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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

Natural convection flow over an inclined flat plate with internal heat generation and variable viscosity  

Science Conference Proceedings (OSTI)

The present investigation deals with study of laminar natural convection flow of a viscous fluid over a semi-infinite flat plate inclined at a small angle to the horizontal with internal heat generation and variable viscosity. The dimensionless boundary ... Keywords: Heat generation, Inclined flat surface, Natural convection, Temperature dependent viscosity

S. Siddiqa; S. Asghar; M. A. Hossain

2010-11-01T23:59:59.000Z

3

HEAT GENERATION  

DOE Patents (OSTI)

Heat is generated by the utilization of high energy neutrons produced as by nuclear reactions between hydrogen isotopes in a blanket zone containing lithium, a neutron moderator, and uranium and/or thorium effective to achieve multtplicatton of the high energy neutron. The rnultiplied and moderated neutrons produced react further with lithium-6 to produce tritium in the blanket. Thermal neutron fissionable materials are also produced and consumed in situ in the blanket zone. The heat produced by the aggregate of the various nuclear reactions is then withdrawn from the blanket zone to be used or otherwise disposed externally. (AEC)

Imhoff, D.H.; Harker, W.H.

1963-12-01T23:59:59.000Z

4

Combined cycle electric power plant and a heat recovery steam generator having improved boiler feed pump flow control  

SciTech Connect

A combined cycle electric power plant is described that includes gas and steam turbines and a steam generator for recovering the heat in the exhaust gases exited from the gas turbine and for using the recovered heat to produce and supply steam to the steam turbine. The steam generator includes an economizer tube and a high pressure evaporator tube and a boiler feed pump for directing the heat exchange fluid serially through the aforementioned tubes. A condenser is associated with the steam turbine for converting the spent steam into condensate water to be supplied to a deaerator for removing undesired air and for preliminarily heating the water condensate before being pumped to the economizer tube. Condensate flow through the economizer tube is maintained substantially constant by maintaining the boiler feed pump at a predetermined, substantially constant rate. A bypass conduit is provided to feed back a portion of the flow heated in the economizer tube to the deaerator; the portion being equal to the difference between the constant flow through the economizer tube and the flow to be directed through the high pressure evaporator tube as required by the steam turbine for its present load.

Martz, L.F.; Plotnick, R.J.

1976-06-29T23:59:59.000Z

5

Heat flow of Oregon  

DOE Green Energy (OSTI)

An extensive new heat flow and geothermal gradient data set for the State of Oregon is presented on a contour map of heat flow at a scale of 1:1,000,000 and is summarized in several figures and tables. The 1:1,000,000 scale heat flow map is contoured at 20 mW/m/sup 2/ (0.5 HFU) intervals. Also presented are maps of heat flow and temperature at a depth of 1 km averaged for 1/sup 0/ x 1/sup 0/ intervals. Histograms and averages of geothermal gradient and heat flow for the State of Oregon and for the various physiographic provinces within Oregon are also included. The unweighted mean flow for Oregon is 81.3 +- 2.7 mW/m/sup 2/ (1.94 +- 0.06 HFU). The average unweighted geothermal gradient is 65.3 +- 2.5/sup 0/C/km. The average heat flow value weighted on the basis of geographic area is 68 +- 5 mW/m/sup 2/ (1.63 +- 0.12 HFU) and the average weighted geothermal gradient is 55.0 +- 5/sup 0/C/km.

Blackwell, D.D.; Hull, D.A.; Bowen, R.G.; Steele, J.L.

1978-01-01T23:59:59.000Z

6

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

7

Distributed Generation Heat Recovery  

Science Conference Proceedings (OSTI)

Economic and environmental drivers are promoting the adoption of combined heat and power (CHP) systems. Technology advances have produced new and improved distributed generation (DG) units that can be coupled with heat recovery hardware to create CHP systems. Performance characteristics vary considerably among DG options, and it is important to understand how these characteristics influence the selection of CHP systems that will meet both electric and thermal site loads.

2002-03-06T23:59:59.000Z

8

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

9

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

1985-01-01T23:59:59.000Z

10

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

11

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

Open Energy Info (EERE)

Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas- Features And Examples Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat Flow,...

12

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

13

Distributed Generation with Heat Recovery and Storage  

E-Print Network (OSTI)

L ABORATORY Distributed Generation with Heat Recovery andequal opportunity employer. Distributed Generation with Heatenergy resources (DER), distributed generation (DG), and

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

2008-01-01T23:59:59.000Z

14

Micro thrust and heat generator  

DOE Patents (OSTI)

The present invention relates generally to micromachines such as microengines or micromotors. More specifically, the invention is directed to a micro rocket which functions as a source of heat and thrust, and utilizes chemical energy to drive or power micromechanical apparatuses. The invention is adaptable to applications involving defense, bio-medical, manufacturing, consumer product, aviation, automotive, computer, inspection, and safety systems. A micro thrust and heat generator has a means for providing a combustion fuel source to an ignition chamber of the micro thrust and heat generator. The fuel is ignited by a ignition means within the micro thrust and heat generator`s ignition chamber where it burns and creates a pressure. A nozzle formed from the combustion chamber extends outward from the combustion chamber and tappers down to a narrow diameter and then opens into a wider diameter where the nozzle then terminates outside of said combustion chamber. The pressure created within the combustion chamber accelerates as it leaves the chamber through the nozzle resulting in pressure and heat escaping from the nozzle to the atmosphere outside the micro thrust and heat generator. The micro thrust and heat generator can be microfabricated from a variety of materials, e.g., of polysilicon, on one wafer using surface micromachining batch fabrication techniques or high aspect ratio micromachine techniques (LIGA).

Garcia, E.J.

1995-12-31T23:59:59.000Z

15

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

Open Energy Info (EERE)

Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas- Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas- Features And Examples Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas- Features And Examples Details Activities (5) Areas (5) Regions (0) Abstract: Surface heat flow measurements over active geothermal systems indicate strongly positive thermal anomalies. Whereas in "normal" geothermal settings, the surface heat flow is usually below 100-120 mW m- 2, in active geothermal areas heat flow values as high as several watts per meter squared can be found. Systematic interpretation of heat flow patterns sheds light on heat transfer mechanisms at depth on different lateral, depth and time scales. Borehole temperature profiles in active geothermal

16

Distributed Generation with Heat Recovery and Storage  

E-Print Network (OSTI)

selection of on-site power generation with combined heat andsingle-cycle thermal power generation is typically lesshighly centralized power generation and delivery system

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

2008-01-01T23:59:59.000Z

17

Distributed Generation with Heat Recovery and Storage  

E-Print Network (OSTI)

Distributed Generation with Heat Recovery and Storage ‡energy resources (DER), distributed generation (DG), andload of Figure 2. distributed generation of part or all of

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

2005-01-01T23:59:59.000Z

18

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

Open Energy Info (EERE)

Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow Measurements Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow Measurements And Heat-Flow Estimates From The Uk Geothermal Catalogue Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow Measurements And Heat-Flow Estimates From The Uk Geothermal Catalogue Details Activities (0) Areas (0) Regions (0) Abstract: A comprehensive database of temperature, heat flow, thermal conductivity and geochemistry is the basis of geothermal modelling. The latest revision (1987) of the UK Geothermal Catalogue (UKGC) contains over 2600 temperatures at over 1150 sites and over 200 observations of heat flow. About 93% of the temperature data are from depths less than 2000 m and about 50% are Bottom Hole Temperatures (BHT). Heat-flow density

19

Recovering heat when generating power  

Science Conference Proceedings (OSTI)

Intelligent use of heat-recovery stream generators (HRSGs) is vital for the efficient operation of cogeneration plants, which furnish both thermal energy (usually in the form of steam) and electric energy. HRSGs are similarly important in combined-cycle power plants, in which the thermal energy rejected from the primary electric-power-generation step is harnessed (as discussed below) to produce additional electrical energy. In these facilities, the HRSG is typically heated by gas-turbine exhaust. Natural gas is the fuel most widely used for gas turbines in the U.S., whereas fuel oil is the main fuel in other countries. Depending on the amount of steam to be produced, HRSGs for gas-turbine-exhaust applications may be unfired, supplementary-fired or furnace fired. The paper describes these three options; the pressure drop encountered in all three systems; the Cheng cycle; catalytic reduction of nitrogen oxides and CO; and performance testing.

Ganapathy, V.

1993-02-01T23:59:59.000Z

20

Potassium, Uranium, Thorium Radiogenic Heat Contribution To Heat Flow In  

Open Energy Info (EERE)

Potassium, Uranium, Thorium Radiogenic Heat Contribution To Heat Flow In Potassium, Uranium, Thorium Radiogenic Heat Contribution To Heat Flow In The Precambrian And Younger Silicic Rocks Of The Zuni And Florida Mountains, New Mexico (Usa) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Potassium, Uranium, Thorium Radiogenic Heat Contribution To Heat Flow In The Precambrian And Younger Silicic Rocks Of The Zuni And Florida Mountains, New Mexico (Usa) Details Activities (4) Areas (2) Regions (0) Abstract: High heat flow in the Zuni Mountains, New Mexico, U.S.A., has been explained by the possible presence of a buried felsic pluton. Alternately, high K, U, Th abundances have been proposed to account for part of the high heat flow. The mean radiogenic heat contribution for 60 samples of Precambrian core rocks is 7.23 ÎĽcal/gm-yr, which is slightly

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 Transfer Enhancement in Thermoelectric Power Generation.  

E-Print Network (OSTI)

??Heat transfer plays an important role in thermoelectric (TE) power generation because the higher the heat-transfer rate from the hot to the cold side of… (more)

Hu, Shih-yung

2009-01-01T23:59:59.000Z

22

Simplify heat recovery steam generator evaluation  

SciTech Connect

Heat recovery steam generators (HRSGs) are widely used in process and power plants, refineries and in several cogeneration/combined cycle systems. They are usually designed for a set of gas and steam conditions but often operate under different parameters due to plant constraints, steam demand, different ambient conditions (which affect the gas flow and exhaust gas temperature in a gas turbine plant), etc. As a result, the gas and steam temperature profiles in the HRSG, steam production and the steam temperature differ from the design conditions, affecting the entire plant performance and economics. Also, consultants and process engineers who are involved in evaluating the performance of the steam system as a whole, often would like to simulate the performance of an HRSG under different gas flows, inlet gas temperature and analysis, steam pressure and feed water temperature to optimize the entire steam system and select proper auxiliaries such as steam turbines, condensers, deaerators, etc.

Ganapathy, V. (ABCO Industries, Abilene, TX (US))

1990-03-01T23:59:59.000Z

23

Heat engine generator control system  

SciTech Connect

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

24

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

25

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 of the process plant, cogeneration or combined cycle plant. There is no need to design the HRSG per se and hence simulation is a valuable tool for anyone interested in evaluating the HRSG performance even before it is designed. It can also save a lot of time for specification writers as they need not guess how the steam side performance will vary with different gas/steam parameters. A few examples are given to show how simulation methods can be applied to real life problems.

Ganapathy, V.

1993-03-01T23:59:59.000Z

26

New shear-free relativistic models with heat flow  

E-Print Network (OSTI)

We study shear-free spherically symmetric relativistic models with heat flow. Our analysis is based on Lie's theory of extended groups applied to the governing field equations. In particular, we generate a five-parameter family of transformations which enables us to map existing solutions to new solutions. All known solutions of Einstein equations with heat flow can therefore produce infinite families of new solutions. In addition, we provide two new classes of solutions utilising the Lie infinitesimal generators. These solutions generate an infinite class of solutions given any one of the two unknown metric functions.

A. M. Msomi; K. S. Govinder; S. D. Maharaj

2012-12-29T23:59:59.000Z

27

The Development of a Non-Equilibrium Dispersed Flow Film Boiling Heat Transfer Modeling Package.  

E-Print Network (OSTI)

??The dispersed flow film boiling (DFFB) heat transfer regime is important to several applications including cryogenics, rocket engines, steam generators, and in the safety analysis… (more)

Meholic, Michael

2011-01-01T23:59:59.000Z

28

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 in such an exchanger are derived and solved leading to an optimization problem. In this problem, the optimal subdivision of heat transfer surface to minimize required overall heat transfer surface, under certain restricted conditions, is sought. It is shown that the off-center nozzle location can be selected judiciously so as to maintain (or even improve heat transfer) while reducing the gross shellside pressure loss. Thus, the pumping costs are minimized without sacrificing heat transfer.

Singh, K. P.

1979-01-01T23:59:59.000Z

29

Heat-flow studies in Wyoming, 1979 to 1981  

DOE Green Energy (OSTI)

Thirty heat flow values completed during May 1981 for Wyoming are tabulated and updated maps of heat flow in Wyoming and adjacent areas are presented.

Decker, E.R.; Heasler, H.P.; Buelow, K.L.

1981-12-01T23:59:59.000Z

30

Microbubble Generation Using Carbon Nanotubes Heating Elements  

Science Conference Proceedings (OSTI)

The generation of microbubbles using localized microwatt heating of carbon nanotubes (CNTs) is presented in this paper. Dielectrophoretic force is used to form CNTs between micrometal electrodes. The improvement for our CNTs heater is that a thin aligned ...

Peng Xiao; W. J. Li; Ruxu Du

2011-05-01T23:59:59.000Z

31

anomalous heat generated by cold fusion  

E-Print Network (OSTI)

heat claimed to be produced by cold fusion is actually caused by errors in heat measurement. In particular, he proposes that unrecognized changes in the calibration constant are produced by changes in the locations where heat is being generated within the electrolytic cell over the duration of the measurement. Because these papers may lend unwarranted support to rejection of cold fusion claims, these erroneous arguments used by Shanahan need to be answered.

Edmund Storms

2005-01-01T23:59:59.000Z

32

SODIUM-HEATED STEAM GENERATOR DEVELOPMENT. Interim Status Report  

SciTech Connect

Design and development of a once -through sodiumheated steam generator are discussed. Research proposals are discussed for evaluating: carbon transfer and mass transfer effects in the steam generator, effect on heat transfer and two- phase flow of coiling tubes, corrosion of Croloy 21/4 in products of sodium-water reactions, procedure for welding tube to back side of the tube sheet, radiographic inspection of back side tube welds, and chemical simulation of sodium environment for leak testing. (N.W.R.)

1964-01-22T23:59:59.000Z

33

Heat Recovery Steam Generator Materials Selection Guideline  

Science Conference Proceedings (OSTI)

A considerable number of failures have occurred over the past decade in heat recovery steam generators (HRSGs). Many of these failures are attributed to poor design, improper operation, poor fabrication, or poor installation practices, but a number of them are attributed directly to improper material selection. In March 2004, the Electric Power Research Institute (EPRI) published the first heat recovery steam generator materials selection and repair guidelines (HRSG Material Selection and Repair Guidelin...

2010-12-19T23:59:59.000Z

34

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

35

Method for identifying anomalous terrestrial heat flows  

DOE Patents (OSTI)

A method for locating and mapping the magnitude and extent of terrestrial heat-flow anomalies from 5 to 50 times average with a tenfold improved sensitivity over orthodox applications of aerial temperature-sensing surveys as used for geothermal reconnaissance. The method remotely senses surface temperature anomalies such as occur from geothermal resources or oxidizing ore bodies by: measuring the spectral, spatial, statistical, thermal, and temporal features characterizing infrared radiation emitted by natural terrestrial surfaces; deriving from these measurements the true surface temperature with uncertainties as small as 0.05 to 0.5 K; removing effects related to natural temperature variations of topographic, hydrologic, or meteoric origin, the surface composition, detector noise, and atmospheric conditions; factoring out the ambient normal-surface temperature for non-thermally enhanced areas surveyed under otherwise identical environmental conditions; distinguishing significant residual temperature enhancements characteristic of anomalous heat flows and mapping the extent and magnitude of anomalous heat flows where they occur.

Del Grande, Nancy Kerr (San Leandro, CA)

1977-01-25T23:59:59.000Z

36

Waste Heat Recovery Power Generation with WOWGen  

E-Print Network (OSTI)

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 and converts it to useful output. The remaining 65% is discharged into the environment as waste heat at temperatures ranging from 300°F to 1,200°F. This waste heat can be captured using the WOWGen® technology and turned into electricity. This efficiency is up to twice the rate of competing technologies. Compelling economics and current environmental policy are stimulating industry interest. WOWGen® power plants can generate between 1 - 25 MW of electricity. Project payback is between two to five years with IRR of 15% 30%. Nearly anywhere industrial waste heat is present, the WOW products can be applied. Beneficial applications of heat recovery power generation can be found in Industry (e.g. steel, glass, cement, lime, pulp and paper, refining and petrochemicals), Power Generation (CHP, biomass, biofuel, traditional fuels, gasifiers, diesel engines) and Natural Gas (pipeline compression stations, processing plants). Sources such as stack flue gases, steam, diesel exhaust, hot oil or combinations of sources can be used to generate power. WOWGen® can also be used with stand alone power plants burning fossil fuels or using renewable energy sources such as solar and biomass.

Romero, M.

2009-05-01T23:59:59.000Z

37

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

Science Conference Proceedings (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

38

Heat Recovery Steam Generator Procurement Specification  

Science Conference Proceedings (OSTI)

Many heat recovery steam generators (HRSGs), particularly those equipped with advanced gas turbines that are subjected to periods of frequent cyclic operation, have experienced premature pressure part failures resulting from excessive thermal mechanical fatigue damage. The very competitive power generation marketplace has resulted in the lowest installed cost often taking precedence over medium- and long-term durability and operating costs. The procurement of engineer, procure, and construct ...

2013-12-20T23:59:59.000Z

39

Local Energy Generation in Barotropic Flows  

Science Conference Proceedings (OSTI)

The local growth of disturbances to a steady, nondivergent shear flow is investigated in the context of the barotropic vorticity equation (BVE). A new expression for the instantaneous energy generation rate is derived by using a local coordinate ...

R. Iacono

2002-07-01T23:59:59.000Z

40

Repair Welding Technologies For Heat Recovery Steam Generators  

Science Conference Proceedings (OSTI)

Tube failures that occur in heat recovery steam generators (HRSGs) are often caused by thermal stress or thermal shock associated with cyclic plant operation or by flow-accelerated corrosion. Many premature failures occur along the length of finned tubes or at attachment locations where tubes are joined to the upper or lower header. Because of current tube repair practices and limited access for welding, reoccurring failures are common.

2005-12-21T23:59:59.000Z

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.


41

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.

1990-12-31T23:59:59.000Z

42

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

43

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

44

Triaxial thermopile array geo-heat-flow sensor  

DOE Green Energy (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

45

Solar collector and heat and cold generator  

SciTech Connect

This invention is directed to a collector designed and positioned for installations within a predetermined range of latitudes without modification of collector position, construction, or tracking the sun's movement, and comprises a generator of hot or cold fluid by solar energy collection during the day to heat the fluid and/or chilling of the fluid at nocturnal nighttime.

Risser, J.A.

1982-04-13T23:59:59.000Z

46

Distributed Generation with Heat Recovery and Storage  

DOE Green Energy (OSTI)

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

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

2005-07-29T23:59:59.000Z

47

Heat Flow-Thermodynamic Depth Complexity in Networks  

Science Conference Proceedings (OSTI)

In this paper we establish a formal link between network complexity in terms of Birkhoff-von Newmann decompositions and heat flow complexity (in terms of quantifying the heat flowing through the network at a given inverse temperature). Furthermore, we ...

Francisco Escolano; Miguel A. Lozano; Edwin R. Hancock

2010-08-01T23:59:59.000Z

48

Distributed Generation with Heat Recovery and Storage  

SciTech Connect

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

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

2006-06-16T23:59:59.000Z

49

Heat Recovery Steam Generator Cycle Chemistry Instrumentation  

Science Conference Proceedings (OSTI)

Effective monitoring of the purity of water and steam is an integral part of any productive cycle chemistry monitoring program. The Electric Power Research Institute's (EPRI's) heat recovery steam generator (HRSG) cycle chemistry guidelines identified a group of core monitoring parameters that are considered the minimum requirements. Meeting these requirements is part of EPRI's cycle chemistry benchmarking criteria for HRSGs. In addition to the core parameters, many chemistry parameters might need to be ...

2010-11-19T23:59:59.000Z

50

Heat Recovery Steam Generator (HRSG) Deposits  

Science Conference Proceedings (OSTI)

Under-deposit corrosion represents the second leading mechanism of chemistry-influenced heat recovery steam generator (HRSG) tube failures (HTFs) and third leading cause of major availability losses. This report was prepared, in recognition of the lack of information, to assemble the state of knowledge on deposition in HRSG high-pressure (HP) evaporator tubing and to identify the major deficiencies in that knowledge. Findings of this effort can be used to establish immediate remediation and correction of...

2009-11-11T23:59:59.000Z

51

Remote Inspection Device - Heat Recovery Steam Generators  

Science Conference Proceedings (OSTI)

As heat recovery steam generators (HRSGs) have become more complex over the last 15 years, operating with multiple pressures and temperatures, operators have experienced more types of HRSG tube failures (HTFs). This report provides information on how nondestructive evaluation (NDE) can be combined with newly developed HRSG repair tooling so that operators can detect damaged tubes and verify that repaired tubes do not contain welding defects that might be detrimental to the life of the component.

2009-03-25T23:59:59.000Z

52

Heat and Momentum Fluxes Induced by Thermal Inhomogeneities with and without Large-Scale Flow  

Science Conference Proceedings (OSTI)

The authors Present an analytical evaluation of the vertical heat and momentum fluxes associated with mesoscale flow generated by periodic and isolated thermal inhomogeneities within the convective boundary layer (CBL). The influence of larger-...

G. A. Dalu; R. A. Pielke; M. Baldi; X. Zeng

1996-11-01T23:59:59.000Z

53

Hamiltonian Thermostats Fail to Promote Heat Flow  

E-Print Network (OSTI)

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

Wm. G. Hoover; Carol G. Hoover

2013-03-25T23:59:59.000Z

54

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

55

Comparison of heat transfer in solar collectors with heat pipe versus flow through absorbers  

DOE Green Energy (OSTI)

Analysis of heat transfer in solar collectors with heat pipe absorbers is compared to that for collectors with flow through absorbers. Both pumped and thermosiphon systems that produce hot water or other heated fluids are discussed. In these applications the heat pipe absorber suffers a heat transfer penalty compared with the flow through absorber, but in many cases the penalty can be minimized by proper design at the heat pipe condenser and system manifold. When the solar collector is used to drive an absorption chiller, the heat pipe absorber has better heat transfer characteristics than the flow through absorber.

Hull, J.R.

1985-01-01T23:59:59.000Z

56

GMINC - A MESH GENERATOR FOR FLOW SIMULATIONS IN FRACTURED RESERVOIRS  

E-Print Network (OSTI)

Simulation of Fluid Flow in Fractured Porous Media, Watergovern fluid flow in fractured porous media. These are (i)for Modeling Fluid and Heat Flow in fractured Porous Media,

Pruess, K.

2010-01-01T23:59:59.000Z

57

Analysis of the transient compressible vapor flow in heat pipe  

SciTech Connect

The transient compressible one-dimensional vapor flow dynamics in a heat pipe is modeled. The numerical results are obtained by using the implicit non-iterative Beam-Warming finite difference method. The model is tested for simulated heat pipe vapor flow and actual vapor flow in cylindrical heat pipes. A good comparison of the present transient results for the simulated heat pipe vapor flow with the previous results of a two-dimensional numerical model is achieved and the steady state results are in agreement with the existing experimental data. The transient behavior of the vapor flow under subsonic, sonic, and supersonic speeds and high mass flow rates are successfully predicted. The one-dimensional model also describes the vapor flow dynamics in cylindrical heat pipes at high temperatures.

Jang, J.H.; Faghri, A. [Wright State Univ., Dayton, OH (United States); Chang, W.S. [Wright Research and Development Center, Wright-Patterson, OH (United States)

1989-07-01T23:59:59.000Z

58

Flow modification in McGill Heat Pipes.  

E-Print Network (OSTI)

??A heat pipe is a heat transfer device of very high thermal conductance that features two-phase flow. Research at McGill University has led to the… (more)

Lee, JuHee, 1973-

2005-01-01T23:59:59.000Z

59

Heat flow in the postquasistatic approximation  

Science Conference Proceedings (OSTI)

We apply the postquasistatic approximation to study the evolution of spherically symmetric fluid distributions undergoing dissipation in the form of radial heat flow. For a model that corresponds to an incompressible fluid departing from the static equilibrium, it is not possible to go far from the initial state after the emission of a small amount of energy. Initially collapsing distributions of matter are not permitted. Emission of energy can be considered as a mechanism to avoid the collapse. If the distribution collapses initially and emits one hundredth of the initial mass only the outermost layers evolve. For a model that corresponds to a highly compressed Fermi gas, only the outermost shell can evolve with a shorter hydrodynamic time scale.

Rodriguez-Mueller, B. [Computational Science Research Center, College of Sciences, San Diego State University, San Diego, California (United States); Peralta, C. [Deutscher Wetterdienst, Frankfurter Strasse 135, 63067 Offenbach (Germany); School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia); Barreto, W. [Centro de Fisica Fundamental, Facultad de Ciencias, Universidad de Los Andes, Merida (Venezuela, Bolivarian Republic of); Rosales, L. [Laboratorio de Fisica Computacional, Universidad Experimental Politecnica, 'Antonio Jose de Sucre', Puerto Ordaz (Venezuela, Bolivarian Republic of)

2010-08-15T23:59:59.000Z

60

Local entropy generation analysis of a rotary magnetic heat pump regenerator  

SciTech Connect

The rotary magnetic heat pump has attractive thermodynamic performance but it is strongly influenced by the effectiveness of the regenerator. This study uses local entropy generation analysis to evaluate the regenerator design and to suggest design improvements. The results show that performance of the proposed design is dominated by heat transfer related entropy generation. This suggests that enhancement concepts that improve heat transfer should be considered, even if the enhancement causes a significant increase in viscous losses (pressure drop). One enhancement technique, the use of flow disrupters, was evaluated and the results showed that flow disrupters can significantly reduce thermodynamic losses.

Drost, M.K.; White, M.D.

1990-04-01T23:59:59.000Z

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.


61

Property:Distributed Generation System Heating-Cooling Application | Open  

Open Energy Info (EERE)

Heating-Cooling Application Heating-Cooling Application Jump to: navigation, search This is a property of type Page. Pages using the property "Distributed Generation System Heating-Cooling Application" Showing 21 pages using this property. D Distributed Generation Study/10 West 66th Street Corp + Domestic Hot Water +, Space Heat and/or Cooling + Distributed Generation Study/Aisin Seiki G60 at Hooligans Bar and Grille + Domestic Hot Water + Distributed Generation Study/Arrow Linen + Domestic Hot Water + Distributed Generation Study/Dakota Station (Minnegasco) + Space Heat and/or Cooling +, Other + Distributed Generation Study/Elgin Community College + Space Heat and/or Cooling +, Domestic Hot Water + Distributed Generation Study/Emerling Farm + Domestic Hot Water +, Process Heat and/or Cooling +

62

The International Heat Flow Commission | Open Energy Information  

Open Energy Info (EERE)

The International Heat Flow Commission The International Heat Flow Commission Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: The International Heat Flow Commission Details Activities (1) Areas (1) Regions (0) Abstract: Unavailable Author(s): A. E. Beck, V. Cermak Published: Geothermics, 1989 Document Number: Unavailable DOI: Unavailable Source: View Original Journal Article Data Acquisition-Manipulation (Beck & Cermak, 1989) Unspecified Retrieved from "http://en.openei.org/w/index.php?title=The_International_Heat_Flow_Commission&oldid=387748" Category: Reference Materials What links here Related changes Special pages Printable version Permanent link Browse properties 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation: XID: 1863774514

63

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

Open Energy Info (EERE)

determinations and implied thermal regime of the Coso geothermal area, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Heat flow...

64

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

Open Energy Info (EERE)

and (2) microearthquake studies associated with the geothermal phenomena in the Coso Hot Springs area. The sites for ten heat flow boreholes were located primarily using the...

65

Handbook of thermodynamics, heat transfer and fluid flow  

E-Print Network (OSTI)

9 Nov 2010 ... Handbook of thermodynamics, heat transfer and fluid flow | JUNE 1992 | 3 Volume | U.S. Department of Energy FSC-6910 Washington, D.C. ...

66

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

Open Energy Info (EERE)

studies, Coso Geothermal Area, China Lake, California. Technical report Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Heat flow studies, Coso Geothermal...

67

Heat-flow reconnaissance of the Gulf Coastal Plain  

DOE Green Energy (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

68

Dynamic van der Waals Theory of Two-Phase Fluids in Heat Flow Akira Onuki  

E-Print Network (OSTI)

Dynamic van der Waals Theory of Two-Phase Fluids in Heat Flow Akira Onuki Department of Physics as a functional of the order parameter and the energy density. Let us consider one-component fluids, where-component fluids the effect is drastically altered due to latent heat generation or absorption at the interface [12

69

Distributed Generation with Heat Recovery and Storage  

E-Print Network (OSTI)

Doubling combined heat and power capacity in the UnitedCost Savings from Heat Storage Capacity Figure 49. LargeR 2 = 0.6683 Heat Storage Capacity (kWh) Fig. 48 Weekday

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

2008-01-01T23:59:59.000Z

70

Distributed Generation with Heat Recovery and Storage  

E-Print Network (OSTI)

between heat storage costs and capacity can be determineda given kWh of heat storage capacity is worth to a typicalequation (22) sets the heat storage capacity to the maximum

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

2005-01-01T23:59:59.000Z

71

Distributed Generation with Heat Recovery and Storage  

E-Print Network (OSTI)

of electricity and natural gas DER No Heat Storage: thefired natural gas AC (a) Capacity of heat storage unit (but no heat storage, a 200 kW natural gas reciprocating

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

2005-01-01T23:59:59.000Z

72

Design of a heat recovery steam generator  

SciTech Connect

A gas turbine in the size range of 20,000 hp (14.9 MW) was retrofitted with a heat recovery steam generator (HRSG). The HRSG produces high pressure superheated steam for use in a steam turbine. Supplementary firing is used to more than double the steam production over the unfired case. Because of many unusual constraints, an innovative design of the HRSG was formulated. These design constraints included: a wide range of operating conditions was to be accommodated; very limited space in the existing plant; and a desire to limit the field construction work necessary in order to provide a short turnaround time. This paper discusses the design used to satisfy these conditions.

Logeais, D.R.

1984-06-01T23:59:59.000Z

73

Distributed Generation with Heat Recovery and Storage  

E-Print Network (OSTI)

of electricity and natural gas DER No Heat Storage: therecovery and storage) utility electricity and natural gasbut no heat storage, a 200 kW natural gas reciprocating

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

2008-01-01T23:59:59.000Z

74

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. The laminar flow and turbulent flow have approximately the same optimal frequency, i.e., about 8 Hz. When the pulsation source was placed in the upstream and downstream position, the heat transformation was completed dissimilarly. These results are coincident with previous experiments. The article also gives some information on the applications of the heat transformation by pulse flow in the shell and tube heat exchanger.

Chen, Y.; Zhao, J.

2006-01-01T23:59:59.000Z

75

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

76

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

77

Engineering Fundamentals - Heat Transfer & Fluid Flow, Version 6.0  

Science Conference Proceedings (OSTI)

The Heat Transfer and Fluid Flow module covers basic terms and concepts of heat transfer and fluid flow and discusses their applications in nuclear power plants. This course will help new engineers understand how their work might impact and/or be ...

2013-01-17T23:59:59.000Z

78

Distributed Generation with Heat Recovery and Storage  

E-Print Network (OSTI)

On-site thermal power generation is typically less efficienthighly centralised power generation and delivery systemProduction from US Power Generation Note this is only the

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

2005-01-01T23:59:59.000Z

79

Preventing numerical errors generated by interface-capturing schemes in compressible multi-material flows  

Science Conference Proceedings (OSTI)

In the present work, errors generated in computations of compressible multi-material flows using shock-capturing schemes are examined, specifically pressure oscillations (when the specific heats ratio is variable), but also temperature spikes and species ... Keywords: High-order accurate schemes, Interface capturing, Material discontinuities, Multi-material flows, Multifluid algorithms, Shock capturing, WENO

Eric Johnsen; Frank Ham

2012-07-01T23:59:59.000Z

80

Measurement of flow field and local heat transfer distribution on a scraped heat exchanger crystalliser surface  

E-Print Network (OSTI)

Measurement of flow field and local heat transfer distribution on a scraped heat exchanger.ravelet@laposte.net Geert-Jan Witkamp G.J.Witkamp@xs4all.nl Abstract In a cylindrical scraped heat exchanger crystallizer exchanger surface has been studied by direct measurements of the heat exchanger surface temperature

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.


81

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

82

Numerical analysis of vapor flow in a micro heat pipe  

E-Print Network (OSTI)

The vapor flow in a flat plate micro heat pipe with both uniform and linear heat flux boundary conditions has been numerically analyzed. For both types of boundary conditions, the Navier-Stokes equations with steady incompressible two-dimensional flow were solved using the SIMPLE method. The results indicate that the pressure, shear stress, and friction factor under linear heat flux boundary conditions are considerably smoother, and hence, more closely approximate the real situation. As the heat flux increases, the pressure drop increases, but the friction factor demonstrates only a slight change for different heat flux conditions. The size and shape of the micro heat pipe vapor space was shown to have a significant influence on the vapor flow behavior for micro heat pipes. When the vapor space area decreases, the pressure drop, shear stress, and friction factor all significantly increase.

Liu, Xiaoqin

1996-01-01T23:59:59.000Z

83

Examination of Heat Recovery Steam Generator (HRSG) Plants  

Science Conference Proceedings (OSTI)

Previous EPRI reports have documented problems associated with operation and maintenance of complex heat recovery steam generators (HRSGs). The EPRI report Heat Recovery Steam Generator Tube Failure Manual (1004503) provides information about known HRSG tube failures and necessary steps that can be taken to diagnose and prevent similar problems. The EPRI report Delivering High Reliability Heat Recovery Steam Generators (1004240) provides guidance for continued and reliable operation of HRSGs from initial...

2005-11-30T23:59:59.000Z

84

Heat Transfer Enhancement: Second Generation Technology  

E-Print Network (OSTI)

This paper reviews current activity in the field of enhanced heat transfer, with the aim of illustrating the technology and typical applications. Guidelines for application of enhanced surfaces are given, and practical concerns and economics are discussed. Special attention is directed toward use of enhanced surfaces in industrial process heat exchangers and heat recovery equipment.

Bergles, A. E.; Webb, R. L.

1984-01-01T23:59:59.000Z

85

Magnetohydrodynamic power generation, electromagnetic pumps, heat pipes, and thermionic convertors  

DOE Green Energy (OSTI)

The basic principles of operation, components, and design of MHD generators, electromagnetic pumps, heat pipes and thermionic converters are described. 66 references. (WHK)

Pierson, E.S.; Bonyhady, K.A.; Dunn, P.F.; Nathenson, R.D.; Uherka, K.L.

1984-01-01T23:59:59.000Z

86

Design with Constructal Theory: Steam Generators, Turbines and Heat Exchangers.  

E-Print Network (OSTI)

?? This dissertation shows that the architecture of steam generators, steam turbines and heat exchangers for power plants can be predicted on the basis of… (more)

Kim, Yong Sung

2010-01-01T23:59:59.000Z

87

NREL: Vehicle Ancillary Loads Reduction - Heat Generated Cooling  

NLE Websites -- All DOE Office Websites (Extended Search)

Heat Generated Cooling Heat Generated Cooling A counterintuitive but promising path to reducing the loads imposed by automotive air conditioning systems is to use heat-specifically the waste heat generated by engines. This can be an abundant source of energy, since most light-duty vehicles with combustion engines are only about 30% efficient at best. With that degree of thermal efficiency, an engine releases 70% of its fuel energy as waste heat through the coolant, exhaust gases, and engine compartment warm-up. During much of a typical drive cycle, the engine efficiency is even lower than 30%. As efficiency decreases, the amount of waste heat increases, representing a larger potential energy source. NREL's Vehicle Ancillary Loads Reduction (VALR) team is investigating a number of heat generated cooling technologies

88

Liquid-fluidized-bed heat exchanger flow distribution models  

DOE Green Energy (OSTI)

Allied Chemical Corporation at the Idaho National Engineering Laboratory is developing liquid-fluidized-bed shell-and-tube heat exchangers for geothermal applications. Sand fluidized by geothermal water on the shell side prevents scaling and increases heat transfer coefficients over conventional heat exchangers. Tests were conducted on two instrumented fluidized-bed heat exchanger models, constructed primarily of plexiglass, which differ in tube bundle orientation. One contains a horizontal bundle and the other a vertical tube bundle. Plexiglass construction allowed visual observation of flow patterns. The vertical model proved to have more uniform flow distribution and higher heat transfer coefficients than the horizontal model. The horizontal heat exchanger experienced piling on top of the tubes and areas of poor fluidization existed in the bed. Geometric considerations show that a horizontal design is more conducive to large flow rates than a vertical design. New design concepts for both vertical and horizontal assemblies and recommendations for further developmental work are presented.

Cole, L.T.; Allen, C.A.

1979-01-01T23:59:59.000Z

89

Distributed Generation with Heat Recovery and Storage  

E-Print Network (OSTI)

involved, supplemental absorption cooling allows downsizingwater heating and for absorption cooling) in a day SHPricedisplaced by absorption cooling. The same principle applies

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

2008-01-01T23:59:59.000Z

90

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

91

Heat Recovery Steam Generator (HRSG) Chemical Cleaning Guidelines Case Studies  

Science Conference Proceedings (OSTI)

A considerable number of combined cycle units with heat recovery steam generators (HRSGs) were installed over the past two decades worldwide, and the design complexity and operating pressures of these units increased significantly during this period. One of the goals of EPRI's Heat Recovery Steam Generator (HRSG) Dependability Program 88 is to minimize availability losses associated with HRSG tube failures. To support its members operating combined cycle units, EPRI published Heat Recovery Steam Generato...

2006-11-13T23:59:59.000Z

92

SCALE ANALYSIS OF CONVECTIVE MELTING WITH INTERNAL HEAT GENERATION  

SciTech Connect

Using a scale analysis approach, we model phase change (melting) for pure materials which generate internal heat 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. We show the time scales in which conduction and convection heat transfer dominate.

John Crepeau

2011-03-01T23:59:59.000Z

93

Geothermal investigations in Idaho. Part 8. Heat flow study of the Snake River Plain region, Idaho  

DOE Green Energy (OSTI)

The Snake River Plain of Idaho has recent lava flows and a large number of thermal springs and wells. A heat flow study was initiated which, together with available geological and geophysical information, allows a better definition of the geothermal resource and evaluation of the geothermal potential. Local geothermal anomalies were not the objects of this study and have not been studied in detail. The quality of the heat flow values obtained varies as interpretation was necessary to determine geothermal gradients for many of the holes which had disturbances. A major problem in determining the heat flow values is the lack of knowledge of the in situ porosity of the rocks. The heat flow values obtained for the Eastern Snake River Plain are from shallow wells (< 200 m), hence the heat flow there is low (< 0.5 HFU) because of the water movement in the Snake Plain aquifer. The anomalous regional heat flow pattern around the Snake River Plain, together with other geophysical and geological data, suggest the presence of a major crustal heat source. With the exception of the area of the Snake Plain aquifer, high geothermal gradients were found in all areas of southern Idaho (40 to 100/sup 0/C/km). Temperatures hot enough for space heating can be found most anywhere in the Plain at relatively shallow depths (1 to 2 km). Temperatures hot enough for electrical power generation (200/sup 0/C) can be found beneath southern Idaho almost anywhere at depths of 3 to 4 kilometers. The Plain is fault bounded and hot water circulating along the fault zones from depths can be a very important geothermal resource at shallow depths. The margins of the Plain have the highest heat flow values, are the most faulted, and have possibly the highest geothermal resource potential.

Brott, C.A.; Blackwell, D.D.; Mitchell, J.C.

1976-09-01T23:59:59.000Z

94

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

95

Heat generation in natural gas adsorption systems  

SciTech Connect

Experiments were conducted using a high-surface-area carbon as an adsorbent for methane to determine the impact of the heat of adsorption upon the storage capacity. The rapid filling of an adsorption storage system under conditions in which the heat of adsorption is not dissipated results in only about 75% of the methane being stored at 3.44 MPa (500 psia) as can be stored by a slow fill rate with heat dissipation. These results depend upon the initial temperature of the absorbent bed and upon the characteristics of the substrate itself. 4 refs., 5 figs.

Remick, R.J.; Tiller, A.J.

1986-01-01T23:59:59.000Z

96

Oscillating flow loss test results in Stirling engine heat exchangers. Final Report  

SciTech Connect

The results are presented for a test program designed to generate a database of oscillating flow loss information that is applicable to Stirling engine heat exchangers. The tests were performed on heater/cooler tubes of various lengths and entrance/exit configurations, on stacked and sintered screen regenerators of various wire diameters and on Brunswick and Metex random fiber regenerators. The test results were performed over a range of oscillating flow parameters consistent with Stirling engine heat exchanger experience. The tests were performed on the Sunpower oscillating flow loss rig which is based on a variable stroke and variable frequency linear drive motor. In general, the results are presented by comparing the measured oscillating flow losses to the calculated flow losses. The calculated losses are based on the cycle integration of steady flow friction factors and entrance/exit loss coefficients.

Koester, G.; Howell, S.; Wood, G.; Miller, E.; Gedeon, D.

1990-05-01T23:59:59.000Z

97

Heat Flow At Standard Depth | Open Energy Information  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Heat Flow At Standard Depth Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat Flow At Standard Depth Details Activities (2) Areas (1) Regions (0) Abstract: Secular and long-term periodic changes in surface temperature cause perturbations to the geothermal gradient which may be significant to depths of at least 1000 m, and major corrections are required to determine absolute values of heat flow from the Earth's interior. However, detailed climatic models remain contentious and estimates of error in geothermal gradients differ widely. Consequently, regions of anomalous heat flow which

98

Guidelines on Optimizing Heat Recovery Steam Generator Drains  

Science Conference Proceedings (OSTI)

Severe thermal-mechanical fatigue damage to the superheaters (SHs), reheaters (RHs), and steam piping of horizontal-gas-path heat recovery steam generators due primarily to ineffective drainage of the condensate that is generated in superheaters and reheaters at every startup continues to be a significant industry problem that results in avoidable deterioration of unit reliability and significant unnecessary maintenance costs. This report will assist operators in guiding heat recovery steam generator (HR...

2007-12-21T23:59:59.000Z

99

Heat Recovery Steam Generator (HRSG) Chemical Cleaning Guidelines  

Science Conference Proceedings (OSTI)

Combined cycle units with heat recovery steam generators (HRSGs) represent a substantial fraction of the new fossil generating capacity installed around the world since the 1990s. One of the goals of the EPRI HRSG Dependability Program is to make availability losses due to tube failures very low, no more than one per year. An earlier guideline, "Interim Cycle Chemistry Guidelines for Combined Cycle Heat Recovery Steam Generators" (EPRI Report TR-110051), shows organizations how to set up chemistry progra...

2003-12-03T23:59:59.000Z

100

Field Guide: Heat Recovery Steam Generator Tube Failure  

Science Conference Proceedings (OSTI)

In conventional and combined-cycle plants, boiler and heat recovery steam generator (HRSG) tube failures have been the main availability problem for as long as reliable statistics have been kept for each generating source. The three volumes of the Electric Power Research Institute (EPRI) report Boiler and Heat Recovery Steam Generator Tube Failures: Theory and Practice (1012757) present an in-depth description of the various HRSG and degradation mechanisms, providing plant owners and operators with the t...

2010-12-15T23:59:59.000Z

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

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

Open Energy Info (EERE)

Heat Flow From Four New Research Drill Holes In The Western Cascades, Oregon, Usa Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat Flow From Four...

102

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

103

Flow and heat transfer in gas turbine disk cavities subject to nonuniform external pressure field  

SciTech Connect

Ingestion of hot gas from the main-stream gas path into turbine disk cavities, particularly the first-stage disk cavity, has become a serious concern for the next-generation industrial gas turbines features high rotor inlet temperature. Fluid temperature in the cavities increases further due to windage generated by fluid drag at the rotating and stationary surfaces. The resulting problem of rotor disk heat-up is exacerbated by the high disk rim temperature due to adverse (relatively flat) temperature profile of the mainstream gas in the annular flow passage of the turbine. This describes an investigation into local convective heat transfer coefficient and cooling effectiveness of the rotor disk, flow field in the disk cavity, computation of the flow field and heat transfer in the disk cavity, and mainstream gas injection and rotor disk cooling effectiveness by mass transfer analogy.

Roy, R.P.; Kim, Y.W.; Tong, T.W. [Arizona State Univ., Tempe, AZ (United States). Dept. of Mechanical and Aerospace Engineering

1995-12-31T23:59:59.000Z

104

Coevolution of inverse cascade and nonlinear heat front in shear flows of strongly coupled Yukawa liquids  

Science Conference Proceedings (OSTI)

Using classical molecular dynamics (MD) simulations, we report on the development and propagation of a nonlinear heat front in parallel shear flows of a strongly coupled Yukawa liquid. At a given coupling strength, a subsonic shear profile is superposed on an equilibrated Yukawa liquid and Kelvin Helmholtz (KH) instability is observed. Coherent vortices are seen to emerge towards the nonlinear regime of the instability. It is seen that while inverse cascade leads to a continuous transfer of flow energy towards the largest scales, there is also a simultaneous transfer of flow energy into the thermal velocities of grains at the smallest scale. The latter is an effect of velocity shear and thus leads to the generation of a nonlinear heat front. In the linear regime, the heat front is seen to propagate at speed much lesser than the adiabatic sound speed of the liquid. Spatio-temporal growth of this heat front occurs concurrently with the inverse cascade of KH modes.

Ashwin, J.; Ganesh, R. [Institute for Plasma Research, Bhat, Gandhinagar 382428, Gujarat (India)

2011-08-15T23:59:59.000Z

105

DECAY HEAT CONDITIONS OF CURRENT AND NEXT GENERATION REACTORS  

E-Print Network (OSTI)

Decay heat is an important parameter in reactor design. Fission products generate heat in the reactor core even when the reactor has shut down. This heat has potential to melt the core if heat removal is not sufficient, and it is what caused the accident in Japan last year. Thus, decay heat must be considered in reactor design for safety. The research focused on decay heat conditions of current and next generation reactors. US-APWR, ABWR, VHTR, and ABR were modeled and simulated using the program SCALE. When the reactors were simulated to operate for two years and cool down for one year, the ABR produced the most decay heat power during operation and cooling time, and the US-APWR, VHTR, and ABWR followed respectfully. Therefore, the ABR requires more coolant and cooling time than other reactors, and the ABWR requires the least.

Choe, JongSoo 1985-

2012-05-01T23:59:59.000Z

106

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

E-Print Network (OSTI)

ios in which distributed generation and heat recovery486-7976 Keywords: distributed generation; combined heat andCERTS) Microgrid. Distributed generation would alleviate the

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

2004-01-01T23:59:59.000Z

107

Distributed Generation with Heat Recovery and Storage  

E-Print Network (OSTI)

Electricity generated by distributed energy resources (DER)Energy, Office of Distributed Energy of the US Department ofdefined names including distributed energy resources (DER),

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

2005-01-01T23:59:59.000Z

108

ESS 2012 Peer Review - New Generation Aqueous Base Redox Flow...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

New Generation Aqueous Base Redox Flow Battery Component Development Wei Wang, Qingtao Luo, Xiaoliang Wei, Bin Li, Zimin Nie, Baowei Chen, Yuyan Shao, Vijayakumar Murugesan, Amy...

109

ESS 2012 Peer Review - New Generation Redox Flow Battery Prototype...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Next Generation Redox Flow Battery Prototype Development Vincent Sprenkle, Soowhan Kim, Ed Thomsen, Alasdair Crawford, Zimin Nie, Vilayanur Viswanathan, David Stephenson, Qingtao...

110

Heat Transfer Enhancement in Separated and Vortex Flows  

SciTech Connect

This document summarizes the research performance done at the Heat Transfer Laboratory of the University of Minnesota on heat transfer and energy separation in separated and vortex flow supported by DOE in the period September 1, 1998--August 31, 2003. Unsteady and complicated flow structures in separated or vortex flows are the main reason for a poor understanding of heat transfer under such conditions. The research from the University of Minnesota focused on the following important aspects of understanding such flows: (1) Heat/mass transfer from a circular cylinder; (2) study of energy separation and heat transfer in free jet flows and shear layers; and (3) study of energy separation on the surface and in the wake of a cylinder in crossflow. The current study used three different experimental setups to accomplish these goals. A wind tunnel and a liquid tunnel using water and mixtures of ethylene glycol and water, is used for the study of prandtl number effect with uniform heat flux from the circular cylinder. A high velocity air jet is used to study energy separation in free jets. A high speed wind tunnel, same as used for the first part, is utilized for energy separation effects on the surface and in the wake of the circular cylinder. The final outcome of this study is a substantial advancement in this research area.

Richard J. Goldstein

2004-05-27T23:59:59.000Z

111

Heat-flow mapping at the Geysers Geothermal Field  

SciTech Connect

Pertinent data were compiled for 187 temperature-gradient holes in the vicinity of The Geysers Geothermal field. Terrain-correction techniques were applied to most of the temperature-gradient data, and a temperature-gradient map was constructed. Cutting samples from 16, deep, production wells were analyzed for thermal conductivity. From these samples, the mean thermal conductivities were determined for serpentinized ultramafic rock, greenstone, and graywacke. Then, a heat flow map was made. The temperature-gradient and heat-flow maps show that The Geysers Geothermal field is part of a very large, northwesterly-trending, thermal anomaly; the commercially productive portion of the field may be 100 km/sup 2/ in area. The rate that heat energy flows through the surface by thermal conduction is estimated at 1.79 x 10/sup 9/MJ per year. The net heat energy loss from commercial production for 1983 is estimated at 180.14 x 10/sup 9/MJ.

Thomas, R.P.

1986-10-31T23:59:59.000Z

112

The heat transfer mechanism in aqueous foam flow in a channel  

Science Conference Proceedings (OSTI)

The Heat transfer mechanism in two-phase aqueous foam flow was investigated for developing energy-efficient heat exchangers. Such heat exchangers can provide low consumption of energy resources due to enhanced heat transfer rates. An enhanced heat transfer ... Keywords: aqueous foam flow, heat exchangers, heat transfer

Irena Gabrielaitien?; Jonas Gylys; Rolandas Jonynas; Tadas Ždankus

2011-12-01T23:59:59.000Z

113

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

DOE Green Energy (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

114

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

115

Assessment of turbine generator technology for district heating applications  

SciTech Connect

Steam turbines for cogeneration plants may carry a combination of industrial, space heating, cooling and domestic hot water loads. These loads are hourly, weekly, and seasonally irregular and require turbines of special design to meet the load duration curve, while generating electric power. Design features and performance characteristics of large cogeneration turbine units for combined electric generation and district heat supply are presented. Different modes of operation of the cogeneration turbine under variable load conditions are discussed in conjunction with a heat load duration curve for urban heat supply. The performance of the 250 MW district heating turbine as applied to meet the heat load duration curve for Minneapolis--St. Paul area is analyzed, and associated fuel savings are estimated.

Oliker, I.

1978-09-01T23:59:59.000Z

116

Heat Recovery Steam Generator Materials Selection Guideline  

Science Conference Proceedings (OSTI)

Materials selection is both an art and a science. There is no single material that is the optimal choice for a given application. For example, subtle changes such as the design, fabrication, and quality control specification for a high-pressure superheater (HPSH) tube-to-header connection can alter the choice of the optimal tube material. Minor changes to the component's operating environment can also alter the materials selection choice. What was an ideal tube material in a baseloaded heat recovery stea...

2011-12-21T23:59:59.000Z

117

Field Guide: Heat Recovery Steam Generator Outage Inspection Pocket Manual  

Science Conference Proceedings (OSTI)

Heat recovery steam generators (HRSGs) pose a unique set of operational challenges, due in part to their rapid startup capabilities and high operating efficiencies. Among these challenges are the difficulty of inspection and repair, which are complicated by limited access as well as the complexity of the equipment. To help members address these challenges, the Electric Power Research Institute's (EPRI's) Heat Recovery Steam Generator Dependability program has added this field guide to its comprehensive s...

2010-12-23T23:59:59.000Z

118

Dispersed-Flow Film Boiling Heat Transfer Data near Spacer Grids in a Rod Bundle  

Science Conference Proceedings (OSTI)

Technical Paper / Radiation Effects and Their Relationship to Geological Repository / Heat Transfer and Fluid Flow

Graydon L. Yoder; Jr.; David G. Morris; Charles B. Mullins; Larry J. Ott

119

Brine flow in heated geologic salt.  

Science Conference Proceedings (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

120

Analysis of a heat exchanger-thermoelectric generator system  

DOE Green Energy (OSTI)

Analysis of a thermoelectric generator (TEG) in an ocean thermal energy conversion (OTEC) application is presented. An analytic model is developed for describing the heat exchanger-TEG interactions. This model is used to illustrate limitations of applying conventional fixed junction temperature assumptions to systems experiencing significant temperature drops across the heat exchanger surfaces. Design methods are developed for determining the thermoelectric element geometry that produces maximum output power. Results show that a heat exchanger-TEG system may deliver about 100 W/m/sup 2/ of heat exchanger surface. This compares favorably with conventional OTEC schemes.

Henderson, J.

1979-01-01T23:59:59.000Z

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

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

Open Energy Info (EERE)

and microearthquake studies, Coso Geothermal Area, China Lake, and microearthquake studies, Coso Geothermal Area, China Lake, California. Final report Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Book: Heat flow and microearthquake studies, Coso Geothermal Area, China Lake, California. Final report Details Activities (2) Areas (1) Regions (0) Abstract: The present research effort at the Coso Geothermal Area located on the China Lake Naval Weapons Center, China Lake, California, was concerned with: (1) heat flow studies and (2) microearthquake studies associated with the geothermal phenomena in the Coso Hot Springs area. The sites for ten heat flow boreholes were located primarily using the available seismic ground noise and electrical resistivity data. Difficulty was encountered in the drilling of all of the holes due to altered, porous,

122

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

Open Energy Info (EERE)

studies, Coso Geothermal Area, China Lake, California. Technical studies, Coso Geothermal Area, China Lake, California. Technical report Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Heat flow studies, Coso Geothermal Area, China Lake, California. Technical report Details Activities (1) Areas (1) Regions (0) Abstract: Heat flow studies in the Coso Geothermal Area were conducted at China Lake, California. Temperature measurements were completed in nine of the heat flow boreholes. Temperatures were measured at five meter intervals from the ground surface to the deepest five meter interval. Subsequently, temperatures were remeasured two or three times in each borehole in order to demonstrate that equilibrium thermal conditions existed. The maximum difference in temperature, at any of the five meter intervals, was 0.03 deg

123

National need for utilizing nuclear energy for process heat generation  

DOE Green Energy (OSTI)

Nuclear reactors are potential sources for generating process heat, and their applications for such use economically competitive. They help satisfy national needs by helping conserve and extend oil and natural gas resources, thus reducing energy imports and easing future international energy concerns. Several reactor types can be utilized for generating nuclear process heat; those considered here are light water reactors (LWRs), heavy water reactors (HWRs), gas-cooled reactors (GCRs), and liquid metal reactors (LMRs). LWRs and HWRs can generate process heat up to 280/sup 0/C, LMRs up to 540/sup 0/C, and GCRs up to 950/sup 0/C. Based on the studies considered here, the estimated process heat markets and the associated energy markets which would be supplied by the various reactor types are summarized.

Gambill, W.R.; Kasten, P.R.

1984-01-01T23:59:59.000Z

124

Development of Raman Spectroscopy for a Steam Generator Heated Crevice  

Science Conference Proceedings (OSTI)

The crevice formed by the tube / tube support plate (tube/TSP) intersection in a pressurized water reactor (PWR) steam generator (SG) is a concentration site for nonvolatile impurities from steam generator water (referred to as hideout). This report describes development of a Raman spectroscopy device to investigate this chemical concentration process in situ in a simulated heated crevice.

2003-11-11T23:59:59.000Z

125

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 least 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, Monohar S. (Idaho Falls, ID); O' Brien, James E. (Idaho Falls, ID)

2004-09-14T23:59:59.000Z

126

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

127

Prediction of strongly-heated internal gas flows  

Science Conference Proceedings (OSTI)

The purposes of the present article are to remind practitioners why the usual textbook approaches may not be appropriate for treating gas flows heated from the surface with large heat fluxes and to review the successes of some recent applications of turbulence models to this case. Simulations from various turbulence models have been assessed by comparison to the measurements of internal mean velocity and temperature distributions by Shehata for turbulent, laminarizing and intermediate flows with significant gas property variation. Of about fifteen models considered, five were judged to provide adequate predictions.

McEligot, D.M. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab.]|[Univ. of Arizona, Tucson, AZ (United States)]|[Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan); Shehata, A.M. [Xerox Corp., Webster, NY (United States); Kunugi, Tomoaki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)]|[Tokai Univ., Hiratsuka, Kanagawa (Japan)

1997-12-31T23:59:59.000Z

128

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

E-Print Network (OSTI)

flow is developed based upon the second entropy for dynamical transitions between energy moment a molecular-dynamics trajectory was generated, and various time-dependent properties were accumulatedStatistical mechanical theory for steady-state systems. III. Heat flow in a Lennard-Jones fluid

Attard, Phil

129

Two-Dimensional Response of a Stably Stratified Shear Flow to Diabatic Heating  

Science Conference Proceedings (OSTI)

A two-dimensional, linearized problem in a stratified shell flow with either isolated heating or differential heating is investigated. In response to isolated heating with the heating top below the wind reversal height, the low-level vertical ...

Yuh-Lang Lin

1987-05-01T23:59:59.000Z

130

Heat transfer and fluid flow characteristics of microchannels with internal longitudinal fins.  

E-Print Network (OSTI)

??Electronic components generate large amount of heat during their operation, which requires to be dissipated. Over the past decade, internal heat generation levels have exponentially… (more)

Foong, Andrew Jun Li

2009-01-01T23:59:59.000Z

131

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

for Modeling Fluid and Heat Flow in Fractured Porous Media,with fluid and heat flow in fractured porous media arefluid and heat flow in porous media, heat pipe, reservoir simulation, fractured

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

132

Self-heating in kinematically complex magnetohydrodynamic flows  

SciTech Connect

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

Osmanov, Zaza; Rogava, Andria [Centre for Theoretical Astrophysics, ITP, Ilia State University, 0162-Tbilisi (Georgia); Poedts, Stefaan [Centre for Plasma Astrophysics, Katholieke Universiteit Leuven, Celestijnenlaan 200B, Bus 2400 B-3001 (Belgium)

2012-01-15T23:59:59.000Z

133

Modeling of fluid and heat flow in fractured geothermal reservoirs  

DOE Green Energy (OSTI)

In most geothermal reservoirs large-scale permeability is dominated by fractures, while most of the heat and fluid reserves are stored in the rock matrix. Early-time fluid production comes mostly from the readily accessible fracture volume, while reservoir behavior at later time depends upon the ease with which fluid and heat can be transferred from the rock matrix to the fractures. Methods for modeling flow in fractured porous media must be able to deal with this matrix-fracture exchange, the so-called interporosity flow. This paper reviews recent work at Lawrence Berkeley Laboratory on numerical modeling of nonisothermal multiphase flow in fractured porous media. We also give a brief summary of simulation applications to problems in geothermal production and reinjection. 29 refs., 1 fig.

Pruess, K.

1988-08-01T23:59:59.000Z

134

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  

Science Conference Proceedings (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

135

Preferential flow paths and heat pipes: Results from laboratory experiments on heat-driven flow in natural and artificial rock fractures  

SciTech Connect

Water flow in fractures under the conditions of partial saturation and thermal drive may lead to fast flow along preferential localized pathways and heat pipe conditions. Water flowing in fast pathways may ultimately contact waste packages at Yucca Mountain and transport radionuclides to the accessible environment. Sixteen experiments were conducted to visualize liquid flow in glass fracture models, a transparent epoxy fracture replica, and a rock/replica fracture assembly. Spatially resolved thermal monitoring was performed in seven of these experiments to evaluate heat-pipe formation. Depending on the fracture apertures and flow conditions, various flow regimes were observed including continuous rivulet flow for high flow rates, intermittent rivulet flow and drop flow for intermediate flow rates, and film flow for low flow rates and wide apertures. These flow regimes were present in both fracture models and in the replica of a natural fracture. Heat-pipe conditions indicated by low thermal gradients were observed in five experiments. Conditions conducive to heat-pipe formation include an evaporation zone, condensation zone, adequate space for vapor and liquid to travel, and appropriate fluid driving forces. In one of the two experiments where heat pipe conditions were not observed, adequate space for liquid-vapor counterflow was not provided. Heat pipe conditions were not established in the other, because liquid flow was inadequate to compensate for imbibition and the quantity of heat contained within the rock.

Kneafsey, T.J.; Pruess, K. [Lawrence Berkeley National Lab., CA (United States). Earth Sciences Div.

1997-06-01T23:59:59.000Z

136

An experimental study of the flow and heat transfer between enhanced heat transfer plates for PHEs  

Science Conference Proceedings (OSTI)

The flow and heat transfer between inclined discrete rib plates for plate heat exchangers have been experimentally studied. Dye injection method is used to visualize the flow structures. The visualization results show that front vortex, rear vortex and main vortex are formed between the plates. The rib parameter influence is also studied using visualization method. The pressure drop and heat transfer between the inclined discrete rib plates as well as that between inclined continuous rib plates and smooth plates are also measured. The measured results show that the inclined discrete rib plate can enhanced heat transfer 20-25% at the same pumping power compared with the commonly used inclined continuous rib plates. (author)

Li, Xiao-wei [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Meng, Ji-an; Li, Zhi-xin [School of Aerospace, Tsinghua University, Beijing 100084 (China)

2010-11-15T23:59:59.000Z

137

Compilation of EPRI Heat Recovery Steam Generator (HRSG) Guidelines  

Science Conference Proceedings (OSTI)

Combined-cycle units with heat recovery steam generators (HRSGs) represent a substantial portion of new installed generation worldwide since the 1990s. Despite being relative new, these units have experienced a significant loss of availability and reliability due to tubing failures. Many of these failures are attributed to poor design, improper operation, weaknesses in fabrication, and poor installation practices. This product is a compilation of nine (9) key individual guidelines developed to address re...

2007-12-20T23:59:59.000Z

138

Monitoring and Controlling Carryover in Heat Recovery Steam Generators  

Science Conference Proceedings (OSTI)

Optimization of the cycle chemistry in the steam generating system of combined-cycle/heat recovery steam generator (HRSG) plants is vital to ensuring the efficient and reliable operation of the equipment. Monitoring of steam purity and drum carryover are core parameters for HRSG chemistry programs. Carryover is any solid, liquid, or vaporous contaminant that leaves the HRSG steam drum along with the steam. Carryover might be the result of the limited separation of the steam/water mixture in the steam dru...

2010-10-27T23:59:59.000Z

139

Influence of Ohmic Heating on Advection-Dominated Accretion Flows  

E-Print Network (OSTI)

Advection-dominated, high-temperature, quasi-spherical accretion flow onto a compact object of mass M, recently considered by a number of authors, assume that the dissipation of turbulent energy of the flow heats the ions and that a constant fraction f of 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 unity. However, it is likely that the flows have an equipartition magnetic field with the result that dissipation of magnetic energy at a rate comparable to that for the turbulence must occur by Ohmic heating. We argue that this heating occurs as a result of plasma instabilities and that the relevant instabilities are current driven in response to the strong electric fields parallel to the magnetic field. We argue further that these instabilities heat predominantly the electrons. We analyze a model for the radial dependence of the ion and electron temperatures of a general, possibly quasi-spherical accreti...

Bisnovatyi-Kogan, G S

1997-01-01T23:59:59.000Z

140

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

SciTech Connect

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

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

Guidelines for the Nondestructive Examination of Heat Recovery Steam Generators  

Science Conference Proceedings (OSTI)

As heat recovery steam generators (HRSGs) have become more complex over the last 15 years, operating with multiple pressures and temperatures, operators have experienced an increasing suite of HRSG tube failures (HTFs). This report provides guidance on the performance of nondestructive evaluation (NDE) of HRSGs so that operators will know what types of NDE to perform and where to perform them.

2007-02-27T23:59:59.000Z

142

In-situ determination of heat flow in unconsolidated sediments  

DOE Green Energy (OSTI)

Subsurface thermal measurements are the most effective, least ambiguous tools for identifying and delineating possible geothermal resources. A technique was developed which provides reliable real-time determinations of temperature, thermal conductivity, and hence, of heat flow during the drilling operation in unconsolidated sediments. A combined temperature, gradient, and thermal conductivity experiment can be carried out, by driving a thin probe through the bit about 1.5 meters into the formation in the time that would otherwise be required for a coring trip. Two or three such experiments over the depth range of, say, 50 to 150 meters provide a high-quality heat-flow determination at costs comparable to those associated with a standard cased gradient hole to comparable depths. The hole can be backfilled and abandoned upon cessation of drilling, thereby eliminating the need for casing, grouting, or repeated site visits.

Sass, J.H.; Kennelly, J.P. Jr.; Wendt, W.E.; Moses, T.H. Jr.; Ziagos, J.P.

1979-01-01T23:59:59.000Z

143

Optical techniques for fluid flow and heat transfer  

Science Conference Proceedings (OSTI)

A review is presented of optical measuring techniques employed in momentum heat and mass transfer studies. A classification is given of those techniques that are nowadays widely employed in studies to advance the understanding of transport phenomena in fluids. Techniques that employ effects caused by fluid molecules are briefly treated, and examples of measurements are given to demonstrate the kind of information that can be obtained by these techniques. Optical techniques using tracers to obtain transport information are summarized, and laser-Doppler anemometry and its application to fluid flow studies are emphasized. Applications of this technique in single-phase and two-phase flows are given that demonstrate its potential in experimental fluid mechanics and convective heat transfer studies. 63 refs.

Durst, F. (Erlangen-Nuernberg Universitaet, Erlangen (Germany, F.R.))

1990-01-01T23:59:59.000Z

144

Conductive heat flow in the Randsburg area, California  

DOE Green Energy (OSTI)

The Randsburg known Geothermal Resource Area (KGRA) is located in a tectonically active part of the Mojave Desert just south of the Garlock Fault. To provide background information for geothermal resource appraisal, the results from five holes drilled for regional heat-flow reconnaissance (USGS, unpublished data) were combined with data from nine additional holes drilled especially as part of this study in an attempt to delineate the conductive thermal anomaly associated with observed geothermal manifestations in the Randsburg area.

Sass, J.H.; Galanis, S.P. Jr.; Marshall, B.V.; Lachenbruch, A.H.; Munroe, R.J.; Moses, T.H. Jr.

1978-01-01T23:59:59.000Z

145

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

E-Print Network (OSTI)

channels, which have applications in heat-exchangers, were studied. A finite-volume code in FORTRAN was developed to solve this problem. Modules were made for generating rids in the domain, for valving the flow velocities and pressure, for solving temperature field and for post-processing the results. For solving the flow field, colocated grid formulation was used as opposed to the staggered-grid formulation, and the SIMPLE algorithm was used to link the velocity and pressure. The line-by-line method was used to solve the algebraic equations. The geometry of the problem facilitated the application of periodic inverted symmetry boundary condition. Since this is a forced convection problem, the flow field was solved first and the converged velocity field was input to the temperature solver module. The temperature field was solved for the uniform-wall-heat-flux boundary condition. The post-processing module obtained the overall friction-factor, which is representative of the pressure drop, the local 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 Reynolds number (Re=200). Periodically fully developed flow and heat transfer in serpentine channels were salved for different geometry parameters, for different Reynolds numbers and for two different Prandtl numbers ( 0.7 and 7.0 for air and water respectively). The results were plotted to study the effect of the independent parameters on the pressure drop and the heat transfer performance. The friction factor increased as the amplitude of the serpentine channel and the Reynolds number were increased. Similar trend was observed for the heat transfer coefficients. High heat transfer coefficients are observed at certain regions in the serpentine channels which are explained by the impingement phenomena. High Prandtl number (=7.0) gives higher heat transfer coefficients than the low Pr (=0.7) because of the thinner thermal boundary layer. The enhancement of heat transfer mechanism was explained by studying the plotted flow-field velocity vectors in different planes.

Chintada, Sailesh Raju

1998-01-01T23:59:59.000Z

146

Increased use of reject heat from electric generation  

Science Conference Proceedings (OSTI)

This study aims to determine existing barriers to greater use of reject heat by electric power producers, including utilities and cogenerators. It includes analytical studies of the technical and economic issues and a survey of several electric power producers. The core analytic findings of the study are that although electric utility- based, cogenerated district heating is sometimes cost competitive with currently common furnaces and boilers, it is not clearly less expensive, and is often more expensive. Since market penetration by a new technology depends on strong perceived advantages, district heating will remain at a disadvantage unless its benefits, such as lowered emissions and decreased reliance on foreign oil, are given overt financial form through subsidies or tax incentives. The central finding from the survey was that electric utilities have arrived at the same conclusion by their own routes; we present a substantial list of their reasons for not engaging in district heating or for not pursuing it more vigorously, and many of them can be summarized as the lack of a clear cost advantage for district heat. We also note that small-scale district heating systems, based on diesel generators and located near the thermal load center, show very clear cost advantages over individual furnaces. This cost advantage is consistent with the explosive growth currently observed in private cogeneration systems.

Leigh, R.W. [Leigh (Richard W.), New York, NY (United States); Piraino, M. [Gas Research Inst., Chicago, IL (United States)

1994-02-01T23:59:59.000Z

147

Assessment of next generation nuclear plant intermediate heat exchanger design.  

DOE Green Energy (OSTI)

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

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

2008-10-17T23:59:59.000Z

148

Modeling Free Convection Flow of Liquid Hydrogen within a Cylindrical Heat Exchanger Cooled to 14 K  

E-Print Network (OSTI)

Lau, W, and Yang, S. , “A Heat Exchanger between Forced FlowWITHIN A CYLINDRICAL HEAT EXCHANGER COOLED TO 14 K S. Qof the container is a heat exchanger between the hydrogen

Yang, S.W.; Oxford U.

2004-01-01T23:59:59.000Z

149

The Influence of Proposed Repository Thermal Load on Multiphase Flow and Heat Transfer in the Unsaturated Zone of Yucca Mountain  

E-Print Network (OSTI)

22]. Fluid flow and heat-transfer processes in a two-phase,processes associated with multiphase flow and heat transferprocesses has also motivated development of fluid flow and heat transfer

Wu, Y.-S.; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, G.S.

2006-01-01T23:59:59.000Z

150

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

fluid flow and heat-transfer processes. The physicalcoupled fluid-flow and heat-transfer processes has proven toin which flow and heat transfer processes along drifts are

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

151

Estimation of heat transfer in oscillating annular flow using artifical neural networks  

Science Conference Proceedings (OSTI)

In this study, the prediction of heat transfer from a surface having constant heat flux subjected to oscillating annular flow is investigated using artificial neural networks (ANNs). An experimental study is carried out to estimate the heat transfer ... Keywords: Annular duct, Artificial neural network, Heat transfer, Oscillating flow

Unal Akdag; M. Aydin Komur; A. Feridun Ozguc

2009-09-01T23:59:59.000Z

152

Chaotic Dynamos Generated by a Turbulent Flow of Liquid Sodium  

SciTech Connect

We report the observation of several dynamical regimes of the magnetic field generated by a turbulent flow of liquid sodium (VKS experiment). Stationary dynamos, transitions to relaxation cycles or to intermittent bursts, and random field reversals occur in a fairly small range of parameters. Large scale dynamics of the magnetic field result from the interactions of a few modes. The low dimensional nature of these dynamics is not smeared out by the very strong turbulent fluctuations of the flow.

Ravelet, F.; Monchaux, R.; Aumaitre, S.; Chiffaudel, A.; Daviaud, F.; Dubrulle, B. [Service de Physique de lEtat Condense, Direction des Sciences de la Matiere, CEA-Saclay, CNRS URA 2464, 91191 Gif-sur-Yvette cedex (France); Berhanu, M.; Fauve, S.; Mordant, N.; Petrelis, F. [Laboratoire de Physique Statistique de lEcole Normale Superieure, CNRS UMR 8550, 24 Rue Lhomond, 75231 Paris Cedex 05 (France); Bourgoin, M.; Odier, Ph.; Plihon, N.; Pinton, J.-F.; Volk, R. [Laboratoire de Physique de lEcole Normale Superieure de Lyon, CNRS UMR 5672, 46 allee dItalie, 69364 Lyon Cedex 07 (France)

2008-08-15T23:59:59.000Z

153

Delivering High Reliability in Heat Recovery Steam Generators  

Science Conference Proceedings (OSTI)

Despite being relatively new, the worldwide fleet of combined-cycle units with heat recovery steam generators (HRSGs) has exhibited a disappointing record with respect to reliability and availability in terms of HRSG tube failures (HTFs). This report identifies actions that—if implemented prior to commercial operation—should greatly improve the operational HRSG reliability.BackgroundWhen contemplating new combined-cycle units, the choices that can ...

2012-12-12T23:59:59.000Z

154

A Cross-Flow Ceramic Heat Recuperator for Industrial Heat Recovery  

E-Print Network (OSTI)

With increasing fuel costs, the efficient use of fuel is very important to the U.S. process heat industries. Increase in fuel usage efficiency can be obtained by transferring the waste exhaust heat to the cold combustion air. The metallic recuperators currently available suffer from problems of creep, corrosion and oxidation, particularly at high temperatures. The Department of Energy and GTE Products corporation have pursued a jointly funded venture, Contract No. EX-76-C-Q1-2162, to establish performance criteria and demonstrate a cross-flow ceramic heat recuperator for high temperature industrial heat recovery applications. The immediate goals of the ceramic recuperator project were to demonstrate a heat exchanger capable of handling high temperatures (1600-2400oF), that is compact with a high surface area and with costs comparable to the lower temperature metal heat exchangers. This paper describes the basic GTE Products Corporation design and details the design basis, the predicted recuperator performance, the ceramic and housing materials, the recuperator design procedure and the fabrication and assembly. The data provided includes NTU-Effectiveness and low friction and heat transfer ("f" and "J") plots.

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

1980-01-01T23:59:59.000Z

155

Microscale flow visualization of nucleate boiling in small channels: Mechanisms influencing heat transfer  

SciTech Connect

This paper describes the use of a new test apparatus employing flow visualization via ultra-high-speed video and microscope optics to study microscale nucleate boiling in a small, rectangular, heated channel. The results presented are for water. Because of confinement effects produced by the channel cross section being of the same nominal size as the individual vapor bubbles nucleating at discrete wall sites, flow regimes and heat transfer mechanisms that occur in small channels are shown to be considerably different than those in large channels. Flow visualization data are presented depicting discrete bubble/bubble and bubble/wall interactions for moderate and high heat flux. Quantitative data are also presented on nucleate bubble growth behavior for a single nucleation site in the form of growth rates, bubble sizes, and frequency of generation in the presence and absence of a thin wall liquid layer. Mechanistic boiling behavior and trends are observed which support the use of this type of research as a powerful means to gain fundamental insights into why, under some conditions, nucleate boiling heat transfer coefficients are considerably larger in small channels than in large channels.

Kasza, K.E.; Didascalou, T.; Wambsganss, M.W.

1997-07-01T23:59:59.000Z

156

Characterization of Elevated Temperature Properties of Heat Exchanger and Steam Generator Alloys  

Science Conference Proceedings (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. In general dynamic strain aging is observed to begin at higher temperatures and serrated flow persists to higher temperatures in Alloy 617 compared to Alloy 800H. Dynamic strain aging is a concern for these materials since it is observed to result in reduced ductility for many solid solution alloys. The role of dynamic strain aging in the creep-fatigue behavior of Alloy 617 at temperatures of 800°C and above has also been examined in detail. Serrated flow is found to persist in cyclic stress-strain curves up to nearly the cycle to failure in some temperature and strain regimes. Results of those experiments and implications for creep-fatigue testing protocols will be described.

J.K. Wright; L.J. Carroll; J.K. Benz; J.A. Simpson; R.N. Wright; W.R. Lloyd; J.A. Chapman

2010-10-01T23:59:59.000Z

157

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

SciTech Connect

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

158

Forced flow supercritical helium in a closed heat transfer loop subjected to pulsed heat loads  

Science Conference Proceedings (OSTI)

The superconducting magnets of the tokamak JT-60SA are cooled by means of forced flows of supercritical helium at 4.4 K and 0.5 MPa. The closed loops transfer heat from the magnets to the refrigerator through heat exchangers immersed into a saturated liquid helium bath. An experimental loop was designed to represent a 1/20 scaled down mock-up of JT-60SA central solenoid cooling circuits. This design for keeping the same transit times in the helium circuits

2012-01-01T23:59:59.000Z

159

Heat flow and hot dry rock geothermal resources of the Clearlake Region, northern California  

DOE Green Energy (OSTI)

The Geysers-Clear Lake geothermal anomaly is an area of high heat flow in northern California. The anomaly is caused by abnormally high heat flows generated by asthenospheric uplift and basaltic magmatic underplating at a slabless window created by passage of the Mendocino Triple Junction. The Clear Lake volcanic field is underlain by magmatic igneous bodies in the form of a stack of sill-form intrusions with silicic bodies generally at the top and basic magmas at the bottom. The tabular shape and wide areal extent of the heat sources results in linear temperature gradients and near-horizontal isotherms in a broad region at the center of the geothermal anomaly. The Hot Dry Rock (HDR) portion of The Geysers-Clear Lake geothermal field is that part of the geothermal anomaly that is external to the steamfield, bounded by geothermal gradients of 167 mW/m2 (4 heat flow units-hfu) and 335 mW/m2 (8 hfu). The HDR resources, to a depth of 5 km, were estimated by piece-wise linear summation based on a sketch map of the heat flow. Approximately, the geothermal {open_quotes}accessible resource base{close_quotes} (Qa) is 1.68E+21 J; the {open_quotes}HDR resource base{close_quotes} (Qha) is 1.39E+21 J; and the {open_quotes}HDR power production resource{close_quotes} (Qhp) is 1.01E+21 J. The HDR power production resource (Qhp) is equivalent to 2.78E+ 11 Mwht (megawatt hours thermal), or 1.72E+11 bbls of oil.

Burns, K.L.

1996-08-01T23:59:59.000Z

160

Generation Maintenance Application Center: Combustion Turbine Combined-Cycle Heat Recovery Steam Generator Maintenance Guide  

Science Conference Proceedings (OSTI)

This guide provides information to assist personnel involved with the maintenance of the heat recovery steam generator at a combustion gas turbine combined cycle facility, including good maintenance practices, preventive maintenance techniques and troubleshooting guidance. BackgroundCombustion turbine combined cycle (CTCC) facilities utilize various components that can be unique to this particular type of power plant. As such, owners and ...

2013-05-15T23:59:59.000Z

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.


161

A unified numerical framework model for simulating flow, transport, and heat transfer in porous and fractured media  

E-Print Network (OSTI)

Flow, Transport, and Heat Transfer in Porous and Fracturedtransport, and heat transfer in porous and fracturedflow, chemical transport, and heat transfer in rock. These

Wu, Yu-Shu

2004-01-01T23:59:59.000Z

162

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

E-Print Network (OSTI)

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

Pradipta, Rezy

2012-01-01T23:59:59.000Z

163

Heating surface material’s effect on subcooled flow boiling heat transfer of R134a  

Science Conference Proceedings (OSTI)

In this study, subcooled flow boiling of R134a on copper (Cu) and stainless steel (SS) heating surfaces was experimentally investigated from both macroscopic and microscopic points of view. By utilizing a high-speed digital camera, bubble growth rate, bubble departure size, and nucleation site density, were able to be observed and analyzed from the microscopic point of view. Macroscopic characteristics of the subcooled flow boiling, such as heat transfer coefficient, were able to be measured as well. Experimental results showed that there are no obvious difference between the copper and the stainless surface with respect to bubble dynamics, such as contact angle, growth rate and departure size. On the contrary, the results clearly showed a trend that the copper surface had a better performance than the stainless steel surface in terms of heat transfer coefficient. It was also observed that wall heat fluxes on both surfaces were found highly correlated with nucleation site density, as bubble hydrodynamics are similar on these two surfaces. The difference between these two surfaces was concluded as results of different surface thermal conductivities.

Ling Zou; Barclay G. Jones

2012-11-01T23:59:59.000Z

164

Heat recovery steam generator outlet temperature control system for a combined cycle power plant  

Science Conference Proceedings (OSTI)

This patent describes a command cycle electrical power plant including: a steam turbine and at least one set comprising a gas turbine, an afterburner and a heat recovery steam generator having an attemperator for supplying from an outlet thereof to the steam turbine superheated steam under steam turbine operating conditions requiring predetermined superheated steam temperature, flow and pressure; with the gas turbine and steam turbine each generating megawatts in accordance with a plant load demand; master control means being provided for controlling the steam turbine and the heat recovery steam generator so as to establish the steam operating conditions; the combination of: first control means responsive to the gas inlet temperature of the heat recovery steam generator and to the plant load demand for controlling the firing of the afterburner; second control means responsive to the superheated steam predetermined temperature and to superheated steam temperature from the outlet for controlling the attemperator between a closed and an open position; the first and second control means being operated concurrently to maintain the superheated steam outlet temperature while controlling the load of the gas turbine independently of the steam turbine operating conditions.

Martens, A.; Myers, G.A.; McCarty, W.L.; Wescott, K.R.

1986-04-01T23:59:59.000Z

165

COMMIX analysis of the sodium heated helical coil steam generator  

SciTech Connect

This paper describes the COMMIX-HCSG computer program and compares predictions to data obtained from performance tests on a 76 MWt Helical Coil Steam Generator (HCSG) test unit. COMMIX-HCSG is a multi-dimensional thermal/hydraulic code that models both steady state and transient operation of an HCSG. The code solves a system of Navier-Stokes continuum equations that have been modified with a combination of volume and directional surface porosities and distributed resistances. This formulation properly accounts for the presence of tube bundle, supports, and baffles on the shell side of the steam generator. Turbulence models and heat transfer and pressure drop equations are used as applicable for the different regions including the upper plenum, the tube bundle, and the lower plenum of the HCSG. The data was obtained from performance tests conducted in early 1987 on the 76 MWt HCSG test unit at the Energy Technology Engineering Center (ETEC). The test unit contains over 700 instruments. HCSG development and tests are carried out as part of the Department of Energy program to develop reliable and economical liquid metal heated steam generators.

Kakarala, C.R.; Burge, S.W.; Sha, W.T.

1987-01-01T23:59:59.000Z

166

Heat-recovery steam generators: Understand the basics  

Science Conference Proceedings (OSTI)

Gas turbines with heat-recovery steam generators (HRSGs) can be found in virtually every chemical process industries (CPI) plant. They can be operated in either the cogeneration mode or the combined-cycle mode. In the cogeneration mode, steam produced from the HRSG is mainly used for process applications, whereas in the combined-cycle mode, power is generated via a steam turbine generator. Recent trends in HRSG design include multiple-pressure units for maximum energy recovery, the use of high-temperature superheaters or reheaters in combined-cycle plants, and auxiliary firing for efficient steam generation. In addition, furnace firing is often employed in small capacity units when the exhaust gas is raised to temperatures of 2,400--3,000 F to maximize steam generation and thus improve fuel utilization. This article highlights some of the basic facts about gas turbine HRSGs. This information can help plant engineers, consultants, and those planning cogeneration projects make important decisions about the system and performance related aspects.

Ganapathy, V.

1996-08-01T23:59:59.000Z

167

Salt disposal of heat-generating nuclear waste.  

SciTech Connect

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

168

Nonlinear Flow Generation By Electrostatic Turbulence In Tokamaks  

SciTech Connect

Global gyrokinetic simulations have revealed an important nonlinear flow generation process due to the residual stress produced by electrostatic turbulence of ion temperature gradient (ITG) modes and trapped electron modes (TEM). In collisionless TEM (CTEM) turbulence, nonlinear residual stress generation by both the fluctuation intensity and the intensity gradient in the presence of broken symmetry in the parallel wave number spectrum is identified for the first time. Concerning the origin of the symmetry breaking, turbulence self-generated low frequency zonal flow shear has been identified to be a key, universal mechanism in various turbulence regimes. Simulations reported here also indicate the existence of other mechanisms beyond E × B shear. The ITG turbulence driven “intrinsic” torque associated with residual stress is shown to increase close to linearly with the ion temperature gradient, in qualitative agreement with experimental observations in various devices. In CTEM dominated regimes, a net toroidal rotation is driven in the cocurrent direction by “intrinsic” torque, consistent with the experimental trend of observed intrinsic rotation. The finding of a “flow pinch” in CTEM turbulence may offer an interesting new insight into the underlying dynamics governing the radial penetration of modulated flows in perturbation experiments. Finally, simulations also reveal highly distinct phase space structures between CTEM and ITG turbulence driven momentum, energy and particle fluxes, elucidating the roles of resonant and non-resonant particles.

W.X. Wang, P.H. Diamond, T.S. Hahm, S. Ethier, G. Rewoldt, and W.M. Tang

2010-07-07T23:59:59.000Z

169

Nonlinear flow generation by electrostatic turbulence in tokamaks  

SciTech Connect

Global gyrokinetic simulations have revealed an important nonlinear flow generation process due to the residual stress produced by electrostatic turbulence of ion temperature gradient (ITG) modes and trapped electron modes (TEMs). In collisionless TEM (CTEM) turbulence, nonlinear residual stress generation by both the fluctuation intensity and the intensity gradient in the presence of broken symmetry in the parallel wavenumber spectrum is identified for the first time. Concerning the origin of the symmetry breaking, turbulence self-generated low frequency zonal flow shear has been identified to be a key, universal mechanism in various turbulence regimes. Simulations reported here also indicate the existence of other mechanisms beyond ExB shear. The ITG turbulence driven 'intrinsic' torque associated with residual stress is shown to increase close to linearly with the ion temperature gradient, in qualitative agreement with experimental observations in various devices. In CTEM dominated regimes, a net toroidal rotation is driven in the cocurrent direction by intrinsic torque, consistent with the experimental trend of observed intrinsic rotation. The finding of a 'flow pinch' in CTEM turbulence may offer an interesting new insight into the underlying dynamics governing the radial penetration of modulated flows in perturbation experiments. Finally, simulations also reveal highly distinct phase space structures between CTEM and ITG turbulence driven momentum, energy, and particle fluxes, elucidating the roles of resonant and non-resonant particles.

Wang, W. X.; Hahm, T. S.; Ethier, S.; Rewoldt, G.; Tang, W. M. [Plasma Physics Laboratory, Princeton University, P.O. Box 451, Princeton, New Jersey 08543 (United States); Diamond, P. H. [University of California, San Diego, La Jolla, California 92093 (United States)

2010-07-15T23:59:59.000Z

170

PERFORMANCE OF A SINGLE-ROW HEAT EXCHANGER AT LOW IN-TUBE FLOW RATES  

E-Print Network (OSTI)

PERFORMANCE OF A SINGLE-ROW HEAT EXCHANGER AT LOW IN-TUBE FLOW RATES A Thesis Submitted April 1995 #12;PERFORMANCE OF A SINGLE-ROW HEAT EXCHANGER AT LOW IN-TUBE FLOW RATES by Xiangwei Zhao Abstract The steady and time-dependentbehavior of a single-row heat exchanger with water and air in the in

Sen, Mihir

171

Artificial neural network control of a heat exchanger in a closed flow air circuit  

Science Conference Proceedings (OSTI)

This paper experimentally investigates the control of a heat exchanger in a closed flow air circuit. The temperature inside the test section of the test facility has been maintained at a set value by variation of air flow rate over the heat exchanger ... Keywords: Air circuit, Heat exchanger, Multi-layer perceptron, Neural network control, PID control

Kapil Varshney; P. K. Panigrahi

2005-07-01T23:59:59.000Z

172

On Water Flow in Hot Fractured Rock -- A Sensitivity Study on the Impact of Fracture-Matrix Heat Transfer  

E-Print Network (OSTI)

of multiphase, multicomponent fluid mixtures in porous andmultiphase heat and mass flow in unsaturated fractured porous

Birkholzer, Jens T.; Zhang, Yingqi

2005-01-01T23:59:59.000Z

173

Heat flow in relation to hydrothermal activity in the southern Black Rock Desert, Nevada  

DOE Green Energy (OSTI)

As part of an investigation of the Gerlach NE KGRA (Known Geothermal Resource Area) a number of heat-flow measurements were made in playa sediments of the southern Black Rock Desert, northwestern Nevada. These data together with additional previously unpublished heat-flow values reveal a complex pattern of heat flow with values ranging between 1.0 to 5.0 HFU (40 to 100 mWm/sup -2/) outside of the hot springs area. The mean heat flow for the 13 reported sites in the southern Black Rock Desert is 1.8 +- 0.15 HFU (75 +- 6 mWm/sup -2/). The complexity of the pattern of heat flow is believed to arise from hydrothermal circulation supporting the numerous hot springs throughout the region. The fact that the lowest observed heat flow occurs in the deepest part of the basin strongly suggests that fluid movement within the basin represents part of the recharge for the hydrothermal system. A thermal balance for the system incorporating both anomalous conductive heat loss and convective heat loss from the spring systems indicate a total energy loss of about 8.0 Mcal/sec or 34 megawatts over an estimated 1000 km/sup 2/ region. Consideration of this additional heat loss yields a mean regional heat flow of 2.5 + HFU (100 + mWm/sup -2/) and warrants inclusion of this region in the Battle Mountain heat-flow high (Lachenbruch and Sass, 1977, 1978).

Sass, J.H.; Zoback, M.L.; Galanis, S.P. Jr.

1979-01-01T23:59:59.000Z

174

Flow over Heated Terrain. Part I: Linear Theory and Idealized Numerical Simulations  

Science Conference Proceedings (OSTI)

The flow past heated topography is examined with both linear and nonlinear models. It is first shown that the forcing of an obstacle with horizontally homogenous surface heating can be approximated by the forcing of an obstacle with surface ...

N. Andrew Crook; Donna F. Tucker

2005-09-01T23:59:59.000Z

175

A Variable Refrigerant Flow Heat Pump Computer Model in EnergyPlus  

SciTech Connect

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

176

Heat Flow Database Expansion for NGDS Data Development, Collection and  

Open Energy Info (EERE)

Database Expansion for NGDS Data Development, Collection and Database Expansion for NGDS Data Development, Collection and Maintenance Geothermal Project Jump to: navigation, search Last modified on July 22, 2011. Project Title Heat Flow Database Expansion for NGDS Data Development, Collection and Maintenance Project Type / Topic 1 Recovery Act: Geothermal Technologies Program Project Type / Topic 2 Geothermal Data Development, Collection, and Maintenance Project Description In particular the efforts on document and core digitization, the recovery of the BEG geopressure data developed during the approximately $200 million project by DOE in the 1970-1980, the EGS data from the Fenton Hill experiments, and meta-data associated with US thermal mapping are crucial to be performed at this point because they are otherwise in danger of deterioration or complete loss.

177

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

Science Conference Proceedings (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

178

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

Open Energy Info (EERE)

repository. The modeling approach is based on a mathematical formulation of coupled multiphase, multicomponent fluid and heat flow through porous and fractured rock. Fracture...

179

Continuous flow microwave heating : evaluation of system efficiency and enzyme inactivation kinetics.  

E-Print Network (OSTI)

??A continuous flow microwave heating system was set up by using one domestic microwave oven (1000W nominal output at 2450MHz). Water was run through the… (more)

Lin, Man Guang, 1966-

2004-01-01T23:59:59.000Z

180

Flow fields and heat transfer of liquid falling film on horizontal cylinders.  

E-Print Network (OSTI)

??A liquid film flowing over horizontal cylinders is of great importance as a high rate of heat transfer exists between the falling liquid film and… (more)

Jafar, Farial A

2011-01-01T23:59:59.000Z

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

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… (more)

Westheimer, David Thomas

2012-01-01T23:59:59.000Z

182

Simulation and performance analysis of an ammonia-water absorption heat pump based on the generator-absorber heat exchange (GAX) cycle  

Science Conference Proceedings (OSTI)

A computer simulation has been conducted to investigate the performance of an absorption heat pump, based on the Generator-Absorber Heat Exchange (GAX) cycle employing ammonia-water as the working fluid pair. The particular feature of this cycle is the ability to recover heat from the absorber and employ it to partially heat the generator, thus improving the COP. In the present study, a detailed simulation has been conducted of one of the preferred configurations for the cycle. A modular computer code for flexible simulation of absorption systems (ABSIM) was employed. Performance parameters, including COP and capacity, were investigated as functions of different operating parameters over a wide range of conditions in both the cooling and heating mode. The effect of the ambient temperature, the rectifier performance, the flowrate in the GAX heat transfer loop and the refrigerant flow control were investigated. COP`s on the order of 1.0 for cooling and 2.0 for heating have been calculated.

Grossman, G. [Israel Institute of Technology, Haifa (Israel); DeVault, R.C.; Creswick, F.A. [Oak Ridge National Lab., TN (United States)

1995-02-01T23:59:59.000Z

183

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

Open Energy Info (EERE)

From Four New Research Drill Holes In The Western Cascades, From Four New Research Drill Holes In The Western Cascades, Oregon, Usa Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat Flow From Four New Research Drill Holes In The Western Cascades, Oregon, Usa Details Activities (1) Areas (1) Regions (0) Abstract: Conceptual models of the thermal structure of the Oregon Cascade Range propose either (1) a narrow zone of magmatic heat sources, flanked by shallow heat-flow anomalies caused by lateral ground-water flow; or (2) a wide zone of magmatic heat sources, with localized, generally negligible ground-water effects. The proposed narrow heat source coincides with the Quaternary volcanic arc, whereas the wider heat source would extend 10-30 km west of the arc. To test the models, four new heat-flow holes were sited

184

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

heat flow in porous media, heat pipe, reservoir simulation,and vapor often leads to “heat-pipe” conditions, the steadytwo-phase zone, is the heat-pipe (i.e. , a zone of constant

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

185

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

SciTech Connect

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

186

Induced draft fan innovation for heat recovery steam generators  

SciTech Connect

A first of its kind, induced draft (ID) heat recovery steam generators (HRSG) have been in service at a cogeneration facility since 1991. A preliminary engineering study considered a forced draft (FD) fan to supply combustion air to the HRSG duct burners (when the combustion turbine (CT) is out of service) as a traditional design; however, the study indicated that the FD fan may require the HRSG duct burner to be shut off following a CT trip and re-ignited after the FD fan was in service. Although the induced draft HRSG design cost more than the FD fan design, the induced draft design has improved the cogeneration facility's steam generation reliability by enabling the HRSG to remain in service following a CT trip. This paper briefly summarizes the preliminary engineering study that supported the decision to select the ID fan design. The paper also discusses the control system that operates the fresh-air louvers, duct burners, HRSG, and ID fan during a CT trip. Startup and operating experiences are presented that demonstrate the effectiveness of the design. Lessons learned are also summarized for input into future induced draft HRSG designs.

Beasley, O.W.; Hutchins, E.C. (Oklahoma Gas and Electric Co., Oklahoma City, OK (United States)); Predick, P.R.; Vavrek, J.M. (Sargent and Lundy, Chicago, IL (United States))

1994-04-01T23:59:59.000Z

187

Automatic ID heat load generation in ANSYS code  

SciTech Connect

Detailed power density profiles are critical in the execution of a thermal analysis using a finite element (FE) code such as ANSYS. Unfortunately, as yet there is no easy way to directly input the precise power profiles into ANSYS. A straight-forward way to do this is to hand-calculate the power of each node or element and then type the data into the code. Every time a change is made to the FE model, the data must be recalculated and reentered. One way to solve this problem is to generate a set of discrete data, using another code such as PHOTON2, and curve-fit the data. Using curve-fitted formulae has several disadvantages. It is time consuming because of the need to run a second code for generation of the data, curve-fitting, and doing the data check, etc. Additionally, because there is no generality for different beamlines or different parameters, the above work must be repeated for each case. And, errors in the power profiles due to curve-fitting result in errors in the analysis. To solve the problem once and for all and with the capability to apply to any insertion device (ID), a program for ED power profile was written in ANSYS Parametric Design Language (APDL). This program is implemented as an ANSYS command with input parameters of peak magnetic field, deflection parameter, length of ID, and distance from the source. Once the command is issued, all the heat load will be automatically generated by the code.

Wang, Zhibi

1992-04-30T23:59:59.000Z

188

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

SciTech Connect

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

189

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

Science Conference Proceedings (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

190

Flow over Heated Terrain. Part II: Generation of Convective Precipitation  

Science Conference Proceedings (OSTI)

Previous studies have shown that thunderstorms in the Rocky Mountain region have preferred areas in which to form. There has been some indication that these areas depend on the midtropospheric wind direction. A nonhydrostatic model with a terrain-...

Donna F. Tucker; N. Andrew Crook

2005-09-01T23:59:59.000Z

191

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

192

Geothermal Resource-Reservoir Investigations Based On Heat Flow And Thermal  

Open Energy Info (EERE)

Resource-Reservoir Investigations Based On Heat Flow And Thermal Resource-Reservoir Investigations Based On Heat Flow And Thermal Gradient Data For The United States Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Geothermal Resource-Reservoir Investigations Based On Heat Flow And Thermal Gradient Data For The United States Details Activities (2) Areas (2) Regions (0) Abstract: 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

193

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

Open Energy Info (EERE)

in the northern Basin and Range province in the northern Basin and Range province Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Heat flow in the northern Basin and Range province Abstract The heat flow in the Basin and Range province of northern Nevada is extremely complex. It is a product of superposition of the regional effects of extension and volcanism /intrusion modified by the local conductive effects of thermal refraction (complicated structural settings),variations in radioactive heat production, erosion and sedimentation. In addition to these conductive effects,groundwater flow, both on a local and a regional basis,affects heat-flow measurements. Typical heat -flow values for the Basin and Range province average 85 +/- 10 mWm-2. The higher estimates are

194

A Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca  

Open Energy Info (EERE)

Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca Mountain, Nevada Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca Mountain, Nevada Details Activities (0) Areas (0) Regions (0) Abstract: A three-dimensional unsaturated-zone numerical model has been developed to simulate flow and distribution of moisture, gas and heat at Yucca Mountain, Nevada, a potential repository site for high-level radioactive waste. The model takes into account the simultaneous flow dynamics of liquid water, vapor, air and heat in the highly heterogeneous, fractured porous rock in the unsaturated zone (UZ). This model is intended for use in the prediction of the current and future conditions in the UZ so

195

Self-Generated Magnetic Fields in Galactic Cooling Flows  

E-Print Network (OSTI)

Interstellar magnetic fields in elliptical galaxies are assumed to have their origin in stellar fields that accompany normal mass loss from an evolving population of old stars. The seed fields are amplified by interstellar turbulence driven by stellar mass loss and supernova events. These disordered fields are further amplified by time-dependent compression in the inward moving galactic cooling flow and are expected to dominate near the galactic core. Under favorable circumstances, fields similar in strength to those observed $B \\sim 1-10~(r/10~kpc)^{-1.2}\\mu$G can be generated solely from these natural galactic processes. In general the interstellar field throughout elliptical galaxies is determined by the outermost regions in the interstellar gas where the turbulent dynamo process can occur. Because of the long hydrodynamic flow times in galactic cooling flows, currently observed magnetic fields may result from periods of intense turbulent field amplification that occurred in the outer galaxy in the distant past. Particularly strong fields in ellipticals may result from ancient galactic mergers or shear turbulence introduced at the boundary between the interstellar gas and ambient cluster gas.

William G. Mathews; Fabrizio Brighenti

1997-06-10T23:59:59.000Z

196

Temperature-gradient and heat flow data, Grass Valley, Nevada  

DOE Green Energy (OSTI)

A series of 16 shallow and intermediate-depth temperature-gradient holes were drilled for Sunoco Energy Development Co. in Grass Valley, Pershing County, Nevada, on leases held by Aminoil USA, Inc., under the cost-sharing industry-linked program of the Department of Energy. Thirteen shallow (85-152 m) and 3 intermediate-depth (360-457 m) holes were completed and logged during the period June through September, 1979. The locations of these holes and of pre-existing temperature-gradient holes are shown on plate 1. This report constitutes a final data transmittal and disclosure of results. The drilling subcontractor was Southwest Drilling and Exploration, Inc. of Central, Utah. They provided a Gardner-Denver 15W rig, a 3-man crew, and supporting equipment. A l l holes were drilled with mud as the circulating medium. Drilling histories for each hole are summarized in table 1. GeothermEx, Inc. performed on-site geological descriptions of the cuttings; obtained several temperature profiles for each hole, including an equilibrium profile taken 23 days or more after cessation of drilling; selected samples for thermal conductivity measurements; integrated temperature, temperature-gradient, and heat-flow data obtained in this project with published values; and prepared this report.

Koenig, James B.; Gardner, Murray C.

1979-11-01T23:59:59.000Z

197

New heat-flow contour map of the conterminous United States  

DOE Green Energy (OSTI)

A series of maps is presented, depicting the heat flow within the conterminous United States based on all data available to the U.S. Geological Survey (USGS) as of August 1976. Sources include all published data and about a hundred new USGS values currently being readied for publication. Tables are included on locations, heat flow, and heat production for published values plotted on the maps. (JGB)

Sass, J.H.; Diment, W.H.; Lachenbruch, A.H.; Marshall, B.V.; Munroe, R.J.; Moses, T.H. Jr.; Urban, T.C.

1976-01-01T23:59:59.000Z

198

Numerical simulation of fluid flow and heat transfer in a water heater  

Science Conference Proceedings (OSTI)

Energy consumption represents a major concern, considering the limited resources and latest targets for lower emissions of carbon dioxide. Therefore design of electric heating elements for household and industry are more and more subject to optimization, ... Keywords: electric heating, finite elements, fluid flow, heat transfer

Mircea Nicoar?; Aurel R?du??; Lauren?iu Roland Cucuruz; Cosmin Locovei

2010-04-01T23:59:59.000Z

199

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

grain-specific heat for each model grid layer, are providedand heat flow is simulated using the 3-D TH model grid (

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

200

On the Wave Spectrum Generated by Tropical Heating  

Science Conference Proceedings (OSTI)

Convective heating profiles are computed from one month of rainfall rate and cloud-top height measurements using global Tropical Rainfall Measuring Mission and infrared cloud-top products. Estimates of the tropical wave response to this heating ...

David A. Ortland; M. Joan Alexander; Alison W. Grimsdell

2011-09-01T23:59:59.000Z

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.


201

Milliwatt generator heat source. Quarterly technical progress report, April 16, 1976--July 15, 1976  

Science Conference Proceedings (OSTI)

Activities at MRC associated with the Milliwatt Generator Heat Source efforts over the period April 16, 1976, to July 15, 1976, are presented below.

Amos, W.R.

1996-07-01T23:59:59.000Z

202

Integration of Combined Heat and Power Generators into Small Buildings - A Transient Analysis Approach.  

E-Print Network (OSTI)

??Small combined heat and power generators have the potential to reduce energy consumption and greenhouse gas emissions of residential buildings. Recently, much attention has been… (more)

DeBruyn, Adrian Bryan

2007-01-01T23:59:59.000Z

203

Vibration Induced Droplet Generation from a Liquid Layer for Evaporative Cooling in a Heat Transfer Cell .  

E-Print Network (OSTI)

??During this investigation, vibration induced droplet generation from a liquid layer was examined as a means for achieving high heat flux evaporative cooling. Experiments were… (more)

Pyrtle, Frank, III

2005-01-01T23:59:59.000Z

204

The Study of Heat and Mass Transfer In The Generator For an Absorption Air Conditioning System.  

E-Print Network (OSTI)

??This thesis is aimed to study the heat and mass transfer performance of a generator for the absorption cooling system. Both aqueous lithium bromide (LiBr)… (more)

Hsu, Yu-lien

2012-01-01T23:59:59.000Z

205

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

206

Analysis on electro-thermal property of micro-bubble generator using carbon nanotube heating elements  

Science Conference Proceedings (OSTI)

Localized high temperature due to Joule heating in Carbon Nanotubes (CNTs) can generate micron-sized bubbles. Electro-thermal property of CNTs-based microbubble generator is characterized by finite element analysis in this paper. Water circumstance with ...

Wenli Zhou; Sanping Wan; Chao Zhu

2009-01-01T23:59:59.000Z

207

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

DOE Green Energy (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

208

Flow and heat transfer in a curved pipe with periodically varying curvature  

SciTech Connect

A numerical analysis is carried out for the study of the flow and heat transfer for a laminar flow in a pipe with periodically varying finite (not very small) curvature. The effects of the flow rate (Re), the Prandtl number (Pr), the pipe-period ({kappa}) and the pipe-amplitude (a) on the heat transfer ratio (heat transfer of curved pipe to straight pipe) are studied. The results show that an increase in the amplitude and/or a decrease in the wavelength of a periodic wavy pipe can enhance the heat transfer rate significantly. The ratio of the heat transfer ratio to the friction ratio is greater than one which means a net benefit of heat transfer enhancement.

Yang, R.; Chang, S.F.; Wu, W.

2000-01-01T23:59:59.000Z

209

Cooling by Heat Conduction Inside Magnetic Flux Loops and the Moderate Cluster Cooling Flow Model  

E-Print Network (OSTI)

I study non-radiative cooling of X-ray emitting gas via heat conduction along magnetic field lines inside magnetic flux loops in cooling flow clusters of galaxies. I find that such heat conduction can reduce the fraction of energy radiated in the X-ray band by a factor of 1.5-2. This non-radiative cooling joins two other proposed non-radiative cooling processes, which can be more efficient. These are mixing of cold and hot gas, and heat conduction initiated by magnetic fields reconnection between hot and cold gas. These processes when incorporated into the moderate cooling flow model lead to a general cooling flow model with the following ingredients. (1) Cooling flow does occur, but with a mass cooling rate about 10 times lower than in old versions of the cooling flow model. Namely, heating occurs such that the effective age of the cooling flow is much below the cluster age, but the heating can't prevent cooling altogether. (2) The cooling flow region is in a non-steady state evolution. (3) Non-radiative cooling of X-ray emitting gas can bring the model to a much better agreement with observations. (4) The general behavior of the cooling flow gas, and in particular the role played by magnetic fields, make the intracluster medium in cooling flow clusters similar in some aspects to the active solar corona.

Noam Soker

2003-11-02T23:59:59.000Z

210

Combined cycle electric power plant and heat recovery steam generator having improved multi-loop temperature control of the steam generated  

SciTech Connect

A combined cycle electric power plant is described that includes gas and steam turbines and a steam generator for recovering the heat in the exhaust gases exited from the gas turbine and for using the recovered heat to produce and supply steam to the steam turbine. The steam generator includes a superheater tube and a steam drum from which heated steam is directed through the superheater to be additionally heated into superheated steam by the exhaust gas turbine gases. An afterburner serves to further heat the exhaust gas turbine gases passed to the superheater tube and a bypass conduit is disposed about the superheater tube whereby a variable steam flow determined by a bypass valve disposed in the bypass conduit may be directed about the superheater tube to be mixed with the superheated steam therefrom, whereby the temperature of the superheated steam supplied to the steam turbine may be accurately controlled. Steam temperature control means includes a first control loop responsive to the superheated steam temperature for regulating the position of the bypass valve with respect to a first setpoint, and a second control loop responsive to the superheated steam temperature for controlling the fuel supply to the afterburner with respect to a second setpoint varying in accordance with the bypass valve position. In particular, as the bypass valve position increases, the second setpoint, originally higher, is lowered toward a value substantially equal to that of the first setpoint.

Martz, L.F.; Plotnick, R.J.

1976-08-17T23:59:59.000Z

211

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

212

A unified numerical framework model for simulating flow, transport, and heat transfer in porous and fractured media  

E-Print Network (OSTI)

fluid flow, multicomponent transport, and heat transfer in porous and fractured media,fluid flow, solute transport, and heat transfer occur in porous and fractured media.fluid flow, mass transport, and heat-transfer processes through porous and fractured media.

Wu, Yu-Shu

2004-01-01T23:59:59.000Z

213

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

SciTech Connect

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

214

Stirling engines in generating heat and electricity for micro: CHP systems  

Science Conference Proceedings (OSTI)

In this paper, an analysis of different generating heat and electricity systems with Stirling engine is made from the point of view of benefits and limitations, both operational and economic and environmental. Stirling engine has the ability to work ... Keywords: biomass, fossil fuels, generating heat and electricity system, m-CHP, stirling engine

Dan Scarpete; Krisztina Uzuneanu

2011-03-01T23:59:59.000Z

215

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

E-Print Network (OSTI)

Intercalation-Induced Stress and Heat Generation within Single Lithium-Ion Battery Cathode sur- faces in postmortem analysis of batteries.5-7 Stress generation results from lithium-ion, as will be discussed later. Heat transfer analyses of lithium-ion batteries have stemmed from work on full cells.10

Sastry, Ann Marie

216

Prediction of the Effect of Heat Generation in Ballscrew on the Accuracy of CNC Milling Machine  

Science Conference Proceedings (OSTI)

In high speed machining, friction between the moving parts, generates heat. One of the major causes of thermal errors in linear axes is the heat generated in ball screw during operation at high speed. Thermal errors affect the accuracy of the linear ... Keywords: CNC Milling Machine, Ballscrew, Circular Deviations, Ballbar Test, Artificial neural network

Hojat Dehnavi; Mohammad Reza Movahhedy; Ahmad Naebi; Soleyman Pasban

2012-03-01T23:59:59.000Z

217

Two-phase gas-liquid flow characteristics inside a plate heat exchanger  

Science Conference Proceedings (OSTI)

In the present study, the air-water two-phase flow characteristics including flow pattern and pressure drop inside a plate heat exchanger are experimentally investigated. A plate heat exchanger with single pass under the condition of counter flow is operated for the experiment. Three stainless steel commercial plates with a corrugated sinusoidal shape of unsymmetrical chevron angles of 55 and 10 are utilized for the pressure drop measurement. A transparent plate having the same configuration as the stainless steel plates is cast and used as a cover plate in order to observe the flow pattern inside the plate heat exchanger. The air-water mixture flow which is used as a cold stream is tested in vertical downward and upward flow. The results from the present experiment show that the annular-liquid bridge flow pattern appeared in both upward and downward flows. However, the bubbly flow pattern and the slug flow pattern are only found in upward flow and downward flow, respectively. The variation of the water and air velocity has a significant effect on the two-phase pressure drop. Based on the present data, a two-phase multiplier correlation is proposed for practical application. (author)

Nilpueng, Kitti [Department of Mechanical Engineering, South East Asia University, Bangkok 10160 (Thailand); 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)

2010-11-15T23:59:59.000Z

218

Flow and heat transfer due to a buoyant ceiling jet turning downward at a corner  

Science Conference Proceedings (OSTI)

An experimental investigation has been carried out on the flow and heat transfer characteristics of a horizontal buoyant ceiling jet that turns downward at a corner to yield a vertical negatively buoyant wall flow. In this study, a two-dimensional jet of heated air is discharged adjacent to the lower surface of an isothermal horizontal plate. An isothermal vertical plate is attached at the other end of the horizontal surface, making a right angle corner. The vertical penetration distance of the resulting downward flow is measured and is related to the inflow conditions, particularly to the temperature and velocity at the jet discharge. This penetration distance is found to increase as the distance between the discharge location and the corner is reduced and also as the relative buoyancy level in the inlet flow is decreased. Velocity and temperature measurements are also carried out over the flow region. These indicate that the ceiling flow separates from the horizontal surface just before reaching the corner and then reattaches itself to the vertical wall at a finite distance vertically below the corner. The local surface heat flux measurements show a minimum in the heat transfer rate before the turn, along with a recovery in the heat transfer rate after the turn and the existence of a small recirculation zone near the corner. The net entrainment into the flow and heat transfer rate to the solid boundaries are also measured and correlated with the jet discharge conditions. 22 refs., 12 figs., 1 tab.

Kapoor, K.; Jaluria, Y. [Rutgers - State Univ. of New Jersey, New Brunswick, NJ (United States)

1996-02-01T23:59:59.000Z

219

Establishing the Technical Basis for Disposal of Heat-generating Waste in  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Establishing the Technical Basis for Disposal of Heat-generating Establishing the Technical Basis for Disposal of Heat-generating Waste in Salt Establishing the Technical Basis for Disposal of Heat-generating Waste in Salt The report summarizes available historic tests and the developed technical basis for disposal of heat-generating waste in salt, and the means by which a safety case for disposal of heat generating waste at a generic salt site can be initiated from the existing technical basis. Though the basis for a salt safety case is strong and has been made by the German repository program, RD&D programs continue in order to help reduce uncertainty, to improve understanding of certain complex processes, to demonstrate operational concepts, to confirm performance expectations, and to improve modeling capabilities utilizing the latest software platforms.

220

The simplicity of fractal-like flow networks for effective heat and mass transport  

SciTech Connect

A variety of applications using disk-shaped fractal-like flow networks and the status of one and two-dimensional predictive models for these applications are summarized. Applications discussed include single-phase and two-phase heat sinks and heat exchangers, two-phase flow separators, desorbers, and passive micromixers. Advantages of using these fractal-like flow networks versus parallel-flow networks include lower pressure drop, lower maximum wall temperature, inlet plenum symmetry, alternate flow paths, and pressure recovery at the bifurcation. The compact nature of microscale fractal-like branching heat exchangers makes them ideal for modularity. Differences between fractal-like and constructal approaches applied to disk-shaped heat sink designs are highlighted, and the importance of including geometric constraints, including fabrication constraints, in flow network design optimization is discussed. Finally, a simple pencil and paper procedure for designing single-phase heat sinks with fractal-like flow networks based solely on geometric constraints is outlined. Benefit-to-cost ratios resulting from geometric-based designs are compared with those from flow networks determined using multivariable optimization. Results from the two network designs are within 11%. (author)

Pence, Deborah [Oregon State University, Mechanical Engineering, 204 Rogers Hall, Corvallis, Oregon 97331-6001 (United States)

2010-05-15T23:59:59.000Z

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

Variational formulations for resting irreversible fluids with heat flow  

Science Conference Proceedings (OSTI)

Nonequilibrium statistical mechanics helps to estimate corrections to the entropy and energy of the fluid with heat flux in terms of the nonequilibrium distribution function, f. This leads to the coefficients of wave model of heat: relaxation ... Keywords: conservation laws, entropy, grad solution, variational calculus, wave equations

Stanislaw Sieniutycz; Piotr Kuran

2008-09-01T23:59:59.000Z

222

Enhanced Heat Flow in the Hydrodynamic Collisionless Regime  

SciTech Connect

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

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

2009-08-28T23:59:59.000Z

223

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

Open Energy Info (EERE)

And Geothermal Potential In The South-Central United States And Geothermal Potential In The South-Central United States Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat Flow And Geothermal Potential In The South-Central United States Details Activities (1) Areas (1) Regions (0) Abstract: Geothermal exploration is typically limited to high-grade hydrothermal reservoirs that are usually found in the western United States, yet large areas with subsurface temperatures above 150 deg. C at economic drilling depths can be found east of the Rocky Mountains. The object of this paper is to present new heat flow data and to evaluate the geothermal potential of Texas and adjacent areas. The new data show that, west of the Ouachita Thrust Belt, the heat flow values are lower than east of the fault zone. Basement heat flow values for the Palo Duro and Fort

224

Temperatures, heat flow, and water chemistry from drill holes in the Raft  

Open Energy Info (EERE)

Temperatures, heat flow, and water chemistry from drill holes in the Raft Temperatures, heat flow, and water chemistry from drill holes in the Raft River geothermal system, Cassia County, Idaho Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Temperatures, heat flow, and water chemistry from drill holes in the Raft River geothermal system, Cassia County, Idaho Details Activities (1) Areas (1) Regions (0) Abstract: The Raft River area of Idaho contains a geothermal system of intermediate temperatures (approx. = 150 0C) at depths of about 1.5 km. Outside of the geothermal area, temperature measurements in three intermediate-depth drill holes (200 to 400 m) and one deep well (1500 m) indicate that the regional conductive heat flow is about 2.5 mucal/cm 2 sec or slightly higher and that temperature gradients range from 50 0 to 60

225

Analysis of Chemically Reacting Gas Flow and Heat Transfer in Methane Reforming Processes  

Science Conference Proceedings (OSTI)

This paper presents simulation and analysis of gas flow and heat transfer affected by chemical reactions relating to steam reforming of methane in a compact reformer. The reformer conditions such as the combined thermal boundary conditions on solid walls, ...

Guogang Yang; Danting Yue; Xinrong Lv; Jinliang Yuan

2009-10-01T23:59:59.000Z

226

Three-Dimensional Response of a Shear Flow to Elevated Heating  

Science Conference Proceedings (OSTI)

The three-dimensional response of a shear flow to elevated heating is investigated using linear theory. The basic wind profile is allowed to reverse directions at a certain height. Effects of shear, evaporative cooling, and the stratosphere are ...

Yuh-Lang Lin; Shiaolin Li

1988-10-01T23:59:59.000Z

227

A Blow-up Criterion for Two Dimensional Compressible Viscous Heat-Conductive Flows  

E-Print Network (OSTI)

We establish a blow-up criterion in terms of the upper bound of the density and temperature for the strong solution to 2D compressible viscous heat-conductive flows. The initial vacuum is allowed.

Fang, Daoyuan; Zhang, Ting

2011-01-01T23:59:59.000Z

228

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

229

Continental margin subsidence and heat flow: important parameters in formation of petroleum hydrocarbons  

Science Conference Proceedings (OSTI)

Passive continental margins have been shown to subside with a 50-My exponentially decaying rate which cannot be explained by isostatic compensation for sediment loading. This suggests that the subsidence is dominated by geodynamic processes similar to those in the deep ocean. Two simple geologic models for continental breakup are developed: (1) attenuation of continental lithosphere; and (2) intrusion of mantle diapirs. These models for rifting give a direct relation between subsidence of passive margins and their surface heat flow through time. On this basis we develop a method of reconstructing the thermal history of sedimentary strata from regional subsidence and sedimentation history. Because generation of petroleum hydrocarbons depends on the intergrated time/temperature history of buried organic material, this reconstruction technique can be used to determine the depth to the oil range of the hydrocarbon generation window in advance of drilling. By way of example, we reconstruct time/temperature/depth plots and estimate hydrocarbon maturity for one site in the Falkland Plateau and three sites in the North Atlantic near Cape Hatteras. In addition to providing a method for evaluating hydrocarbon potential in frontier regions where there is little or no well control, this approach suggests that there may be significant potential for oil and gas generation on the outer part of the continental rise and in deep-sea sedimentary basins. 13 figures, 1 table.

Royden, L. (Massachusetts Inst. of Tech., Cambridge); Sclater, J.G.; Von Herzen, R.P.

1980-02-01T23:59:59.000Z

230

Heat flow and microearthquake studies, Coso Geothermal Area, China Lake, California. Final report  

DOE Green Energy (OSTI)

The present research effort at the Coso Geothermal Area located on the China Lake Naval Weapons Center, China Lake, California, was concerned with: (1) heat flow studies and (2) microearthquake studies associated with the geothermal phenomena in the Coso Hot Springs area. The sites for ten heat flow boreholes were located primarily using the available seismic ground noise and electrical resistivity data. Difficulty was encountered in the drilling of all of the holes due to altered, porous, faulted, and sometime highly fractures zones. Thermal conductivity measurements were completed using both the needle probe technique and the divided bar apparatus with a cell arrangement. Heat flow values were obtaned by combining equilibrium temperature measurements with the appropriate thermal conductivity values. Heat, in the upper few hundred meters of the subsurface associated with the Coso Geothermal Area, is being transferred by a conductive heat transfer mechanism with a value of approximately 15 ..mu..cal/cm/sup 2/-sec. This is typical of geothermal systems throughout the world and is approximately ten times the normal terrestrial heat flow of 1.5 HFU. The background heat flow for the Coso region is about 3.5 HFU.

Combs, J.

1975-01-01T23:59:59.000Z

231

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

SciTech Connect

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

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

1992-06-01T23:59:59.000Z

232

Heat transfer and pressure drop for air flow through enhanced passages  

SciTech Connect

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

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

1992-06-01T23:59:59.000Z

233

ANALOG COMPUTATION OF TEMPERATURE DISTRIBUTION IN SOLIDS WITH ELECTRICAL HEAT-GENERATION AND TEMPERATURE-DEPENDENT PROPERTIES  

SciTech Connect

A problem which frequently arises in experimentai heat transfer work is that of determining the surface temperature of a tube in which heat is generated electrically. Solution of this problem involves a temperature measurement of the opposite surface to which a correction factor, the temperature drop through the tube wall, must be applied. This temperature drop is obtnined through the solution of the diffurential equation governing the temperature distribution in the tube wall; however, in the case of temperature-dependent properties of thermal conductivity and electrical resistivity, the governing equation is nonlinear, which necessitates special solutions. In this study a hypothetical surface-temperature problem was established, and the solution of the governing nonlinear differential equation was accomplished by means of an electronic analog computer. Assuming variable properties, the example used in this study was that of a one-dimensional steadystate heat flow through both a thick- and a thin- walled tube. (auth)

Harden, D.G.; Bryant, L.T.

1962-11-01T23:59:59.000Z

234

Saturated critical heat flux in a multi-microchannel heat sink fed by a split flow system  

SciTech Connect

An extensive experimental campaign has been carried out for the measurement of saturated critical heat flux in a multi-microchannel copper heat sink. The heat sink was formed by 29 parallel channels that were 199 {mu}m wide and 756 {mu}m deep. In order to increase the critical heat flux and reduce the two-phase pressure drop, a split flow system was implemented with one central inlet at the middle of the channels and two outlets at either end. The base critical heat flux was measured using three HFC Refrigerants (R134a, R236fa and R245fa) for mass fluxes ranging from 250 to 1500 kg/m{sup 2} s, inlet subcoolings from -25 to -5 K and saturation temperatures from 20 to 50 C. The parametric effects of mass velocity, saturation temperature and inlet subcooling were investigated. The analysis showed that significantly higher CHF was obtainable with the split flow system (one inlet-two outlets) compared to the single inlet-single outlet system, providing also a much lower pressure drop. Notably several existing predictive methods matched the experimental data quite well and quantitatively predicted the benefit of higher CHF of the split flow. (author)

Mauro, A.W.; Toto, D. [Department of Energetics, Applied Thermofluidynamics and Air Conditioning Systems, FEDERICO II University, p.le Tecchio 80, 80125 Napoli (Italy); Thome, J.R. [Laboratory of Heat and Mass Transfer (LTCM), Faculty of Engineering (STI), Ecole Polytechnique Federale de Lausanne (EPFL), Station 9, Lausanne CH-1015 (Switzerland); Vanoli, G.P. [Engineering Department, Sannio University, Corso Garibaldi 107, Palazzo dell'Aquila Bosco Lucarelli, 82100 Benevento (Italy)

2010-01-15T23:59:59.000Z

235

Incompressible and Anelastic Flow Simulations on Numerically Generated Grids  

Science Conference Proceedings (OSTI)

In the numerical simulation of incompressible and anelastic flows, it is necessary to solve an elliptic equation at each time step. When the boundaries of such flows are nonrectangular, it may be advantageous to solve the equations on a new, ...

R. D. Sharman; T. L. Keller; M. G. Wurtele

1988-05-01T23:59:59.000Z

236

Variable Refrigerant Flow Air Conditioners and Heat Pumps for Commercial Buildings  

Science Conference Proceedings (OSTI)

Multi-split heat pumps have evolved from a technology suitable for residential and light commercial buildings to variable refrigerant flow (VRF) systems that can provide efficient space conditioning for large commercial buildings. VRF systems are enhanced versions of ductless multi-split systems, permitting more indoor units to be connected to each outdoor unit and providing additional features such as simultaneous heating and cooling and heat recovery. VRF systems are very popular in Asia and Europe and...

2008-01-25T23:59:59.000Z

237

Anomalous recovery of damped radial modes in a circular?sector duct with locally heated flow  

Science Conference Proceedings (OSTI)

It is often desirable to predict acoustic propagation in a circular duct carrying a locally heated flow. Common examples include jet engines and certain industrial and commercial burners whose combustion?related noise can be an environmental problem if allowed to penetrate into the surroundings. In these cases axial gradients in the steady flow variables

J. R. Maham; S.?Y. Yeh

1984-01-01T23:59:59.000Z

238

Implicitly balanced solution of the two-phase flow equations coupled to nonlinear heat conduction  

Science Conference Proceedings (OSTI)

This paper presents the solution of the two-phase flow equations coupled to nonlinear heat conduction using the Jacobian-free Newton-Krylov (JFNK) method which employs a physics-based preconditioner. Computer simulations will demonstrate that the implicitly ... Keywords: implicit, nonlinear, preconditioning, two-phase flow

V. A. Mousseau

2004-10-01T23:59:59.000Z

239

Numerical Investigation of Heat Transfer to Fully Developed Turbulent Air Flow in a Concentric Pipe  

Science Conference Proceedings (OSTI)

Numerical simulation using standard k-e turbulencemodel was developed to investigate numerically thecharacteristic of backward-facing step flow in a concentricpipe. This research is focused on the surface temperature, localheat transfer coefficient and ... Keywords: Numerical Simulation, Heat Transfer, Turbulent Flow, Computational Fluid Dynamics, Backward Facing Step

Cheen Sean Oon, Ahmad Badarudin, Salim Newaz Kazi, Arif Syazwan

2013-09-01T23:59:59.000Z

240

Problems in suppressing cooling flows in clusters of galaxies by global heat conduction  

E-Print Network (OSTI)

I use a simple analytical model to show that simple heat conduction models cannot significantly suppress cluster cooling flows. I build a static medium where heat conduction globally balances radiative cooling, and then perturb it. I show that a perturbation extending over a large fraction of the cooling flow region will grow to the non-linear regime within a Hubble time. Such perturbations are reasonable in clusters which frequently experience mergers and/or AGN activity. This result strengthens previous findings which show that a steady solution does not exist for a constant heat conduction coefficient.

Noam Soker

2003-02-19T23:59:59.000Z

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.


241

A heat exchanger between forced flow helium gas at 14 to 18 K and liquid hydrogen at 20 K circulated by natural convection  

E-Print Network (OSTI)

LBNL-53719 A HEAT EXCHANGER BETWEEN FORCED FLOW HELIUM GAShydrogen absorber and the heat exchanger between the liquidpasses through the heat exchanger in the absorber shell. The

Green, M.A.; Ishimoto, S.; Lau, W.; Yang, S.

2003-01-01T23:59:59.000Z

242

The Denver Cyclone. Part I: Generation in Low Froude Number Flow  

Science Conference Proceedings (OSTI)

A numerical model is used to study the “Denver Cyclone,” a mesoscale vortex that develops in eastern Colorado under southerly to southeasterly flow. Diurnal effects (e.g., surface heating/cooling) have been excluded from these simulations, but ...

N. Andrew Crook; Terry L. Clark; Mitchell W. Moncrieff

1990-12-01T23:59:59.000Z

243

Federal Energy Management Program: Combined Heat and Power Basics  

NLE Websites -- All DOE Office Websites (Extended Search)

electricity; and the waste heat is used in some type of thermal process. Process flow for a typical CHP system leverages heat created during electricity generation to...

244

Utility of Bromide and Heat Tracers for Aquifer Characterization Affected by Highly Transient Flow Conditions  

SciTech Connect

A tracer test using both bromide and heat tracers conducted at the Integrated Field Research Challenge site in Hanford 300 Area (300A), Washington, provided an instrument for evaluating the utility of bromide and heat tracers for aquifer characterization. The bromide tracer data were critical to improving the calibration of the flow model complicated by the highly dynamic nature of the flow field. However, most bromide concentrations were obtained from fully screened observation wells, lacking depth-specific resolution for vertical characterization. On the other hand, depth-specific temperature data were relatively simple and inexpensive to acquire. However, temperature-driven fluid density effects influenced heat plume movement. Moreover, the temperature data contained “noise” caused by heating during fluid injection and sampling events. Using the hydraulic conductivity distribution obtained from the calibration of the bromide transport model, the temperature depth profiles and arrival times of temperature peaks simulated by the heat transport model were in reasonable agreement with observations. This suggested that heat can be used as a cost-effective proxy for solute tracers for calibration of the hydraulic conductivity distribution, especially in the vertical direction. However, a heat tracer test must be carefully designed and executed to minimize fluid density effects and sources of noise in temperature data. A sensitivity analysis also revealed that heat transport was most sensitive to hydraulic conductivity and porosity, less sensitive to thermal distribution factor, and least sensitive to thermal dispersion and heat conduction. This indicated that the hydraulic conductivity remains the primary calibration parameter for heat transport.

Ma, Rui; Zheng, Chunmiao; Zachara, John M.; Tonkin, Matthew J.

2012-08-29T23:59:59.000Z

245

Time series power flow analysis for distribution connected PV generation.  

SciTech Connect

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

246

Distributed Generation Case Study: Industrial Process Heating (Cogeneration)  

Science Conference Proceedings (OSTI)

This report details candidate distributed generation (DIS-GEN) options and the process used to select a cogeneration system for potential development at an industrial site. The local utility commissioned this evaluation to explore energy partnership opportunities with its customer.

1997-12-31T23:59:59.000Z

247

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

248

Steady-state heat transfer in an inverted U-tube steam generator  

Science Conference Proceedings (OSTI)

Experimental results are presented involving U-tube steam generator tube bundle local heat transfer and fluid conditions during stead-state, full-power operations performed at high temperatures and pressures with conditions typical of a pressurized water reactor (15.0 MPa primary pressure, 600 K steam generator inlet plenum fluid temperatures, 6.2 MPa secondary pressure). The Semiscale (MOD-2C facility represents the state-of-the-art in measurement of tube local heat transfer data and average tube bundle secondary fluid density at several elevations, which allows an estimate of the axial heat transfer and void distributions during steady-state and transient operations. The method of heat transfer data reduction is presented and the heat flux, secondary convective heat transfer coefficient, and void fraction distributions are quantified for steady-state, full-power operations.

Boucher, T.J.

1987-01-01T23:59:59.000Z

249

Low Cost High Performance Generator Technology Program. Volume 5. Heat Pipe Topical  

DOE Green Energy (OSTI)

Research progress towards the development of a heat pipe for use in the Low Cost High Performance Thermoelectric Generator Program is reported for the period May 15, 1975 through June 1975. (TFD)

Not Available

1975-07-01T23:59:59.000Z

250

LBNL's Low-NOx Combustion Technologies for Heat and Power Generation  

NLE Websites -- All DOE Office Websites (Extended Search)

Us Department Contacts Media Contacts LBNL's Low-NOx Combustion Technologies for Heat and Power Generation Speaker(s): Robert Cheng Date: February 2, 1999 - 12:00pm Location: Bldg....

251

Distributed Generation as Combined Heat and Power (DG-CHP) (New...  

Open Energy Info (EERE)

Edit with form History Share this page on Facebook icon Twitter icon Distributed Generation as Combined Heat and Power (DG-CHP) (New York) This is the approved revision of...

252

Contributions of Individual Atmospheric Diabatic Heating Processes to the Generation of Available Potential Energy  

Science Conference Proceedings (OSTI)

The generation of zonal and eddy available potential energy (Gz and Ge) as formulated by Lorenz are computed on a global-, daily-, and synoptic-scale basis to consider the contribution of each diabatic heating component separately and in ...

Joy Romanski; William B. Rossow

2013-06-01T23:59:59.000Z

253

THERMAL DESIGN METHODOLOGY FOR LOW FLOW RATE SINGLE-PHASE AND TWO-PHASE MICRO-CHANNEL HEAT SINKS  

E-Print Network (OSTI)

in Engine Cooling Systems,'' Experimental Heat Transfer, Fluid Mechanics, and Thermodynamics 1997, June 1997, ``A Correlation for Boiling Heat Transfer to Saturated Fluids in Convective Flow,'' Ind. Eng. Chem the engines in automotive applications. Heat is transferred essentially under subcooled flow boiling

Qu, Weilin

254

Spent Nuclear Fuel project photon heat deposition calculation for hygrogen generation within MCO  

DOE Green Energy (OSTI)

Three types of water conditions are analyzed for nuclear heat deposition in a MCO: fully flooded, thick film, and thin film. These heat deposition rates within water can be used to determine gas generation during the different phases of Spent Fuel removal and processing for storage.

Lan, J.S.

1996-08-01T23:59:59.000Z

255

Unbalanced Load Flow for Weakly Meshed Distribution Systems with Distributed Generation  

Science Conference Proceedings (OSTI)

Distributed Generation (DG) can bring support to distribution system, meanwhile, it bring unbalancedness in power source, load and line. Traditional load flow algorithms are not applicable to the weakly meshed distribution system with DGs. First, this ... Keywords: weakly meshed distribution system, distributed generation, unbalanced load flow, sensitivity compensation

Shao-Qiang Hu; Sen-Mao Li

2010-06-01T23:59:59.000Z

256

Table A31. Total Inputs of Energy for Heat, Power, and Electricity Generation  

U.S. Energy Information Administration (EIA) Indexed Site

Total Inputs of Energy for Heat, Power, and Electricity Generation" Total Inputs of Energy for Heat, Power, and Electricity Generation" " by Value of Shipment Categories, Industry Group, and Selected Industries, 1991" " (Continued)" " (Estimates in Trillion Btu)",,,,"Value of Shipments and Receipts(b)" ,,,," (million dollars)" ,,,"-","-","-","-","-","-","RSE" "SIC"," "," "," "," "," "," "," ",500,"Row" "Code(a)","Industry Groups and Industry","Total","Under 20","20-49","50-99","100-249","250-499","and Over","Factors"

257

Table A45. Total Inputs of Energy for Heat, Power, and Electricity Generation  

U.S. Energy Information Administration (EIA) Indexed Site

Total Inputs of Energy for Heat, Power, and Electricity Generation" Total Inputs of Energy for Heat, Power, and Electricity Generation" " by Enclosed Floorspace, Percent Conditioned Floorspace, and Presence of Computer" " Controls for Building Environment, 1991" " (Estimates in Trillion Btu)" ,,"Presence of Computer Controls" ,," for Buildings Environment",,"RSE" "Enclosed Floorspace and"," ","--------------","--------------","Row" "Percent Conditioned Floorspace","Total","Present","Not Present","Factors" " "," " "RSE Column Factors:",0.8,1.3,0.9 "ALL SQUARE FEET CATEGORIES" "Approximate Conditioned Floorspace"

258

Control of Fluid Flow, Heat Transfer and Inclusions in Continuous ...  

Science Conference Proceedings (OSTI)

Dynamics of Magnetically Levitated Liquid Droplets ... and Thermal Interaction of Nanoparticles in Hyperthermia Cancer Therapy and Solar Energy Systems. ... Molten Oxide Electrolysis for Lunar Oxygen Generation using in situ Resources.

259

Relationship Between Heat Flows and Geological Structures in the Sichuan Basin, P.R. China  

DOE Green Energy (OSTI)

Based on an extensive data collection and analysis, this research has provided reliable representations of the features of the geothermal fields, their heat flow, and relationships with geological structures in the Sichuan Basin. The isotherms below a depth of 1,000 m show high values in the Central Uplift and the Southwest Uplift, and low values in the Northwest and Southeast Depressions. These features probably indicate undulation of crystalline basement and structural depression. At depths greater than 3,000 m, the isotherms tend to become simpler and regionalized. The mean heat flow in the basin is 69.1 mW/m{sup 2}. In the Central Uplift, the Northwest Depression and the East of the basin, heat-flow values range from 58.6 to 71.2 mW/m{sup 2}, with a mean value of 66.1 mWE/m{sup 2}. In the south and southwest, it varies from 76.6 to 100.5 mW/m{sup 2}, with a mean value of 86.2 mW/m{sup 2}. High heat-flow values occur within the uplift of the crystalline basement in the southwest Sichuan, and the heat flow decreases from the south, through the central area, to the northwest.

Zeng, Y.; Yu, H.; Wang, X.

1995-01-01T23:59:59.000Z

260

Two-Layer Baroclinic Eddy Heat Fluxes: Zonal Flows and Energy Balance  

Science Conference Proceedings (OSTI)

The eddy heat flux generated by statistically equilibrated baroclinic turbulence supported on a uniform, horizontal temperature gradient is examined using a two-layer ?-plane quasigeostrophic model. The dependence of the eddy diffusivity of ...

Andrew F. Thompson; William R. Young

2007-09-01T23:59:59.000Z

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

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

262

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 annual dynamic load of a real project to calculate the first investments, annual operation cost and LCC (life cycle cost) of the four schemes, which are electric chillers, electric chillers with ice-storage system, absorption refrigerating machines using excess heat from power plant and absorption refrigerating machines using excess heat from power plant along with ice-storage system. On the basis of the results, the paper analyzes the prospect of the absorption refrigeration using municipal excess heat, as well as the reasonable heat price, which provides a theoretical basis for municipal heating and cooling co-generation development.

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

2006-01-01T23:59:59.000Z

263

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

264

Tidal flow over threedimensional topography generates outofforcingplane harmonics  

E-Print Network (OSTI)

energy conversion from the barotropic to the baroclinic tide. The generation of internal waves by tidal, a significant amount of the energy converted from barotropic to baroclinic tides can be generated perpendicular of a sphere, J. Fluid Mech., 183, 439­450. Baines, P. G. (2007), Internal tide generation by seamounts, Deep

Texas at Austin. University of

265

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.

Prescott, Donald S. (Shelley, ID); Schober, Robert K. (Midwest City, OK); Beller, John (Idaho Falls, ID)

1992-01-01T23:59:59.000Z

266

Flow-induced vibration in LMFBR steam generators: a state-of-the-art review  

SciTech Connect

This state-of-the-art review identifies and discusses existing methods of flow-induced vibration analysis applicable to steam generators, their limitations, and base-technology needs. Also included are discussions of five different LMFBR steam-generator configurations and important design considerations, failure experiences, possible flow-induced excitation mechanisms, vibration testing, and available methods of vibration analysis. The objectives are to aid LMFBR steam-generator designers in making the best possible evaluation of potential vibration in steam-generator internals, and to provide the basis for development of design guidelines to avoid detrimental flow-induced vibration. (auth)

Shin, Y.S.; Wambsganss, M.W.

1975-05-01T23:59:59.000Z

267

Co-generation of electricity and heat from biogas  

SciTech Connect

Biogas powered co-generation of electricity and hot water is being documented in a full scale demonstration with a 25 kW capacity system. The performance characteristics and effects of operating on biogas for 1400 hours are presented in this paper.

Koelsch, R.K.; Cummings, R.J.; Harrison, C.E.; Jewell, W.J.

1982-12-01T23:59:59.000Z

268

New Heat Flow Models in Fractured Geothermal Reservoirs - Final Report  

DOE Green Energy (OSTI)

This study developed new analytical models for predicting the temperature distribution within a geothermal reservoir following reinjection of water having a temperature different from that of the reservoir. The study consisted of two parts: developing new analytical models for the heat conduction rate into multi-dimensional, parallelepiped matrix blocks and developing new analytical models for the advance of the thermal front through the geothermal reservoir. In the first part of the study, a number of semi-empirical models for the multi-dimensional heat conduction were developed to overcome the limitations to the exact solutions. The exact solution based on a similarity solution to the heat diffusion equation is the best model for the early-time period, but fails when thermal conduction fronts from opposing sides of the matrix block merge. The exact solution based on an infinite series solution was found not to be useful because it required tens of thousands of terms to be include d for accuracy. The best overall model for the entire conduction time was a semi-empirical model based on an exponential conduction rate. In the second part of the study, the early-time period exact solution based on similarity methods and the semi-empirical exponential model were used to develop new analytical models for the location of the thermal front within the reservoir during injection. These equations were based on an energy balance on the water in the fractured network. These convective models allowed for both dual and triple porosity reservoirs, i.e., one or two independent matrix domains. A method for incorporating measured fracture spacing distributions into these convective models was developed. It was found that there were only minor differences in the predicted areal extent of the heated zone between the dual and triple porosity models. Because of its simplicity, the dual porosity model is recommended. These new models can be used for preliminary reservoir studies. Although they are not as accurate as numerical simulators, they are simple, easy and inexpensive to use. These new models can be used to get general information about reservoir behavior before committing to the considerable greater expense of numerical simulation.

Reis, John

2001-03-31T23:59:59.000Z

269

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

SciTech Connect

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

270

Forced convection heat transfer in the transition region between laminar and turbulent flow for a vertical circular tube  

Science Conference Proceedings (OSTI)

In this study, first results of the heat transfer characteristic of a vertical double tube heat exchanger were determined. The heat exchanger was operated under cocurrent-flow conditions. The Reynolds-number was varied in the transition region between ... Keywords: circular tube, forced convection, heat transfer, transition region

D. Huber; H. Walter

2010-07-01T23:59:59.000Z

271

On Water Flow in Hot Fractured Rock -- A Sensitivity Study on the Impact of Fracture-Matrix Heat Transfer  

E-Print Network (OSTI)

for both liquid and heat transfer processes. In order to beprocesses in hot fractured rock with ( 1) flow channeling in fractures, (2) interface reduction in F-M heat transfer,

Birkholzer, Jens T.; Zhang, Yingqi

2005-01-01T23:59:59.000Z

272

Boiler and Heat Recovery Steam Generator Tube Failures: Theory and Practice  

Science Conference Proceedings (OSTI)

Boiler and heat recovery steam generator (HRSG) tube failures have been the primary availability problem for operators of conventional and combined cycle plants for as long as reliable statistics have been kept for each generating source. This book provides owners and operators with the technical basis to address tube failures and create permanent solutions.

2011-12-23T23:59:59.000Z

273

Electrically heated particulate filter with zoned exhaust flow control  

SciTech Connect

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

Gonze, Eugene V [Pinckney, MI

2012-06-26T23:59:59.000Z

274

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

Science Conference Proceedings (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

275

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

Science Conference Proceedings (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

276

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

SciTech Connect

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

277

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

Science Conference Proceedings (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

278

ON THE TRANSFER OF HEAT TO FLUIDS FLOWING THROUGH PIPES, ANNULI, AND PARALLEL PLATES  

SciTech Connect

Nusselt numbers were calculated for heat transfer to fluids flowing through annuli under conditions of uniform heat flux and fully established velocity and temperature profiles. The following cases were considered: (a) laminar flow, (b) slug flow, (c) turbulent flow with molecular conduction only, and (d) turbulent flow with both molecular and eddy conduction. These Nusselt numbers were determined for two conditions: heat transfer from the inner wall only and heat transfer from the outer wall only. The results were correlated by semi-empirical equations. The final results obtained on cases (a), (b), amd (c) are applicable to any fluid, whereas those obtained on (d) are for liquid metals only. Wall- and bulk-temperature relationships for the above four cases were also determined. These relationships were treated as dimensionless temperature ratios. Both the Nusselt numbers ad temperature ratios were evaluated over the r/ sub 1//r/sub 2/ range, zero to unity; the former being the case of the circular pipe, and the later, the case of infinite parallel plates. (auth)

Dwyer, O.E.

1963-01-01T23:59:59.000Z

279

A unified numerical framework model for simulating flow, transport, and heat transfer in porous and fractured media  

E-Print Network (OSTI)

or chemical species in a multiphase porous medium system canand radiation in a multiphase, multicomponent, porous mediummultiphase flow, multicomponent transport, and heat transfer in porous

Wu, Yu-Shu

2004-01-01T23:59:59.000Z

280

Water bath calorimetric study of excess heat generation in 'resonant transfer' plasmas  

E-Print Network (OSTI)

Water bath calorimetry was used to demonstrate one more peculiar phenomenon associated with a certain class of mixed gas plasmas termed resonant transfer, or RT plasmas. Specifically, He/H2 (10%) (500 mTorr), Ar/H2 (10%) (500 mTorr), and H2O(g) (500 and 200 mTorr) plasmas generated with an Evenson microwave cavity consistently yielded on the order of 50% more heat than non RT plasma (controls) such as He, Kr, Kr/H2 (10%), under identical conditions of gas flow, pressure, and microwave operating conditions. The excess power density of RT plasmas was of the order 10 W / cm-3. In earlier studies with these same RT plasmas it was demonstrated that other unusual features were present including dramatic broadening of the hydrogen Balmer series lines, unique vacuum ultraviolet (VUV) lines, and in the case of water plasmas, population inversion of the hydrogen excited states. Both the current results and the earlier results are completely consistent with the existence of a hitherto unknown exothermic chemical reaction, such as that predicted by Mills, occurring in RT plasmas.

J. Phillips; R. L. Mills; X. Chen

2004-01-26T23:59:59.000Z

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.


281

Steady-state heat transfer in an inverted U-tube steam generator  

SciTech Connect

Experimental results are presented involving U-tube steam generator tube bundle local heat transfer and fluid conditions during steady-state, full-power operations performed at high temperatures and pressures with conditions typical of a pressurized water reactor (15.0 MPa primary pressure, 600 K hot-leg fluid temperatures, 6.2 MPa secondary pressure). The MOD-2C facility represents the state-of-the-art in measurement of tube local heat transfer data and average tube bundle secondary fluid density at several elevations, which allows an estimate of the axial heat transfer and void distributions during steady-state and transient operations. The method of heat transfer data reduction is presented and the heat flux, secondary convective heat transfer coefficient, and void fraction distributions are quantified for steady-state, full-power operations.

Boucher, T.J.

1986-01-01T23:59:59.000Z

282

Flow measurement and characterization in shallow geothermal systems used for downhole heat exchanger applications  

DOE Green Energy (OSTI)

In the largest non-electrical application of geothermal energy presently occurring in the United States, over 400 relatively shallow wells are being used for extraction of energy with downhole heat exchangers. Despite this large amount of application, the exact nature of the flows in the wells has not before been characterized. Knowledge to date on the nature of flows in the systems is summarized, and an ongoing experimental program for making appropriate downhole measurements to determine flows is described in detail. Flow characterization was a principal object of this study. Horizontal cross-flows of geothermal fluid may occur at upper and/or lower levels in the well where perforations in the well casing are situated. In addition, natural convection may induce vertical flows within the well casing which would be influenced by the presence or absence of a heat exchanger. Three main aspects of the experimental program are reported on: (i) a review of potentially applicable methods for measuring vertical and horizontal flows in wells, (ii) the limitations and preliminary results of using a vane anemometer for measuring vertical flows, and (iii) the description of the selected hot-film probe, its associated pressurized calibration facility, and means of making well measurements.

Churchill, D.; Culver, G.G.; Reistad, G.M.

1977-01-01T23:59:59.000Z

283

Vibration effects of two-phase cross flow on heat exchangers  

SciTech Connect

Excessive flow-induced vibration in tube bundles causes costly tube failures by fatigue or fretting wear. This is a common condition in many shell-and-tube heat exchangers, such as condensers and reboilers. However, designers can't plan for phenomena that they don't understand. To avoid cross-flow vibration damage, the designer must determine flow-behavior effects on tube bundles under these conditions. And this is very true when discussing two-phase cross-flow vibration. Two-phase cross-flow vibration does cause tube/tube bundle failure. Early research used single-phase flow models, which failed to accurately predict vibration behavior in a two-phase system. Consequently, single-phase models and assumptions don't apply to two-phase systems and don't accurately describe vibration-behavior for exchanger tubes. Improved heat exchanger design requires more emphasis and development on cross-flow vibration parameters. The paper describes tube vibrations; flow conditions; void-fraction effects; vortex-induced vibration; fluid excitation forces; and tube response.

Lian, H.Y.; Kawaji, M. (Univ. of Toronto, Ontario (Canada)); Chan, A.M.C. (Ontario Hydro Research Div., Toronto (Canada))

1993-03-01T23:59:59.000Z

284

Combined Heat and Power in Biofuels Production and Use of Biofuels for Power Generation  

Science Conference Proceedings (OSTI)

The rise of the biofuels industry presents electric utilities with two types of opportunities: combined heat and power (CHP) applications in biofuel production facilities using topping and bottoming power generation cycles and the use of the biofuels as a fuel in electric power generation. This report reviews production processes for ethanol and biodiesel, including the prospects for CHP applications, and describes power generation opportunities for the use of biofuels in power production, especially in ...

2007-12-17T23:59:59.000Z

285

Investigation of heat exchanger flow arrangement on performance and cost in a geothermal binary cycle  

DOE Green Energy (OSTI)

The performance of an idealized geothermal binary-fluid-cycle energy conversion system is shown to be a function of the temperatures of brine and working fluid leaving the heat exchanger. System power output, heat exchanger area required and initial well and heat exchanger costs are determined for counterflow, single and multi-pass parallel-counterflow exchangers. Results are presented graphically as functions of the brine and working fluid exit temperatures from the exchanger. Use of the system analysis developed is illustrated by showing quantitatively the advantage of the counterflow over the other flow arrangements considered.

Giedt, W.H.

1976-06-15T23:59:59.000Z

286

Generation of multiscale magnetic field by parity-invariant time-periodic flows  

E-Print Network (OSTI)

We study generation of magnetic fields involving large spatial scales by time- and space-periodic small-scale parity-invariant flows. The anisotropic magnetic eddy diffusivity tensor is calculated by the standard procedure involving expansion of magnetic modes and their growth rates in power series in the scale ratio. Our simulations, conducted for flows with random harmonic composition and exponentially decaying energy spectra, demonstrate that enlargement of the spatial scale of magnetic field is beneficial for generation by time-periodic flows. However, they turn out, in general, to be less efficient dynamos, than steady flows.

V. A. Zheligovsky; O. M. Podvigina

2002-07-28T23:59:59.000Z

287

Design Option of Heat Exchanger for the Next Generation Nuclear Plant  

DOE Green Energy (OSTI)

The Next Generation Nuclear Plant (NGNP), a very High temperature Gas-Cooled Reactor (VHTGRS) concept, will provide the first demonstration of a closed-loop Brayton cycle at a commercial scale of a few hundred megawatts electric and hydrogen production. The power conversion system (PCS) for the NGNP will take advantage of the significantly higher reactor outlet temperatures of the VHTGRS to provide higher efficiencies than can be achieved in the current generation of light water reactors. Besides demonstrating a system design that can be used directly for subsequent commercial deployment, the NGNP will demonstrate key technology elements that can be used in subsequent advanced power conversion systems for other Generation IV reactors. In anticipation of the design, development and procurement of an advanced power conversion system for the NGNP, the system integration of the NGNP and hydrogen plant was initiated to identify the important design and technology options that must be considered in evaluating the performance of the proposed NGNP. As part of the system integration of the VHTGRS and hydrogen production plant, the intermediate heat exchanger is used to transfer the process heat from VHTGRS to hydrogen plant. Therefore, the design and configuration of the intermediate heat exchanger are very important. This paper will include analysis of one stage versus two stage heat exchanger design configurations and thermal stress analyses of a printed circuit heat exchanger, helical coil heat exchanger, and shell/tube heat exchanger.

Eung Soo Kim; Chang Oh

2008-09-01T23:59:59.000Z

288

Proximity functions for modeling fluids and heat flow in reservoirs with stochastic fracture distributions  

DOE Green Energy (OSTI)

Conventional approaches to geothermal reservoir modeling have employed a porous medium approximation, but recently methods have been developed which can take into account the different thermodynamic conditions in rock matrix and fractures. The multiple interacting continua method (MINC) treats the thermal and hydraulic interaction between rock matrix and fractures in terms of a set of geometrical parameters. However, this approach was restricted to idealized fracture distributions with regularly shaped matrix blocks. Fractures in geothermal reservoirs usually occur in nearly parallel sets with a certain scatter in orientation, and a stochastic distribution of spacings and apertures. The MINC-method was extended to realistic fracture systems with stochastic distributions. The interaction between matrix and fractures is parameterized in terms of a proximity function, which represents the volume of matrix rock as a function of distance from the fractures. Monte Carlo techniques were employed to compute proximity functions for a number of two-dimensional systems with regular or stochastic fracture distributions. It is shown how the proximity functions can be used to generate computational grids for modeling fluid and heat flow in fractured reservoirs.

Pruess, K.; Karasaki, K.

1982-10-01T23:59:59.000Z

289

System and method for generating current by selective electron heating  

SciTech Connect

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

290

STABLE HEATING OF CLUSTER COOLING FLOWS BY COSMIC-RAY STREAMING  

SciTech Connect

We study heating of cool cores in galaxy clusters by cosmic-ray (CR) streaming using numerical simulations. In this model, CRs are injected by the central active galactic nucleus (AGN) and move outward with Alfven waves. The waves are excited by the streaming itself and become nonlinear. If magnetic fields are large enough, CRs can prevail in and heat the entire core because of a large Alfven velocity. We find that the CR streaming can stably heat both high- and low-temperature clusters for a long time without the assistance of thermal conduction, and it can prevent the development of massive cooling flows. If there is even a minor contribution from thermal conduction, the heating can be stabilized further. We discuss the reason for the stability and indicate that the CR pressure is insensitive to changes in the intracluster medium (ICM) and that the density dependence of the heating term is similar to that of radiative cooling.

Fujita, Yutaka [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043 (Japan); Ohira, Yutaka, E-mail: fujita@vega.ess.sci.osaka-u.ac.jp [Theory Centre, Institute of Particle and Nuclear Studies, KEK, 1-1 Oho, Tsukuba 305-0801 (Japan)

2011-09-10T23:59:59.000Z

291

NUMERICAL ANALYSIS OF FLOW FIELDS GENERATED BY ACCELERATING FLAMES  

E-Print Network (OSTI)

A.J. and Oppenheim, A.K. , "Initial Flame Acceleration in anGeneration of a Shock Wave by a Flame in an Explosive Gas",of Pressure Waves by Accelerating Flames", Tenth Symposium (

Kurylo, J.

2011-01-01T23:59:59.000Z

292

Topical report: Natural convection shutdown heat removal test facility (NSTF) evaluation for generating additional reactor cavity cooling system (RCCS) data.  

DOE Green Energy (OSTI)

As part of the Department of Energy (DOE) Generation IV roadmapping activity, the Very High Temperature gas cooled Reactor (VHTR) has been selected as the principal concept for hydrogen production and other process-heat applications such as district heating and potable water production. On this basis, the DOE has selected the VHTR for additional R&D with the ultimate goal of demonstrating emission-free electricity and hydrogen production with this advanced reactor concept. One of the key passive safety features of the VHTR is the potential for decay heat removal by natural circulation of air in a Reactor Cavity Cooling System (RCCS). The air-cooled RCCS concept is notably similar to the Reactor Vessel Auxiliary Cooling System (RVACS) that was developed for the General Electric PRISM sodium-cooled fast reactor. As part of the DOE R&D program that supported the development of this fast reactor concept, the Natural Convection Shutdown Heat Removal Test Facility (NSTF) was developed at ANL to provide proof-of-concept data for the RVACS under prototypic natural convection flow, temperature, and heat flux conditions. Due to the similarity between RVACS and the RCCS, current VHTR R&D plans call for the utilization of the NSTF to provide RCCS model development and validation data, in addition to supporting design validation and optimization activities. Both air-cooled and water-cooled RCCS designs are to be included. In support of this effort, ANL has been tasked with the development of an engineering plan for mechanical and instrumentation modifications to NSTF to ensure that sufficiently detailed temperature, heat flux, velocity and turbulence profiles are obtained to adequately qualify the codes under the expected range of air-cooled RCCS flow conditions. Next year, similar work will be carried out for the alternative option of a water-cooled RCCS design. Analysis activities carried out in support of this experiment planning task have shown that: (a) in the RCCS, strong 3-D effects result in large heat flux, temperature, and heat transfer variations around the tube wall; (b) there is a large difference in the heat transfer coefficient predicted by turbulence models and heat transfer correlations, and this underscores the need of experimental work to validate the thermal performance of the RCCS; and (c) tests at the NSTF would embody all important fluid flow and heat transfer phenomena in the RCCS, in addition to covering the entire parameter ranges that characterize these phenomena. Additional supporting scaling study results are available in Reference 2. The purpose of this work is to develop a high-level engineering plan for mechanical and instrumentation modifications to NSTF in order to meet the following two technical objectives: (1) provide CFD and system-level code development and validation data for the RCCS under prototypic (full-scale) natural convection flow conditions, and (2) support RCCS design validation and optimization. As background for this work, the report begins by providing a summary of the original NSTF design and operational capabilities. Since the facility has not been actively utilized since the early 1990's, the next step is to assess the current facility status. With this background material in place, the data needs and requirements for the facility are then defined on the basis of supporting analysis activities. With the requirements for the facility established, appropriate mechanical and instrumentation modifications to NSTF are then developed in order to meet the overall project objectives. A cost and schedule for modifying the facility to satisfy the RCCS data needs is then provided.

Farmer, M. T.; Kilsdonk, D. J.; Tzanos, C.P.; Lomperski, S.; Aeschlimann, R.W.; Pointer, D.; Nuclear Engineering Division

2005-09-01T23:59:59.000Z

293

Mobile robot path planning algorithm by equivalent conduction heat flow topology optimization  

Science Conference Proceedings (OSTI)

This paper addresses the path planning problem for a point robot moving in a planar environment filled with obstacles. Our approach is based on the principles of thermal conduction and structural topology optimization and rests on the observation that, ... Keywords: Conduction heat flow, Mobile robot, Path planning, Topology optimization

Jae Chun Ryu; Frank Chongwoo Park; Yoon Young Kim

2012-05-01T23:59:59.000Z

294

Heat transfer in oscillating flows with sudden change in cross section  

DOE Green Energy (OSTI)

Oscillating fluid flow (zero mean) with heat transfer, between two parallel plates with a sudden change in cross section, was examined computationally. The flow was assumed to be laminar and incompressible with inflow velocity uniform over the channel cross section but varying sinusoidally with time. Over 30 different cases were examined; these cases cover wide ranges of Re{sub max} (187.5 to 30,000), Va (1 to 350), expansion ratio (1:2, 1:4, 1:8, and 1:12) and A{sub r} (0.68 to 4). Three different geometric cases were considered (asymmetric expansion/contraction, symmetric expansion/contraction, and symmetric blunt body). The heat transfer cases were based on constant wall temperature at higher (heating) or lower (cooling) value than inflow fluid temperature. As a result of the oscillating flow, the fluid undergoes sudden expansion in one-half of the cycle and sudden contraction in the other half. In this paper, one heating case is examined in detail, and conclusions are drawn from all the cases (documented in detail elsewhere). Instantaneous friction factors and heat transfer coefficients, for some ranges, of Re{sub max} and Va, deviated substantially from those predicted with steady-state correlations.

Ibrahim, M.; Hashim, W. [Cleveland State Univ., OH (United States); Tew, R.C.; Dudenhoefer, J.E. [Lewis Research Center, Cleveland, OH (United States)

1994-09-01T23:59:59.000Z

295

Fluid and heat flow in gas-rich geothermal reservoirs  

DOE Green Energy (OSTI)

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

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

1983-07-01T23:59:59.000Z

296

Comparison of calculated results from two analytical models with measured data from a heat-exchanger flow test  

SciTech Connect

Predicted results from both a network flow model and a turbulent flow model were compared with measured results from an air flow test on a half-scale model of the auxiliary heat exchanger for a high-temperature gas-cooled reactor. Measurements of both velocity and pressure were made within the heat exchanger shell side flow field. These measurements were compared with calculated results from both a network flow model and a turbulent flow model. Both analytical models predicted early identical results which, except for some minor anomalies, compared favorably with the measured data.

Carosella, D.P.; Pavlics, P.N.

1983-05-01T23:59:59.000Z

297

Quasi-Geostrophic Topographically Generated Mean Flow over the Continental Margin  

Science Conference Proceedings (OSTI)

Observations of oppositely directed, monthly mean alongshore currents and wind stress over the continental margin off the Pacific coast of North America motivate the theoretical examination of mean flow generation by topographic lee-wave drag. We ...

Roger M. Samelson; J. S. Allen

1987-11-01T23:59:59.000Z

298

COMPUTATION OF TWO-PHASE FLOW IN STEAM GENERATOR  

E-Print Network (OSTI)

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . m/s x vapor mass fraction Greek symbols vapor void fraction vap|eq mass rate of vapor generation of the work- ing fluid in the capillary tube. The presence of liquid­vapor menisci, local void fraction the right or the left arms. Since the overall average void fraction integrated over the loop is fixed, #12

Paris-Sud XI, Université de

299

Numerical Simulations of Dynamos Generated in Spherical Couette Flows  

E-Print Network (OSTI)

,version1-18Oct2010 #12;dynamics generating the dynamo mechanism when the fluid is conducting (section 3 Author manuscript, published in "Geophysical & Astrophysical Fluid Dynamics 104, 2-3 (2011) 221-248" DOI: Ratio of the temporally averaged values of the magnetic energy of the fluid to the kinetic energy

Paris-Sud XI, Université de

300

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 dimensional two-phase (liquid and gas) flows. The main goal is to improve the mod- eling of kinetic imbalance between the phases. We present a method that solves the mix- ture (liquid-gas) mass and enthalpy equations

Paris-Sud XI, Université de

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301

Table A15. Total Inputs of Energy for Heat, Power, and Electricity Generation  

U.S. Energy Information Administration (EIA) Indexed Site

Total Inputs of Energy for Heat, Power, and Electricity Generation" Total Inputs of Energy for Heat, Power, and Electricity Generation" " by Value of Shipment Categories, Industry Group, and Selected Industries, 1994" " (Estimates in Trillion Btu)" ,,,," Value of Shipments and Receipts(b)" ,,,," "," (million dollars)" ,,,,,,,,,"RSE" "SIC"," "," "," "," "," "," "," ",500,"Row" "Code(a)","Industry Group and Industry","Total","Under 20","20-49","50-99","100-249","250-499","and Over","Factors" ,"RSE Column Factors:",0.6,1.3,1,1,0.9,1.2,1.2

302

Critical heat-flux experiments under low-flow conditions in a vertical annulus. [PWR; BWR; LMFBR  

Science Conference Proceedings (OSTI)

An experimental study was performed on critical heat flux (CHF) at low flow conditions for low pressure steam-water upward flow in an annulus. The test section was transparent, therefore, visual observations of dryout as well as various instrumentations were made. The data indicated that a premature CHF occurred due to flow regime transition from churn-turbulent to annular flow. It is shown that the critical heat flux observed in the experiment is essentially similar to a flooding-limited burnout and the critical heat flux can be well reproduced by a nondimensional correlation derived from the previously obtained criterion for flow regime transition. The observed CHF values are much smaller than the standard high quality CHF criteria at low flow, corresponding to the annular flow film dryout. This result is very significant, because the coolability of a heater surface at low flow rates can be drastically reduced by the occurrence of this mode of CHF.

Mishima, K.; Ishii, M.

1982-03-01T23:59:59.000Z

303

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

E-Print Network (OSTI)

A new type air heater was developed, and an experimental set-up was built to analyze its characteristics. Within the Reynolds number from 2000 to 15000, the integrated characteristics in air heater channels with and without holed baffles have been studied experimentally. The experimental results show that the average Nu number increases greatly but the friction factor increases only slightly with the Re number. The Webb performance evaluation criterion has been adopted for analysis purposes. 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 with the hole density at the same hole diameter. The C type baffle has the best performance at the same heat transfer surface area and fan power consumption; its heat transfer rate improves about 44 to 69 percent.

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

2006-01-01T23:59:59.000Z

304

Prevention of Flow Restrictions in Generator Stator Water Cooling Circuits  

Science Conference Proceedings (OSTI)

Generator stator water cooling systems are designed to operate with dissolved oxygen (DO) concentrations of either more than 2 parts per million (ppm) or less than 50 parts per billion (ppb). Large- and small-scale experimental studies and literature surveys show that if the system operates with DO concentration in either design range, copper corrosion-product-particle release rates are low and do not lead to plugging of hollow strands or clogging of strainers. In the range between the extremes -- ...

2002-02-06T23:59:59.000Z

305

Procurement Specification for Horizontal Gas Path Heat Recovery Steam Generator: Avoiding Thermal-Mechanical Fatigue Damage  

Science Conference Proceedings (OSTI)

Many heat recovery steam generators (HRSGs), particularly those equipped with F-class gas turbines that are also subjected to periods of frequent cyclic operation, have experienced premature pressure part failures because of excessive thermal-mechanical fatigue (TMF) damage. The very competitive power generation marketplace has resulted in lowest installed cost often taking precedence over medium- and long-term durability and operating costs.

2009-12-23T23:59:59.000Z

306

Structural and heat-flow implications of infrared anomalies at Mt. Hood, Oregon  

DOE Green Energy (OSTI)

Surface thermal features occur in an area of 9700 m/sup 2/ at Mt. Hood, on the basis of an aerial line-scan survey made April 26, 1973. The distribution of the thermal areas below the summit of Mt. Hood, shown on planimetrically corrected maps at 1 : 12,000, suggests structural control by a fracture system and brecciated zone peripheral to a hornblende-dacite plug dome (Crater Rock), and by a concentric fracture system that may have been associated with development of the present crater. The extent and inferred temperature of the thermal areas permits a preliminary estimate of a heat discharge of 10 megawatts, by analogy with similar fumarole and thermal fields of Mt. Baker, Washington. This figure includes a heat loss of 4 megawatts (MW) via conduction, diffusion, evaporation, and radiation to the atmosphere, and a somewhat less certain loss of 6 MW via fumarolic mass transfer of vapor and advective heat loss from runoff and ice melt. The first part of the estimate is based on two-point models for differential radiant exitance and differential flux via conduction, diffusion, evaporation, and radiation from heat balance of the ground surface. Alternate methods for estimating volcanogenic geothermal flux that assume a quasi-steady state heat flow also yield estimates in the 5-11 MW range. Heat loss equivalent to cooling of the dacite plug dome is judged to be insufficient to account for the heat flux at the fumarole fields.

Friedman, J.D.; Frank, D.

1977-01-01T23:59:59.000Z

307

Calibration of Instrumented Steam Separators to Determine Quality and Flow Distribution in an Operating Steam Generator  

Science Conference Proceedings (OSTI)

This study examined the feasibility of instrumenting steam separators on a steam generator as two-phase flowmeters to measure flow distributions and steam quality near the separator deck plate. Instrumented prototypical separators were tested in a laboratory under steam generator conditions, and test data correlations were developed. The usefulness of such data in the qualification of thermal-hydraulic computer codes was addressed.

1983-01-01T23:59:59.000Z

308

Heat Recovery Steam Generators for Combined Cycle Applications: HRSG Procurement, Design, Construction, and Operation Update  

Science Conference Proceedings (OSTI)

Design alternatives and procurement approaches for heat recovery steam generators, supplemental firing duct burners, and ancillary steam systems are addressed in this report. Power engineers and project developers will find an up-to-date, comprehensive resource for planning, specification and preliminary design in support of combined cycle plant development.

2005-03-29T23:59:59.000Z

309

Optimal Selection of On-Site Generation with Combined Heat and  

E-Print Network (OSTI)

Contract No. DE-AC03-76SF00098 and by the California Energy Commission, Public Interest Energy Research, process, or service by its trade name, trademark, manufacturer, or otherwise, does not necessarily: distributed generation; combined heat and power; decentralised optimisation; microgrid; power quality ABSTRACT

310

Evaluating and Avoiding Heat Recovery Steam Generator Tube Damage Caused by Duct Burners  

Science Conference Proceedings (OSTI)

In heat recovery steam generators (HRSGs), supplemental firing in duct burners introduces the potential for serious HRSG tube failure and damage. Duct burners that are specified, designed, and operated properly can produce a number of significant benefits. This report will assist operators in accruing these benefits.

2007-03-20T23:59:59.000Z

311

Development of Advanced Nondestructive Evaluation Techniques for Heat Recovery Steam Generators  

Science Conference Proceedings (OSTI)

Contemporary heat recovery steam generators (HRSGs) operate with multiple pressures and temperatures that can result in degradation and failure of key components such as HRSG drains. Periodic nondestructive evaluation (NDE) of HRSGs can mitigate catastrophic component failure as well as facilitate effective maintenance planning through early detection of system damage. This technical update describes HRSG drain damage mechanisms and related NDE techniques.

2009-03-27T23:59:59.000Z

312

Dynamic simulation model for non-supplementary firing triple-pressure heat recovery steam generator  

Science Conference Proceedings (OSTI)

By using the modular modeling method, a real-time dynamic simulation model for the non-supplementary tri-pressure reheat Heat Recovery Steam Generator (HRSG) is developed. On the basis of mass and energy conservation law, the paper discusses the model ... Keywords: HRSG, dynamic model, modular modelling, simulation

Ning Cui; Bing-Shu Wang; Xiang-Yang Gong; Jian-Qiang Gao

2007-10-01T23:59:59.000Z

313

Cycle Chemistry Guidelines for Combined Cycle/Heat Recovery Steam Generators (HRSGs)  

Science Conference Proceedings (OSTI)

The cycle chemistry in combined cycle plants influences about 70 of the heat recovery steam generator (HRSG) tube failure mechanisms. These guidelines have been assembled to assist operators and chemists in developing an effective overall cycle chemistry program which will prevent HRSG tube failures (HTF).

2006-03-09T23:59:59.000Z

314

Enhanced Geothermal in Nevada: Extracting Heat From the Earth to Generate  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Enhanced Geothermal in Nevada: Extracting Heat From the Earth to Enhanced Geothermal in Nevada: Extracting Heat From the Earth to Generate Sustainable Power Enhanced Geothermal in Nevada: Extracting Heat From the Earth to Generate Sustainable Power April 12, 2013 - 11:17am Addthis Learn the basics of enhanced geothermal systems technology. I Infographic by Sarah Gerrity. Learn the basics of enhanced geothermal systems technology. I Infographic by Sarah Gerrity. Erin R. Pierce Erin R. Pierce Digital Communications Specialist, Office of Public Affairs What does this project do? Desert Peak 2 is the nation's first commercial enhanced geothermal system to supply electricity to the grid. Based in Churchill County, Nevada, the project has increased power

315

Water flow calorimetry measurements of heat loads for a volume production H/sup -/ source  

DOE Green Energy (OSTI)

The design of volume-production H/sup -/ sources requires the knowledge of heat loads on the source components. The arc and filament heater power input to a 20 cm diameter x 23 cm long source can be 50 kW or higher, practically all of which is absorbed in the cooling water. Water flow calorimetry measurements were made to determine the heat loads on the bucket walls, grid no. 1, and magnetic filter rods. The measurements are presented for two different filament locations, for three different values of arc power, and for three values of source gas pressure. 1 ref., 4 figs., 2 tabs.

Purgalis, P.; Ackerman, G.; Kwan, J.; Wells, R.P.

1987-10-01T23:59:59.000Z

316

Modeling Free Convection Flow of Liquid Hydrogen within a Cylindrical Heat Exchanger Cooled to 14 K  

DOE Green Energy (OSTI)

A liquid hydrogen in a absorber for muon cooling requires that up to 300 W be removed from 20 liters of liquid hydrogen. The wall of the container is a heat exchanger between the hydrogen and 14 K helium gas in channels within the wall. The warm liquid hydrogen is circulated down the cylindrical walls of the absorber by free convection. The flow of the hydrogen is studied using FEA methods for two cases and the heat transfer coefficient to the wall is calculated. The first case is when the wall is bare. The second case is when there is a duct some distance inside the cooled wall.

Green, Michael A.; Oxford U.; Yang, S.W.; Green, M.A.; Lau, W.

2004-05-08T23:59:59.000Z

317

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

Science Conference Proceedings (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

318

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

SciTech Connect

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

319

High-Resolution Large-Eddy Simulations of Flow in a Steep Alpine Valley. Part II: Flow Structure and Heat Budgets  

Science Conference Proceedings (OSTI)

This paper analyzes the three-dimensional flow structure and the heat budget in a typical medium-sized and steep Alpine valley—the Riviera Valley in southern Switzerland. Aircraft measurements from the Mesoscale Alpine Programme (MAP)-Riviera ...

Andreas P. Weigel; Fotini K. Chow; Mathias W. Rotach; Robert L. Street; Ming Xue

2006-01-01T23:59:59.000Z

320

Selenide isotope generator for the Galileo Mission. Axially-grooved heat pipe: accelerated life test results  

SciTech Connect

The results through SIG/Galileo contract close-out of accelerated life testing performed from June 1978 to June 1979 on axially-grooved, copper/water heat pipes are presented. The primary objective of the test was to determine the expected lifetime of axially-grooved copper/water heat pipes. The heat pipe failure rate, due to either a leak or a build-up of non-condensible gas, was determined. The secondary objective of the test was to determine the effects of time and temperature on the thermal performance parameters relevant to long-term (> 50,000 h) operation on a space power generator. The results showed that the gas generation rate appears to be constant with time after an initial sharp rise although there are indications that it drops to approximately zero beyond approx. 2000 h. During the life test, the following pipe-hours were accumulated: 159,000 at 125/sup 0/C, 54,000 at 165/sup 0/C, 48,000 at 185/sup 0/C, and 8500 at 225/sup 0/C. Heated hours per pipe ranged from 1000 to 7500 with an average of 4720. Applying calculated acceleration factors yields the equivalent of 930,000 pipe-h at 125/sup 0/C. Including the accelerated hours on vendor tested pipes raises this number to 1,430,000 pipe-hours at 125/sup 0/C. It was concluded that, for a heat pipe temperature of 125/sup 0/C and a mission time of 50,000 h, the demonstrated heat pipe reliability is between 80% (based on 159,000 actual pipe-h at 125/sup 0/C) and 98% (based on 1,430,000 accelerated pipe-h at 125/sup 0/C). Measurements indicate some degradation of heat transfer with time, but no detectable degradation of heat transport. (LCL)

1979-08-01T23:59:59.000Z

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.


321

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

SciTech Connect

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

322

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

SciTech Connect

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

323

Heat flow in the Coso geothermal area, Inyo County, California | Open  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Heat flow in the Coso geothermal area, Inyo County, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat flow in the Coso geothermal area, Inyo County, California Details Activities (2) Areas (1) Regions (0) Abstract: Obvious surface manifestations of an anomalous concentration of geothermal resources at the Coso geothermal area, Inyo County, California, include fumarolic activity and associated hydrothermally altered rocks. Pleistocene volcanic rocks associated with the geothermal activity include 38 rhyolite domes occupying a north trending structural and topographic

324

Airborne-temperature-survey maps of heat-flow anomalies for exploration geology  

DOE Green Energy (OSTI)

Airborne temperature surveys were used to depict the small surface temperature differences related to heat flow anomalies. Zones with conductive heat flow differences of 45 +- 16 ..mu..cal/cm/sup 2/(s) had predawn surface temperature differences of 1.4 +- 0.3/sup 0/C. Airborne temperature surveys were coordinated with field temperature surveys at Long Valley, California, the site of a known geothermal resource area. The airborne temperature surveys recorded redundant, predawn temperatures at two wavelengths and at two elevations. Overall temperature corrections were determined by calibrating dry soil surface temperatures with thermistor probes. The probes measured air and soil temperatures within 2 cm of the surface, every twenty minutes, during the survey overflights.

Del Grande, N.K.

1982-07-09T23:59:59.000Z

325

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

DOE Green Energy (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

326

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

E-Print Network (OSTI)

resources for electric power generation. i. Plant size ii.SYSTEMS Electric Power Generation Systems NonelectricFLUIDS FOR ELECTRIC POWER GENERATION AND NONELECTRIC HEATING

Apps, J.A.

2011-01-01T23:59:59.000Z

327

Basic study of heat flow in fusion welding. Progress report, March 1, 1980-February 28, 1981  

SciTech Connect

During the past year the study of electroslag welding was essentially completed with good agreement between the experimental and the theoretical results. It is concluded that the ESW process has certain inherent limitations which were not appreciated previously. The study has expanded into a more complete analysis of heat and fluid flow in arc welding. It has been shown that the heat affected zone and fusion zone sizes are not simple functions of the net heat input as predicted by all current theories. This will affect the choice of welding parameters. For example, in single pass arc welds, the smallest HAZ is usually desirable, while in multipass welding large HAZ's may be desirable to provide tempering of the previous weld beads. It may be possible to achieve both these goals at equivalent heat input by proper adjustment of the welding parameters (such as voltage, current and travel speed). Goal of the current study is to predict which combinations of parameters maximize or minimize the size of the heat affected zone and fusion zone at equal heat input.

Szekely, J.; Eagar, T.W.

1981-01-01T23:59:59.000Z

328

Comparing Variable Refrigerant Flow to Traditional Heating and Cooling Technologies: Assessing VRF Performance in Mobile, Alabama  

Science Conference Proceedings (OSTI)

In America, most conditioned air is delivered by ductwork, which is often made of sheet metal covered in insulation and installed during construction. However, in Japan and Europe, because the office buildings often pre-date the invention of air conditioning, it is easier and more common for refrigerant pipes to run to wall- or ceiling-mounted heat exchangers. Using refrigerant pipes instead of ducting can eliminate duct loss and offer more precise control. Are Variable Refrigerant Flow (VRF) ...

2013-09-04T23:59:59.000Z

329

Performance Assessment of a Variable Refrigerant Flow Heat Pump Air Conditioning System  

Science Conference Proceedings (OSTI)

Variable refrigerant flow (VRF) technology uses smart integrated controls, variable speed drives, and refrigerant piping to provide energy efficiency, flexible operation, ease of installation, low noise, zone control, and comfort through all-electric technology. This report describes and documents the construction, performance, and application of a heat pump air conditioning system that uses VRF technology8212the Daikin VRV system. This variable refrigerant volume (VRV) system is manufactured by Daikin I...

2008-12-17T23:59:59.000Z

330

A blow-up criterion for compressible viscous heat-conductive flows  

E-Print Network (OSTI)

We study an initial boundary value problem for the Navier-Stokes equations of compressible viscous heat-conductive fluids in a 2-D periodic domain or the unit square domain. We establish a blow-up criterion for the local strong solutions in terms of the gradient of the velocity only, which coincides with the famous Beale-Kato-Majda criterion for ideal incompressible flows.

Jiang, Song

2010-01-01T23:59:59.000Z

331

Electron heating and acceleration by magnetic reconnection in hot accretion flows  

E-Print Network (OSTI)

Both analytical and numerical works show that magnetic reconnection must occur in hot accretion flows. This process will effectively heat and accelerate electrons. In this paper we use the numerical hybrid simulation of magnetic reconnection plus test-electron method to investigate the electron acceleration and heating due to magnetic reconnection in hot accretion flows. We consider fiducial values of density, temperature, and magnetic parameter $\\beta_e$ (defined as the ratio of the electron pressure to the magnetic pressure) of the accretion flow as $n_{0} \\sim 10^{6} {\\rm cm^{-3}}$, $T_{e}^0\\sim 2\\times 10^9 {\\rm K}$, and $\\beta_e=1$. We find that electrons are heated to a higher temperature $T_{e}=5\\times 10^9$K, and a fraction $\\eta\\sim 8%$ of electrons are accelerated into a broken power-law distribution, $dN(\\gamma)\\propto \\gamma^{-p}$, with $p\\approx 1.5$ and 4 below and above $\\sim 1$ MeV, respectively. We also investigate the effect of varying $\\beta$ and $n_0$. We find that when $\\beta_e$ is smalle...

Ding, Jian; Liang, Edison

2009-01-01T23:59:59.000Z

332

ELECTRON HEATING AND ACCELERATION BY MAGNETIC RECONNECTION IN HOT ACCRETION FLOWS  

Science Conference Proceedings (OSTI)

Both analytical and numerical works show that magnetic reconnection must occur in hot accretion flows. This process will effectively heat and accelerate electrons. In this paper, we use the numerical hybrid simulation of magnetic reconnection plus the test-electron method to investigate the electron acceleration and heating due to magnetic reconnection in hot accretion flows. We consider fiducial values of density, temperature, and magnetic parameter beta{sub e} (defined as the ratio of the electron pressure to the magnetic pressure) of the accretion flow as n{sub 0} approx 10{sup 6} cm{sup -3}, T {sup 0}{sub e} approx 2 x 10{sup 9} K, and beta{sub e} = 1. We find that electrons are heated to a higher temperature T{sub e} = 5 x 10{sup 9} K, and a fraction eta approx 8% of electrons are accelerated into a broken power-law distribution, dN(gamma) propor to gamma{sup -p}, with p approx 1.5 and 4 below and above approx1 MeV, respectively. We also investigate the effect of varying beta and n{sub 0}. We find that when beta{sub e} is smaller or n{sub 0} is larger, i.e., the magnetic field is stronger, T{sub e} , eta, and p all become larger.

Ding Jian; Yuan Feng [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China); Liang, Edison, E-mail: fyuan@shao.ac.c [Department of Physics and Astronomy, Rice University, Houston, Texas, 77005 (United States)

2010-01-10T23:59:59.000Z

333

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 semi-rational resistance coefficient formula in rough region, the calculation methods of the sewage flow resistance are explained. Through the resistance contrastive analysis of sewage and pure mediate water, the results indicate that the mediate water sub-system is the primary design point of the TDHT system. The economical ratio of flux and velocity is determined by optimization analysis of investment and operating cost in the technical feasible range. The paper will provide reference for pipe design and pump selection of urban sewage cool or heat source applied delivery heat transfer methods.

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

2006-01-01T23:59:59.000Z

334

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  

Science Conference Proceedings (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

335

Experimental shellside flow visualization in a shell and tube heat exchanger  

E-Print Network (OSTI)

Shell and tube heat exchangers are an extremely effective and mechanically feasible method of transferring thermal energy between two fluids. There is great demand for effective design methods capable of producing highly efficient models. To further improve efficiency, there must be an increased understanding of the physics of shellside flow at a local level. To accomplish this end, an experimental investigation was conducted to obtain flow visualization and internal local pressure drop 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 2.21 L/s were studied. Flow visualization photographs confirmed the existence of leakage streams and recirculation zones. Anomalous vortices were also detected under certain circumstances. Global experimental pressure drops were in good agreement with values predicted from other methods. Local internal pressure dro s were also recorded for the first time and were in good agreement with what would be expected from conventional theory.

Fischer, Matthew Winslow

1998-01-01T23:59:59.000Z

336

Generation of zonal flows by electrostatic drift waves in electron-positron-ion plasmas  

Science Conference Proceedings (OSTI)

Generation of large-scale zonal flows by comparatively small-scale electrostatic drift waves in electron-positron-ion plasmas is considered. The generation mechanism is based on the parametric excitation of convective cells by finite amplitude drift waves having arbitrary wavelengths (as compared with the ion Larmor radius of plasma ions at the plasma electron temperature). Temperature inhomogeneity of electrons and positrons is taken into account assuming ions to be cold. To describe the generation of zonal flow generalized Hasegawa-Mima equation containing both vector and two scalar (of different nature) nonlinearities is used. A set of coupled equations describing the nonlinear interaction of drift waves and zonal flows is deduced. Explicit expressions for the maximum growth rate as well as for the optimal spatial dimensions of the zonal flows are obtained. Enriched possibilities of zonal flow generation with different growth rates are revealed. The present theory can be used for interpretations of drift wave observations in laboratory and astrophysical plasmas.

Kaladze, T. D. [Department of Physics, Government College University, 54000 Lahore (Pakistan); I. Vekua Institute of Applied Mathematics, Tbilisi State University, 2 University Str., 0186 Tbilisi (Georgia); Shad, M. [Department of Physics, Government College University, 54000 Lahore (Pakistan); Tsamalashvili, L. V. [I. Vekua Institute of Applied Mathematics, Tbilisi State University, 2 University Str., 0186 Tbilisi (Georgia)

2010-02-15T23:59:59.000Z

337

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

SciTech Connect

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

338

Generation of a Magnetic Field by Dynamo Action in a Turbulent Flow of Liquid Sodium  

SciTech Connect

We report the observation of dynamo action in the von Karman sodium experiment, i.e., the generation of a magnetic field by a strongly turbulent swirling flow of liquid sodium. Both mean and fluctuating parts of the field are studied. The dynamo threshold corresponds to a magnetic Reynolds number R{sub m}{approx}30. A mean magnetic field of the order of 40 G is observed 30% above threshold at the flow lateral boundary. The rms fluctuations are larger than the corresponding mean value for two of the components. The scaling of the mean square magnetic field is compared to a prediction previously made for high Reynolds number flows.

Monchaux, R.; Chiffaudel, A.; Daviaud, F.; Dubrulle, B.; Gasquet, C.; Marie, L.; Ravelet, F. [Service de Physique de l'Etat Condense, Direction des Sciences de la Matiere, CEA-Saclay, CNRS URA 2464, 91191 Gif-sur-Yvette cedex (France); Berhanu, M.; Fauve, S.; Mordant, N.; Petrelis, F. [Laboratoire de Physique Statistique de l'Ecole Normale Superieure, CNRS UMR 8550, 24 Rue Lhomond, 75231 Paris Cedex 05 (France); Bourgoin, M.; Moulin, M.; Odier, Ph.; Pinton, J.-F.; Volk, R. [Laboratoire de Physique de l'Ecole Normale Superieure de Lyon, CNRS UMR 5672, 46 allee d'Italie, 69364 Lyon Cedex 07 (France)

2007-01-26T23:59:59.000Z

339

HRE-3 BLANKET HEAT EXCHANGER AS A FEEDWATER REACTOR RATHER THAN AS A STEAM GENERATOR  

SciTech Connect

There may be an advantage to designing the HRE-3 vertical shell and tube slurry heat exchanger as a feedwater heater rather than as a steam generator from the standpoint of space requirement and blowdown problems. This study of the effect of this arrangement on the thermal efficiency of the heat-power cycle indicates that the gross electrical generating capacity of HRE-3 would be reduced by about 500-kw, or about 3 to 4% of the output. It is concluded that, (a) there is sufficient merit in using the exchanger as a feedwater heater to warrant continued study of the concept, and (b) the effect on the thermal efficiency is so small as to not be a major deciding influence. (auth)

Robertson, R.C.

1958-04-14T23:59:59.000Z

340

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

Science Conference Proceedings (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

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

Evaluation Metrics for Intermediate Heat Exchangers for Next Generation Nuclear Reactors  

SciTech Connect

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

342

VFL-HF heating of the lower ionosphere and ELF wave generation  

SciTech Connect

For incident wave power densities of 10{sup {minus}6} {minus} 10{sup {minus}2} W/m{sup 2} (at 30 km altitude), VLF heating of the D-region (< 90 km) is found to be 2-10 times more effective (depending on power) than HF heating, resulting in comparable perturbations of subionospheric VLF probe waves in spite of up to 10{sup 3} times larger power density utilized in HF heating and at least as efficient in ELF wave generation. In view of generally larger (100 {times} 100 km) area of the ionosphere illuminated by VLF transmitters, ELF wave generation by modulated VLF heating is estimated to produce ELF power levels of {approximately}100 mW, comparable with or larger than those produced in typical midlatitude ambient ionosphere occurs primarily via the modulation of Pedersen current whereas in a typical auroral ionosphere Hall current is dominant for pump wave frequencies up to {approximately}6 MHz. For 10-30 MHz and power densities > 10{sup {minus}4} W/m{sup 2}, Pedersen current modulation is again dominant, potentially providing up to 2-15 times higher ELF dipole moment than those found in recent experiments using 3-5 MHz heaters.

Taranenko, Y.N.; Inan, U.S.; Bell, T.F. (Stanford Univ., CA (United States))

1992-01-03T23:59:59.000Z

343

Guidelines for the Nondestructive Examination of Heat Recovery Steam Generators, Revision 2  

Science Conference Proceedings (OSTI)

As heat recovery steam generators (HRSGs) have become more complex over the last 20 years, operating with multiple pressures and temperatures, operators have experienced an increasing suite of HRSG tube failures (HTFs). This report provides guidance on the performance of nondestructive evaluation (NDE) of HRSGs so that operators will know what types of NDE to perform and where to perform them.BackgroundModern HRSGs have numerous varieties available within the ...

2013-12-16T23:59:59.000Z

344

Study for Snake Robot Technology for Inspection of Headers and Tubes in Heat Recovery Steam Generators  

Science Conference Proceedings (OSTI)

Heat recovery steam generator (HRSG) tubing is especially difficult to inspect using conventional nondestructive evaluation (NDE) techniques because: The tubing is tightly bundled, with interior bundle tubing typically inaccessible by conventional equipment without cutting and later repairing the exterior tubes. The tubing is finned and, since ultrasonic techniques require solid contact with the tube, cannot be accessed unless the tubing is cut away. Access to the inside of the tubes is difficult, requi...

2009-11-10T23:59:59.000Z

345

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

346

Heat Recovery Steam Generator Procurement Guideline: HRSG Design Best Practices and Specification for Cyclic Duty  

Science Conference Proceedings (OSTI)

This document provides a summary of best practices for designing a new heat recovery steam generator (HRSG) for cycling and rapid start duty, including typical performance requirements and suggestions for design improvements to improve the HRSGs ability to handle cyclic operation. This document also provides a generic procurement specification for the definition and purchase of an HRSG for installation downstream of a combustion turbine. It includes both horizontal and vertical configuration options. The...

2009-12-16T23:59:59.000Z

347

Evaluation of Thermal-, Creep-, and Corrosion-Fatigue of Heat Recovery Steam Generator Pressure Parts  

Science Conference Proceedings (OSTI)

The worldwide fleet of combined cycle units with heat recovery steam generators (HRSG) has exhibited a disappointing track record with respect to reliability and availability in terms of fatigue HRSG tube failures (HTF) which are thermal transient driven. This report, which forms part of a series, will assist designer, owners, and operators with the technical basis to facilitate specifying, designing, and operating HRSG in a manner to minimize fatigue damage.

2006-03-31T23:59:59.000Z

348

HRSG Startup and Shutdown Guidelines for Avoiding Heat Recovery Steam Generator Pressure Part Failures  

Science Conference Proceedings (OSTI)

Most of the damage to heat recovery steam generator (HRSG) pressure parts is caused by transiently high thermal-mechanical stresses that occur during shutdown and startup, along with cycle chemistry changes imposed by cyclic operation. Unit shutdown and startup impose considerably more potential for cumulative pressure part damage than stable on-load operation does. Essentially every HRSG damage mechanism is exacerbated by cyclic operationeither directly, through transiently high localized stresses appli...

2009-07-28T23:59:59.000Z

349

Troubleshooting Guide for Thermal Transients in Heat Recovery Steam Generators (HRSG)  

Science Conference Proceedings (OSTI)

Over the period 2000-2009 EPRI developed ten reports and guidance documents on Heat Recovery Steam Generator (HRSG) thermal transients. Collectively, these documents provide the information required to identify, address, and minimize thermal transients in HRSG superheaters, reheaters, economizers, and evaporators. This summary report offers an overview of this EPRI work on HRSG transients organized to guide the reader to pertinent sections in the original reports and facilitate troubleshooting.

2009-11-09T23:59:59.000Z

350

Comprehensive Cycle Chemistry Guidelines for Combined Cycle/Heat Recovery Steam Generators (HRSGs)  

Science Conference Proceedings (OSTI)

The purity of water and steam is central to ensuring combined cycle/heat recovery steam generator (HRSG) plant component availability and reliability. These guidelines for combined cycle/HRSG plants provide information on the application of all-volatile treatment (AVT), oxygenated treatment (OT), phosphate treatment (PT), caustic treatment (CT), and amine treatment. The guidelines will help operators reduce corrosion and deposition and thereby achieve significant operation and maintenance cost ...

2013-11-08T23:59:59.000Z

351

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

Science Conference Proceedings (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

352

Performance of a glazed open flow liquid desiccant solar collector for both summer cooling and winter heating: Final report  

DOE Green Energy (OSTI)

This report documents the work performed under DOE Contract ACO3-82SF11658, entitled, ''A Research Study to Determine the Heat and Mass Transfer Characteristics of an Open Flow Solar Collector for Both Summer Cooling and Winter Heating.'' Data and computer simulation results are shown for a glazed, open flow collector used for reconcentrating a lithium chloride solution and for thermal energy collection. A comparison of the glazed collector with an unglazed collector from a previous study is also presented.

McCormick, P.O.; Brown, S.R.; Tucker, S.P.

1983-06-01T23:59:59.000Z

353

Numerical study on coupled fluid flow and heat transfer process in parabolic trough solar collector tube  

SciTech Connect

A unified two-dimensional numerical model was developed for the coupled heat transfer process in parabolic solar collector tube, which includes nature convection, forced convection, heat conduction and fluid-solid conjugate problem. The effects of Rayleigh number (Ra), tube diameter ratio and thermal conductivity of the tube wall on the heat transfer and fluid flow performance were numerically analyzed. The distributions of flow field, temperature field, local Nu and local temperature gradient were examined. The results show that when Ra is larger than 10{sup 5}, the effects of nature convection must be taken into account. With the increase of tube diameter ratio, the Nusselt number in inner tube (Nu{sub 1}) increases and the Nusselt number in annuli space (Nu{sub 2}) decreases. With the increase of tube wall thermal conductivity, Nu{sub 1} decreases and Nu{sub 2} increases. When thermal conductivity is larger than 200 W/(m K), it would have little effects on Nu and average temperatures. Due to the effect of the nature convection, along the circumferential direction (from top to down), the temperature in the cross-section decreases and the temperature gradient on inner tube surface increases at first. Then, the temperature and temperature gradients would present a converse variation at {theta} near {pi}. The local Nu on inner tube outer surface increases along circumferential direction until it reaches a maximum value then it decreases again. (author)

Tao, Y.B.; He, Y.L. [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China)

2010-10-15T23:59:59.000Z

354

Evaluation of Next Generation Nuclear Power Plant (NGNP) Intermediate Heat Exchanger (IHX) Operating Conditions  

DOE Green Energy (OSTI)

This report summarizes results of a preliminary evaluation to determine the operating conditions for the Next Generation Nuclear Plant (NGNP) Intermediate Heat Exchanger (IHX) that will transfer heat from the reactor primary system to the demonstration hydrogen production plant(s). The Department of Energy is currently investigating two primary options for the production of hydrogen using a high temperature reactor as the power source. These options are the High Temperature Electrolysis (HTE) and Sulfur-Iodine (SI) thermochemical hydrogen production processes. However, since the SI process relies entirely on process heat from the reactor, while the HTE process relies primarily on electrical energy with only a small amount of process heat required, the design of the IHX is dictated by the SI process heat requirements. Therefore, the IHX operating conditions were defined assuming 50 MWt is available for the production of hydrogen using the SI process. Three configurations for the intermediate loop were evaluated, including configurations for both direct and indirect power conversion systems. The HYSYS process analysis software was used to perform sensitivity studies to determine the influence of reactor outlet temperatures, intermediate loop working fluids (helium and molten salt), intermediate loop pressures, and intermediate loop piping lengths on NGNP performance and IHX operating conditions. The evaluation of NGNP performance included assessments of overall electric power conversion efficiency and estimated hydrogen production efficiency. Based on these evaluations, recommended IHX operating conditions are defined.

E. A. Harvego

2006-04-01T23:59:59.000Z

355

A Study of Cloud-Generated Radiative Heating and Its Generation of Available Potential Energy. Part ii: Results for a Climatological Zonal Mean January  

Science Conference Proceedings (OSTI)

Cloud-generated radiative heating is computed for January zonal mean conditions for low and midclouds. For both cases, the strongest influence was found to be in the low troposphere, with marked differences in signs and magnitudes. Optically thin ...

R. Stuhlmann; G. L. Smith

1988-12-01T23:59:59.000Z

356

Practical method for modeling fluid and heat flow in fractured porous media  

DOE Green Energy (OSTI)

A Multiple Interacting Continua method (MINC) is presented which is applicable for numerical simulation of heat and multi-phase fluid flow in multidimensional, fractured porous media. This method is a generalization of the double-porosity concept. The partitioning of the flow domain into computational volume elements is based on the criterion of approximate thermodynamic equilibrium at all times within each element. The thermodynamic conditions in the rock matrix are assumed to be primarily controlled by the distance from the fractures, which leads to the use of nested grid blocks. The MINC concept is implemented through the Integral Finite Difference (IFD) method. No analytical approximations are made for the coupling between the fracture and matrix continua. Instead, the transient flow of fluid and heat between matrix and fractures is treated by a numerical method. The geometric parameters needed in a simulation are preprocessed from a specification of fracture spacings and apertures, and the geometry of the matrix blocks. The MINC method is verified by comparison with the analytical solution of Warren and Root. Illustrative applications are given for several geothermal reservoir engineering problems.

Pruess, K.; Narasimhan, T.N.

1982-02-01T23:59:59.000Z

357

Direct contact heat transfer between two immiscible liquids in laminar flow between parallel plates  

DOE Green Energy (OSTI)

The search for new sources of energy has prompted studies concerned with extracting energy from low temperature geothermal reservoirs which may include investigations into direct contact heat transfer due to the caustic nature of the geothermal brine. The heat transfer between two liquids of constant properties in laminar stable flow between infinite insulated horizontal parallel plates was studied. The formulation of the general problem involves two energy equations, one for each layer, which are coupled at the interfacial boundary by conditions of temperature and energy flux compatibility. The method of solution is to use the Laplace transform which then results in the necessity of using infinite series solutions with their associated recursion relationships for the coefficients. Special solutions are developed separately for the case where the fluid properties are the same and for the case of slug-flow or constant velocity. Results are presented for the dimensionless mean temperature profile of either fluid, as they are proven to be the same, as a function of the ratios of viscosities, Peclet numbers, volumetric flow rates and the axial location.

Johnson, R.W.; Jacobs, H.R.; Boehm, R.F.

1975-12-01T23:59:59.000Z

358

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

DOE Green Energy (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 “power panel” 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 “power panels” 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 °C and cold-side temperatures = 40 °C. 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

359

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

360

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

NLE Websites -- All DOE Office Websites (Extended Search)

National Fuel Cell Research Center, 2012 1/22 National Fuel Cell Research Center, 2012 1/22 High Temperature Fuel Cell Tri-Generation of Power, Heat & H 2 from Biogas Jack Brouwer, Ph.D. June 19, 2012 DOE/ NREL Biogas Workshop - Golden, CO © National Fuel Cell Research Center, 2012 2/22 Outline * Introduction and Background * Tri-Generation/Poly-Generation Analyses * OCSD Project Introduction © National Fuel Cell Research Center, 2012 3/22 Introduction and Background * Hydrogen fuel cell vehicle performance is outstanding * Energy density of H 2 is much greater than batteries * Rapid fueling, long range ZEV * H 2 must be produced * energy intensive, may have emissions, fossil fuels, economies of scale * Low volumetric energy density of H 2 compared to current infrastructure fuels (@ STP)

Note: This page contains sample records for the topic "generate heat flow" from the National Library of EnergyBeta (NLEBeta).
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361

FUNDAMENTAL INVESTIGATION OF BOILING HEAT TRANSFER AND TWO-PHASE FLOW  

SciTech Connect

Significantly improved theories of two-phase heat transfer and prediction of departure from nucleate boiling have recently been developed which for the first time are not based on empirical relationships. These theories should be critically analyzed in relation to naval reactor work and tested with all existing data from both classified and unclassified sources. Conflicting analyses of two-phase fluid fiow regimes confuse this area, and essentially no data or theories are avsilable for twophase fiow with superimposed boiling. Theories and understanding of two-phase flow with boiling should be developed, starting from proven theories without boiling, and tested against all existing data or new data as necessary. A substantial start hss been made in analysis of the case of upward annular two-phase flow in vertical channels, based upon modern knowledge of boundary layer and vapor condensation principles. (auth)

Grohse, E.W.; Mueller, G.O.; Findlay, J.A.

1958-10-17T23:59:59.000Z

362

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

SciTech Connect

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

363

Heat Recovery from Coal Gasifiers  

E-Print Network (OSTI)

This paper deals with heat recovery from pressurized entrained and fixed bed coal gasifiers for steam generation. High temperature waste heat, from slagging entrained flow coal gasifier, can be recovered effectively in a series of radiant and convection waste heat boilers. Medium level waste heat leaving fixed bed type gasifiers can be recovered more economically by convection type boilers or shell and tube heat exchangers. An economic analysis for the steam generation and process heat exchanger is presented. Steam generated from the waste heat boiler is used to drive steam turbines for power generation or air compressors for the oxygen plant. Low level heat recovered by process heat exchangers is used to heat product gas or support the energy requirement of the gasification plant. The mechanical design for pressure vessel shell and boiler tubes is discussed. The design considers metallurgical requirements associated with hydrogen rich, high temperature, and high pressure atmosphere.

Wen, H.; Lou, S. C.

1981-01-01T23:59:59.000Z

364

Steam Generator Management Program: Benchmark Study of EPRI and EDF Steam Generator Thermal-Hydraulic and Flow Induced Vibration Cod es  

Science Conference Proceedings (OSTI)

Steam generator thermal-hydraulics software codes and flow induced vibration software codes are used for steam generator design, root cause investigations, and assessment of operational changes. Organizations within the steam generator industry develop and maintain such software codes. Capabilities of existing codes are being challenged by current demands for more comprehensive results to troubleshoot ...

2012-12-12T23:59:59.000Z

365

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

SciTech Connect

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

366

Airborne-temperature-survey maps of heat-flow anomalies for exploration geology  

DOE Green Energy (OSTI)

Precise airborne temperature surveys depicted small predawn surface temperature differences related to heat flow anomalies at the Long Valley, California, KGRA. Zones with conductive heat flow differences of 45 +- 16 ..mu..cal/cm/sup 2/(s) has predawn surface temperature differences of 1.4 +- 0.3/sup 0/C. The warmer zones had hot water circulating in a shallow (less than 60-m-deep) aquifer. Hot water is a useful geochemical indicator of geothermal and mineral resource potential. The precise airborne temperature survey method recorded redundant infrared scanner signals at two wavelengths (10 to 12 ..mu..m and 4.5 to 5.5 ..mu..m) and two elevations (0.3 km and 1.2 km). Ground thermistor probes recorded air and soil temperatures during the survey overflights. Radiometric temperatures were corrected for air-path and reflected-sky-radiation effects. Corrected temperatures were displayed in image form with color-coded maps which depicted 0.24/sup 0/C temperature differences. After accounting for surficial features on the corrected predawn thermal imagery, there remained several anomalous zones. These zones had high temperature gradients at depths from 6 to 30 m, compared to the temperature gradients in nearby areas.

Del Grande, N.K.

1982-11-10T23:59:59.000Z

367

Heat transfer characteristics of circular impinging jet arrays in an annular section with cross flow effects  

E-Print Network (OSTI)

Jet impingement has been shown to be an effective method for enhancing convective heat transfer. There are a variety of applications of impinging jets in industry, including tempering and shaping of glass, annealing of metal and plastic sheets, cooling of electronic components and drying of paper, veneer, etc. Another application is the use of impinging jets in internal cooling channels in modern gas turbine blades. High velocity jets provide an effective way to augment the rate of heat removal from the blades to the cooling air, maintaining the blade temperatures within tolerable and metallurgical limits. This experimental research examines, for turbulent parallel and counter flows of air through an annular channel with holes for jet impingement along the inner tube, the effects of varying the geometries of the channel and the hole array, and the air flow rate, on the heat transfer distribution on the inner surfaces of the outer tube. Air enters one end of the inner tube, whose other end is closed, passes through the holes on the inner tube and exits through one end of the annular passage between the inner and outer tubes. Each hole array has inline or staggered circular holes with a given diameter and has a fixed number of holes around the circumference of the inner tube at any cross section of the annular channel. Heat transfer experiments are performed for Reynolds numbers of 5,000, 12,250 and 30,000 to determine the distribution of the regionally average Nusselt numbers along the outer tube, as a result of the impinging jets along the inner tube. Pressure measurement experiments give the pressure distributions in the airflows in the inner tube and between the inner and outer tubes. The pressure data is needed to determine the mass flow rates of the impinging jets along the inner tube. The results of the experiments are presented and discussed, the Nusselt numbers for the various cases studied are compared and major findings are reported. The results of this investigation should be particularly useful to engineers in the design of the leading edges of airfoils of modern gas turbine blades.

Mhetras, Shantanu Prakash

2002-01-01T23:59:59.000Z

368

CFD Predictions of Severe Accident Steam Generator Flows in a 1/7. Scale Pressurized Water Reactor  

SciTech Connect

Computational Fluid Dynamics (CFD) is applied to steam generator inlet plenum mixing as part of a larger plan covering steam generator tube integrity. The technique is verified by comparing predicted results with severe accident natural circulation data from a 1/7. scale Westinghouse facility. This exercise demonstrates that the technique can predict the natural circulation and mixing phenomena relevant to steam generator tube integrity issues. The model includes primary side flow paths for a single hot leg and steam generator. Qualitatively, the experimentally observed flow phenomena are predicted. The paths of the natural circulation flows and the relative flow proportions are correctly predicted. Quantitatively, comparisons are made with temperatures, mass flows, and other parameters. All predictions are generally within 10% of the experimental values. Overall, there is a high degree of confidence in the CFD technique for prediction of the relevant flow phenomena associated with this type of severe accident sequence. (authors)

Boyd, Christopher; Hardesty, Kelly [U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001 (United States)

2002-07-01T23:59:59.000Z

369

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

SciTech Connect

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

370

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

Science Conference Proceedings (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

371

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

DOE Green Energy (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

372

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

DOE Green Energy (OSTI)

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

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

2008-10-15T23:59:59.000Z

373

Heat flow studies in the Steamboat Mountain-Lemei Rock area, Skamania County, Washington. Information circular 62  

DOE Green Energy (OSTI)

In order to investigate the possible occurrence of geothermal energy in areas of Quaternary basaltic volcanism, the Washington State Department of Natural Resources drilled several 152 m deep heat-flow holes in the Steamboat Mountain-Lemei Rock area of Skamania County, Washington. The study area is located in the southern part of Washington's Cascade Mountains between 45/sup 0/54' and 46/sup 0/07' N. and 121/sup 0/40' and 121/sup 0/53'W. This area was selected for study because geologic mapping had identified a north-trending chain of late Quaternary basaltic volcanoes that had extruded a sequence of lava flows up to 600 m thick and because the chain of volcanoes is areally coincident with a well-defined gravity low with a minimum value of about -110 mgals. Gradients of 52.7 and 53.4/sup 0/C/km and heat flows of 1.8 and 1.6 ..mu..cal/cm/sup 2/sec, respectively, were measured in two drill holes near the east flank of the chain of volcanoes. Gradients of 44.5 and 58/sup 0/C/km and heat flows of 1.3 and 1.6 ..mu..cal/cm/sup 2/ sec, respectively, were measured in two holes near the axis of the chain, and one gradient of 49.8/sup 0/C/km and heat flow of 1.5 ..mu..cal/cm/sup 2/ sec were measured in a drill hole near the west flank of the chain. All gradients and heat flows are terrain corrected. These heat-flow values are typical regional heat-flow values for the Cascade Mountains. The data show that there is no large-sized heat source body within the general area of the heat-flow study. However, there is only one location in Washington, also in the Cascade Mountains, where higher gradients have been measured.

Schuster, J.E.; Blackwell, D.D.; Hammond, P.E.; Huntting, M.T.

1978-01-01T23:59:59.000Z

374

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

E-Print Network (OSTI)

Performance of ground source heat pump system in a near-zerosimulation tool for ground- source heat pump system designflow systems and ground source heat pump systems Abstract

Hong, Tainzhen

2010-01-01T23:59:59.000Z

375

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

376

A Temperature-Profile Method for Estimating Flow Processes in Geologic Heat Pipes  

E-Print Network (OSTI)

change and capillarity—the heat pipe effect, Int. J. Heatgeothermal reservoirs as heat pipes in fractured porousProcesses in Geologic Heat Pipes Jens T. Birkholzer Ernest

Birkholzer, Jens T.

2004-01-01T23:59:59.000Z

377

Unsteady flow and heat transfer in a channel with a built-in tandem of rectangular cylinders  

Science Conference Proceedings (OSTI)

The incompressible unsteady flow past a channel with a pair of cylinders of rectangular cross section, placed in tandem normal to the flow, is investigated by numerical simulation. The objective is to evaluate the effect of cylinder separation distance, S/H, on the flow behavior and heat transfer on the channel walls, over a range of Reynolds numbers. Above a critical Reynolds number, these flows bifurcate to a time-periodic self-sustained oscillatory state. The results reveal for S/H = 2.0 three distinct flow patterns: steady flow (Re = 200), time-periodic oscillatory state (400 {le} Re {le} 800), and quasi-periodic oscillatory flow (Re = 1,000). For S/H 600.

Valencia, A. [Universidad de Chile, Santiago (Chile). Dept. de Ingenieria Mecanica

1996-05-10T23:59:59.000Z

378

Heat flow and geothermal gradients of Irian Jaya-Papua New Guinea: Implications for regional hydrocarbon exploration  

Science Conference Proceedings (OSTI)

Compilation of published and unpublished bottom hole temperatures (corrected for circulation times) obtained from open files and reports of the Indonesian Petroleum Association, Papua Geologic Survey, and the Southeast Asia Petroleum Society, together with published oceanographic heat flow analyses from the surrounding seas, allow an analysis of the regional heat flow and geothermal gradients of New Guinea. In two dimensions the thermal trends may be described as a pervasive west-northwest striking Cordilleran core of cool (2 HFU->4{degree}C/100 m) on the northwest, northeast, east, and southwest. As a first approximation, the heat flow may be viewed as directly proportional to the crustal thickness (as demonstrated from north-south transects across the Central Cordillera), inversely proportional to the age of the ocean crust (offshore), and perturbed by crustal heterogeneities proximal to plate boundaries (e.g., the Northern New Guinea Fault System). As a result, the heat flow distribution affords a record of post-Cretaceous tectonic activities of New Guinea. Using the spatial distribution of geothermal gradients and specific source rock ages, kinetic calculations of hydrocarbon maturities confirmed by recent drilling results suggest thermal variations through space and time that cannot be modeled simply as a function of present day static temperatures. Therefore, in terms of utilizing the present thermal information, hydrocarbon basin exploration strategies must also take into account the tectonically perturbed heat flow history of the region.

Bettis, P.K. (Expatriate-Congo, Houston, TX (USA)); Pigott, J.D. (Univ. of Oklahoma, Norman (USA))

1990-06-01T23:59:59.000Z

379

ESS 2012 Peer Review - New Generation Aqueous Base Redox Flow Battery Component Development - Wei Wang, PNNL  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Generation Aqueous Base Redox Flow Generation Aqueous Base Redox Flow Battery Component Development Wei Wang, Qingtao Luo, Xiaoliang Wei, Bin Li, Zimin Nie, Baowei Chen, Yuyan Shao, Vijayakumar Murugesan, Amy Chen, Gordon, Xia, Liyu Li, Gary Z. Yang, Vincent Sprenkle Pacific Northwest National Laboratory 902 Battelle Boulevard P. O. Box 999 Richland, WA 99352, USA DOE Stationary Energy Storage Program Review, Washington, DC Sept. 26-28, 2012 Dr. Imre Gyuk 1 2 Review of previous work 2.5M, ~30Wh/L, -5~50 o C Mixed-acid VRB Double Energy Density Extend temperature window Charge Discharge Charge Discharge Charge Discharge Catholyte: VO 2+ + Cl - + H 2 O - e VO 2 Cl + 2H + ε co =1.0 V Anolyte: V 3+ + e V 2+ ε ao =-0.25 Overall: VO 2+ + Cl

380

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

SciTech Connect

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

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

2008-01-15T23:59:59.000Z

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

Steam Generator Management Program: Experimental Studies of Flow Around Foreign Objects in a Tube Array  

Science Conference Proceedings (OSTI)

Tube wear caused by foreign objects (FOs) in steam generators can lead to unplanned and costly forced outages. The complex flow field within the tube bundle, coupled with the wide range of FO sizes and possible configurations relative to the tubes, poses a challenge to the understanding of the fundamental mechanisms of FO-tube interaction and prediction of the resulting tube wear.The goals of the project were (1) to develop an experimental apparatus and measurement system capable of ...

2013-12-18T23:59:59.000Z

382

Study for radionuclide transfer ratio of aerosols generated during heat cutting  

SciTech Connect

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

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

2007-07-01T23:59:59.000Z

383

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

SciTech Connect

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

384

Preliminary issues associated with the next generation nuclear plant intermediate heat exchanger design.  

SciTech Connect

The Next Generation Nuclear Plant (NGNP), which is an advanced high temperature gas reactor (HTGR) concept with emphasis on production of both electricity and hydrogen, involves helium as the coolant and a closed-cycle gas turbine for power generation with a core outlet/gas turbine inlet temperature of 900-1000 C. In the indirect cycle system, an intermediate heat exchanger is used to transfer the heat from primary helium from the core to the secondary fluid, which can be helium, nitrogen/helium mixture, or a molten salt. The system concept for the vary high temperature reactor (VHTR) can be a reactor based on the prismatic block of the GT-MHR developed by a consortium led by General Atomics in the U.S. or based on the PBMR design developed by ESKOM of South Africa and British Nuclear Fuels of U.K. This report has made a preliminary assessment on the issues pertaining to the intermediate heat exchanger (IHX) for the NGNP. Two IHX designs namely, shell and tube and compact heat exchangers were considered in the assessment. Printed circuit heat exchanger, among various compact heat exchanger (HX) designs, was selected for the analysis. Irrespective of the design, the material considerations for the construction of the HX are essentially similar, except may be in the fabrication of the units. As a result, we have reviewed in detail the available information on material property data relevant for the construction of HX and made a preliminary assessment of several relevant factors to make a judicious selection of the material for the IHX. The assessment included four primary candidate alloys namely, Alloy 617 (UNS N06617), Alloy 230 (UNS N06230), Alloy 800H (UNS N08810), and Alloy X (UNS N06002) for the IHX. Some of the factors addressed in this report are the tensile, creep, fatigue, creep fatigue, toughness properties for the candidate alloys, thermal aging effects on the mechanical properties, American Society of Mechanical Engineers (ASME) Code compliance information, and performance of the alloys in helium containing a wide range of impurity concentrations. A detailed thermal hydraulic analysis, using a model developed at ANL, was performed to calculate heat transfer, temperature distribution, and pressure drop inside both printed circuit and shell-and-tube heat exchangers. The analysis included evaluation of the role of key process parameters, geometrical factors in HX designs, and material properties. Calculations were performed for helium-to-helium, helium-to-helium/nitrogen, and helium-to-salt HXs. The IHX being a high temperature component, probably needs to be designed using ASME Code Section III, Subsection NH, assuming that the IHX will be classified as a class 1 component. With input from thermal hydraulic calculations performed at ANL, thermal conduction and stress analyses for both compact and shell-and-tube HXs were performed.

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

2007-04-05T23:59:59.000Z

385

NIST Helps Heat Pumps 'Go With the Flow' to Boost Output  

Science Conference Proceedings (OSTI)

... ARTI) under a Cooperative Research and Development Agreement (CRADA), could increase finned-tube heat exchanger heating or cooling ...

2012-03-05T23:59:59.000Z

386

A Temperature-Profile Method for Estimating Flow Processes in Geologic Heat Pipes  

E-Print Network (OSTI)

make sure that the heat transfer processes are approximatelyfocus is on the heat and mass transfer processes within the

Birkholzer, Jens T.

2004-01-01T23:59:59.000Z

387

DOE-HDBK-1012/2-92; DOE Fundamentals Handbook Thermodynamics, Heat Transfer, and Fluid Flow Volume 2 of 3  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

2-92 2-92 JUNE 1992 DOE FUNDAMENTALS HANDBOOK THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW Volume 2 of 3 U.S. Department of Energy FSC-6910 Washington, D.C. 20585 Distribution Statement A. Approved for public release; distribution is unlimited. This document has been reproduced directly from the best available copy. Available to DOE and DOE contractors from the Office of Scientific and Technical Information. P. O. Box 62, Oak Ridge, TN 37831; prices available from (615) 576- 8401. FTS 626-8401. Available to the public from the National Technical Information Service, U.S. Department of Commerce, 5285 Port Royal Rd., Springfield, VA 22161. Order No. DE92019790 THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW Rev. 0 HT ABSTRACT The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was

388

DOE-HDBK-1012/1-92; DOE Fundamentals Handbook Thermodynamics, Heat Transfer, and Fluid Flow Volume 1 of 3  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

1-92 1-92 JUNE 1992 DOE FUNDAMENTALS HANDBOOK THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW Volume 1 of 3 U.S. Department of Energy FSC-6910 Washington, D.C. 20585 Distribution Statement A. Approved for public release; distribution is unlimited. This document has been reproduced directly from the best available copy. Available to DOE and DOE contractors from the Office of Scientific and Technical Information. P. O. Box 62, Oak Ridge, TN 37831; (615) 576-8401. Available to the public from the National Technical Information Service, U.S. Department of Commerce, 5285 Port Royal Rd., Springfield, VA 22161. Order No. DE92019789 THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW Rev. 0 HT ABSTRACT The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance

389

Reply To The Comment By D D Blackwell And G R Priest On Heat Flow From Four  

Open Energy Info (EERE)

Reply To The Comment By D D Blackwell And G R Priest On Heat Flow From Four Reply To The Comment By D D Blackwell And G R Priest On Heat Flow From Four New Research Drill Holes In The Western Cascades, Oregon, Usa By S E Ingebritsen, M A Scholl And D R Sherrod Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Reply To The Comment By D D Blackwell And G R Priest On Heat Flow From Four New Research Drill Holes In The Western Cascades, Oregon, Usa By S E Ingebritsen, M A Scholl And D R Sherrod Details Activities (1) Areas (1) Regions (0) Abstract: Unavailable Author(s): S. E. Ingebritsen, M. A. Scholl, D. R. Sherrod Published: Geothermics, 1996 Document Number: Unavailable DOI: Unavailable Source: View Original Journal Article Geothermal Literature Review At Breitenbush Hot Springs Area (Ingebritsen, Et Al., 1996)

390

DOE-HDBK-1012/3-92; DOE Fundamentals Handbook Thermodynamics, Heat Transfer, and Fluid Flow Volume 3 of 3  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

3-92 3-92 JUNE 1992 DOE FUNDAMENTALS HANDBOOK THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW Volume 3 of 3 U.S. Department of Energy FSC-6910 Washington, D.C. 20585 Distribution Statement A. Approved for public release; distribution is unlimited. This document has been reproduced directly from the best available copy. Available to DOE and DOE contractors from the Office of Scientific and Technical Information. P. O. Box 62, Oak Ridge, TN 37831; prices available from (615) 576- 8401. FTS 626-8401. Available to the public from the National Technical Information Service, U.S. Department of Commerce, 5285 Port Royal Rd., Springfield, VA 22161. Order No. DE92019791 THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW Rev. 0 HT ABSTRACT The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was

391

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

SciTech Connect

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

392

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_aheat from decays of 40-K, 232-Th, 238-U inside the Earth, 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

2008-11-24T23:59:59.000Z

393

Heat flow determinations and implied thermal regime of the Coso geothermal  

Open Energy Info (EERE)

determinations and implied thermal regime of the Coso geothermal determinations and implied thermal regime of the Coso geothermal area, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Heat flow determinations and implied thermal regime of the Coso geothermal area, California Details Activities (1) Areas (1) Regions (0) Abstract: Obvious surface manifestations of an anomalous concentration of geothermal energy at the Coso Geothermal Area, California, include fumarolic activity, active hot springs, and associated hydrothermally altered rocks. Abundant Pleistocene volcanic rocks, including a cluster of thirty-seven rhyolite domes, occupy a north-trending structural and topographic ridge near the center of an oval-shaped zone of late Cenozoic ring faulting. In an investigation of the thermal regime of the geothermal

394

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

E-Print Network (OSTI)

Amarnath, M. Blatt, Variable refrigerant flow: where, why,simulation in the variable refrigerant flow air-conditioningsimulation of the variable refrigerant flow air conditioning

Hong, Tainzhen

2010-01-01T23:59:59.000Z

395

ELF/VLF emissions generated in the ionosphere by heating facilities - a new tool for ionospheric and magnetospheric research  

SciTech Connect

A brief summary of ELF/VLF generation experiments using the SURA heating facility is presented. The possibilities of applications of the measured ionospherically generated low frequency signal parameters for diagnosing the physical phenomena in the ionosphere and the magnetosphere are discussed.

Kotik, D.S. [Radiophysical Research Institute, Nizhny Novgorod (Russian Federation)

1994-12-01T23:59:59.000Z

396

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

Science Conference Proceedings (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

397

Quality Assurance Plan for Heat Source/Radioisotope Thermoelectric Generator Programs  

SciTech Connect

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

398

Quality Assurance Plan for Heat Source/Radioisotope Thermoelectric Generator Programs  

SciTech Connect

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

399

Application of heat-flow techniques to geothermal energy exploration, Leach Hot Springs area, Grass Valley, Nevada  

DOE Green Energy (OSTI)

A total of 82 holes ranging in depth from 18 to 400 meters were drilled for thermal and hydrologic studies in a 200 km/sup 2/ area of Grass Valley, Nevada, near Leach Hot Springs. Outside the immediate area of Leach Hot Springs, heat flow ranges from 1 to 6.5 hfu with a mean of 2.4 hfu (1 hfu = 10/sup -6/ cal cm/sup 2/ s/sup -1/ = 41.8 mWm/sup -2/). Within 2 km of the springs, conductive heat flow ranges between 1.6 and more than 70 hfu averaging 13.6 hfu. Besides the conspicuous thermal anomaly associated with the hot springs, two additional anomalies were identified. One is associated with faults bounding the western margin of the Tobin Range near Panther Canyon, and the other is near the middle of Grass Valley about 5 km SSW of Leach Hot Springs. The mid-valley anomaly appears to be caused by hydrothermal circulation in a bedrock horst beneath about 375 meters of impermeable valley sediments. If the convective and conductive heat discharge within 2 km of the Leach Hot Springs is averaged over the entire hydrologic system (including areas of recharge), the combined heat flux from this part of Grass Valley is about 3 hfu, consistent with the average regional conductive heat flow in the Battle Mountain High. The hydrothermal system can be interpreted as being in a stationary stable phase sustained by high regional heat flow, and no localized crustal heat sources (other than hydrothermal convection to depths of a few kilometers) need be invoked to explain the existence of Leach Hot Springs.

Sass, J.H.; Ziagos, J.P.; Wollenberg, H.A.; Munroe, R.J.; di Somma, D.E.; Lachenbruch, A.H.

1977-01-01T23:59:59.000Z

400

Low Cost High Performance Generator Technology Program. Volume 5. Heat pipe topical, appendices  

SciTech Connect

Work performed by Dynatherm Corporation for Teledyne Isotopes during a program entitled ''Heat Pipe Fabrication, Associated Technical Support and Reporting'' is reported. The program was initiated on November 29, 1972; the main objectives were accomplished with the delivery of the heat pipes for the HPG. Life testing of selected heat pipe specimens is continuing to and beyond the present date. The program consisted of the following tasks: Heat Pipe Development of Process Definition; Prototype Heat Pipes for Fin Segment Test; HPG Heat Pipe Fabrication and Testing; Controlled Heat Pipe Life Test; and Heat Pipe Film Coefficient Determination. (TFD)

1975-07-01T23:59:59.000Z

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

Low Cost High Performance Generator Technology Program. Volume 5. Heat pipe topical, appendices  

DOE Green Energy (OSTI)

Work performed by Dynatherm Corporation for Teledyne Isotopes during a program entitled ''Heat Pipe Fabrication, Associated Technical Support and Reporting'' is reported. The program was initiated on November 29, 1972; the main objectives were accomplished with the delivery of the heat pipes for the HPG. Life testing of selected heat pipe specimens is continuing to and beyond the present date. The program consisted of the following tasks: Heat Pipe Development of Process Definition; Prototype Heat Pipes for Fin Segment Test; HPG Heat Pipe Fabrication and Testing; Controlled Heat Pipe Life Test; and Heat Pipe Film Coefficient Determination. (TFD)

Not Available

1975-07-01T23:59:59.000Z

402

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

E-Print Network (OSTI)

A schematic of the heat pipe problem (from Updegraff [1989])19. A schematic of the heat pipe problem (from Updegraff[Numerical Modeling of a Porous Heat Pipe: Comparison with a

Moridis, G.J.

2010-01-01T23:59:59.000Z

403

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

SciTech Connect

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

404

Heat Transfer and Fluid Flow of Benard-Cell Convection in Rectangular Container with Free Surface Sensed by Infrared Thermography  

Science Conference Proceedings (OSTI)

The natural convection flow phenomena that occur inside an enclosed space are very interesting examples of complex fluid systems that may yield to analytical, empirical and numerical solutions, and many reports have looked into this basic problem. In ... Keywords: Gas-liquid Interface, Heat Transfer, Infrared Thermography, Natural Convection, Thermal Visualization, Turbulence

T. Inagaki; M. Hatori; T. Suzuki; Y. Shiina

2006-04-01T23:59:59.000Z

405

Experiments in the ISX-B tokamak electron cyclotron heating, ripple studies, pellet fueling, impurity flow reversal and surface physics  

DOE Green Energy (OSTI)

The wide variety of experiments on the ISX-B tokamak includes electron cyclotron heating, ripple effects, hydrogen pellet fueling, impurity flow reversal mechanisms, plasma edge studies, and testing of limiter coatings. The most significant results in each of these areas are discussed.

Isler, R.C. [Oak Ridge National Laboratory (ORNL); Peng, Yueng Kay Martin [ORNL

1981-01-01T23:59:59.000Z

406

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

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

407

Some Influences of Background Flow Conditions on the Generation of Turbulence due to Gravity Wave Breaking above Deep Convection  

Science Conference Proceedings (OSTI)

Deep moist convection generates turbulence in the clear air above and around developing clouds, penetrating convective updrafts and mature thunderstorms. This turbulence can be due to shearing instabilities caused by strong flow deformations near ...

Todd P. Lane; Robert D. Sharman

2008-11-01T23:59:59.000Z

408

A low NO/sub x/ combustion system and a ceramic cross flow heat exchanger for small gas turbines  

SciTech Connect

A new low NO/sub x/ oil-combustion system with superheated steam fuel evaporation prior to combustion has been found especially feasible for open cycle gas turbines with high turbine inlet temperatures and ceramic cross flow heat exchanger. The actual state of development of both the low NO/sub x/ light fuel-oil combustion system and ceramic heat exchanger elements, especially the cross flow type, is outlined in this paper. The use of this combustion system results in considerably lower combustion temperatures in the primary combustion zone, reducing the NO/sub x/-production even at high air temperatures when the air is preheated in the heat exchanger. The water vapour used for the evaporation of the fuel oil before combustion has an improving effect on the cycle efficiency comparable to the Cheng-dual-fluid-cycle. Illustrative evaluations for a gas turbine cycle for a shaft power of 70 kW are given.

Forster, S.; Quell, P.

1987-01-01T23:59:59.000Z

409

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

Science Conference Proceedings (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

410

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

411

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

412

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

SciTech Connect

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

413

A Study of Cloud–Generated Radiative Heating and Its Generation of Available Potential Energy. Part I: Theoretical Background  

Science Conference Proceedings (OSTI)

The theory is presented of the effect of radiative heating and cooling by clouds on the available potential energy (APE). This provides a measure of the influence of clouds on the general circulation. Absorption and scattering of solar radiation ...

R. Stuhlmann; G. L. Smith

1988-12-01T23:59:59.000Z

414

On the Heating of the Solar Corona and the Acceleration of the Low-Speed Solar Wind by Acoustic Waves Generated in Corona  

E-Print Network (OSTI)

We investigate possibilities of solar coronal heating by acoustic waves generated not at the photosphere but in the corona, aiming at heating in the mid- to low-latitude corona where the low-speed wind is expected to come from. Acoustic waves of period tau ~ 100s are triggered by chromospheric reconnection, one model of small scale magnetic reconnection events recently proposed by Sturrock. These waves having a finite amplitude eventually form shocks to shape sawtooth waves (N-waves), and directly heat the surrounding corona by dissipation of their wave energy. Outward propagation of the N-waves is treated based on the weak shock theory, so that the heating rate can be evaluated consistently with physical properties of the background coronal plasma without setting a dissipation length in an ad hoc manner. We construct coronal structures from the upper chromosphere to the outside of 1AU for various inputs of the acoustic waves having a range of energy flux of F_{w,0} = (1-20) times 10^5 erg cm^{-2} s^{-1} and a period of tau = 60-300s. The heating by the N-wave dissipation effectively works in the inner corona and we find that the waves of F_{w,0} >= 2 times 10^5 erg cm^{-2} s^{-1} and tau >= 60s could maintain peak coronal temperature, T_{max} > 10^6 K. The model could also reproduce the density profile observed in the streamer region. However, due to its short dissipation length, the location of T_{max} is closer to the surface than the observation, and the resultant flow velocity of the solar wind is lower than the observed profile of the low-speed wind. The cooperations with other heating and acceleration sources with the larger dissipation length are inevitable to reproduce the real solar corona.

Takeru Ken Suzuki

2002-06-14T23:59:59.000Z

415

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

E-Print Network (OSTI)

the burning of natural gas for on-site power generation andnatural gas absorption chiller GenL i , m , t , h , u Generated power by distributed generation

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

2004-01-01T23:59:59.000Z

416

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

DOE Green Energy (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

417

1983 temperature gradient and heat flow drilling project for the State of Washington  

DOE Green Energy (OSTI)

During the Summer of 1983, a three-hole drilling program was carried out to collect temperature gradient and heat flow information near potential geothermal resource target areas. The general locations of the project areas are shown. 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, M.A.

1983-11-01T23:59:59.000Z

418

Cross flow heat exchange of textile cellular metal core sandwich panels , T.J. Lu b,*, H.P. Hodson a  

E-Print Network (OSTI)

Cross flow heat exchange of textile cellular metal core sandwich panels J. Tian a , T.J. Lu b,*, H. Finally, the thermal performance of brazed woven tex- tiles is compared with other heat exchanger media be used as heat exchangers, node rotation precludes their use as structural members. In addition

Wadley, Haydn

419

Heat transfer and fluid dynamics of air-water two-phase flow in micro-channels  

SciTech Connect

Heat transfer, pressure drop, and void fraction were simultaneously measured for upward heated air-water non-boiling two-phase flow in 0.51 mm ID tube to investigate thermo-hydro dynamic characteristics of two-phase flow in micro-channels. At low liquid superficial velocity j{sub l} frictional pressure drop agreed with Mishima-Hibiki's correlation, whereas agreed with Chisholm-Laird's correlation at relatively high j{sub l}. Void fraction was lower than the homogeneous model and conventional empirical correlations. To interpret the decrease of void fraction with decrease of tube diameter, a relation among the void fraction, pressure gradient and tube diameter was derived. Heat transfer coefficient fairly agreed with the data for 1.03 and 2.01 mm ID tubes when j{sub l} was relatively high. But it became lower than that for larger diameter tubes when j{sub l} was low. Analogy between heat transfer and frictional pressure drop was proved to hold roughly for the two-phase flow in micro-channel. But satisfactory relation was not obtained under the condition of low liquid superficial velocity. (author)

Kaji, Masuo; Sawai, Toru; Kagi, Yosuke [Department of Mechanical Engineering, School of Biology-Oriented Science and Technology, Kinki University, 930 Nishi-mitani, Kinokawa, Wakayama 649-6493 (Japan); Ueda, Tadanobu [Toyota Central R and D Laboratory, Incorporated, 41-1 Yokomichi, Nagakute, Aichi 480-1192 (Japan)

2010-05-15T23:59:59.000Z

420

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

SciTech Connect

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

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

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

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

422

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

SciTech Connect

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

423

Diagnostic/Troubleshooting Monitoring to Identify Damaging Cycle Chemistry or Thermal Transients in Heat Recovery Steam Generator Pressure Parts  

Science Conference Proceedings (OSTI)

The worldwide fleet of combined cycle units with heat recovery steam generators (HRSGs) has exhibited a disappointing track record with respect to reliability and availability in terms of HRSG tube failures (HTFs). This report will assist operators in identifying the harmful chemical and thermal transient excursions that lead to failure.

2005-03-07T23:59:59.000Z

424

Wave generation and heating near ion cyclotron frequency in the ST Tokamak  

SciTech Connect

The results of the recent, high power ICRH experiments performed on the ST Tokamak are reported. It was demonstrated that both the fast and slow waves could be generated in toroidal geometry, and heating of the plasma ions at power levels up to 1 MW was observed both at the ion cyclotron frequency ($omega$/sub ci/) and its second harmonic (2$omega$/sub ci/). Measurements by a charge exchange neutral detector directed tangentially to the plasma torus revealed that at 2$omega$/sub ci/ the ion energy within the bulk of the ion distribution function (''parallel body temperature'') could be increased from about 100 eV up to 200 eV with efficiencies ranging from 8 to 45 percent. Efficiency at $omega$/ sub ci/ in raising the parallel temperature was less than at 2$omega$/sub ci/. Charge exchange neutral detection perpendicular to the plasma column showed that both at $omega$/sub ci/ and 2$omega$/sub ci/ the ''perpendicular body temperature'' was enhanced very rapidly by a factor of up to 3. Also, buildup of a high energy ''tail'' in the ion energy distribution was observed. Power transfer to the ions seemed extremely efficient. (auth)

Takahashi, H.

1975-10-01T23:59:59.000Z

425

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

DOE Green Energy (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

426

Milliwatt generator heat source shelf-life-related pressure-burst capsule evaluations  

DOE Green Energy (OSTI)

Three Milliwatt Generator Heat Source (MWGHS) shelf-life-related capsules were pressure-burst tested after thermal aging. Shelf-life capsules PB-08-03 (MC2893) and MPT-11-33 (MC3599) were tested at 1,010 C and capsule PB-07-13 (MC2893) was tested at 1,100 C. Subsequent to pressure-burst testing, each capsule was bubble-leak tested then metallographically examined. Post-mortem evaluation consisted of metallography, microhardness, scanning electron microscopy (SEM), and oxygen and nitrogen analysis. Capsules PB-08-03 and PB-07-13 failed by elevated temperature stress-rupture in the coarse-grained cap to body welds, as has been documented for previous capsules. Pressure-burst testing of capsule MPT-11-33 was terminated prior to failure after 739 hours on test at 1,010 C, however, microscopic examination of the weld indicated that similar failure had began to occur in the interior portion of the capsule to body weld. Evidence was obtained indicating that metallurgical changes occurred during the pressure-burst test performed at 1,100 C. The metallurgical observations of a preferred site for elevated temperature deformation and fracture (the coarse-grained weld region) and structural instability (the property changes during testing at 1,100 C) need to be considered in component lifetime prediction and modeling efforts.

Ritchey, B.D.; Eckelmeyer, K.H.; Kilgo, A.C.; McKenzie, B.B.

1997-10-01T23:59:59.000Z

427

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

DOE Green Energy (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

428

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

Science Conference Proceedings (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 900°C 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. Today’s high-temperature alloys and associated ASME Codes for reactor applications are approved up to 760°C. 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

429

Downward two-phase flow effects in heat-loss and pressure-drop modeling of steam injection wells  

SciTech Connect

Modelling of the pressure drop and heat loss in steam injection wells has undergone a gradual evolution since the heavy interest in enhanced oil recovery by steam injection in the mid-60's. After briefly reviewing the evolution of steam models this paper presents a model which advances the state-of-the-art of steam modelling. The main advance presented in this paper is modelling the effects of the various flow regimens that occur during steam injection. The paper describes the formulation of a two-phase downward vertical flow pressure drop model which is not limited by the ''no-slip'' homogeneous flow assumptions in most previously published models. By using different correlations for mist, bubble, and slug flow, improved pressure drop calculations result, which in turn improve temperature predictions. The paper describes how the model handles temperature predictions differently in the single and two-phase steam flow situations. The paper also describes special features in the model to account for layered soil properties, soil dry out, cyclic injection, coupling heat losses, and reflux boiling in wet annuli. Two examples problems are presented which illustrate some of these features.

Galate, J.W.; Mitchell, R.F.

1985-03-01T23:59:59.000Z

430

Selenide isotope generator for the Galileo Mission: copper/water axially-grooved heat pipe topical report  

SciTech Connect

This report presents a summary of the major accomplishments for the development, fabrication, and testing of axially-grooved copper/water heat pipes for Selenide Isotopic Generator (SIG) applications. The early development consisted of chemical, physical, and analytical studies to define an axially-grooved tube geometry that could be successfully fabricated and provide the desired long term (up to seven years) performance is presented. Heat pipe fabrication procedures, measured performance and accelerated life testing of heat pipes S/Ns AL-5 and LT-57 conducted at B and K Engineering are discussed. S/N AL-5 was the first axially-grooved copper/water heat pipe that was fabricated with the new internal coating process for cupric oxide (CuO) and the cleaning and water preparation methods developed by Battelle Columbus Laboratories. Heat pipe S/N LT-57 was fabricated along with sixty other axially-grooved heat pipes allocated for life testing at Teledyne Energy Systems. As of June 25, 1979, heat pipes S/Ns AL-5 and LT-57 have been accelerated life tested for 13,310 and 6,292 respectively, at a nominal operating temperature of 225/sup 0/C without any signs of thermal performance degradation. (TFD)

Strazza, N.P.

1979-06-30T23:59:59.000Z

431

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

Science Conference Proceedings (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

432

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

433

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

Science Conference Proceedings (OSTI)

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

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

1990-05-01T23:59:59.000Z

434

Heat flow in the Oregon Cascade Range and its correlation with regional gravity, Curie point depths, and geology  

Science Conference Proceedings (OSTI)

Heat flow measurements from several deep wells (up to 2,500 m deep), as well as extensive new data from industry exploration efforts in the Breitenbush and the Santiam Pass-Belknap/Foley areas are described. The heat flow is about 100 mW m{sup {minus}2} in the High Cascade Range and at the eastern edge of the Western Cascade Range, and about 40-50 mW m{sup {minus}2} to the west in the outer arc block of the subduction zone. The gravity field in the Cascade Range has characteristics that can be closely related to the heat flow pattern. The relationship may be causal, and to examine the relationship in more detail, earlier two-dimensional modeling is extended to three dimensions. Consideration of the effects of a midcrustal density anomaly, such as might be associated with a region with at least areas of partial melt, as two major consequences. The first of these is that a high-frequency gravity gradient near the Western Cascade Range/High Cascade Range boundary is explained. Second, the negative gravity anomaly associated with the northeast/southwest striking regional Bouguer gravity anomaly associated with the north edge of the Blue Mountains becomes continuous across the Cascade Range with a similar feature along the north side of the Klamath Mountains. The correlation, or lack thereof, of the heat flow, depth to Curie point, gravity field, crustal electrical resistivity, crustal seismic velocity, and geology in the High/Western Cascade Ranges is summarized.

Blackwell, D.D.; Steele, J.L. (Southern Methodist Univ., Dallas, TX (USA)); Frohme, M.K. (Memphis State Univ., TN (USA)); Murphey, C.F. (Union Pacific Resources, Arlington, TX (USA)); Priest, G.R.; Black, G.L. (Dept. of Geological and Mineral Industries, Portland, OR (USA))

1990-11-10T23:59:59.000Z

435

Triple loop heat exchanger for an absorption refrigeration system  

DOE Patents (OSTI)

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

Reimann, Robert C. (Lafayette, NY)

1984-01-01T23:59:59.000Z

436

PC-based fluid and heat transfer analyzer for two-phase flow in pipes.  

E-Print Network (OSTI)

??Modeling the simultaneous flow of gas and liquid or two-phase gas-liquid flow in pipes is a key aspect in petroleum production. These models can enhance… (more)

Afonja, Gbolahan.

2006-01-01T23:59:59.000Z

437

Cooling of X-ray Emitting Gas by Heat Conduction in the Center of Cooling Flow Clusters  

E-Print Network (OSTI)

We study the possibility that a large fraction of the gas at temperatures of ? 10 7 K in cooling flow clusters cools by heat conduction to lower temperatures, rather than by radiative cooling. We argue that this process, when incorporated into the so-called “moderate cooling flow model”, where the effective age of the intracluster medium is much lower than the age of the cluster, reduces substantially the expected X-ray luminosity from gas residing at temperatures of ? 10 7 K. In this model, the radiative mass cooling rate of gas at ? 10 7 K inferred from X-ray observations, which is heat conduction is regulated by reconnection between the magnetic field lines in cold ( ? 10 4 K) clouds and the field lines in the intracluster medium. A narrow conduction front is formed, which, despite the relatively low temperature, allows efficient heat conduction from the hot ICM to the cold clouds. The reconnection between the field lines in cold clouds and those in the intracluster medium occurs only when the magnetic field in the ICM is strong enough. This occurs only in the very inner regions of cooling flow clusters, at r ? 10 ? 30 kpc. The large ratio of the number of H? photons to the number of cooling hydrogen atoms is explained by this scenario. 1.

Noam Soker; L. Blanton; Craig L. Sarazin; Chandra Fellow

2003-01-01T23:59:59.000Z

438

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

439

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. (Cleveland, OH); Moore, Paul B. (Fedhaven, FL)

1977-01-01T23:59:59.000Z

440

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

E-Print Network (OSTI)

Analysed at NBVC Electricity Tariff Natural Gas Tariff Nopurchase any electricity under the tariff. This is simplytheir electricity and heat requirements, the tariffs they

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

2004-01-01T23:59:59.000Z

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441

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

DOE Green Energy (OSTI)

The effect of vortex generators on the mass (heat) transfer from the ribbed passage of a two pass turbine blade coolant channel is investigated with the intent of optimizing the vortex generator geometry so that significant enhancements in mass/heat transfer can be achieved. In the experimental configuration considered, ribs are mounted on two opposite walls; all four walls along each pass are active and have mass transfer from their surfaces but the ribs are non-participating. Mass transfer measurements, in the form of Sherwood number ratios, are made along the centerline and in selected inter-rib modules. Results are presented for Reynolds number in the range of 5,000 to 40,000, pitch to rib height ratios of 10.5 and 21, and vortex generator-rib spacing to rib height ratios of 0.55, and 1.5. Centerline and spanwise averaged Sherwood number ratios are presented along with contours of the Sherwood number ratios. Results indicate that the vortex generators induce substantial increases in the local mass transfer rates, particularly along the side walls, and modest increases in the average mass transfer rates. The vortex generators have the effect of making the inter-rib profiles along the ribbed walls more uniform. Along the side walls, horse-shoe vortices that characterize the vortex generator wake are associated with significant mass transfer enhancements. The wake effects and the levels of enhancement decrease somewhat with increasing Reynolds number and decreasing pitch.

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

1995-12-31T23:59:59.000Z

442