on the tube array and the flow loop, as well as techniques used in data processing. The project performance is described and evaluated in Chapter 4 followed by a discussion of publications and presentations relevant to the project in Chapter 5, while the conclusions and recommendations for future work are presented in Chapter 6.

Catton, Ivan; Dhir, Vijay K.; Alquaddoomi, O.S.; Mitra, Deepanjan; Adinolfi, Pierangelo

2004-03-26T23:59:59.000Z

90

.Heat Generation Patterns and Temperature Profiles in_ Electroslag Welding  

E-Print Network [OSTI]

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

Eagar, Thomas W.

91

Probing and Controlling Photothermal Heat Generation in Plasmonic Nanostructures  

E-Print Network [OSTI]

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

Simaan, Nabil

92

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

E-Print Network [OSTI]

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.

Nasser Mohamed Ahmed

2007-10-10T23:59:59.000Z

93

Estimates of heat flow from Cenozoic seafloor using global depth and age data  

E-Print Network [OSTI]

-independent estimate of the total heat output of Cenozoic seafloor is 18.6 to 20.5 TW, which leads to a global output: Oceanic heat flow; Global heat budget; Subsidence rate 1. Introduction The total heat output of the EarthEstimates of heat flow from Cenozoic seafloor using global depth and age data Meng Wei , David

Sandwell, David T.

94

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

E-Print Network [OSTI]

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

Kosuga, Yusuke

2012-01-01T23:59:59.000Z

95

COMPUTATION OF TWO-PHASE FLOW IN STEAM GENERATOR  

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

96

Microcomputer analysis of regenerative heat exchangers for oscillating flow  

SciTech Connect (OSTI)

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.

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

1987-03-01T23:59:59.000Z

97

Spherical collapse with heat flow and without horizon  

E-Print Network [OSTI]

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.

A. Banerjee; S. Chatterjee; N. Dadhich

2002-09-10T23:59:59.000Z

98

Heat Exchangers for the Next Generation of Nuclear Reactors  

SciTech Connect (OSTI)

The realisation that fossil fuel resources are finite, the associated rising price and a growing concern about greenhouse gas emissions, has resulted in renewed interest in nuclear energy. Generation IV and other programmes are looking at a variety of new reactors. These reactors vary in type from Very High Temperature Gas Cooled Reactors (VHTR) to Liquid Metal Fast Reactors (LFR and SFR) with cooling mediums that include: - Helium, - Supercritical carbon dioxide, - Sodium, - Lead, - Molten salts. In addition interest is not just focused on production of electrical power with an efficiency greater than that associated with the Rankine Cycle (typically 30 -35%); there is now genuine interest in nuclear energy as a heat source for hydrogen production, via the Sulphur Iodine Process (SI) or high temperature electrolysis. The production of electrical power at higher efficiency via a Brayton Cycle, and hydrogen production requires both heat at higher temperatures, up to 1000 deg C and high effectiveness heat exchange to transfer the heat to either the power or process cycle. This presents new challenges for the heat exchangers. If plant efficiencies are to be improved there is a need for: - High effectiveness heat exchange at minimal pressure drop; - Compact heat exchange to improve safety and economics; - An ability to build coded heat exchangers in a variety of nickel based alloys, oxide dispersion strengthened alloys (ODS) and ceramic materials to address the temperature, life and corrosion issues associated with these demanding duties. Heatric has already given consideration to many of these challenges. Their Print Circuit Heat Exchanger (PCHE) and Formed Plate Heat Exchanger (FPHE) technology which are commercially available today, will fulfill all of the duties up to temperatures of 950 deg C. In addition products currently under development will further increase the temperature and pressure range, while offering greater corrosion resistance and operational life. This paper outlines the challenges for the heat exchangers and the development required, with particular attention given to material selection. It is further the objective of this study to demonstrate that heat exchangers such as PCHE and FPHE are able to meet the above challenges. (authors)

Xiuqing, Li; Le Pierres, Renaud; Dewson, Stephen John [Heatric Division of Meggitt (UK) Ltd., 46 Holton Road, Holton Heath, Poole, Dorset BH16 6LT (United Kingdom)

2006-07-01T23:59:59.000Z

99

Efficiency and Air Quality Implications of Distributed Generation and Combined Heat  

E-Print Network [OSTI]

in a manner that recovers waste heat for heating and/or cooling--called combined heat and power-- negativeEfficiency and Air Quality Implications of Distributed Generation and Combined Heat and Power environmental impacts can be decreased. Distributed generation/combined heat and power has been identified

100

The regional geothermal heat flow regime of the north-central Gulf of Mexico continental slope.  

E-Print Network [OSTI]

??Eighty-eight oil and gas wells located in the Texas-Louisiana continental slope were analyzed to obtain heat flow and geothermal gradient values. Present-day geothermal heat flowÖ (more)

Jones, Michael S

2003-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

A visualization comparison of convective flow boiling heat transfer augmentation devices  

E-Print Network [OSTI]

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...

Lundy, Brian Franklin

1998-01-01T23:59:59.000Z

102

Heat transfer to a fluid flowing in an annulus  

E-Print Network [OSTI]

. ii I ~ DIMENSIONS AND SYMBOLS o ~ ~ ~ . ~ ~ ~ ~ I II e INTRODUCTION AND THEORY ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 3 IXI e APPARATUS AND PROCEDURES ~ ~ e ~ ~ ~ ~ ~ ~ ~ ~ 7 XV o RESULTS ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ e ~ ~ ~ ~ 17 V, DXSCUSSION OF RESULTS... of times 0 Prandtl nnnber~ e~& dimensionless initial temperature oi' surfaoe and fluids% D equivalent diameter& Di g~ L Q - volume flow rate~ L3/T V~ mass velooity, FT/L3 6 mass floe rate~ FT/L IMTRODUCTIOR AND THEORY This thesis comprises heat tz...

Logan, Earl

2012-06-07T23:59:59.000Z

103

RESEARCH ARTICLE Time resolved measurements of the flow generated  

E-Print Network [OSTI]

relevance, the generated flow field is interesting fluid mechanically as it incorporates high velocities. The flow is interesting from a fluid mechanical perspective as it includes high spatial gradients-structure interactions. Forces are a function of the biomechanical forces within the fish and the fluid mechanical

Wainwright, Peter C.

104

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

E-Print Network [OSTI]

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

Le Roy, Robert J.

105

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

E-Print Network [OSTI]

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

Abdou, Mohamed

106

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

E-Print Network [OSTI]

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

California at Los Angeles, University of

107

Numerical simulations of heat transfer in plane channel flow Najla EL GHARBI 1, 3, a  

E-Print Network [OSTI]

Numerical simulations of heat transfer in plane channel flow Najla EL GHARBI 1, 3, a , Rafik ABSI 2 abenzaoui@gmail.com Keywords: turbulent flows, heat transfer, forced convection, low Reynolds number model data for Re = 150. Introduction Turbulent flow with heat transfer mechanism is of great importance from

Paris-Sud XI, Université de

108

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

109

EXERGY ANALYSIS AND ENTROPY GENERATION MINIMIZATION OF THERMOELECTRIC WASTE HEAT RECOVERY FOR ELECTRONICS  

E-Print Network [OSTI]

Energy recovery from waste heat is attracting more and more attention. All electronic systems consume electricity but only a fraction of it is used for information processing and for human interfaces, such as displays. Lots of energy is dissipated as heat. There are some discussions on waste heat recovery from the electronic systems such as laptop computers. However the efficiency of energy conversion for such utilization is not very attractive due to the maximum allowable temperature of the heat source devices. This leads to very low limits of Carnot efficiency. In contrast to thermodynamic heat engines, Brayton cycle, free piston Stirling engines, etc., authors previously reported that thermoelectric (TE) can be a cost-effective device if the TE and the heat sink are co-optimized, and if some parasitic effects could be reduced. Since the heat already exists and it is free, the additional cost and energy payback time are the key measures to evaluate the value of the energy recovery system. In this report, we will start with the optimum model of the TE power generation system. Then, theoretical maximum output, cost impact and energy payback are evaluated in the examples of electronics system. Entropy Generation Minimization (EGM) is a method already familiar in thermal management of electronics. The optimum thermoelectric waste heat recovery design is compared with the EGM approach. Exergy analysis evaluates the useful energy flow in the optimum TE system. This comprehensive analysis is used to predict the potential future impact of the TE material development, as the dimensionless figure-ofmerit (ZT) is improved.

Kazuaki Yazawa; Ali Shakouri

110

Generating Geodesic Flows and Supergravity Solutions  

E-Print Network [OSTI]

We consider the geodesic motion on the symmetric moduli spaces that arise after timelike and spacelike reductions of supergravity theories. The geodesics correspond to timelike respectively spacelike $p$-brane solutions when they are lifted over a $p$-dimensional flat space. In particular, we consider the problem of constructing \\emph{the minimal generating solution}: A geodesic with the minimal number of free parameters such that all other geodesics are generated through isometries. We give an intrinsic characterization of this solution in a wide class of orbits for various supergravities in different dimensions. We apply our method to three cases: (i) Einstein vacuum solutions, (ii) extreme and non-extreme D=4 black holes in N=8 supergravity and their relation to N=2 STU black holes and (iii) Euclidean wormholes in $D\\geq 3$. In case (iii) we present an easy and general criterium for the existence of regular wormholes for a given scalar coset.

E. Bergshoeff; W. Chemissany; A. Ploegh; M. Trigiante; T. Van Riet

2008-10-30T23:59:59.000Z

111

Numerical investigation of electric heating impacts on solid/liquid glass flow patterns.  

SciTech Connect (OSTI)

A typical glass furnace consists of a combustion space and a melter. Intense heat is generated from the combustion of fuel and air/oxygen in the combustion space. This heat is transferred mainly by radiation to the melter in order to melt sand and cullet (scrap glass) eventually creating glass products. Many furnaces use electric boosters to enhance glass melting and increase productivity. The coupled electric/combustion heat transfer patterns are key to the glass making processes. The understanding of the processes can lead to the improvement of glass quality and furnace efficiency. The effects of electrical boosting on the flow patterns and heat transfer in a glass melter are investigated using a multiphase Computational Fluid Dynamics (CFD) code with addition of an electrical boosting model. The results indicate that the locations and spacing of the electrodes have large impacts on the velocity and temperature distributions in the glass melter. With the same total heat input, the batch shape (which is determined by the overall heat transfer and the batch melting rate) is kept almost the same. This indicates that electric boosting can be used to replace part of heat by combustion. Therefore, temperature is lower in the combustion space and the life of the furnace can be prolonged. The electric booster can also be used to increase productivity without increasing the furnace size.

Chang, S. L.; Zhou, C. Q.; Golchert, B.

2002-07-02T23:59:59.000Z

112

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...

113

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

SciTech Connect (OSTI)

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.

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

1991-06-01T23:59:59.000Z

114

Salt disposal of heat-generating nuclear waste.  

SciTech Connect (OSTI)

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.

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

2011-01-01T23:59:59.000Z

115

Dynamic stability experiments in sodium-heated steam generators. [LMFBR  

SciTech Connect (OSTI)

Seventy-two dynamic stability tests were performed in the sodium-heated boiling-water test facility at Argonne National Laboratory. A full-scale LMFBR steam generator tube was employed as the test section operating over the water parameter ranges of 6.9 to 15.9 MPa pressure and 170 to 800 kg/m/sup 2/.s mass flux. The stability thresholds from the test compared well to the predictions of a modified version of a correlation equation recently published by other investigators. Typical experimental data and the modified correlation equation are presented.

France, D.M.; Roy, R.; Carlson, R.D.; Chiang, T.

1984-01-01T23:59:59.000Z

116

Geothermal Heat Flow and Existing Geothermal Plants | Department of Energy  

Office of Environmental Management (EM)

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelinesProvedDecember 2005DepartmentDecember U.S.FinancialofFuelDepartmentGeothermal Heat Flow

117

Couette flow regimes with heat transfer in rarefied gas  

SciTech Connect (OSTI)

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.

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

118

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

SciTech Connect (OSTI)

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.

M.A. Plummer

2013-09-01T23:59:59.000Z

119

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

E-Print Network [OSTI]

Heat Transfer Research 44(1), 1­30 (2013) ENTROPY GENERATION ANALYSIS FOR A PULSATING HEAT­vapor phase 2 Kim, Zhang, & Choi Heat Transfer Research NOMENCLATURE A area, m2 Qin,s,l sensible heat transfer into cp specific heat at constant liquid slug, W pressure, Qout,s,l sensible heat transfer out cv specific

Zhang, Yuwen

120

Numerical heat conduction in hydrodynamical models of colliding hypersonic flows  

E-Print Network [OSTI]

Hydrodynamical models of colliding hypersonic flows are presented which explore the dependence of the resulting dynamics and the characteristics of the derived X-ray emission on numerical conduction and viscosity. For the purpose of our investigation we present models of colliding flow with plane-parallel and cylindrical divergence. Numerical conduction causes erroneous heating of gas across the contact discontinuity which has implications for the rate at which the gas cools. We find that the dynamics of the shocked gas and the resulting X-ray emission are strongly dependent on the contrast in the density and temperature either side of the contact discontinuity, these effects being strongest where the postshock gas of one flow behaves quasi-adiabatically while the postshock gas of the other flow is strongly radiative. Introducing additional numerical viscosity into the simulations has the effect of damping the growth of instabilities, which in some cases act to increase the volume of shocked gas and can re-he...

Parkin, E R

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Numerical method for fluid flow and heat transfer in magnetohydrodynamic flow  

SciTech Connect (OSTI)

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).

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

1989-03-01T23:59:59.000Z

122

Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions  

E-Print Network [OSTI]

Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions by Carl, Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions KTH Nuclear Reactor power is limited by a phenomenon called critical heat flux (CHF). It appears as a sudden detoriation

Haviland, David

123

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

E-Print Network [OSTI]

Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S the dynamical effects from the heat transfer process. The fluid flow in an enclosed disk system with axial with heat transfer along the stator, which corresponds to the experiment of Djaoui et al. [2]. Our results

Boyer, Edmond

124

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

E-Print Network [OSTI]

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

Graaf, Martin de

125

Finite element solutions of heat transfer in molten polymer flow in tubes with viscous dissipation  

E-Print Network [OSTI]

Finite element solutions of heat transfer in molten polymer flow in tubes with viscous dissipation the results of finite element analysis of a heat transfer problem of flowing polymer melts in a tube­Nusselt problem 1. Introduction Heat transfer to incompressible viscous non-Newto- nian fluids is a problem

Wei, Dongming

126

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

E-Print Network [OSTI]

Friction and Heat Transfer Characteristics of Silica and CNT Nanofluids in a Tube Flow MILIVOJE M@niu.edu * www.kostic.niu.edu Abstract: - An apparatus for exploring friction and heat transfer characteristics flow. Initial turbulent friction and heat transfer measurements for silica and carbon nanotube (CNT

Kostic, Milivoje M.

127

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

E-Print Network [OSTI]

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

Kandlikar, Satish

128

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

E-Print Network [OSTI]

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

Boyer, Edmond

129

The effects of topology upon fluid-flow and heat-transfer within cellular copper structures  

E-Print Network [OSTI]

and packed beds, but also a function of orientation (open area ratio). The overall heat transfer dependsThe effects of topology upon fluid-flow and heat-transfer within cellular copper structures J. Tian February 2004 Available online 20 March 2004 Abstract The fluid-flow and heat-transfer features of cellular

Wadley, Haydn

130

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

E-Print Network [OSTI]

High-power ELF radiation generated by modulated HF heating of the ionosphere can cause Earthquakes, the HAARP heater is the most powerful ionospheric heater, with 3.6GW of effective power using HF heating, Cyclones and localized heating Fran De Aquino Maranhao State University, Physics Department, S

Paris-Sud XI, Université de

131

Numerical Simulations of Dynamos Generated in Spherical Couette Flows  

E-Print Network [OSTI]

at generating a self-sustained magnetic field. No dynamo action occurs for axisymmetric flow while we always, Forest et al., 2002). No self-sustained magnetic fields were observed in the parameter regime where of ferromagnetic impellers, a self-sustained magnetic field has been observed in the Von K¬īarm¬īan Sodium (VKS

Boyer, Edmond

132

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

SciTech Connect (OSTI)

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.

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

133

An experimental investigation of critical heat flux in subcooled internal flow  

E-Print Network [OSTI]

An experimental investigation has been conducted to determine the critical heat flux for subcooled refrigerant-11 and refrigerant-113 flowing upward in a vertical cylindrical tube. Critical heat flux (CHF) values are determined for a range of tube...

Shatto, Donald Patrick

1997-01-01T23:59:59.000Z

134

FLOW AND HEAT TRANSFER IN MICROFLUIDIC DEVICES WITH APPLICATION TO OPTOTHERMAL  

E-Print Network [OSTI]

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

Bahrami, Majid

135

A Variable Refrigerant Flow Heat Pump Computer Model in EnergyPlus  

SciTech Connect (OSTI)

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.

Raustad, Richard A. [Florida Solar Energy Center

2013-01-01T23:59:59.000Z

136

Generation of mirage effect by heated carbon nanotube thin film  

SciTech Connect (OSTI)

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.

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

137

Photometric studies of heat flow at the photosphere  

SciTech Connect (OSTI)

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.

Foukal, P.

1984-05-01T23:59:59.000Z

138

Ad hoc continuum-atomistic thermostat for modeling heat flow in molecular dynamics simulations  

E-Print Network [OSTI]

Ad hoc continuum-atomistic thermostat for modeling heat flow in molecular dynamics simulations J 2004) An ad hoc thermostating procedure that couples a molecular dynamics (MD) simulation

Brenner, Donald W.

139

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

E-Print Network [OSTI]

pumps, heat pipes, cold thermal energy storage Ron Zevenhoven √?bo Akademi University Thermal and Flow for heating is referred to as a heat pump (mostly based on a vapour-compression cycle) Heat pumps make use electricity!) for heating and air conditioning purposes Heat pumps became popular in the 1970s

Zevenhoven, Ron

140

Development of Design Criteria for Fluid Induced Structural Vibrations in Steam Generators and Heat Exchangers  

SciTech Connect (OSTI)

Flow-induced vibration in heat exchangers has been a major cause of concern in the nuclear industry for several decades. Many incidents of failure of heat exchangers due to apparent flow-induced vibration have been reported through the USNRC incident reporting system. Almost all heat exchangers have to deal with this problem during their operation. The phenomenon has been studied since the 1970s and the database of experimental studies on flow-induced vibration is constantly updated with new findings and improved design criteria for heat exchangers.

Uvan Catton; Vijay K. Dhir; Deepanjan Mitra; Omar Alquaddoomi; Pierangelo Adinolfi

2004-04-06T23:59:59.000Z

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

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

SciTech Connect (OSTI)

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.

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

142

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

E-Print Network [OSTI]

??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 flueÖ (more)

Latcham, Jacob G. (Jacob Greco)

2009-01-01T23:59:59.000Z

143

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

E-Print Network [OSTI]

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 ...

Latcham, Jacob G. (Jacob Greco)

2009-01-01T23:59:59.000Z

144

Anisotropic flow generated by hard partons in medium  

E-Print Network [OSTI]

Hard partons which are produced copiously in nuclear collisions at the LHC, deposit most of their energy and momentum into the surrounding quark-gluon plasma. We show that this generates streams in the plasma and contributes importantly to flow anisotropies. With the help of event-by-event three-dimensional perfect hydrodynamic simulations we calculate the observable azimuthal anisotropies of hadronic distributions and show that the proposed mechanism is capable of generating non-negligible part of the observed signal. Hence, it must be taken into account in quantitative studies in which one tries to extract the values of viscosities from the comparison of simulated results with measured data.

Tomasik, Boris

2015-01-01T23:59:59.000Z

145

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

E-Print Network [OSTI]

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

Maruyama, Shigeo

146

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

SciTech Connect (OSTI)

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.

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

2010-05-01T23:59:59.000Z

147

Forced convective flow and heat transfer of upward cocurrent air-water slug flow in vertical plain and swirl tubes  

SciTech Connect (OSTI)

This experimental study comparatively examined the two-phase flow structures, pressured drops and heat transfer performances for the cocurrent air-water slug flows in the vertical tubes with and without the spiky twisted tape insert. The two-phase flow structures in the plain and swirl tubes were imaged using the computerized high frame-rate videography with the Taylor bubble velocity measured. Superficial liquid Reynolds number (Re{sub L}) and air-to-water mass flow ratio (AW), which were respectively in the ranges of 4000-10000 and 0.003-0.02 were selected as the controlling parameters to specify the flow condition and derive the heat transfer correlations. Tube-wise averaged void fraction and Taylor bubble velocity were well correlated by the modified drift flux models for both plain and swirl tubes at the slug flow condition. A set of selected data obtained from the plain and swirl tubes was comparatively examined to highlight the impacts of the spiky twisted tape on the air-water interfacial structure and the pressure drop and heat transfer performances. Empirical heat transfer correlations that permitted the evaluation of individual and interdependent Re{sub L} and AW impacts on heat transfer in the developed flow regions of the plain and swirl tubes at the slug flow condition were derived. (author)

Chang, Shyy Woei [Thermal Fluids Laboratory, National Kaohsiung Marine University, No. 142, Haijhuan Road, Nanzih District, Kaohsiung City 81143 (China); Yang, Tsun Lirng [Department of Marine Engineering, National Kaohsiung Marine University, No. 142, Haijhuan Road, Nanzih District, Kaohsiung City 81143 (China)

2009-10-15T23:59:59.000Z

148

NUMERICAL STUDY OF FLUID FLOW AND HEAT TRANSFER OVER A SERIES OF IN-LINE NONCIRCULAR  

E-Print Network [OSTI]

NUMERICAL STUDY OF FLUID FLOW AND HEAT TRANSFER OVER A SERIES OF IN-LINE NONCIRCULAR TUBES CONFINED, Texas A&M University, College Station, Texas, USA Two-dimensional steady developing fluid flow and heat-volume technique. Grid independence study was carried out by running the developed code for several different grid

Bahaidarah, Haitham M.

149

Taylor bubble-train flows and heat transfer in the context of Pulsating Balkrishna Mehta, Sameer Khandekar  

E-Print Network [OSTI]

Taylor bubble-train flows and heat transfer in the context of Pulsating Heat Pipes Balkrishna Mehta Nusselt number Heat transfer enhancement a b s t r a c t Understanding the performance of Pulsating Heat Pipes (PHPs) requires spatio-temporally coupled, flow and heat transfer information during the self

Khandekar, Sameer

150

Large Deviations in Stochastic Heat-Conduction Processes Provide a Gradient-Flow Structure for Heat Conduction  

E-Print Network [OSTI]

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 $m$, a Generalized Brownian Energy Process, and the Kipnis-Marchioro-Presutti 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 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 $-\\log \\rho$; they involve dissipation or mobility terms of order $\\rho^2$ for the linear heat equation, and a nonlinear function of $\\rho$ for the nonlinear heat equation.

Mark A. Peletier; Frank Redig; Kiamars Vafayi

2014-03-19T23:59:59.000Z

151

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

E-Print Network [OSTI]

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...

Soti, Atul Kumar; Sheridan, John

2015-01-01T23:59:59.000Z

152

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

SciTech Connect (OSTI)

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.

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

2013-05-01T23:59:59.000Z

153

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

E-Print Network [OSTI]

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

Boyer, Edmond

154

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

E-Print Network [OSTI]

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

Kandlikar, Satish

155

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

E-Print Network [OSTI]

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

Robles-Kelly, Antonio

156

Abstract--The deployment of small (generators, heat and electrical storage, efficiency investments,  

E-Print Network [OSTI]

1 Abstract--The deployment of small (generators, heat and electrical storage-CAM], extended to incorporate electrical storage options. DER-CAM chooses annual energy bill minimizing systems management systems, cogeneration, cooling, cost optimal control, dispersed storage and generation

Guillas, Serge

157

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

SciTech Connect (OSTI)

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.

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

2009-03-01T23:59:59.000Z

158

ARC-HEATED GAS FLOW EXPERIMENTS FOR HYPERSONIC PROPULSION  

E-Print Network [OSTI]

was extensively developed for the purpose of eventually performing experiments simulating scramjet engine flow

Texas at Arlington, University of

159

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

E-Print Network [OSTI]

FARM NET INCOME IMPACT OF SWITCHGRASS PRODUCTION AND CORN STOVER COLLECTION FOR HEAT AND POWER and Corn Stover Collection for Heat and Power Generation Mitchell A. Myhre Advisor: Associate Professor heat and electric power. To perform this analysis, yield and production potentials were explored

Wisconsin at Madison, University of

160

SOOT GENERATION IN FIRES: AN IMPORTANT PARAMETER FOR ACCURATE CALCULATION OF HEAT RELEASE  

E-Print Network [OSTI]

states that heat of complete combustion per unit mass of oxygen consumed is approximately constant similarly states that heat of complete combustion per unit mass of carbon dioxide generated is approximately constant for most organic liquid, gaseous and solid compounds [1]. The heat of combustion per unit mass

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

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

DOE Patents [OSTI]

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.

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

1996-11-05T23:59:59.000Z

162

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

E-Print Network [OSTI]

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

Robertson, Meldrum

163

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

DOE Patents [OSTI]

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.

Labinov, Solomon D.; Christian, Jeffrey E.

2003-10-07T23:59:59.000Z

164

Novel thermoelectric generator for stationary power waste heat recovery .  

E-Print Network [OSTI]

??Internal combustion engines produce much excess heat that is vented to the atmosphere through the exhaust fluid. Use of solid-state thermoelectric (TE) energy conversion technologyÖ (more)

Engelke, Kylan Wynn.

2010-01-01T23:59:59.000Z

165

Air flow in a high aspect ratio heat sink  

E-Print Network [OSTI]

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 ...

Allison, Jonathan Michael

2010-01-01T23:59:59.000Z

166

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

SciTech Connect (OSTI)

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.

Ali S. Siahpush; John Crepeau; Piyush Sabharwall

2013-07-01T23:59:59.000Z

167

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 : Thermoelectric generator, Solar heat concentrator, Carnot efficiency I - Introduction The global energy crisis the junctions of two different materials. For a TEG to supply a significant amount of power, several thermo

168

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

SciTech Connect (OSTI)

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.

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

169

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

E-Print Network [OSTI]

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

Pilon, Laurent

170

Original article Influence of heating conditions in continuous-flow  

E-Print Network [OSTI]

, 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

Paris-Sud XI, Universitť de

171

OSCILLATORY FLOW FORCED CONVECTION IN MICRO HEAT SPREADERS  

E-Print Network [OSTI]

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

Beskok, Ali

172

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

E-Print Network [OSTI]

Steam 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 words: Steam Generator, Two-phase Flow, Finite element Email address: Marc.Grandotto@cea.fr (M

Paris-Sud XI, Université de

173

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

SciTech Connect (OSTI)

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.

Pferdehirt, W.; Kron, N. Jr.

1980-11-01T23:59:59.000Z

174

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

E-Print Network [OSTI]

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

Ghajar, Afshin J.

175

Fusion Engineering and Design 81 (2006) 549553 Numerical analysis of MHD flow and heat transfer in a  

E-Print Network [OSTI]

Fusion Engineering and Design 81 (2006) 549­553 Numerical analysis of MHD flow and heat transfer January 2006 Abstract MHD flow and heat transfer have been analyzed for a front poloidal channel blanket; Magnetohydrodynamics; Heat transfer 1. Introduction Using flow channel inserts (FCIs) made

Abdou, Mohamed

176

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

DOE Patents [OSTI]

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.

Meisner, Gregory P

2013-10-08T23:59:59.000Z

177

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

Open Energy Info (EERE)

subsurface associated with the Coso Geothermal Area, is being transferred by a conductive heat transfer mechanism with a value of approximately 15 mucalcm2-sec. This is typical...

178

Numerical modeling of deep groundwater flow and heat transport in the Williston Basin  

SciTech Connect (OSTI)

A numerical modeling approach has been used to evaluate quantitatively the effects of fluid flow on contemporary heat flow in an intracratonic basin. The authors have selected the Williston basin for this hydrodynamic study because of the opportunity it presents to assess the relation of deep groundwater flow to basin geothermics and the associated features of diagenesis and petroleum accumulation. The finite element method is used to solve the coupled equations of fluid flow and heat transport in two-dimensional sections of the basin. Both the fluid- and heat-flow regime are assumed to be at steady state, and the fluid flow is driven primarily by the water-table relief which is taken to be a subdued replica of land-surface topography. Buoyancy forces may also affect flow through fluid density gradients created by temperature and salinity effects. Three southwest-northwest oriented sections across the basin were modeled using available and estimated parameter data. The predicted flow patterns are most strongly affected by the topography, but the Devonian salt unit and Cretaceous shale unit exert some control. Cross-formational flow is especially important near the downdip, solution edge of the salt beds. Flow rates rarely exceed 0.5 m/year in the deep-central part of the basin, yet there does exist a marked effect on heat flow, albeit subdued by the blanket effect of the low-permeability Cretaceous shales. The regional effect of the topography-driven flow system is reflected in present-day salinity patterns and heat-flow data.

Garven, G.; Vigrass, L.

1985-01-01T23:59:59.000Z

179

Heat Flow of Biharmonic Maps in Dimensions Four and Its Application  

E-Print Network [OSTI]

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†...

2007-06-07T23:59:59.000Z

180

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

E-Print Network [OSTI]

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...

Westheimer, David Thomas

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

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

E-Print Network [OSTI]

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 ...

Laverty, W. F.

1964-01-01T23:59:59.000Z

182

Numerical study of flow and heat transfer in 3D serpentine channels using colocated grids  

E-Print Network [OSTI]

and average Nusselt number. The numerical code developed was validated by solving for fully developed flow and heat transfer in a square straight channel. Grid-independent solution was established for a reference case of serpentine channel with the highest...

Chintada, Sailesh Raju

1998-01-01T23:59:59.000Z

183

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

Open Energy Info (EERE)

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

184

Influence of surface heating on the boundary layer stability of flows with favorable pressure gradients  

E-Print Network [OSTI]

INFLUENCE OF SURFACE HEATING ON THE BOUNDARY LAYER STABILITY OF FLOWS WITH FAVORABI E PRESSURE GRADIENTS A Thesis by DAVID BRIAN LANDRUM Submitted to the Graduate College of Texas AAM University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE August 1986 Major Subject: Aerospace Engineering INFLUENCE OF SURFACE HEATING ON THE BOUNDARY LAYER STABILITY OF FLOWS WITH FAVORABLE PRESSURE GRADIENTS A Thesis by DAVID BRIAN LANDRUM Approved as to style and content...

Landrum, David Brian

2012-06-07T23:59:59.000Z

185

Downward flow of water with entrained air in a nonuniformaly heated subdivided annulus  

SciTech Connect (OSTI)

This paper describes an experimental study in which water was fed to a vertical annulus, entraining air in downward flow. The annulus was subdivided by longitudinal fins into four subchannels and was heated with an azimuthally varying heat flux. A bypass was provided to simulate flow in parallel channels. For steady liquid flow, inlet temperature, and pressure boundary conditions, the power was increased until critical heat flux was reached. Overheating characteristics were grouped according to the prevailing flow pattern. In annular flows (j{sub L} < 0.3 m/s) overheating of the whole test section occurs when steam production causes countercurrent flooding. In intermittent flows (0.3 < j{sub L} < 0.9 m/s) the overheating is confined to a portion of the hot subchannel. The mechanism is postulated to be stagnation of a large bubble. In bubble flows (0.9 m/s < j{sub L}) overheating occurs by diverting inlet flow to the bypass and again involves the whole test section. Except at the very lowest flow rates, critical heat flux occurs when the effluent liquid temperature is below saturation.

Johnston, B.S.; May, C.P.

1992-10-01T23:59:59.000Z

186

Downward flow of water with entrained air in a nonuniformaly heated subdivided annulus  

SciTech Connect (OSTI)

This paper describes an experimental study in which water was fed to a vertical annulus, entraining air in downward flow. The annulus was subdivided by longitudinal fins into four subchannels and was heated with an azimuthally varying heat flux. A bypass was provided to simulate flow in parallel channels. For steady liquid flow, inlet temperature, and pressure boundary conditions, the power was increased until critical heat flux was reached. Overheating characteristics were grouped according to the prevailing flow pattern. In annular flows (j{sub L} < 0.3 m/s) overheating of the whole test section occurs when steam production causes countercurrent flooding. In intermittent flows (0.3 < j{sub L} < 0.9 m/s) the overheating is confined to a portion of the hot subchannel. The mechanism is postulated to be stagnation of a large bubble. In bubble flows (0.9 m/s < j{sub L}) overheating occurs by diverting inlet flow to the bypass and again involves the whole test section. Except at the very lowest flow rates, critical heat flux occurs when the effluent liquid temperature is below saturation.

Johnston, B.S.; May, C.P.

1992-01-01T23:59:59.000Z

187

On Heating of Cluster Cooling Flows by Sound Waves  

E-Print Network [OSTI]

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.

Yutaka Fujita; Takeru Ken Suzuki

2005-08-10T23:59:59.000Z

188

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

E-Print Network [OSTI]

. 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...

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

2006-01-01T23:59:59.000Z

189

LIQUID-FLUIDIZED-BED HEAT' EXCHANGER FLOW DISTRIBUTION MODELS  

Office of Scientific and Technical Information (OSTI)

rods, and shell-side heat transfer coefficients were calculated u s i n g "Newton's Law o f Cooling": a c The horizontal tubes showed a definite angular dependence of the...

190

ENERGY CONCENTRATION FOR 2-DIMENSIONAL RADIALLY SYMMETRIC EQUIVARIANT HARMONIC MAP HEAT FLOWS  

E-Print Network [OSTI]

flows. Adapting Struwe's energy method we first establish a finite bubble tree result with a discrete, energy method, energy quanta, bubble tree, bubbling off, single bubble, intersection-comparison. AMSENERGY CONCENTRATION FOR 2-DIMENSIONAL RADIALLY SYMMETRIC EQUIVARIANT HARMONIC MAP HEAT FLOWS

Hulshof, Joost

191

ORIGINAL PAPER Flow Dynamics and Plasma Heating of Spheromaks in SSX  

E-Print Network [OSTI]

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

Brown, Michael R.

192

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

E-Print Network [OSTI]

Hydrogen Generation in Microbial Reverse-Electrodialysis Electrolysis Cells Using a Heat reverse-electrodialysis electrolysis cells (MRECs) using current derived from organic matter and salinity reverse- electrodialysis electrolysis cell (MREC), was recently shown to produce hydrogen gas from acetate

193

Improving heat capture for power generation in coal gasification plants  

E-Print Network [OSTI]

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 ...

Botros, Barbara Brenda

2011-01-01T23:59:59.000Z

194

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

E-Print Network [OSTI]

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

Loss, Daniel

195

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

E-Print Network [OSTI]

Shear flow generation by drift waves revisited P. N. Guzdar and R. G. Kleva Institute for Plasma 2000 The generation of shear flow by drift waves is an important area of investigation. In a recent paper Chen et al., Phys. Plasmas 7, 3129 2000 an elegant formalism was developed for the generation

Rubloff, Gary W.

196

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

SciTech Connect (OSTI)

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.

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

197

Numerical analysis of vapor flow in a micro heat pipe  

E-Print Network [OSTI]

be modeled as a classical blowing and suction problem, i. e. ?(00) = v(00) = o ?(I, p) = v(L0) = 0 ?(x, 0) = ?(x, H) = 0 i(x, 0) = v(x), v(x, H) = -i'(x) 0&x&I. , (2. 6) v(x, 0) = 0, v(x, H) = 0 I. , &x&(L, +L, ) i(x, 0) = -v(x), v(x, H) = v(x) (L, +L... are considerably smoother and appear more reasonable Figure 5. 6 presents the velocity vector which is under q=40W/cm2, H=0. 003m uniform heat flux linear heat flux 0 00 0 O'I 0 02 0. 03 0. 04 0. 05 0 06 x(m) Fig. 5. 2 Heat flux distribution influence...

Liu, Xiaoqin

2012-06-07T23:59:59.000Z

198

Low and high Temperature Dual Thermoelectric Generation Waste Heat Recovery  

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 Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe10IO1OP001Long-Term StorageDepartmentSystem for Light-Duty

199

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 Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat PumpRecord ofESPCof EnergyHouse11 DOEExhaust energy recovery2010Energy

200

PIV flow measurements for heat transfer characterization in two-pass square channels with smooth and 90 ribbed walls  

E-Print Network [OSTI]

PIV flow measurements for heat transfer characterization in two-pass square channels with smooth the correlation between the high- Reynolds number turbulent flow and wall heat transfer characteristics in a two number (Re) of 30,000. The PIV measurement results were compared with the heat transfer experimental data

Kihm, IconKenneth David

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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201

Statistical mechanical theory for steady-state systems. III. Heat flow in a Lennard-Jones fluid  

E-Print Network [OSTI]

Statistical mechanical theory for steady-state systems. III. Heat flow in a Lennard-Jones fluid March 2005; accepted 4 May 2005; published online 28 June 2005 A statistical mechanical theory for heat distribution for heat flow down an imposed thermal gradient is tested with simulations of a Lennard-Jones fluid

Attard, Phil

202

Two-Layer Baroclinic Eddy Heat Fluxes: Zonal Flows and Energy Balance ANDREW F. THOMPSON AND WILLIAM R. YOUNG  

E-Print Network [OSTI]

Two-Layer Baroclinic Eddy Heat Fluxes: Zonal Flows and Energy Balance ANDREW F. THOMPSON of these drag- less heat-flux parameterizations relies on the ability of to direct energy into zonal flows, California (Manuscript received 27 September 2006, in final form 13 December 2006) ABSTRACT The eddy heat

Young, William R.

203

Emissivity corrected infrared method for imaging anomalous structural heat flows  

DOE Patents [OSTI]

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.

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

204

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)

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.

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

2009-01-01T23:59:59.000Z

205

Time-delayed apparent excess heat generation in electrolysis fusion experiments  

SciTech Connect (OSTI)

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.

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

1991-04-10T23:59:59.000Z

206

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

DOE Patents [OSTI]

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.

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

2006-06-27T23:59:59.000Z

207

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

SciTech Connect (OSTI)

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.

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

208

Improved solid aerosol generator  

DOE Patents [OSTI]

An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.

Prescott, D.S.; Schober, R.K.; Beller, J.

1988-07-19T23:59:59.000Z

209

The development of a solar thermal water purification, heating, and power generation system: A case study.  

E-Print Network [OSTI]

The development of a solar thermal water purification, heating, and power generation system: A case, none of the existing concentrated solar power systems (trough, dish, and tower) that have been the potential of an invention directed to a water purification system that also recovers power from generated

Wu, Mingshen

210

Emissivity corrected infrared method for imaging anomalous structural heat flows  

DOE Patents [OSTI]

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.

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

1995-08-22T23:59:59.000Z

211

Heat Flow Database Expansion for NGDS Data Development, Collection and  

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 Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensional Subject:Ground Hawaii Clean

212

Counter flow cooling drier with integrated heat recovery  

DOE Patents [OSTI]

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.

Shivvers, Steve D. (Prole, IA)

2009-08-18T23:59:59.000Z

213

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

SciTech Connect (OSTI)

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.

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

1988-04-01T23:59:59.000Z

214

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

SciTech Connect (OSTI)

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)

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

215

Heat flow and microearthquake studies, Coso Geothermal Area, China Lake,  

Open Energy Info (EERE)

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 Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat Jump to:Photon Place:NetHealth Division |Hays,Community

216

Heat flow studies, Coso Geothermal Area, China Lake, California. Technical  

Open Energy Info (EERE)

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 Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat Jump to:Photon Place:NetHealth Division |Hays,Communityarea,

217

System and method for generating current by selective electron heating  

DOE Patents [OSTI]

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.

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

1984-01-01T23:59:59.000Z

218

Time series power flow analysis for distribution connected PV generation.  

SciTech Connect (OSTI)

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.

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

219

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

SciTech Connect (OSTI)

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.

Not Available

1992-06-01T23:59:59.000Z

220

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

SciTech Connect (OSTI)

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.

Not Available

1992-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

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

SciTech Connect (OSTI)

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.

Not Available

1992-06-01T23:59:59.000Z

222

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

SciTech Connect (OSTI)

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.

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

1982-08-01T23:59:59.000Z

223

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

SciTech Connect (OSTI)

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.

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

1992-11-01T23:59:59.000Z

224

Interpreting Velocities from Heat-Based Flow Sensors by NumericalSimulation  

SciTech Connect (OSTI)

We have carried out numerical simulations of three-dimensional non-isothermal flow around an in situ heat-based flow sensor to investigate how formation heterogeneities can affect the interpretation of ground water flow velocities from this instrument. The flow sensor operates by constant heating of a 0.75 m long, 5 cm diameter cylindrical probe, which contains 30 thermistors in contact with the formation. The temperature evolution at each thermistor can be inverted to obtain an estimate of the ground water flow velocity vector using the standard interpretive method, which assumes that the formation is homogeneous. Analysis of data from heat-based flow sensors installed in a sand aquifer at the Former Fort Ord Army Base near Monterey, California suggested an unexpected component of downward flow. The magnitudes of the vertical velocities were expected to be much less than the horizontal velocities at this site because the sensors were installed just above a clay aquitard. Numerical simulations were conducted to examine how differences in thermal conductivities may lead to spurious indications of vertical flow velocities. We found that a decrease in the thermal conductivity near the bottom of the sensor can perturb the temperature profiles along the instrument in such a manner that analyses assuming homogeneous thermal conductivity could indicate a vertical flow component even though flow is actually horizontal. This work demonstrates how modeling can be used to simulate instrument response to formation heterogeneity, and shows that caution must be used in interpreting data from such devices using overly simplistic assumptions.

Su, Grace W.; Freifeld, Barry M.; Oldenburg, Curtis M.; Jordan,Preston D.; Daley, Paul F.

2005-06-13T23:59:59.000Z

225

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

E-Print Network [OSTI]

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

Rycroft, Chris H.

226

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

227

The preliminary design of thermoelectric generation system using the fluid heat sources  

SciTech Connect (OSTI)

This paper describes the preliminary design of a thermoelectric generation system using the fluid heat sources available as the waste heat of the phosphoric acid fuel cells. The thermoelectric generator consists of many thermoelectric generation units. For estimating the output performance of the thermoelectric generator, an equilibrium thermal circuit was derived from an analytic model of a thermoelectric generation unit. Based on the equivalent thermal circuit, the output performance at thermal equilibrium was calculated by iteration. In this paper, the output performance was estimated considering the cold side pumping power. The calculation was done by assuming a heat source temperature of about 450K on the hot side, about 310 K on the cold side, and 2,000kWth as heat exchange capacity. The electric power of the generator with a size of 1.5 x 1.5 x 1.4 (h) m{sup 3} was found to be about 70 kW and its power density, about 1.5 kW/m{sup 2} excepting the pumping power on the cold water side.

Hori, Y.; Ito, T. [Central Research Inst. of Electric Power Industry, Yokosuka, Kanagawa (Japan)

1995-12-31T23:59:59.000Z

228

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

E-Print Network [OSTI]

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

Garnero, Ed

229

Flow and Heat-Transfer Apparatus, Instrumentation and Data Acquisition Method  

E-Print Network [OSTI]

friction and convective heat transfer characteristics of nanofluids. Instead of a usual closed-loop system where pumps and after-cooling units are required, the developed apparatus utilizes nitrogen pressure-driven flow to test a single batch of fluid. This reduces the complexity of the system while improving its

Kostic, Milivoje M.

230

INFLUENCE OF OHMIC HEATING ON ADVECTION-DOMINATED ACCRETION FLOWS G. S. BISNOVATYI-KOGAN  

E-Print Network [OSTI]

is advected inward, and the fraction 1 f is locally radiated. The further assumption that the energy exchange that the dissipation of turbulent energy of the flow heats the ions and that the dissipated energy is advected inward. It is suggested that the efficiency of conversion of accretion energy to radiation can be very much smaller than

231

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

E-Print Network [OSTI]

: Calibrate Seebeck Coefficient for TFTC(Thin Film Thermocouples) x y Heater (70¬įC) Water (19¬įC) #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

Taya, Minoru

232

Experimental shellside flow visualization in a shell and tube heat exchanger  

E-Print Network [OSTI]

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...

Fischer, Matthew Winslow

1998-01-01T23:59:59.000Z

233

Inferring temperature uniformity from gas composition measurements in a hydrogen combustion-heated hypersonic flow stream  

SciTech Connect (OSTI)

The application of a method for determining the temperature of an oxygen-replenished air stream heated to 2600 K by a hydrogen burner is reviewed and discussed. The purpose of the measurements is to determine the spatial uniformity of the temperature in the core flow of a ramjet test facility. The technique involves sampling the product gases at the exit of the test section nozzle to infer the makeup of the reactant gases entering the burner. Knowing also the temperature of the inlet gases and assuming the flow is at chemical equilibrium, the adiabatic flame temperature is determined using an industry accepted chemical equilibrium computer code. Local temperature depressions are estimated from heat loss calculations. A description of the method, hardware and procedures is presented, along with local heat loss estimates and uncertainty assessments. The uncertainty of the method is estimated at {+-}31 K, and the spatial uniformity was measured within {+-}35 K.

Olstad, S.J. [Phoenix Solutions Co., Minneapolis, MN (United States)

1995-08-01T23:59:59.000Z

234

Comparison of strongly heat-driven flow codes for unsaturated media  

SciTech Connect (OSTI)

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.

Updegraff, C.D.

1989-08-01T23:59:59.000Z

235

Simulated Surface-Induced Thrombin Generation in a Flow Field  

E-Print Network [OSTI]

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 ...

Jordan, S.W.

236

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

E-Print Network [OSTI]

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

Camci, Cengiz

237

Study of junction flows in louvered fin round tube heat exchangers using the dye injection technique  

SciTech Connect (OSTI)

Detailed studies of junction flows in heat exchangers with an interrupted fin design are rare. However, understanding these flow structures is important for design and optimization purposes, because the thermal hydraulic performance of heat exchangers is strongly related to the flow behaviour. In this study flow visualization experiments were performed in six scaled-up models of a louvered fin round tube heat exchanger. The models have three tube rows in a staggered layout and differ only in their fin spacing and louver angle. A water tunnel was designed and built and the flow visualizations were carried out using dye injection. At low Reynolds numbers the streakline follows the tube contours, while at higher Reynolds numbers a horseshoe vortex is developed ahead of the tubes. The two resulting streamwise vortex legs are destroyed by the downstream louvers (i.e. downstream the turnaround louver), especially at higher Reynolds numbers, smaller fin pitches and larger louver angles. Increasing the fin spacing results in a larger and stronger horseshoe vortex. This illustrates that a reduction of the fin spacing results in a dissipation of vortical motion by mechanical blockage and skin friction. Furthermore it was observed that the vortex strength and number of vortices in the second tube row is larger than in the first tube row. This is due to the thicker boundary layer in the second tube row, and the flow deflection, which is typical for louvered fin heat exchangers. Visualizations at the tube-louver junction showed that in the transition part between the angled louver and the flat landing a vortex is present underneath the louver surface which propagates towards the angled louver. (author)

Huisseune, H.; Willockx, A.; De Paepe, M. [Department of Flow, Heat and Combustion Mechanics, Ghent University, Sint-Pietersnieuwstraat 41, 9000 Gent (Belgium); T'Joen, C. [Department of Flow, Heat and Combustion Mechanics, Ghent University, Sint-Pietersnieuwstraat 41, 9000 Gent (Belgium); Department Radiation, Radionuclides and Reactors, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); De Jaeger, P. [Department of Flow, Heat and Combustion Mechanics, Ghent University, Sint-Pietersnieuwstraat 41, 9000 Gent (Belgium); NV Bekaert SA, Bekaertstraat 2, 8550 Zwevegem (Belgium)

2010-11-15T23:59:59.000Z

238

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

E-Print Network [OSTI]

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

Kasagi, Nobuhide

239

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

SciTech Connect (OSTI)

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.

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

2012-01-01T23:59:59.000Z

240

EUROTHERM Seminar 74 Proceedings Heat transfer in unsteady and transitional flows March 23-26, 2003 Eindhoven (The Netherlands)  

E-Print Network [OSTI]

EUROTHERM Seminar 74 Proceedings Heat transfer in unsteady and transitional flows March 23-26, 2003 to be governed by heat transfer and time microscales of turbulence through the inner sublayer. Physical interpreta- tions are given to relate the observed heat transfer correlation and these turbulence transition

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

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

242

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

SciTech Connect (OSTI)

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.

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

2010-10-21T23:59:59.000Z

243

The influence of convective heat transfer on flow stability in rotating disk chemical vapor deposition reactors  

SciTech Connect (OSTI)

Flow and heat transfer of NH{sub 3} and He were studied in a rotating disk system with applications to chemical vapor deposition reactors. Flow field and disk heat flux were obtained over a range of operating conditions. Comparisons of disk convective heat transfer were made to infinite rotating disk results to appraise uniformity of transport to the disk. Important operating variables include disk spin rate, disk and enclosure temperatures, flow rate, composition, pressure, and gas mixture temperature at the reactor inlet. These variables were studied over ranges of the spin Reynolds number, Re{omega}; disk mixed convection parameter, MCP{sub w}; and wall mixed convection parameter, MCP{sub w}. Results obtained for NH{sub 3} show that increasing Re{omega} from 314.5 to 3145 increases the uniformity of rotating disk heat flux and results in thinner thermal boundary layers at the disk surface. At Re{omega}=314.5, increasing MCP{sub d} to 15 leads to significant departure from the infinite disk result with nonuniform disk heat fluxes and recirculating flow patterns; flow becomes increasingly complex at larger values of MCP{sub d}. At Re{omega} of 3145, results are closer to the infinite disk for MCP{sub d} up to 15. For large negative (hot walls) and positive (cold walls) values of MCP{sub w}, flow recirculates and there is significant deviation from the infinite disk result; nonuniformities occur at both values of Re{omega}. The influence of MCP{sub w} on flow stability is increased at larger MCP{sub d} and lower Re{omega}. To determine the influence of viscosity and thermal conductivity variation with temperature, calculations were made with He and NH{sub 3}; He transport property variation is low relative to NH{sub 3}. Results show that the flow of NH{sub 3} is less stable than that of He as MCP{sub d} is increased for MCP{sub w}=0 and Re{omega}=314.5. 16 refs., 15 figs., 1 tab.

Winters, W.S.; Evans, G.H. [Sandia National Labs., Livermore, CA (United States); Grief, R. [Univ. of California, Berkeley, CA (United States). Mechanical Engineering Dept.

1997-06-01T23:59:59.000Z

244

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

SciTech Connect (OSTI)

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.

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

2004-11-30T23:59:59.000Z

245

A turbulence model for buoyant flows based on vorticity generation.  

SciTech Connect (OSTI)

A turbulence model for buoyant flows has been developed in the context of a k-{var_epsilon} turbulence modeling approach. A production term is added to the turbulent kinetic energy equation based on dimensional reasoning using an appropriate time scale for buoyancy-induced turbulence taken from the vorticity conservation equation. The resulting turbulence model is calibrated against far field helium-air spread rate data, and validated with near source, strongly buoyant helium plume data sets. This model is more numerically stable and gives better predictions over a much broader range of mesh densities than the standard k-{var_epsilon} model for these strongly buoyant flows.

Domino, Stefan Paul; Nicolette, Vernon F.; O'Hern, Timothy John; Tieszen, Sheldon R.; Black, Amalia Rebecca

2005-10-01T23:59:59.000Z

246

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

SciTech Connect (OSTI)

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}

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

1995-01-20T23:59:59.000Z

247

Turbulent heat transfer in parallel flow boundary layers with streamwise step changes in surface conditions  

SciTech Connect (OSTI)

This paper examines the convective heat/mass transfer behavior of a turbulent boundary layer with parallel streamlines. The most notable example of such flow is an atmospheric boundary layer with a steady mean wind in the absence of topography. The classic, two-dimensional problem involves the surface boundary condition of a finite-length step change in temperature/concentration in the streamwise direction of an atmospheric flow. In the literature on geophysical evapotranspiration, this problem is known as Sutton's problem (cf. Sutton, 1934, and Brutsaert, 1984). This flow situation is equally applicable to heat/mass transfer in solar ponds, ground solar collectors, and heated roadways, as examples. The present note revisits the Sutton problem, with the can Driest eddy diffusivity model, and expands the types of boundary conditions that are examined to include surface changes in temperature/concentration and fluxes. The parallel streamline condition allows for Graetz-type solutions, with boundary conditions at the surface and in the far flow field. The predicted results are presented as a series of power law correlations of the relevant nondimensional parameters.

Lindberg, W.R.; Lee, R.C.; Smathers, L.B. (Univ. of Wyoming, Laramie (United States))

1989-11-01T23:59:59.000Z

248

Micro-canonical thermodynamics: Why does heat flow from hot to cold  

E-Print Network [OSTI]

We consider two weakly coupled Hamiltonian dynamical systems in the micro-canonical ensemble. We describe a stochastic model for the energy-transfer between two systems initially at different micro-canonical temperatures. Fluctuations in energy observables are shown to be the underlying source of heat-transfer (dissipation). As a result, on average, heat flows from hot to cold. Like in Evans et al. (Phys.\\ Rev.\\ Lett.) [71], 2401 (1993), we obtain a universal law of violation of the 2nd law of thermodynamics.

Rugh, Hans Henrik

2012-01-01T23:59:59.000Z

249

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

SciTech Connect (OSTI)

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.

Sharma, Chandan; Raustad, Richard

2013-06-01T23:59:59.000Z

250

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

SciTech Connect (OSTI)

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.

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

1990-01-01T23:59:59.000Z

251

Internal flow patterns on heat transfer characteristics of a closed-loop oscillating heat-pipe with check valves using ethanol and a silver nano-ethanol mixture  

SciTech Connect (OSTI)

The aim of this research was to investigate the internal flow patterns and heat transfer characteristics of a closed-loop oscillating heat-pipe with check valves (CLOHP/CV). The ratio of number of check valves to meandering turns was 0.2. Ethanol and a silver nano-ethanol mixture were used as working fluids with a filling ratio of 50% by total volume of tube. The CLOHP/CV was made of a glass tube with an inside diameter of 2.4 mm. The evaporator section was 50 mm and 100 mm in length and there were 10 meandering turns. An inclination angle of 90 from horizontal axis was established. The evaporator section was heated by an electric heater and the condenser section was cooled by distilled water. Temperature at the evaporator section was controlled at 85 C, 105 C and 125 C. The inlet and outlet temperatures were measured. A digital camera and video camera were used to observe the flow patterns at the evaporator. The silver nano-ethanol mixture gave higher heat flux than ethanol. When the temperature at the evaporator section was increased from 85 C to 105 C and 125 C. It was found that, the flow patterns occurred as annular flow + slug flow, slug flow + bubble flow and dispersed bubble flow + bubble flow respectively. The main regime of each flow pattern can be determined from the flow pattern map ethanol and a silver nano-ethanol mixture. Each of the two working fluids gave corresponding flow patterns. (author)

Bhuwakietkumjohn, N.; Rittidech, S. [Heat Pipe and Thermal Tools Design Research Laboratory (HTDR), Faculty of Engineering, Mahasarakham University, Mahasarakham 44150 (Thailand)

2010-11-15T23:59:59.000Z

252

Heat extracted from the long term flow test in the Fenton Hill HDR reservoir  

SciTech Connect (OSTI)

A long-term flow test was carried out in the Fenton Hill HDR Phase-2 reservoir for 14 months during 1992-1993 to examine the potential for supplying thermal energy at a sustained rate as a commercial demonstration of HDR technology. The test was accomplished in several segments with changes in mean flowrate due to pumping conditions. Re-test estimates of the extractable heat content above a minimum useful temperature were based on physical evidence of the size of the Fenton Hill reservoir. A numerical model was used to estimate the extent of heat extracted during the individual flow segments from the database of measured production data during the test. For a reservoir volume of 6.5x10{sup 6}m{sup 3}, the total heat content above a minimum temperature of 150{degree} C was 1.5x10{sup 15}J. For the total test period at the three sustained mean flowrates, the integrated heat extracted was 0.088x10{sup 15}J, with no discernable temperature decline of the produced fluid. The fraction of energy extracted above the abandonment temperature was 5.9%. On the basis of a constant thermal energy extraction rate, the lifetime of the reservoir (without reservoir growth) to the abandonment temperature would be 13.3 years, in good agreement with the pre-test estimate of 15.0 years for the given reservoir volume.

Kruger, Paul; Robinson, Bruce

1994-01-20T23:59:59.000Z

253

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

SciTech Connect (OSTI)

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.

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

1993-07-01T23:59:59.000Z

254

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

SciTech Connect (OSTI)

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.

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

2009-01-11T23:59:59.000Z

255

Evaluation Metrics for Intermediate Heat Exchangers for Next Generation Nuclear Reactors  

SciTech Connect (OSTI)

The Department of Energy (DOE) is working with industry to develop a next generation, high-temperature gas-cooled reactor (HTGR) as a part of the effort to supply the United States with abundant, clean, and secure energy as initiated by the Energy Policy Act of 2005 (EPAct; Public Law 109-58,2005). The NGNP Project, led by the Idaho National Laboratory (INL), will demonstrate the ability of the HTGR to generate hydrogen, electricity, and/or high-quality process heat for a wide range of industrial applications.

Piyush Sabharwall; Eung Soo Kim; Nolan Anderson

2011-06-01T23:59:59.000Z

256

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

SciTech Connect (OSTI)

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.

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

2014-06-01T23:59:59.000Z

257

Investigation And Evaluation Of The Systemwide Economic Benefits Of Combined Heat And Power Generation In The New York State Energy Market.  

E-Print Network [OSTI]

??Combined Heat and Power (CHP) is the production of electricity and the simultaneous utilization of the heat produced by the generator prime mover. The energyÖ (more)

Baquero, Ricardo

2008-01-01T23:59:59.000Z

258

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

DOE Patents [OSTI]

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)

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

1980-05-27T23:59:59.000Z

259

Assessment of district heating and cooling supply from Goudey Generating Station  

SciTech Connect (OSTI)

This paper addresses the feasibility analysis of retrofitting the New York State Electric and Gas (NYSEG) Goudey Generating Station for district heating and cooling supply to the SUNY-Binghamton Campus. The project involved detailed analysis of the power plant retrofit, dispatch analysis of the retrofitted Goudey Station in the New York Power Pool, environmental and permitting assessment, retrofit analysis of the SUNY campus to low temperature hot water and economic analysis.

McIntire, M.E.; Hall, D.; Beal, D.J. [New York State Electric & Gas Corporation, Binghamton, NY (United States)] [and others

1995-06-01T23:59:59.000Z

260

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

SciTech Connect (OSTI)

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.

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

1999-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

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

SciTech Connect (OSTI)

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

Barnette, D.W.

1998-02-01T23:59:59.000Z

262

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

SciTech Connect (OSTI)

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

Raustad, Richard; Nigusse, Bereket; Domitrovic, Ron

2013-09-30T23:59:59.000Z

263

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

SciTech Connect (OSTI)

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.

N. A. Anderson; P. Sabharwall

2014-01-01T23:59:59.000Z

264

Cross-Roll Flow Forming of ODS Alloy Heat Exchanger Tubes for Hoop Creep Enhancement  

SciTech Connect (OSTI)

Mechanically alloyed oxide dispersion strengthened (ODS) Fe-Cr-Al alloy thin walled tubes and sheets, produced via powder processing and consolidation methodologies, are promising materials for eventual use at temperatures up to 1200 C in the power generation industry, far above the temperature capabilities of conventional alloys. Target end-uses range from gas turbine combustor liners to high aspect ratio (L/D) heat exchanger tubes. Grain boundary creep processes at service temperatures, particularly those acting in the hoop direction, are the dominant failure mechanisms for such components. The processed microstructure of ODS alloys consists of high aspect ratio grains aligned parallel to the tube axis, a result of dominant axial metal flow which aligns the dispersoid particles and other impurities in the longitudinal direction. The dispersion distribution is unaltered on a micro scale by recrystallization thermal treatments, but the high aspect ratio grain shape typically obtained limits transverse grain spacing and consequently the hoop creep response. Improving hoop creep in ODS-alloy components will require understanding and manipulating the factors that control the recrystallization behavior, and represents a critical materials design and development challenge that must be overcome in order to fully exploit the potential of ODS alloys. The objectives of this program are to (1) increase creep-strength at temperature in ODS-alloy tube and liner components by 100% via, (2) preferential cross-roll flow forming and grain/particle fibering in the critical hoop direction. The research program outlined here is iterative in nature and is intended to systematically (1) examine and identify post-extrusion forming methodologies to create hoop strengthened tubes, which will be (2) evaluated at ''in-service'' loads at service temperatures and environments. This research program is being conducted in collaboration with the DOE's Oak Ridge National Laboratory and the vested industrial partner Special Metals Corporation. In this ninth quarter of performance, program activities are continued for Tasks 2, 3 and 4 and are reported herein. Two sets of MA956 tube material samples rotary crossrolled at rolling angles of {beta} = 2{sup o} and 8{sup o} are processed in Task 3 and available for mechanical property testing in the remainder of this project. These samples are at various stages of creep testing and evaluation in Task 4. The creep rigs are being upgraded to handle long term testing at 1000 C and above. Reduced test times at accelerated temperatures will allow for additional testes to be conducted resulting in overall robust creep data statistics. The creep performance enhancement in cross-rolled MA956 material samples versus the base creep property is elucidated. Additional creep enhancements are derived when flow formed tubes are flattened at 900 C and recrystallized. The Larsen-Miller parameter for the improvised thermo-mechanical processing now approaches 52. At least 2-3 orders of magnitude of improvement in creep rates/day are demonstrated for the cross-rolled samples versus the base reference tests.

Bimal K. Kad

2006-04-10T23:59:59.000Z

265

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

SciTech Connect (OSTI)

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.

Matei, M.

1998-07-01T23:59:59.000Z

266

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

SciTech Connect (OSTI)

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.

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

2010-09-01T23:59:59.000Z

267

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

E-Print Network [OSTI]

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...

Greendyke, Robert Brian

2012-06-07T23:59:59.000Z

268

Numerical Evaluation of Flow and Heat Transfer in Plate-Pin Fin Heat Sinks with Various Pin Cross-Sections  

E-Print Network [OSTI]

in Table 3. The grid systems for all heat sink models areregion. The grid system for one of the heat sinks is shown

Zhou, Feng; Catton, Ivan

2011-01-01T23:59:59.000Z

269

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

SciTech Connect (OSTI)

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.

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

270

Micro-canonical thermodynamics: Why does heat flow from hot to cold  

E-Print Network [OSTI]

We show how to use a central limit approximation for additive co-cycles to describe non-equilibrium and far from equilibrium thermodynamic behavior. We consider first two weakly coupled Hamiltonian dynamical systems initially at different micro-canonical temperatures. We describe a stochastic model where the energy-transfer between the two systems is considered as a random variable satisfying a central limit approximation. We show that fluctuations in energy observables are linearly related to the heat-transfer (dissipation). As a result, on average, heat flows from hot to cold. We also consider the far from equilibrium situation of a non-Hamiltonian thermostatted system as in Evans et al. {\\em Phys.\\ Rev.\\ Lett.} {\\bf 71}, 2401 (1993). Applying the same central limit approximation we re-derive their relation for the violation of the 2nd law of thermodynamics. We note that time-reversal symmetry is not used in our derivation.

Hans Henrik Rugh

2012-04-10T23:59:59.000Z

271

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

E-Print Network [OSTI]

. 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

Marques, Francisco

272

Shear flow generation from the interaction of neoclassical and drift wave transport processes  

SciTech Connect (OSTI)

Self-consistent shear flow generation from the interaction of neoclassical and drift wave turbulence effects is investigated. The neoclassical poloidal flow damping is shown to compete with the flow generation driven by the divergence of the Reynolds stress. When there is no external driving force except for the free energy released from toroidal shear flow, the turbulent fluctuations occur as a transient pulse which takes the system along an equilibrium path to a relaxed state. External torques, such as parallel neutral beam injection, are needed to maintain significant fluctuation levels. For a system driven by a fixed ion temperature gradient, although linearly the poloidal shear flow generated substantially reduces the growth rate, the simulation results show that a sequence of nonlinear pulses occurs that eventually build the fluctuations up to a level that is not significantly affected by the poloidal flow. In this new, highly nonlinear state the transport is intermittent occurring through a sequence of pulses of duration 100 L{sub n}/c{sub s} for typical parameters.

Su, X.N.; Yushmanov, P.N.; Dong, J.Q.; Horton, W.

1993-10-01T23:59:59.000Z

273

On the calculation of flow and heat transfer characteristics for CANDU-type 19-rod fuel bundles  

SciTech Connect (OSTI)

A numerical study is reported of flow and heat transfer in a CANDU-type 19 rod fuel bundle. The flow domain of interest includes combinations of trangular, square, and peripheral subchannels. The basic equations of momentum and energy are solved with the standard k--epsilon model of turbulence. Isotropic turbulent viscosity is assumed and no secondary flow is considered for this steady-state, fully developed flow. Detailed velocity and temperature distributions with wall shear stress and Nusselt number distributions are obtained for turbulent flow of Re = 4.35 x 10/sup 4/, 10/sup 5/, 2 x 10/sup 5/, and for laminar flow of Re--2400. Friction factor and heat transfer ceofficients of various subchannels inside the full bundle are compared with those of infinite rod arrays of triangular or square arrangements. The calculated velocity contours of peripheral subchannel agreed reasonably with measured data.

Yuh-Shan Yueh; Ching-Chang Chieng

1987-08-01T23:59:59.000Z

274

On the calculation of flow and heat transfer characteristics for CANDU-type 19-rod fuel bundles  

SciTech Connect (OSTI)

A numerical study is reported of flow and heat transfer in a CANDU-type 19 rod fuel bundle. The flow domain of interest includes combinations of triangular, square, and peripheral subchannels. The basic equations of momentum and energy are solved with the standard k-{epsilon} model of turbulence. Isotropic turbulent viscosity is assumed and no secondary flow is considered for this steady-state, fully developed flow. Detailed velocity and temperature distributions with wall shear stress and Nusselt number distributions are obtained for turbulent flow of Re = 4.35 {times} 10{sup 4}, 10{sup 5}, 2 {times} 10{sup 5}, and for laminar flow of Re {approximately} 2,400. Friction factor and heat transfer coefficients of various subchannels inside the full bundle are compared with those of infinite rod arrays of triangular or square arrangements. The calculated velocity contours of peripheral subchannel agreed reasonably with measured data.

Yueh, Yuhshan; Chieng, Chingchang (National Tsing Hua Univ., Hsinchu (Taiwan))

1987-08-01T23:59:59.000Z

275

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

E-Print Network [OSTI]

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.

William R. Gorman; James D. Brownridge

2008-09-04T23:59:59.000Z

276

On numerical simulation of flow, heat transfer and combustion processes in tangentially-fired furnace  

SciTech Connect (OSTI)

In this work, an Eulerian/Lagrangian approach has been employed to investigate numerically flow characteristics, heat transfer and combustion processes inside corner-fired power plant boiler furnace. To avoid pseudo-diffusion that is significant in modeling tangentially-fired furnaces, some attempts have been made at improving the finite-difference scheme. Comparisons have been made between standard {kappa}-{epsilon} model and RNG {kappa}-{epsilon} model. Some new developments on turbulent diffusion of particles are taken into account in an attempt to improve computational accuracy. Finally, temperature deviation is studied numerically so as to gain deeper insight into tangentially fired furnace.

Sun, P.; Fan, J.; Cen, K.

1999-07-01T23:59:59.000Z

277

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

SciTech Connect (OSTI)

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.

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

1986-01-21T23:59:59.000Z

278

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

SciTech Connect (OSTI)

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.

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

279

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.

280

Transient Heat and Material Flow Modeling of Friction Stir Processing of Magnesium Alloy using Threaded Tool  

SciTech Connect (OSTI)

A three-dimensional transient computational fluid dynamics (CFD) model was developed to investigate the material flow and heat transfer during friction stir processing (FSP) in an AZ31B magnesium alloy. The material was assumed to be a non-Newtonian viscoplastic fluid, and the Zener-Hollomon parameter was used to describe the dependence of material viscosity on temperature and strain rate. The material constants used in the constitutive equation were determined experimentally from compression tests of the AZ31B Mg alloy under a wide range of strain rates and temperatures. A dynamic mesh method, combining both Lagrangian and Eulerian formulations, was used to capture the material flow induced by the movement of the threaded tool pin. Massless inert particles were embedded in the simulation domain to track the detailed history of material flow. The actual FSP was also carried out on a wrought Mg plate where temperature profiles were recorded by embedding thermocouples. The predicted transient temperature history was found to be consistent with that measured during FSP. Finally, the influence of the thread on the simulated results of thermal history and material flow was studied by comparing two models: one with threaded pin and the other with smooth pin surface.

Yu, Zhenzhen [ORNL; Zhang, Wei [ORNL; Choo, Hahn [ORNL; Feng, Zhili [ORNL

2012-01-01T23:59:59.000Z

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281

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

SciTech Connect (OSTI)

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.

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

282

On the dynamical Rayleigh-Taylor instability in compressible viscous flows without heat conductivity  

E-Print Network [OSTI]

We investigate the instability of a smooth Rayleigh-Taylor steady-state solution to compressible viscous flows without heat conductivity in the presence of a uniform gravitational field in a bounded domain $\\Omega\\subset{\\mathbb R}^3$ with smooth boundary $\\partial\\Omega$. We show that the steady-state is linearly unstable by constructing a suitable energy functional and exploiting arguments of the modified variational method. Then, based on the constructed linearly unstable solutions and a local well-posedness result of classical solutions to the original nonlinear problem, we further reconstruct the initial data of linearly unstable solutions to be the one of the original nonlinear problem and establish an appropriate energy estimate of Gronwall-type. With the help of the established energy estimate, we show that the steady-state is nonlinearly unstable in the sense of Hadamard by a careful bootstrap argument. As a byproduct of our analysis, we find that the compressibility has no stabilizing effect in the linearized problem for compressible viscous flows without heat conductivity.

Fei Jiang; Song Jiang

2014-03-20T23:59:59.000Z

283

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

E-Print Network [OSTI]

of virtual impedance parameters and (ii) higher accuracy in reactive power flow calculation. The improved With larger portion of growing electricity demand which is being fed through distributed generation (DG, in order to decouple real and reactive power, to increase the stability margin and also to improve

Chaudhary, Sanjay

284

Zonal flow and field generation by finite beta drift waves and kinetic drift-Alfven waves  

E-Print Network [OSTI]

Zonal flow and field generation by finite beta drift waves and kinetic drift-Alfve¬īn waves P. N magnetic fields by finite beta drift waves and kinetic drift-Alfve¬īn waves is presented. The analysis by electrostatic drift waves to finite beta drift waves and kinetic drift-Alfve¬īn waves. The drift wave driven

Rubloff, Gary W.

285

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

E-Print Network [OSTI]

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

Liberzon, Daniel

286

The case for endurance testing of sodium-heated steam generators  

SciTech Connect (OSTI)

It is generally believed that a nuclear power comeback before the end of the century will be through the vehicle of the light water reactor (LWR). The newer designs, with their important technical and economic advances, should attract wide interest and result in commercial success for the manufacturers and their utility customers. To develop the liquid-metal fast breeder reactor (LMFBR), approximately $30 billion has been spent worldwide, a third of which has been spent in the US. As a result of this considerable investment, most of the technical obstacles to deployment of the LMFBR have been removed with a few exceptions, one of which is the long-term performance of sodium-heated steam generators. Of the difficulties that have beset the current vintage of nuclear power plants, the performance of steam generators in pressurized water reactors (PWRs) was the most egregious. There was very little development testing and no model testing of PWR steam generators. Development occurred in the plants themselves resulting in many outages and more than $5 billion in lost revenue and replacement power costs. As a result, the electric utility industry is certain to exercise caution regarding acquisition of the LMFBR and will demand strong objective evidence of steam generator reliability. Only long-term endurance testing of prototypic models under prototypic conditions will satisfy this demand.

Onesto, A.T.; Zweig, H.R.; Gibbs, D.C. (Energy Technology Engineering Center, Canoga Park, CA (United States))

1992-01-01T23:59:59.000Z

287

Development of thermoelectric power generation system utilizing heat of combustible solid waste  

SciTech Connect (OSTI)

The paper presents the development of thermoelectric power generation system utilizing heat of municipal solid waste. The systematic classification and design guideline are proposed in consideration of the characteristics of solid waste processing system. The conceptual design of thermoelectric power generation system is carried out for a typical middle scale incinerator system (200 ton/day) by the local model. Totally the recovered electricity is 926.5 kWe by 445 units (569,600 couples). In order to achieve detailed design, one dimensional steady state model taking account of temperature dependency of the heat transfer performance and thermoelectric properties is developed. Moreover, small scale on-site experiment on 60 W class module installed in the real incinerator is carried out to extract various levels of technological problems. In parallel with the system development, high temperature thermoelectric elements such as Mn-Si and so on are developed aiming the optimization of ternary compound and high performance due to controlled fine-grain boundary effect. The manganese silicide made by shrinking-rate controlled sintering method performs 5 ({mu}W/cm K{cflx 2}) in power factor at 800 K. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

Kajikawa, T.; Ito, M.; Katsube, I. [Shonan Institute of Technology, Fujisawa, Kanagawa, 251 (Japan); Shibuya, E. [NKK Corporation, Yokohama, Kanagawa, 230 (Japan)

1994-08-10T23:59:59.000Z

288

Air bottoming cycle: Use of gas turbine waste heat for power generation  

SciTech Connect (OSTI)

This paper presents a thermodynamic analysis of the Air Bottoming Cycle (ABC) as well as the results of a feasibility study for using the Air Bottoming Cycle for gas turbine waste heat recovery/power generation on oil/gas platforms in the North Sea. The basis for the feasibility study was to utilize the exhaust gas heat from an LM2500PE gas turbine. Installation of the ABC on both a new and an existing platform have been considered. A design reference case is presented, and the recommended ABC is a two-shaft engine with two compressor intercoolers. The compression pressure ratio was found optimal at 8:1. The combined gas turbine and ABC shaft efficiency wa/s calculated to 46.6 percent. The LM2500PE gas turbine contributes with 36.1 percent while the ABC adds 10.5 percent points to the gas turbine efficiency. The ABC shaft power output is 6.6 MW when utilizing the waste heat of an LM2500PE gas turbine. A preliminary thermal and hydraulic design of the ABC main components (compressor, turbine, intercoolers, and recuperator) was carried out. The recuperator is the largest and heaviest component (45 tons). A weight and cost breakdown of the ABC is presented. The total weight of the ABC package was calculated to 154 metric tons, and the ABC package cost to 9.4 million US$. An economical examination for three different cases was carried out. The results show that the ABC alternative (LM2500PE + ABC) is economical, with a rather good margin, compared to the other alternatives. The conclusion is that the Air Bottoming Cycle is an economical alternative for power generation on both new platforms and on existing platforms with demand for more power.

Bolland, O.; Foerde, M. [Norwegian Univ. of Science and Technology, Trondheim (Norway). Div. of Thermal Energy and Hydropower; Haande, B. [Oil Engineering Consultants, Sandvika (Norway)

1996-04-01T23:59:59.000Z

289

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

SciTech Connect (OSTI)

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

Anne Trehu; Peter Kannberg

2011-06-30T23:59:59.000Z

290

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

SciTech Connect (OSTI)

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

Trehu, Anne; Kannberg, Peter

2011-06-30T23:59:59.000Z

291

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

E-Print Network [OSTI]

Forced Convection Heat Transfer in Curved RectangularInfluence of Curvature on Heat Transfer to IncompressibleT. , "Forced Convective Heat Transfer in a Curved Channel

Yee, G.

2010-01-01T23:59:59.000Z

292

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

E-Print Network [OSTI]

as other types of air source heat pumps, VRF systems needconventional packaged air source heat pumps. Typical GSHPis basically an air source heat pump), especially when the

Hong, Tainzhen

2010-01-01T23:59:59.000Z

293

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

SciTech Connect (OSTI)

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

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

2005-06-03T23:59:59.000Z

294

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

SciTech Connect (OSTI)

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.

Belle R. Upadhyaya; J. Wesley Hines

2004-09-27T23:59:59.000Z

295

Entropy Generation In The Viscous Layer Of A Turbulent Channel Flow  

SciTech Connect (OSTI)

The local (pointwise) entropy generation rate per unit volume S''' is a key to improving many energy processes and applications. Entropy generation due to friction occurs from viscous dissipation of mean-flow kinetic energy (called "direct dissipation") and dissipation of turbulent kinetic energy into thermal energy ("indirect" or turbulent dissipation). The objective of the present study is to compare two approaches for the prediction of S''' for the viscous layer in near asymptotic (high Reynolds number) turbulent flows. By employing available direct numerical simulations (DNS) it was found that about two-thirds of the entropy generation occurs in this layer. A popular approximate approach does not agree with the result from the more exact evaluation of S''' but its integral falls within about four per cent at the edge of the viscous layer.

D. M. McEligot; E. J. Walsh; E. Laurien; James R. Wolf

2006-09-01T23:59:59.000Z

296

Countercurrent flow limited (CCFL) heat flux in the high flux isotope reactor (HFIR) fuel element  

SciTech Connect (OSTI)

The countercurrent flow (CCF) performance in the fuel element region of the HFIR is examined experimentally and theoretically. The fuel element consists of two concentric annuli filled with aluminum clad fuel plates of 1.27 mm thickness separated by 1.27 mm flow channels. The plates are curved as they go radially outward to accomplish constant flow channel width and constant metal-to-coolant ratio. A full-scale HFIR fuel element mock-up is studied in an adiabatic air-water CCF experiment. A review of CCF models for narrow channels is presented along with the treatment of CCFs in system of parallel channels. The experimental results are related to the existing models and a mechanistic model for the annular'' CCF in a narrow channel is developed that captures the data trends well. The results of the experiment are used to calculate the CCFL heat flux of the HFIR fuel assembly. It was determined that the HFIR fuel assembly can reject 0.62 Mw of thermal power in the CCFL situation. 31 refs., 17 figs.

Ruggles, A.E.

1990-10-12T23:59:59.000Z

297

GENERATION, TRANSPORT AND DEPOSITION OF TUNGSTEN-OXIDE AEROSOLS AT 1000 C IN FLOWING AIR-STEAM MIXTURES.  

SciTech Connect (OSTI)

Experiments were conducted to measure the rates of oxidation and vaporization of pure tungsten rods in flowing air, steam and air-steam mixtures in laminar flow. Also measured were the downstream transport of tungsten-oxide condensation aerosols and their region of deposition, including plateout in the superheated flow tube, rainout in the condenser and ambient discharge which was collected on an array of sub-micron aerosol filters. The nominal conditions of the tests, with the exception of the first two tests, were tungsten temperatures of 1000 C, gas mixture temperatures of 200 C and wall temperatures of 150 C to 200 C. It was observed that the tungsten oxidation rates were greatest in all air and least in all steam, generally decreasing non-linearly with increasing steam mole fraction. The tungsten oxidation rates in all air were more than five times greater than the tungsten oxidation rates in all steam. The tungsten vaporization rate was zero in all air and increased with increasing steam mole fraction. The vaporization rate became maximum at a steam mole fraction of 0.85 and decreased thereafter as the steam mole fraction was increased to unity. The tungsten-oxide was transported downstream as condensation aerosols, initially flowing upwards from the tungsten rod through an 18-inch long, one-inch diameter quartz tube, around a 3.5-inch radius, 90{sup o} bend and laterally through a 24-inch horizontal run. The entire length of the quartz glass flow path was heated by electrical resistance clamshell heaters whose temperatures were individually controlled and measured. The tungsten-oxide plateout in the quartz tube was collected, nearly all of which was deposited at the end of the heated zone near the entrance to the condenser which was cold. The tungsten-oxide which rained out in the condenser as the steam condensed was collected with the condensate and weighed after being dried. The aerosol smoke which escaped the condenser was collected on the sub-micron filter assemblies. There was no aerosol generation for the case of all air, so the plateout, condensate and smoke were all zero. For the case of all steam, there was very little plateout in the superheated regions (several percent) and the rest of the aerosol was collected in the condensate from the condenser. There was no smoke discharge into the filters. For the experiments with intermediate air-steam fractions, there was some aerosol plateout, considerable aerosol in the condensate and aerosol smoke discharged from the condenser with the escaping air.

GREENE,G.A.; FINFROCK,C.C.

2001-10-01T23:59:59.000Z

298

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]

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

Virginia Tech

299

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

E-Print Network [OSTI]

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).

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

2009-05-07T23:59:59.000Z

300

Quality Assurance Plan for Heat Source/Radioisotope Thermoelectric Generator Programs  

SciTech Connect (OSTI)

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.

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

1995-03-16T23:59:59.000Z

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

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

SciTech Connect (OSTI)

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.

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

1991-09-01T23:59:59.000Z

302

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

SciTech Connect (OSTI)

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.

Babione, R.A.

1988-04-01T23:59:59.000Z

303

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

SciTech Connect (OSTI)

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.

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

2013-02-01T23:59:59.000Z

304

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]

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 ...

Sugrue, Rosemary M

2012-01-01T23:59:59.000Z

305

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)

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)

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

306

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)

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.

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

2013-02-01T23:59:59.000Z

307

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]

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

1994-01-01T23:59:59.000Z

308

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

SciTech Connect (OSTI)

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.

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

1990-04-01T23:59:59.000Z

309

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

SciTech Connect (OSTI)

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.

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

310

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

DOE Patents [OSTI]

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.

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

1998-01-01T23:59:59.000Z

311

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

SciTech Connect (OSTI)

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.

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

312

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

SciTech Connect (OSTI)

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.

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

2008-12-01T23:59:59.000Z

313

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

E-Print Network [OSTI]

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

Hong, Tainzhen

2010-01-01T23:59:59.000Z

314

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

E-Print Network [OSTI]

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

Hong, Tainzhen

2010-01-01T23:59:59.000Z

315

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

E-Print Network [OSTI]

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 ...

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

2009-01-01T23:59:59.000Z

316

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

E-Print Network [OSTI]

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

Aguilar, Guillermo

317

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

E-Print Network [OSTI]

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

Eagar, Thomas W.

318

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)

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.

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

2011-01-19T23:59:59.000Z

319

Geothermal Resource/Reservoir Investigations Based on Heat Flow and Thermal Gradient Data for the United States  

SciTech Connect (OSTI)

Several activities related to geothermal resources in the western United States are described in this report. A database of geothermal site-specific thermal gradient and heat flow results from individual exploration wells in the western US has been assembled. Extensive temperature gradient and heat flow exploration data from the active exploration of the 1970's and 1980's were collected, compiled, and synthesized, emphasizing previously unavailable company data. Examples of the use and applications of the database are described. The database and results are available on the world wide web. In this report numerical models are used to establish basic qualitative relationships between structure, heat input, and permeability distribution, and the resulting geothermal system. A series of steady state, two-dimensional numerical models evaluate the effect of permeability and structural variations on an idealized, generic Basin and Range geothermal system and the results are described.

D. D. Blackwell; K. W. Wisian; M. C. Richards; J. L. Steele

2000-04-01T23:59:59.000Z

320

Evaporation heat transfer and friction characteristics of R-134a flowing downward in a vertical corrugated tube  

SciTech Connect (OSTI)

Differently from most previous studies, the heat transfer and friction characteristics of the pure refrigerant HFC-134a during evaporation inside a vertical corrugated tube are experimentally investigated. The double tube test sections are 0.5 m long with refrigerant flowing in the inner tube and heating water flowing in the annulus. The inner tubes are one smooth tube and two corrugated tubes, which are constructed from smooth copper tube of 8.7 mm inner diameter. The test runs are performed at evaporating temperatures of 10, 15, and 20 C, heat fluxes of 20, 25, and 30 kW/m{sup 2}, and mass fluxes of 200, 300, and 400 kg/m{sup 2} s. The quality of the refrigerant in the test section is calculated using the temperature and pressure obtained from the experiment. The pressure drop across the test section is measured directly by a differential pressure transducer. The effects of heat flux, mass flux, and evaporation temperature on the heat transfer coefficient and two-phase friction factor are also discussed. It is found that the percentage increases of the heat transfer coefficient and the two-phase friction factor of the corrugated tubes compared with those of the smooth tube are approximately 0-10% and 70-140%, respectively. (author)

Aroonrat, Kanit; Wongwises, Somchai [Fluid Mechanics, Thermal Engineering and Multiphase Flow Research Lab. (FUTURE), Department of Mechanical Engineering, King Mongkut's University of Technology Thonburi, Bangmod, Bangkok 10140 (Thailand)

2011-01-15T23:59:59.000Z

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
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321

Municipal District Heating and Cooling Co-generation System Feasibility Research  

E-Print Network [OSTI]

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...

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

2006-01-01T23:59:59.000Z

322

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

SciTech Connect (OSTI)

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.

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

323

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

SciTech Connect (OSTI)

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.

None

2002-10-01T23:59:59.000Z

324

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

325

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

SciTech Connect (OSTI)

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)

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

326

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

SciTech Connect (OSTI)

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.

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

327

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

DOE Patents [OSTI]

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.

Meisner, Gregory P; Yang, Jihui

2014-02-11T23:59:59.000Z

328

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

SciTech Connect (OSTI)

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.

Sherrell, D.L.

1992-06-01T23:59:59.000Z

329

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

SciTech Connect (OSTI)

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.

Sherrell, D.L.

1992-06-01T23:59:59.000Z

330

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

SciTech Connect (OSTI)

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.

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

331

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

SciTech Connect (OSTI)

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.

J. K. Wright

2008-04-01T23:59:59.000Z

332

Heat pump system  

DOE Patents [OSTI]

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.

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

1983-01-01T23:59:59.000Z

333

Heat pump system  

DOE Patents [OSTI]

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.

Swenson, Paul F.; Moore, Paul B.

1983-06-21T23:59:59.000Z

334

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)

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)

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

335

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

SciTech Connect (OSTI)

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.

Korosec, Michael A.

1983-11-01T23:59:59.000Z

336

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

SciTech Connect (OSTI)

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.

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

337

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

SciTech Connect (OSTI)

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.

Not Available

2010-12-01T23:59:59.000Z

338

Changes in Hepatic Blood Flow During Transcatheter Arterial Infusion with Heated Saline in Hepatic VX2 Tumor  

SciTech Connect (OSTI)

Purpose. This study evaluates the influence of transcatheter arterial infusion with heated saline on hepatic arterial and portal venous blood flows to tumor and normal hepatic tissues in a rabbit VX2 tumor model. Methods. All animal experiments were approved by the institutional animal care and use committee. Twenty rabbits with VX2 liver tumors were divided into the following two groups: (a) the treated group (n = 10), which received a 60 mL transarterial injection of 60 Degree-Sign C saline via the hepatic artery; (b) the control group (n = 10), which received a 60 mL injection of 37 Degree-Sign C saline via the hepatic artery. Using ultrasonography, the blood flows in both the portal vein and hepatic artery were measured, and the changes in the hemodynamic indices were recorded before and immediately after the injection. The changes in the tumor and normal liver tissues of the two groups were histopathologically examined by hematoxylin and eosin staining after the injection. Results. After the transcatheter arterial heated infusion, there was a decrease in the hepatic arterial blood flow to the tumor tissue, a significant decrease in the hepatic artery mean velocity (P < 0.05), and a significant increase in the resistance index (P < 0.05). On hematoxylin and eosin staining, there were no obvious signs of tissue destruction in the normal liver tissue or the tumor tissue after heated perfusion, and coagulated blood plasma was observed in the cavities of intratumoral blood vessels in the treated group. Conclusions. The changes in tumor blood flow in the rabbit VX2 tumor model were presumably caused by microthrombi in the tumor vessels, and the portal vein likely mediated the heat loss in normal liver tissue during the transarterial heated infusion.

Cao Wei, E-mail: cawe-001@163.com [Tangdu Hospital, The Fourth Military Medical University, Department of Interventional Radiology (China); Li Jing, E-mail: lijing02@fmmu.edu.cn [Tangdu Hospital, The Fourth Military Medical University, Department of Burn and Plastic Surgery (China); Wu Zhiqun, E-mail: zhiqunwu@fmmu.edu.cn [Tangdu Hospital, The Fourth Military Medical University, Department of Interventional Radiology (China); Zhou Changxi, E-mail: changxizhou@163.com [Chinese PLA General Hospital, Department of Respiratory Disease (China); Liu Xi, E-mail: xiliu@fmmu.edu.cn [Tangdu Hospital, The Fourth Military Medical University, Department of Ultrasound Diagnostics (China); Wan Yi, E-mail: yiwan@163.com [The Fourth Military Medical University, Department of Health Statistics, Institute for Health Informatics (China); Duan Yunyou, E-mail: yunyouduan@fmmu.edu.cn [Tangdu Hospital, The Fourth Military Medical University, Department of Ultrasound Diagnostics (China)

2013-06-15T23:59:59.000Z

339

Comparison of analytical models for zonal flow generation in ion-temperature-gradient mode turbulence  

SciTech Connect (OSTI)

During the past years the understanding of the multi scale interaction problems have increased significantly. However, at present there exists a flora of different analytical models for investigating multi scale interactions and hardly any specific comparisons have been performed among these models. In this work two different models for the generation of zonal flows from ion-temperature-gradient (ITG) background turbulence are discussed and compared. The methods used are the coherent mode coupling model and the wave kinetic equation model (WKE). It is shown that the two models give qualitatively the same results even though the assumption on the spectral difference is used in the (WKE) approach.

Anderson, J.; Miki, K.; Uzawa, K.; Li, J.; Kishimoto, Y. [Dept. Fundamental Energy Science, School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto, 611-0011 (Japan)

2006-11-30T23:59:59.000Z

340

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

SciTech Connect (OSTI)

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.

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

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Measurements on tones generated in a corrugated flow pipe with special attention to the influence of a low frequency  

E-Print Network [OSTI]

Measurements on tones generated in a corrugated flow pipe with special attention to the influence 2011. ISBN 978-82-8123-004-0., 2011. Summary It is well known that an air flow in a corrugated pipe might excite the longitudinal acoustic modes of the pipe. In this letter is reported experiments where

Paris-Sud XI, Université de

342

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

SciTech Connect (OSTI)

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.

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

343

Rotary magnetic heat pump  

DOE Patents [OSTI]

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.

Kirol, L.D.

1987-02-11T23:59:59.000Z

344

Rotary magnetic heat pump  

DOE Patents [OSTI]

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.

Kirol, Lance D. (Shelly, ID)

1988-01-01T23:59:59.000Z

345

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

E-Print Network [OSTI]

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

Le Roy, Robert J.

346

Cylinder wall waste heat recovery from liquid-cooled internal combustion engines utilizing thermoelectric generators.  

E-Print Network [OSTI]

?? This report is a dissertation proposal that focuses on the energy balance within an internal combustion engine with a unique coolant-based waste heat recoveryÖ (more)

Armstead, John Randall

2012-01-01T23:59:59.000Z

347

Advanced Thermoelectric Materials and Generator Technology for Automotive Waste Heat at GM  

Broader source: Energy.gov [DOE]

Overview of design, fabrication, integration, and test of working prototype TEG for engine waste heat recovery on Suburban test vehicle, and continuing investigation of skutterudite materials systems

348

Turbidity current flow over an obstacle and phases of sediment wave generation  

E-Print Network [OSTI]

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 ...

Strauss, Moshe

2011-01-01T23:59:59.000Z

349

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

E-Print Network [OSTI]

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.

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

2008-03-26T23:59:59.000Z

350

Reduced heat flow in light water (H2O) due to heavy water (D2O) William R. Gormana)  

E-Print Network [OSTI]

Reduced heat flow in light water (H2O) due to heavy water (D2O) William R. Gormana) and James D by over 1000% with the addition of heavy water. A column of light water cools from 25¬įC to 0¬įC in 11 hours, however, with the addition of heavy water it takes more than 100 hours. There is a concentration

Suzuki, Masatsugu

351

Alternatives Generation and Analysis for Heat Removal from High Level Waste Tanks  

SciTech Connect (OSTI)

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.

WILLIS, W.L.

2000-06-15T23:59:59.000Z

352

General-purpose heat source: Research and development program. Radioisotope thermoelectric generator impact tests: RTG-1 and RTG-2  

SciTech Connect (OSTI)

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.

Reimus, M.A.H.; Hinckley, J.E.; George, T.G.

1996-07-01T23:59:59.000Z

353

General-purpose heat source: Research and development program, radioisotope thermoelectric generator/thin fragment impact test  

SciTech Connect (OSTI)

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.

Reimus, M.A.H.; Hinckley, J.E.

1996-11-01T23:59:59.000Z

354

Energy Efficient Process Heating: Managing Air Flow Kevin Carpenter and Kelly Kissock  

E-Print Network [OSTI]

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

Kissock, Kelly

355

Heat transfer and flow characteristics of cooling channels in turbine blades  

E-Print Network [OSTI]

/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...

Saxena, Amit

1988-01-01T23:59:59.000Z

356

Acoustically enhanced heat exchange and drying apparatus  

DOE Patents [OSTI]

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.

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

1989-01-01T23:59:59.000Z

357

Status of Segmented Element Thermoelectric Generator for Vehicle Waste Heat Recovery  

Broader source: Energy.gov [DOE]

Discusses progress of thermoelectric generator development at BSST and assessment of potential to enter commercial operation in vehicles

358

A New Generation of Hsp90 Inhibitors: Addressing Isoform Selectivity and Heat Shock Induction  

E-Print Network [OSTI]

The 90 kDa heat shock proteins (Hsp90) are molecular chaperones that are upregulated in response to cellular stress and are responsible for the conformational maturation, activation and/or stability of more than 200 client proteins. Many...

Duerfeldt, Adam Scott

2011-12-31T23:59:59.000Z

359

Thermoelectric generator  

SciTech Connect (OSTI)

A thermoelectric generator unit is described comprising: a hot side heat exchanger including a plate having extruded retention posts projecting from one surface of the plate, and fins adapted for contact with a heating source. The fins are positioned between two of the retention posts. Retention rods are inserted between the retention posts and the base of the fins to retain the fin in thermal contact with the plate surface upon insertion of the retention rod between the engaging surface of the post and the corresponding fin. Thermoelectric semi-conductor modules are in thermal contact with the opposite side of the hot side heat exchanger plate from the contact with the fins. The modules are arranged in a grid pattern so that heat flow is directed into each of the modules from the hot side heat exchanger. The modules are connected electrically so as to combine their electrical output; and a cold side heat exchanger is in thermal contact with the modules acting as a heat sink on the opposite side of the module from the hot side heat exchanger plate so as to produce a thermal gradient across the modules.

Shakun, W.; Bearden, J.H.; Henderson, D.R.

1988-03-29T23:59:59.000Z

360

Inflow turbulence generation for eddy-resolving simulations of turbomachinery flows  

E-Print Network [OSTI]

A simple variant of recycling and rescaling method to generate inflow turbulence using unstructured grid CFD codes is presented. The method has been validated on large eddy simulation of spatially developing flat plate turbulent boundary layer. The proposed rescaling algorithm is based on the momentum thickness which is more robust and essentially obviates the need of finding the edge of the turbulent boundary layer in unstructured grid codes. Extension of this algorithm to hybrid RANS/LES type of approaches and for wall-bounded turbomachinery flows is also discussed. Results from annular diffuser with different inflow boundary layer characteristics is presented as an example application to show the utility of such an algorithm.

Arolla, Sunil K

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Manufacture and properties of continuous grain flow crankshafts for locomotive and power generation diesel engines  

SciTech Connect (OSTI)

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.

Antos, D.J.; Nisbett, E.G. [National Forge Co., Irvine, PA (United States)

1997-12-31T23:59:59.000Z

362

Temperature and thermal stress distributions for the HFIR permanent reflector generated by nuclear heating  

SciTech Connect (OSTI)

The beryllium permanent reflector of the High Flux Isotope Reactor has the main functions for slowing down and reflecting the neutrons and housing the experimental facilities. The reflector is heated as a result of the nuclear reaction. Heat is removed mainly by the cooling water passing through the densely distributed coolant holes along the vertical or axial direction of the reflector. The reflector neutronic distribution and its heating rate are calculated by J.C. Gehin of the Oak Ridge National Laboratory by applying the Monte Carlo Code MCNP. The heat transfer boundary conditions along several reflector interfaces are estimated to remove additional heat from the reflector. The present paper is to report the calculation results of the temperature and the thermal stress distributions of the permanent reflector by applying the computer aided design code I-DEAS and the finite element code ABAQUS. The present calculation is to estimate the high stress areas as a result of the new beam tube cutouts along the horizontal mid-plane of the reflector of the recent reactor upgrade project. These high stresses were not able to be calculated in the preliminary design analysis in earlier 60`s. The heat transfer boundary conditions are used in this redesigned calculation. The material constants and the acceptance criteria for the allowable stresses are mainly based on that assumed in the preliminary design report.

Chang, S.J.

1998-04-01T23:59:59.000Z

363

An experimental investigation of turbine blade heat transfer and turbine blade trailing edge cooling  

E-Print Network [OSTI]

studies have investigated the fluid flow and heat transfer behavior in high Reynolds number flows. Blair [7,8] investigated the effect of grid generated turbulence on flat plate heat transfer. He showed that turbulent heat transfer coefficient in flow... AN EXPERIMENTAL INVESTIGATION OF TURBINE BLADE HEAT TRANSFER AND TURBINE BLADE TRAILING EDGE COOLING A Dissertation by JUNGHO CHOI Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment...

Choi, Jungho

2005-02-17T23:59:59.000Z

364

Numerical analysis of laminar fluid flow and heat transfer in a parallel plate channel with normally in-line positioned plates  

E-Print Network [OSTI]

NUMERICAL ANALYSIS OF LAMINAR FLUID FLOW AND HEAT TRANSFER IN A PARALLEL PLATE CHANNEL WITH NORMALLY IN-LINE POSITIONED PLATES A Thesis by JOHN GRADY iVICMATH Submitted to the Office of Graduate Studies of Texas AkM University in partial... fulfillment of the requirements for the degree of MASTER OF SCIENCE December 1991 Major Subject: Mechanical Engineering NUMERICAL ANALYSIS OF LAMINAR FLUID FLOW AND HEAT TRANSFER IN A PARALLEL PLATE CHANNEI WITH NORMALLY IN-LINE POSITIONED PLATES A...

McMath, John Grady

2012-06-07T23:59:59.000Z

365

Effervescent heating: constraints from nearby cooling flow clusters observed with XMM-Newton  

E-Print Network [OSTI]

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.

Rocco Piffaretti; Jelle Kaastra

2006-02-16T23:59:59.000Z

366

Blow-down tests in a sodium-heated steam generator tube. [LMFBR  

SciTech Connect (OSTI)

The design of steam generators for liquid metal fast breeder reactor (LMFBR) electric power plants is based on both normal load operation and plant transient conditions. Perhaps the most severe transient to which an LMFBR steam generator may be subjected is known as the water-side isolation and dump transient, often called the blow-down transient. LMFBR steam generators must be designed to accommodate a small but finite number of the blow-down transients. The purpose of this investigation was to perform a blow-down experiment in a well instrumented, full scale, single tube model of an LMFBR steam generator. The data may be used directly in steam generator design and as a validation point for steam generator mathematical models in plant transient computer codes.

France, D.M.; Carlson, R.D.; Chiang, T.

1983-01-01T23:59:59.000Z

367

Directed motion generated by heat bath nonlinearly driven by external noise  

E-Print Network [OSTI]

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.

Jyotipratim Ray Chaudhuri; Debashis Barik; Suman Kumar Banik

2007-11-02T23:59:59.000Z

368

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

E-Print Network [OSTI]

Mallants, D. , 2002. Gas generation and migration in Boomof Post-Disposal Gas Generation in a Repository for SpentCorrosion-Induced Gas Generation in a Nuclear Waste

Xu, T.

2009-01-01T23:59:59.000Z

369

NEXT GENERATION COMMERCIAL HEAT PUMPWATER HEATER USING CARBON DIOXIDE USING DIFFERENT IMPROVEMENT APPROACHES  

SciTech Connect (OSTI)

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 %.

Chad Bowers; Michael Petersen; Stefan Elbel; Pega Hrnjak

2012-04-01T23:59:59.000Z

370

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

371

Urban Sewage Delivery Heat Transfer System (1): Flow Resistance and Energy Analysis  

E-Print Network [OSTI]

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...

Zhang, C.; Wu, R.; Li, G.; Li, X.; Huang, L.; Sun, D.

2006-01-01T23:59:59.000Z

372

Finite element analysis of conjugate heat transfer in axisymmetric pipe flows  

E-Print Network [OSTI]

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...

Fithen, Robert Miller

1987-01-01T23:59:59.000Z

373

TURBULENT HEATING OF THE DISTANT SOLAR WIND BY INTERSTELLAR PICKUP PROTONS IN A DECELERATING FLOW  

E-Print Network [OSTI]

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 ...

Isenberg, Philip A.

374

Alumina Nanoparticle Pre-coated Tubing Ehancing Subcooled Flow Boiling Cricital Heat Flux  

E-Print Network [OSTI]

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 ...

Truong, Bao H.

375

The flow structure under mixed convection in a uniformly heated vertical pipe  

E-Print Network [OSTI]

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 ...

Lee, Jeongik

2005-01-01T23:59:59.000Z

376

The Difficulty of the Heating of Cluster Cooling Flows by Sound Waves and Weak Shocks  

E-Print Network [OSTI]

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.

Yutaka Fujita; Takeru Ken Suzuki

2006-10-19T23:59:59.000Z

377

6th International Symposium on Multiphase Flow, Heat Mass Transfer and Energy Conversion Xi'an, China, 11-15 July 2009  

E-Print Network [OSTI]

6th International Symposium on Multiphase Flow, Heat Mass Transfer and Energy Conversion Xi in pipeline transportation, where it is important to identify and control bottlenecks influence on production be viewed as the hydrodynamic equivalent of the Mach number for gas flows. Simplified hydraulic theories

Al Hanbali, Ahmad

378

Gas temperature profiles at different flow rates and heating rates suffice to estimate kinetic parameters for fluidised bed combustion  

SciTech Connect (OSTI)

Experimental work on estimation kinetic parameters for combustion was conducted in a bench-scale fluidised bed (FB: 105x200mm). Combustion medium was obtained by using an electrical heater immersed into the bed. The ratio of heating rate (kJ/s) to molar flow rate of air (mol/s) regulated by a rheostat so that the heat of combustion (kJ/mol) can be synthetically obtained by an electrical power supply for relevant O{sub 2}-feedstock concentration (C{sub 0}). O{sub 2}-restriction ratio ({beta}) was defined by the ratio of O{sub 2}-feedstock concentration to O{sub 2}-air concentration (C{sub O{sub 2}-AIR}) at prevailing heating rates. Compressed air at further atmospheric pressure ({approx_equal}102.7kPa) entered the bed that was alumina particles (250{mu}m). Experiments were carried out at different gas flow rates and heating rates. FB was operated with a single charge of (1300g) particles for obtaining the T/T{sub 0} curves, and than C/C{sub 0} curves. The mathematical relationships between temperature (T) and conversion ratio (X) were expressed by combining total energy balance and mass balance in FB. Observed surface reaction rate constants (k{sub S}) was obtained from the combined balances and proposed model was also tested for these kinetic parameters (frequency factor: k{sub 0}, activation energy: E{sub A}, and reaction order: n) obtained from air temperature measurements. It was found that the model curves allow a good description of the experimental data. Thus, reaction rate for combustion was sufficiently expressed. (author)

Suyadal, Y. [Faculty of Engineering, Department of Chemical Engineering, Ankara University, 06100-Tandogan, Ankara (Turkey)

2006-07-15T23:59:59.000Z

379

Continuous-Wave Radar to Detect Defects Within Heat Exchangers and Steam Generator Tubes ; Revised September 3, 2003  

SciTech Connect (OSTI)

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.

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

380

RELAP5/MOD3 code quality assurance plan for ORNL ANS narrow channel flow and heat transfer correlations  

SciTech Connect (OSTI)

Modifications have been made to REIAP5 to account for flow and heat transfer in narrow channels between fuel plates such as found in the cores of the Advanced Neutron Source (ANS) and High Flux Isotope Reactor (HFIR) reactors. These early models were supplied by Art Ruggles of Oak Ridge National Laboratory (ORNL) and Don Fletcher of the Idaho National Engineering Laboratory (INEL) and were adapted to and implemented into RELAP5 by Rich Riemke, Rex Shumway and Ken Katsma. The purpose of this report is to document the current status of these special models in the standard version of RELAP5/MOD3 and describe the quality assurance procedures.

MIller, C.S.; Shumway, R.W.

1992-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

An integrated methodology for characterizing flow and transport processes in fractured rock  

E-Print Network [OSTI]

same model grid. Comparison with Temperature Data: Heat flowgrids, generated by an irregular, unstructured, 3-D control-volume spatial discretization, used for simulations of UZ fluid flow and heat

Wu, Yu-Shu

2007-01-01T23:59:59.000Z

382

Large-Eddy Simulation of Flow and Pollutant Transport in Urban Street Canyons with Ground Heating  

E-Print Network [OSTI]

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 ...

Li, Xian-Xiang

383

Review of fluid flow and convective heat transfer within rotating disk cavities  

E-Print Network [OSTI]

-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

Boyer, Edmond

384

Development of an Underamor 1-kW Thermoelectric Generator Waste Heat  

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 Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat Pump Models |Conduct, Parent CompanyaUSAMP AMDHeavy

385

Effect of radiative heat transfer on the coagulation dynamics of combustion-generated particles  

SciTech Connect (OSTI)

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.

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

386

GENERATION OF QUASI-PERIODIC WAVES AND FLOWS IN THE SOLAR ATMOSPHERE BY OSCILLATORY RECONNECTION  

SciTech Connect (OSTI)

We investigate the long-term evolution of an initially buoyant magnetic flux tube emerging into a gravitationally stratified coronal hole environment and report on the resulting oscillations and outflows. We perform 2.5-dimensional nonlinear numerical simulations, generalizing the models of McLaughlin et al. and Murray et al. We find that the physical mechanism of oscillatory reconnection naturally generates quasi-periodic vertical outflows, with a transverse/swaying aspect. The vertical outflows consist of both a periodic aspect and evidence of a positively directed flow. The speed of the vertical outflow (20-60 km s{sup -1}) is comparable to those reported in the observational literature. We also perform a parametric study varying the magnetic strength of the buoyant flux tube and find a range of associated periodicities: 1.75-3.5 minutes. Thus, the mechanism of oscillatory reconnection may provide a physical explanation to some of the high-speed, quasi-periodic, transverse outflows/jets recently reported by a multitude of authors and instruments.

McLaughlin, J. A.; Verth, G. [School of Computing, Engineering and Information Sciences, Northumbria University, Newcastle Upon Tyne, NE1 8ST (United Kingdom); Fedun, V.; Erdelyi, R., E-mail: james.a.mclaughlin@northumbria.ac.uk, E-mail: gary.verth@northumbria.ac.uk, E-mail: v.fedun@sheffield.ac.uk, E-mail: robertus@sheffield.ac.uk [Solar Physics and Space Plasma Research Centre (SP2RC), School of Mathematics and Statistics, University of Sheffield, Hounsfield Road, Hicks Building, Sheffield, S3 7RH (United Kingdom)

2012-04-10T23:59:59.000Z

387

A computational model for viscous fluid flow, heat transfer, and melting in in situ vitrification melt pools  

SciTech Connect (OSTI)

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.

McHugh, P.R.; Ramshaw, J.D.

1991-11-01T23:59:59.000Z

388

Electrically heated DPF start-up strategy  

DOE Patents [OSTI]

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.

Gonze, Eugene V [Pinckney, MI; Ament, Frank [Troy, MI

2012-04-10T23:59:59.000Z

389

STOCHASTIC HEATING, DIFFERENTIAL FLOW, AND THE ALPHA-TO-PROTON TEMPERATURE RATIO IN THE SOLAR WIND  

SciTech Connect (OSTI)

We extend previous theories of stochastic ion heating to account for the motion of ions along the magnetic field B . We derive an analytic expression for the temperature ratio T{sub i}/T{sub p} in the solar wind assuming that stochastic heating is the dominant ion heating mechanism, where T{sub i} is the perpendicular temperature of species i and T{sub p} is the perpendicular proton temperature. This expression describes how T{sub i}/T{sub p} depends upon U{sub i} and ?{sub ?p}, where U{sub i} is the average velocity along B of species i in the proton frame and ?{sub ?p} is the ratio of the parallel proton pressure to the magnetic pressure, which we take to be ?< 1. We compare our model with previously published measurements of alpha particles and protons from the Wind spacecraft. We find that stochastic heating offers a promising explanation for the dependence of T{sub ?}/T{sub p} on U{sub ?} and ?{sub ?p} when the fractional cross helicity and Alfvťn ratio at the proton-gyroradius scale have values that are broadly consistent with solar-wind measurements. We also predict how the temperatures of other ion species depend on their drift speeds.

Chandran, B. D. G.; Verscharen, D.; Isenberg, P. A.; Bourouaine, S. [Space Science Center and Department of Physics, University of New Hampshire, Durham, NH 03824 (United States); Quataert, E. [Astronomy Department and Theoretical Astrophysics Center, 601 Campbell Hall, The University of California, Berkeley, CA 94720 (United States); Kasper, J. C., E-mail: benjamin.chandran@unh.edu, E-mail: s.bourouaine@unh.edu, E-mail: phil.isenberg@unh.edu, E-mail: daniel.verscharen@unh.edu, E-mail: eliot@astro.berkeley.edu, E-mail: jkasper@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

2013-10-10T23:59:59.000Z

390

Role of ion mass in the generation of fluctuations and poloidal flows in a simple toroidal plasma  

SciTech Connect (OSTI)

Generation of fluctuations and poloidal flow is investigated in a simple toroidal plasma, at a given magnetic field strength for varying ion masses. Under similar discharge conditions, the fluctuation induced poloidal flux is found to decrease with increasing ion mass. Consequently, the absolute net poloidal flow velocity is found to scale down systematically with increase in the ion mass. The net poloidal flow in units of ion acoustic velocity is, however, comparable for all masses on the low field side and shows minor variations on the high field side. The frequency of the first harmonic in the density and potential power spectra is found to decrease with decreasing absolute net flow. A transition occurs in the fluctuation behavior from highly coherent state to a turbulent state with increase in the ion mass, from argon to xenon.

Goud, T. S.; Ganesh, R.; Saxena, Y. C.; Raju, D. [Institute for Plasma Research, Gandhinagar 382428 Gujarat (India)

2012-07-15T23:59:59.000Z

391

High Temperature Fuel Cell Tri-Generation of Power, Heat & H2 from Biogas |  

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 Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensional Subject:Ground Hawaii HIGH PERFORMANCE andHigh Risk PlanD

392

Chemical heat pump  

DOE Patents [OSTI]

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.

Greiner, Leonard (2750-C Segerstrom Ave., Santa Ana, CA 92704)

1980-01-01T23:59:59.000Z

393

Opportunities for Combined Heat and Power at Wastewater Treatment...  

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

option for WWTFs that have, or are planning to install, anaerobic digesters. The biogas flow from the digester can be used as fuel to generate electricity and heat in a CHP...

394

Method and apparatus for fuel gas moisturization and heating  

DOE Patents [OSTI]

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.

Ranasinghe, Jatila (Niskayuna, NY); Smith, Raub Warfield (Ballston Lake, NY)

2002-01-01T23:59:59.000Z

395

Columbia University Flow Instability Experimental Program, Volume 10: Critical Heat Flux Test Program data tables  

SciTech Connect (OSTI)

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.

Coutts, D.A.

1993-09-01T23:59:59.000Z

396

Transient fluid and heat flow modeling in coupled wellbore/reservoir systems  

E-Print Network [OSTI]

....................................................... 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...

Izgec, Bulent

2009-05-15T23:59:59.000Z

397

Spring temperatures in the Sagehen Basin, Sierra Nevada, CA: implications for heat flow and groundwater circulation  

E-Print Network [OSTI]

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

Manga, Michael

398

Imaging of the Self-Excited Oscillation of Flow Past a Cavity During Generation of a Flow Tone  

SciTech Connect (OSTI)

Flow through a pipeline-cavity system can give rise to pronounced flow tones, even when the inflow boundary layer is fully turbulent. Such tones arise from the coupling between the inherent instability of the shear flow past the cavity and a resonant acoustic mode of the system. A technique of high-image-density particle image velocimetry is employed in conjunction with a special test section, which allows effective laser illumination and digital acquisition of patterns of particle images. This approach leads to patterns of velocity, vorticity, streamline topology and hydrodynamic contributions to the acoustic power integral. Comparison of global, instantaneous images with time- and phase-averaged representations provides insight into the small-scale and large-scale concentrations of vorticity, and their consequences on the topological features of Streamline patterns, as well as the streamwise and transverse projections of the hydrodynamic contribution to the acoustic power integral. Furthermore, these global approaches allow the definition of effective wavelengths and phase speeds of the vortical structures, which can lead to guidance for physical models of the dimensionless frequency of oscillation.

M. Geveci; P. Oshkai; D. Rockwell; J-C. Lin; M. Pollack

2002-05-21T23:59:59.000Z

399

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]

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

Abdou, Mohamed

400

Rotor bore and turbine rotor wheel/spacer heat exchange flow circuit  

DOE Patents [OSTI]

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.

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

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

A Low-Cost, High-Efficiency Periodic Flow Gas Turbine for Distributed Energy Generation  

SciTech Connect (OSTI)

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.

Dr. Adam London

2008-06-20T23:59:59.000Z

402

Co-generation of electricity and heat from combustion of wood powder utilizing thermophotovoltaic conversion  

SciTech Connect (OSTI)

The development of a thermophotovoltaic converter that uses combustion of wood powder as energy source has started with development of the combustion source. During the last few months, we have constructed and tested a feeding mechanism and a combustion chamber that seem very promising. We manage to keep a 10 kW flame steadily burning for several minutes at the time, generating a temperature exceeding 1400 K. The plans for continued development of this and other components of the converter are discussed in the paper. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

Broman, L. [Solar Energy Research Center, University College of Falun/Borlaenge, P.O. Box 10044, S-781 10 Borlaenge, Sweden, Phone +46 2437 3747, fax 3750, e-mail lbratt.hfb.se (Sweden); Marks, J. [Department of Operational Efficiency, Swedish University of Agricultural Sciences S-776 98 Garpenberg, Sweden, Phone +46 2252 6068, fax 2162 (Sweden)

1995-01-05T23:59:59.000Z

403

FRAC-STIM: A Physics-Based Fracture Simulation, /reservoir Flow and Heat  

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 Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat PumpRecord ofESPCofConstruction Management14,2 - In theJulyDepartment of-Transport

404

Geothermal Resource-Reservoir Investigations Based On Heat Flow And Thermal  

Open Energy Info (EERE)

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 Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat Jump to: navigation, search OpenEIOpenInformation ExplorationGradient

405

Heat Flow And Geothermal Potential In The South-Central United States |  

Open Energy Info (EERE)

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 Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat Jump to:Photon Place:NetHealth Division |Hays,Community College Jump

406

Heat Flow Determinations and Implied Thermal Regime of the Coso Geothermal  

Open Energy Info (EERE)

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 Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat Jump to:Photon Place:NetHealth Division |Hays,Community College JumpArea

407

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

Open Energy Info (EERE)

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 Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat Jump to:Photon Place:NetHealth Division |Hays,Community College

408

Heat flow determinations and implied thermal regime of the Coso geothermal  

Open Energy Info (EERE)

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 Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat Jump to:Photon Place:NetHealth Division |Hays,Communityarea, California |

409

Heat flow in the northern Basin and Range province | Open Energy  

Open Energy Info (EERE)

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 Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat Jump to:Photon Place:NetHealth Division |Hays,Communityarea, California

410

Industrial Waste Heat Recovery Using Heat Pipes  

E-Print Network [OSTI]

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...

Ruch, M. A.

1981-01-01T23:59:59.000Z

411

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]

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...

Zhong, L.

2014-01-01T23:59:59.000Z

412

System and method for generating current by selective minority species heating  

DOE Patents [OSTI]

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.

Fisch, Nathaniel J. (Princeton, NJ)

1983-01-01T23:59:59.000Z

413

An Experimental Study of Upward and Downward Flow of Supercritical Carbon Dioxide in a Straight Pipe Heat Exchanger with Constant Wall Heat Flux  

E-Print Network [OSTI]

An experimental analysis was conducted on a single circular tube heat exchanger using supercritical carbon dioxide as the working fluid. The heat exchanger was operated in two different orientations: vertically upward and downward. The experimental...

Umrigar, Eric Dara

2014-05-01T23:59:59.000Z

414

An analysis of the flow of heat from tubes buried in a concrete slab  

E-Print Network [OSTI]

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...

Holdredge, Ernest C

1951-01-01T23:59:59.000Z

415

TOUGH2: A general-purpose numerical simulator for multiphase fluid and heat flow  

SciTech Connect (OSTI)

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.

Pruess, K.

1991-05-01T23:59:59.000Z

416

Segmented heat exchanger  

DOE Patents [OSTI]

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.

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

417

The effect of velocity boundary conditions on the heat transfer and flow topology in two-dimensional Rayleigh-B\\'enard convection  

E-Print Network [OSTI]

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...

van der Poel, Erwin P; Verzicco, Roberto; Lohse, Detlef

2015-01-01T23:59:59.000Z

418

Air Flow Distribution in the Sales Area of a Supermarket  

E-Print Network [OSTI]

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...

Fang, X.; Song, C.; Zhao, J.; Wang, Z.

2006-01-01T23:59:59.000Z

419

Results of temperature gradient and heat flow in Santiam Pass Area, Oregon, Volume 1  

SciTech Connect (OSTI)

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.

Cox, B.L.; Gardner, M.C.; Koenig, J.B.

1981-08-01T23:59:59.000Z

420

Liquid Salts as Media for Process Heat Transfer from VHTR's: Forced Convective Channel Flow Thermal Hydraulics, Materials, and Coating  

SciTech Connect (OSTI)

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

Kumar Sridharan; Mark Anderson; Todd Allen; Michael Corradini

2012-01-30T23:59:59.000Z

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

OPTIMIZATION AND DESIGN GUIDELINES FOR HIGH FLUX MICRO-CHANNEL HEAT SINKS FOR LIQUID AND GASEOUS SINGLE-PHASE FLOW  

E-Print Network [OSTI]

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

M√ľller, Norbert

422

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

E-Print Network [OSTI]

simplified view of this second process can be seen in Figure 0.6. This ďblade-bladeĒ interaction noise contributes to both the fan and the compressor noise seen in Figure 0.5. It is commonly assumed that the background steady flow, to which the vortical...

Ayton, Lorna Jane

2014-10-07T23:59:59.000Z

423

Computational mass transfer moduling of flow through a photocatalytic oxygen generator  

E-Print Network [OSTI]

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 ...

KŲksal, Erin (Erin Sevim)

2008-01-01T23:59:59.000Z

424

Economic Analysis and Optimization of Exterior Insulation Requirements for Ventilated Buildings at Power Generation Facilities with High Internal Heat Gain  

E-Print Network [OSTI]

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...

Hughes, Douglas E.

2010-12-17T23:59:59.000Z

425

Analysis of reactor material experiments investigating oxide fuel crust stability and heat transfer in jet impingement flow  

SciTech Connect (OSTI)

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.

Sienicki, J.J.; Spencer, B.W.

1985-01-01T23:59:59.000Z

426

Update and assessment of geothermal economic models, geothermal fluid flow and heat distribution models, and geothermal data bases  

SciTech Connect (OSTI)

Numerical simulation models and data bases that were developed for DOE as part of a number of geothermal programs have been assessed with respect to their overall stage of development and usefulness. This report combines three separate studies that focus attention upon: (1) economic models related to geothermal energy; (2) physical geothermal system models pertaining to thermal energy and the fluid medium; and (3) geothermal energy data bases. Computerized numerical models pertaining to the economics of extracting and utilizing geothermal energy have been summarized and catalogued with respect to their availability, utility and function. The 19 models that are discussed in detail were developed for use by geothermal operators, public utilities, and lending institutions who require a means to estimate the value of a given resource, total project costs, and the sensitivity of these values to specific variables. A number of the models are capable of economically assessing engineering aspects of geothermal projects. Computerized simulations of heat distribution and fluid flow have been assessed and are presented for ten models. Five of the models are identified as wellbore simulators and five are described as reservoir simulators. Each model is described in terms of its operational characteristics, input, output, and other pertinent attributes. Geothermal energy data bases are reviewed with respect to their current usefulness and availability. Summaries of eight data bases are provided in catalogue format, and an overall comparison of the elements of each data base is included.

Kenkeremath, D. (ed.)

1985-05-01T23:59:59.000Z

427

Magnetic field distribution in the plasma flow generated by a plasma focus discharge  

SciTech Connect (OSTI)

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.

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

428

One- and two-dimensional Stirling machine simulation using experimentally generated reversing flow turbuulence models  

SciTech Connect (OSTI)

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.

Goldberg, L.F. [Univ. of Minnesota, Minneapolis, MN (United States)

1990-08-01T23:59:59.000Z

429

Heat pump system  

DOE Patents [OSTI]

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.

Swenson, Paul F. (Cleveland, OH); Moore, Paul B. (Fedhaurn, FL)

1982-01-01T23:59:59.000Z

430

ESTIMATION OF OUTLET MASS FLOW FOR A MONO-TUBE CAVITY RECEIVER FOR DIRECT STEAM GENERATION  

E-Print Network [OSTI]

University (ANU). Solar thermal power plants using this technology are intended to be deployed in large generation with large scale parabolic dishes. Simulations of the model show that it is possible to assume pressure and modelled fluid properties. Simulations show that this approach produces good agreement between

431

Automatic Test Generation for Data-Flow Reactive Systems with time constraints  

E-Print Network [OSTI]

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

Boyer, Edmond

432

Two-phase flow interfacial drag for once through steam generators  

E-Print Network [OSTI]

of the most important components in pressurized water reactors (PWR). Predictions of the steady-state and transient behavior of steam generators are essential for the study of load following capabilities and anticipated operating transients. Therefore... is to provide the U. S. Nuclear Regulatory Commission with a fast running and user convenient light water reactor system transient analysis code for use in rule making and a basis for a nuclear plant analyzer. The new feature of the RELAP5 series is the use...

Rais, Omar Tahar

1990-01-01T23:59:59.000Z

433

The Impact of Refrigerant Charge, Air Flow and Expansion Devices on the Measured Performance of an Air-Source Heat Pump Part I  

SciTech Connect (OSTI)

This paper describes extensive tests performed on a 3-ton R-22 split heat pump in heating mode. The tests contain 150 steady-state performance tests, 18 cyclic tests and 18 defrost tests. During the testing work, the refrigerant charge level was varied from 70 % to 130% relative to the nominal value; the outdoor temperature was altered by three levels at 17 F (-8.3 C), 35 F (1.7 C) and 47 F (8.3 C); indoor air flow rates ranged from 60% to 150% of the rated air flow rate; and the expansion device was switched from a fixed-orifice to a thermal expansion value. Detailed performance data from the extensive steady state cyclic and defrost testing performed were presented and compared.

Shen, Bo [ORNL

2011-01-01T23:59:59.000Z

434

Superconductivity for Electric Systems Program Review LANL Contributions to GE HTS Generator  

E-Print Network [OSTI]

-section · Develop a heat generation profile => thermal analysis #12;Superconductivity for Electric Systems Program of coolant loop to verify heat due to flow work on helium #12;Superconductivity for Electric Systems Program for Electric Systems Program Review Stationary heat pipe tests were necessary to determine performance impact

435

Quantum models with spectrum generated by the flows of polynomial zeros  

E-Print Network [OSTI]

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\

Alexander Moroz

2014-10-27T23:59:59.000Z

436

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)

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.

Lee, K.H.; Lee, J.S.; Choi, M. [Seoul National Univ. (Korea, Republic of). Dept. of Mechanical Engineering

1996-02-09T23:59:59.000Z

437

Deceleration of Alpha Particles in the Solar Wind by Instabilities and the Rotational Force: Implications for Heating, Azimuthal Flow, and the Parker Spiral Magnetic Field  

E-Print Network [OSTI]

Protons and alpha particles in the fast solar wind are only weakly collisional and exhibit a number of non-equilibrium features, including relative drifts between particle species. Two non-collisional mechanisms have been proposed for limiting differential flow between alpha particles and protons: plasma instabilities and the rotational force. Both mechanisms decelerate the alpha particles. In this paper, we derive an analytic expression for the rate $Q_{\\mathrm{flow}}$ at which energy is released by alpha-particle deceleration, accounting for azimuthal flow and conservation of total momentum. We find that $Q_{\\mathrm{flow}} > 0 $ at $r r_{\\mathrm{crit}}$. We compare the value of $Q_{\\mathrm{flow}}$ at $r< r_{\\mathrm{crit}}$ with empirical heating rates for protons and alpha particles, denoted $Q_{\\mathrm{p}}$ and $Q_{\\alpha}$, deduced from in-situ measurements of fast-wind streams from the Helios and Ulysses spacecraft. We find that $Q_{\\mathrm{flow}}$ exceeds $Q_{\\alpha}$ at $r < 1\\,\\mathrm{AU}$, $Q_{...

Verscharen, Daniel; Bourouaine, Sofiane; Hollweg, Joseph V

2014-01-01T23:59:59.000Z

438

The Confusing Allure of Combined Heat and Power: The Financial Attraction and Management Challenge of Reducing Energy Spend and Resulting Carbon Emissions Through Onsite Power Generation  

E-Print Network [OSTI]

efficient system that produces power (electricity, mechanical power or thermal energy), then captures the waste heat created by the power generation process and reuses it to help meet any of a variety of needs the user may have in a facility. While... a huge increase in energy reliability to a facility. This can help the user avoid the risk of the devastating financial loss that can come when grid-supplied power is interrupted. CHP reliability, however, should not be taken for granted...

Davis, R.

439

Development and adaptation of conduction and radiation heat-transfer computer codes for the CFTL. [Core Flow Test Loop; RODCON; HOTTEL  

SciTech Connect (OSTI)

RODCON and HOTTEL are two computational methods used to calculate thermal and radiation heat transfer for the Core Flow Test Loop (CFTL) analysis efforts. RODCON was developed at ORNL to calculate the internal temperature distribution of the fuel rod simulator (FRS) for the CFTL. RODCON solves the time-dependent heat transfer equation in two-dimensional (R angle) cylindrical coordinates at an axial plane with user-specified radial material zones and time- and position-variant surface conditions at the FRS periphery. Symmetry of the FRS periphery boundary conditions is not necessary. The governing elliptic, partial differential heat equation is cast into a fully implicit, finite-difference form by approximating the derivatives with a forward-differencing scheme with variable mesh spacing. The heat conduction path is circumferentially complete, and the potential mathematical problem at the rod center can be effectively ignored. HOTTEL is a revision of an algorithm developed by C.B. Baxi at the General Atomic Company (GAC) to be used in calculating radiation heat transfer in a rod bundle enclosed in a hexagonal duct. HOTTEL uses geometric view factors, surface emissivities, and surface areas to calculate the gray-body or composite view factors in an enclosure having multiple reflections in a nonparticipating medium.

Conklin, J.C.

1981-08-01T23:59:59.000Z

440

Selection of Correlations and Look-Up Tables for Critical Heat Flux Prediction in the Generation IV "IRIS" Reactor  

E-Print Network [OSTI]

In order to fulfill the goals set forth by the Generation IV International Forum, the current NERI funded

Romano, A.

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Chaotic flow in a 2D natural convection loop with heat flux boundaries William F. Louisos a,b,  

E-Print Network [OSTI]

the nonlinear dynamics of unstable convection in a 2D thermal convection loop (i.e., thermosyphon) with heat behavior and residence time in a cir- culatory direction are explored and described for the various thermal-storms depicted as a classic `bow echo' on radar [3]; land and sea breezes as a result of differential heating

Danforth, Chris

442

Probing Hot Electron Flow Generated on Pt Nanoparticles with Au/TiO2 Schottky Diodes during Catalytic CO Oxidation  

SciTech Connect (OSTI)

Hot electron flow generated on colloid platinum nanoparticles during exothermic catalytic carbon monoxide oxidation was directly detected with Au/TiO{sub 2} diodes. Although Au/TiO{sub 2} diodes are not catalytically active, platinum nanoparticles on Au/TiO{sub 2} exhibit both chemicurrent and catalytic turnover rate. Hot electrons are generated on the surface of the metal nanoparticles and go over the Schottky energy barrier between Au and TiO{sub 2}. The continuous Au layer ensures that the metal nanoparticles are electrically connected to the device. The overall thickness of the metal assembly (nanoparticles and Au thin film) is comparable to the mean free path of hot electrons, resulting in ballistic transport through the metal. The chemicurrent and chemical reactivity of nanoparticles with citrate, hexadecylamine, hexadecylthiol, and TTAB (Tetradecyltrimethylammonium Bromide) capping agents were measured during catalytic CO oxidation at pressures of 100 Torr O{sub 2} and 40 Torr CO at 373-513 K. We found that chemicurrent yield varies with each capping agent, but always decreases with increasing temperature. We suggest that this inverse temperature dependence is associated with the influence of charging effects due to the organic capping layer during hot electron transport through the metal-oxide interface.

Park, Jeong Y.; Lee, Hyunjoo; Renzas, J. Russell; Zhang, Yawen; Somorjai, G.A.

2008-05-01T23:59:59.000Z

443

Dual source heat pump  

DOE Patents [OSTI]

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.

Ecker, Amir L. (Dallas, TX); Pietsch, Joseph A. (Dallas, TX)

1982-01-01T23:59:59.000Z

444

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.

445

Fluidized bed heat treating system  

DOE Patents [OSTI]

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.

Ripley, Edward B; Pfennigwerth, Glenn L

2014-05-06T23:59:59.000Z

446

Process for oil shale retorting using gravity-driven solids flow and solid-solid heat exchange  

DOE Patents [OSTI]

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.

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

447

Process for oil shale retorting using gravity-driven solids flow and solid-solid heat exchange  

DOE Patents [OSTI]

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.

Lewis, A.E.; Braun, R.L.; Mallon, R.G.; Walton, O.R.

1983-09-21T23:59:59.000Z

448

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

E-Print Network [OSTI]

with ¬Ę¬°¬§¬£¬¶¬•¬ß ¬®¬°¬© blocks in a Yucca Mountain nuclear waste site study. Keywords. Ground water flow, grid partitioning management for the evaluation of the Yucca Mountain site as a repository for nuclear wastes. In this context of developing a 3D flow model of the Yucca Mountain site, involving computational grids of to blocks

Elmroth, Erik

449

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

E-Print Network [OSTI]

6 blocks in a Yucca Mountain nuclear waste site study. Keywords. Ground water flow, grid of Energy's civilian nuclear waste management for the evaluation of the Yucca Mountain site as a repository is currently in charge of developing a 3D flow model of the Yucca Mountain site, involving computational grids

Elmroth, Erik

450

Woven heat exchanger  

DOE Patents [OSTI]

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.

Piscitella, R.R.

1984-07-16T23:59:59.000Z

451

Development of Micro/Nano-Scale Sensors for Investigation of Heat Transfer in Multi-Phase Flows  

E-Print Network [OSTI]

surfaces. Similar experiments were also performed on a pure copper surface. In addition, experiments were performed using compact condensers. Micro-scale patterns fabricated on the refrigerant side of the compact heat exchanger were observed to cause...

Jeon, Sae Il

2012-10-19T23:59:59.000Z

452

Heating system  

SciTech Connect (OSTI)

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.

Nishman, P.J.

1983-03-08T23:59:59.000Z

453

Condensation in horizontal heat exchanger tubes  

SciTech Connect (OSTI)

Many innovative reactor concepts for Generation III nuclear power plants use passive safety equipment for residual heat removal. These systems use two phase natural circulation. Heat transfer to the coolant results in a density difference providing the driving head for the required mass flow. By balancing the pressure drop the system finds its operational mode. Therefore the systems depend on a strong link between heat transfer and pressure drop determining the mass flow through the system. In order to be able to analyze these kind of systems with the help of state of the art computer codes the implemented numerical models for heat transfer, pressure drop or two phase flow structure must be able to predict the system performance in a wide parameter range. Goal of the program is to optimize the numerical models and therefore the performance of computer codes analyzing passive systems. Within the project the heat transfer capacity of a heat exchanger tube will be investigated. Therefore the tube will be equipped with detectors, both temperature and pressure, in several directions perpendicular to the tube axis to be able to resolve the angular heat transfer. In parallel the flow structure of a two phase flow inside and along the tube will be detected with the help of x-ray tomography. The water cooling outside of the tube will be realized by forced convection. It will be possible to combine the flow structure measurement with an angular resolved heat transfer for a wide parameter range. The test rig is set up at the TOPLFOW facility at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), so that it will be possible to vary the pressure between 5 and 70 bar. The steam mass content will be varied between 0 and 100 percent. The results will be compared to the large scaled Emergency Condenser Tests performed at the INKA test facility in Karlstein (Germany). The paper will explain the test setup and the status of the project will be presented. (authors)

Leyer, S.; Zacharias, T.; Maisberger, F.; Lamm, M. [AREVA NP GmbH, Paul-Gossen-Strasse 100, Erlangen, 91052 (Germany); Vallee, C.; Beyer, M.; Hampel, U. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Bautzner Landstrasse 400, Dresden, 01328 (Germany)

2012-07-01T23:59:59.000Z

454

GEOTHERMAL POWER GENERATION PLANT  

SciTech Connect (OSTI)

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.

Boyd, Tonya

2013-12-01T23:59:59.000Z

455

Numerical simulation of the fluid flow and heat transfer processes during scavenging in a two-stroke engine under steady-state conditions  

SciTech Connect (OSTI)

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.

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

456

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)

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.

Lin, Y.T.; Choi, M.; Greif, R. (Univ. of California, Berkeley (USA))

1991-05-01T23:59:59.000Z

457

Study of instabilities and quasi-two-dimensional turbulence in volumetrically heated magnetohydrodynamic flows in a vertical rectangular duct  

E-Print Network [OSTI]

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

Abdou, Mohamed

458

Multidimensional numerical modeling of heat exchangers. [LMFBR  

SciTech Connect (OSTI)

A comprehensive, multidimensional, thermal-hydraulic model is developed for the analysis of shell-and-tube heat exchangers for liquid-metal services. For the shellside fluid, the conservation equations of mass, momentum, and energy for continuum fluids are modified using the concept of porosity, surface permeability and distributed resistance to account for the blockage effects due to the presence of heat-transfer tubes, flow baffles/shrouds, the support plates, etc. On the tubeside, the heat-transfer tubes are connected in parallel between the inlet and outlet plenums, and tubeside flow distribution is calculated based on the plenum-to-plenum pressure difference being equal for all tubes. It is assumed that the fluid remains single-phase on the shell side and may undergo phase-change on the tube side, thereby simulating the conditions of Liquid Metal Fast Breeder Reactor (LMFBR) intermediate heat exchangers (IHX) and steam generators (SG).

Sha, W.T.; Yang, C.I.; Kao, T.T.; Cho, S.M.

1982-01-01T23:59:59.000Z

459

Entropy generation minimization of a heat and mass exchanger for use in a humidification-dehumidification desalination system  

E-Print Network [OSTI]

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 ...

Thiel, Gregory P

2012-01-01T23:59:59.000Z

460

Project Title: Small Scale Electrical Power Generation from Heat Co-Produced in Geothermal Fluids: Mining Operation  

SciTech Connect (OSTI)

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.

Clark, Thomas M [Principal Investigator; Erlach, Celeste [Communications Mgr.

2014-12-30T23:59:59.000Z

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Utilizing the heat content of gas-to-liquids by-product streams for commercial power generation  

E-Print Network [OSTI]

-SeparationUnit........................................................................18 3.4.3SyngasGeneration..........................................................................18 3.4.4Fischer-Tropsch(FT)Synthesis.....................................................20 viii CHAPTER Page 3.4.5Product...Description TherearethreestagesinvolvedintheconversionofnaturalgasintoGTLfuels-Syngas generation,Fischer-Tropsch(FT)synthesis,andProductupgrade.Adetailedresultofthe processmodelinginAspenPlusisincludedinAppendixB,whiletheactualprocessmap isshowninFigureA1inAppendixAandFigure3.1below. 17...

Adegoke, Adesola Ayodeji

2006-10-30T23:59:59.000Z

462

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)

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.

Steward, D.; Penev, M.; Saur, G.; Becker, W.; Zuboy, J.

2013-06-01T23:59:59.000Z

463

Comparison of binary mixture heat and mass transfer analysis with single-component heat and mass transfer analysis in the design of GAX absorber/desorber[Generator-Absorber heat eXchange  

SciTech Connect (OSTI)

The GAX cycle is an elegant way of achieving higher effect performance with single-stage configuration. One of the key components of the GAX cycle is the absorber/desorber heat exchanger, which carries out internal heat recovery. This paper investigated two different models for the design of an absorber/desorber in the GAX system. In model A, single-component forced convective boiling with the physical properties of the mixture was assumed for the cocurrent desorption process, which is basically an approximation technique adopted widely so far. In model B, the multi-component effect of the binary mixture on the forced convective boiling transfer was considered. Significant degradation of heat and mass transfer was observed under binary mixture boiling condition as opposed to the single-component boiling. The results show that about 57% of extra heat transfer area would be needed under the case being investigated if the fluid is considered as a binary mixture rather than a single-component fluid. This paper provides a basic guideline for designing a properly sized GAX absorber-desorber.

Cao, J.; Christensen, R.N.

2000-07-01T23:59:59.000Z

464

Multiple source heat pump  

DOE Patents [OSTI]

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.

Ecker, Amir L. (Duncanville, TX)

1983-01-01T23:59:59.000Z

465

Microjet array single-phase and flow boiling heat transfer with R134a Eric A. Browne a  

E-Print Network [OSTI]

of a submerged microjet array was conducted with R134a. The staggered array of seventeen 112-lm diameter orifices blades and quench metals. Many of these practical uses of jets employ an array of jets rather than circular microjets of diameter 112 lm on a 1 √? 1 mm heater to investigate single-phase and boiling heat

Peles, Yoav

466

Turbine vanes experience high convective surface heat transfer as a consequence of the turbulent flow exiting the combustor. Before im-  

E-Print Network [OSTI]

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

Thole, Karen A.

467

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]

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

Urquiza, Eugenio

2009-01-01T23:59:59.000Z

468

ECI International Conference on Heat Transfer and Fluid Flow in Microscale Whistler, 21-26 September 2008  

E-Print Network [OSTI]

, a measure of the flow conductance of the solid matrix, depends on several factors including: porosity, particles shape and size distribution and particles arrangement. The permeability is calculated either dates back to experimental works of Carman [5] and Sullivan [6] in 1940s and theoretical analyses

Bahrami, Majid

469

Prediction of turbulent flow and local heat transfer in internally cooled turbine airfoils: the leading edge region  

E-Print Network [OSTI]

-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...

Pontaza, Juan Pablo

2013-02-22T23:59:59.000Z

470

Numerical Simulation of Flow and Heat Transfer in Internal Multi-Pass Cooling Channel within Gas Turbine Blade  

E-Print Network [OSTI]

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...

Chu, Hung-Chieh 1979-

2012-11-16T23:59:59.000Z

471

Sandia National Laboratories: Heat Exchanger Development  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

LabHeat Exchanger Development Heat Exchanger Development Planned Heat Exchanger Test Loop Capabilities Heat Exchanger 1 500 kW Heaters (Elec.) 500 kW Gas Cooler Unbalanced flows...

472

Laminar Flow Forced Convection Heat Transfer Behavior of Phase Change Material Fluid in Straight and Staggered Pin Microchannels  

E-Print Network [OSTI]

? Density Subscripts b Bulk i Inlet w Wall 1 Start of melting 2 End of melting Superscripts `` Flux - Average Acronyms CHF Constant heat glux CWT Constant wall temperature PCM Phase change material ix TABLE...:8 microchannel under T boundary condition .............. 52 Figure 32 Nusselt number for square pins geometry using CHF boundary condition ... 55 Figure 33 Nusselt number for circular pins geometry using CHF boundary condition . 55 Figure 34 Fluid...

Kondle, Satyanarayana

2011-10-21T23:59:59.000Z

473

Direct fired heat exchanger  

SciTech Connect (OSTI)

A gas-to-liquid heat exchanger system which transfers heat from a gas, generally the combustion gas of a direct-fired generator of an absorption machine, to a liquid, generally an absorbent solution. The heat exchanger system is in a counterflow fluid arrangement which creates a more efficient heat transfer.

Reimann, Robert C. (Lafayette, NY); Root, Richard A. (Spokane, WA)

1986-01-01T23:59:59.000Z

474

Experimental measurements in a radio frequency discharge heated supersonic flow: Evaluation of a potential electric propulsion thruster  

SciTech Connect (OSTI)

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.

Wantuck, P.J.; Hull, D.E.

1991-01-01T23:59:59.000Z

475

Measurements of wall heat (mass) transfer for flow through blockages with round and square holes in a wide rectangular channel  

E-Print Network [OSTI]

. . . 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...

Cervantes, Joel

2012-06-07T23:59:59.000Z

476

Generator configuration for solid oxide fuel cells  

DOE Patents [OSTI]

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.

Reichner, Philip (Plum Boro, PA)

1989-01-01T23:59:59.000Z

477

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]

2. LITERATURE REVIEW 3. OBJECTIVES TABLE OF CONTENTS Page nl tv v111 xt 4. THE EXPERIMENTAL TEST FACILITY 4. 1. Overall Layout of the Test Facility 4, 2. The Fan and Inlet Duct Assembly 4. 3. The Diffuser, Settling Chamber and Nozzle... Assembly . 4. 4. The Wake Generator to Simulate Unsteady Inlet Flow . 4, 5. The Test Section to Simulate Blade Curvature 4, 6, The Convex Wall and Traversing System 4. 7, Adjustment of the Turbulence Level 4. 8. Capabilities of the Test Facility, 5...

Pardivala, Darayus Noshir

2012-06-07T23:59:59.000Z

478

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

E-Print Network [OSTI]

: : : : : : : : : : : : : : : : : : : : : : : : 15 VI RESULTS AND DISCUSSION : : : : : : : : : : : : : : : : : : : 17 A. Effect of Reynolds Number ReDh . . . . . . . . . . . . . . 17 B. Effect of Height of Pins, H=D . . . . . . . . . . . . . . . . 21 C. Effect of Stream Wise Spacing of Pins, SL=D... Pressure Drop for D = 2:54cm : 23 9 Effect of H=D on Thermal Performance for D = 2:54cm : : : : : : : 24 10 Effect of SL=D on Heat Transfer Enhancement for D=1.27cm : : : : 25 11 Effect of SL=D on Increase of Overall Pressure Drop for D = 1:27cm 26 12...

Achanta, Vamsee Satish

2004-09-30T23:59:59.000Z

479

Dependency of Heat Transfer Rate on the Brinkman Number in Microchannels  

E-Print Network [OSTI]

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