National Library of Energy BETA

Sample records for a2 approximate heat

  1. A mixed formulation for the direct approximation -weighted controls for the linear heat

    E-Print Network [OSTI]

    Boyer, Edmond

    A mixed formulation for the direct approximation of L2 -weighted controls for the linear heat of null controls for the linear heat equa- tion. The goal is to compute approximations of controls-Cara & M¨unch, Strong convergence approximations of null controls for the 1D heat equation, 2013], a so

  2. Numerical approximation of bang-bang controls for the heat equation: an optimal design approach

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Numerical approximation of bang-bang controls for the heat equation: an optimal design approach approximation of null controls of minimal L -norm for the linear heat equation with a bounded potential. Both the internal and boundary controllability problem of a linear heat equation with a bounded potential. Let us

  3. Numerical approximation of bang-bang controls for the heat equation: an optimal design approach

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Numerical approximation of bang-bang controls for the heat equation: an optimal design approach computation of null controls of minimal L -norm for the linear heat equation with a bounded potential. Both and boundary controllability cases, are described within this new approach. Keywords: Linear heat equation

  4. Numerical approximation of null controls for the heat equation through transmutation

    E-Print Network [OSTI]

    Sart, Remi

    Numerical approximation of null controls for the heat equation through transmutation Arnaud M to the ill-posedness of the backward heat problem. The controls of minimal L2 -norm are characterized the control of a heat process in terms of the corresponding control of the associated wave process, by means

  5. A 2-Approximation Algorithms for Genome Rearrangements by Reversals and Transpositions 1

    E-Print Network [OSTI]

    Gu, Qianping

    A 2-Approximation Algorithms for Genome Rearrangements by Reversals and Transpositions 1 Qian of Texas at Dallas, Richardson, TX 75083 U.S.A. Keywords: Sorting of permutations, genome rearrangements: Recently, a new approach to analyze genomes evolving was proposed which is based on comparison of gene

  6. Heat Transfer -1 A satellite in space orbits the sun. The satellite can be approximated as a flat plate with

    E-Print Network [OSTI]

    Virginia Tech

    Heat Transfer - 1 A satellite in space orbits the sun. The satellite can be approximated as a flat plate with dimensions and properties given below. (a) Calculate the solar heat flux (W/m2 is at a distance where the solar heat flux (as defined above) is 500 W/m2 , and the flat plate is oriented

  7. Excess Specific Heat of Ptfe and Pctfe at Low Temperatures: Approximation Details

    E-Print Network [OSTI]

    Bogdanova, Nina B

    2008-01-01

    Approximation of the previously estimated excess specific heat C^{excess}/T^{5} of two fluoropolymers, PTFE and PCTFE, is presented using Orthonormal Polynomial Expansion Method (OPEM). The new type of weighting functions in OPEM involves the experimental errors in every point of the studied thermal characteristic. The investigated temperature dependence of the function C^{excess}/T^{5} is described in the whole temperature ranges 0.4\\div8 K and 2.5\\div7 K respectively for PTFE and PCTFE as well as in two subintervals (0.4\\div2) K, (2.5\\div8) K for PTFE. Numerical results of the deviations between the given C^{excess}/T^{5} data and their approximating values are given. The usual polynomial coefficients obtained by orthonormal ones in our OPEM approach and the calculated in every point absolute, relative and specific sensitivities of the studied thermal characteristic are proposed too. The approximation parameters of this type thermal characteristic are shown in Figures and Tables.

  8. Modelling and numerical approximation of a 2.5D set of equations for mesoscale atmospheric processes

    E-Print Network [OSTI]

    Kalise, Dante

    2011-01-01

    The set of 3D inviscid primitive equations for the atmosphere is dimensionally reduced by a Discontinuous Galerkin discretization in one horizontal direction. The resulting model is a 2D system of balance laws where with a source term depending on the layering procedure and the choice of coupling fluxes, which is established in terms of upwind considerations. The "2.5D" system is discretized via a WENO-TVD scheme based in a flux limiter centered approach. We study four tests cases related to atmospheric phenomena to analyze the physical validity of the model.

  9. A 2-D Test Problem for CFD Modeling Heat Transfer in Spent Fuel Transfer Cask Neutron Shields

    SciTech Connect (OSTI)

    Zigh, Ghani; Solis, Jorge; Fort, James A.

    2011-01-14

    In the United States, commercial spent nuclear fuel is typically moved from spent fuel pools to outdoor dry storage pads within a transfer cask system that provides radiation shielding to protect personnel and the surrounding environment. The transfer casks are cylindrical steel enclosures with integral gamma and neutron radiation shields. Since the transfer cask system must be passively cooled, decay heat removal from spent nuclear fuel canister is limited by the rate of heat transfer through the cask components, and natural convection from the transfer cask surface. The primary mode of heat transfer within the transfer cask system is conduction, but some cask designs incorporate a liquid neutron shield tank surrounding the transfer cask structural shell. In these systems, accurate prediction of natural convection within the neutron shield tank is an important part of assessing the overall thermal performance of the transfer cask system. The large-scale geometry of the neutron shield tank, which is typically an annulus approximately 2 meters in diameter but only 5-10 cm in thickness, and the relatively small scale velocities (typically less than 5 cm/s) represent a wide range of spatial and temporal scales that contribute to making this a challenging problem for computational fluid dynamics (CFD) modeling. Relevant experimental data at these scales are not available in the literature, but some recent modeling studies offer insights into numerical issues and solutions; however, the geometries in these studies, and for the experimental data in the literature at smaller scales, all have large annular gaps that are not prototypic of the transfer cask neutron shield. This paper presents results for a simple 2-D problem that is an effective numerical analog for the neutron shield application. Because it is 2-D, solutions can be obtained relatively quickly allowing a comparison and assessment of sensitivity to model parameter changes. Turbulence models are considered as well as the tradeoff between steady state and transient solutions. Solutions are compared for two commercial CFD codes, FLUENT and STAR-CCM+. The results can be used to provide input to the CFD Best Practices for this application. Following study results for the 2-D test problem, a comparison of simulation results is provided for a high Rayleigh number experiment with large annular gap. Because the geometry of this validation is significantly different from the neutron shield, and due to the critical nature of this application, the argument is made for new experiments at representative scales

  10. Numerical modeling of a 2K J-T heat exchanger used in Fermilab Vertical Test Stand VTS-1

    SciTech Connect (OSTI)

    Gupta, Prabhat Kumar; Rabehl, Roger

    2014-07-01

    Fermilab Vertical Test Stand-1 (VTS-1) is in operation since 2007 for testing the superconducting RF cavities at 2 K. This test stand has single layer coiled finned tubes heat exchanger before J-T valve. A finite difference based thermal model has been developed in Engineering Equation Solver (EES) to study its thermal performance during filling and refilling to maintain the constant liquid level of test stand. The model is also useful to predict its performance under other various operating conditions and will be useful to design the similar kind of heat exchanger for future needs. Present paper discusses the different operational modes of this heat exchanger and its thermal characteristics under these operational modes. Results of this model have also been compared with the experimental data gathered from the VTS-1 heat exchanger and they are in good agreement with the present model.

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

    E-Print Network [OSTI]

    Danforth, Chris

    . Examples of natural convection cells occurring in engineering devices include solar water heaters, nu into the system while the upper half is cooled by an equal-but- opposite heat flux out of the system. Water between landmass and an adjacent body of water; mantle convection of the Earth's asthenosphere which

  12. APPROXIMATION NONSYMMETRIC

    E-Print Network [OSTI]

    Chuan, Toh Kim

    for the Degree of Doctor of Philosophy by Kim Chuan Toh August 1996 c fl Kim Chuan Toh 1996 ALL RIGHTS RESERVED #12; MATRIX APPROXIMATION PROBLEMS AND NONSYMMETRIC ITERATIVE METHODS Kim Chuan Toh, Ph.D. Cornell

  13. Tips: Heat Pumps | Department of Energy

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

    climates, providing up to three times more heat than the energy they use. Today's heat pump can reduce your electricity use for heating by approximately 50% compared to...

  14. Multivariate approximation Robert Schaback

    E-Print Network [OSTI]

    Schaback, Robert

    Multivariate approximation Robert Schaback July 30, 2013 1 Synonyms Approximation by functions Approximations of functions are multivariate, if they replace functions of n 2 variables defined on a domain. 4 Overview Multivariate approximation is an extension of Approximation Theory and Approximation

  15. Fast Approximate Convex Decomposition 

    E-Print Network [OSTI]

    Ghosh, Mukulika

    2012-10-19

    Approximate convex decomposition (ACD) is a technique that partitions an input object into "approximately convex" components. Decomposition into approximately convex pieces is both more efficient to compute than exact ...

  16. Approximate Information Theory

    E-Print Network [OSTI]

    Penny, Will

    Approximate Inference Will Penny Information Theory Information Entropy Kullback-Liebler Divergence Approximate Inference Will Penny 31st March 2011 #12;Approximate Inference Will Penny Information Theory Will Penny Information Theory Information Entropy Kullback-Liebler Divergence Gaussians Asymmetry

  17. Heat pipe array heat exchanger

    DOE Patents [OSTI]

    Reimann, Robert C. (Lafayette, NY)

    1987-08-25

    A heat pipe arrangement for exchanging heat between two different temperature fluids. The heat pipe arrangement is in a ounterflow relationship to increase the efficiency of the coupling of the heat from a heat source to a heat sink.

  18. Approximations non-recursively

    E-Print Network [OSTI]

    Ábrahám, Erika

    ) * x Regard non-recursively de#12;ned approximations fact 0 = nx -> bot fact 1 = nx -> if x else fact 0 (x 1) #3; x fact 2 = nx -> if x fact of fact should satisfy the de#12;ning equation fact = nx -> if x

  19. Hybrid Heat Pump Design and Application 

    E-Print Network [OSTI]

    Wagner, J. R.; Koebberman, W. F.

    1985-01-01

    The Hybrid Heat Pump (HHP) converts industrial waste heat into process steam. Waste heat at temperatures as low as approximately 200°F can be used. Steam output covers a range between 12,000 Ib/h and 50,000 Ib/h, depending on the application...

  20. Total Space Heating Water Heating Cook-

    Gasoline and Diesel Fuel Update (EIA)

    Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ... 1,602 1,397...

  1. Total Space Heating Water Heating Cook-

    Gasoline and Diesel Fuel Update (EIA)

    Energy Consumption Survey: Energy End-Use Consumption Tables Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All...

  2. Total Space Heating Water Heating Cook-

    Gasoline and Diesel Fuel Update (EIA)

    Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings ... 2,037...

  3. Total Space Heating Water Heating Cook-

    Gasoline and Diesel Fuel Update (EIA)

    Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ... 1,870 1,276...

  4. Total Space Heating Water Heating Cook-

    Gasoline and Diesel Fuel Update (EIA)

    Tables Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings ... 636 580 46 1 Q 114.0...

  5. Susanville District Heating District Heating Low Temperature...

    Open Energy Info (EERE)

    Susanville District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Susanville District Heating District Heating Low Temperature...

  6. Approximation Algorithms for Covering Problems

    E-Print Network [OSTI]

    Koufogiannakis, Christos

    2009-01-01

    1.3.1 Sequential Algorithms . . . . . . . . . . . . .Distributed 2-approximation algorithm for CMIP 2 (Alg.2 Sequential Algorithm 2.1 The Greedy Algorithm for Monotone

  7. Approximate circuits for increased reliability

    DOE Patents [OSTI]

    Hamlet, Jason R.; Mayo, Jackson R.

    2015-12-22

    Embodiments of the invention describe a Boolean circuit having a voter circuit and a plurality of approximate circuits each based, at least in part, on a reference circuit. The approximate circuits are each to generate one or more output signals based on values of received input signals. The voter circuit is to receive the one or more output signals generated by each of the approximate circuits, and is to output one or more signals corresponding to a majority value of the received signals. At least some of the approximate circuits are to generate an output value different than the reference circuit for one or more input signal values; however, for each possible input signal value, the majority values of the one or more output signals generated by the approximate circuits and received by the voter circuit correspond to output signal result values of the reference circuit.

  8. Acoustically enhanced heat exchange and drying apparatus

    DOE Patents [OSTI]

    Bramlette, T.T.; Keller, J.O.

    1987-07-10

    A heat transfer drying apparatus includes an acoustically augmented heat transfer chamber for receiving material to be dried. The chamber includes a first heat transfer gas inlet, a second heat transfer gas inlet, a material inlet, and a gas outlet which also serves as a dried material and gas outlet. A non-pulsing first heat transfer gas source provides a first drying gas to the acoustically augmented heat transfer chamber through the first heat transfer gas inlet. A valveless, continuous second heat transfer gas source provides a second drying gas to the acoustically augmented heat transfer chamber through the second heat transfer gas inlet. The second drying gas also generates acoustic waves which bring about acoustical coupling with the gases in the acoustically augmented heat transfer chamber. The second drying gas itself oscillates at an acoustic frequency of approximately 180 Hz due to fluid mechanical motion in the gas. The oscillations of the second heat transfer gas coupled to the first heat transfer gas in the acoustically augmented heat transfer chamber enhance heat and mass transfer by convection within the chamber. 3 figs.

  9. Approximate Graph Products Marc Hellmutha

    E-Print Network [OSTI]

    Stadler, Peter F.

    Approximate Graph Products Marc Hellmutha , Wilfried Imrichb , Werner Kl¨ocklb , Peter F. Stadlera or fingers) can vary independently of other traits, or Email addresses: marc@bioinf.uni-leipzig.de (Marc

  10. APPROXIMATELY UNITARILY EQUIVALENT MORPHISMS AND ...

    E-Print Network [OSTI]

    2010-07-28

    ?(a) = diag(a(x)1,...,a(xk)), then we say that ? and ? are approximately unitarily ... Mr?1(C(X)) and a unital ?-homomorphism µ : C(X) ? Mr(C(X)) with finite.

  11. Heat collector

    DOE Patents [OSTI]

    Merrigan, M.A.

    1981-06-29

    A heat collector and method suitable for efficiently and cheaply collecting solar and other thermal energy are provided. The collector employs a heat pipe in a gravity-assist mode and is not evacuated. The collector has many advantages, some of which include ease of assembly, reduced structural stresses on the heat pipe enclosure, and a low total materials cost requirement. Natural convective forces drive the collector, which after startup operates entirely passively due in part to differences in molecular weights of gaseous components within the collector.

  12. Heat collector

    DOE Patents [OSTI]

    Merrigan, Michael A. (Santa Cruz, NM)

    1984-01-01

    A heat collector and method suitable for efficiently and cheaply collecting solar and other thermal energy are provided. The collector employs a heat pipe in a gravity-assist mode and is not evacuated. The collector has many advantages, some of which include ease of assembly, reduced structural stresses on the heat pipe enclosure, and a low total materials cost requirement. Natural convective forces drive the collector, which after startup operates entirely passively due in part to differences in molecular weights of gaseous components within the collector.

  13. Corrosive resistant heat exchanger

    DOE Patents [OSTI]

    Richlen, Scott L. (Annandale, VA)

    1989-01-01

    A corrosive and errosive resistant heat exchanger which recovers heat from a contaminated heat stream. The heat exchanger utilizes a boundary layer of innocuous gas, which is continuously replenished, to protect the heat exchanger surface from the hot contaminated gas. The innocuous gas is conveyed through ducts or perforations in the heat exchanger wall. Heat from the heat stream is transferred by radiation to the heat exchanger wall. Heat is removed from the outer heat exchanger wall by a heat recovery medium.

  14. The validity of the Background Field Approximation

    E-Print Network [OSTI]

    R. Parentani

    1997-10-10

    In the absence of a tractable theory of quantum gravity, quantum matter field effects have been so far computed by treating gravity at the Background Field Approximation. The principle aim of this paper is to investigate the validity of this approximation which is not specific to gravity. To this end, for reasons of simplicity and clarity, we shall compare the descriptions of thermal processes induced by constant acceleration (i.e. the Unruh effect) in four dynamical frameworks. In this problem, the position of the ``heavy'' accelerated system plays the role of gravity. In the first framework, the trajectory is treated at the BFA: it is given from the outset and unaffected by radiative processes. In the second one, recoil effects induced by these emission processes are taken into account by describing the system's position by WKB wave functions. In the third one, the accelerated system is described by second quantized fields and in the fourth one, gravity is turned on. It is most interesting to see when and why transitions amplitudes evaluated in different frameworks but describing the same process do agree. It is indeed this comparison that determines the validity of the BFA. It is also interesting to notice that the abandonment of the BFA delivers new physical insights concerning the processes. For instance, in the fourth framework, the ``recoils'' of gravity show that the acceleration horizon area acts as an entropy in delivering heat to accelerated systems.

  15. Joule heating at high latitudes

    SciTech Connect (OSTI)

    Foster, J.C.; St.-Maurice, J.; Abreu, V.J.

    1983-06-01

    High latitude Joule heating has been calculated from simultaneous observations of the electric field magnitude and the Pedersen conductivity calculated from individual measurements of the ion drift velocity and particle precipitation observed over the lifetime of the AE-C satellite. The data were sorted by latitude, local time, hemisphere, season, and Kp index and separate averages of the electric field magnitude, Pedersen conductivity and Joule heating was prepared. Conductivities produced by an averaged seasonal solar illumination were included with those calculated from the particle precipitation. We found that high-latitude Joule heating occurs in a roughly oval pattern and consists of three distinct heating regions: the dayside cleft, the region of sunward convection at dawn and dusk, and the midnight sector. On the average, heating in the cleft and dawn-dusk regions contributes the largest heat input. There is no apparent difference between hemispheres for similar seasons. Hemisphere averaged Joule heating at equinox amounts to approximately 25 GW for Kp = 1 conditions, 85G GW for Kp = 4, and varies linearly as a function of Kp. The Joule heat input is 50% greater during the summer than during winter primarily due to the increased conductivity caused by solar production.

  16. ABSORPTION HEAT PUMP IN THE DISTRICT HEATING

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    #12;ABSORPTION HEAT PUMP IN THE DISTRICT HEATING PLANT Dr.sc.ing. Agnese Lickrastina M.Sc. Normunds European Heat Pump Summit 2013, Nuremberg, 15-16.10.2013 · Riga District Heating company · Operation of the DH plant Imanta · Selection of the heat pump/chiller · Operation of the heat pump/chiller · Summary

  17. Planning numerical approximations Richard Power

    E-Print Network [OSTI]

    Williams, Sandra

    Planning numerical approximations Richard Power Sandra Williams 21st September 2009 #12;Table proportions (e.g., more than a quarter, 25.9 per cent) Proportions are a convenient well-defined subproblem Common in factual discourse (e.g., newspaper articles) Important for generating from data (but neglected

  18. Approximate model checking of stochastic hybrid systems , J.-P. Katoen

    E-Print Network [OSTI]

    Abate, Alessandro

    -room heating system. 1 Introduction Stochastic hybrid systems are a broad and widely applicable classApproximate model checking of stochastic hybrid systems A. Abate , J.-P. Katoen , J. Lygeros , and M. Prandini§ Abstract A method for approximate model checking of stochastic hybrid systems

  19. Attachment A2

    Office of Environmental Management (EM)

    A2 GEOLOGIC REPOSITORY Waste Isolation Pilot Plant Hazardous Waste Permit October 2013 (This page intentionally blank) Waste Isolation Pilot Plant Hazardous Waste Permit October...

  20. Bayonet heat exchangers in heat-assisted Stirling heat pump

    SciTech Connect (OSTI)

    Yagyu, S.; Fukuyama, Y.; Morikawa, T.; Isshiki, N.; Satoh, I.; Corey, J.; Fellows, C.

    1998-07-01

    The Multi-Temperature Heat Supply System is a research project creating a city energy system with lower environmental load. This system consists of a gas-fueled internal combustion engine and a heat-assisted Stirling heat pump utilizing shaft power and thermal power in a combination of several cylinders. The heat pump is mainly driven by engine shaft power and is partially assisted by thermal power from engine exhaust heat source. Since this heat pump is operated by proportioning the two energy sources to match the characteristics of the driving engine, the system is expected to produce cooling and heating water at high COP. This paper describes heat exchanger development in the project to develop a heat-assisted Stirling heat pump. The heat pump employs the Bayonet type heat exchangers (BHX Type I) for supplying cold and hot water and (BHX Type II) for absorbing exhaust heat from the driving engine. The heat exchanger design concepts are presented and their heat transfer and flow loss characteristics in oscillating gas flow are investigated. The main concern in the BHX Type I is an improvement of gas side heat transfer and the spirally finned tubes were applied to gas side of the heat exchanger. For the BHX Type II, internal heat transfer characteristics are the main concern. Shell-and-tube type heat exchangers are widely used in Stirling machines. However, since brazing is applied to the many tubes for their manufacturing processes, it is very difficult to change flow passages to optimize heat transfer and loss characteristics once they have been made. The challenge was to enhance heat transfer on the gas side to make a highly efficient heat exchanger with fewer parts. It is shown that the Bayonet type heat exchanger can have good performance comparable to conventional heat exchangers.

  1. NUMERICAL NULL CONTROLLABILITY OF THE HEAT EQUATION THROUGH A LEAST SQUARES AND VARIATIONAL APPROACH

    E-Print Network [OSTI]

    NUMERICAL NULL CONTROLLABILITY OF THE HEAT EQUATION THROUGH A LEAST SQUARES AND VARIATIONAL of null controls for the heat equation. The goal is to compute an approximation of controls that drives-space dimensional case. Key Words. Heat equation, Null controllability, Numerical approximation, Variational ap

  2. Heating System Specification Specification of Heating System

    E-Print Network [OSTI]

    Day, Nancy

    Appendix A Heating System Specification /* Specification of Heating System (loosely based */ requestHeat : Room ­? bool; 306 #12; APPENDIX A. HEATING SYSTEM SPECIFICATION 307 /* user inputs */ living --- HEATERâ??ACTIVE --- ACTIVATINGâ??HEATER --- HEATERâ??RUNNING ; #12; APPENDIX A. HEATING SYSTEM SPECIFICATION

  3. SMALL PARTICLE HEAT EXCHANGERS

    E-Print Network [OSTI]

    Hunt, A.J.

    2011-01-01

    The Small Particle Heat Exchange Receiver (SPHER) for Solarof the small particle heat exchange receiver (or SPHER), asabsorption process, the heat exchange to the gas, the choice

  4. Heat pump system

    DOE Patents [OSTI]

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

    1982-01-01

    An air heating and cooling system for a building includes an expansion-type refrigeration circuit and a heat engine. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The heat engine includes a heat rejection circuit having a source of rejected heat and a primary heat exchanger connected to the source of rejected heat. The heat rejection circuit also includes an evaporator in heat exchange relation with the primary heat exchanger, a heat engine indoor heat exchanger, and a heat engine outdoor heat exchanger. The indoor heat exchangers are disposed in series air flow relationship, with the heat engine indoor heat exchanger being disposed downstream from the refrigeration circuit indoor heat exchanger. The outdoor heat exchangers are also disposed in series air flow relationship, with the heat engine outdoor heat exchanger disposed downstream from the refrigeration circuit outdoor heat exchanger. A common fluid is used in both of the indoor heat exchanges and in both of the outdoor heat exchangers. In a first embodiment, the heat engine is a Rankine cycle engine. In a second embodiment, the heat engine is a non-Rankine cycle engine.

  5. Water and Space Heating Heat Pumps 

    E-Print Network [OSTI]

    Kessler, A. F.

    1985-01-01

    This paper discusses the design and operation of the Trane Weathertron III Heat Pump Water Heating System and includes a comparison of features and performance to other domestic water heating systems. Domestic water is generally provided through...

  6. Industrial Waste Heat Recovery Using Heat Pipes 

    E-Print Network [OSTI]

    Ruch, M. A.

    1981-01-01

    For almost a decade now, heat pipes with secondary finned surfaces have been utilized in counter flow heat exchangers to recover sensible energy from industrial exhaust gases. Over 3,000 such heat exchangers are now in service, recovering...

  7. Linear Value Function Approximation Linear Models

    E-Print Network [OSTI]

    Parr, Ronald

    Linear Value Function Approximation and Linear Models Ronald Parr Duke University Joint work terminology · Various forms of linear value function approximation · Linear approximate model formulation #12;Outline · Introduce terminology · Various forms of linear value function approximation · Linear

  8. LUBRICATION APPROXIMATION WITH PRESCRIBED NONZERO CONTACT ANGLE

    E-Print Network [OSTI]

    Otto, Felix

    LUBRICATION APPROXIMATION WITH PRESCRIBED NONZERO CONTACT ANGLE Felix Otto Department--time existence for a weak solution s(t; x) â?? 0 of the lubrication approximation @ t s + @ x (s @ 3 x s) = 0 in fs will later motivate the way we construct approximate solutions for the lubrication approximation we are going

  9. Heating systems for heating subsurface formations

    DOE Patents [OSTI]

    Nguyen, Scott Vinh (Houston, TX); Vinegar, Harold J. (Bellaire, TX)

    2011-04-26

    Methods and systems for heating a subsurface formation are described herein. A heating system for a subsurface formation includes a sealed conduit positioned in an opening in the formation and a heat source. The sealed conduit includes a heat transfer fluid. The heat source provides heat to a portion of the sealed conduit to change phase of the heat transfer fluid from a liquid to a vapor. The vapor in the sealed conduit rises in the sealed conduit, condenses to transfer heat to the formation and returns to the conduit portion as a liquid.

  10. Heat transfer and heat exchangers reference handbook

    SciTech Connect (OSTI)

    Not Available

    1991-01-15

    The purpose of this handbook is to provide Rocky Flats personnel with an understanding of the basic concepts of heat transfer and the operation of heat exchangers.

  11. Integrated heat pump and heat storage system

    SciTech Connect (OSTI)

    Katz, A.

    1983-09-13

    An integrated heat pump and heat storage system is disclosed comprising a heat pump, a first conduit for supplying return air from an enclosure to the heat pump, a second conduit for supplying heated air from the heat pump to the enclosure, heat storage apparatus. A first damper is operative in a first orientation to permit return air from the enclosure to enter the first conduit and to prevent return air from passing through the heat storage apparatus and operative in a second orientation to cause return air to pass through the heat storage apparatus for being heated thereby before entering the first conduit. A second damper is operative in a first orientation to cause heated air from the second conduit to pass through the heat storage apparatus for giving up a portion of its heat for storage and operative in a second orientation to prevent heated air from the second conduit from passing through the heat storage apparatus and to permit the heated air from the second conduit to reach the enclosure. The heat storage apparatus may comprise phase change materials.

  12. Approximation Algorithms and Heuristics for a 2-depot, Heterogeneous Hamiltonian Path Problem 

    E-Print Network [OSTI]

    Doshi, Riddhi Rajeev

    2011-10-21

    Various civil and military applications of UAVs, or ground robots, require a set of vehicles to monitor a group of targets. Routing problems naturally arise in this setting where the operators of the vehicles have to plan the paths suitably in order...

  13. Fabrication and heating rate study of microscopic surface electrode ion traps

    E-Print Network [OSTI]

    Daniilidis, N.

    We report heating rate measurements in a microfabricated gold-on-sapphire surface electrode ion trap with a trapping height of approximately 240 ?m. Using the Doppler recooling method, we characterize the trap heating rates ...

  14. Dual source heat pump

    DOE Patents [OSTI]

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

    1982-01-01

    What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid provides energy for defrosting the second heat exchanger when operating in the air source mode and also provides a alternate source of heat.

  15. Technical Report NREL/TP-7A2-46190

    E-Print Network [OSTI]

    Technical Report NREL/TP-7A2-46190 July 2009 Market Assessment of Biomass Gasification Technical Report NREL/TP-7A2-46190 July 2009 Market Assessment of Biomass Gasification and Combustion of gasification and direct combustion technologies that utilize solid biomass to generate heat, power, or combined

  16. An approximation technique for jet impingement flow

    SciTech Connect (OSTI)

    Najafi, Mahmoud; Fincher, Donald; Rahni, Taeibi; Javadi, KH.; Massah, H.

    2015-03-10

    The analytical approximate solution of a non-linear jet impingement flow model will be demonstrated. We will show that this is an improvement over the series approximation obtained via the Adomian decomposition method, which is itself, a powerful method for analysing non-linear differential equations. The results of these approximations will be compared to the Runge-Kutta approximation in order to demonstrate their validity.

  17. Heat release analysis of engine pressure data

    SciTech Connect (OSTI)

    Gatowski, J.A.; Balles, E.N.; Chun, K.M.; Nelson, F.E.; Ekchian, J.A.; Heywood, J.B.

    1984-01-01

    In analyzing the processes inside the cylinder of an internal combustion engine, the principal diagnostic at the experimenter's disposal is a measured time history of the cylinder pressure. This paper develops, tests, and applies a heat release analysis procedure that maintains simplicity while including the effects of heat transfer, crevice flows and fuel injection. The heat release model uses a one zone description of the cylinder contents with thermodynamic properties represented by a linear approximation. Applications of the analysis to a single-cylinder spark-ignition engine, a special square cross-section visualization spark-ignition engine, and a direct-injection stratified charge engine are presented.

  18. Low rank approximations of matrices and tensors

    E-Print Network [OSTI]

    Friedland, Shmuel

    Low rank approximations of matrices and tensors S. Friedland, V. Mehrmann, A. Miedlar and M, 2008 S. Friedland, V. Mehrmann, A. Miedlar and M. Nkengla Low rank approximations of matrices and tensors #12;Overview S. Friedland, V. Mehrmann, A. Miedlar and M. Nkengla Low rank approximations

  19. Mpemba effect, Newton cooling law and heat transfer equation

    E-Print Network [OSTI]

    Vladan Pankovic; Darko V. Kapor

    2012-12-11

    In this work we suggest a simple theoretical solution of the Mpemba effect in full agreement with known experimental data. This solution follows simply as an especial approximation (linearization) of the usual heat (transfer) equation, precisely linearization of the second derivation of the space part of the temperature function (as it is well-known Newton cooling law can be considered as the effective approximation of the heat (transfer) equation for constant space part of the temperature function).

  20. Multiple source heat pump

    DOE Patents [OSTI]

    Ecker, Amir L. (Duncanville, TX)

    1983-01-01

    A heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating a fluid in heat exchange relationship with a refrigerant fluid, at least three refrigerant heat exchangers, one for effecting heat exchange with the fluid, a second for effecting heat exchange with a heat exchange fluid, and a third for effecting heat exchange with ambient air; a compressor for compressing the refrigerant; at least one throttling valve connected at the inlet side of a heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circuit and pump for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and directional flow of refrigerant therethrough for selecting a particular mode of operation. Also disclosed are a variety of embodiments, modes of operation, and schematics therefor.

  1. Heat Plan DenmarkHeat Plan Denmark Anders Dyrelundy

    E-Print Network [OSTI]

    efficient use of renewable energy in district heating · individual heat pumps solar heating and wood pellets· individual heat pumps, solar heating and wood pellets 6Risø International Energy Conference 2009Heat Plan

  2. Heat Exchangers for Solar Water Heating Systems | Department...

    Energy Savers [EERE]

    Heat Exchangers for Solar Water Heating Systems Heat Exchangers for Solar Water Heating Systems Image of a heat exchanger. | Photo from iStockphoto.com Image of a heat exchanger. |...

  3. Heat-Of-Reaction Chemical Heat Pumps--Possible Configurations 

    E-Print Network [OSTI]

    Kirol, L. D.

    1986-01-01

    Chemical heat pumps utilize working fluids which undergo reversible chemical changes. Mechanically driven reactive heat pump cycles or, alternatively, heat driven heat pumps in which either heat engine or heat pump ...

  4. Introduction to Heat Exchangers

    E-Print Network [OSTI]

    Heller, Barbara

    . Since, the effectiveness can be written in terms of heat capacitance rate [W/K], C, and change in temperature [K], . The heat capacitance rate is defined in terms of mass flow rate [kg/s], , and specific heat: ! ! ! " # = ! ! "# ! ! ! - ! ! ! ! ! ! = ! !! ! ! ! ! = ! ! ! ! ! - ! ! ! ! ! "# ! ! ! - ! ! ! ! ! ! = ! ! ! ! ! - ! ! ! ! ! "# ! ! ! - ! ! ! ! ! Heat%Capacitance%Rate % ! = ! !! ! ! Heat%Capacitance%Rate%[W % ! = ! ! ! ! ! ! ! = ! ! !! ! ! ! max

  5. Waste Heat Recovery – Submerged Arc Furnaces (SAF) 

    E-Print Network [OSTI]

    O'Brien, T.

    2008-01-01

    designed consumes power and fuel that yields an energy efficiency of approximately 40% (Total Btu’s required to reduce to elemental form/ Btu Input). The vast majority of heat is lost to the atmosphere or cooling water system. The furnaces can be modified...

  6. Heat Pump for High School Heat Recovery 

    E-Print Network [OSTI]

    Huang, K.; Wang, H.; Zhou, X.

    2006-01-01

    The heat pump system used for recycling and reusing waste heat in s high school bathroom was minutely analyzed in its coefficient of performance, onetime utilization ratio of energy, economic property and so on. The results showed that this system...

  7. Pagosa Springs District Heating District Heating Low Temperature...

    Open Energy Info (EERE)

    Pagosa Springs District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Pagosa Springs District Heating District Heating Low...

  8. City of Klamath Falls District Heating District Heating Low Temperatur...

    Open Energy Info (EERE)

    City of Klamath Falls District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name City of Klamath Falls District Heating District Heating...

  9. San Bernardino District Heating District Heating Low Temperature...

    Open Energy Info (EERE)

    San Bernardino District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name San Bernardino District Heating District Heating Low...

  10. Philip District Heating District Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Philip District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Philip District Heating District Heating Low Temperature Geothermal...

  11. Kethcum District Heating District Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Kethcum District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Kethcum District Heating District Heating Low Temperature Geothermal...

  12. Boise City Geothermal District Heating District Heating Low Temperatur...

    Open Energy Info (EERE)

    Boise City Geothermal District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Boise City Geothermal District Heating District Heating...

  13. Midland District Heating District Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Midland District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Midland District Heating District Heating Low Temperature Geothermal...

  14. Northeast Home Heating Oil Reserve System Heating Oil, PIA Office...

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

    Northeast Home Heating Oil Reserve System Heating Oil, PIA Office of Fossil Energy Headquaters Northeast Home Heating Oil Reserve System Heating Oil, PIA Office of Fossil Energy...

  15. SMALL PARTICLE HEAT EXCHANGERS

    E-Print Network [OSTI]

    Hunt, A.J.

    2011-01-01

    heat exchangers. These types of heat exchangers have limitedheat exchanger to solar collection systems that utilize linear trough- typenon-solar heat exchangers. These may be of the type used to

  16. Concentrating solar heat collector

    SciTech Connect (OSTI)

    Fattor, A.P.

    1980-09-23

    A heat storage unit is integrated with a collection unit providing a heat supply in off-sun times, and includes movable insulation means arranged to provide insulation during off-sun times for the heat storage unit.

  17. Absorption heat pump system

    DOE Patents [OSTI]

    Grossman, G.

    1982-06-16

    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  18. Absorption heat pump system

    DOE Patents [OSTI]

    Grossman, Gershon (Oak Ridge, TN)

    1984-01-01

    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  19. Locating Heat Recovery Opportunities 

    E-Print Network [OSTI]

    Waterland, A. F.

    1981-01-01

    Basic concepts of heat recovery are defined as they apply to the industrial community. Methods for locating, ranking, and developing heat recovery opportunities are presented and explained. The needs for useful heat 'sinks' are emphasized as equal...

  20. HEAT STORAGE AND ADVECTION IN THE NORTH PACIFIC OCEAN

    E-Print Network [OSTI]

    Luther, Douglas S.

    HEAT STORAGE AND ADVECTION IN THE NORTH PACIFIC OCEAN A DISSERTATION SUBMITTED TO THE GRADUATE maintaining the seasonal heat storage in the 0 to 250 meter surface layer of the North Pacific Ocean. Approximately 140,000 bathy- thermograph observations taken in the Pacific Ocean from 10° South latitude to 70

  1. Woven heat exchanger

    DOE Patents [OSTI]

    Piscitella, R.R.

    1984-07-16

    This invention relates to a heat exchanger for waste heat recovery from high temperature industrial exhaust streams. In a woven ceramic heat exchanger using the basic tube-in-shell design, each heat exchanger consisting of tube sheets and tube, is woven separately. Individual heat exchangers are assembled in cross-flow configuration. Each heat exchanger is woven from high temperature ceramic fiber, the warp is continuous from tube to tube sheet providing a smooth transition and unitized construction.

  2. Total Space Heat-

    Gasoline and Diesel Fuel Update (EIA)

    Revised: December, 2008 Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other All Buildings...

  3. Total Space Heat-

    Gasoline and Diesel Fuel Update (EIA)

    Released: September, 2008 Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other All Buildings*...

  4. Geothermal Heat Pumps

    Broader source: Energy.gov [DOE]

    Geothermal heat pumps are expensive to install but pay for themselves over time in reduced heating and cooling costs. Find out if one is right for your home.

  5. HEATING AND COOLING PROTOSTELLAR DISKS

    SciTech Connect (OSTI)

    Hirose, S. [Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, 3173-25 Showamachi, Kanazawa-ku, Yokohama, Kanagawa 236-0001 (Japan); Turner, N. J., E-mail: shirose@jamstec.go.jp, E-mail: neal.turner@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2011-05-10

    We examine heating and cooling in protostellar disks using three-dimensional radiation-MHD calculations of a patch of the Solar nebula at 1 AU, employing the shearing-box and flux-limited radiation diffusion approximations. The disk atmosphere is ionized by stellar X-rays, well coupled to magnetic fields, and sustains a turbulent accretion flow driven by magnetorotational instability, while the interior is resistive and magnetically dead. The turbulent layers are heated by absorbing the light from the central star and by dissipating the magnetic fields. They are optically thin to their own radiation and cool inefficiently. The optically thick interior in contrast is heated only weakly, by re-emission from the atmosphere. The interior is colder than a classical viscous model and isothermal. The magnetic fields support an extended atmosphere that absorbs the starlight 1.5 times higher than the hydrostatic viscous model. The disk thickness thus measures not the internal temperature, but the magnetic field strength. Fluctuations in the fields move the starlight-absorbing surface up and down. The height ranges between 13% and 24% of the radius over timescales of several orbits, with implications for infrared variability. The fields are buoyant, so the accretion heating occurs higher in the atmosphere than the stresses. The heating is localized around current sheets, caused by magnetorotational instability at lower elevations and by Parker instability at higher elevations. Gas in the sheets is heated above the stellar irradiation temperature, even though accretion is much less than irradiation power when volume averaged. The hot optically thin current sheets might be detectable through their line emission.

  6. Helically coiled tube heat exchanger

    SciTech Connect (OSTI)

    Harris, A.M.

    1981-08-18

    In a heat exchanger such as a steam generator for a nuclear reactor, two or more bundles of helically coiled tubes are arranged in series with the tubes in each bundle integrally continuing through the tube bundles arranged in series therewith. Pitch values for the tubing in any pair of tube bundles, taken transverse to the path of the reactor coolant flow about the tubes, are selected as a ratio of two unequal integers to permit efficient operation of each tube bundle while maintaining the various tube bundles of the heat exchanger within a compact envelope. Preferably, the helix angle and tube pitch parallel to the path of coolant flow are constant for all tubes in a single bundle so that the tubes are of approximately the same length within each bundle.

  7. Near approximations via general ordered topological spaces

    E-Print Network [OSTI]

    M. Abo-Elhamayel

    2014-12-27

    Rough set theory is a new mathematical approach to imperfect knowledge. The notion of rough sets is generalized by using an arbitrary binary relation on attribute values in information systems, instead of the trivial equality relation. The topology induced by binary relations is used to generalize the basic rough set concepts. This paper studies near approximation via general ordered topological approximation spaces which may be viewed as a generalization of the study of near approximation from the topological view. The basic concepts of some increasing (decreasing) near approximations, increasing (decreasing) near boundary regions and increasing (decreasing) near accuracy were introduced and sufficiently illustrated. Moreover, proved results, implications and add examples.

  8. APPROXIMATION OF ELECTROMAGNETIC FIELDS: PART I ...

    E-Print Network [OSTI]

    2003-08-06

    Opérateurs, 1984, Commissariat `a l'Energie Atomique, Masson, Paris. [10] J. DOUGLAS, JR., J. E. SANTOS, AND D. SHEEN, Approximation of scalar waves in ...

  9. Lower bounds for approximate factorizations via semidefinite ...

    E-Print Network [OSTI]

    ABSTRACT The problem of approximately factoring a real or complex multivariate polynomial f seeks minimal perturbations ? f to the coefficients of the input ...

  10. Optimization Online - Probabilistic optimization via approximate p ...

    E-Print Network [OSTI]

    W. van vAckooij

    2015-05-27

    May 27, 2015 ... Probabilistic optimization via approximate p-efficient points and bundle methods. W. van vAckooij(wim.van-ackooij ***at*** edf.fr )

  11. Approximations by Orthonormal Mapped Chebyshev Functions for ...

    E-Print Network [OSTI]

    2014-03-12

    a School of Mathematical Science, Xiamen University, 361005 Xiamen, China .... suitable mapping can be used to approximate functions on the whole line R (cf.

  12. Heat release characteristics of stratified-charge rotary engines

    SciTech Connect (OSTI)

    Dimpelfeld, P.; Humke, A.

    1987-01-01

    A computer program for calculating heat release rates from stratified-charge rotary engines is described. Important aspects of the program include calculation of equilibrium combustion product properties, treatment of both liquid and gas phase fuel in the chamber, heat transfer, leakage past side and apex seals, and crevice effects. Heat release rates are presented from 580 and 70 Series rotary engines. Combustion in the 580 Series engine exhibits two distinct phases. The first phase occurs rapidly, with a duration of approximately 40 shaft degrees. The second phase of combustion proceeds more slowly, with a duration of approximately 70 shaft degrees. Three phases of combustion are observed for the 70 Series engine.

  13. A Coupled AtmosphereOcean Radiative Transfer System Using the Analytic Four-Stream Approximation

    E-Print Network [OSTI]

    Liou, K. N.

    of the ocean. Shortwave radiation from the sun contributes most of the heat fluxes that penetrate the airA Coupled Atmosphere­Ocean Radiative Transfer System Using the Analytic Four-Stream Approximation WEI-LIANG LEE AND K. N. LIOU Department of Atmospheric and Oceanic Sciences, University of California

  14. Direct fired heat exchanger

    DOE Patents [OSTI]

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

    1986-01-01

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

  15. Woven heat exchanger

    DOE Patents [OSTI]

    Piscitella, Roger R. (Idaho Falls, ID)

    1987-01-01

    In a woven ceramic heat exchanger using the basic tube-in-shell design, each heat exchanger consisting of tube sheets and tube, is woven separately. Individual heat exchangers are assembled in cross-flow configuration. Each heat exchanger is woven from high temperature ceramic fiber, the warp is continuous from tube to tube sheet providing a smooth transition and unitized construction.

  16. Rotary magnetic heat pump

    DOE Patents [OSTI]

    Kirol, L.D.

    1987-02-11

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

  17. Rotary magnetic heat pump

    DOE Patents [OSTI]

    Kirol, Lance D. (Shelly, ID)

    1988-01-01

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

  18. Mass and Heat Recovery 

    E-Print Network [OSTI]

    Hindawai, S. M.

    2010-01-01

    In the last few years heat recovery was under spot and in air conditioning fields usually we use heat recovery by different types of heat exchangers. The heat exchanging between the exhaust air from the building with the fresh air to the building...

  19. Approximate Euclidean Ramsey theorems Adrian Dumitrescu

    E-Print Network [OSTI]

    Dumitrescu, Adrian

    Approximate Euclidean Ramsey theorems Adrian Dumitrescu October 27, 2010 Abstract According condition is needed in this case. Keywords: Euclidean Ramsey theory, approximate arithmetic progression result of Ramsey from 1930: Theorem 1 (Ramsey [24]). Let p q, and r be positive integers

  20. APPROXIMATE SIMULATION RELATIONS FOR HYBRID SYSTEMS 1

    E-Print Network [OSTI]

    Pappas, George J.

    . Pappas Department of Electrical and Systems Engineering University of Pennsylvania Philadelphia, PA been introduced as a powerful tool for the approximation of discrete and continuous systems systems approximation. An example of application in the context of safety verification is shown. Keywords

  1. APPROXIMATION RESULTS FOR REFLECTIONLESS JACOBI MATRICES

    E-Print Network [OSTI]

    Remling, Christian

    APPROXIMATION RESULTS FOR REFLECTIONLESS JACOBI MATRICES ALEXEI POLTORATSKI AND CHRISTIAN REMLING Abstract. We study spaces of reflectionless Jacobi matrices. The main theme is the following type of question: Given a reflectionless Jacobi matrix, is it possible to approximate it by other reflection- less

  2. Heat Treating Apparatus

    DOE Patents [OSTI]

    De Saro, Robert (Annandale, NJ); Bateman, Willis (Sutton Colfield, GB)

    2002-09-10

    Apparatus for heat treating a heat treatable material including a housing having an upper opening for receiving a heat treatable material at a first temperature, a lower opening, and a chamber therebetween for heating the heat treatable material to a second temperature higher than the first temperature as the heat treatable material moves through the chamber from the upper to the lower opening. A gas supply assembly is operatively engaged to the housing at the lower opening, and includes a source of gas, a gas delivery assembly for delivering the gas through a plurality of pathways into the housing in countercurrent flow to movement of the heat treatable material, whereby the heat treatable material passes through the lower opening at the second temperature, and a control assembly for controlling conditions within the chamber to enable the heat treatable material to reach the second temperature and pass through the lower opening at the second temperature as a heated material.

  3. Integrated heat pump system

    SciTech Connect (OSTI)

    Reedy, W.R.

    1988-03-01

    An integrated heat pump and hot water system is described that includes: a heat pump having an indoor heat exchanger and an outdoor heat exchanger that are selectively connected to the suction line and the discharge line respectively of a compressor by a flow reversing means, and to each other by a liquid line having an expansion device mounted therein, whereby heating and cooling is provided to an indoor comfort zone by cycling the flow reversing means, a refrigerant to water heat exchanger having a hot water flow circuit in heat transfer relation with a first refrigerant condensing circuit and a second refrigerant evaporating circuit, a connection mounted in the liquid between the indoor heat exchanger and the expansion device, control means for regulating the flow of refrigerant through the refrigerant to water heat exchanger to selectively transfer heat into and out of the hot water flow circuit.

  4. Thulium-170 heat source

    DOE Patents [OSTI]

    Walter, Carl E. (Pleasanton, CA); Van Konynenburg, Richard (Livermore, CA); VanSant, James H. (Tracy, CA)

    1992-01-01

    An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

  5. An improved proximity force approximation for electrostatics

    E-Print Network [OSTI]

    C. D. Fosco; F. C. Lombardo; F. D. Mazzitelli

    2012-04-23

    A quite straightforward approximation for the electrostatic interaction between two perfectly conducting surfaces suggests itself when the distance between them is much smaller than the characteristic lengths associated to their shapes. Indeed, in the so called "proximity force approximation" the electrostatic force is evaluated by first dividing each surface into a set of small flat patches, and then adding up the forces due two opposite pairs, the contribution of which are approximated as due to pairs of parallel planes. This approximation has been widely and successfully applied to different contexts, ranging from nuclear physics to Casimir effect calculations. We present here an improvement on this approximation, based on a derivative expansion for the electrostatic energy contained between the surfaces. The results obtained could be useful to discuss the geometric dependence of the electrostatic force, and also as a convenient benchmark for numerical analyses of the tip-sample electrostatic interaction in atomic force microscopes.

  6. Approximate error conjugation gradient minimization methods

    DOE Patents [OSTI]

    Kallman, Jeffrey S

    2013-05-21

    In one embodiment, a method includes selecting a subset of rays from a set of all rays to use in an error calculation for a constrained conjugate gradient minimization problem, calculating an approximate error using the subset of rays, and calculating a minimum in a conjugate gradient direction based on the approximate error. In another embodiment, a system includes a processor for executing logic, logic for selecting a subset of rays from a set of all rays to use in an error calculation for a constrained conjugate gradient minimization problem, logic for calculating an approximate error using the subset of rays, and logic for calculating a minimum in a conjugate gradient direction based on the approximate error. In other embodiments, computer program products, methods, and systems are described capable of using approximate error in constrained conjugate gradient minimization problems.

  7. Thermoelectric heat exchange element

    DOE Patents [OSTI]

    Callas, James J. (Peoria, IL); Taher, Mahmoud A. (Peoria, IL)

    2007-08-14

    A thermoelectric heat exchange module includes a first substrate including a heat receptive side and a heat donative side and a series of undulatory pleats. The module may also include a thermoelectric material layer having a ZT value of 1.0 or more disposed on at least one of the heat receptive side and the heat donative side, and an electrical contact may be in electrical communication with the thermoelectric material layer.

  8. Phase-lag heat conduction: decay rates for limit problems and well-posedness

    E-Print Network [OSTI]

    Racke, Reinhard

    Phase-lag heat conduction: decay rates for limit problems and well-posedness Karin Borgmeyer, Ram approximations to dual-phase-lag and three-phase-lag heat conduction equations. However, for several limit cases analysis is rigorously proved exemplarily. 1 Introduction It is well known that Fourier's heat conduction

  9. Numerical null controllability of the 1D heat equation: dual methods

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Numerical null controllability of the 1D heat equation: dual methods Enrique Fern for the 1D heat equation. The goal is to compute a control that drives (a numerical approximation of and efficiency. Keywords: one-dimensional heat equation, null controllability, finite element methods, dual meth

  10. Numerical exact controllability of the 1D heat equation: Carleman weights and duality

    E-Print Network [OSTI]

    Numerical exact controllability of the 1D heat equation: Carleman weights and duality Enrique Fern for the 1D heat equation. The goal is to compute a control that drives (a numerical approximation of [11], where primal methods were considered. Keywords: Heat equation, null controllability, numerical

  11. Numerical null controllability of semi-linear 1-D heat equations: fixed point, least squares and

    E-Print Network [OSTI]

    Sart, Remi

    Numerical null controllability of semi-linear 1-D heat equations: fixed point, least squares with the numerical computation of distributed null controls for semi- linear 1D heat equations, in the sublinear in [Fernandez-Cara & Zuazua, Null and approximate controllability for weakly blowing up semi-linear heat

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

    E-Print Network [OSTI]

    Boyer, Edmond

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

  13. Wave-mechanics and the adhesion approximation

    E-Print Network [OSTI]

    C. J. Short; P. Coles

    2006-11-22

    The dynamical equations describing the evolution of a self-gravitating fluid of cold dark matter (CDM) can be written in the form of a Schrodinger equation coupled to a Poisson equation describing Newtonian gravity. It has recently been shown that, in the quasi-linear regime, the Schrodinger equation can be reduced to the exactly solvable free-particle Schrodinger equation. The free-particle Schrodinger equation forms the basis of a new approximation scheme -the free-particle approximation - that is capable of evolving cosmological density perturbations into the quasi-linear regime. The free-particle approximation is essentially an alternative to the adhesion model in which the artificial viscosity term in Burgers' equation is replaced by a non-linear term known as the quantum pressure. Simple one-dimensional tests of the free-particle method have yielded encouraging results. In this paper we comprehensively test the free-particle approximation in a more cosmologically relevant scenario by appealing to an N-body simulation. We compare our results with those obtained from two established methods: the linearized fluid approach and the Zeldovich approximation. We find that the free-particle approximation comprehensively out-performs both of these approximation schemes in all tests carried out and thus provides another useful analytical tool for studying structure formation on cosmological scales.

  14. Accuracy of Nonlinear Approximations in Spheroidal Collapse --- Why are Zel'dovich-type approximations so good? ---

    E-Print Network [OSTI]

    Ayako Yoshisato; Takahiko Matsubara; Masahiro Morikawa

    1997-08-11

    Among various analytic approximations for the growth of density fluctuations in the expanding Universe, Zel'dovich approximation and its extensions in Lagrangian scheme are known to be accurate even in mildly non-linear regime. The aim of this paper is to investigate the reason why these Zel'dovich-type approximations work accurately beyond the linear regime from the following two points of view: (1) Dimensionality of the system and (2) the Lagrangian scheme on which the Zel'dovich approximation is grounded. In order to examine the dimensionality, we introduce a model with spheroidal mass distribution. In order to examine the Lagrangian scheme, we introduce the Pad\\'e approximation in Eulerian scheme. We clarify which of these aspects supports the unusual accuracy of the Zel'dovich-type approximations. We also give an implication for more accurate approximation method beyond the Zel'dovich-type approximations.

  15. Heat transfer system

    DOE Patents [OSTI]

    Not Available

    1980-03-07

    A heat transfer system for a nuclear reactor is described. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.

  16. Heat transfer system

    DOE Patents [OSTI]

    McGuire, Joseph C. (Richland, WA)

    1982-01-01

    A heat transfer system for a nuclear reactor. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.

  17. Wound tube heat exchanger

    DOE Patents [OSTI]

    Ecker, Amir L. (Duncanville, TX)

    1983-01-01

    What is disclosed is a wound tube heat exchanger in which a plurality of tubes having flattened areas are held contiguous adjacent flattened areas of tubes by a plurality of windings to give a double walled heat exchanger. The plurality of windings serve as a plurality of effective force vectors holding the conduits contiguous heat conducting walls of another conduit and result in highly efficient heat transfer. The resulting heat exchange bundle is economical and can be coiled into the desired shape. Also disclosed are specific embodiments such as the one in which the tubes are expanded against their windings after being coiled to insure highly efficient heat transfer.

  18. Harmonic Wavelet Transform and Image Approximation

    E-Print Network [OSTI]

    Zhang, Zhihua; Saito, Naoki

    2010-01-01

    DOI 10.1007/s10851-010-0202-x Harmonic Wavelet Transform andwe approximate f by a harmonic function u such that thebanks. We call this the Harmonic Wavelet Transform (HWT).

  19. Approximate inference in Gaussian graphical models

    E-Print Network [OSTI]

    Malioutov, Dmitry M., 1981-

    2008-01-01

    The focus of this thesis is approximate inference in Gaussian graphical models. A graphical model is a family of probability distributions in which the structure of interactions among the random variables is captured by a ...

  20. A fresh look at the adhesion approximation

    E-Print Network [OSTI]

    Thomas Buchert

    1997-11-04

    I report on a systematic derivation of the phenomenological ``adhesion approximation'' from gravitational instability together with a brief evaluation of the related status of analytical modeling of large-scale structure.

  1. Energy-efficient approximate computation in Topaz

    E-Print Network [OSTI]

    Achour, Sara

    2015-01-01

    The increasing prominence of energy consumption as a first-order concern in contemporary computing systems has motivated the design of energy-efficient approximate computing platforms. These computing platforms feature ...

  2. Updated: June 21, 2010 Diophantine approximation,

    E-Print Network [OSTI]

    Waldschmidt, Michel

    Updated: June 21, 2010 Diophantine approximation, irrationality and transcendence Michel] Chap. 3. See also [1] Chap. III. References [1] S. Lang, Introduction to transcendental numbers transcendants, Springer-Verlag, Berlin, 1974. Lecture Notes in Mathematics, Vol. 402. http

  3. Optimization in Geometric Graphs: Complexity and Approximation 

    E-Print Network [OSTI]

    Kahruman-Anderoglu, Sera

    2011-02-22

    We consider several related problems arising in geometric graphs. In particular, we investigate the computational complexity and approximability properties of several optimization problems in unit ball graphs and develop ...

  4. Signal approximation using the bilinear transform

    E-Print Network [OSTI]

    Venkataraman, Archana, Ph. D. Massachusetts Institute of Technology

    2007-01-01

    This thesis explores the approximation properties of a unique basis expansion. The expansion implements a nonlinear frequency warping between a continuous-time signal and its discrete-time representation according to the ...

  5. Polymer state approximations of Schroedinger wave functions

    E-Print Network [OSTI]

    Klaus Fredenhagen; Felix Reszewski

    2006-08-25

    It is shown how states of a quantum mechanical particle in the Schroedinger representation can be approximated by states in the so-called polymer representation. The result may shed some light on the semiclassical limit of loop quantum gravity.

  6. An improved proximity force approximation for electrostatics

    SciTech Connect (OSTI)

    Fosco, Cesar D.; Instituto Balseiro, Universidad Nacional de Cuyo, R8402AGP Bariloche ; Lombardo, Fernando C.; IFIBA ; Mazzitelli, Francisco D.

    2012-08-15

    A quite straightforward approximation for the electrostatic interaction between two perfectly conducting surfaces suggests itself when the distance between them is much smaller than the characteristic lengths associated with their shapes. Indeed, in the so called 'proximity force approximation' the electrostatic force is evaluated by first dividing each surface into a set of small flat patches, and then adding up the forces due two opposite pairs, the contributions of which are approximated as due to pairs of parallel planes. This approximation has been widely and successfully applied in different contexts, ranging from nuclear physics to Casimir effect calculations. We present here an improvement on this approximation, based on a derivative expansion for the electrostatic energy contained between the surfaces. The results obtained could be useful for discussing the geometric dependence of the electrostatic force, and also as a convenient benchmark for numerical analyses of the tip-sample electrostatic interaction in atomic force microscopes. - Highlights: Black-Right-Pointing-Pointer The proximity force approximation (PFA) has been widely used in different areas. Black-Right-Pointing-Pointer The PFA can be improved using a derivative expansion in the shape of the surfaces. Black-Right-Pointing-Pointer We use the improved PFA to compute electrostatic forces between conductors. Black-Right-Pointing-Pointer The results can be used as an analytic benchmark for numerical calculations in AFM. Black-Right-Pointing-Pointer Insight is provided for people who use the PFA to compute nuclear and Casimir forces.

  7. Consolidated Electric Cooperative- Heat Pump and Water Heating Rebates

    Office of Energy Efficiency and Renewable Energy (EERE)

    Consolidated Electric Cooperative provides rebates to residential customers who install electric water heaters, dual-fuel heating system or geothermal heat pumps. A dual-fuel heating systems...

  8. Total Space Heat-

    Gasoline and Diesel Fuel Update (EIA)

    Survey: Energy End-Use Consumption Tables Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other...

  9. HEAT TRANSFER FLUIDS

    E-Print Network [OSTI]

    Lenert, Andrej

    2012-01-01

    The choice of heat transfer fluids has significant effects on the performance, cost, and reliability of solar thermal systems. In this chapter, we evaluate existing heat transfer fluids such as oils and molten salts based ...

  10. Fusion heating technology

    SciTech Connect (OSTI)

    Cole, A.J.

    1982-06-01

    John Lawson established the criterion that in order to produce more energy from fusion than is necessary to heat the plasma and replenish the radiation losses, a minimum value for both the product of plasma density and confinement time t, and the temperature must be achieved. There are two types of plasma heating: neutral beam and electromagnetic wave heating. A neutral beam system is shown. Main development work on negative ion beamlines has focused on the difficult problem of the production of high current sources. The development of a 30 keV-1 ampere multisecond source module is close to being accomplished. In electromagnetic heating, the launcher, which provides the means of coupling the power to the plasma, is most important. The status of heating development is reviewed. Electron cyclotron resonance heating (ECRH), lower hybrid heating (HHH), and ion cyclotron resonance heating (ICRH) are reviewed.

  11. Photovoltaic roof heat flux

    E-Print Network [OSTI]

    Samady, Mezhgan Frishta

    2011-01-01

    designs (relatively) Photovoltaic Solar P a n e l AtmosphereCALIFORNIA, SAN DIEGO Photovoltaic Roof Heat Flux A ThesisABSTRACT OF T H E THESIS Photovoltaic Roof Heat Flux by

  12. Photovoltaic roof heat flux

    E-Print Network [OSTI]

    Samady, Mezhgan Frishta

    2011-01-01

    influence on the heat transfer as the radiation. Since thethe heat transfer analysis, the difference of net radiationheat transfer involved i n this project were conduction, convection and radiation.

  13. Abrasion resistant heat pipe

    DOE Patents [OSTI]

    Ernst, D.M.

    1984-10-23

    A specially constructed heat pipe is described for use in fluidized bed combustors. Two distinct coatings are spray coated onto a heat pipe casing constructed of low thermal expansion metal, each coating serving a different purpose. The first coating forms aluminum oxide to prevent hydrogen permeation into the heat pipe casing, and the second coating contains stabilized zirconium oxide to provide abrasion resistance while not substantially affecting the heat transfer characteristics of the system.

  14. Abrasion resistant heat pipe

    DOE Patents [OSTI]

    Ernst, Donald M. (Leola, PA)

    1984-10-23

    A specially constructed heat pipe for use in fluidized bed combustors. Two distinct coatings are spray coated onto a heat pipe casing constructed of low thermal expansion metal, each coating serving a different purpose. The first coating forms aluminum oxide to prevent hydrogen permeation into the heat pipe casing, and the second coating contains stabilized zirconium oxide to provide abrasion resistance while not substantially affecting the heat transfer characteristics of the system.

  15. Solar heat receiver

    DOE Patents [OSTI]

    Hunt, A.J.; Hansen, L.J.; Evans, D.B.

    1982-09-29

    A receiver is described for converting solar energy to heat a gas to temperatures from 700 to 900/sup 0/C. The receiver is formed to minimize impingement of radiation on the walls and to provide maximum heating at and near the entry of the gas exit. Also, the receiver is formed to provide controlled movement of the gas to be heated to minimize wall temperatures. The receiver is designed for use with gas containing fine heat absorbing particles, such as carbon particles.

  16. MA HEAT Loan Overview

    Broader source: Energy.gov [DOE]

    Presents information on the success of Massachusetts's HEAT loan offerings and how the financing tool is funded.

  17. Solar heat receiver

    DOE Patents [OSTI]

    Hunt, Arlon J. (Oakland, CA); Hansen, Leif J. (Berkeley, CA); Evans, David B. (Orinda, CA)

    1985-01-01

    A receiver for converting solar energy to heat a gas to temperatures from 700.degree.-900.degree. C. The receiver is formed to minimize impingement of radiation on the walls and to provide maximum heating at and near the entry of the gas exit. Also, the receiver is formed to provide controlled movement of the gas to be heated to minimize wall temperatures. The receiver is designed for use with gas containing fine heat absorbing particles, such as carbon particles.

  18. Geothermal Heat Pump Basics

    Broader source: Energy.gov [DOE]

    Geothermal heat pumps use the constant temperature of the earth as an exchange medium for heat. Although many parts of the country experience seasonal temperature extremes—from scorching heat in the summer to sub-zero cold in the winter—the ground a few feet below the earth's surface remains at a relatively constant temperature.

  19. Liquid heat capacity lasers

    DOE Patents [OSTI]

    Comaskey, Brian J. (Walnut Creek, CA); Scheibner, Karl F. (Tracy, CA); Ault, Earl R. (Livermore, CA)

    2007-05-01

    The heat capacity laser concept is extended to systems in which the heat capacity lasing media is a liquid. The laser active liquid is circulated from a reservoir (where the bulk of the media and hence waste heat resides) through a channel so configured for both optical pumping of the media for gain and for light amplification from the resulting gain.

  20. Pioneering Heat Pump Project

    Broader source: Energy.gov [DOE]

    Project objectives: To install and monitor an innovative WaterFurnace geothermal system that is technologically advanced and evolving; To generate hot water heating from a heat pump that uses non-ozone depleting refrigerant CO2. To demonstrate the energy efficiency of this system ground source heat pump system.

  1. Heat Transfer Guest Editorial

    E-Print Network [OSTI]

    Kandlikar, Satish

    Journal of Heat Transfer Guest Editorial We are indeed delighted in bringing out this special issue was showcased in diverse areas such as traditional heat and mass transfer, lab-on-chip, sensors, biomedical applica- tions, micromixers, fuel cells, and microdevices. Selected papers in the field of heat transfer

  2. A corrosive resistant heat exchanger

    DOE Patents [OSTI]

    Richlen, S.L.

    1987-08-10

    A corrosive and erosive resistant heat exchanger which recovers heat from a contaminated heat stream. The heat exchanger utilizes a boundary layer of innocuous gas, which is continuously replenished, to protect the heat exchanger surface from the hot contaminated gas. The innocuous gas is pumped through ducts or perforations in the heat exchanger wall. Heat from the heat stream is transferred by radiation to the heat exchanger wall. Heat is removed from the outer heat exchanger wall by a heat recovery medium. 3 figs., 3 tabs.

  3. Heat recovery in building envelopes

    E-Print Network [OSTI]

    Walker, Iain S.; Sherman, Max H.

    2003-01-01

    2003). Infiltration heat recovery – ASHRAE Research ProjectModel for Infiltration Heat Recovery, Proc. 21 st AnnualN ATIONAL L ABORATORY Heat Recovery in Building Envelopes

  4. Heat Recovery in Building Envelopes

    E-Print Network [OSTI]

    Sherman, Max H.; Walker, Iain S.

    2001-01-01

    Model For Infiltration Heat Recovery. Proceedings 21st AivcLBNL 47329 HEAT RECOVERY IN BUILDING ENVELOPES Max H.contribution because of heat recovery within the building

  5. Heat recovery in building envelopes

    E-Print Network [OSTI]

    Walker, Iain S.; Sherman, Max H.

    2003-01-01

    2003). Infiltration heat recovery – ASHRAE Research ProjectModel for Infiltration Heat Recovery, Proc. 21 st AnnualWalker, I.S. (2001). "Heat Recovery in Building Envelopes".

  6. Chemical heat pump

    DOE Patents [OSTI]

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

    1980-01-01

    A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer. The heat pump part of the system heats or cools a house or other structure through a combination of evaporation and absorption or, conversely, condensation and desorption, in a pair of containers. A set of automatic controls change the system for operation during winter and summer months and for daytime and nighttime operation to satisfactorily heat and cool a house during an entire year. The absorber chamber is subjected to solar heating during regeneration cycles and is covered by one or more layers of glass or other transparent material. Daytime home air used for heating the home is passed at appropriate flow rates between the absorber container and the first transparent cover layer in heat transfer relationship in a manner that greatly reduce eddies and resultant heat loss from the absorbant surface to ambient atmosphere.

  7. Heat Transfer Fluids for Solar Water Heating Systems | Department...

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

    Illustration of a solar water heater. Illustration of a solar water heater. Heat-transfer fluids carry heat through solar collectors and a heat exchanger to the heat storage tanks...

  8. Enhanced convective and film boiling heat transfer by surface gas injection

    SciTech Connect (OSTI)

    Duignan, M.R.; Greene, G.A. ); Irvine, T.F., Jr. . Dept. of Mechanical Engineering)

    1992-04-01

    Heat transfer measurements were made for stable film boiling of water over a horizontal, flat stainless steel plate from the minimum film boiling point temperature, T{sub SURFACE} {approximately}500K, to T{sub SURFACE} {approximately}950K. The pressure at the plate was approximately 1 atmosphere and the temperature of the water pool was maintained at saturation. The data were compared to the Berenson film-boiling model, which was developed for minimum film-boiling-point conditions. The model accurately represented the data near the minimum film-boiling point and at the highest temperatures measured, as long it was corrected for the heat transferred by radiation. On the average, the experimental data lay within {plus minus}7% of the model. Measurements of heat transfer were made without film boiling for nitrogen jetting into an overlying pool of water from nine 1-mm- diameter holes, drilled in the heat transfer plate. The heat flux was maintained constant at approximately 26.4 kW/m{sup 2}. For water-pool heights of less than 6cm the heat transfer coefficient deceased linearly with a decrease in heights. Above 6cm the heat transfer coefficient was unaffected. For the entire range of gas velocities measured (0 to 8.5 cm/s), the magnitude of the magnitude of the heat transfer coefficient only changed by approximately 20%. The heat transfer data bound the Konsetov model for turbulent pool heat transfer which was developed for vertical heat transfer surfaces. This agreement suggests that surface orientation may not be important when the gas jets do not locally affect the surface heat transfer. Finally, a database was developed for heat transfer from the plate with both film boiling and gas jetting occurring simultaneously, in a pool of water maintained at its saturation temperature. The effect of passing nitrogen through established film boiling is to increase the heat transfer from that surface. 60 refs.

  9. Enhanced convective and film boiling heat transfer by surface gas injection

    SciTech Connect (OSTI)

    Duignan, M.R.; Greene, G.A.; Irvine, T.F., Jr.

    1992-04-01

    Heat transfer measurements were made for stable film boiling of water over a horizontal, flat stainless steel plate from the minimum film boiling point temperature, T{sub SURFACE} {approximately}500K, to T{sub SURFACE} {approximately}950K. The pressure at the plate was approximately 1 atmosphere and the temperature of the water pool was maintained at saturation. The data were compared to the Berenson film-boiling model, which was developed for minimum film-boiling-point conditions. The model accurately represented the data near the minimum film-boiling point and at the highest temperatures measured, as long it was corrected for the heat transferred by radiation. On the average, the experimental data lay within {plus_minus}7% of the model. Measurements of heat transfer were made without film boiling for nitrogen jetting into an overlying pool of water from nine 1-mm- diameter holes, drilled in the heat transfer plate. The heat flux was maintained constant at approximately 26.4 kW/m{sup 2}. For water-pool heights of less than 6cm the heat transfer coefficient deceased linearly with a decrease in heights. Above 6cm the heat transfer coefficient was unaffected. For the entire range of gas velocities measured [0 to 8.5 cm/s], the magnitude of the magnitude of the heat transfer coefficient only changed by approximately 20%. The heat transfer data bound the Konsetov model for turbulent pool heat transfer which was developed for vertical heat transfer surfaces. This agreement suggests that surface orientation may not be important when the gas jets do not locally affect the surface heat transfer. Finally, a database was developed for heat transfer from the plate with both film boiling and gas jetting occurring simultaneously, in a pool of water maintained at its saturation temperature. The effect of passing nitrogen through established film boiling is to increase the heat transfer from that surface. 60 refs.

  10. Absorption heat pump system

    DOE Patents [OSTI]

    Grossman, Gershon (Oak Ridge, TN); Perez-Blanco, Horacio (Knoxville, TN)

    1984-01-01

    An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

  11. Foundation heat exchangers for residential ground source heat pump systems Numerical modeling and experimental validation

    SciTech Connect (OSTI)

    Xing, Lu [Oklahoma State University; Cullin, James [Oklahoma State University; Spitler, Jeffery [Oklahoma State University; Im, Piljae [ORNL; Fisher, Daniel [Oklahoma State University

    2011-01-01

    A new type of ground heat exchanger that utilizes the excavation often made for basements or foundations has been proposed as an alternative to conventional ground heat exchangers. This article describes a numerical model that can be used to size these foundation heat exchanger (FHX) systems. The numerical model is a two-dimensional finite-volume model that considers a wide variety of factors, such as soil freezing and evapotranspiration. The FHX numerical model is validated with one year of experimental data collected at an experimental house located near Oak Ridge, Tennessee. The model shows good agreement with the experimental data-heat pump entering fluid temperatures typically within 1 C (1.8 F) - with minor discrepancies due to approximations, such as constant moisture content throughout the year, uniform evapotranspiration over the seasons, and lack of ground shading in the model.

  12. Heat pump apparatus

    DOE Patents [OSTI]

    Nelson, Paul A. (Wheaton, IL); Horowitz, Jeffrey S. (Woodridge, IL)

    1983-01-01

    A heat pump apparatus including a compact arrangement of individual tubular reactors containing hydride-dehydride beds in opposite end sections, each pair of beds in each reactor being operable by sequential and coordinated treatment with a plurality of heat transfer fluids in a plurality of processing stages, and first and second valves located adjacent the reactor end sections with rotatable members having multiple ports and associated portions for separating the hydride beds at each of the end sections into groups and for simultaneously directing a plurality of heat transfer fluids to the different groups. As heat is being generated by a group of beds, others are being regenerated so that heat is continuously available for space heating. As each of the processing stages is completed for a hydride bed or group of beds, each valve member is rotated causing the heat transfer fluid for the heat processing stage to be directed to that bed or group of beds. Each of the end sections are arranged to form a closed perimeter and the valve member may be rotated repeatedly about the perimeter to provide a continuous operation. Both valves are driven by a common motor to provide a coordinated treatment of beds in the same reactors. The heat pump apparatus is particularly suitable for the utilization of thermal energy supplied by solar collectors and concentrators but may be used with any source of heat, including a source of low-grade heat.

  13. Active microchannel heat exchanger

    DOE Patents [OSTI]

    Tonkovich, Anna Lee Y. (Pasco, WA) [Pasco, WA; Roberts, Gary L. (West Richland, WA) [West Richland, WA; Call, Charles J. (Pasco, WA) [Pasco, WA; Wegeng, Robert S. (Richland, WA) [Richland, WA; Wang, Yong (Richland, WA) [Richland, WA

    2001-01-01

    The present invention is an active microchannel heat exchanger with an active heat source and with microchannel architecture. The microchannel heat exchanger has (a) an exothermic reaction chamber; (b) an exhaust chamber; and (c) a heat exchanger chamber in thermal contact with the exhaust chamber, wherein (d) heat from the exothermic reaction chamber is convected by an exothermic reaction exhaust through the exhaust chamber and by conduction through a containment wall to the working fluid in the heat exchanger chamber thereby raising a temperature of the working fluid. The invention is particularly useful as a liquid fuel vaporizer and/or a steam generator for fuel cell power systems, and as a heat source for sustaining endothermic chemical reactions and initiating exothermic reactions.

  14. Extending the Eikonal Approximation to Low Energy

    E-Print Network [OSTI]

    Pierre Capel; Tokuro Fukui; Kazuyuki Ogata

    2014-11-21

    E-CDCC and DEA, two eikonal-based reaction models are compared to CDCC at low energy (e.g. 20AMeV) to study their behaviour in the regime at which the eikonal approximation is supposed to fail. We confirm that these models lack the Coulomb deflection of the projectile by the target. We show that a hybrid model, built on the CDCC framework at low angular momenta and the eikonal approximation at larger angular momenta gives a perfect agreement with CDCC. An empirical shift in impact parameter can also be used reliably to simulate this missing Coulomb deflection.

  15. Approximating European Options by Rebate Barrier Options

    E-Print Network [OSTI]

    Song, Qingshuo

    2011-01-01

    When the underlying stock price is a strict local martingale process under an equivalent local martingale measure, Black-Scholes PDE associated with an European option may have multiple solutions. In this paper, we study an approximation for the smallest hedging price of such an European option. Our results show that a class of rebate barrier options can be used for this approximation, when its rebate and barrier are chosen appropriately. An asymptotic convergence rate is also achieved when the knocked-out barrier moves to infinity under suitable conditions.

  16. PERFORMANCE OF A STIRLING ENGINE POWERED HEAT ACTIVATED HEAT PUMP

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    PERFORMANCE OF A STIRLING ENGINE POWERED HEAT ACTIVATED HEAT PUMP W. D. C. Richards and W. L. Auxer General Electric Company Space Division King of Prussia, Pa. ABSTRACT A heat activated heat pump (HAHP by the heat pump effect. The Stirling engine/Rankine cycle refrigeration loop heat pump being developed would

  17. Radiant Heating | Department of Energy

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

    across the room. When radiant heating is located in the floor, it is often called radiant floor heating or simply floor heating. Radiant heating has a number of advantages. It is...

  18. Exact and Approximate REML for Heteroscedastic Regression

    E-Print Network [OSTI]

    Smyth, Gordon K.

    Exact and Approximate REML for Heteroscedastic Regression Gordon K. Smyth Department of Mathematics, the above het- eroscedastic regression model is the most general model of the type considered by LN98 and SV to estimate the het- eroscedastic regression model by way of two coupled generalized linear models

  19. Semicirculant approximations in preconditioners for incompressible flow

    E-Print Network [OSTI]

    be successfully used as an approximate solver of a convection­diffusion problem in the BFB T ­preconditioner ([1 of the convection­ diffusion problem in the BFB T ­preconditioner for the incompressible Navier­ Stokes equations of discrete pressures. The square matrix F here is a discrete convection­diffusion operator. The BFB

  20. The Observer Algorithm for Visibility Approximation

    E-Print Network [OSTI]

    Doherty, Patrick

    , with dif- ferent view ranges and grid cell sizes. By changing the size of the grid cells that the algorithm or more sentries while moving to a goal position. Algorithms for finding a covert paths in the presence of stationary and moving sentries has been devised by [5] [6]. An approximate visibility algorithm was devised

  1. Approximate Inference and Protein-Folding

    E-Print Network [OSTI]

    Weiss, Yair

    Approximate Inference and Protein-Folding Chen Yanover and Yair Weiss School of Computer Science Side-chain prediction is an important subtask in the protein-folding problem. We show that #12;nding algorithms, including a widely used protein-folding software (SCWRL). 1 Introduction Inference in graphical

  2. Notion of p-value Parametric Approximations

    E-Print Network [OSTI]

    Nuel, Gregory

    Notion of p-value Parametric Approximations Power Significance of an Observation in Post-Genomics G, March 7 - 10, 2011 G. NUEL Significance of an Observation in Post-Genomics #12;Notion of p Power of a test ROC and AUC Example with GWAS G. NUEL Significance of an Observation in Post-Genomics

  3. Stochastic Approximation: Sturen in een veranderende wereld

    E-Print Network [OSTI]

    Bhulai, Sandjai

    gedaan door middel van simulaties of experimenten. Twee bekende algoritmes binnen Stochastic Approximation zijn het Robbins- Monro algoritme en het Kiefer-Wolfowitz algoritme. Deze algoritmes benaderen formule is de kleine rekentijd en het gebruik van beperkte geheugenruimte. Echter, het algoritme hangt af

  4. Approximations to the Distributed Activation Energy Model

    E-Print Network [OSTI]

    Approximations to the Distributed Activation Energy Model for Pyrolysis C.P. Please, 1 M.J. Mc, then resubmitted after minor revisions in September 2002. Abstract The Distributed Activation Energy Model (DAEM effective method for estimating kinetic parameters and the distribution of activation energies. Comparison

  5. Updated: May 28, 2010 Diophantine approximation,

    E-Print Network [OSTI]

    Waldschmidt, Michel

    Updated: May 28, 2010 Diophantine approximation, irrationality and transcendence Michel Waldschmidt [3] is: Theorem 121 (Lambert, 1761). For any r Q \\ {0}, the numbers tan r and er are irrational. In particular the number is irrational. The main tool is continued fractions, and the first goal of Lambert

  6. Updated: June 16, 2010 Diophantine approximation,

    E-Print Network [OSTI]

    Waldschmidt, Michel

    Updated: June 16, 2010 Diophantine approximation, irrationality and transcendence Michel. It is known (see for instance [31] p. 25) that if k is a positive integer, if an irrational real number has, 31, 13, 1]. Definition Given a real irrational number , a function = N R>0 is an irrationality

  7. Updated: May 16, 2010 Diophantine approximation,

    E-Print Network [OSTI]

    Waldschmidt, Michel

    Updated: May 16, 2010 Diophantine approximation, irrationality and transcendence Michel Waldschmidt of 2 We first give a geometrical proof of the irrationality of the number 2 = 1, 414 213 562 373 095 rectangle. This proves the irrationality of 2. In algebraic terms, the number x = 1 + 2 satisfies x = 2

  8. Updated: June 1, 2010 Diophantine approximation,

    E-Print Network [OSTI]

    Waldschmidt, Michel

    Updated: June 1, 2010 Diophantine approximation, irrationality and transcendence Michel Waldschmidt on the irrationality of er when r is a non-zero rational number. Next we show how a slight modification implies.1.1 Irrationality of er for r Q If r = a/b is a rational number such that er is also rational, then e|a| is also

  9. Updated: June 23, 2010 Diophantine approximation,

    E-Print Network [OSTI]

    Waldschmidt, Michel

    Updated: June 23, 2010 Diophantine approximation, irrationality and transcendence Michel://www.math.jussieu.fr/ miw/articles/ps/eccm.ps [5] -- , Elliptic functions and transcendence, in Surveys in number theory of and . Schneider's Theorem on the transcendence of j() (corollary 174). 11 Algebraic independence 11.1 Chudnovskii

  10. Optimization of Heat Exchangers

    SciTech Connect (OSTI)

    Ivan Catton

    2010-10-01

    The objective of this research is to develop tools to design and optimize heat exchangers (HE) and compact heat exchangers (CHE) for intermediate loop heat transport systems found in the very high temperature reator (VHTR) and other Generation IV designs by addressing heat transfer surface augmentation and conjugate modeling. To optimize heat exchanger, a fast running model must be created that will allow for multiple designs to be compared quickly. To model a heat exchanger, volume averaging theory, VAT, is used. VAT allows for the conservation of mass, momentum and energy to be solved for point by point in a 3 dimensional computer model of a heat exchanger. The end product of this project is a computer code that can predict an optimal configuration for a heat exchanger given only a few constraints (input fluids, size, cost, etc.). As VAT computer code can be used to model characteristics )pumping power, temperatures, and cost) of heat exchangers more quickly than traditional CFD or experiment, optimization of every geometric parameter simultaneously can be made. Using design of experiment, DOE and genetric algorithms, GE, to optimize the results of the computer code will improve heat exchanger disign.

  11. Heat pump system

    DOE Patents [OSTI]

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

    1983-01-01

    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.

  12. Heat pump system

    DOE Patents [OSTI]

    Swenson, Paul F.; Moore, Paul B.

    1983-06-21

    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.

  13. Policies supporting Heat Pump Technologies

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    Policies supporting Heat Pump Technologies in Canada IEA Heat Pump Workshop London, UK November 13 in the world, with an average of 16,995 kilowatt-hours per annum. #12;Canada's Context for Heat Pumps Impacts avenues: Ground source heat pumps for cold climates (heating and cooling) Reversible air source heat

  14. Radiative heat transfer in 2D Dirac materials

    E-Print Network [OSTI]

    Pablo Rodriguez-Lopez; Wang-Kong Tse; Diego A. R. Dalvit

    2015-02-02

    We compute the radiative heat transfer between two sheets of 2D Dirac materials, including topological Chern insulators and graphene, within the framework of the local approximation for the optical response of these materials. In this approximation, which neglects spatial dispersion, we derive both numerically and analytically the short-distance asymptotic of the near-field heat transfer in these systems, and show that it scales as the inverse of the distance between the two sheets. Finally, we discuss the limitations to the validity of this scaling law imposed by spatial dispersion in 2D Dirac materials.

  15. Fluidized bed heat treating system

    DOE Patents [OSTI]

    Ripley, Edward B; Pfennigwerth, Glenn L

    2014-05-06

    Systems for heat treating materials are presented. The systems typically involve a fluidized bed that contains granulated heat treating material. In some embodiments a fluid, such as an inert gas, is flowed through the granulated heat treating medium, which homogenizes the temperature of the heat treating medium. In some embodiments the fluid may be heated in a heating vessel and flowed into the process chamber where the fluid is then flowed through the granulated heat treating medium. In some embodiments the heat treating material may be liquid or granulated heat treating material and the heat treating material may be circulated through a heating vessel into a process chamber where the heat treating material contacts the material to be heat treated. Microwave energy may be used to provide the source of heat for heat treating systems.

  16. Energy identity of approximate biharmonic maps to Riemannian manifolds and its application

    E-Print Network [OSTI]

    Wang, Changyou

    2011-01-01

    We consider in dimension four weakly convergent sequences of approximate biharmonic maps to a Riemannian manifold with bi-tension fields bounded in $L^p$ for $p>\\frac43$. We prove an energy identity that accounts for the loss of hessian energies by the sum of hessian energies over finitely many nontrivial biharmonic maps on $\\mathbb R^4$. As a corollary, we obtain an energy identity for the heat flow of biharmonic maps at time infinity.

  17. Water-heating dehumidifier

    DOE Patents [OSTI]

    Tomlinson, John J. (Knoxville, TN)

    2006-04-18

    A water-heating dehumidifier includes a refrigerant loop including a compressor, at least one condenser, an expansion device and an evaporator including an evaporator fan. The condenser includes a water inlet and a water outlet for flowing water therethrough or proximate thereto, or is affixed to the tank or immersed into the tank to effect water heating without flowing water. The immersed condenser design includes a self-insulated capillary tube expansion device for simplicity and high efficiency. In a water heating mode air is drawn by the evaporator fan across the evaporator to produce cooled and dehumidified air and heat taken from the air is absorbed by the refrigerant at the evaporator and is pumped to the condenser, where water is heated. When the tank of water heater is full of hot water or a humidistat set point is reached, the water-heating dehumidifier can switch to run as a dehumidifier.

  18. Proceedings of HT2005 2005 ASME Summer Heat Transfer Conference

    E-Print Network [OSTI]

    Aguilar, Guillermo

    Proceedings of HT2005 2005 ASME Summer Heat Transfer Conference July 17-22, 2005, San Francisco absorption and increasing the thickness of the protected region. A 2D finite volume numerical code based interface location density (kg m-3 ) 1 Copyright © 2005 by ASME Proceedings of HT2005 2005 ASME Summer Heat

  19. Heat storage duration

    SciTech Connect (OSTI)

    Balcomb, J.D.

    1981-01-01

    Both the amount and duration of heat storage in massive elements of a passive building are investigated. Data taken for one full winter in the Balcomb solar home are analyzed with the aid of sub-system simulation models. Heat storage duration is tallied into one-day intervals. Heat storage location is discussed and related to overall energy flows. The results are interpreted and conclusions drawn.

  20. SMALL PARTICLE HEAT EXCHANGERS

    E-Print Network [OSTI]

    Hunt, A.J.

    2011-01-01

    by half, the solar collection efficiency will still be insolar thermal electric power program rests on the efficiency,efficiency heat storage systems. This type of hybrid, solar-

  1. Mechanical Compression Heat Pumps 

    E-Print Network [OSTI]

    Apaloo, T. L.; Kawamura, K.; Matsuda, J.

    1986-01-01

    of the compressors which constitute the heart and soul of the system. It will also provide a quick survey of the available types of compressors for heat pumping and some of the industrial processes where simultaneous heating and cooling proceed along parallel..., the real challenge comes process environment, or even for comfort HEAT PUMP APPLICATIONS INPU~ AND OUTPUT UTIUnES (HEAT SOUlCE) (ME0U.4) (API't1CATION) CoofIng, Dehumldilication. L.- -J ~Ing. Hot ...,tolel SIJr-lpIy Chilled ....,oter. Hoi waler...

  2. Waste Heat Recovery

    Office of Environmental Management (EM)

    DRAFT - PRE-DECISIONAL - DRAFT 1 Waste Heat Recovery 1 Technology Assessment 2 Contents 3 1. Introduction to the TechnologySystem ......

  3. Photovoltaic roof heat flux

    E-Print Network [OSTI]

    Samady, Mezhgan Frishta

    2011-01-01

    Effect of building integrated photovoltaics on microclimateof a building's integrated-photovoltaics on heating a n dgaps for building- integrated photovoltaics, Solar Energy

  4. Heat and mass exchanger

    DOE Patents [OSTI]

    Lowenstein, Andrew (Princeton, NJ); Sibilia, Marc J. (Princeton, NJ); Miller, Jeffrey A. (Hopewell, NJ); Tonon, Thomas (Princeton, NJ)

    2011-06-28

    A mass and heat exchanger includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat exchange fluid therethrough, wherein heat transfer occurs between the liquid and the heat exchange fluid.

  5. Heat and mass exchanger

    DOE Patents [OSTI]

    Lowenstein, Andrew (Princeton, NJ); Sibilia, Marc J. (Princeton, NJ); Miller, Jeffrey A. (Hopewell, NJ); Tonon, Thomas (Princeton, NJ)

    2007-09-18

    A mass and heat exchanger includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat exchange fluid therethrough, wherein heat transfer occurs between the liquid and the heat exchange fluid.

  6. Passive solar space heating

    SciTech Connect (OSTI)

    Balcomb, J.D.

    1980-01-01

    An overview of passive solar space heating is presented indicating trends in design, new developments, performance measures, analytical design aids, and monitored building results.

  7. HEATS: Thermal Energy Storage

    SciTech Connect (OSTI)

    2012-01-01

    HEATS Project: The 15 projects that make up ARPA-E’s HEATS program, short for “High Energy Advanced Thermal Storage,” seek to develop revolutionary, cost-effective ways to store thermal energy. HEATS focuses on 3 specific areas: 1) developing high-temperature solar thermal energy storage capable of cost-effectively delivering electricity around the clock and thermal energy storage for nuclear power plants capable of cost-effectively meeting peak demand, 2) creating synthetic fuel efficiently from sunlight by converting sunlight into heat, and 3) using thermal energy storage to improve the driving range of electric vehicles (EVs) and also enable thermal management of internal combustion engine vehicles.

  8. Multimegawatt gyrotrons for plasma heating

    SciTech Connect (OSTI)

    Advani, R.; Denison, D.; Kreischer, K.E.; Shapiro, M.A.; Temkin, R.J.

    1999-07-01

    The gyrotron is under development as a high power source for plasma heating at electron cyclotron resonance. For heating large scale plasmas, such as the DIII-D machine at General Atomics, it is advantageous to have high unit power heating sources to reduce the cost and complexity of the system. The authors will present preliminary designs of 1.5 and 2 MW gyrotrons at a frequency of 110 GHz. The gyrotron designs are based on previous successful results at the 1 MW level at frequencies from 110 to 170 GHz. The baseline design is for a TE{sub 28.8} mode cavity with an electron beam of 80 to 110 kV and a current of up to 80A. The expected efficiency exceeds 30% but it should increase to over 50% with a depressed collector. The output beam will be a Gaussian TEM{sub 00} mode in free space. The gyrotron will be investigated experimentally in short pulse operation (approximately 3 microseconds) at MIT and, if successful, will be developed in a 10s pulsed or CW version by industry. There are two competing approaches for the design of multimegawatt gyrotrons: conventional, cylindrical cavity gyrotrons and coaxial cavity gyrotrons. The conventional cavity approach is being considered as an extension of present day gyrotron research at 110 GHz. The coaxial cavity gyrotron is under investigation at MIT with the goal of output powers of 3 MW at 140 GHz. Recent experimental results from the coaxial cavity gyrotron at power levels in excess of 1 MW will be presented.

  9. Second derivatives for approximate spin projection methods

    SciTech Connect (OSTI)

    Thompson, Lee M.; Hratchian, Hrant P.

    2015-02-07

    The use of broken-symmetry electronic structure methods is required in order to obtain correct behavior of electronically strained open-shell systems, such as transition states, biradicals, and transition metals. This approach often has issues with spin contamination, which can lead to significant errors in predicted energies, geometries, and properties. Approximate projection schemes are able to correct for spin contamination and can often yield improved results. To fully make use of these methods and to carry out exploration of the potential energy surface, it is desirable to develop an efficient second energy derivative theory. In this paper, we formulate the analytical second derivatives for the Yamaguchi approximate projection scheme, building on recent work that has yielded an efficient implementation of the analytical first derivatives.

  10. Pulse design without rotating wave approximation

    E-Print Network [OSTI]

    S. Ibáñez; Yi-Chao Li; Xi Chen; J. G. Muga

    2015-10-21

    We design realizable time-dependent semiclassical pulses to invert the population of a two-level system faster than adiabatically when the rotating-wave approximation cannot be applied. Different approaches, based on the counterdiabatic method or on invariants, may lead to singularities in the pulse functions. Ways to avoid or cancel the singularities are put forward when the pulse spans few oscillations. For many oscillations an alternative numerical minimization method is proposed and demonstrated.

  11. Approximate convex decomposition and its applications 

    E-Print Network [OSTI]

    Lien, Jyh-Ming

    2009-05-15

    Approved by: Chair of Committee, Nancy M. Amato Committee Members, Ergun Akleman Ricardo Gutierrez-Osuna Donald H. House John C. Keyser Head of Department, Valerie E. Taylor December 2006 Major Subject: Computer Science iii ABSTRACT Approximate Convex...-Yen Li, for teaching me about research. I would like to thank my committee members, John Keyser, Donald House, Ergun Akleman, and Ricardo Gutierrez-Osuna, who supported me through this challenging journey. I would like to thank everyone in the Algorithms...

  12. Semiclassical approximation in Batalin-Vilkovisky formalism

    E-Print Network [OSTI]

    Albert Schwarz

    1992-10-23

    The geometry of supermanifolds provided with $Q$-structure (i.e. with odd vector field $Q$ satisfying $\\{ Q,Q\\} =0$), $P$-structure (odd symplectic structure ) and $S$-structure (volume element) or with various combinations of these structures is studied. The results are applied to the analysis of Batalin-Vilkovisky approach to the quantization of gauge theories. In particular the semiclassical approximation in this approach is expressed in terms of Reidemeister torsion.

  13. WKB Approximation to the Power Wall

    E-Print Network [OSTI]

    F. D. Mera; S. A. Fulling; J. D. Bouas; K. Thapa

    2013-03-28

    We present a semiclassical analysis of the quantum propagator of a particle confined on one side by a steeply, monotonically rising potential. The models studied in detail have potentials proportional to $x^{\\alpha}$ for $x>0$; the limit $\\alpha\\to\\infty$ would reproduce a perfectly reflecting boundary, but at present we concentrate on the cases $\\alpha =1$ and 2, for which exact solutions in terms of well known functions are available for comparison. We classify the classical paths in this system by their qualitative nature and calculate the contributions of the various classes to the leading-order semiclassical approximation: For each classical path we find the action $S$, the amplitude function $A$ and the Laplacian of $A$. (The Laplacian is of interest because it gives an estimate of the error in the approximation and is needed for computing higher-order approximations.) The resulting semiclassical propagator can be used to rewrite the exact problem as a Volterra integral equation, whose formal solution by iteration (Neumann series) is a semiclassical, not perturbative, expansion. We thereby test, in the context of a concrete problem, the validity of the two technical hypotheses in a previous proof of the convergence of such a Neumann series in the more abstract setting of an arbitrary smooth potential. Not surprisingly, we find that the hypotheses are violated when caustics develop in the classical dynamics; this opens up the interesting future project of extending the methods to momentum space.

  14. Nonlinear adaptive control using radial basis function approximants 

    E-Print Network [OSTI]

    Petersen, Jerry Lee

    1993-01-01

    The purpose of this research is to present an adaptive control strategy using the radial basis function approximation method. Surface approximation methods using radial basis function approximants will first be discussed. ...

  15. High Efficiency R-744 Commercial Heat Pump Water Heaters

    SciTech Connect (OSTI)

    Elbel, Dr. Stefan W.; Petersen, Michael

    2013-04-25

    The project investigated the development and improvement process of a R744 (CO2) commercial heat pump water heater (HPWH) package of approximately 35 kW. The improvement process covered all main components of the system. More specific the heat exchangers (Internal heat exchanger, Evaporator, Gas cooler) as well as the expansion device and the compressor were investigated. In addition, a comparison to a commercially available baseline R134a unit of the same capacity and footprint was made in order to compare performance as well as package size reduction potential.

  16. Collective Modes in a Superfluid Neutron Gas within the Quasiparticle Random-Phase Approximation

    E-Print Network [OSTI]

    Noël Martin; Michael Urban

    2015-01-05

    We study collective excitations in a superfluid neutron gas at zero temperature within the quasiparticle random phase approximation. The particle-hole residual interaction is obtained from a Skyrme functional, while a separable interaction is used in the pairing channel which gives a realistic density dependence of the pairing gap. In accordance with the Goldstone theorem, we find an ungapped collective mode (analogous to the Bogoliubov-Anderson mode). At low momentum, its dispersion relation is approximately linear and its slope coincides with the hydrodynamic speed of sound calculated with the Skyrme equation of state. The response functions are compared with those obtained within the Landau approximation. We also compute the contribution of the collective mode to the specific heat of the neutron gas, which is relevant for the thermodynamic properties of the inner crust of neutron stars.

  17. Inferring surface heat flux distributions guided by a global seismic model: particular application to Antarctica

    E-Print Network [OSTI]

    Shapiro, Nikolai

    , the procedure generates a histogram of heat-flow values determined from existing measurements obtained from are strongly non-Gaussian, but are well approximated by the log-logistic distribution which is completely

  18. A Better Steam Engine: Designing a Distributed Concentrating Solar Combined Heat and Power System

    E-Print Network [OSTI]

    Norwood, Zachary Mills

    2011-01-01

    2009, May). Solar heat worldwide: Markets and contributionis a large proven market for solar energy. With widespreadSolar Rankine thermodynamics matches California demand To get a first approximation of the market

  19. Heat pipes and use of heat pipes in furnace exhaust

    DOE Patents [OSTI]

    Polcyn, Adam D. (Pittsburgh, PA)

    2010-12-28

    An array of a plurality of heat pipe are mounted in spaced relationship to one another with the hot end of the heat pipes in a heated environment, e.g. the exhaust flue of a furnace, and the cold end outside the furnace. Heat conversion equipment is connected to the cold end of the heat pipes.

  20. First university owned district heating system using biomass heat

    E-Print Network [OSTI]

    Northern British Columbia, University of

    Highlights · First university owned district heating system using biomass heat · Capacity: 15 MMBtu Main Campus District Heating Performance · Avoided: 3500 tonnes of CO2 · Particulate: less than 10 mg District Heating Goals To displace 85% of natural gas used for core campus heating. Fuel Bunker Sawmill

  1. 4.A. HEAT FLOW 119 4.A. Heat flow

    E-Print Network [OSTI]

    Hunter, John K.

    denote the temperature, g : R the rate per unit volume at which heat sources create energy inside the body, and q : Rn the heat flux. That is, the rate per unit area at which heat energy diffuses across of energy implies that for any smooth open set the heat flux out of is equal to the rate at which heat

  2. Proceedings of Heat Transfer 2003: ASME Summer Heat Transfer Conference

    E-Print Network [OSTI]

    Kandlikar, Satish

    Proceedings of Heat Transfer 2003: ASME Summer Heat Transfer Conference Las Vegas, Nevada, USA July 21-23, 2003 HT2003-47449 HEAT TRANSFER FROM A MOVING AND EVAPORATING MENISCUS ON A HEATED SURFACE meniscus with complete evaporation of water without any meniscus break-up. The experimental heat transfer

  3. Heat Integrate Heat Engines in Process Plants 

    E-Print Network [OSTI]

    Hindmarsh, E.; Boland, D.; Townsend, D. W.

    1986-01-01

    -06-75 Proceedings from the Eighth Annual Industrial Energy Technology Conference, Houston, TX, June 17-19, 1986 I I APPROPRIATE/INAPPROPRIATE INTEGRATION OF HEiT PUMPS, engine transfers h'eat across the' process; pinch.'" . . :i".p., J The insights...

  4. Microchannel heat sink assembly

    DOE Patents [OSTI]

    Bonde, W.L.; Contolini, R.J.

    1992-03-24

    The present invention provides a microchannel heat sink with a thermal range from cryogenic temperatures to several hundred degrees centigrade. The heat sink can be used with a variety of fluids, such as cryogenic or corrosive fluids, and can be operated at a high pressure. The heat sink comprises a microchannel layer preferably formed of silicon, and a manifold layer preferably formed of glass. The manifold layer comprises an inlet groove and outlet groove which define an inlet manifold and an outlet manifold. The inlet manifold delivers coolant to the inlet section of the microchannels, and the outlet manifold receives coolant from the outlet section of the microchannels. In one embodiment, the manifold layer comprises an inlet hole extending through the manifold layer to the inlet manifold, and an outlet hole extending through the manifold layer to the outlet manifold. Coolant is supplied to the heat sink through a conduit assembly connected to the heat sink. A resilient seal, such as a gasket or an O-ring, is disposed between the conduit and the hole in the heat sink in order to provide a watertight seal. In other embodiments, the conduit assembly may comprise a metal tube which is connected to the heat sink by a soft solder. In still other embodiments, the heat sink may comprise inlet and outlet nipples. The present invention has application in supercomputers, integrated circuits and other electronic devices, and is suitable for cooling materials to superconducting temperatures. 13 figs.

  5. Microchannel heat sink assembly

    DOE Patents [OSTI]

    Bonde, Wayne L. (Livermore, CA); Contolini, Robert J. (Pleasanton, CA)

    1992-01-01

    The present invention provides a microchannel heat sink with a thermal range from cryogenic temperatures to several hundred degrees centigrade. The heat sink can be used with a variety of fluids, such as cryogenic or corrosive fluids, and can be operated at a high pressure. The heat sink comprises a microchannel layer preferably formed of silicon, and a manifold layer preferably formed of glass. The manifold layer comprises an inlet groove and outlet groove which define an inlet manifold and an outlet manifold. The inlet manifold delivers coolant to the inlet section of the microchannels, and the outlet manifold receives coolant from the outlet section of the microchannels. In one embodiment, the manifold layer comprises an inlet hole extending through the manifold layer to the inlet manifold, and an outlet hole extending through the manifold layer to the outlet manifold. Coolant is supplied to the heat sink through a conduit assembly connected to the heat sink. A resilient seal, such as a gasket or an O-ring, is disposed between the conduit and the hole in the heat sink in order to provide a watetight seal. In other embodiments, the conduit assembly may comprise a metal tube which is connected to the heat sink by a soft solder. In still other embodiments, the heat sink may comprise inlet and outlet nipples. The present invention has application in supercomputers, integrated circuits and other electronic devices, and is suitable for cooling materials to superconducting temperatures.

  6. Chemical heat pump

    DOE Patents [OSTI]

    Greiner, Leonard (2853-A Hickory Pl., Costa Mesa, CA 92626)

    1984-01-01

    A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate intallation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

  7. Chemical heat pump

    DOE Patents [OSTI]

    Greiner, Leonard (2853-A Hickory Pl., Costa Mesa, CA 92626)

    1984-01-01

    A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

  8. Chemical heat pump

    DOE Patents [OSTI]

    Greiner, Leonard (2853-A Hickory Pl., Costa Mesa, CA 92626)

    1984-01-01

    A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to faciliate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

  9. Chemical heat pump

    DOE Patents [OSTI]

    Greiner, Leonard (2853-A Hickory Pl., Costa Mesa, CA 92626)

    1981-01-01

    A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

  10. Knudsen heat capacity

    SciTech Connect (OSTI)

    Babac, Gulru; Reese, Jason M.

    2014-05-15

    We present a “Knudsen heat capacity” as a more appropriate and useful fluid property in micro/nanoscale gas systems than the constant pressure heat capacity. At these scales, different fluid processes come to the fore that are not normally observed at the macroscale. For thermodynamic analyses that include these Knudsen processes, using the Knudsen heat capacity can be more effective and physical. We calculate this heat capacity theoretically for non-ideal monatomic and diatomic gases, in particular, helium, nitrogen, and hydrogen. The quantum modification for para and ortho hydrogen is also considered. We numerically model the Knudsen heat capacity using molecular dynamics simulations for the considered gases, and compare these results with the theoretical ones.

  11. Improved solar heating systems

    DOE Patents [OSTI]

    Schreyer, J.M.; Dorsey, G.F.

    1980-05-16

    An improved solar heating system is described in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75 to 180/sup 0/F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing ad releasing heat for distribution.

  12. Solar heating system

    DOE Patents [OSTI]

    Schreyer, James M. (Oak Ridge, TN); Dorsey, George F. (Concord, TN)

    1982-01-01

    An improved solar heating system in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75.degree. to 180.degree. F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing and releasing heat for distribution.

  13. First principles computation of thermochemical properties beyond the harmonic approximation. I. Method and application to the water

    E-Print Network [OSTI]

    Martin, Jan M.L.

    First principles computation of thermochemical properties beyond the harmonic approximation. I of thermochemical data for molecules and reactions hardly needs to be stressed. Compilations like the JANAF tables' list free energy functions, entropies, enthalpies, and molar heats as a function of temperature from

  14. Heat Exchangers for Solar Water Heating Systems | Department...

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

    from iStockphoto.com Image of a heat exchanger. | Photo from iStockphoto.com Solar water heating systems use heat exchangers to transfer solar energy absorbed in solar...

  15. Heat Transfer Fluids for Solar Water Heating Systems | Department...

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

    commonly used as the heat transfer fluid in refrigerators, air conditioners, and heat pumps. They generally have a low boiling point and a high heat capacity. This enables a...

  16. Heat Exchangers for Solar Water Heating Systems | Department...

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

    air used to heat water or a space. Heat exchangers can be made of steel, copper, bronze, stainless steel, aluminum, or cast iron. Solar heating systems usually use copper, because...

  17. Sensitivity approximation for robust stability and tracking 

    E-Print Network [OSTI]

    McLean, Chris Steven

    1984-01-01

    ) Norman W. Na gle (Member) Don R. Halverson (Member) William B. Jones (Head of Department) May 1984 1n Abstract Sensitivity Approximation for Robust Stability and Tracking. (May 1984) Chris Steven McLean, B. S, , Louisiana Tech University... indispensable to the completion of this thesis. I would like to thank Dr. S. P. Bhattacharyya for introducing me to the wonders of automatic control. I also would like to thank Dr. D. R. Halverson and Dr. N. W. Naugle for serving on my committee, Dr. John...

  18. Relativistic Random Phase Approximation At Finite Temperature

    SciTech Connect (OSTI)

    Niu, Y. F.; Paar, N.; Vretenar, D.; Meng, J.

    2009-08-26

    The fully self-consistent finite temperature relativistic random phase approximation (FTRRPA) has been established in the single-nucleon basis of the temperature dependent Dirac-Hartree model (FTDH) based on effective Lagrangian with density dependent meson-nucleon couplings. Illustrative calculations in the FTRRPA framework show the evolution of multipole responses of {sup 132}Sn with temperature. With increased temperature, in both monopole and dipole strength distributions additional transitions appear in the low energy region due to the new opened particle-particle and hole-hole transition channels.

  19. Micro heat barrier

    DOE Patents [OSTI]

    Marshall, Albert C.; Kravitz, Stanley H.; Tigges, Chris P.; Vawter, Gregory A.

    2003-08-12

    A highly effective, micron-scale micro heat barrier structure and process for manufacturing a micro heat barrier based on semiconductor and/or MEMS fabrication techniques. The micro heat barrier has an array of non-metallic, freestanding microsupports with a height less than 100 microns, attached to a substrate. An infrared reflective membrane (e.g., 1 micron gold) can be supported by the array of microsupports to provide radiation shielding. The micro heat barrier can be evacuated to eliminate gas phase heat conduction and convection. Semi-isotropic, reactive ion plasma etching can be used to create a microspike having a cusp-like shape with a sharp, pointed tip (<0.1 micron), to minimize the tip's contact area. A heat source can be placed directly on the microspikes. The micro heat barrier can have an apparent thermal conductivity in the range of 10.sup.-6 to 10.sup.-7 W/m-K. Multiple layers of reflective membranes can be used to increase thermal resistance.

  20. Integrating preconcentrator heat controller

    DOE Patents [OSTI]

    Bouchier, Francis A. (Albuquerque, NM); Arakaki, Lester H. (Edgewood, NM); Varley, Eric S. (Albuquerque, NM)

    2007-10-16

    A method and apparatus for controlling the electric resistance heating of a metallic chemical preconcentrator screen, for example, used in portable trace explosives detectors. The length of the heating time-period is automatically adjusted to compensate for any changes in the voltage driving the heating current across the screen, for example, due to gradual discharge or aging of a battery. The total deposited energy in the screen is proportional to the integral over time of the square of the voltage drop across the screen. Since the net temperature rise, .DELTA.T.sub.s, of the screen, from beginning to end of the heating pulse, is proportional to the total amount of heat energy deposited in the screen during the heating pulse, then this integral can be calculated in real-time and used to terminate the heating current when a pre-set target value has been reached; thereby providing a consistent and reliable screen temperature rise, .DELTA.T.sub.s, from pulse-to-pulse.

  1. Convergence analysis of the thermal discrete dipole approximation

    E-Print Network [OSTI]

    Edalatpour, Sheila; Trueax, Tyler; Backman, Roger; Francoeur, Mathieu

    2015-01-01

    The thermal discrete dipole approximation (T-DDA) is a numerical approach for modeling near-field radiative heat transfer in complex three-dimensional geometries. In this work, the convergence of the T-DDA is investigated using the exact solution for two spheres separated by a vacuum gap. The error associated with the T-DDA is reported for various size parameters, refractive indices and vacuum gap sizes. The results reveal that for a fixed number of sub-volumes, the accuracy of the T-DDA degrades as the refractive index and the sphere diameter to gap ratio increase. A converging trend is observed as the number of sub-volumes increases. The large computational requirements associated with increasing the number of sub-volumes, and the shape error induced by large sphere diameter to gap ratios, are mitigated by using a non-uniform discretization scheme. Non-uniform discretization is shown to significantly accelerate the convergence of the T-DDA, and is thus recommended for near-field thermal radiation simulation...

  2. PIA - Northeast Home Heating Oil Reserve System (Heating Oil...

    Energy Savers [EERE]

    Home Heating Oil Reserve System (Heating Oil) More Documents & Publications PIA - WEB Physical Security Major Application PIA - GovTrip (DOE data) PIA - WEB Unclassified...

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

    Open Energy Info (EERE)

    Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas- Features And Examples Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article:...

  4. Condensing Heating and Water Heating Equipment Workshop Location...

    Energy Savers [EERE]

    Condensing Heating and Water Heating Equipment Workshop Location: Washington Gas Light Appliance Training Facility 6801 Industrial Road Springfield, VA Date: October 9, 2014 Time:...

  5. TRANSPARENT HEAT MIRRORS FOR PASSIVE SOLAR HEATING APPLICATIONS

    E-Print Network [OSTI]

    Selkowitz, S.

    2011-01-01

    advantage of light transmission through heat mirrors may notimportant but heat gain may not be, the transmission windowheat mirror coating alone (without substrate losses) is a solar transmission

  6. Low-Cost Gas Heat Pump for Building Space Heating

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

    Low-Cost Gas Heat Pump for Building Space Heating 2015 Building Technologies Office Peer Review Michael Garrabrant mgarrabrant@stonemtntechnologies.com Stone Mountain Technologies,...

  7. Low-Cost Gas Heat Pump for Building Space Heating

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

    Low-Cost Gas Heat Pump for Building Space Heating 2014 Building Technologies Office Peer Review Michael Garrabrant mgarrabrant@stonemtntechnologies.com Stone Mountain Technologies,...

  8. Impact of a retrofitted heat-recovery unit on an existing residential heat pump and water heater. Final report

    SciTech Connect (OSTI)

    Tu, K.M.; Fischler, S.

    1980-01-01

    Two heat-recovery units were retrofitted, one at a time, with one heat pump and one storage-type water heater to produce two integrated heat pump - heat recovery unit - water heater systems. Each system was operated with appropriate measuring devices to determine the effect(s) of using the retrofit heat recovery unit on the performance of the heat pump and water heater. The system was operated with the outdoor unit of the heat pump in an environmental chamber with outdoor temperatures of 75, 85, 95, and 20F. The indoor unit of the heat pump was in an environmental chamber whose indoor temperature was set at 80F when the outdoor temperature was 75, 85, 95F, and 70F when the outdoor temperature was set at 20F. The indoor relative humidity was maintained at approximately 50%. The heat recovery unit and water heater were in an environmental chamber set at the basement temperature of 65F with 50% relative humidity.

  9. The Background Field Approximation in (quantum) cosmology

    E-Print Network [OSTI]

    R. Parentani

    1998-03-12

    We analyze the Hamilton-Jacobi action of gravity and matter in the limit where gravity is treated at the background field approximation. The motivation is to clarify when and how the solutions of the Wheeler-DeWitt equation lead to the Schr\\"odinger equation in a given background. To this end, we determine when and how the total action, solution of the constraint equations of General Relativity, leads to the HJ action for matter in a given background. This is achieved by comparing two neighboring solutions differing slightly in their matter energy content. To first order in the change of the 3-geometries, the change of the gravitational action equals the integral of the matter energy evaluated in the background geometry. Higher order terms are governed by the ``susceptibility'' of the geometry. These classical properties also apply to quantum cosmology since the conditions which legitimize the use of WKB gravitational waves are concomitant with those governing the validity of the background field approximation.

  10. The local potential approximation in quantum gravity

    E-Print Network [OSTI]

    Dario Benedetti; Francesco Caravelli

    2012-10-09

    Within the context of the functional renormalization group flow of gravity, we suggest that a generic f(R) ansatz (i.e. not truncated to any specific form, polynomial or not) for the effective action plays a role analogous to the local potential approximation (LPA) in scalar field theory. In the same spirit of the LPA, we derive and study an ordinary differential equation for f(R) to be satisfied by a fixed point of the renormalization group flow. As a first step in trying to assess the existence of global solutions (i.e. true fixed point) for such equation, we investigate here the properties of its solutions by a comparison of various series expansions and numerical integrations. In particular, we study the analyticity conditions required because of the presence of fixed singularities in the equation, and we develop an expansion of the solutions for large R up to order N=29. Studying the convergence of the fixed points of the truncated solutions with respect to N, we find a characteristic pattern for the location of the fixed points in the complex plane, with one point stemming out for its stability. Finally, we establish that if a non-Gaussian fixed point exists within the full f(R) approximation, it corresponds to an R^2 theory.

  11. Molecular heat pump

    E-Print Network [OSTI]

    Dvira Segal; Abraham Nitzan

    2005-10-11

    We propose a novel molecular device that pumps heat against a thermal gradient. The system consists of a molecular element connecting two thermal reservoirs that are characterized by different spectral properties. The pumping action is achieved by applying an external force that periodically modulates molecular levels. This modulation affects periodic oscillations of the internal temperature of the molecule and the strength of its coupling to each reservoir resulting in a net heat flow in the desired direction. The heat flow is examined in the slow and fast modulation limits and for different modulation waveforms, thus making it possible to optimize the device performance.

  12. Heat treatment furnace

    DOE Patents [OSTI]

    Seals, Roland D; Parrott, Jeffrey G; DeMint, Paul D; Finney, Kevin R; Blue, Charles T

    2014-10-21

    A furnace heats through both infrared radiation and convective air utilizing an infrared/purge gas design that enables improved temperature control to enable more uniform treatment of workpieces. The furnace utilizes lamps, the electrical end connections of which are located in an enclosure outside the furnace chamber, with the lamps extending into the furnace chamber through openings in the wall of the chamber. The enclosure is purged with gas, which gas flows from the enclosure into the furnace chamber via the openings in the wall of the chamber so that the gas flows above and around the lamps and is heated to form a convective mechanism in heating parts.

  13. Stirling engine heating system

    SciTech Connect (OSTI)

    Johansson, L.N.; Houtman, W.H.; Percival, W.H.

    1988-06-28

    A hot gas engine is described wherein a working gas flows back and forth in a closed path between a relatively cooler compression cylinder side of the engine and a relatively hotter expansion cylinder side of the engine and the path contains means including a heat source and a heat sink acting upon the gas in cooperation with the compression and expansion cylinders to cause the gas to execute a thermodynamic cycle wherein useful mechanical output power is developed by the engine, the improvement in the heat source which comprises a plurality of individual tubes each forming a portion of the closed path for the working gas.

  14. Specifying Waste Heat Boilers 

    E-Print Network [OSTI]

    Ganapathy, V.

    1992-01-01

    HEAT BOILERS V.Ganapathy.ABCO Industries Abilene,Texas ABSTRACT Waste heat boilers or Heat Recovery Steam 'Generators(HRSGs) as they are often called are used to recover energy from waste gas streams in chemical plants, refineries... stream_source_info ESL-IE-92-04-42.pdf.txt stream_content_type text/plain stream_size 11937 Content-Encoding ISO-8859-1 stream_name ESL-IE-92-04-42.pdf.txt Content-Type text/plain; charset=ISO-8859-1 SPECIFYING WASTE...

  15. Heating & Cooling | Department of Energy

    Energy Savers [EERE]

    Energy Saver Heating & Cooling Heating & Cooling Heating and cooling account for about 48% of the energy use in a typical U.S. home, making it the largest energy expense for...

  16. Energy 101: Geothermal Heat Pumps

    Broader source: Energy.gov [DOE]

    An energy-efficient heating and cooling alternative, the geothermal heat pump system moves heat from the ground to a building (or from a building to the ground) through a series of flexible pipe ...

  17. Complex Compound Chemical Heat Pumps 

    E-Print Network [OSTI]

    Rockenfeller, U.; Langeliers, J.; Horn, G.

    1987-01-01

    Complex-compound solid-vapor fluid pairs can be used in heat of reaction heat pumps for temperature amplifier (TA) as well as heat amplifier (HA) cycle configurations. This report describes the conceptual hardware design for complex compound...

  18. Water Heating | Department of Energy

    Energy Savers [EERE]

    Water Heating Water Heating September 2, 2015 - 11:07am Addthis Low-flow fixtures will help you reduce your hot water use and save money on your water heating bills. | Photo...

  19. Recycling Authorizations: Toward Secondary and Approximate Authorizations Model

    E-Print Network [OSTI]

    of matching best suitable approximate authorizations. 1 Introduction Although, every authorization decision

  20. Bethe free energy, Kikuchi approximations and belief propagation

    E-Print Network [OSTI]

    Bethe free energy, Kikuchi approximations and belief propagation algorithms Jonathan S. Yedidia to a stationary point of an approximate free energy, known as the Bethe free energy in statis- tical physics- curate free energy approximations, of which Bethe's approximation is the simplest. Exploiting

  1. Fabrication and heating rate study of microscopic surface electrode ion traps

    E-Print Network [OSTI]

    N. Daniilidis; S. Narayanan; S. A. Möller; R. Clark; T. E. Lee; P. J. Leek; A. Wallraff; St. Schulz; F. Schmidt-Kaler; H. Häffner

    2010-09-15

    We report heating rate measurements in a microfabricated gold-on-sapphire surface electrode ion trap with trapping height of approximately 240 micron. Using the Doppler recooling method, we characterize the trap heating rates over an extended region of the trap. The noise spectral density of the trap falls in the range of noise spectra reported in ion traps at room temperature. We find that during the first months of operation the heating rates increase by approximately one order of magnitude. The increase in heating rates is largest in the ion loading region of the trap, providing a strong hint that surface contamination plays a major role for excessive heating rates. We discuss data found in the literature and possible relation of anomalous heating to sources of noise and dissipation in other systems, namely impurity atoms adsorbed on metal surfaces and amorphous dielectrics.

  2. On the controllability of the heat equation with nonlinear boundary Fourier conditions

    E-Print Network [OSTI]

    González Burgos, Manuel

    On the controllability of the heat equation with nonlinear boundary Fourier conditions A. Doubova (among other things) H¨older estimates for the control and the state. Key words: Controllability, heat, 41080 Sevilla, Spain. Abstract In this paper we analyze the approximate and null controllability

  3. Numerical exact controllability of the 1D heat equation: dual algorithms

    E-Print Network [OSTI]

    Sart, Remi

    Numerical exact controllability of the 1D heat equation: dual algorithms Enrique Fern, which is closely related to the regularization effect of the heat equation. There, the controllability´andez-Cara and Arnaud M¨unch Abstract This work addresses the numerical approximation of distributed null controls (with

  4. NUMERICAL NULL CONTROLLABILITY OF THE HEAT EQUATION THROUGH A VARIATIONAL APPROACH

    E-Print Network [OSTI]

    Sart, Remi

    NUMERICAL NULL CONTROLLABILITY OF THE HEAT EQUATION THROUGH A VARIATIONAL APPROACH ARNAUD M for the heat equation. The goal is to compute a control that drives (an approximation of) the solution from¨UNCH AND PABLO PEDREGAL Abstract. This work is concerned with the numerical computation of null controls

  5. Photovoltaic roof heat flux

    E-Print Network [OSTI]

    Samady, Mezhgan Frishta

    2011-01-01

    e l Atmosphere ceiling, back panel roof, exposed roof insideSAN DIEGO Photovoltaic Roof Heat Flux A Thesis submitted i no n Convection Exposed Roof Temperature Seasonal Temperature

  6. Passive solar heating analysis

    SciTech Connect (OSTI)

    Balcomb, J.D.; Jones, R.W.; Mc Farland, R.D.; Wray, W.O.

    1984-01-01

    This book discusses about the design of solar heating systems. The terms and symbols are clearly defined. Step-by-step procedures are indicated. Worked examples are given with tables, graphs, appendixes.

  7. Heating Plant Emergency Instructions

    E-Print Network [OSTI]

    de Leon, Alex R.

    Heating Plant Emergency Instructions In the event of an EMERGENCY dial 403-220-5333 for Campus room, closet or hallway (ground floor, if possible) Stay away from outside walls, windows and doors

  8. Greywater heat exchanger

    SciTech Connect (OSTI)

    Holmberg, D.

    1983-11-21

    A kilowatt meter and water meter were installed to monitor pregreywater usage. The design considerations, the heat exchanger construction and installation, and the monitoring of usage levels are described.

  9. Asymptotic solution for heat convection-radiation equation

    SciTech Connect (OSTI)

    Mabood, Fazle; Ismail, Ahmad Izani Md [School of Mathematical Sciences, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Khan, Waqar A. [Department of Engineering Sciences, National University of Sciences and Technology, PN Engineering College, Karachi, 75350 (Pakistan)

    2014-07-10

    In this paper, we employ a new approximate analytical method called the optimal homotopy asymptotic method (OHAM) to solve steady state heat transfer problem in slabs. The heat transfer problem is modeled using nonlinear two-point boundary value problem. Using OHAM, we obtained the approximate analytical solution for dimensionless temperature with different values of a parameter ?. Further, the OHAM results for dimensionless temperature have been presented graphically and in tabular form. Comparison has been provided with existing results from the use of homotopy perturbation method, perturbation method and numerical method. For numerical results, we used Runge-Kutta Fehlberg fourth-fifth order method. It was found that OHAM produces better approximate analytical solutions than those which are obtained by homotopy perturbation and perturbation methods, in the sense of closer agreement with results obtained from the use of Runge-Kutta Fehlberg fourth-fifth order method.

  10. Heat Pump Strategies and Payoffs 

    E-Print Network [OSTI]

    Gilbert, J. S.

    1982-01-01

    (Evaporator) Heat Source Heat Pump Turbine Compressor Compressed Vapor Pump IZl:G1 Type IV - Rankine Cycle (Waste Heat Driven) Heat Sink (Condenser) Fig. 3 Basic Heat Pump Categories 324 ESL-IE-82-04-66 Proceedings from the Fourth Industrial... payback. 500 450 400 Leas Than G:" ~ 2! 350 2-Vear Payback .a e 300 !. E ~ 250 Simple Waste Heat Boller 200 100 1.-........_-'-_.1.---1"---.1._..&0.._1.---'-_'-__ o 10 20 30 40 50 60 70 80 Heat Removed (%) 82291 Fig. 4 Heat...

  11. Water Heating | Department of Energy

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

    Public Services Homes Water Heating Water Heating Infographic: Water Heaters 101 Infographic: Water Heaters 101 Everything you need to know about saving money on water...

  12. NGNP Process Heat Utilization: Liquid Metal Phase Change Heat Exchanger

    SciTech Connect (OSTI)

    Piyush Sabharwall; Mike Patterson; Vivek Utgikar; Fred Gunnerson

    2008-09-01

    One key long-standing issue that must be overcome to fully realize the successful growth of nuclear power is to determine other benefits of nuclear energy apart from meeting the electricity demands. The Next Generation Nuclear Plant (NGNP) will most likely be producing electricity and heat for the production of hydrogen and/or oil retrieval from oil sands and oil shale to help in our national pursuit of energy independence. For nuclear process heat to be utilized, intermediate heat exchange is required to transfer heat from the NGNP to the hydrogen plant or oil recovery field in the most efficient way possible. Development of nuclear reactor - process heat technology has intensified the interest in liquid metals as heat transfer media because of their ideal transport properties. Liquid metal heat exchangers are not new in practical applications. An important rational for considering liquid metals is the potential convective heat transfer is among the highest known. Thus explains the interest in liquid metals as coolant for intermediate heat exchange from NGNP. For process heat it is desired that, intermediate heat exchangers (IHX) transfer heat from the NGNP in the most efficient way possible. The production of electric power at higher efficiency via the Brayton Cycle, and hydrogen production, requires both heat at higher temperatures and high effectiveness compact heat exchangers to transfer heat to either the power or process cycle. Compact heat exchangers maximize the heat transfer surface area per volume of heat exchanger; this has the benefit of reducing heat exchanger size and heat losses. High temperature IHX design requirements are governed in part by the allowable temperature drop between the outlet and inlet of the NGNP. In order to improve the characteristics of heat transfer, liquid metal phase change heat exchangers may be more effective and efficient. This paper explores the overall heat transfer characteristics and pressure drop of the phase change heat exchanger with Na as the heat exchanger coolant. In order to design a very efficient and effective heat exchanger one must optimize the design such that we have a high heat transfer and a lower pressure drop, but there is always a trade-off between them. Based on NGNP operational parameters, a heat exchanger analysis with the sodium phase change will be presented to show that the heat exchanger has the potential for highly effective heat transfer, within a small volume at reasonable cost.

  13. Heat exchange apparatus

    DOE Patents [OSTI]

    Degtiarenko, Pavel V.

    2003-08-12

    A heat exchange apparatus comprising a coolant conduit or heat sink having attached to its surface a first radial array of spaced-apart parallel plate fins or needles and a second radial array of spaced-apart parallel plate fins or needles thermally coupled to a body to be cooled and meshed with, but not contacting the first radial array of spaced-apart parallel plate fins or needles.

  14. Freezable heat pipe

    DOE Patents [OSTI]

    Ernst, Donald M. (Leola, PA); Sanzi, James L. (Lancaster, PA)

    1981-02-03

    A heat pipe whose fluid can be repeatedly frozen and thawed without damage to the casing. An additional part is added to a conventional heat pipe. This addition is a simple porous structure, such as a cylinder, self-supporting and free standing, which is dimensioned with its diameter not spanning the inside transverse dimension of the casing, and with its length surpassing the depth of maximum liquid.

  15. Integrated heat pump water heater

    SciTech Connect (OSTI)

    Robinson, G.P.; Blackshaw, A.L.

    1986-07-08

    An integrated heat pump water heater system is described for providing either heating or cooling of an interior space, and heating water in conjunction with either the heating or cooling cycle or independently, by means of a refrigerant flowing through the system. The system consists of: a compressor; a first heat exchanger means for providing heat to the interior space in the heating cycle and for removing heat during the cooling cycle by heat transfer with a refrigerant therein; a second heat exchanger means for transferring heat to or from a refrigerant therein by heat exchanger with an exterior medium; a third heat exchanger means for transferring heat from a refrigerant therein to water circulated therethrough; a first expansion device; a second expansion device; a third expansion device; refrigerant flow connection means connected between the compressor, the heat exchanger means, and the expansion devices which may be controllably connected in alternate configurations whereby. In a first configuration the refrigerant flow is sequentially from the compressor, through the third heat exchanger means, through the second heat exchanger means, through the first expansion device, through the first heat exchanger means, and back to the compressor. In a second configuration the refrigerant flow is sequentially from the compressor, through the third heat exchanger means, through the first heat exchanger means, through the second expansion device, through the second heat exchanger means, and back to the compressor. In a third configuration the refrigerant flow is sequentially from the compressor, through the third heat exchanger means, through the third expansion device, through the second heat exchanger means, and back to the compressor.

  16. Radial flow heat exchanger

    DOE Patents [OSTI]

    Valenzuela, Javier (Hanover, NH)

    2001-01-01

    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.

  17. Convective heat flow probe

    DOE Patents [OSTI]

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

    1984-01-09

    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.

  18. Intrinsically irreversible heat engine

    DOE Patents [OSTI]

    Wheatley, J.C.; Swift, G.W.; Migliori, A.

    1984-12-25

    A class of heat engines based on an intrinsically irreversible heat transfer process is disclosed. In a typical embodiment the engine comprises a compressible fluid that is cyclically compressed and expanded while at the same time being driven in reciprocal motion by a positive displacement drive means. A second thermodynamic medium is maintained in imperfect thermal contact with the fluid and bears a broken thermodynamic symmetry with respect to the fluid. The second thermodynamic medium is a structure adapted to have a low fluid flow impedance with respect to the compressible fluid, and which is further adapted to be in only moderate thermal contact with the fluid. In operation, thermal energy is pumped along the second medium due to a phase lag between the cyclical heating and cooling of the fluid and the resulting heat conduction between the fluid and the medium. In a preferred embodiment the engine comprises an acoustical drive and a housing containing a gas which is driven at a resonant frequency so as to be maintained in a standing wave. Operation of the engine at acoustic frequencies improves the power density and coefficient of performance. The second thermodynamic medium can be coupled to suitable heat exchangers to utilize the engine as a simple refrigeration device having no mechanical moving parts. Alternatively, the engine is reversible in function so as to be utilizable as a prime mover by coupling it to suitable sources and sinks of heat. 11 figs.

  19. Intrinsically irreversible heat engine

    DOE Patents [OSTI]

    Wheatley, J.C.; Swift, G.W.; Migliori, A.

    1984-01-01

    A class of heat engines based on an intrinsically irreversible heat transfer process is disclosed. In a typical embodiment the engine comprises a compressible fluid that is cyclically compressed and expanded while at the same time being driven in reciprocal motion by a positive displacement drive means. A second thermodynamic medium is maintained in imperfect thermal contact with the fluid and bears a broken thermodynamic symmetry with respect to the fluid. The second thermodynamic medium is a structure adapted to have a low fluid flow impedance with respect to the compressible fluid, and which is further adapted to be in only moderate thermal contact with the fluid. In operation, thermal energy is pumped along the second medium due to a phase lag between the cyclical heating and cooling of the fluid and the resulting heat conduction between the fluid and the medium. In a preferred embodiment the engine comprises an acoustical drive and a housing containing a gas which is driven at a resonant frequency so as to be maintained in a standing wave. Operation of the engine at acoustic frequencies improves the power density and coefficient of performance. The second thermodynamic medium can be coupled to suitable heat exchangers to utilize the engine as a simple refrigeration device having no mechanical moving parts. Alternatively, the engine is reversible in function so as to be utilizable as a prime mover by coupling it to suitable sources and sinks of heat.

  20. Intrinsically irreversible heat engine

    DOE Patents [OSTI]

    Wheatley, John C. (Los Alamos, NM); Swift, Gregory W. (Los Alamos, NM); Migliori, Albert (Santa Fe, NM)

    1984-01-01

    A class of heat engines based on an intrinsically irreversible heat transfer process is disclosed. In a typical embodiment the engine comprises a compressible fluid that is cyclically compressed and expanded while at the same time being driven in reciprocal motion by a positive displacement drive means. A second thermodynamic medium is maintained in imperfect thermal contact with the fluid and bears a broken thermodynamic symmetry with respect to the fluid. the second thermodynamic medium is a structure adapted to have a low fluid flow impedance with respect to the compressible fluid, and which is further adapted to be in only moderate thermal contact with the fluid. In operation, thermal energy is pumped along the second medium due to a phase lag between the cyclical heating and cooling of the fluid and the resulting heat conduction between the fluid and the medium. In a preferred embodiment the engine comprises an acoustical drive and a housing containing a gas which is driven at a resonant frequency so as to be maintained in a standing wave. Operation of the engine at acoustic frequencies improves the power density and coefficient of performance. The second thermodynamic medium can be coupled to suitable heat exchangers to utilize the engine as a simple refrigeration device having no mechanical moving parts. Alternatively, the engine is reversible in function so as to be utilizable as a prime mover by coupling it to suitable sources and sinks of heat.

  1. Approximate Stokes Drift Profiles in Deep Water

    E-Print Network [OSTI]

    Breivik, Øyvind; Bidlot, Jean-Raymond

    2014-01-01

    A deep-water approximation to the Stokes drift velocity profile is explored as an alternative to the monochromatic profile. The alternative profile investigated relies on the same two quantities required for the monochromatic profile, viz the Stokes transport and the surface Stokes drift velocity. Comparisons with parametric spectra and profiles under wave spectra from the ERA-Interim reanalysis and buoy observations reveal much better agreement than the monochromatic profile even for complex sea states. That the profile gives a closer match and a more correct shear has implications for ocean circulation models since the Coriolis-Stokes force depends on the magnitude and direction of the Stokes drift profile and Langmuir turbulence parameterizations depend sensitively on the shear of the profile. The alternative profile comes at no added numerical cost compared to the monochromatic profile.

  2. Pairing and specific heat in hot nuclei

    E-Print Network [OSTI]

    Danilo Gambacurta; Denis Lacroix; Nicu Sandulescu

    2013-07-15

    The thermodynamics of pairing phase-transition in nuclei is studied in the canonical ensemble and treating the pairing correlations in a finite-temperature variation after projection BCS approach (FT-VAP). Due to the restoration of particle number conservation, the pairing gap and the specific heat calculated in the FT-VAP approach vary smoothly with the temperature, indicating a gradual transition from the superfluid to the normal phase, as expected in finite systems. We have checked that the predictions of the FT-VAP approach are very accurate when compared to the results obtained by an exact diagonalization of the pairing Hamiltonian. The influence of pairing correlations on specific heat is analysed for the isotopes $^{161,162}$Dy and $^{171,172}$Yb. It is shown that the FT-VAP approach, applied with a level density provided by mean field calculations and supplemented, at high energies, by the level density of the back-shifted Fermi gas model, can approximate reasonably well the main properties of specific heat extracted from experimental data. However, the detailed shape of the calculated specific heat is rather sensitive to the assumption made for the mean field.

  3. Theory of Off Resonance Heat:ing J .C. SPROTI

    E-Print Network [OSTI]

    Sprott, Julien Clinton

    The heating rate for a cold, tenuous, unifonn plasma in a unifonn magnetic field can be written as (1) where E previously proved successful for calculating resonance heating rates. II. Upper off Resonance Heating, and the resulting heating rate is independent of the collision frequency v . It is often said that there can

  4. Solar air heating system for combined DHW and space heating

    E-Print Network [OSTI]

    Solar air heating system for combined DHW and space heating solar air collector PV-panel fannon-return valve DHW tank mantle cold waterhot water roof Solar Energy Centre Denmark Danish Technological Institute SEC-R-29 #12;Solar air heating system for combined DHW and space heating Søren Østergaard Jensen

  5. Heat exchanger device and method for heat removal or transfer

    DOE Patents [OSTI]

    Koplow, Jeffrey P. (San Ramon, CA)

    2012-07-24

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

  6. Heat exchanger device and method for heat removal or transfer

    DOE Patents [OSTI]

    Koplow, Jeffrey P.

    2015-12-08

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

  7. Heat exchanger device and method for heat removal or transfer

    DOE Patents [OSTI]

    Koplow, Jeffrey P

    2013-12-10

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

  8. Dynamic control of quantum geometric heat flux in a nonequilibrium spin-boson model

    E-Print Network [OSTI]

    Tian Chen; Xiang-Bin Wang; Jie Ren

    2013-04-24

    We study the quantum geometric heat flux in the nonequilibrium spin-boson model. By adopting the noninteracting-blip approximation that is able to accommodate the strong system-bath coupling, we show that there exists a nonzero geometric heat flux only when the two-level system is nondegenerate. Moreover, the pumping, no pumping, and dynamic control of geometric heat flux are discussed in detail, compared to the results with Redfield weak-coupling approximation. In particular, the geometric energy transfer induced by modulation of two system-bath couplings is identified, which is exclusive to quantum transport in the strong system-bath coupling regime.

  9. Toolbox Safety Talk Heat Stress

    E-Print Network [OSTI]

    Pawlowski, Wojtek

    Toolbox Safety Talk Heat Stress Environmental Health & Safety Facilities Safety & Health Section for inducing heat stress. When the body is unable to cool itself by sweating, several heat-induced illnesses Stress · Know signs/symptoms of heat-related illnesses; monitor yourself and coworkers. · Block out

  10. Guide to Geothermal Heat Pumps

    SciTech Connect (OSTI)

    None

    2011-02-01

    Geothermal heat pumps, also known as ground source heat pumps, geoexchange, water-source, earth-coupled, and earth energy heat pumps, take advantage of this resource and represent one of the most efficient and durable options on the market to heat and cool your home.

  11. Heat exchanger-accumulator

    DOE Patents [OSTI]

    Ecker, Amir L. (Dallas, TX)

    1980-01-01

    What is disclosed is a heat exchanger-accumulator for vaporizing a refrigerant or the like, characterized by an upright pressure vessel having a top, bottom and side walls; an inlet conduit eccentrically and sealingly penetrating through the top; a tubular overflow chamber disposed within the vessel and sealingly connected with the bottom so as to define an annular outer volumetric chamber for receiving refrigerant; a heat transfer coil disposed in the outer volumetric chamber for vaporizing the liquid refrigerant that accumulates there; the heat transfer coil defining a passageway for circulating an externally supplied heat exchange fluid; transferring heat efficiently from the fluid; and freely allowing vaporized refrigerant to escape upwardly from the liquid refrigerant; and a refrigerant discharge conduit penetrating sealingly through the top and traversing substantially the length of the pressurized vessel downwardly and upwardly such that its inlet is near the top of the pressurized vessel so as to provide a means for transporting refrigerant vapor from the vessel. The refrigerant discharge conduit has metering orifices, or passageways, penetrating laterally through its walls near the bottom, communicating respectively interiorly and exteriorly of the overflow chamber for controllably carrying small amounts of liquid refrigerant and oil to the effluent stream of refrigerant gas.

  12. Optimization of Heat Exchanger Cleaning 

    E-Print Network [OSTI]

    Siegell, J. H.

    1986-01-01

    EXCHANGER CLEANING Jeffrey H. Siegell Exxon Research and Engineering Company Florham Park, New Jersey ABSTRACT The performance of heat integration systems is quantified in terms of the amount of heat that is recovered. This decreases with time due... to increased fouling of the heat exchange surface. Using the "Total Fouling Related Expenses (TFRE)" approach, economic incentives for heat exchanger cleaning are evaluated using linear, exponential, and exponential finite decrease models of the heat...

  13. Heat distribution ceramic processing method

    DOE Patents [OSTI]

    Tiegs, Terry N. (Lenoir City, TN); Kiggans, Jr., James O. (Oak Ridge, TN)

    2001-01-01

    A multi-layered heat distributor system is provided for use in a microwave process. The multi-layered heat distributors includes a first inner layer of a high thermal conductivity heat distributor material, a middle insulating layer and an optional third insulating outer layer. The multi-layered heat distributor system is placed around the ceramic composition or article to be processed and located in a microwave heating system. Sufficient microwave energy is applied to provide a high density, unflawed ceramic product.

  14. Electrochemical heat engine

    DOE Patents [OSTI]

    Elliott, Guy R. B. (Los Alamos, NM); Holley, Charles E. (Alcalde, NM); Houseman, Barton L. (Cockeysville, MD); Sibbitt, Jr., Wilmer L. (Albuquerque, NM)

    1978-01-01

    Electrochemical heat engines produce electrochemical work, and mechanical motion is limited to valve and switching actions as the heat-to-work cycles are performed. The electrochemical cells of said heat engines use molten or solid electrolytes at high temperatures. One or more reactions in the cycle will generate a gas at high temperature which can be condensed at a lower temperature with later return of the condensate to electrochemical cells. Sodium, potassium, and cesium are used as the working gases for high temperature cells (above 600 K) with halogen gases or volatile halides being used at lower temperature. Carbonates and halides are used as molten electrolytes and the solid electrolyte in these melts can also be used as a cell separator.

  15. On the complexity of approximating a nash equilibrium

    E-Print Network [OSTI]

    Daskalakis, Constantinos

    2011-01-01

    We show that computing a relative---that is, multiplicative as opposed to additive---approximate Nash equilibrium in two-player games is PPAD-complete, even for constant values of the approximation. Our result is the first ...

  16. Approximations for the rotational excitation of molecules by atoms

    E-Print Network [OSTI]

    Chu, Shih-I; Dalgarno, A.

    1975-01-01

    The applicability of the effective close?coupling approximation of Rabitz and the centrifugal decoupling approximation of McGuire and Kouri is examined for a system which models the rotational excitation of molecular nitrogen in collisions...

  17. Report on some recent advances in Diophantine approximation

    E-Print Network [OSTI]

    Waldschmidt, Michel

    by linear forms · irrationality measures · transcendence criterion · criteria for algebraic inde- pendence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 Rational approximation to a real number . . . . . . . . . . . . . . . . . . . . . . . . 6 1, algebraic and simultaneous approximation to a single number

  18. Guest Editorial Sparse Approximations in Signal and Image Processing

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Guest Editorial Sparse Approximations in Signal and Image Processing Sparse approximation to solve many other signal processing problems, including blind source separation, feature extraction techniques to images as well as audio and biomedical signals, new efficient im- plementations of greedy

  19. Social Media: Heat #HeatSafety #BeatTheHeat #SummerSafety

    E-Print Network [OSTI]

    ; Facebook: Did you know the air temperature can actually feel hotter than what the thermometer reads to help the NWS build a WeatherReady Nation. Facebook: Heat is typically the leading cause.weather.gov/heat #HeatSafety #12; Facebook: Heat waves can be deadly! They can also happen anywhere in the U

  20. Optical heat flux gauge

    DOE Patents [OSTI]

    Noel, Bruce W. (Espanola, NM); Borella, Henry M. (Santa Barbara, CA); Cates, Michael R. (Oak Ridge, TN); Turley, W. Dale (Santa Barbara, CA); MacArthur, Charles D. (Clayton, OH); Cala, Gregory C. (Dayton, OH)

    1991-01-01

    A heat flux gauge comprising first and second thermographic phosphor layers separated by a layer of a thermal insulator, wherein each thermographic layer comprises a plurality of respective thermographic sensors in a juxtaposed relationship with respect to each other. The gauge may be mounted on a surface with the first thermographic phosphor in contact with the surface. A light source is directed at the gauge, causing the phosphors to luminesce. The luminescence produced by the phosphors is collected and its spectra analyzed in order to determine the heat flux on the surface. First and second phosphor layers must be different materials to assure that the spectral lines collected will be distinguishable.

  1. Solar industrial process heat

    SciTech Connect (OSTI)

    Lumsdaine, E.

    1981-04-01

    The aim of the assessment reported is to candidly examine the contribution that solar industrial process heat (SIPH) is realistically able to make in the near and long-term energy futures of the United States. The performance history of government and privately funded SIPH demonstration programs, 15 of which are briefly summarized, and the present status of SIPH technology are discussed. The technical and performance characteristics of solar industrial process heat plants and equipment are reviewed, as well as evaluating how the operating experience of over a dozen SIPH demonstration projects is influencing institutional acceptance and economoc projections. Implications for domestic energy policy and international implications are briefly discussed. (LEW)

  2. Air heating system

    DOE Patents [OSTI]

    Primeau, John J. (19800 Seminole Rd., Euclid, OH 44117)

    1983-03-01

    A self-starting, fuel-fired, air heating system including a vapor generator, a turbine, and a condenser connected in a closed circuit such that the vapor output from the vapor generator is conducted to the turbine and then to the condenser where it is condensed for return to the vapor generator. The turbine drives an air blower which passes air over the condenser for cooling the condenser. Also, a condensate pump is driven by the turbine. The disclosure is particularly concerned with the provision of heat exchanger and circuitry for cooling the condensed fluid output from the pump prior to its return to the vapor generator.

  3. Acoustical heat pumping engine

    DOE Patents [OSTI]

    Wheatley, J.C.; Swift, G.W.; Migliori, A.

    1983-08-16

    The disclosure is directed to an acoustical heat pumping engine without moving seals. A tubular housing holds a compressible fluid capable of supporting an acoustical standing wave. An acoustical driver is disposed at one end of the housing and the other end is capped. A second thermodynamic medium is disposed in the housing near to but spaced from the capped end. Heat is pumped along the second thermodynamic medium toward the capped end as a consequence both of the pressure oscillation due to the driver and imperfect thermal contact between the fluid and the second thermodynamic medium. 2 figs.

  4. Laboratory Heat Recovery System 

    E-Print Network [OSTI]

    Burrows, D. B.; Mendez, F. J.

    1981-01-01

    that they will be considerable. The system has been in successful operation since October 1979. 724 ESL-IE-81-04-123 Proceedings from the Third Industrial Energy Technology Conference Houston, TX, April 26-29, 1981 Conoco R&D West The award-winning laboratory heat-recovery... stream_source_info ESL-IE-81-04-123.pdf.txt stream_content_type text/plain stream_size 11112 Content-Encoding ISO-8859-1 stream_name ESL-IE-81-04-123.pdf.txt Content-Type text/plain; charset=ISO-8859-1 LABORATORY HEAT...

  5. Acoustical heat pumping engine

    DOE Patents [OSTI]

    Wheatley, John C. (Los Alamos, NM); Swift, Gregory W. (Los Alamos, NM); Migliori, Albert (Santa Fe, NM)

    1983-08-16

    The disclosure is directed to an acoustical heat pumping engine without moving seals. A tubular housing holds a compressible fluid capable of supporting an acoustical standing wave. An acoustical driver is disposed at one end of the housing and the other end is capped. A second thermodynamic medium is disposed in the housing near to but spaced from the capped end. Heat is pumped along the second thermodynamic medium toward the capped end as a consequence both of the pressure oscillation due to the driver and imperfect thermal contact between the fluid and the second thermodynamic medium.

  6. Absorption Heat Pumps | Department of Energy

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

    Absorption Heat Pumps Absorption Heat Pumps June 24, 2012 - 2:11pm Addthis Absorption heat pumps are essentially air-source heat pumps driven not by electricity, but by a heat...

  7. Tips: Heat Pumps | Department of Energy

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

    Heat Pumps Tips: Heat Pumps July 20, 2014 - 5:48pm Addthis Heat pumps can be a cost-effective choice in moderate climates, especially if you heat your home with electricity. Heat...

  8. Bond selective chemistry beyond the adiabatic approximation

    SciTech Connect (OSTI)

    Butler, L.J. [Univ. of Chicago, IL (United States)

    1993-12-01

    One of the most important challenges in chemistry is to develop predictive ability for the branching between energetically allowed chemical reaction pathways. Such predictive capability, coupled with a fundamental understanding of the important molecular interactions, is essential to the development and utilization of new fuels and the design of efficient combustion processes. Existing transition state and exact quantum theories successfully predict the branching between available product channels for systems in which each reaction coordinate can be adequately described by different paths along a single adiabatic potential energy surface. In particular, unimolecular dissociation following thermal, infrared multiphoton, or overtone excitation in the ground state yields a branching between energetically allowed product channels which can be successfully predicted by the application of statistical theories, i.e. the weakest bond breaks. (The predictions are particularly good for competing reactions in which when there is no saddle point along the reaction coordinates, as in simple bond fission reactions.) The predicted lack of bond selectivity results from the assumption of rapid internal vibrational energy redistribution and the implicit use of a single adiabatic Born-Oppenheimer potential energy surface for the reaction. However, the adiabatic approximation is not valid for the reaction of a wide variety of energetic materials and organic fuels; coupling between the electronic states of the reacting species play a a key role in determining the selectivity of the chemical reactions induced. The work described below investigated the central role played by coupling between electronic states in polyatomic molecules in determining the selective branching between energetically allowed fragmentation pathways in two key systems.

  9. A viscous-convective instability in laminar Keplerian thin discs. II. Anelastic approximation

    E-Print Network [OSTI]

    Shakura, N

    2015-01-01

    Using the anelastic approximation of linearised hydrodynamic equations, we investigate the development of axially symmetric small perturbations in thin Keplerian discs. The sixth-order dispersion equation is derived and numerically solved for different values of relevant physical parameters (viscosity, heat conductivity, disc semi-thickness and vertical structure). The analysis reveals the appearance of two overstable modes which split out from the classical Rayleigh inertial modes in a wide range of the parameters in both ionized and neutral gases. These modes have a viscous-convective nature and can serve as a seed for turbulence in astrophysical discs even in the absence of magnetic fields.

  10. Approximation Algorithms for Multi-criteria Traveling Salesman Problems

    E-Print Network [OSTI]

    Al Hanbali, Ahmad

    +3-42 +, respectively. Moreover, we design ran- domized approximation algorithms for multi-criteria () -ATSP (ratio 1 2. Therefore, we design randomized approximation schemes for multi-criteria cycle cover problems by showingApproximation Algorithms for Multi-criteria Traveling Salesman Problems Bodo Manthey1 and L

  11. Numerical Approximation of Vortex Density Evolution in a Superconductor.

    E-Print Network [OSTI]

    Styles, Vanessa

    Numerical Approximation of Vortex Density Evolution in a Superconductor. C.M. Elliott & V. Styles Abstract A #12;nite volume/element approximation of a mean #12;eld model of superconducting vortices in one approximations of a two-dimensional version of the mean #12;eld model of superconducting vortices considered

  12. Input-ouput approximation for nonlinear structural dynamics 

    E-Print Network [OSTI]

    Beaver, Stefanie Rene'

    2009-05-15

    . Nonlinear Assumed Model with Fixed Rotation Rate . 51 V NONLINEAR INPUT-OUTPUT APPROXIMATION . . . . . . 54 A. Algorithm Overview . . . . . . . . . . . . . . . . . . . . . 54 B. Linear Input-Output Approximation . . . . . . . . . . . . 57 C. Least Squares.... Quadratic Assumed Modes with Higher-Order Terms . 77 ix CHAPTER Page 2. Application of Nonlinear Input-Output Approxi- mation Algorithm . . . . . . . . . . . . . . . . . . . . 81 a. Linear Input-Output Approximation . . . . . . . 82 b. Least Squares...

  13. Technical Note Variational free energy and the Laplace approximation

    E-Print Network [OSTI]

    Daunizeau, Jean

    Technical Note Variational free energy and the Laplace approximation Karl Friston,a, Jérémie October 2006 This note derives the variational free energy under the Laplace approximation, with a focus. This is relevant when using the free energy as an approximation to the log-evidence in Bayesian model averaging

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

    E-Print Network [OSTI]

    Singh, K. P.

    1979-01-01

    CHARACTERISTICS OF A GENERALIZED DIVIDED FLrnJ HEAT EXCHANGER KRISHNA P. SINGH, CHIEF ENGINEER JOSEPH OAT CORPORATION 2500 Broadway, Camden, New Jersey 08104 ,l\\bstract The concept of a "Di vi ded-fl O~I" heat exchanger is general i zed by 1oca t i n...-Pass Split-Flow Shell Trans. of the ASME, Journal of Heat Transfer, pp 408-416, Aug. 1964. (4) Singh, K. P. and Holtz, ~I.J., "Generalization of the Split Flow Heat Exchanger - Geometry for Enhanced Heat Transfer", 18th National ASME/AICHE Heat Transfer...

  15. Insensitivity of Ion Motional Heating Rate to Trap Material over a Large Temperature Range

    E-Print Network [OSTI]

    J. Chiaverini; J. M. Sage

    2013-10-30

    We present measurements of trapped-ion motional-state heating rates in niobium and gold surface-electrode ion traps over a range of trap-electrode temperatures from approximately 4 K to room temperature (295 K) in a single apparatus. Using the sideband-ratio technique after resolved-sideband cooling of single ions to the motional ground state, we find low-temperature heating rates more than two orders of magnitude below the room-temperature values and approximately equal to the lowest measured heating rates in similarly-sized cryogenic traps. We find similar behavior in the two very different electrode materials, suggesting that the anomalous heating process is dominated by non-material-specific surface contaminants. Through precise control of the temperature of cryopumping surfaces, we also identify conditions under which elastic collisions with the background gas can lead to an apparent steady heating rate, despite rare collisions.

  16. Wastewater heat recovery apparatus

    DOE Patents [OSTI]

    Kronberg, J.W.

    1992-09-01

    A heat recovery system is described with a heat exchanger and a mixing valve. A drain trap includes a heat exchanger with an inner coiled tube, baffle plate, wastewater inlet, wastewater outlet, cold water inlet, and preheated water outlet. Wastewater enters the drain trap through the wastewater inlet, is slowed and spread by the baffle plate, and passes downward to the wastewater outlet. Cold water enters the inner tube through the cold water inlet and flows generally upward, taking on heat from the wastewater. This preheated water is fed to the mixing valve, which includes a flexible yoke to which are attached an adjustable steel rod, two stationary zinc rods, and a pivoting arm. The free end of the arm forms a pad which rests against a valve seat. The rods and pivoting arm expand or contract as the temperature of the incoming preheated water changes. The zinc rods expand more than the steel rod, flexing the yoke and rotating the pivoting arm. The pad moves towards the valve seat as the temperature of the preheated water rises, and away as the temperature falls, admitting a variable amount of hot water to maintain a nearly constant average process water temperature. 6 figs.

  17. Industrial Waste Heat Recovery 

    E-Print Network [OSTI]

    Ward, M. E.; Solomon, N. G.; Tabb, E. S.

    1980-01-01

    was that the upper material temperature limit of 1500oF is state-of-the-art for recuperators operating in an oxidizing environment produced by the com-bustion of Diesel No.2. A full size counter axial flow metal heat exchanger test module has successfully completed...

  18. Wastewater heat recovery apparatus

    DOE Patents [OSTI]

    Kronberg, James W. (108 Independent Blvd., Aiken, SC 29801)

    1992-01-01

    A heat recovery system with a heat exchanger and a mixing valve. A drain trap includes a heat exchanger with an inner coiled tube, baffle plate, wastewater inlet, wastewater outlet, cold water inlet, and preheated water outlet. Wastewater enters the drain trap through the wastewater inlet, is slowed and spread by the baffle plate, and passes downward to the wastewater outlet. Cold water enters the inner tube through the cold water inlet and flows generally upward, taking on heat from the wastewater. This preheated water is fed to the mixing valve, which includes a flexible yoke to which are attached an adjustable steel rod, two stationary zinc rods, and a pivoting arm. The free end of the arm forms a pad which rests against a valve seat. The rods and pivoting arm expand or contract as the temperature of the incoming preheated water changes. The zinc rods expand more than the steel rod, flexing the yoke and rotating the pivoting arm. The pad moves towards the valve seat as the temperature of the preheated water rises, and away as the temperature falls, admitting a variable amount of hot water to maintain a nearly constant average process water temperature.

  19. Heat exchange assembly

    DOE Patents [OSTI]

    Lowenstein, Andrew; Sibilia, Marc; Miller, Jeffrey; Tonon, Thomas S.

    2004-06-08

    A heat exchange assembly comprises a plurality of plates disposed in a spaced-apart arrangement, each of the plurality of plates includes a plurality of passages extending internally from a first end to a second end for directing flow of a heat transfer fluid in a first plane, a plurality of first end-piece members equaling the number of plates and a plurality of second end-piece members also equaling the number of plates, each of the first and second end-piece members including a recessed region adapted to fluidly connect and couple with the first and second ends of the plate, respectively, and further adapted to be affixed to respective adjacent first and second end-piece members in a stacked formation, and each of the first and second end-piece members further including at least one cavity for enabling entry of the heat transfer fluid into the plate, exit of the heat transfer fluid from the plate, or 180.degree. turning of the fluid within the plate to create a serpentine-like fluid flow path between points of entry and exit of the fluid, and at least two fluid conduits extending through the stacked plurality of first and second end-piece members for providing first fluid connections between the parallel fluid entry points of adjacent plates and a fluid supply inlet, and second fluid connections between the parallel fluid exit points of adjacent plates and a fluid discharge outlet so that the heat transfer fluid travels in parallel paths through each respective plate.

  20. The Design of an Open Rankine-Cycle Industrial Heat Pump 

    E-Print Network [OSTI]

    Leibowitz, H. M.; Chaudoir, D. W.

    1981-01-01

    from a simulated 150?F clean waste water stream. The plant is based on the Open-Dpen? heat pump concept, i.e., no system evapo rator or condenser. The water vapor is generated by a flash evaporation process. In this heat pump system, shown... schematically in Figure 2, the waste stream supplies the heat energy for the system and also serves as the heat pump working flUid. The waste water stream is directed to a flash evapo rator, where approximately 0.5 to 1% of the stream is vaporized...

  1. TRANSPARENT HEAT MIRRORS FOR PASSIVE SOLAR HEATING APPLICATIONS

    E-Print Network [OSTI]

    Selkowitz, S.

    2011-01-01

    surfaces in a passive solar-heated building is to maximizeBuildings and Community Systems. -i- TRANSPARENT HEATING MIRRORS FOR PASSIVEpassive solar systems. Architecturally, a window is a very complex building

  2. Low Level Heat Recovery Through Heat Pumps and Vapor Recompression 

    E-Print Network [OSTI]

    Gilbert, J.

    1980-01-01

    The intent of this paper is to examine the methods and economics of recovering low level heat through heat pumps and vapor recompression. Actual commercially available equipment is considered to determine the near-term and future economic viability...

  3. Modeling of Heat Transfer in Geothermal Heat Exchangers 

    E-Print Network [OSTI]

    Cui, P.; Man, Y.; Fang, Z.

    2006-01-01

    Ground-coupled heat pump (GCHP) systems have been gaining increasing popularity for space conditioning in residential and commercial buildings. The geothermal heat exchanger (GHE) is devised for extraction or injection of thermal energy from...

  4. Metal-Organic Heat Carrier Nanofluids

    SciTech Connect (OSTI)

    McGrail, B. Peter; Thallapally, Praveen K.; Blanchard, Jeremy; Nune, Satish K.; Jenks, Jeromy WJ; Dang, Liem X.

    2013-09-01

    Nanofluids, dispersions of metal or oxide nanoparticles in a base working fluid, are being intensively studied due to improvements they offer in thermal properties of the working fluid. However, these benefits have been erratically demonstrated and proven impacts on thermal conductivity are modest and well described from long-established effective medium theory. In this paper, we describe a new class of metal-organic heat carrier (MOHC) nanofluid that offers potential for a larger performance boost in thermal vapor-liquid compression cycles. MOHCs are nanophase porous coordination solids designed to reversibly uptake the working fluid molecules in which the MOHCs are suspended. Additional heat can be extracted in a heat exchanger or solar collector from the endothermic enthalpy of desorption, which is then released as the nanofluid transits through a power generating device such as a turboexpander. Calculations for an R123 MOHC nanofluid indicated potential for up to 15% increase in power output. Capillary tube experiments show that liquid-vapor transitions occur without nanoparticle deposition on the tube walls provided entrance Reynolds number exceeds approximately 100.

  5. Influence of Heat Transmission Mode on Heating Rates and on the Selection of Patches for Heating in a Mediterranean Lizard

    E-Print Network [OSTI]

    Carrascal, Luis M.

    369 Influence of Heat Transmission Mode on Heating Rates and on the Selection of Patches the role of heat trans- mission modes on heating rates and on the selection of sites for heating a significant effect on the heating rate, with heat gain per unit of time being faster at the higher operative

  6. AN EFFICIENT SECOND ORDER IN TIME SCHEME FOR APPROXIMATING LONG TIME STATISTICAL PROPERTIES OF

    E-Print Network [OSTI]

    AN EFFICIENT SECOND ORDER IN TIME SCHEME FOR APPROXIMATING LONG TIME STATISTICAL PROPERTIES of the following efficient second order in time scheme for the 2D Navier-Stokes equation in a periodic box: 3n+1 - 4n + n-1 2k + (2n - n-1 ) · (2n - n-1 ) - n+1 = fn+1 , -n = n . The scheme is a combination of a 2

  7. Development of a 75-kW heat-pipe receiver for solar heat-engines

    SciTech Connect (OSTI)

    Adkins, D.R.; Andraka, C.E.; Moss, T.A.

    1995-05-01

    A program is now underway to develop commercial power conversion systems that use parabolic dish mirrors in conjunction with Stirling engines to convert solar energy to electric power. In early prototypes, the solar concentrator focused light directly on the heater tubes of the Stirling engine. Liquid-metal heat-pipes are now being developed to transfer energy from the focus of the solar concentrator to the heater tubes of the engine. The dome-shaped heat-pipe receivers are approximately one-half meters in diameter and up to 77-kW of concentrated solar energy is delivered to the absorber surface. Over the past several years, Sandia National Laboratories, through the sponsorship of the Department of Energy, has conducted a major program to explore receiver designs and identify suitable wick materials. A high-flux bench-scale system has been developed to test candidate wick designs, and full-scale systems have been tested on an 11-meter test-bed solar concentrator. Procedures have also been developed in this program to measure the properties of wick materials, and an extensive data-base on wick materials for high temperature heat pipes has been developed. This paper provides an overview of the receiver development program and results from some of the many heat-pipe tests.

  8. Fast reactor power plant design having heat pipe heat exchanger

    DOE Patents [OSTI]

    Huebotter, P.R.; McLennan, G.A.

    1984-08-30

    The invention relates to a pool-type fission reactor power plant design having a reactor vessel containing a primary coolant (such as liquid sodium), and a steam expansion device powered by a pressurized water/steam coolant system. Heat pipe means are disposed between the primary and water coolants to complete the heat transfer therebetween. The heat pipes are vertically oriented, penetrating the reactor deck and being directly submerged in the primary coolant. A U-tube or line passes through each heat pipe, extended over most of the length of the heat pipe and having its walls spaced from but closely proximate to and generally facing the surrounding walls of the heat pipe. The water/steam coolant loop includes each U-tube and the steam expansion device. A heat transfer medium (such as mercury) fills each of the heat pipes. The thermal energy from the primary coolant is transferred to the water coolant by isothermal evaporation-condensation of the heat transfer medium between the heat pipe and U-tube walls, the heat transfer medium moving within the heat pipe primarily transversely between these walls.

  9. Fast reactor power plant design having heat pipe heat exchanger

    DOE Patents [OSTI]

    Huebotter, Paul R. (Western Springs, IL); McLennan, George A. (Downers Grove, IL)

    1985-01-01

    The invention relates to a pool-type fission reactor power plant design having a reactor vessel containing a primary coolant (such as liquid sodium), and a steam expansion device powered by a pressurized water/steam coolant system. Heat pipe means are disposed between the primary and water coolants to complete the heat transfer therebetween. The heat pipes are vertically oriented, penetrating the reactor deck and being directly submerged in the primary coolant. A U-tube or line passes through each heat pipe, extended over most of the length of the heat pipe and having its walls spaced from but closely proximate to and generally facing the surrounding walls of the heat pipe. The water/steam coolant loop includes each U-tube and the steam expansion device. A heat transfer medium (such as mercury) fills each of the heat pipes. The thermal energy from the primary coolant is transferred to the water coolant by isothermal evaporation-condensation of the heat transfer medium between the heat pipe and U-tube walls, the heat transfer medium moving within the heat pipe primarily transversely between these walls.

  10. ELECTRIC CO-HEATING: A METHOD FOR EVALUATING SEASONAL HEATING EFFICIENCIES AND HEAT LOSS RATES IN DWELLINGS

    E-Print Network [OSTI]

    Modera, M.P.

    2012-01-01

    the measured values for heat transmission and air leakagethe contribution by heat transmission alone through theheating efficiency, heat transmission coefficient and air

  11. Development of a 2 MW CW Waterload for Electron Cyclotron Heating Systems

    SciTech Connect (OSTI)

    R. Lawrence,Ives; Maxwell Mizuhara; George Collins; Jeffrey Neilson; Philipp Borchard

    2012-11-09

    Calabazas Creek Research, Inc. developed a load capable of continuously dissipating 2 MW of RF power from gyrotrons. The input uses HE11 corrugated waveguide and a rotating launcher to uniformly disperse the power over the lossy surfaces in the load. This builds on experience with a previous load designed to dissipate 1 MW of continuous RF power. The 2 MW load uses more advanced RF dispersion to double the capability in the same size device as the 1 MW load. The new load reduces reflected power from the load to significantly less than 1 %. This eliminates requirements for a preload to capture reflected power. The program updated control electronics that provides all required interlocks for operation and measurement of peak and average power. The program developed two version of the load. The initial version used primarily anodized aluminum to reduce weight and cost. The second version used copper and stainless steel to meet specifications for the ITER reactor currently under construction in France. Tests of the new load at the Japanese Atomic Energy Agency confirmed operation of the load to a power level of 1 MW, which is the highest power currently available for testing the load. Additional tests will be performed at General Atomics in spring 2013. The U.S. ITER organization will test the copper/stainless steel version of the load in December 2012 or early in 2013. Both loads are currently being marketed worldwide.

  12. Challenges in Industrial Heat Recovery 

    E-Print Network [OSTI]

    Dafft, T.

    2007-01-01

    This presentation will address several completed and working projects involving waste heat recovery in a chemical plant. Specific examples will be shown and some of the challenges to successful implementation and operation of heat recovery projects...

  13. Faculty Positions Heat Transfer and

    E-Print Network [OSTI]

    Faculty Positions Heat Transfer and Thermal/Energy Sciences Naval Postgraduate School Monterey-track faculty position at the assistant professor level in the areas of Heat Transfer and Thermal/Fluid Sciences

  14. Central Multifamily Water Heating Systems

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Building America Program is hosting a no-cost, webinar-based training on Central Multifamily Water Heating Systems. The webinar will focus the effective use of central heat pump water heaters...

  15. Phase Change Heat Transfer Device for Process Heat Applications

    SciTech Connect (OSTI)

    Piyush Sabharwall; Mike Patterson; Vivek Utgikar; Fred Gunnerson

    2010-10-01

    The next generation nuclear plant (NGNP) will most likely produce electricity and process heat, with both being considered for hydrogen production. To capture nuclear process heat, and transport it to a distant industrial facility requires a high temperature system of heat exchangers, pumps and/or compressors. The heat transfer system is particularly challenging not only due to the elevated temperatures (up to approx.1300 K) and industrial scale power transport (=50MW), but also due to a potentially large separation distance between the nuclear and industrial plants (100+m) dictated by safety and licensing mandates. The work reported here is the preliminary analysis of two-phase thermosyphon heat transfer performance with alkali metals. A thermosyphon is a thermal device for transporting heat from one point to another with quite extraordinary properties. In contrast to single-phased forced convective heat transfer via ‘pumping a fluid’, a thermosyphon (also called a wickless heat pipe) transfers heat through the vaporization/condensing process. The condensate is further returned to the hot source by gravity, i.e., without any requirement of pumps or compressors. With this mode of heat transfer, the thermosyphon has the capability to transport heat at high rates over appreciable distances, virtually isothermally and without any requirement for external pumping devices. Two-phase heat transfer by a thermosyphon has the advantage of high enthalpy transport that includes the sensible heat of the liquid, the latent heat of vaporization, and vapor superheat. In contrast, single-phase forced convection transports only the sensible heat of the fluid. Additionally, vapor-phase velocities within a thermosyphon are much greater than single-phase liquid velocities within a forced convective loop. Thermosyphon performance can be limited by the sonic limit (choking) of vapor flow and/or by condensate entrainment. Proper thermosyphon requires analysis of both.

  16. Optical heat flux gauge

    DOE Patents [OSTI]

    Noel, B.W.; Borella, H.M.; Cates, M.R.; Turley, W.D.; MacArthur, C.D.; Cala, G.C.

    1991-04-09

    A heat flux gauge is disclosed comprising first and second thermographic phosphor layers separated by a layer of a thermal insulator, wherein each thermographic layer comprises a plurality of respective thermographic sensors in a juxtaposed relationship with respect to each other. The gauge may be mounted on a surface with the first thermographic phosphor in contact with the surface. A light source is directed at the gauge, causing the phosphors to luminesce. The luminescence produced by the phosphors is collected and its spectra analyzed in order to determine the heat flux on the surface. First and second phosphor layers must be different materials to assure that the spectral lines collected will be distinguishable. 9 figures.

  17. Superradiant Quantum Heat Engine

    E-Print Network [OSTI]

    Ali Ü. C. Hardal; Özgür E. Müstecapl?oglu

    2015-07-16

    Quantum physics revolutionized classical disciplines of mechanics, statistical physics, and electrodynamics. One branch of scientific knowledge however seems untouched: thermodynamics. Major motivation behind thermodynamics is to develop efficient heat engines. Technology has a trend to miniaturize engines, reaching to quantum regimes. Development of quantum heat engines (QHEs) requires emerging field of quantum thermodynamics. Studies of QHEs debate whether quantum coherence can be used as a resource. We explore an alternative where it can function as an effective catalyst. We propose a QHE which consists of a photon gas inside an optical cavity as the working fluid and quantum coherent atomic clusters as the fuel. Utilizing the superradiance, where a cluster can radiate quadratically faster than a single atom, we show that the work output becomes proportional to the square of the number of the atoms. In addition to practical value of cranking up QHE, our result is a fundamental difference of a quantum fuel from its classical counterpart.

  18. Superradiant Quantum Heat Engine

    E-Print Network [OSTI]

    Ali Ü. C. Hardal; Özgür E. Müstecapl?oglu

    2015-04-22

    Quantum physics revolutionized classical disciplines of mechanics, statistical physics, and electrodynamics. One branch of scientific knowledge however seems untouched: thermodynamics. Major motivation behind thermodynamics is to develop efficient heat engines. Technology has a trend to miniaturize engines, reaching to quantum regimes. Development of quantum heat engines (QHEs) requires emerging field of quantum thermodynamics. Studies of QHEs debate whether quantum coherence can be used as a resource. We explore an alternative where it can function as an effective catalyst. We propose a QHE which consists of a photon gas inside an optical cavity as the working fluid and quantum coherent atomic clusters as the fuel. Utilizing the superradiance, where a cluster can radiate quadratically faster than a single atom, we show that the work output becomes proportional to the square of the number of the atoms. In addition to practical value of cranking up QHE, our result is a fundamental difference of a quantum fuel from its classical counterpart.

  19. Heat transport system

    DOE Patents [OSTI]

    Harkness, Samuel D. (McMurray, PA)

    1982-01-01

    A falling bed of ceramic particles receives neutron irradiation from a neutron-producing plasma and thereby transports energy as heat from the plasma to a heat exchange location where the ceramic particles are cooled by a gas flow. The cooled ceramic particles are elevated to a location from which they may again pass by gravity through the region where they are exposed to neutron radiation. Ceramic particles of alumina, magnesia, silica and combinations of these materials are contemplated as high-temperature materials that will accept energy from neutron irradiation. Separate containers of material incorporating lithium are exposed to the neutron flux for the breeding of tritium that may subsequently be used in neutron-producing reactions. The falling bed of ceramic particles includes velocity partitioning between compartments near to the neutron-producing plasma and compartments away from the plasma to moderate the maximum temperature in the bed.

  20. Heat transfer probe

    DOE Patents [OSTI]

    Frank, Jeffrey I.; Rosengart, Axel J.; Kasza, Ken; Yu, Wenhua; Chien, Tai-Hsin; Franklin, Jeff

    2006-10-10

    Apparatuses, systems, methods, and computer code for, among other things, monitoring the health of samples such as the brain while providing local cooling or heating. A representative device is a heat transfer probe, which includes an inner channel, a tip, a concentric outer channel, a first temperature sensor, and a second temperature sensor. The inner channel is configured to transport working fluid from an inner inlet to an inner outlet. The tip is configured to receive at least a portion of the working fluid from the inner outlet. The concentric outer channel is configured to transport the working fluid from the inner outlet to an outer outlet. The first temperature sensor is coupled to the tip, and the second temperature sensor spaced apart from the first temperature sensor.

  1. [Waste water heat recovery system

    SciTech Connect (OSTI)

    Not Available

    1993-04-28

    The production capabilities for and field testing of the heat recovery system are described briefly. Drawings are included.

  2. Characterization of industrial process waste heat and input heat streams

    SciTech Connect (OSTI)

    Wilfert, G.L.; Huber, H.B.; Dodge, R.E.; Garrett-Price, B.A.; Fassbender, L.L.; Griffin, E.A.; Brown, D.R.; Moore, N.L.

    1984-05-01

    The nature and extent of industrial waste heat associated with the manufacturing sector of the US economy are identified. Industry energy information is reviewed and the energy content in waste heat streams emanating from 108 energy-intensive industrial processes is estimated. Generic types of process equipment are identified and the energy content in gaseous, liquid, and steam waste streams emanating from this equipment is evaluated. Matchups between the energy content of waste heat streams and candidate uses are identified. The resultant matrix identifies 256 source/sink (waste heat/candidate input heat) temperature combinations. (MHR)

  3. Heat and mass transfer considerations in advanced heat pump systems

    SciTech Connect (OSTI)

    Panchal, C.B.; Bell, K.J.

    1992-08-01

    Advanced heat-pump cycles are being investigated for various applications. However, the working media and associated thermal design aspects require new concepts for maintaining high thermal effectiveness and phase equilibrium for achieving maximum possible thermodynamic advantages. In the present study, the heat- and mass-transfer processes in two heat-pump systems -- those based on absorption processes, and those using refrigerant mixtures -- are analyzed. The major technical barriers for achieving the ideal performance predicted by thermodynamic analysis are identified. The analysis provides general guidelines for the development of heat- and mass-transfer equipment for advanced heat-pump systems.

  4. Heat and mass transfer considerations in advanced heat pump systems

    SciTech Connect (OSTI)

    Panchal, C.B.; Bell, K.J.

    1992-01-01

    Advanced heat-pump cycles are being investigated for various applications. However, the working media and associated thermal design aspects require new concepts for maintaining high thermal effectiveness and phase equilibrium for achieving maximum possible thermodynamic advantages. In the present study, the heat- and mass-transfer processes in two heat-pump systems -- those based on absorption processes, and those using refrigerant mixtures -- are analyzed. The major technical barriers for achieving the ideal performance predicted by thermodynamic analysis are identified. The analysis provides general guidelines for the development of heat- and mass-transfer equipment for advanced heat-pump systems.

  5. Energy 101: Geothermal Heat Pumps

    SciTech Connect (OSTI)

    None

    2011-01-01

    An energy-efficient heating and cooling alternative, the geothermal heat pump system moves heat from the ground to a building (or from a building to the ground) through a series of flexible pipe "loops" containing water. This edition of Energy 101 explores the benefits Geothermal and the science behind how it all comes together.

  6. Energy 101: Geothermal Heat Pumps

    ScienceCinema (OSTI)

    None

    2013-05-29

    An energy-efficient heating and cooling alternative, the geothermal heat pump system moves heat from the ground to a building (or from a building to the ground) through a series of flexible pipe "loops" containing water. This edition of Energy 101 explores the benefits Geothermal and the science behind how it all comes together.

  7. 4065 (RP-664) Heat Transfer

    E-Print Network [OSTI]

    of roomsurface-to-air heat transmission is dependentonan accurateestimateof the filmcoefficient. Forty- eight4065 (RP-664) Convective Energy and Heat Transfer Thermal Load in Building Calculations Daniel E convection film coefficients significantly underpredict the rate of surface convective heat 'transfer

  8. Confocal Heat Pump Mike Lampton

    E-Print Network [OSTI]

    California at Berkeley, University of

    Confocal Heat Pump Mike Lampton Space Sciences Lab, UC Berkeley Originally posted 1 April 2014 heat pump since it is based on ideas stemming from confocal ellipsoids. 2 Confocal Ellipsoids I begin symmetrical. There are infinitely many other possibilities. Each is reciprocal. 3 Confocal Heat Pump

  9. temperature heat pumps applied to

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    Very high- temperature heat pumps applied to energy efficiency in industry Application of industrial heat pumps June 21 th 2012 J-L Peureux, E. Sapora, D. Bobelin EDF R&D #12;Achema 2012 Frankfurt There are thermal requirements in the industrial plant Treq Heat exchanger = Cons ~ 0 CO2 ~ -100% Treq

  10. 5. Heat transfer Ron Zevenhoven

    E-Print Network [OSTI]

    Zevenhoven, Ron

    Three heat transfer mechanisms Conduction Convection Radiation 2/120 Pic: BÖ88 Åbo Akademi University1/120 5. Heat transfer Ron Zevenhoven Åbo Akademi University Thermal and Flow Engineering / Värme | Thermal and Flow Engineering | 20500 Turku | Finland #12;3/120 5.1 Conductive heat transfer Åbo Akademi

  11. Heat Pipes: An Industrial Application 

    E-Print Network [OSTI]

    Murray, F.

    1984-01-01

    pipe exchangers, an industrial case history is presented. The case history involves a retrofit project which added heat pipes to five natural draft process heaters with a combined heat duty of 150 M Btu/hr. A heat recovery of 15 M Btu/hr has resulted...

  12. Spring 2014 Heat Transfer -1

    E-Print Network [OSTI]

    Virginia Tech

    Spring 2014 1 Heat Transfer - 1 Consider a cylindrical nuclear fuel rod of length L and diameter df and the tube at a rate m , and the outer surface of the tube is well insulated. Heat generation occurs within. The specific heat of water pc , and the thermal conductivity of the fuel rod fk are constants. The system

  13. Heat Waves, Global Warming, and Mitigation

    E-Print Network [OSTI]

    Carlson, Ann E.

    2008-01-01

    Heat Waves, Global Warming, and Mitigation Ann E. Carlson*2008]HEAT WAVES, GLOBAL WARMING, AND MITIGATION 175 stroke2001). 2008]HEAT WAVES, GLOBAL WARMING, AND MITIGATION 177

  14. Urban Surfaces and Heat Island Mitigation Potentials

    E-Print Network [OSTI]

    Akbari, Hashem

    2008-01-01

    Finster. 2000. “The Urban Heat Island, Photochemical Smog,2001. “EPA/NASA Urban Heat Island Pilot Project,” GlobalSystem Urban Surfaces and Heat Island Mitigation Potentials

  15. CONTROL SYSTEM FOR SOLAR HEATING and COOLING

    E-Print Network [OSTI]

    Dols, C.

    2010-01-01

    water (solar heated, boosted, or heated entirely in the auxiliary heater)for the solar-heated hot water. This heater can be seen in

  16. Research & Development Roadmap: Emerging Water Heating Technologies...

    Energy Savers [EERE]

    Water Heating Technologies Research & Development Roadmap: Emerging Water Heating Technologies The Research and Development (R&D) Roadmap for Emerging Water Heating Technologies...

  17. CONTROL SYSTEM FOR SOLAR HEATING and COOLING

    E-Print Network [OSTI]

    Dols, C.

    2010-01-01

    operating solar heating and cooling systems covering a widepractical heating and cooling system configurations andexperimental heating and cooling system, the main purpose of

  18. Biomass Derivatives Competitive with Heating Oil Costs.

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

    Biomass Derivatives Competitive with Heating Oil Costs Transportation fuel Heat or electricity * Data are from literature, except heating oil is adjusted from 2011 winter average *...

  19. Home Heating Systems | Department of Energy

    Office of Environmental Management (EM)

    separately, many homes use the following approaches: Active Solar Heating Uses the sun to heat either air or liquid and can serve as a supplemental heat source. Electric...

  20. Distributed Generation with Heat Recovery and Storage

    E-Print Network [OSTI]

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

    2005-01-01

    Generation with Heat Recovery and Storage ‡ Afzal Sgeneration unit with heat recovery for space and watergeneration unit with heat recovery for space and water

  1. Distributed Generation with Heat Recovery and Storage

    E-Print Network [OSTI]

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

    2008-01-01

    Distributed Generation with Heat Recovery and Storage AfzalGeneration with Heat Recovery and Storage Manuscript Numberhere in order to focus on heat recovery and storage) utility

  2. A mathematical model for infiltration heat recovery

    E-Print Network [OSTI]

    Buchanan, C.R.; Sherman, M.H.

    2000-01-01

    Simulation of Infiltration Heat Recovery”, 19 th AIVC Annualfor infiltration heat recovery could easily be incorporatedSimplified Infiltration Heat Recovery Model ……………………17

  3. HEAT AND MOISTURE TRANSFER THROUGH CLOTHING

    E-Print Network [OSTI]

    Voelker, Conrad; Hoffmann, Sabine; Kornadt, Oliver; Arens, Edward; Zhang, Hui; Huizenga, Charlie

    2009-01-01

    R. C. Eberhart (ed), Heat transfer in medicine and biology.between convective heat transfer and mass transferConvective and radiative heat transfer coefficients for

  4. Heat and moisture transfer through clothing

    E-Print Network [OSTI]

    Voelker, Conrad; Hoffmann, Sabine; Kornadt, Oliver; Arens, Edward; Zhang, Hui; Huizenga, Charlie

    2009-01-01

    R. C. Eberhart (ed), Heat transfer in medicine and biology.Convective and radiative heat transfer coefficients forbetween convective heat transfer and mass transfer

  5. Safe Approximations of Chance Constraints Using Historical Data

    E-Print Network [OSTI]

    2015-01-11

    that does not require the assumption that certain moments are known. Moreover, it uses ...... alents: An approach to stochastic programming of heating oil.

  6. A New Partial Sample Average Approximation Method for Chance ...

    E-Print Network [OSTI]

    2014-10-13

    Under the assumption that we can sample from the distribution F, the scenario ...... certainty equivalents: an approach to stochastic programming of heating oil.

  7. Innovative Miniaturized Heat Pumps for Buildings: Modular Thermal Hub for Building Heating, Cooling and Water Heating

    SciTech Connect (OSTI)

    None

    2010-09-01

    BEETIT Project: Georgia Tech is using innovative components and system design to develop a new type of absorption heat pump. Georgia Tech’s new heat pumps are energy efficient, use refrigerants that do not emit greenhouse gases, and can run on energy from combustion, waste heat, or solar energy. Georgia Tech is leveraging enhancements to heat and mass transfer technology possible in microscale passages and removing hurdles to the use of heat-activated heat pumps that have existed for more than a century. Use of microscale passages allows for miniaturization of systems that can be packed as monolithic full-system packages or discrete, distributed components enabling integration into a variety of residential and commercial buildings. Compared to conventional heat pumps, Georgia Tech’s design innovations will create an absorption heat pump that is much smaller, has higher energy efficiency, and can also be mass produced at a lower cost and assembly time.

  8. Optimal Heat Collection Element Shapes for Parabolic Trough Concentrators

    SciTech Connect (OSTI)

    Bennett, C

    2007-11-15

    For nearly 150 years, the cross section of the heat collection tubes used at the focus of parabolic trough solar concentrators has been circular. This type of tube is obviously simple and easily fabricated, but it is not optimal. It is shown in this article that the optimal shape, assuming a perfect parabolic figure for the concentrating mirror, is instead oblong, and is approximately given by a pair of facing parabolic segments.

  9. Mixed convection heat transfer to and from a horizontal cylinder in cross-flow with heating from below.

    SciTech Connect (OSTI)

    Greif, Ralph (University of California, Berkeley, CA); Evans, Gregory Herbert; Kearney, Sean Patrick (Sandia National Laboratories, Albuquerque, NM); Laskowski, Gregory Michael

    2006-02-01

    Heat transfer to and from a circular cylinder in a cross-flow of water at low Reynolds number was studied both experimentally and numerically. The experiments were carried out in a high aspect ratio water channel. The test section inflow temperature and velocity, channel lower surface temperature and cylinder surface temperature were controlled to yield either laminar or turbulent flow for a desired Richardson number. When the lower surface was unheated, the temperatures of the lower surface and water upstream of the cylinder were maintained approximately equal and the flow was laminar. When the lower surface was heated, turbulence intensities as high as 20% were measured several cylinder diameters upstream of the cylinder due to turbulent thermal plumes produced by heating the lower surface. Variable property, two-dimensional simulations were undertaken using a variant of the u{sup 2}-f turbulence model with buoyancy production of turbulence accounted for by a simple gradient diffusion model. Predicted and measured heat flux distributions around the cylinder are compared for values of the Richardson number, Gr{sub d}/Re{sub d}{sup 2} from 0.3 to 9.3. For laminar flow, the predicted and measured heat flux results agreed to within the experimental uncertainty. When the lower surface was heated, and the flow was turbulent, there was qualitative agreement between predicted and measured heat flux distributions around the cylinder. However the predicted spatially averaged Nusselt number was from 37% to 53% larger than the measured spatially averaged Nusselt number. Additionally, spatially averaged Nusselt numbers are compared to correlations in the literature for mixed convection heat transfer to/from cylinders in cross-flow. The results presented here are larger than the correlation values. This is believed to be due to the effects of buoyancy-induced turbulence resulting from heating the lower surface and the proximity of the cylinder to that surface.

  10. Automating approximate Bayesian computation by local linear regression

    E-Print Network [OSTI]

    Thornton, Kevin R

    2009-01-01

    computation by local linear regression Kevin R Thorntonof ABC based on using a linear regression to approximate theimplements the local linear-regression approach to ABC. The

  11. The Numerical Approximation of Solutions of Partial Differential ...

    E-Print Network [OSTI]

    2009-05-05

    i.e., instead of thinking of the approximate solution as being linear between .... Consider the mildly nonlinear two-point boundary problem given by. ?(aux )x + c(

  12. How to Solve Schroedinger Problems by Approximating the Potential Function

    SciTech Connect (OSTI)

    Ledoux, Veerle; Van Daele, Marnix

    2010-09-30

    We give a survey over the efforts in the direction of solving the Schroedinger equation by using piecewise approximations of the potential function. Two types of approximating potentials have been considered in the literature, that is piecewise constant and piecewise linear functions. For polynomials of higher degree the approximating problem is not so easy to integrate analytically. This obstacle can be circumvented by using a perturbative approach to construct the solution of the approximating problem, leading to the so-called piecewise perturbation methods (PPM). We discuss the construction of a PPM in its most convenient form for applications and show that different PPM versions (CPM,LPM) are in fact equivalent.

  13. Approximation Algorithms for the Fault-Tolerant Facility Placement Problem

    E-Print Network [OSTI]

    Yan, Li

    2013-01-01

    5.2 Algorithm ECHS with Ratio5.3 Algorithm EBGS with RatioFormulation 2.1.3 Approximation Algorithms . 2.1.4 Bifactor

  14. ANALOG QUANTUM NEURON FOR FUNCTIONS APPROXIMATION A. EZHOV; A...

    Office of Scientific and Technical Information (OSTI)

    FOR FUNCTIONS APPROXIMATION A. EZHOV; A. KHROMOV; G. BERMAN 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; IMPLEMENTATION; NERVE CELLS; WAVEGUIDES We describe a system able...

  15. Heat transport within the Earth

    E-Print Network [OSTI]

    Herndon, J Marvin

    2011-01-01

    Numerous attempts have been made to interpret Earth's dynamic processes based upon heat transport concepts derived from ordinary experience. But, ordinary experience can be misleading, especially when underlain by false assumptions. Geodynamic considerations traditionally have embraced three modes of heat transport: conduction, convection, and radiation. Recently, I introduced a fourth, "mantle decompression thermal tsunami" that, I submit, is responsible for emplacing heat at the base of the Earth's crust. Here, I review thermal transport within the Earth and speculate that there might be a fifth mode: "heat channeling", involving heat transport from the core to "hot-spots" such as those that power the Hawaiian Islands and Iceland.

  16. Waste heat: Utilization and management

    SciTech Connect (OSTI)

    Sengupta, S.; Lee, S.S.

    1983-01-01

    This book is a presentation on waste heat management and utilization. Topics covered include cogeneration, recovery technology, low grade heat recovery, heat dispersion models, and ecological effects. The book focuses on the significant fraction of fuel energy that is rejected and expelled into the environment either as industrial waste or as a byproduct of installation/equipment operation. The feasibility of retrieving this heat and energy is covered, including technical aspects and potential applications. Illustrations demonstrate that recovery methods have become economical due to recent refinements. The book includes theory and practice concerning waste heat management and utilization.

  17. Absorption-heat-pump system

    DOE Patents [OSTI]

    Grossman, G.; Perez-Blanco, H.

    1983-06-16

    An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

  18. Ly? heating of inhomogeneous high-redshift intergalactic medium

    SciTech Connect (OSTI)

    Oklop?i?, Antonija; Hirata, Christopher M., E-mail: oklopcic@astro.caltech.edu [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, MC 249-17, 1200 East California Boulevard, Pasadena, CA 91125 (United States)

    2013-12-20

    The intergalactic medium (IGM) prior to the epoch of reionization consists mostly of neutral hydrogen gas. Lyman-? (Ly?) photons produced by early stars resonantly scatter off hydrogen atoms, causing energy exchange between the radiation field and the gas. This interaction results in moderate heating of the gas due to the recoil of the atoms upon scattering, which is of great interest for future studies of the pre-reionization IGM in the H I 21 cm line. We investigate the effect of this Ly? heating in the IGM with linear density, temperature, and velocity perturbations. Perturbations smaller than the diffusion length of photons could be damped due to heat conduction by Ly? photons. The scale at which damping occurs and the strength of this effect depend on various properties of the gas, the flux of Ly? photons, and the way in which photon frequencies are redistributed upon scattering. To find the relevant length scale and the extent to which Ly? heating affects perturbations, we calculate the gas heating rates by numerically solving linearized Boltzmann equations in which scattering is treated by the Fokker-Planck approximation. We find that (1) perturbations add a small correction to the gas heating rate, and (2) the damping of temperature perturbations occurs at scales with comoving wavenumber k ? 10{sup 4} Mpc{sup –1}, which are much smaller than the Jeans scale and thus unlikely to substantially affect the observed 21 cm signal.

  19. Determination of temperature-dependent heat conductivity and thermal diffusivity of waste glass melter feed

    SciTech Connect (OSTI)

    Pokorny, Richard; Rice, Jarrett A.; Schweiger, Michael J.; Hrma, Pavel R.

    2013-06-01

    The cold cap is a layer of reacting glass batch floating on the surface of melt in an all-electric continuous glass melter. The heat needed for the conversion of the melter feed to molten glass must be transferred to and through the cold cap. Since the heat flux into the cold cap determines the rate of melting, the heat conductivity is a key property of the reacting feed. We designed an experimental setup consisting of a large cylindrical crucible with an assembly of thermocouples that monitors the evolution of the temperature field while the crucible is heated at a constant rate. Then we used two methods to calculate the heat conductivity and thermal diffusivity of the reacting feed: the approximation of the temperature field by polynomial functions and the finite-volume method coupled with least-squares analysis. Up to 680°C, the heat conductivity of the reacting melter feed was represented by a linear function of temperature.

  20. Cooling and Heating Season Impacts of Right-Sizing of Fixed- and Variable-Capacity Heat Pumps With Attic and Indoor Ductwork

    SciTech Connect (OSTI)

    Cummings, James; Withers, Charles; Kono, Jamie

    2015-06-01

    ?A new generation of central, ducted variable-capacity heat pump systems has come on the market, promising very high cooling and heating efficiency. They are controlled differently than standard fixed-capacity systems. Instead of cycling on at full capacity and then cycling off when the thermostat is satisfied, they vary their cooling and heating output over a wide range (approximately 40% - 118% of nominal full capacity), thus staying 'on' for 60% - 100% more hours per day compared to fixed -capacity systems. Experiments in this research examined the performance of 2-ton and 3-ton fixed- and variable-capacity systems and the impacts of system oversizing.

  1. Heat Pump Water Heaters | Department of Energy

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

    Heat Pump Water Heaters Heat Pump Water Heaters May 4, 2012 - 5:21pm Addthis A diagram of a heat pump water heater. A diagram of a heat pump water heater. What does this mean for...

  2. CONTROL SYSTEM FOR SOLAR HEATING and COOLING

    E-Print Network [OSTI]

    Dols, C.

    2010-01-01

    solar heated, boosted, or heated entirely in the auxiliary heater)for the solar-heated hot water. This heater can be seen insolar heating and cooling system, showing plumbing runs containing solenoid valves, auxiliary heater (

  3. Heating System Basics | Department of Energy

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

    using ducts. Boilers heat water, providing either hot water or steam for heating. Wood and Pellet Heating Provides a way to heat a building using biomass or waste sources....

  4. Performance Optimization of an Irreversible Heat Pump with Variable-temperature Heat Reservoirs 

    E-Print Network [OSTI]

    Huang, Y.; Sun, D.

    2006-01-01

    An irreversible cycle model of a heat pump operating between two variable-temperature heat reservoirs is established and used to analyze the performance of the heat pump affected by heat resistances, heat leakage and internal dissipation...

  5. Industrial Heat Recovery - 1982 

    E-Print Network [OSTI]

    Csathy, D.

    1982-01-01

    Industrial Research HTFS Re search Programme HTFS/1S/R19, "Dryout and Flow in Horizontal and Horizontal Hairpin Tubes". 6 l\\rnerican Boiler I1anufacturers Assoc iation, "Lexicon, Boiler & Auxiliary Eauinment", 7 G:t=iffith P., book of I:eat senow N... RECOVERY - 1982 by Denis Csathy, Deltak Corn,oration, !1inneapolis, 11N Two years ago I summarized 20 years of ex perience on Industrial Heat Recovery for the Energy-source Technology Conference and Exhibition held in New Orleans, Louisiana. l...

  6. Solar heated rotary kiln

    DOE Patents [OSTI]

    Shell, Pamela K. (Tracy, CA)

    1984-01-01

    A solar heated rotary kiln utilized for decomposition of materials, such as zinc sulfate. The rotary kiln has an open end and is enclosed in a sealed container having a window positioned for directing solar energy into the open end of the kiln. The material to be decomposed is directed through the container into the kiln by a feed tube. The container is also provided with an outlet for exhaust gases and an outlet for spent solids, and rests on a tiltable base. The window may be cooled and kept clear of debris by coolant gases.

  7. Heat transmission in Relativity

    E-Print Network [OSTI]

    A. Brotas; J. C. Fernandes

    2003-07-16

    The simultaneous study of deformation and heat transmission in a bar was ignored for about 150 years. The traditional Fourier equation just allows to study the evolution of temperature in a undeformable bar. The search for its relativistic variant is a task which must fail because in Relativity there are no undeformable bars. Rigid bodies, in the sense as rigid as possible, are deformables. In this work we show how to write in Relativity the system of equations necessary to study simultaneously deformation and temperature evolution along a rigid bar.

  8. ARM - Atmospheric Heat Budget

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.TheoryTuesday, August 10, 20102016Study (CHAPS)Archive CampaignListAtmospheric Heat

  9. Electron Heat Transport Measured

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submitKansas Nuclear ProfileMultiferroicAward |Electron CorrelationHeat Transport

  10. Residential heating oil price

    Gasoline and Diesel Fuel Update (EIA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet) Wyoming Dry Natural GasNaturalOctober 2015Administration (EIA) ‹heating

  11. Residential heating oil price

    Gasoline and Diesel Fuel Update (EIA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet) Wyoming Dry Natural GasNaturalOctober 2015Administration (EIA)heating oil

  12. Residential heating oil price

    Gasoline and Diesel Fuel Update (EIA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet) Wyoming Dry Natural GasNaturalOctober 2015Administration (EIA)heating

  13. North Village Ground Source Heat Pumps

    Broader source: Energy.gov [DOE]

    Overview: Installation of Ground Source Heat Pumps. Replacement of Aging Heat Pumps. Alignment with Furmans Sustainability Goals.

  14. Geothermal Heat Pumps are Scoring High Marks

    SciTech Connect (OSTI)

    2000-08-01

    Geothermal Energy Program Office of Geothermal and Wind Technologies Geothermal Heat Pumps are Scoring High Marks Geothermal heat pumps, one of the clean energy technology stars Geothermal heat pumps (GHPs) are one of the most cost-effective heating, cooling, and water heating systems available for both residential and commercial buildings. GHPs extract heat from the ground during the heating season and discharge waste heat to the ground during the cooling season. The U.S. Environmental Protecti

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

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

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

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

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

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

  17. Approximate Dynamic Programming for Networks: Fluid Models and Constraint Reduction

    E-Print Network [OSTI]

    Veatch, Michael H.

    of approximating functions for the differential cost. The first contribution of this paper is identifying new or piece-wise quadratic. Fluid cost has been used to initialize the value iteration algorithm [5Approximate Dynamic Programming for Networks: Fluid Models and Constraint Reduction Michael H

  18. USING THE LINEAR NOISE APPROXIMATION TO CHARACTERIZE MOLECULAR NOISE IN

    E-Print Network [OSTI]

    Ingalls, Brian

    USING THE LINEAR NOISE APPROXIMATION TO CHARACTERIZE MOLECULAR NOISE IN REACTION PATHWAYS Matthew Canada N2L 3G1 Abstract The Linear Noise Approximation offers an elegant analytic method to probe the effects of molecular noise on small-scale chemical reaction pathways by expanding the full chemical Master

  19. Motivation and Outline Hatree-Fock Theory and KLI Approximation

    E-Print Network [OSTI]

    Holzwarth, Natalie

    Motivation and Outline Hatree-Fock Theory and KLI Approximation Frozen core orbital approximation March 24, 2011 Xiao Xu, N. A. W. Holzwarth PAW + HF & KLI #12;Motivation and Outline Hatree-Fock Theory of HF and KLI Conclusion Outline 1 Motivation of this work: Why? orbital dependent functionals + PAW 2

  20. Transport approximations in partially diffusive media Guillaume Bal

    E-Print Network [OSTI]

    Bal, Guillaume

    Transport approximations in partially diffusive media Guillaume Bal Department of Applied Physics concerns the analysis of approximations of transport equations in diffusive media. Firstly, we consider a variational formulation for the first-order transport equation that has the correct diffusive behavior

  1. PROJECT REPORT USING NEURAL NETWORKS FOR APPROXIMATE RADIOSITY FORM FACTOR

    E-Print Network [OSTI]

    Anderson, Charles W.

    PROJECT REPORT USING NEURAL NETWORKS FOR APPROXIMATE RADIOSITY FORM FACTOR COMPUTATION Submitted, between each pair of objects within the scene. This project report explores the use of neural networks.3 Approximation with Neural Networks : : : : : : : : : : : : : : : : : : : : : : : 2 1.4 Outline of Project Report

  2. Tighter Bounds for Graph Steiner Tree Approximation Gabriel Robins

    E-Print Network [OSTI]

    Zelikovsky, Alexander

    and properties. In Section 3 we present our main algorithm, called k-LCA. The basic approximation result for k-LCA is proved in Section 4. In Sections 5 and 6 we prove an approximation ratio of the k-LCA algorithm in general graphs, and estimate the performance of the Iterated 1-Steiner and k-LCA heuristics in qu

  3. Tutorial, GECCO'05, Washington D.C. Fitness Approximation

    E-Print Network [OSTI]

    Yang, Shengxiang

    1 Tutorial, GECCO'05, Washington D.C. Fitness Approximation in Evolutionary Computation Yaochu Jin Honda Research Institute Europe Khaled Rasheed University of Georgia Tutorial, GECCO'05, Washington D expensive fitness evaluations Tutorial, GECCO'05, Washington D.C. Fitness Approximation Methods · Problem

  4. The Approximation of Nuclear Contaminant Transport in Porous Media

    E-Print Network [OSTI]

    Douglas Jr., Jim

    of a chain of radioactive waste products and to present the results of some typical simulationsThe Approximation of Nuclear Contaminant Transport in Porous Media Jim Douglas, Jr. #3; Chieh;ective and eÆcient numerical method for approximating the solution of equations that govern the transport

  5. Technical Note Variational free energy and the Laplace approximation

    E-Print Network [OSTI]

    Penny, Will

    Technical Note Variational free energy and the Laplace approximation Karl Friston,a, Jérémie the variational free energy under the Laplace approximation, with a focus on accounting for additional model complexity induced by increasing the number of model parameters. This is relevant when using the free energy

  6. Fast Vectorless Power Grid Verification Using an Approximate Inverse Technique

    E-Print Network [OSTI]

    Najm, Farid N.

    Fast Vectorless Power Grid Verification Using an Approximate Inverse Technique Nahi H. Abdul Ghani Department of ECE University of Toronto Toronto, Ontario, Canada f.najm@utoronto.ca ABSTRACT Power grid Aids General Terms Performance, Algorithms, Verification Keywords Power grid, voltage drop, approximate

  7. Fresnel approximations for acoustic fields of rectangularly symmetric sources

    E-Print Network [OSTI]

    Mast, T. Douglas

    Fresnel approximations for acoustic fields of rectangularly symmetric sources T. Douglas Masta for determining the acoustic fields of rectangularly symmetric, baffled, time-harmonic sources under the Fresnel. The expressions presented are generalized to three different Fresnel approximations that correspond, respectively

  8. Energy Content of Colliding Plane Waves using Approximate Noether Symmetries

    E-Print Network [OSTI]

    M. Sharif; Saira Waheed

    2011-09-19

    This paper is devoted to study the energy content of colliding plane waves using approximate Noether symmetries. For this purpose, we use approximate Lie symmetry method of Lagrangian for differential equations. We formulate the first-order perturbed Lagrangian for colliding plane electromagnetic and gravitational waves. It is shown that in both cases, there does not exist

  9. Approximate and Multipartite Quantum Correlation (Communication) Zhaohui Wei

    E-Print Network [OSTI]

    Jain, Rahul

    classical distributions or bipartite quantum states in the single-shot setting by Zhang (Proc. 3rd Innov that the cost to approximate a bipartite quantum state equals that to approximate its exact purifications, which the latter. We characterize the relationship between them by giving upper and lower bounds. 4

  10. Supplemental heating of deposition tooling shields

    DOE Patents [OSTI]

    Ohlhausen, James A. (Albuquerque, NM); Peebles, Diane E. (Albuquerque, NM); Hunter, John A. (Albuquerque, NM); Eckelmeyer, Kenneth H. (Albuquerque, NM)

    2000-01-01

    A method of reducing particle generation from the thin coating deposited on the internal surfaces of a deposition chamber which undergoes temperature variation greater than 100.degree. C. comprising maintaining the temperature variation of the internal surfaces low enough during the process cycle to keep thermal expansion stresses between the coating and the surfaces under 500 MPa. For titanium nitride deposited on stainless steel, this means keeping temperature variations under approximately 70.degree. C. in a chamber that may be heated to over 350.degree. C. during a typical processing operation. Preferably, a supplemental heater is mounted behind the upper shield and controlled by a temperature sensitive element which provides feedback control based on the temperature of the upper shield.

  11. IEICE TRANS. FUNDAMENTALS, VOL.E85 {A, NO.12 DECEMBER 2002 Approximate Maximum Likelihood Source Separation

    E-Print Network [OSTI]

    Choi, Seungjin

    IEICE TRANS. FUNDAMENTALS, VOL.E85 {A, NO.12 DECEMBER 2002 1 PAPER Approximate Maximum Likelihood (t)] T is generated by x(t) = As(t) + v(t); (1) where A 2 IR m#2;n (m #21; n) is called the mixing ma of Education of Korea for its #12;nancial support toward the Electrical and Computer Engineering Division

  12. Quantum Heat Bath

    E-Print Network [OSTI]

    Dorje C. Brody; Lane P. Hughston

    2014-11-17

    A model for a quantum heat bath is introduced. When the bath molecules have finitely many degrees of freedom, it is shown that the assumption that the molecules are weakly interacting is sufficient to enable one to derive the canonical distribution for the energy of a small system immersed in the bath. While the specific form of the bath temperature, for which we provide an explicit formula, depends on (i) spectral properties of the bath molecules, and (ii) the choice of probability measure on the state space of the bath, we are in all cases able to establish the existence of a strictly positive lower bound on the temperature of the bath. The results can be used to test the merits of different hypotheses for the equilibrium states of quantum systems. Two examples of physically plausible choices for the probability measure on the state space of a quantum heat bath are considered in detail, and the associated lower bounds on the temperature of the bath are worked out.

  13. Properties of the Boltzmann equation in the classical approximation

    SciTech Connect (OSTI)

    Tanji, Naoto; Epelbaum, Thomas; Gelis, Francois; Wu, Bin

    2014-12-30

    We study the Boltzmann equation with elastic point-like scalar interactions in two different versions of the the classical approximation. Although solving numerically the Boltzmann equation with the unapproximated collision term poses no problem, this allows one to study the effect of the ultraviolet cutoff in these approximations. This cutoff dependence in the classical approximations of the Boltzmann equation is closely related to the non-renormalizability of the classical statistical approximation of the underlying quantum field theory. The kinetic theory setup that we consider here allows one to study in a much simpler way the dependence on the ultraviolet cutoff, since one has also access to the non-approximated result for comparison.

  14. Properties of the Boltzmann equation in the classical approximation

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

    Epelbaum, Thomas; Gelis, François; Tanji, Naoto; Wu, Bin

    2014-12-30

    We examine the Boltzmann equation with elastic point-like scalar interactions in two different versions of the the classical approximation. Although solving numerically the Boltzmann equation with the unapproximated collision term poses no problem, this allows one to study the effect of the ultraviolet cutoff in these approximations. This cutoff dependence in the classical approximations of the Boltzmann equation is closely related to the non-renormalizability of the classical statistical approximation of the underlying quantum field theory. The kinetic theory setup that we consider here allows one to study in a much simpler way the dependence on the ultraviolet cutoff, since onemore »has also access to the non-approximated result for comparison.« less

  15. Residential Variable-Capacity Heat Pumps Sized to Heating Loads

    SciTech Connect (OSTI)

    Munk, Jeffrey D.; Jackson, Roderick K.; Odukomaiya, Adewale; Gehl, Anthony C.

    2014-01-01

    Variable capacity heat pumps are an emerging technology offering significant energy savings potential and improved efficiency. With conventional single-speed systems, it is important to appropriately size heat pumps for the cooling load as over-sizing would result in cycling and insufficient latent capacity required for humidity control. These appropriately sized systems are often under-sized for the heating load and require inefficient supplemental electric resistance heat to meet the heating demand. Variable capacity heat pumps address these shortcomings by providing an opportunity to intentionally size systems for the dominant heating season load without adverse effects of cycling or insufficient dehumidification in the cooling season. This intentionally-sized system could result in significant energy savings in the heating season, as the need for inefficient supplemental electric resistance heat is drastically reduced. This is a continuation of a study evaluating the energy consumption of variable capacity heat pumps installed in two unoccupied research homes in Farragut, a suburb of Knoxville, Tennessee. In this particular study, space conditioning systems are intentionally sized for the heating season loads to provide an opportunity to understand and evaluate the impact this would have on electric resistance heat use and dehumidification. The results and conclusions drawn through this research are valid and specific for portions of the Southeastern and Midwestern United States falling in the mixed-humid climate zone. While other regions in the U.S. do not experience this type of climate, this work provides a basis for, and can help understand the implications of other climate zones on residential space conditioning energy consumption. The data presented here will provide a framework for fine tuning residential building EnergyPlus models that are being developed.

  16. Heat pump having improved defrost system

    DOE Patents [OSTI]

    Chen, Fang C. (Knoxville, TN); Mei, Viung C. (Oak Ridge, TN); Murphy, Richard W. (Knoxville, TN)

    1998-01-01

    A heat pump system includes, in an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant: a compressor; an interior heat exchanger; an exterior heat exchanger; an accumulator; and means for heating the accumulator in order to defrost the exterior heat exchanger.

  17. Heat pump having improved defrost system

    DOE Patents [OSTI]

    Chen, F.C.; Mei, V.C.; Murphy, R.W.

    1998-12-08

    A heat pump system includes, in an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant: a compressor; an interior heat exchanger; an exterior heat exchanger; an accumulator; and means for heating the accumulator in order to defrost the exterior heat exchanger. 2 figs.

  18. Heat Pump Markets UK in Europe

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    Heat Pump Markets UK in Europe IEA Heat Pump Workshop 13. November 2012 Zoltan Karpathy #12;2 Excellence in Market Intelligence Agenda About BSRIA WMI UK in the European Heat Pump Market Heating BSRIA WMI UK in the European Heat Pump Market Heating Technologies in New and Existing Buildings Hybrid

  19. Heat extraction from salinity-gradient solar ponds using heat pipe heat exchangers

    SciTech Connect (OSTI)

    Tundee, Sura; Terdtoon, Pradit; Sakulchangsatjatai, Phrut; Singh, Randeep; Akbarzadeh, Aliakbar

    2010-09-15

    This paper presents the results of experimental and theoretical analysis on the heat extraction process from solar pond by using the heat pipe heat exchanger. In order to conduct research work, a small scale experimental solar pond with an area of 7.0 m{sup 2} and a depth of 1.5 m was built at Khon Kaen in North-Eastern Thailand (16 27'N102 E). Heat was successfully extracted from the lower convective zone (LCZ) of the solar pond by using a heat pipe heat exchanger made from 60 copper tubes with 21 mm inside diameter and 22 mm outside diameter. The length of the evaporator and condenser section was 800 mm and 200 mm respectively. R134a was used as the heat transfer fluid in the experiment. The theoretical model was formulated for the solar pond heat extraction on the basis of the energy conservation equations and by using the solar radiation data for the above location. Numerical methods were used to solve the modeling equations. In the analysis, the performance of heat exchanger is investigated by varying the velocity of inlet air used to extract heat from the condenser end of the heat pipe heat exchanger (HPHE). Air velocity was found to have a significant influence on the effectiveness of heat pipe heat exchanger. In the present investigation, there was an increase in effectiveness by 43% as the air velocity was decreased from 5 m/s to 1 m/s. The results obtained from the theoretical model showed good agreement with the experimental data. (author)

  20. Combined Heat and Power, Waste Heat, and District Energy

    Broader source: Energy.gov [DOE]

    Presentation—given at the Fall 2011 Federal Utility Partnership Working Group (FUPWG) meeting—covers combined heat and power (CHP) technologies and their applications.

  1. Heat pump with freeze-up prevention

    DOE Patents [OSTI]

    Ecker, Amir L. (Dallas, TX)

    1981-01-01

    What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid prevents freeze up of the second heat exchanger by keeping the temperature above the dew point; and, optionally, provides heat for efficient operation.

  2. Heat exchanger and related methods

    DOE Patents [OSTI]

    Turner, Terry D.; McKellar, Michael G.

    2015-12-22

    Heat exchangers include a housing having an inlet and an outlet and forming a portion of a transition chamber. A heating member may form another portion of the transition chamber. The heating member includes a first end having a first opening and a second end having a second opening larger than the first opening. Methods of conveying a fluid include supplying a first fluid into a transition chamber of a heat exchanger, supplying a second fluid into the transition chamber, and altering a state of a portion of the first fluid with the second fluid. Methods of sublimating solid particles include conveying a first fluid comprising a material in a solid state into a transition chamber, heating the material to a gaseous state by directing a second fluid through a heating member and mixing the first fluid and the second fluid.

  3. Micro thrust and heat generator

    DOE Patents [OSTI]

    Garcia, E.J.

    1998-11-17

    A micro thrust and heat generator have 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 micromachining techniques (LIGA). 30 figs.

  4. Development of Versatile Compressor Modeling using Approximation Techniques for Alternative Refrigerants Evaluation

    SciTech Connect (OSTI)

    Abdelaziz, Omar; Shrestha, Som S

    2014-01-01

    Refrigerants are the life-blood of vapor compression systems that are widely used in Heating, Ventilation, Air-Conditioning, and Refrigeration (HVAC&R) applications. The HVAC&R community is currently transitioning from main-stream refrigerants that have high Global Warming Potential (GWP) to alternative lower-GWP refrigerants. During this transition, it is important to account for the life cycle climate performance of alternative refrigerants since their performance will be different than that of higher-GWP refrigerants. This requires the evaluation of the system performance with the new refrigerants. Unfortunately, it is extremely difficult to predict the realistic performance of new alternative refrigerants without experimental validation. One of the main challenges in this regard is modeling the compressor performance with high fidelity due to the complex interaction of operating parameters, geometry, boundary conditions, and fluid properties. High fidelity compressor models are computationally expensive and require significant pre-processing to evaluate the performance of alternative refrigerants. This paper presents a new approach to modeling compressor performance when alternative refrigerants are used. The new modeling concept relies on using existing compressor performance to create an approximate model that captures the dependence of compressor performance on key operating parameters and fluid properties. The model can be built using a myriad of approximation techniques. This paper focuses on Kriging-based techniques to develop higher fidelity approximate compressor models. Baseline and at least one alternative refrigerant performance data are used to build the model. The model accuracy was evaluated by comparing the model results with compressor performance data using other refrigerants. Preliminary results show that the approximate model can predict the compressor mass flow rate and power consumption within 5%.

  5. Enhanced heat transfer using nanofluids

    DOE Patents [OSTI]

    Choi, Stephen U. S. (Lisle, IL); Eastman, Jeffrey A. (Naperville, IL)

    2001-01-01

    This invention is directed to a method of and apparatus for enhancing heat transfer in fluids such as deionized water. ethylene glycol, or oil by dispersing nanocrystalline particles of substances such as copper, copper oxide, aluminum oxide, or the like in the fluids. Nanocrystalline particles are produced and dispersed in the fluid by heating the substance to be dispersed in a vacuum while passing a thin film of the fluid near the heated substance. The fluid is cooled to control its vapor pressure.

  6. Heat sinking for printed circuitry

    DOE Patents [OSTI]

    Wilson, S.K.; Richardson, G.; Pinkerton, A.L.

    1984-09-11

    A flat pak or other solid-state device mounted on a printed circuit board directly over a hole extends therethrough so that the bottom of the pak or device extends beyond the bottom of the circuit board. A heat sink disposed beneath the circuit board contacts the bottom of the pak or device and provides direct heat sinking thereto. Pressure may be applied to the top of the pak or device to assure good mechanical and thermal contact with the heat sink.

  7. Spring 2014 Heat Transfer -2

    E-Print Network [OSTI]

    Virginia Tech

    Spring 2014 Heat Transfer - 2 A thin electronic chip is in the shape of a square wafer, b = 1 cm surface of the chip with a heat transfer coefficient of h = 100 W/m2 -K. Assume the chip has a uniform per side with a mass of m = 0.3 grams and specific heat of C = 103 J/kg-K. The chip is mounted

  8. Higher-degree linear approximations of nonlinear systems

    SciTech Connect (OSTI)

    Karahan, S.

    1989-01-01

    In this dissertation, the author develops a new method for obtaining higher degree linear approximations of nonlinear control systems. The standard approach in the analysis and synthesis of nonlinear systems is a first order approximation by a linear model. This is usually performed by obtaining a series expansion of the system at some nominal operating point and retaining only the first degree terms in the series. The accuracy of this approximation depends on how far the system moves away from the normal point, and on the relative magnitudes of the higher degree terms in the series expansion. The approximation is achieved by finding an appropriate nonlinear coordinate transformation-feedback pair to perform the higher degree linearization. With the proposed method, one can improve the accuracy of the approximation up to arbitrarily higher degrees, provided certain solvability conditions are satisfied. The Hunt-Su linearizability theorem makes these conditions precise. This approach is similar to Poincare's Normal Form Theorem in formulation, but different in its solution method. After some mathematical background the author derives a set of equations (called the Homological Equations). A solution to this system of linear equations is equivalent to the solution to the problem of approximate linearization. However, it is generally not possible to solve the system of equations exactly. He outlines a method for systematically finding approximate solutions to these equations using singular value decomposition, while minimizing an error with respect to some defined norm.

  9. Triple integrated heat pump system

    SciTech Connect (OSTI)

    Blackshaw, A.L.; Robinson, G.P. Jr.

    1987-03-03

    A heat pump system is described comprising: a first heat exchange means having first and second refrigerant connections; a second heat exchange means having first and second refrigerant connections; a third heat exchange means having first and second refrigerant connections; a refrigerant pressurizing device having a suction inlet and a high pressure outlet; a reversible refrigerant expansion means for expanding refrigerant from condenser to evaporator pressure connected between the second refrigerant connections on the first and second heat exchange means; an alternate refrigerant expansion means for expanding refrigerant from condenser to evaporator pressure connected to the second refrigerant connection on the third heat exchange means; check valve means connecting the alternate refrigerant expansion means to the common points between the reversible expansion means and each of the first and second heat exchange means so that refrigerant can flow from the alternate expansion means to the first and second heat exchange means but flow of refrigerant from the first and second heat exchange means is prevented; and control valve means.

  10. Heat distribution by natural convection

    SciTech Connect (OSTI)

    Balcomb, J.D.

    1985-01-01

    Natural convection can provide adequate heat distribution in many situtations that arise in buildings. This is appropriate, for example, in passive solar buildings where some rooms tend to be more strongly solar heated than others or to reduce the number of heating units required in a building. Natural airflow and heat transport through doorways and other internal building apertures is predictable and can be accounted for in the design. The nature of natural convection is described, and a design chart is presented appropriate to a simple, single-doorway situation. Natural convective loops that can occur in buildings are described and a few design guidelines are presented.

  11. Cyclotron subharmonics resonant (CSR) heating

    SciTech Connect (OSTI)

    Abe, H.

    1994-01-01

    The cyclotron subharmonics resonant (CSR) heating mechanism is studied using particle simulation codes with an emphasis on the relationship between CSR and the nonlinear Landua damping.

  12. Sodium heat engine electrical feedthrough

    DOE Patents [OSTI]

    Weber, Neill (Dearborn, MI)

    1985-01-01

    A thermoelectric generator device which converts heat energy to electrical energy. An alkali metal is used with a solid electrolyte and a hermetically sealed feedthrough structure.

  13. Heat flux solarimeter

    SciTech Connect (OSTI)

    Sartarelli, A.; Vera, S.; Cyrulies, E.; Echarri, R.; Samson, I.

    2010-12-15

    The solarimeter presented in this work is easy to assemble. It is calibrated and its performance is validated by means of Hottel's method. Finally, the curves obtained with this solarimeter are compared to the ones obtained with a commercial solarimeter. This device is based on the evaluation of the heat flow in a metal rod. In consequence, measurements are not affected by ambient temperature variations. On the other hand, there is a linear relationship between the temperatures measured at the rod ends and the incident radiation, as can be concluded both from the theory of its operation and the calibration lines obtained. The results obtained from the global irradiance measurements in the area of Los Polvorines (Buenos Aires Province), together with a preliminary evaluation of the solarimeter's response time, are presented in this work. (author)

  14. Holographic Heat Engines

    E-Print Network [OSTI]

    Clifford V. Johnson

    2014-09-04

    It is shown that in theories of gravity where the cosmological constant is considered a thermodynamic variable, it is natural to use black holes as heat engines. Two examples are presented in detail using AdS charged black holes as the working substance. We notice that for static black holes, the maximally efficient traditional Carnot engine is also a Stirling engine. The case of negative cosmological constant supplies a natural realization of these engines in terms of the field theory description of the fluids to which they are holographically dual. We first propose a precise picture of how the traditional thermodynamic dictionary of holography is extended when the cosmological constant is dynamical and then conjecture that the engine cycles can be performed by using renormalization group flow. We speculate about the existence of a natural dual field theory counterpart to the gravitational thermodynamic volume.

  15. Ceramic heat exchanger

    DOE Patents [OSTI]

    LaHaye, P.G.; Rahman, F.H.; Lebeau, T.P.; Severin, B.K.

    1998-06-16

    A tube containment system is disclosed. The tube containment system does not significantly reduce heat transfer through the tube wall. The contained tube is internally pressurized, and is formed from a ceramic material having high strength, high thermal conductivity, and good thermal shock resistance. The tube containment system includes at least one ceramic fiber braid material disposed about the internally pressurized tube. The material is disposed about the tube in a predetermined axial spacing arrangement. The ceramic fiber braid is present in an amount sufficient to contain the tube if the tube becomes fractured. The tube containment system can also include a plurality of ceramic ring-shaped structures, in contact with the outer surface of the tube, and positioned between the tube and the ceramic fiber braid material, and/or at least one transducer positioned within tube for reducing the internal volume and, therefore, the energy of any shrapnel resulting from a tube fracture. 6 figs.

  16. Ceramic heat exchanger

    DOE Patents [OSTI]

    LaHaye, Paul G. (Kennebunk, ME); Rahman, Faress H. (Portland, ME); Lebeau, Thomas P. E. (Portland, ME); Severin, Barbara K. (Biddeford, ME)

    1998-01-01

    A tube containment system. The tube containment system does not significantly reduce heat transfer through the tube wall. The contained tube is internally pressurized, and is formed from a ceramic material having high strength, high thermal conductivity, and good thermal shock resistance. The tube containment system includes at least one ceramic fiber braid material disposed about the internally pressurized tube. The material is disposed about the tube in a predetermined axial spacing arrangement. The ceramic fiber braid is present in an amount sufficient to contain the tube if the tube becomes fractured. The tube containment system can also include a plurality of ceramic ring-shaped structures, in contact with the outer surface of the tube, and positioned between the tube and the ceramic fiber braid material, and/or at least one transducer positioned within tube for reducing the internal volume and, therefore, the energy of any shrapnel resulting from a tube fracture.

  17. Waste Heat Recovery from High Temperature Off-Gases from Electric Arc Furnace

    SciTech Connect (OSTI)

    Nimbalkar, Sachin U [ORNL; Thekdi, Arvind [E3M Inc; Keiser, James R [ORNL; Storey, John Morse [ORNL

    2014-01-01

    This article presents a study and review of available waste heat in high temperature Electric Arc Furnace (EAF) off gases and heat recovery techniques/methods from these gases. It gives details of the quality and quantity of the sensible and chemical waste heat in typical EAF off gases, energy savings potential by recovering part of this heat, a comprehensive review of currently used waste heat recovery methods and potential for use of advanced designs to achieve a much higher level of heat recovery including scrap preheating, steam production and electric power generation. Based on our preliminary analysis, currently, for all electric arc furnaces used in the US steel industry, the energy savings potential is equivalent to approximately 31 trillion Btu per year or 32.7 peta Joules per year (approximately $182 million US dollars/year). This article describes the EAF off-gas enthalpy model developed at Oak Ridge National Laboratory (ORNL) to calculate available and recoverable heat energy for a given stream of exhaust gases coming out of one or multiple EAF furnaces. This Excel based model calculates sensible and chemical enthalpy of the EAF off-gases during tap to tap time accounting for variation in quantity and quality of off gases. The model can be used to estimate energy saved through scrap preheating and other possible uses such as steam generation and electric power generation using off gas waste heat. This article includes a review of the historical development of existing waste heat recovery methods, their operations, and advantages/limitations of these methods. This paper also describes a program to develop and test advanced concepts for scrap preheating, steam production and electricity generation through use of waste heat recovery from the chemical and sensible heat contained in the EAF off gases with addition of minimum amount of dilution or cooling air upstream of pollution control equipment such as bag houses.

  18. Improved approximate formulas for flux from cylindrical and rectangular sources

    SciTech Connect (OSTI)

    Wallace, O.J.; Bokharee, S.A.

    1993-03-01

    This report provides two new approximate formulas for the flux at detector points outside the radial and axial extensions of a homogeneous cylindrical source and improved approximate formulas for the flux at points opposite rectangular surface sources. These formulas extend the range of geometries for which analytic approximations may be used by shield design engineers to make rapid scoping studies and check more extensive calculations for reasonableness. These formulas can be used to support skeptical, independent evaluations and are also valuable teaching tools for introducing shield designers to complex shield analyses.

  19. Heat engine Device that transforms heat into work.

    E-Print Network [OSTI]

    Winokur, Michael

    adiabats Stirling engines The SES solar Stirling system isotherms the Stirling cycle 1 2 3 4 #12;6 Power less work than -Ws, because when the gas cooled its pressure also dropped. Stirling Engine (Beta1 Heat engine Device that transforms heat into work. It requires two energy reservoirs at different

  20. The local potential approximation in the background field formalism

    E-Print Network [OSTI]

    I. Hamzaan Bridle; Juergen A. Dietz; Tim R. Morris

    2014-03-20

    Working within the familiar local potential approximation, and concentrating on the example of a single scalar field in three dimensions, we show that the commonly used approximation method of identifying the total and background fields, leads to pathologies in the resulting fixed point structure and the associated spaces of eigenoperators. We then show how a consistent treatment of the background field through the corresponding modified shift Ward identity, can cure these pathologies, restoring universality of physical quantities with respect to the choice of dependence on the background field, even within the local potential approximation. Along the way we point out similarities to what has been previously found in the f(R) approximation in asymptotic safety for gravity.

  1. The WKB approximation for a linear potential and ceiling 

    E-Print Network [OSTI]

    Zapata, Todd Austin

    2009-05-15

    The physical problem this thesis deals with is a quantum system with linear potential driving a particle away from a ceiling (impenetrable barrier). This thesis will construct the WKB approximation of the quantum mechanical propagator...

  2. Mean Field Variational Approximations in Continuous-Time Markov Processes

    E-Print Network [OSTI]

    Friedman, Nir

    Mean Field Variational Approximations in Continuous-Time Markov Processes A thesis submitted Processes . . . . . . . . . . . . . . . . . . . 18 2.3 Continuous Time Markov Processes-component Representation - Continuous Time Bayesian Networks . 24 2.3.3 Inference in Continuous Time Markov Processes

  3. Numerical Approximations of Stochastic Optimal Stopping and Control Problems 

    E-Print Network [OSTI]

    Siska, David

    2007-01-01

    We study numerical approximations for the payoff function of the stochastic optimal stopping and control problem. It is known that the payoff function of the optimal stopping and control problem corresponds to the solution ...

  4. Approximate translation : media, narrative, and experience in urban design

    E-Print Network [OSTI]

    Crisman, Jonathan

    2013-01-01

    Approximate translation is developed as a design process through which the place-embedded history of an urban environment can be understood, allowing for better design and intervention in that urban environment. Generally, ...

  5. Tractability through approximation : a study of two discrete optimization problems

    E-Print Network [OSTI]

    Farahat, Amr, 1973-

    2004-01-01

    (cont.) algorithm, at one extreme, and complete enumeration, at the other extreme. We derive worst-case approximation guarantees on the solution produced by such an algorithm for matroids. We then define a continuous ...

  6. Queueing systems subject to random server failures: an approximation 

    E-Print Network [OSTI]

    Matis, Timothy

    1998-01-01

    research into finding exact or approximate methods that adjust key performance measures of a system to reflect server failures. Many of the methods that have been developed suffer either from a high degree of computational complexity or from tight...

  7. APPROXIMATING SPECTRAL INVARIANTS OF HARPER OPERATORS ON GRAPHS II

    E-Print Network [OSTI]

    Schick, Thomas

    APPROXIMATING SPECTRAL INVARIANTS OF HARPER OPERATORS ON GRAPHS II VARGHESE MATHAI, THOMAS SCHICK;2 VARGHESE MATHAI, THOMAS SCHICK, AND STUART YATES subset E+ of these edges in which each combinatorial edge

  8. Approximate dynamic programming with applications in multi-agent systems

    E-Print Network [OSTI]

    Valenti, Mario J. (Mario James), 1976-

    2007-01-01

    This thesis presents the development and implementation of approximate dynamic programming methods used to manage multi-agent systems. The purpose of this thesis is to develop an architectural framework and theoretical ...

  9. Approximate Description of the Mandelbrot Set. Thermodynamic Analogy

    E-Print Network [OSTI]

    O. B. Isaeva; S. P. Kuznetsov

    2005-04-29

    Analogy between an approximate version of Feigenbaum renormalization group analysis in complex domain and the phase transition theory of Yang-Lee (based on consideration of formally complexified thermodynamic values) is discussed. It is shown that the Julia sets of the renormalization transformation correspond to the approximation of Mandelbrot set of the original map. New aspects of analogy between the theory of dynamical systems and the phase transition theory are uncovered.

  10. Resonant-state expansion Born Approximation applied to Schrodinger's Equation

    E-Print Network [OSTI]

    Doost, M B

    2015-01-01

    The RSE Born Approximation is a new scattering formula in Physics, it allows the calculation of strong scattering via the Fourier transform of the scattering potential and Resonant-states. In this paper I apply the RSE Born Approximation to Schr\\"odinger's Equation. The resonant-states of the system can be calculated using the recently discovered RSE perturbation theory and normalised correctly to appear in spectral Green's functions via the flux volume normalisation.

  11. Mean field approximation for noisy delay coupled excitable neurons

    E-Print Network [OSTI]

    Nikola Buric; Dragana Rankovic; Kristina Todorovic; Nebojsa Vasovic

    2010-03-26

    Mean field approximation of a large collection of FitzHugh-Nagumo excitable neurons with noise and all-to-all coupling with explicit time-delays, modelled by $N\\gg 1$ stochastic delay-differential equations is derived. The resulting approximation contains only two deterministic delay-differential equations but provides excellent predictions concerning the stability and bifurcations of the averaged global variables of the exact large system.

  12. Pairing within the self-consistent quasiparticle random-phase approximation at finite temperature

    E-Print Network [OSTI]

    Dang, N Dinh

    2008-01-01

    An approach to pairing in finite nuclei at nonzero temperature is proposed, which incorporates the effects due to the quasiparticle-number fluctuation (QNF) around Bardeen-Cooper-Schrieffer (BCS) mean field and dynamic coupling to quasiparticle-pair vibrations within the self-consistent quasiparticle random-phase approximation (SCQRPA). The numerical calculations of pairing gap, total energy, and heat capacity were carried out within a doubly folded multilevel model as well as realistic nuclei $^{56}$Fe and $^{120}$Sn. The results obtained show that, under the effect of QNF, in the region of moderate and strong couplings, the sharp transition between the superconducting and normal phases is smoothed out, resulting in a thermal pairing gap, which does not collapse at the BCS critical temperature, but has a tail, which extends to high temperature. The dynamic coupling of quasiparticles to SCQRPA vibrations significantly improves the agreement with the results of exact calculations and those obtained within the ...

  13. Heat Pipe Solar Receiver Development Activities at Sandia National Laboratories

    SciTech Connect (OSTI)

    Adkins, D.R.; Andraka, C.E.; Moreno, J.B.; Moss, T.A.; Rawlinson, K.S.; Showalter, S.K.

    1999-01-08

    Over the past decade, Sandia National Laboratories has been involved in the development of receivers to transfer energy from the focus of a parabolic dish concentrator to the heater tubes of a Stirling engine. Through the isothermal evaporation and condensation of sodium. a heat-pipe receiver can efficiently transfer energy to an engine's working fluid and compensate for irregularities in the flux distribution that is delivered by the concentrator. The operation of the heat pipe is completely passive because the liquid sodium is distributed over the solar-heated surface by capillary pumping provided by a wick structure. Tests have shown that using a heat pipe can boost the system performance by twenty percent when compared to directly illuminating the engine heater tubes. Designing heat pipe solar receivers has presented several challenges. The relatively large area ({approximately}0.2 m{sup 2}) of the receiver surface makes it difficult to design a wick that can continuously provide liquid sodium to all regions of the heated surface. Selecting a wick structure with smaller pores will improve capillary pumping capabilities of the wick, but the small pores will restrict the flow of liquid and generate high pressure drops. Selecting a wick that is comprised of very tine filaments can increase the permeability of the wick and thereby reduce flow losses, however, the fine wick structure is more susceptible to corrosion and mechanical damage. This paper provides a comprehensive review of the issues encountered in the design of heat pipe solar receivers and solutions to problems that have arisen. Topics include: flow characterization in the receiver, the design of wick systems. the minimization of corrosion and dissolution of metals in sodium systems. and the prevention of mechanical failure in high porosity wick structures.

  14. Heat treating of manufactured components

    DOE Patents [OSTI]

    Ripley, Edward B. (Knoxville, TN)

    2012-05-22

    An apparatus for heat treating manufactured components using microwave energy and microwave susceptor material is disclosed. The system typically includes an insulating vessel placed within a microwave applicator chamber. A moderating material is positioned inside the insulating vessel so that a substantial portion of the exterior surface of each component for heat treating is in contact with the moderating material.

  15. Minimal universal quantum heat machine

    E-Print Network [OSTI]

    David Gelbwaser-Klimovsky; Robert Alicki; Gershon Kurizki

    2013-01-29

    In traditional thermodynamics the Carnot cycle yields the ideal performance bound of heat engines and refrigerators. We propose and analyze a minimal model of a heat machine that can play a similar role in quantum regimes. The minimal model consists of a single two-level system with periodically modulated energy splitting that is permanently, weakly, coupled to two spectrally-separated heat baths at different temperatures. The equation of motion allows to compute the stationary power and heat currents in the machine consistently with the second-law of thermodynamics. This dual-purpose machine can act as either an engine or a refrigerator (heat pump) depending on the modulation rate. In both modes of operation the maximal Carnot efficiency is reached at zero power. We study the conditions for finite-time optimal performance for several variants of the model. Possible realizations of the model are discussed.

  16. Intrinsically irreversible thermoacoustic heat engine

    SciTech Connect (OSTI)

    Wheatley, J.; Hofler, T.; Swift, G.W.; Migliori, A.

    1983-07-01

    Certain thermoacoustic effects are described which form the basis for a heat engine that is intrinsically irreversible in the sense that it requires thermal lags for its operation. After discussing several acoustical heating and cooling effects, including the behavior of a new structure called a ''thermoacoustic couple,'' we discuss structures that can be placed in acoustically resonant tubes to produce both substantial heat pumping effects and, for restricted heat inputs, large temperature differences. The results are analyzed quantitatively using a second-order thermoacoustic theory based on the work of Rott. The qualities of the acoustic engine are generalized to describe a class of intrinsically irreversible heat engines of which the present acoustic engine is a special case. Finally the results of analysis of several idealized intrinsically irreversible engines are presented. These suggest that the efficiency of such engines may be determined primarily by geometry or configuration rather than by temperature.

  17. Critical heat flux test apparatus

    DOE Patents [OSTI]

    Welsh, Robert E. (West Mifflin, PA); Doman, Marvin J. (McKeesport, PA); Wilson, Edward C. (West Mifflin, PA)

    1992-01-01

    An apparatus for testing, in situ, highly irradiated specimens at high temperature transients is provided. A specimen, which has a thermocouple device attached thereto, is manipulated into test position in a sealed quartz heating tube by a robot. An induction coil around a heating portion of the tube is powered by a radio frequency generator to heat the specimen. Sensors are connected to monitor the temperatures of the specimen and the induction coil. A quench chamber is located below the heating portion to permit rapid cooling of the specimen which is moved into this quench chamber once it is heated to a critical temperature. A vacuum pump is connected to the apparatus to collect any released fission gases which are analyzed at a remote location.

  18. Choosing the Summary Statistics and the Acceptance Rate in Approximate Bayesian

    E-Print Network [OSTI]

    Blum, Michael G. B.

    Choosing the Summary Statistics and the Acceptance Rate in Approximate Bayesian Computation or not. In this paper, I incorporate Approximate Bayesian Computation into a local Bayesian regression Computation, evidence approximation, empirical Bayes, Bayesian local regression 1 Introduction Approximate

  19. Modular heat exchanger

    DOE Patents [OSTI]

    Giardina, A.R.

    1981-03-03

    A shell and tube heat exchanger is described having a plurality of individually removable tube bundle modules. A lattice of structural steel forming rectangular openings therein is placed at each end of a cylindrical shell. Longitudinal structural members are placed in the shell between corners of the rectangular openings situated on opposite ends of the shell. Intermediate support members interconnect the longitudinal supports so as to increase the longitudinal supports rigidity. Rectangular parallelepiped tube bundle modules occupy the space defined by the longitudinal supports and end supports and each include a rectangular tube sheet situated on each end of a plurality of tubes extending there through, a plurality of rectangular tube supports located between the tube sheets, and a tube bundle module stiffening structure disposed about the bundle's periphery and being attached to the tube sheets and tube supports. The corners of each tube bundle module have longitudinal framework members which are mateable with and supported by the longitudinal support members. Intermediate support members constitute several lattices, each of which is situated in a plane between the end support members. The intermediate support members constituting the several lattices extend horizontally and vertically between longitudinal supports of adjacent tube module voids. An alternative embodiment for intermediate support members constitute a series of structural plates situated at the corners of the module voids and having recesses therein for receiving the respective longitudinal support members adjacent thereto, protrusions separating the recesses, and a plurality of struts situated between protrusions of adjacent structural plates. 12 figs.

  20. Modular heat exchanger

    DOE Patents [OSTI]

    Giardina, Angelo R. [Marple Township, Delaware County, PA

    1981-03-03

    A shell and tube heat exchanger having a plurality of individually removable tube bundle modules. A lattice of structural steel forming rectangular openings therein is placed at each end of a cylindrical shell. Longitudinal structural members are placed in the shell between corners of the rectangular openings situated on opposite ends of the shell. Intermediate support members interconnect the longitudinal supports so as to increase the longitudinal supports rigidity. Rectangular parallelpiped tube bundle moldules occupy the space defined by the longitudinal supports and end supports and each include a rectangular tube sheet situated on each end of a plurality of tubes extending therethrough, a plurality of rectangular tube supports located between the tube sheets, and a tube bundle module stiffening structure disposed about the bundle's periphery and being attached to the tube sheets and tube supports. The corners of each tube bundle module have longitudinal framework members which are mateable with and supported by the longitudinal support members. Intermediate support members constitute several lattice, each of which is situate d in a plane between the end support members. The intermediate support members constituting the several lattice extend horizontally and vertically between longitudinal supports of adjacent tube module voids. An alternative embodiment for intermediate support members constitute a series of structural plates situated at the corners of the module voids and having recesses therein for receiving the respective longitudinal support members adjacent thereto, protrusions separating the recesses, and a plurality of struts situated between protrusions of adjacent structural plates.

  1. Solid state heat engine

    SciTech Connect (OSTI)

    Cory, J.S.

    1981-12-15

    A compact solid state turbine heat engine can be devised by pairing the nitinol elements. Each element is characterized by being in thermal contact with at least one hot water and one cold water bath and mechanically coupled to at least one driven pulley and driver pulley. A second nitinol element is similarly configured with a driver pulley, driven pulley, hot and cold water bath. The driver pulley associated with the first nitinol element is mechanically coupled to the driven pulley of the second nitinol element. Similarly, the driver pulley of the second nitinol element is mechanically coupled to the driven pulley of the first nitinol element. The paired nitinol elements form a compound solid state turbine engine wherein each nitinol element lies in a single plane and wherein the engine may be combined with a plurality of such pairs for increased power output. The nitinol elements may also incorporate a snubber to limit the strain on the element and the engine may further incorporate a variable radius pulley to increase the efficiency of mechanical conversion.

  2. Characterization of local heat fluxes around ICRF antennas on JET

    SciTech Connect (OSTI)

    Campergue, A.-L.; Jacquet, P.; Monakhov, I.; Arnoux, G.; Brix, M.; Sirinelli, A.; Milanesio, D.; Colas, L.; Collaboration: JET-EFDA Contributors

    2014-02-12

    When using Ion Cyclotron Range of Frequency (ICRF) heating, enhanced power deposition on Plasma-Facing Components (PFCs) close to the antennas can occur. Experiments have recently been carried out on JET with the new ITER-Like-Wall (ILW) to characterize the heat fluxes on the protection of the JET ICRF antennas, using Infra-Red (IR) thermography measurement. The measured heat flux patterns along the poloidal limiters surrounding powered antennas were compared to predictions from a simple RF sheath rectification model. The RF electric field, parallel to the static magnetic field in front of the antenna, was evaluated using the TOPICA code, integrating a 3D flattened model of the JET A2 antennas. The poloidal density variation in front of the limiters was obtained from the mapping of the Li-beam or edge reflectometry measurements using the flux surface geometry provided by EFIT equilibrium reconstruction. In many cases, this simple model can well explain the position of the maximum heat flux on the different protection limiters and the heat-flux magnitude, confirming that the parallel RF electric field and the electron plasma density in front of the antenna are the main driving parameters for ICRF-induced local heat fluxes.

  3. Heat Supply Who What Where and -Why

    E-Print Network [OSTI]

    Columbia University

    ............................................... 7 1.5 The cost of heat .......................................................... 9 1.6 Combined heat and power plants (CHP) and other heat technologies ...................................10 2Heat Supply in Denmark Who What Where and - Why #12;Title: Heat Supply in Denmark - Who What Where

  4. Heat pipe with embedded wick structure

    DOE Patents [OSTI]

    Adkins, Douglas Ray (Albuquerque, NM); Shen, David S. (Albuquerque, NM); Tuck, Melanie R. (Albuquerque, NM); Palmer, David W. (Albuquerque, NM); Grafe, V. Gerald (Corrales, NM)

    1998-01-01

    A heat pipe has an embedded wick structure that maximizes capillary pumping capability. Heat from attached devices such as integrated circuits evaporates working fluid in the heat pipe. The vapor cools and condenses on a heat dissipation surface. The condensate collects in the wick structure, where capillary pumping returns the fluid to high heat areas.

  5. Heat pipe with embedded wick structure

    DOE Patents [OSTI]

    Adkins, Douglas Ray (Albuquerque, NM); Shen, David S. (Albuquerque, NM); Tuck, Melanie R. (Albuquerque, NM); Palmer, David W. (Albuquerque, NM); Grafe, V. Gerald (Corrales, NM)

    1999-01-01

    A heat pipe has an embedded wick structure that maximizes capillary pumping capability. Heat from attached devices such as integrated circuits evaporates working fluid in the heat pipe. The vapor cools and condenses on a heat dissipation surface. The condensate collects in the wick structure, where capillary pumping returns the fluid to high heat areas.

  6. Heat pipe with embedded wick structure

    DOE Patents [OSTI]

    Adkins, D.R.; Shen, D.S.; Tuck, M.R.; Palmer, D.W.; Grafe, V.G.

    1998-06-23

    A heat pipe has an embedded wick structure that maximizes capillary pumping capability. Heat from attached devices such as integrated circuits evaporates working fluid in the heat pipe. The vapor cools and condenses on a heat dissipation surface. The condensate collects in the wick structure, where capillary pumping returns the fluid to high heat areas. 7 figs.

  7. 4. Heat exchangers; Steam, steam processes

    E-Print Network [OSTI]

    Zevenhoven, Ron

    to transfer a certain heat rate Q (J/s = W) For a small section dx of the tube (with diameter D), the heat With average temperature difference = for the heat exchanger length, the heat rate can1/74 4. Heat exchangers; Steam, steam processes Ron Zevenhoven Åbo Akademi University Thermal

  8. Lithospheric Heat Flow and Dynamics! obvious signals!

    E-Print Network [OSTI]

    Sandwell, David T.

    · $d( ) heat = flow scalar subsidence rate constant X #12;heat flow related to subsidence rate (qb ! quLithospheric Heat Flow and Dynamics! ! · obvious signals! - heat flow, depth, and geoid height?! - are transform faults thermal contraction cracks?! #12;global heat budget! 7.5 TW 44 TW 25-15 TW 3-13 TW

  9. Combined Heat and Power Plant Steam Turbine

    E-Print Network [OSTI]

    Rose, Michael R.

    waste heat) Gas Turbine University Substation High Pressure Natural Gas Campus Electric Load SouthernCombined Heat and Power Plant Steam Turbine Steam Turbine Chiller Campus Heat Load Steam (recovered Generator Heat Recovery Alternative Uses: 1. Campus heating load 2. Steam turbine chiller to campus cooling

  10. Urban Sewage Delivery Heat Transfer System (2): Heat Transfer 

    E-Print Network [OSTI]

    Zhang, C.; Wu, R.; Li, X.; Li, G.; Zhuang, Z.; Sun, D.

    2006-01-01

    analysis of above flow resistance and energy cost, we know that the economy flux ratio of transfer heat-transfer means is between 0.54 and 0.85, namely sewage flux is smaller, and minC Cr min wwCVc?= . It is necessary to point out that though depending... efficiency of contranatant two pass thimble: ()213 1 11 21wwNn wz tt Cr tt 1n? ?? ?==?+ ? (1) Fig.1 Reverse-flow heat efficiency of TDHTS Contranatant single pass heat-transfer efficiency: ( ) ()1 1exp (1 ) 1exp (1)n Cr NTU Cr? = ?? ? ? Put...

  11. Testing of Stirling engine solar reflux heat-pipe receivers

    SciTech Connect (OSTI)

    Rawlinson, S.; Cordeiro, P.; Dudley, V.; Moss, T.

    1993-07-01

    Alkali metal heat-pipe receivers have been identified as a desirable interface to couple a Stirling-cycle engine with a parabolic dish solar concentrator. The reflux receiver provides power nearly isothermally to the engine heater heads while de-coupling the heater head design from the solar absorber surface design. The independent design of the receiver and engine heater head leads to high system efficiency. Heat pipe reflux receivers have been demonstrated at approximately 30 kW{sub t} power throughput by others. This size is suitable fm engine output powers up to 10 kW{sub e}. Several 25-kW{sub e}, Stirling-cycle engines exist, as well as designs for 75-kW{sub t} parabolic dish solar concentrators. The extension of heat pipe technology from 30 kW{sub t} to 75 kW{sub t} is not trivial. Heat pipe designs are pushed to their limits, and it is critical to understand the flux profiles expected from the dish, and the local performance of the wick structure. Sandia has developed instrumentation to monitor and control the operation of heat pipe reflux receivers to test their throughput limits, and analytical models to evaluate receiver designs. In the past 1.5 years, several heat pipe receivers have been tested on Sandia`s test bed concentrators (TBC`s) and 60-kW{sub t} solar furnace. A screen-wick heat pipe developed by Dynatherm was tested to 27.5 kW{sub t} throughput. A Cummins Power Generation (CPG)/Thermacore 30-kW{sub t} heat pipe was pushed to a throughput of 41 kW{sub t} to verify design models. A Sandia-design screen-wick and artery 75-kW{sub t} heat pipe and a CPG/Thermacore 75-kW{sub t} sintered-wick heat pipe were also limit tested on the TBC. This report reviews the design of these receivers, and compares test results with model predictions.

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

    DOE Patents [OSTI]

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

    1994-11-29

    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.

  13. Low-Cost Gas Heat Pump For Building Space Heating | Department...

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

    Low-Cost Gas Heat Pump For Building Space Heating Low-Cost Gas Heat Pump For Building Space Heating Credit: Stone Mountain Technologies Credit: Stone Mountain Technologies Lead...

  14. On exact and perturbation solutions to nonlinear equations for heat transfer models

    E-Print Network [OSTI]

    Francisco M. Fernández

    2009-11-03

    We analyze some exact and approximate solutions to nonlinear equations for heat transfer models. We prove that recent results derived from a method based on Lie algebras are either trivial or wrong. We test a simple analytical expression based on the hypervirial theorem and also discuss earlier perturbation results.

  15. Extended Heat Deposition in Hot Jupiters: Application to Ohmic Heating

    E-Print Network [OSTI]

    Ginzburg, Sivan

    2015-01-01

    Many giant exoplanets in close orbits have observed radii which exceed theoretical predictions. One suggested explanation for this discrepancy is heat deposited deep inside the atmospheres of these "hot Jupiters". Here, we study extended power sources which distribute heat from the photosphere to the deep interior of the planet. Our analytical treatment is a generalization of a previous analysis of localized "point sources". We model the deposition profile as a power law in the optical depth and find that planetary cooling and contraction halt when the internal luminosity (i.e. cooling rate) of the planet drops below the heat deposited in the planet's convective region. A slowdown in the evolutionary cooling prior to equilibrium is possible only for sources which do not extend to the planet's center. We estimate the Ohmic dissipation resulting from the interaction between the atmospheric winds and the planet's magnetic field, and apply our analytical model to Ohmically heated planets. Our model can account fo...

  16. Design of Heat Exchanger for Heat Recovery in CHP Systems 

    E-Print Network [OSTI]

    Kozman, T. A.; Kaur, B.; Lee, J.

    2009-01-01

    . Before the design process can begin, product specifications, such as steam or water pressures and temperatures, and equipment, such as absorption chillers and heat exchangers, need to be identified and defined. The Energy Engineering Laboratory...

  17. Active heat transfer enhancement in integrated fan heat sinks

    E-Print Network [OSTI]

    Staats, Wayne Lawrence

    2012-01-01

    Modern computer processors require significant cooling to achieve their full performance. The "efficiency" of heat sinks is also becoming more important: cooling of electronics consumes 1% of worldwide electricity use by ...

  18. Project Profile: Heat Transfer and Latent Heat Storage in Inorganic...

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

    energy storage capacity of a thermocline. The PCM-based TES uses the latent heat of fusion of inorganic salt mixtures for storing thermal energy. The concepts being applied by...

  19. Heat pipe device and heat pipe fabricating process

    SciTech Connect (OSTI)

    Busch, C.H.

    1982-08-10

    An energy saving liquid to liquid heat exchanger for a dishwasher or like device discharging hot waste water comprising a hot water tank for holding the waste water from the dishwasher and having inlet and outlet pipes, a cold water tank for holding the fresh water going to a water heater and having inlet and outlet pipes, the cold water tank disposed on top of the hot water tank, a bundle of heat pipes containing low boiling refrigerant disposed inside of the two tanks so as to extract heat from the hot water tank and give it up to the cold water tank, whereby the temperature of the fresh water leaving the heat exchanger is higher than its entering temperature.

  20. Heat Pump Cycle with Solution Circuit and Internal Heat Exchange 

    E-Print Network [OSTI]

    Radermacher, R.

    1986-01-01

    Vapor compression heat pumps which employ working fluid mixtures rather than pure substances offer significant advantages leading to larger temperature lifts at low pressure ratios or to completely new applications. The ...

  1. Heat Transfer Fluids for Solar Water Heating Systems | Department...

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

    a high boiling point. Viscosity and thermal capacity determine the amount of pumping energy required. A fluid with low viscosity and high specific heat is easier to pump, because...

  2. Variational principles with Padé approximants for tearing mode analysis

    SciTech Connect (OSTI)

    Cole, Andrew J.; Finn, John M.

    2014-03-15

    Tearing modes occur in several distinct physical regimes, and it is often important to compute the inner layer response for these modes with various effects. There is a need for an approximate and efficient method of solving the inner layer equations in all these regimes. In this paper, we introduce a method of solving the inner layer equations based on using a variational principle with Padé approximants. For all the regimes considered, the main layer equations to be solved are inhomogeneous, and Padé approximants give a convenient and efficient method of satisfying the correct asymptotic behavior at the edge of the layer. Results using this variational principle—Padé approximant method in three of these regimes is presented. These regimes are the constant-? resistive-inertial (RI) regime, the constant-? viscoresistive regime, and the non-constant-? inviscid tearing regime. The last regime includes the constant-? RI regime and the inertial regime. The results show that reasonable accuracy can be obtained very efficiently with Padé approximants having a small number of parameters.

  3. Carbon footprints of heating oil and LPG heating systems

    SciTech Connect (OSTI)

    Johnson, Eric P.

    2012-07-15

    For European homes without access to the natural gas grid, the main fuels-of-choice for heating are heating oil and LPG. How do the carbon footprints of these compare? Existing literature does not clearly answer this, so the current study was undertaken to fill this gap. Footprints were estimated in seven countries that are representative of the EU and constitute two-thirds of the EU-27 population: Belgium, France, Germany, Ireland, Italy, Poland and the UK. Novelties of the assessment were: systems were defined using the EcoBoiler model; well-to-tank data were updated according to most-recent research; and combustion emission factors were used that were derived from a survey conducted for this study. The key finding is that new residential heating systems fuelled by LPG are 20% lower carbon and 15% lower overall-environmental-impact than those fuelled by heating oil. An unexpected finding was that an LPG system's environmental impact is about the same as that of a bio heating oil system fuelled by 100% rapeseed methyl ester, Europe's predominant biofuel. Moreover, a 20/80 blend (by energy content) with conventional heating oil, a bio-heating-oil system generates a footprint about 15% higher than an LPG system's. The final finding is that fuel switching can pay off in carbon terms. If a new LPG heating system replaces an ageing oil-fired one for the final five years of its service life, the carbon footprint of the system's final five years is reduced by more than 50%.

  4. Heat pump assisted geothermal heating system for Felix Spa, Romania

    SciTech Connect (OSTI)

    Rosca, Marcel; Maghiar, Teodor

    1996-01-24

    The paper presents a pre-feasibility type study of a proposed heat pump assisted geothermal heating system for an average hotel in Felix Spa, Romania. After a brief presentation of the geothermal reservoir, the paper gives the methodology and the results of the technical and economical calculations. The technical and economical viability of the proposed system is discussed in detail in the final part of the paper.

  5. Heat exchanger with ceramic elements

    DOE Patents [OSTI]

    Corey, John A. (North Troy, NY)

    1986-01-01

    An annular heat exchanger assembly includes a plurality of low thermal growth ceramic heat exchange members with inlet and exit flow ports on distinct faces. A mounting member locates each ceramic member in a near-annular array and seals the flow ports on the distinct faces into the separate flow paths of the heat exchanger. The mounting member adjusts for the temperature gradient in the assembly and the different coefficients of thermal expansion of the members of the assembly during all operating temperatures.

  6. Heat exchanger using graphite foam

    DOE Patents [OSTI]

    Campagna, Michael Joseph; Callas, James John

    2012-09-25

    A heat exchanger is disclosed. The heat exchanger may have an inlet configured to receive a first fluid and an outlet configured to discharge the first fluid. The heat exchanger may further have at least one passageway configured to conduct the first fluid from the inlet to the outlet. The at least one passageway may be composed of a graphite foam and a layer of graphite material on the exterior of the graphite foam. The layer of graphite material may form at least a partial barrier between the first fluid and a second fluid external to the at least one passageway.

  7. Heat Waves, Global Warming, and Mitigation

    E-Print Network [OSTI]

    Carlson, Ann E.

    2008-01-01

    See U.S. ENVTL. PROT. AGENCY, HEAT ISLAND EFFECT, http:flJames A. Voogt, Urban Heat Islands: Hotter Cities (2004),213 Reducing the Urban Heat Island Effect A more structural

  8. Distributed Generation with Heat Recovery and Storage

    E-Print Network [OSTI]

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

    2008-01-01

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

  9. Heat Pump Water Heaters | Department of Energy

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

    A diagram of a heat pump water heater. A diagram of a heat pump water heater. What does this mean for me? Heat pump water heaters can be two to three times more energy efficient...

  10. Heat Distribution Systems | Department of Energy

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

    Forced-air systems use ducts that can also be used for central air conditioning and heat pump systems. Radiant heating systems also have unique heat distribution systems. That...

  11. Swimming Pool Heating | Department of Energy

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

    Swimming Pool Heating Swimming Pool Heating June 15, 2012 - 6:11pm Addthis You can reduce the cost of heating your swimming pool by installing a high-efficiency or solar heater,...

  12. Energy Saver 101: Water Heating Infographic

    Broader source: Energy.gov [DOE]

    Looking for ways to save money on water heating? Energy Saver 101: Water Heating infographic lays out evergything you need to know about water heating and shares ways to save energy and money.

  13. Design Considerations for Industrial Heat Recovery Systems 

    E-Print Network [OSTI]

    Bywaters, R. P.

    1979-01-01

    recovery design considerations as well as a summary of typical "waste heat" sources and application sites. A procedure for conducting industrial waste heat surveys is presented. Thermodynamic and heat transfer factors are discussed. Problems associated...

  14. Solar steam generation by heat localization

    E-Print Network [OSTI]

    Ghasemi, Hadi

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

  15. Development Requirements for Advanced Industrial Heat Pumps 

    E-Print Network [OSTI]

    Chappell, R. N.; Priebe, S. J.; Bliem, C. J.; Mills, J. I.

    1985-01-01

    DOE is attempting to advance the use of heat pumps to save energy in industrial processes. The approach has emphasized developing better heat pump technology and transferring that technology to the private sector. DOE requires that heat pump...

  16. Heat Pump Systems | Department of Energy

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

    generates hot and cold water rather than air, allowing it to be used with radiant floor heating systems in heating mode. Geothermal (ground-source or water-source) heat...

  17. CFD Simulation of Infiltration Heat Recovery

    E-Print Network [OSTI]

    Buchanan, C.R.

    2011-01-01

    So the infiltration heat recovery in most new houses wouldCFDSimulationof Infiltration Heat Recovery C.R.BuchananandSimulation of Infiltration Heat Recovery C.R. Buchanan and

  18. Waste Heat Utilization System Property Tax Exemption

    Broader source: Energy.gov [DOE]

    Waste heat utilization systems are facilities and equipment for the recovery of waste heat generated in the process of generating electricity and the use of such heat to generate additional elect...

  19. Solar heat storages in district heating Klaus Ellehauge Thomas Engberg Pedersen

    E-Print Network [OSTI]

    July 2007 . #12;#12;Solar heat storages in district heating networks July 2007 Klaus Ellehauge 97 22 11 tep@cowi.dk www.cowi.com #12;#12;Solar heat storages in district heating networks 5 References 45 Appendix 1 Danish companies 48 #12;6/50 Solar heat storages in district heating networks

  20. SYSTEM PERFORMANCE OF A STIRLING ENGINE POWERED HEAT ACTIVATED HEAT PUMP

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    AUG 1979 SYSTEM PERFORMANCE OF A STIRLING ENGINE POWERED HEAT ACTIVATED HEAT PUMP W. D. Richards W The development of the first prototype heat activated heat pump (HAHP) jointly sponsored by the Gas Research to supplement the heating capacity in addition to the heat pump effect would enable a HAHP system

  1. Value of electrical heat boilers and heat pumps for wind power integration

    E-Print Network [OSTI]

    Value of electrical heat boilers and heat pumps for wind power integration Peter Meibom Juha of using electrical heat boilers and heat pumps as wind power integration measures relieving the link\\ZRUGV wind power, integration, heat pumps, electric heat boilers ,QWURGXFWLRQ 3UREOHP RYHUYLHZ The Danish

  2. Modelling and simulation of a heat pump for simultaneous heating and cooling

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Modelling and simulation of a heat pump for simultaneous heating and cooling Paul Byrne1 *, Jacques-012-0089-0 #12;1. ABSTRACT The heat pump for simultaneous heating and cooling (HPS) carries out space heating to a standard reversible heat pump (HP). The air evaporator is defrosted by a two-phase thermosiphon without

  3. Fourth-post-Newtonian-exact approximation to General Relativity

    E-Print Network [OSTI]

    David Brizuela; Gerhard Schaefer

    2010-04-12

    An approximation to General Relativity is presented that agrees with the Einstein field equations up to and including the fourth post-Newtonian (PN) order. This approximation is formulated in a fully constrained scheme: all involved equations are explicitly elliptic except the wave equation that describes the two independent degrees of freedom of the gravitational field. The formalism covers naturally the conformal-flat-condition (CFC) approach by Isenberg, Wilson, and Mathews and the improved second PN-order exact approach CFC+. For stationary configurations, like Kerr black holes, agreement with General Relativity is achieved even through 5PN order. In addition, a particularly interesting 2PN-exact waveless approximation is analyzed in detail, which results from imposing more restrictive conditions. The proposed scheme can be considered as a further development on the waveless approach suggested by Schaefer and Gopakumar [Phys. Rev. D {\\bf 69}, 021501 (2004)].

  4. Promising Technology: Ground Source Heat Pumps

    Broader source: Energy.gov [DOE]

    Ground source heat pumps (GSHP) use the constant temperature of the Earth as the heat exchange medium instead of the outside air temperature. During the winter, a GSHP uses the ground as a heat source to provide heating, and during the summer, a GSHP uses the ground as a heat sink to provide cooling. Although more expensive than air-source heat pumps, GSHP’s are much more efficient, especially in cold temperatures.

  5. ,"Total District Heat Consumption (trillion Btu)",,,,,"District...

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

    Heat Consumption (trillion Btu)",,,,,"District Heat Energy Intensity (thousand Btusquare foot)" ,"Total ","Space Heating","Water Heating","Cook- ing","Other","Total ","Space...

  6. Waste Heat Management Options for Improving Industrial Process...

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

    Heat Management Options for Improving Industrial Process Heating Systems Waste Heat Management Options for Improving Industrial Process Heating Systems This presentation covers...

  7. Modeling, Estimation, and Control of Waste Heat Recovery Systems

    E-Print Network [OSTI]

    Luong, David

    2013-01-01

    System for Waste Heat Recovery. ” Journal of Heat Transfer,Rankine cycle for waste heat recovery. ” Energy, 29:1207–Strategy of Waste Heat Recovery Organic Rankine Cycles. ”

  8. Light weight and economical exhaust heat exchanger for waste...

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

    Light weight and economical exhaust heat exchanger for waste heat recovery using mixed radiant and convective heat transfer Light weight and economical exhaust heat exchanger for...

  9. Trigonometric Pade approximants for functions with regularly decreasing Fourier coefficients

    SciTech Connect (OSTI)

    Labych, Yuliya A; Starovoitov, Alexander P [Gomel State University, Gomel (Belarus)

    2009-08-31

    Sufficient conditions describing the regular decrease of the coefficients of a Fourier series f(x)=a{sub 0}/2 + {sigma} a{sub n} cos kx are found which ensure that the trigonometric Pade approximants {pi}{sup t}{sub n,m}(x;f) converge to the function f in the uniform norm at a rate which coincides asymptotically with the highest possible one. The results obtained are applied to problems dealing with finding sharp constants for rational approximations. Bibliography: 31 titles.

  10. L^p Bernstein Inequalities and Radial Basis Function Approximation 

    E-Print Network [OSTI]

    Ward, John P.

    2012-10-19

    are bounded in terms of certain measurements of the set X. The error of approximation will typically be given in terms of the ll distance hX = sup x2Rd inf 2X jjx jj2 ; which measures how far a point in Rd can be from X, and the stability of the ap... will typically be restricted to sets X for which hX is comparable to qX , and sets for which the mesh ratio X := hX=qX is bounded by a constant will be called quasi-uniform. In this paper, we will only consider approximation spaces SX( ) where X is quasi...

  11. On the approximation of crack shapes found during inservice inspection

    SciTech Connect (OSTI)

    Bhate, S.R.; Chawla, D.S.; Kushwaha, H.S. [Bhabha Atomic Research Centre, Bombay (India)] [and others

    1997-04-01

    This paper addresses the characterization of axial internal flaw found during inservice inspection of a pipe. J-integral distribution for various flaw shapes is obtained using line spring finite, element method. The peak J-value and its distribution across the crack is found to be characteristic feature of each shape. The triangular shape yields peak J-value away from the center, the point of depth. The elliptic approximation results in large overestimate of J-value for unsymmetric flaws. Triangular approximation is recommended for such flaws so that further service can be obtained from the component.

  12. Waste Heat Recovery from Refrigeration 

    E-Print Network [OSTI]

    Jackson, H. Z.

    1982-01-01

    heat recovery from refrigeration machines is a concept which has great potential for implementation in many businesses. If a parallel requirement for refrigeration and hot water exists, the installation of a system to provide hot water as a by...

  13. Low Level Heat Recovery Technology 

    E-Print Network [OSTI]

    O'Brien, W. J.

    1982-01-01

    With today's high fuel prices, energy conservation projects to utilize low level waste heat have become more attractive. Exxon Chemical Company Central Engineering has been developing guidelines and assessing the potential for application of low...

  14. Electrohydrodynamically enhanced condensation heat transfer 

    E-Print Network [OSTI]

    Wawzyniak, Markus

    1993-01-01

    In a condenser the thickness of the liquid condensate film covering the cooled surface constitutes a resistance to the heat transfer. By establishing a non uniform electric field in the vicinity of the condensation surface the extraction of liquid...

  15. Harvesting Electricity From Wasted Heat

    ScienceCinema (OSTI)

    Schwede, Jared

    2014-07-16

    Scientists as SLAC National Laboratory explain the concept, Photon Enhanced Thermionic Emission (PETE), and how this process can capture more energy from photovoltaic panels by harnessing heat energy from sunlight.

  16. Heat distribution by natural convection

    SciTech Connect (OSTI)

    Balcomb, J.D.

    1985-01-01

    Natural convection can provide adequate heat distribution in many situations that arise in buildings. This is appropriate, for example, in passive solar buildings where some rooms tend to be more strongly solar heated than others. Natural convection can also be used to reduce the number of auxiliary heating units required in a building. Natural airflow and heat transport through doorways and other internal building apertures are predictable and can be accounted for in the design. The nature of natural convection is described, and a design chart is presented appropriate to a simple, single-doorway situation. Experimental results are summarized based on the monitoring of 15 passive solar buildings which employ a wide variety of geometrical configurations including natural convective loops.

  17. Geothermal Heat Pump Grant Program

    Broader source: Energy.gov [DOE]

    The definition of geothermal heat pump property does not include swimming pools, hot tubs, or any other energy storage device that has a primary function other than storage. In addition, systems...

  18. Industrial Heat Pump Design Options 

    E-Print Network [OSTI]

    Gilbert, J. S.

    1985-01-01

    There are numerous industries that can incorporate heat pumps into their operations to save energy costs and payoff the investment in well under two years. Many of these industries can cut energy costs associated with evaporation by over 75...

  19. Heat Pumps - Theory and Applications 

    E-Print Network [OSTI]

    Altin, M.

    1982-01-01

    In this paper the thermodynamic viability of heat pumps is evaluated by potential work flux (exergy) analysis. A short description of the exergy (work potential) and other concepts such as 'lost work' needed for exergy analysis are given...

  20. Heat Recovery Steam Generator Simulation 

    E-Print Network [OSTI]

    Ganapathy, V.

    1993-01-01

    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...