Sample records for heating cycle shows

  1. Industrial Heat Recovery with Organic Rankine Cycles

    E-Print Network [OSTI]

    Hnat, J. G.; Patten, J. S.; Cutting, J. C.; Bartone, L. M.

    1982-01-01T23:59:59.000Z

    to examine a specific application of the use of an ORC heat recovery system and compare it to a stear), Rankine cycle heat recovery system. The particular application ~ssumed is heat recovery from diesel engine exhaust gas at a temPErature of 700F. Figure...,vaporized and superheated ina flue gas heat recovery su bsystem. he super heated fluid is expanded through a turbine for power p oduction, condensed in a water cooled condenser and return d to the vaporizer via feed pu mps. In the steam cycle, a port n of the Figure 1...

  2. Lessons Learned: Devolping Thermochemical Cycles for Solar Heat...

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

    Lessons Learned: Devolping Thermochemical Cycles for Solar Heat Storage Applications Lessons Learned: Devolping Thermochemical Cycles for Solar Heat Storage Applications This...

  3. Performance of an Organic Rankine Cycle Waste Heat Recovery System...

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

    Performance of an Organic Rankine Cycle Waste Heat Recovery System for Light Duty Diesel Engines Performance of an Organic Rankine Cycle Waste Heat Recovery System for Light Duty...

  4. Economizer refrigeration cycle space heating and cooling system and process

    DOE Patents [OSTI]

    Jardine, D.M.

    1983-03-22T23:59:59.000Z

    This invention relates to heating and cooling systems and more particularly to an improved system utilizing a Stirling Cycle engine heat pump in a refrigeration cycle. 18 figs.

  5. Economizer refrigeration cycle space heating and cooling system and process

    DOE Patents [OSTI]

    Jardine, Douglas M. (Colorado Springs, CO)

    1983-01-01T23:59:59.000Z

    This invention relates to heating and cooling systems and more particularly to an improved system utilizing a Stirling Cycle engine heat pump in a refrigeration cycle.

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

    E-Print Network [OSTI]

    Radermacher, R.

    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 main feature of such cycles...

  7. Quantum Thermodynamic Cycles and quantum heat engines

    E-Print Network [OSTI]

    H. T. Quan; Yu-xi Liu; C. P. Sun; Franco Nori

    2007-04-03T23:59:59.000Z

    In order to describe quantum heat engines, here we systematically study isothermal and isochoric processes for quantum thermodynamic cycles. Based on these results the quantum versions of both the Carnot heat engine and the Otto heat engine are defined without ambiguities. We also study the properties of quantum Carnot and Otto heat engines in comparison with their classical counterparts. Relations and mappings between these two quantum heat engines are also investigated by considering their respective quantum thermodynamic processes. In addition, we discuss the role of Maxwell's demon in quantum thermodynamic cycles. We find that there is no violation of the second law, even in the existence of such a demon, when the demon is included correctly as part of the working substance of the heat engine.

  8. Brayton Cycle Heat Pump for VOC Control

    E-Print Network [OSTI]

    Kovach, J. L.

    The first full size continuous operation Brayton Cycle Heat Pump (1)(2)(3) application for VOC recovery occurred in 1988. The mixed solvent recovery system was designed and supplied by NUCON for the 3M facility in Weatherford, OK (4). This first...

  9. Rankine cycle waste heat recovery system

    DOE Patents [OSTI]

    Ernst, Timothy C.; Nelson, Christopher R.

    2014-08-12T23:59:59.000Z

    This disclosure relates to a waste heat recovery (WHR) system and to a system and method for regulation of a fluid inventory in a condenser and a receiver of a Rankine cycle WHR system. Such regulation includes the ability to regulate the pressure in a WHR system to control cavitation and energy conversion.

  10. Control and optimal operation of simple heat pump cycles

    E-Print Network [OSTI]

    Skogestad, Sigurd

    Control and optimal operation of simple heat pump cycles Jørgen Bauck Jensen and Sigurd Skogestad in the opposite direction, the "heat pump", has recently become pop- ular. These two applications have also merged. The coefficients of performance for a heating cycle (heat pump) and a cooling cycle (refrigerator, A/C) are defined

  11. Sulfuric acid-sulfur heat storage cycle

    DOE Patents [OSTI]

    Norman, John H. (LaJolla, CA)

    1983-12-20T23:59:59.000Z

    A method of storing heat is provided utilizing a chemical cycle which interconverts sulfuric acid and sulfur. The method can be used to levelize the energy obtained from intermittent heat sources, such as solar collectors. Dilute sulfuric acid is concentrated by evaporation of water, and the concentrated sulfuric acid is boiled and decomposed using intense heat from the heat source, forming sulfur dioxide and oxygen. The sulfur dioxide is reacted with water in a disproportionation reaction yielding dilute sulfuric acid, which is recycled, and elemental sulfur. The sulfur has substantial potential chemical energy and represents the storage of a significant portion of the energy obtained from the heat source. The sulfur is burned whenever required to release the stored energy. A particularly advantageous use of the heat storage method is in conjunction with a solar-powered facility which uses the Bunsen reaction in a water-splitting process. The energy storage method is used to levelize the availability of solar energy while some of the sulfur dioxide produced in the heat storage reactions is converted to sulfuric acid in the Bunsen reaction.

  12. Organic rankine cycle waste heat applications

    DOE Patents [OSTI]

    Brasz, Joost J.; Biederman, Bruce P.

    2007-02-13T23:59:59.000Z

    A machine designed as a centrifugal compressor is applied as an organic rankine cycle turbine by operating the machine in reverse. In order to accommodate the higher pressures when operating as a turbine, a suitable refrigerant is chosen such that the pressures and temperatures are maintained within established limits. Such an adaptation of existing, relatively inexpensive equipment to an application that may be otherwise uneconomical, allows for the convenient and economical use of energy that would be otherwise lost by waste heat to the atmosphere.

  13. Sadi Carnot's Ingenious Reasoning of Ideal Heat Engine Reversible Cycles

    E-Print Network [OSTI]

    Kostic, Milivoje M.

    Sadi Carnot's Ingenious Reasoning of Ideal Heat Engine Reversible Cycles MILIVOJE M. KOSTIC and speculations flourished. Carnot's reasoning of reversible cycles is in many ways equal if not more significant was not noticed at his time, when his ingenious reasoning of ideal heat engine reversible cycles is not fully

  14. Thermodynamic analysis of the reverse Joule–Brayton cycle heat pump for domestic heating

    E-Print Network [OSTI]

    White, Alexander

    2009-03-20T23:59:59.000Z

    The paper presents an analysis of the effects of irreversibility on the performance of a reverse Joule–Brayton cycle heat pump for domestic heating applications. Both the simple and recuperated (regenerative) cycle are considered at a variety...

  15. A correlation of optimal heat rejection pressures in transcritical carbon dioxide cycles

    E-Print Network [OSTI]

    Zhao, Tianshou

    ®cance for the design and control of the transcritical carbon dioxide air- conditioning and heat pump systems 7 2000A correlation of optimal heat rejection pressures in transcritical carbon dioxide cycles S.M. Liaoa) of transcritical carbon dioxide air-conditioning cycles. The analysis shows that the COP of the transcritical

  16. The Seasonal Cycle of Atmospheric Heating and Temperature AARON DONOHOE

    E-Print Network [OSTI]

    Battisti, David

    The Seasonal Cycle of Atmospheric Heating and Temperature AARON DONOHOE Massachusetts Institute of Technology, Cambridge, Massachusetts DAVID S. BATTISTI Department of Atmospheric Sciences, University) ABSTRACT The seasonal cycle of the heating of the atmosphere is divided into a component due to direct

  17. Working on new gas turbine cycle for heat pump drive

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    Working on new gas turbine cycle for heat pump drive FILE COPY TAP By Irwin Stambler, Field Editor DO NOT 16 0 REMOVE 16 Small recuperated gas turbine engine, design rated at 13 hp and 27% efficiency of the cycle- as a heat pump drive for commercial installations. Company is testing prototype gas turbine

  18. Open cycle heat pump development for local resource use

    SciTech Connect (OSTI)

    Patch, K.D.; DiBella, F.A.; Glick, J.F.; Becker, F.E.

    1990-04-01T23:59:59.000Z

    District heating (DH) systems provide thermal energy to their customers in the form of hot water or steam. These systems can use one or more types of heat sources to meet the thermal load, including boilers, cogeneration systems, or low-grade heat sources in conjunction with a heat pump. Most large-scale heat pumps operate using the closed-cycle concept and usually use a chlorinated fluorocarbon (CFC) as the working fluid. An alternative to this approach is the quasi open-cycle heat pump, which was first studied in a Phase 1 report entitled Open-Cycle Heat Pump Development for Local Resource Use,'' DOE/CE/26563-5. The quasi open-cycle (QOC) heat pump actually uses the district heating transport medium as its working fluid. This document is the Final Report prepared as a part of Task 6 of Open-Cycle Heat Pump Development for Local Resource Use, Phase 2 District Heating Case Study Analysis. The objective of this study contract was to assess the application of the QOC heat pump in an actual case study. 43 figs., 11 tabs.

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

    E-Print Network [OSTI]

    Prasad, A.

    1980-01-01T23:59:59.000Z

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

  20. Stirling cycle engine and heat pump

    SciTech Connect (OSTI)

    Mitchell, M.P.

    1986-11-18T23:59:59.000Z

    A method is described of operating a hot gas engine comprising a cylinder having one end thereof connected to the other end thereof through at least two separate closed heat exchanger assemblies. Each comprises heated heat exchanger means and cooled heat exchanger means serially arranged, the hot end of each such closed heat exchanger assembly is attached to the same end of the cylinder. Each closed heat exchanger assembly is equipped with valve means at each end thereof, the cylinder accommodating a double-acting reciprocating piston means. The piston means cyclically displaces and is displaced by a volume of gas for each such closed heat exchanger assembly. The volumes of gas are alternately confined in and released from the closed heat exchanger assemblies by the valves.

  1. Optimization of a transcritical CO2 heat pump cycle for simultaneous cooling and heating applications

    E-Print Network [OSTI]

    Bahrami, Majid

    Optimization of a transcritical CO2 heat pump cycle for simultaneous cooling and heating of a transcritical carbon dioxide heat pump system are presented in this article. A computer code has been developed conditions. q 2004 Elsevier Ltd and IIR. All rights reserved. Keywords: Optimization; Heat pump; Carbon

  2. Control and optimal operation of simple heat pump cycles Jrgen B. Jensen and Sigurd Skogestad

    E-Print Network [OSTI]

    Skogestad, Sigurd

    Control and optimal operation of simple heat pump cycles Jørgen B. Jensen and Sigurd Skogestad cycle. Keywords: Operation, heat pump cycle, cyclic process, charge, self-optimizing control 1. The coefficients of performance for a heating cycle (heat pump) and a cooling cycle (re- frigerator, A

  3. High-Temperature Components for Rankine-Cycle-Based Waste Heat...

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

    High-Temperature Components for Rankine-Cycle-Based Waste Heat Recovery Systems on Combustion Engines High-Temperature Components for Rankine-Cycle-Based Waste Heat Recovery...

  4. Cascaded organic rankine cycles for waste heat utilization

    DOE Patents [OSTI]

    Radcliff, Thomas D. (Vernon, CT); Biederman, Bruce P. (West Hartford, CT); Brasz, Joost J. (Fayetteville, NY)

    2011-05-17T23:59:59.000Z

    A pair of organic Rankine cycle systems (20, 25) are combined and their respective organic working fluids are chosen such that the organic working fluid of the first organic Rankine cycle is condensed at a condensation temperature that is well above the boiling point of the organic working fluid of the second organic Rankine style system, and a single common heat exchanger (23) is used for both the condenser of the first organic Rankine cycle system and the evaporator of the second organic Rankine cycle system. A preferred organic working fluid of the first system is toluene and that of the second organic working fluid is R245fa.

  5. Degrees of freedom and optimal operation of simple heat pump cycles

    E-Print Network [OSTI]

    Skogestad, Sigurd

    Degrees of freedom and optimal operation of simple heat pump cycles Jørgen Bauck Jensen and Sigurd in the opposite direction, the "heat pump", has recently become pop- ular. These two applications have also merged of performance for a heating cycle (heat pump) and a cooling cycle (refrigerator, A/C) are defined as COPh = Qh

  6. Internal dissipation and heat leaks in quantum thermodynamic cycles

    E-Print Network [OSTI]

    Luis A. Correa; José P. Palao; Daniel Alonso

    2015-07-06T23:59:59.000Z

    The direction of the steady-state heat currents across a generic quantum system connected to multiple baths may be engineered so as to realize virtually any thermodynamic cycle. In spite of their versatility such continuous energy-conversion systems are generally unable to operate at maximum efficiency due to non-negligible sources of irreversible entropy production. In this paper we introduce a minimal model of irreversible absorption chiller. We identify and characterize the different mechanisms responsible for its irreversibility, namely heat leaks and internal dissipation, and gauge their relative impact in the overall cooling performance. We also propose reservoir engineering techniques to minimize these detrimental effects. Finally, by looking into a known three-qubit embodiment of the absorption cooling cycle, we illustrate how our simple model may help to pinpoint the different sources of irreversibility naturally arising in more complex practical heat devices.

  7. Design of organic Rankine cycles for conversion of waste heat in a polygeneration plant

    E-Print Network [OSTI]

    DiGenova, Kevin (Kevin J.)

    2011-01-01T23:59:59.000Z

    Organic Rankine cycles provide an alternative to traditional steam Rankine cycles for the conversion of low grade heat sources, where steam cycles are known to be less efficient and more expensive. This work examines organic ...

  8. Design Development Analyses in Support of a Heat pipe-Brayton Cycle Heat Exchanger

    SciTech Connect (OSTI)

    Steeve, Brian E. [NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States); Kapernick, Richard J. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2004-07-01T23:59:59.000Z

    One of the power systems under consideration for future space exploration applications, including nuclear electric propulsion or as a planetary surface power source, is a heat pipe-cooled reactor coupled to a Brayton cycle. In this system, power is transferred from the heat pipes to the Brayton gas via a heat exchanger attached to the heat pipes. This paper discusses the fluid, thermal and structural analyses that were performed in support of the design of the heat exchanger to be tested in the SAFE-100 experimental program at the Marshall Space Flight Center. An important consideration throughout the design development of the heat exchanger was its capability to be utilized for higher power and temperature applications. This paper also discusses this aspect of the design and presents designs for specific applications that are under consideration. (authors)

  9. Life cycle assessment of base-load heat sources for district heating system options

    SciTech Connect (OSTI)

    Ghafghazi, Saeed [University of British Columbia, Vancouver; Sowlati, T. [University of British Columbia, Vancouver; Sokhansanj, Shahabaddine [ORNL; Melin, Staffan [Delta Research Corporation

    2011-03-01T23:59:59.000Z

    Purpose There has been an increased interest in utilizing renewable energy sources in district heating systems. District heating systems are centralized systems that provide heat for residential and commercial buildings in a community. While various renewable and conventional energy sources can be used in such systems, many stakeholders are interested in choosing the feasible option with the least environmental impacts. This paper evaluates and compares environmental burdens of alternative energy source options for the base load of a district heating center in Vancouver, British Columbia (BC) using the life cycle assessment method. The considered energy sources include natural gas, wood pellet, sewer heat, and ground heat. Methods The life cycle stages considered in the LCA model cover all stages from fuel production, fuel transmission/transportation, construction, operation, and finally demolition of the district heating system. The impact categories were analyzed based on the IMPACT 2002+ method. Results and discussion On a life-cycle basis, the global warming effect of renewable energy options were at least 200 kgeqCO2 less than that of the natural gas option per MWh of heat produced by the base load system. It was concluded that less than 25% of the upstream global warming impact associated with the wood pellet energy source option was due to transportation activities and about 50% of that was resulted from wood pellet production processes. In comparison with other energy options, the wood pellets option has higher impacts on respiratory of inorganics, terrestrial ecotoxicity, acidification, and nutrification categories. Among renewable options, the global warming impact of heat pump options in the studied case in Vancouver, BC, were lower than the wood pellet option due to BC's low carbon electricity generation profile. Ozone layer depletion and mineral extraction were the highest for the heat pump options due to extensive construction required for these options. Conclusions Natural gas utilization as the primary heat source for district heat production implies environmental complications beyond just the global warming impacts. Diffusing renewable energy sources for generating the base load district heat would reduce human toxicity, ecosystem quality degradation, global warming, and resource depletion compared to the case of natural gas. Reducing fossil fuel dependency in various stages of wood pellet production can remarkably reduce the upstream global warming impact of using wood pellets for district heat generation.

  10. Efficient Heat Engines and Heat Pumps (10 credits) The aim of the module is to introduce the various ideal thermodynamic cycles that form

    E-Print Network [OSTI]

    Miall, Chris

    Efficient Heat Engines and Heat Pumps (10 credits) The aim of the module is to introduce and IC Engines performance. Syllabus Heat Engines and Heat Pumps · Second Law of Thermodynamics, Concept of heat engines and Heat Pumps · Ideal single phase heat engine cycles, Otto, Diesel, Gas Turbines Cycle

  11. Open cycle heat pump development: Phase II, District heating case study analysis: Progress report, October 1988--December 31, 1988

    SciTech Connect (OSTI)

    DiBella, F.; Becker, F.E.; Glick, J.

    1989-04-01T23:59:59.000Z

    A district heating system is proposed that uses low-level waste-energy sources, and a quasi open-cycle steam heat pump as a means of upgrading the energy in the form of hot water to use as a transport medium in the system. The use of a water-based, open-cycle heat pump appears to be extremely well suited in terms of its potential thermodynamic performance, cost, and environmental safety compared to more typical organic gased closed cycle systems. The Phase II case study provides a detailed analysis of a district heating system that utilizes the open cycle steam heat pump concept developed in Phase I. This quarterly report describes the energy audit performed on the heat source and heat sink.

  12. absorption cycle heat: Topics by E-print Network

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

    drive compressor heat pump; (3) absorption heat pump; (4) high temperature heat powered compressor heat pump; (5) reverse absorption heat... Erickson, D. C. 1983-01-01 First Page...

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

    E-Print Network [OSTI]

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

    1981-01-01T23:59:59.000Z

    An open Rankine-cycle heat pump is ideally suited for producing low-pressure industrial process steam. Because steam serves as both the heat pump motive fluid and process fluid, the system achieves a unique simplicity and versatility...

  14. Use of an open-cycle absorption system for heating and cooling

    SciTech Connect (OSTI)

    Schlepp, D. R.; Collier, R. K.

    1981-03-01T23:59:59.000Z

    Solar cooling for commercial applications using open-cycle absorption refrigeration systems has been investigated and found to be feasible. If an open-cycle absorption system can be operated as a chemical heat pump for winter heating operation, the system would offer year-round operation that could make the system economically viable for many regions of the US. An analysis of heating operation for the open-cycle system is presented using a computer program that simulates heat and mass transfer processes for any environmental condition. The open-cycle absorption refrigeration system can be operated as a chemical heat pump. Simulations for winter heating operation were run for five US cities, with solar COP's in the range of .06 to .16. At these levels, the OCAR system can provide full heating and cooling operation for office buildings in many southern US cities.

  15. Quantum Thermodynamic Cycles and Quantum Heat Engines (II)

    E-Print Network [OSTI]

    H. T. Quan

    2009-03-09T23:59:59.000Z

    We study the quantum mechanical generalization of force or pressure, and then we extend the classical thermodynamic isobaric process to quantum mechanical systems. Based on these efforts, we are able to study the quantum version of thermodynamic cycles that consist of quantum isobaric process, such as quantum Brayton cycle and quantum Diesel cycle. We also consider the implementation of quantum Brayton cycle and quantum Diesel cycle with some model systems, such as single particle in 1D box and single-mode radiation field in a cavity. These studies lay the microscopic (quantum mechanical) foundation for Szilard-Zurek single molecule engine.

  16. Thermodynamic Analysis of Combined Cycle District Heating System

    E-Print Network [OSTI]

    Suresh, S.; Gopalakrishnan, H.; Kosanovic, D.

    2011-01-01T23:59:59.000Z

    This paper presents a thermodynamic analysis of the University of Massachusetts' Combined Heat and Power (CHP) District Heating System. Energy and exergy analyses are performed based on the first and second laws of thermodynamics for power...

  17. EXPERIMENTAL AND THEORETICAL INVESTIGATIONS OF NEW POWER CYCLES AND ADVANCED FALLING FILM HEAT EXCHANGERS

    SciTech Connect (OSTI)

    Arsalan Razani; Kwang J. Kim

    2001-12-01T23:59:59.000Z

    The final report for the DOE/UNM grant number DE-FG26-98FT40148 discusses the accomplishments of both the theoretical analysis of advanced power cycles and experimental investigation of advanced falling film heat exchangers. This final report also includes the progress report for the third year (period of October 1, 2000 to September 30, 2001). Four new cycles were studied and two cycles were analyzed in detail based on the second law of thermodynamics. The first cycle uses a triple combined cycle, which consists of a topping cycle (Brayton/gas), an intermediate cycle (Rankine/steam), and a bottoming cycle (Rankine/ammonia). This cycle can produce high efficiency and reduces the irreversibility of the Heat Recovery Steam Generator (HRSC) of conventional combined power cycles. The effect of important system parameters on the irreversibility distribution of all components in the cycle under reasonable practical constraints was evaluated. The second cycle is a combined cycle, which consists of a topping cycle (Brayton/gas) and a bottoming cycle (Rankine/ammonia) with integrated compressor inlet air cooling. This innovative cycle can produce high power and efficiency. This cycle is also analyzed and optimized based on the second the second law to obtain the irreversibility distribution of all components in the cycle. The results of the studies have been published in peer reviewed journals and ASME conference proceeding. Experimental investigation of advanced falling film heat exchangers was conducted to find effective additives for steam condensation. Four additives have been selected and tested in a horizontal tube steam condensation facility. It has been observed that heat transfer additives have been shown to be an effective way to increase the efficiency of conventional tube bundle condenser heat exchangers. This increased condensation rate is due to the creation of a disturbance in the liquid condensate surround the film. The heat transfer through such a film has increased due to the onset of Maranogni convection as well as the population of ''dropwise-like'' condensation increased. The results have been published in peer reviewed journals.

  18. The Organic Rankine Cycle System, Its Application to Extract Energy From Low Temperature Waste Heat

    E-Print Network [OSTI]

    Sawyer, R. H.; Ichikawa, S.

    1980-01-01T23:59:59.000Z

    in a Rankine Cycle to extract The theoretical Rankine Cycle efficiency (~R) is energy from low temperature waste heat. By 1968, a defined as: 3.8 megawatt unit using R-11 refrigerant was placed in commercial operation in Japan (2) and currently ?ZR.... Figure 2 compares the theo The basic Organic Rankine Cycle may be described retical Rankine efficiency for several hydrocarbons, using the Pressure-Enthalpy Diagram of a typical fluorocarbons and water within the evaporating working fluid (R-11). (See...

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

    E-Print Network [OSTI]

    Pilon, Laurent

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

  20. Thermodynamic Analysis of Combined Cycle District Heating System 

    E-Print Network [OSTI]

    Suresh, S.; Gopalakrishnan, H.; Kosanovic, D.

    2011-01-01T23:59:59.000Z

    generation systems that include a 10 MW Solar combustion gas turbine, a 4-MW steam turbine, a 100,000 pph heat recovery steam generator (HRSG), three 125,000 pph package boilers, and auxiliary equipment. In the analysis, actual system data is used to assess...

  1. Open-Cycle Vapor Compression Heat Pump System

    E-Print Network [OSTI]

    Pasquinelli, D. M.; Becker, F. E.

    1983-01-01T23:59:59.000Z

    to the desired pressure level for process use. The compressor is driven by a gas turbine or gas engine prime mover. To enhance the system performance, the prime mover exhaust and/or cooling jacket heat is recovered to generate additional process steam or hot...

  2. Open cycle heat pump development for local resource use Phase II district heating case study analysis: Progress report, 1 January 1989--30 March 1989

    SciTech Connect (OSTI)

    DiBella, F.; Becker, F.E.; Glick, J.

    1989-05-01T23:59:59.000Z

    A district heating system is proposed that uses low-level waste- energy sources, and a quasi open-cycle steam heat pump as a means of upgrading the energy in the form of hot water to use as a transport medium in the system. the use of a water-based, open-cycle heat pump appears to be extremely well suited in terms of its potential thermodynamic performance, cost, and environmental safety compared to more typical organic gased closed cycle systems. The Phase II case study provides a detailed analysis of a district heating system that utilizes the open cycle steam heat pump concept developed in Phase I. This quarterly report describes the energy audit performed on the heat source and heat sink.

  3. A Novel Absorption Cycle for Combined Water Heating, Dehumidification, and Evaporative Cooling

    SciTech Connect (OSTI)

    CHUGH, Devesh [University of Florida, Gainesville; Gluesenkamp, Kyle R [ORNL; Abdelaziz, Omar [ORNL; Moghaddam, Saeed [University of Florida, Gainesville

    2014-01-01T23:59:59.000Z

    In this study, development of a novel system for combined water heating, dehumidification, and space evaporative cooling is discussed. Ambient water vapor is used as a working fluid in an open system. First, water vapor is absorbed from an air stream into an absorbent solution. The latent heat of absorption is transferred into the process water that cools the absorber. The solution is then regenerated in the desorber, where it is heated by a heating fluid. The water vapor generated in the desorber is condensed and its heat of phase change is transferred to the process water in the condenser. The condensed water can then be used in an evaporative cooling process to cool the dehumidified air exiting the absorber, or it can be drained if primarily dehumidification is desired. Essentially, this open absorption cycle collects space heat and transfers it to process water. This technology is enabled by a membrane-based absorption/desorption process in which the absorbent is constrained by hydrophobic vapor-permeable membranes. Constraining the absorbent film has enabled fabrication of the absorber and desorber in a plate-and-frame configuration. An air stream can flow against the membrane at high speed without entraining the absorbent, which is a challenge in conventional dehumidifiers. Furthermore, the absorption and desorption rates of an absorbent constrained by a membrane are greatly enhanced. Isfahani and Moghaddam (Int. J. Heat Mass Transfer, 2013) demonstrated absorption rates of up to 0.008 kg/m2s in a membrane-based absorber and Isfahani et al. (Int. J. Multiphase Flow, 2013) have reported a desorption rate of 0.01 kg/m2s in a membrane-based desorber. The membrane-based architecture also enables economical small-scale systems, novel cycle configurations, and high efficiencies. The absorber, solution heat exchanger, and desorber are fabricated on a single metal sheet. In addition to the open arrangement and membrane-based architecture, another novel feature of the cycle is recovery of the solution heat energy exiting the desorber by process water (a process-solution heat exchanger ) rather than the absorber exiting solution (the conventional solution heat exchanger ). This approach has enabled heating the process water from an inlet temperature of 15 C to 57 C (conforming to the DOE water heater test standard) and interfacing the process water with absorbent on the opposite side of a single metal sheet encompassing the absorber, process-solution heat exchanger, and desorber. The system under development has a 3.2 kW water heating capacity and a target thermal coefficient of performance (COP) of 1.6.

  4. Non-Hermitian heat engine with all-quantum-adiabatic-process cycle

    E-Print Network [OSTI]

    S. Lin; Z. Song

    2015-04-10T23:59:59.000Z

    A non-Hermitian system is expected to describe an open system which exchanges energy and particles with external reservoirs. Correspondingly, such an exchange can be adiabatic in the context of quantum mechanics. We investigate a non-Hermitian quantum heat engine (QHE) by a concrete simple two-level system, which is an S = 1/2 spin in a complex external magnetic field. The non- Hermitian PT -symmetric Hamiltonian, as a self-contained one, describes both working medium and reservoirs. A heat-engine cycle is composed of completely quantum adiabatic processes. The heat efficiency is obtained to be the same as that of Hermitian quantum Carnot cycle. The power output of this scheme can be arbitrary high, because the corresponding quantum adiabatic passages do not require a long time scale. A classical analogue of this scheme is also presented.

  5. Determination of the Transient Response Characteristics of the Air-Source Heat Pump During the Reverse Cycle Defrost 

    E-Print Network [OSTI]

    O'Neal, D. L.; Anand, N. K.; Peterson, K. T.; Schleising, S.

    1988-01-01T23:59:59.000Z

    The objectives of this research were to: (1) characterize the reverse cycle defrost of the air-to-air heat pump and (2) examine the effect of different expansion devices on the performance of the heat pump during the defrost cycle....

  6. Cooperative Efforts to Introduce New Environmental Control Technologies to Industry- A Case Study for Brayton Cycle Heat Pump Technology

    E-Print Network [OSTI]

    Enneking, J. C.

    COOPERATIVE EFFORTS TO INTRODUCE NEW ENVIRONMENTAL CONTROL TECHNOLOGIES TO INDUSTRY - A CASE STUDY FOR BRAYTON CYCLE HEAT PUMP TECHNOLOGY JOSEPH C. ENNEKING Vice President NUCON International, Inc. Columbus, ABSTRACT New environmental... CASE STUDY FOR BRAYTON CYCLE HEAT PUMP TECHNOLOGY JOSEPH C. ENNEKING Vice President NUCON International, Inc. Columbus, Ohio Figure 1 Reverse Brayton Cycle DOE FUNDED PROGRA}1 Solvents Turbine 4 3 Regenerator Solvents 5 2 1 Compressor Work in New...

  7. Theoretical thermodynamic analysis of a closed-cycle process for the conversion of heat into electrical energy

    E-Print Network [OSTI]

    Carati, Andrea

    Theoretical thermodynamic analysis of a closed-cycle process for the conversion of heat.g. by means of a solar concentrator), or can be the waste heat from an industrial pro- cess, or part of a co) Abstract We analyse a device aimed at the conversion of heat into electrical energy, based on a closed

  8. Improving the Control Performance of an Organic Rankine Cycle System for Waste Heat Recovery from a Heavy-Duty

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Improving the Control Performance of an Organic Rankine Cycle System for Waste Heat Recovery from, Antonio Sciarretta, Luc Voise, Pascal Dufour, Madiha Nadri Abstract-- In recent years, waste heat recovery waste heat from a heavy- duty diesel engine. For this system, a hierarchical and modular control

  9. Life Cycle cost Analysis of Waste Heat Operated Absorption Cooling Systems for Building HVAC Applications

    E-Print Network [OSTI]

    Saravanan, R.; Murugavel, V.

    2010-01-01T23:59:59.000Z

    effect from CO2 emission resulting from the combustion of fossil fuels in utility power plants and the use of chlorofluorocarbon refrigerants, which is currently thought to affect depletion of the ozone layer. The ban on fluorocarbon fluids has been...LIFE CYCLE COST ANALYSIS OF WASTE HEAT OPERATED ABSORPTION COOLING SYSTEMS FOR BUILDING HVAC APPLICATIONS V. Murugavel and R. Saravanan Refrigeration and Air conditioning Laboratory Department of Mechanical Engineering, Anna University...

  10. Potential for a cycling steam power plant with TES to supply district heating in Washington DC

    SciTech Connect (OSTI)

    Hobson, M.J.

    1984-02-01T23:59:59.000Z

    The Energy Office of the District of Columbia is planning the conversion of a 1500 TPD incinerator for district heating and the generation of electric power for sale to the local utility, PEPCO. This paper records a preliminary evaluation of whether hot water storage would be appropriate at the heat source plant to maximize power sales and improve the reliability of the district heat service. Hot water storage is being employed successfully at Herning, Denmark, in conjunction with a cogeneration plant heat source, and this concept is adapted to Washington D.C. area needs for heating and cooling service. Heat storage allows a 7% increase in power sales based on a simplified approach to daily load profiles and PEPCO's proposed avoided cost rates. Pressurized storage is uneconomic due to the high cost of containment, but atmospheric storage at 200F shows a simple payback of 5 years.

  11. Solar Thermochemical Fuels Production: Solar Fuels via Partial Redox Cycles with Heat Recovery

    SciTech Connect (OSTI)

    None

    2011-12-19T23:59:59.000Z

    HEATS Project: The University of Minnesota is developing a solar thermochemical reactor that will efficiently produce fuel from sunlight, using solar energy to produce heat to break chemical bonds. The University of Minnesota is envisioning producing the fuel by using partial redox cycles and ceria-based reactive materials. The team will achieve unprecedented solar-to-fuel conversion efficiencies of more than 10% (where current state-of-the-art efficiency is 1%) by combined efforts and innovations in material development, and reactor design with effective heat recovery mechanisms and demonstration. This new technology will allow for the effective use of vast domestic solar resources to produce precursors to synthetic fuels that could replace gasoline.

  12. Thermal cycling effect on the nanoparticle distribution and specific heat of a carbonate eutectic with alumina nanoparticles

    E-Print Network [OSTI]

    Shankar, Sandhya

    2011-08-08T23:59:59.000Z

    The objective of this research was to measure the effect of thermal cycling on the nanoparticle distribution and specific heat of a nanocomposite material consisting of a eutectic of lithium carbonate and potassium carbonate and 1% by mass alumina...

  13. Effect of Mixed Working Fluid Composition on Binary Cycle Condenser Heat Transfer Coefficients

    SciTech Connect (OSTI)

    Dan Wendt; Greg Mines

    2011-10-01T23:59:59.000Z

    Effect of Mixed Working Fluid Composition on Binary Cycle Condenser Heat Transfer Coefficients Dan Wendt, Greg Mines Idaho National Laboratory The use of mixed working fluids in binary power plants can provide significant increases in plant performance, provided the heat exchangers are designed to take advantage of these fluids non-isothermal phase changes. In the 1980's testing was conducted at DOE's Heat Cycle Research Facility (HCRF) where mixtures of different compositions were vaporized at supercritical pressures and then condensed. This testing had focused on using the data collected to verify that Heat Transfer Research Incorporated (HTRI) codes were suitable for the design of heat exchangers that could be used with mixtures. The HCRF data includes mixture compositions varying from 0% to 40% isopentane and condenser tube orientations of 15{sup o}, 60{sup o}, and 90{sup o} from horizontal. Testing was performed over a range of working fluid and cooling fluid conditions. Though the condenser used in this testing was water cooled, the working fluid condensation occurred on the tube-side of the heat exchanger. This tube-side condensation is analogous to that in an air-cooled condenser. Tube-side condensing heat transfer coefficient information gleaned from the HCRF testing is used in this study to assess the suitability of air-cooled condenser designs for use with mixtures. Results of an air-cooled binary plant process model performed with Aspen Plus indicate that that the optimal mixture composition (producing the maximum net power for the scenario considered) is within the range of compositions for which data exist. The HCRF data is used to assess the impact of composition, tube orientation, and process parameters on the condensing heat transfer coefficients. The sensitivity of the condensing coefficients to these factors is evaluated and the suitability of air-cooled condenser designs with mixtures is assessed. This paper summarizes the evaluation of the HCRF data and discusses the next steps in the project evaluation of air-cooled condenser designs that can take advantage of the performance gains possible with these fluids.

  14. SCALE RESISTANT HEAT EXCHANGER FOR LOW TEMPERATURE GEOTHERMAL BINARY CYCLE POWER PLANT

    SciTech Connect (OSTI)

    HAYS, LANCE G

    2014-11-18T23:59:59.000Z

    Phase 1 of the investigation of improvements to low temperature geothermal power systems was completed. The improvements considered were reduction of scaling in heat exchangers and a hermetic turbine generator (eliminating seals, seal system, gearbox, and lube oil system). A scaling test system with several experiments was designed and operated at Coso geothermal resource with brine having a high scaling potential. Several methods were investigated at the brine temperature of 235 ºF. One method, circulation of abradable balls through the brine passages, was found to substantially reduce scale deposits. The test heat exchanger was operated with brine outlet temperatures as low as 125 ºF, which enables increased heat input available to power conversion systems. For advanced low temperature cycles, such as the Variable Phase Cycle (VPC) or Kalina Cycle, the lower brine temperature will result in a 20-30% increase in power production from low temperature resources. A preliminary design of an abradable ball system (ABS) was done for the heat exchanger of the 1 megawatt VPC system at Coso resource. The ABS will be installed and demonstrated in Phase 2 of this project, increasing the power production above that possible with the present 175 ºF brine outlet limit. A hermetic turbine generator (TGH) was designed and manufacturing drawings produced. This unit will use the working fluid (R134a) to lubricate the bearings and cool the generator. The 200 kW turbine directly drives the generator, eliminating a gearbox and lube oil system. Elimination of external seals eliminates the potential of leakage of the refrigerant or hydrocarbon working fluids, resulting in environmental improvement. A similar design has been demonstrated by Energent in an ORC waste heat recovery system. The existing VPC power plant at Coso was modified to enable the “piggyback” demonstration of the TGH. The existing heat exchanger, pumps, and condenser will be operated to provide the required process conditions for the TGH demonstration. Operation of the TGH with and without the ABS system will demonstrate an increase in geothermal resource productivity for the VPC from 1 MW/(million lb) of brine to 1.75 MW/(million lb) of brine, a 75% increase.

  15. Consumer life-cycle cost impacts of energy-efficiency standards for residential-type central air conditioners and heat pumps

    SciTech Connect (OSTI)

    Rosenquist, Gregory; Chan, Peter; Lekov, Alex; McMahon, James; Van Buskirk, Robert

    2001-10-10T23:59:59.000Z

    In support of the federal government's efforts to raise the minimum energy-efficiency standards for residential-type central air conditioners and heat pumps, a consumer life-cycle cost (LCC) analysis was conducted to demonstrate the economic impacts on individual consumers from revisions to the standards. LCC is the consumer's cost of purchasing and installing an air conditioner or heat pump and operating the unit over its lifetime. The LCC analysis is conducted on a nationally representative sample of air conditioner and heat pump consumers resulting in a distribution of LCC impacts showing the percentage of consumers that are either benefiting or being burdened by increased standards. Relative to the existing minimum efficiency standard of 10 SEER, the results show that a majority of split system air conditioner and heat pump consumers will either benefit or be insignificantly impacted by increased efficiency standards of up to 13 SEER.

  16. original temperature and pressure, and all absorbed heat (or even more in non-ideal cycle) has to be removed out from the cyclic medium in order to complete the cycle, see

    E-Print Network [OSTI]

    Kostic, Milivoje M.

    it will not be possible to produce (cyclic) mechanical work from heat of fuel. In ideal reversible cycles, the exhaust), and vice versa. TABLE 1. Carnot cycle with ideal gas as working medium (see Figs. 2 & 7). Process Conditionoriginal temperature and pressure, and all absorbed heat (or even more in non-ideal cycle) has

  17. Extended Coronal Heating and Solar Wind Acceleration Over the Solar Cycle

    E-Print Network [OSTI]

    Cranmer, Steven R; Miralles, Mari Paz; van Ballegooijen, Adriaan A

    2010-01-01T23:59:59.000Z

    This paper reviews our growing understanding of the physics behind coronal heating (in open-field regions) and the acceleration of the solar wind. Many new insights have come from the last solar cycle's worth of observations and theoretical work. Measurements of the plasma properties in the extended corona, where the primary solar wind acceleration occurs, have been key to discriminating between competing theories. We describe how UVCS/SOHO measurements of coronal holes and streamers over the last 14 years have provided clues about the detailed kinetic processes that energize both fast and slow wind regions. We also present a brief survey of current ideas involving the coronal source regions of fast and slow wind streams, and how these change over the solar cycle. These source regions are discussed in the context of recent theoretical models (based on Alfven waves and MHD turbulence) that have begun to successfully predict both the heating and acceleration in fast and slow wind regions with essentially no fre...

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

    SciTech Connect (OSTI)

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

    2013-02-01T23:59:59.000Z

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

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

    SciTech Connect (OSTI)

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

    2013-07-01T23:59:59.000Z

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

  20. A Gas-Cooled-Reactor Closed-Brayton-Cycle Demonstration with Nuclear Heating

    SciTech Connect (OSTI)

    Lipinski, Ronald J.; Wright, Steven A.; Dorsey, Daniel J.; Williamson, Joshua [Advanced Nuclear Concepts Department, Sandia National Laboratories, P.O Box 5800, Albuquerque, NM 87185 (United States); Peters, Curtis D.; Brown, Nicholas [Advanced Nuclear Concepts Department, Sandia National Laboratories, P.O Box 5800, Albuquerque, NM 87185 (United States); Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, NM 87108 (United States); Jablonski, Jennifer [Advanced Nuclear Concepts Department, Sandia National Laboratories, P.O Box 5800, Albuquerque, NM 87185 (United States); Department of Education, University of New Mexico, Albuquerque, NM 87108 (United States)

    2005-02-06T23:59:59.000Z

    A gas-cooled reactor may be coupled directly to turbomachinery to form a closed-Brayton-cycle (CBC) system in which the CBC working fluid serves as the reactor coolant. Such a system has the potential to be a very simple and robust space-reactor power system. Gas-cooled reactors have been built and operated in the past, but very few have been coupled directly to the turbomachinery in this fashion. In this paper we describe the option for testing such a system with a small reactor and turbomachinery at Sandia National Laboratories. Sandia currently operates the Annular Core Research Reactor (ACRR) at steady-state powers up to 4 MW and has an adjacent facility with heavy shielding in which another reactor recently operated. Sandia also has a closed-Brayton-Cycle test bed with a converted commercial turbomachinery unit that is rated for up to 30 kWe of power. It is proposed to construct a small experimental gas-cooled reactor core and attach this via ducting to the CBC turbomachinery for cooling and electricity production. Calculations suggest that such a unit could produce about 20 kWe, which would be a good power level for initial surface power units on the Moon or Mars. The intent of this experiment is to demonstrate the stable start-up and operation of such a system. Of particular interest is the effect of a negative temperature power coefficient as the initially cold Brayton gas passes through the core during startup or power changes. Sandia's dynamic model for such a system would be compared with the performance data. This paper describes the neutronics, heat transfer, and cycle dynamics of this proposed system. Safety and radiation issues are presented. The views expressed in this document are those of the author and do not necessarily reflect agreement by the government.

  1. A gas-cooled-reactor closed-Brayton-cycle demonstration with nuclear heating.

    SciTech Connect (OSTI)

    Jablonski, Jennifer A.; Williamson, Joshua J.; Wright, Steven Alan; Dorsey, Daniel John; Brown, Nicholas; Peters, Curtis D.; Lipinski, Ronald J.

    2004-09-01T23:59:59.000Z

    A gas-cooled reactor may be coupled directly to turbomachinery to form a closed-Brayton-cycle (CBC) system in which the CBC working fluid serves as the reactor coolant. Such a system has the potential to be a very simple and robust space-reactor power system. Gas-cooled reactors have been built and operated in the past, but very few have been coupled directly to the turbomachinery in this fashion. In this paper we describe the option for testing such a system with a small reactor and turbomachinery at Sandia National Laboratories. Sandia currently operates the Annular Core Research Reactor (ACRR) at steady-state powers up to 4 MW and has an adjacent facility with heavy shielding in which another reactor recently operated. Sandia also has a closed-Brayton-Cycle test bed with a converted commercial turbomachinery unit that is rated for up to 30 kWe of power. It is proposed to construct a small experimental gas-cooled reactor core and attach this via ducting to the CBC turbomachinery for cooling and electricity production. Calculations suggest that such a unit could produce about 20 kWe, which would be a good power level for initial surface power units on the Moon or Mars. The intent of this experiment is to demonstrate the stable start-up and operation of such a system. Of particular interest is the effect of a negative temperature power coefficient as the initially cold Brayton gas passes through the core during startup or power changes. Sandia's dynamic model for such a system would be compared with the performance data. This paper describes the neutronics, heat transfer, and cycle dynamics of this proposed system. Safety and radiation issues are presented. The views expressed in this document are those of the author and do not necessarily reflect agreement by the government.

  2. A Tool for Life Cycle Climate Performance (LCCP) Based Design of Residential Air Source Heat Pumps

    SciTech Connect (OSTI)

    Beshr, Mohamed [University of Maryland, College Park; Aute, Vikrant [University of Maryland, College Park; Abdelaziz, Omar [ORNL; Fricke, Brian A [ORNL; Radermacher, Reinhard [University of Maryland, College Park

    2014-01-01T23:59:59.000Z

    A tool for the design of air source heat pumps (ASHP) based on their life cycle climate performance (LCCP) analysis is presented. The LCCP model includes direct and indirect emissions of the ASHP. The annual energy consumption of the ASHP is determined based on AHRI Standard 210/240. The tool can be used as an evaluation tool when the user inputs the required performance data based on the ASHP type selected. In addition, this tool has system design capability where the user inputs the design parameters of the different components of the heat pump and the tool runs the system simulation software to calculate the performance data. Additional features available in the tool include the capability to perform parametric analysis and sensitivity study on the system. The tool has 14 refrigerants, and 47 cities built-in with the option for the user to add more refrigerants, based on NIST REFPROP, and cities, using TMY-3 database. The underlying LCCP calculation framework is open source and can be easily customized for various applications. The tool can be used with any system simulation software, load calculation tool, and weather and emissions data type.

  3. Theoretical thermodynamic analysis of a closed-cycle process for the conversion of heat into electrical energy by means of a distiller and an electrochemical cell

    E-Print Network [OSTI]

    Carati, Andrea; Brogioli, Doriano

    2013-01-01T23:59:59.000Z

    We analyse a device aimed at the conversion of heat into electrical energy, based on a closed cycle in which a distiller generates two solutions at different concentrations, and an electrochemical cell consumes the concentration difference, converting it into electrical current. We first study an ideal model of such a process. We show that, if the device works at a single fixed pressure (i.e. with a "single effect"), then the efficiency of the conversion of heat into electrical power has an upper bound, given by the efficiency of a reversible Carnot engine operating between the boiling temperatures of the concentrated solution and of the pure solvent. When two heat reservoirs with a higher temperature difference are available, the overall efficiency can be incremented by employing an arrangement of multiple cells working at different pressures ("multiple effects"). We find that a given efficiency can be achieved with a reduced number of effects by using solutions with a high boiling point elevation.

  4. M . B a h r a m i ENSC 388 Experiment 2: Vapor Compression Refrigeration Cycle ENSC 388: Engineering Thermodynamics and Heat Transfer

    E-Print Network [OSTI]

    Bahrami, Majid

    1 M . B a h r a m i ENSC 388 Experiment 2: Vapor Compression Refrigeration Cycle ENSC 388: Engineering Thermodynamics and Heat Transfer Experiment 2: Vapor Compression Refrigeration Cycle Objective Determining the coefficient of performance of a vapour compression refrigeration cycle. Apparatus Figure 1

  5. Heat exchanger temperature response for duty-cycle transients in the NGNP/HTE.

    SciTech Connect (OSTI)

    Vilim, R. B.; Nuclear Engineering Division

    2009-03-12T23:59:59.000Z

    Control system studies were performed for the Next Generation Nuclear Plant (NGNP) interfaced to the High Temperature Electrolysis (HTE) plant. Temperature change and associated thermal stresses are important factors in determining plant lifetime. In the NGNP the design objective of a 40 year lifetime for the Intermediate Heat Exchanger (IHX) in particular is seen as a challenge. A control system was designed to minimize temperature changes in the IHX and more generally at all high-temperature locations in the plant for duty-cycle transients. In the NGNP this includes structures at the reactor outlet and at the inlet to the turbine. This problem was approached by identifying those high-level factors that determine temperature rates of change. First are the set of duty cycle transients over which the control engineer has little control but which none-the-less must be addressed. Second is the partitioning of the temperature response into a quasi-static component and a transient component. These two components are largely independent of each other and when addressed as such greater understanding of temperature change mechanisms and how to deal with them is achieved. Third is the manner in which energy and mass flow rates are managed. Generally one aims for a temperature distribution that minimizes spatial non-uniformity of thermal expansion in a component with time. This is can be achieved by maintaining a fixed spatial temperature distribution in a component during transients. A general rule of thumb for heat exchangers is to maintain flow rate proportional to thermal power. Additionally the product of instantaneous flow rate and heat capacity should be maintained the same on both sides of the heat exchanger. Fourth inherent mechanisms for stable behavior should not be compromised by active controllers that can introduce new feedback paths and potentially create under-damped response. Applications of these principles to the development of a plant control strategy for the reference NGNP/HTE plant can be found in the body of this report. The outcome is an integrated plant/control system design. The following conclusions are drawn from the analysis: (1) The plant load schedule can be managed to maintain near-constant hot side temperatures over the load range in both the nuclear and chemical plant. (2) The reactor open-loop response is inherently stable resulting mainly from a large Doppler temperature coefficient compared to the other reactivity temperature feedbacks. (3) The typical controller used to manage reactor power production to maintain reactor outlet temperature at a setpoint introduces a feedback path that tends to destabilize reactor power production in the NGNP. (4) A primary loop flow controller that forces primary flow to track PCU flow rate is effective in minimizing spatial temperature differentials within the IHX. (5) Inventory control in both the primary and PCU system during ramp load change transients is an effective means of maintaining high NGNP thermal efficiency while at reduced electric load. (6) Turbine bypass control is an effective means for responding to step changes in generator load when equipment capacity limitations prevent inventory control from being effective. (7) Turbine bypass control is effective in limiting PCU shaft over speed for the loss of generator load upset event. (8) The proposed control strategy is effective in limiting time variation of the differential spatial temperature distribution in the IHX during transients. Essentially the IHX can be made to behave in a manner where each point in the IHX experiences approximately the same temperature rate of change during a transient. (9) The stability of the closed-loop Brayton cycle was found to be sensitive to where one operates on the turbo-machine performance maps. There are competing interests: more stable operation means operating on the curves at points that reduce overall cycle efficiency. Future work should address in greater detail elements that came to light in the course of this work. Specifically: (1) A stability analysi

  6. An Analysis of Predicted vs. Monitored Space Heat Energy Use in 120 Homes : Residential Construction Demonstration Project Cycle II.

    SciTech Connect (OSTI)

    Douglass, John G.; Young, Marvin; Washington State Energy Office.

    1991-10-01T23:59:59.000Z

    The SUNDAY thermal simulation program was used to predict space heat energy consumption for 120 energy efficient homes. The predicted data were found to explain 43.8 percent of the variation in monitored space heat consumption. Using a paired Student's to test, no statistically significant difference could be found between mean predicted space heat and monitored space heat for the entire sample of homes. The homes were grouped into seven classes, sub-samples by total heat loss coefficient. An intermediate class (UA = 300--350 Btu/{degrees}F) was found to significantly over-predict space heat by 25 percent. The same class was over-predicted by 16 percent in the analogous Cycle 1 research, but the sample size was smaller and this was not found to be statistically significant. Several variables that were not directly included as inputs to the simulation were examined with an analysis of covariance model for their ability to improve the simulation's prediction of space heat. The variables having the greatest effect were conditioned floor area, heating system type, and foundation type. The model was able to increase the coefficient of determination from 0.438 to 0.670; a 54 percent increase. While the SUNDAY simulation program to aggregate is able to predict space heat consumption, it should be noted that there is a considerable amount of variation in both the monitored space heat consumption and the SUNDAY predictions. The ability of the program to accurately model an individual house will be constrained by both the quality of input variables and the range of occupant behavior. These constraints apply to any building model.

  7. An Analysis of Predicted vs. Monitored Space Heat Energy Use in 120 Homes :Residential Construction Demonstration Project Cycle II.

    SciTech Connect (OSTI)

    Douglass, John G.; Young, Marvin; Washington State Energy Office.

    1991-10-01T23:59:59.000Z

    The SUNDAY thermal simulation program was used to predict space heat energy consumption for 120 energy efficient homes. The predicted data were found to explain 43.8 percent of the variation in monitored space heat consumption. Using a paired Student`s to test, no statistically significant difference could be found between mean predicted space heat and monitored space heat for the entire sample of homes. The homes were grouped into seven classes, sub-samples by total heat loss coefficient. An intermediate class (UA = 300--350 Btu/{degrees}F) was found to significantly over-predict space heat by 25 percent. The same class was over-predicted by 16 percent in the analogous Cycle 1 research, but the sample size was smaller and this was not found to be statistically significant. Several variables that were not directly included as inputs to the simulation were examined with an analysis of covariance model for their ability to improve the simulation`s prediction of space heat. The variables having the greatest effect were conditioned floor area, heating system type, and foundation type. The model was able to increase the coefficient of determination from 0.438 to 0.670; a 54 percent increase. While the SUNDAY simulation program to aggregate is able to predict space heat consumption, it should be noted that there is a considerable amount of variation in both the monitored space heat consumption and the SUNDAY predictions. The ability of the program to accurately model an individual house will be constrained by both the quality of input variables and the range of occupant behavior. These constraints apply to any building model.

  8. Thermal cycling effect on the nanoparticle distribution and specific heat of a carbonate eutectic with alumina nanoparticles 

    E-Print Network [OSTI]

    Shankar, Sandhya

    2011-08-08T23:59:59.000Z

    in a separate cold tank, and then is circulated through the collector field, where it is heated again. Figure 3: Schematic of an active direct storage system (Solar Tres Power Plant) (3) The SEGS I plant included a direct two-tank storage system... Thomas Lalk Committee Member Michael Schuller Head of Department, Dennis O?Neal May 2011 Major Subject: Mechanical Engineering iii ABSTRACT Thermal Cycling Effects on the Nanoparticle Distribution...

  9. Waste Heat Energy Harvesting Using Olsen Cycle on PZN-5.5PT Single Crystals

    E-Print Network [OSTI]

    McKinley, Ian Meeker; Kandilian, Razmig; Pilon, Laurent

    2012-01-01T23:59:59.000Z

    High-ef?ciency direct conversion of heat to electricalreports on direct thermal to electrical energy conversion by

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

    DOE Patents [OSTI]

    Labinov, Solomon D.; Christian, Jeffrey E.

    2003-10-07T23:59:59.000Z

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

  11. The effects of expansion devices on the transient response characteristics of the air-source heat pump during the reverse cycle defrost 

    E-Print Network [OSTI]

    Peterson, Kurt T.

    1988-01-01T23:59:59.000Z

    THE EFFECTS OF EXPANSION DEVICES ON THE TRANSIENT RESPONSE CHARACTERISTICS OF THE AIR-SOURCE HEAT PUMP DURING THE REVERSE CYCLE DEFROST A Thesis by KURT T. PETERSON Submitted to the Graduate College of Texas A&M University in partial... fulfillment of the requirement for the degree of MASTER OF SCIENCE August 1988 Major Subject: Mechanical Engineering THE EFFECTS OF EXPANSION DEVICES ON THE TRANSIENT RESPONSE CHARACTERISTICS OF THE AIR-SOURCE HEAT PUMP DURING THE REVERSE CYCLE DEFROST...

  12. Diesel Cycle: Since we use a Closed System, the work and heat transfers are calculated from changes in internal energy u

    E-Print Network [OSTI]

    Diesel Cycle: Since we use a Closed System, the work and heat transfers are calculated from changes of Diesels (and therefore potential th) are likely to be much higher, because rather than worrying about pre-ignition, we are counting on self-ignition! 1 #12;On top of that, Diesel cycles have no throttling losses, so

  13. Feasibility Study of a Multi-Purpose Computer Program for Optimizing Heat Rates in Power Cycles

    E-Print Network [OSTI]

    Menuchin, Y.; Singh, K. P.; Hirota, N.

    1981-01-01T23:59:59.000Z

    A study of currently available commercial codes which evaluate the thermal performance of turbine cycles in power plants is presented. The analytical basis, capabilities, and possible applications of these codes are described. A survey of some user...

  14. Optimal Operation of closed cycles for heating and Jrgen B. Jensen Sigurd Skogestad

    E-Print Network [OSTI]

    Skogestad, Sigurd

    in cryogenic processes as air separation and liquefac- tion of natural gas (LNG process), more complex cycles in every home (Nagengast, 1976). Another well known system is the air-conditioner (A/C). In colder regions

  15. Generated using version 3.0 of the official AMS LATEX template The seasonal cycle of atmospheric heating and temperature1

    E-Print Network [OSTI]

    Battisti, David

    heating and temperature1 Aaron Donohoe Massachusetts Institute of Technology, Cambridge, Massachusetts 2 Institute of Technology, Dept. of Earth, Atmospheric and Planetary Sciences, Room Number 54-918, 77 to download Manuscript (non-LaTeX): seasonal_heating_1revision.pdf #12;ABSTRACT4 The seasonal cycle

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

    E-Print Network [OSTI]

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

    1981-01-01T23:59:59.000Z

    by an electric-motor-driven, multistage compressor train. This strategy permits the heat pump to accommodate upsets such as sudden changes in the waste stream flow and/or temperature, as well as fluctuation within the process stream....

  17. The Anderson Quin Cycle

    SciTech Connect (OSTI)

    Anderson, J.H.; Bilbow, W.M.

    1993-03-18T23:59:59.000Z

    The objective of this study was to make a more refined evaluation of the Anderson Quin Cycle based on most recent information on the performance of various elements that will be used in the Anderson Quin Cycle. My original estimate of the work plan for evaluating and optimizing the Anderson Quin Cycle called for 7000 man hours of work. Since this grant was limited to 2150 man hours, we could not expect to achieve all the objectives within the allotted period of work. However, the most relevant program objectives have been completed as reported here. The analysis generally confirms the results originally estimated in my paper on the subject. (Ref. 2) Further optimizations should show even higher efficiencies. The Anderson Quin Cycle (US Patent applied for) basically consists of 5 elements in the power cycle: A refrigeration system to cool and clean the inlet air before it enters the compressor that supplies air for the gas turbine; a gas turbine consisting of a compressor, combustor, and turbine; a steam boiler and steam turbine system using the heat from the exhaust gas out of the gas turbine; a vapor turbine cycle, which utilizes the condensed heat from the exhaust of the steam turbine and the exhaust gas heat leaving the steam boiler to operate a vapor turbine cycle which utilizes another fluid than water, in this case isobutane; and the fifth element consists of a gas cooler and heat pump system, which removes the heat from the exhaust gas to lower its temperature essentially to atmospheric temperature, and at the same time permits treatment of the exhaust gas to remove acid components such as sulfur dioxide and nitrogen oxides. Current industry accepted component characteristics were incorporated in the performance analysis of the overall cycle, ensuring accurate and meaningful operating predictions. The characteristics and performance of each of the elements are described. The thermal efficiency of the optimized calculated Anderson Quin Cycle is 62 percent.

  18. Brayton-cycle heat recovery-system characterization program. Subatmospheric-system test report

    SciTech Connect (OSTI)

    Burgmeier, L.; Leung, S.

    1981-07-31T23:59:59.000Z

    The turbine tests and results for the Brayton cycle subatmospheric system (SAS) are summarized. A scaled model turbine was operated in the same environment as that which a full-scale SAS machine would experience from the hot effluent flue gas from a glass container furnace. The objective of the testing was to evaluate the effects of a simulated furnace flue gas stream on the turbine nozzles and blades. The following specific areas were evaluated: erosion of the turbine nozzles and blades from the dust in the flue gas, hot corrosion from alkali metal salts in the dust and acid vapor (sulfur trioxide and hydrogen chloride) in the flue gas, and fouling and flow blockage due to deposition and/or condensation from the flue gas constituents.

  19. Final Report: Modifications and Optimization of the Organic Rankine Cycle to Improve the Recovery of Waste Heat

    SciTech Connect (OSTI)

    Donna Post Guillen; Jalal Zia

    2013-09-01T23:59:59.000Z

    This research and development (R&D) project exemplifies a shared public private commitment to advance the development of energy efficient industrial technologies that will reduce the U.S. dependence upon foreign oil, provide energy savings and reduce greenhouse gas emissions. The purpose of this project was to develop and demonstrate a Direct Evaporator for the Organic Rankine Cycle (ORC) for the conversion of waste heat from gas turbine exhaust to electricity. In conventional ORCs, the heat from the exhaust stream is transferred indirectly to a hydrocarbon based working fluid by means of an intermediate thermal oil loop. The Direct Evaporator accomplishes preheating, evaporation and superheating of the working fluid by a heat exchanger placed within the exhaust gas stream. Direct Evaporation is simpler and up to 15% less expensive than conventional ORCs, since the secondary oil loop and associated equipment can be eliminated. However, in the past, Direct Evaporation has been avoided due to technical challenges imposed by decomposition and flammability of the working fluid. The purpose of this project was to retire key risks and overcome the technical barriers to implementing an ORC with Direct Evaporation. R&D was conducted through a partnership between the Idaho National Laboratory (INL) and General Electric (GE) Global Research Center (GRC). The project consisted of four research tasks: (1) Detailed Design & Modeling of the ORC Direct Evaporator, (2) Design and Construction of Partial Prototype Direct Evaporator Test Facility, (3) Working Fluid Decomposition Chemical Analyses, and (4) Prototype Evaluation. Issues pertinent to the selection of an ORC working fluid, along with thermodynamic and design considerations of the direct evaporator, were identified. The FMEA (Failure modes and effects analysis) and HAZOP (Hazards and operability analysis) safety studies performed to mitigate risks are described, followed by a discussion of the flammability analysis of the direct evaporator. A testbed was constructed and the prototype demonstrated at the GE GRC Niskayuna facility.

  20. Preliminary studies on the heat exchanger option for S-CO{sub 2} power conversion cycle coupled to water cooled SMR

    SciTech Connect (OSTI)

    Ahn, Y.; Lee, J. [Dept. of Nuclear and Quantum Engineering, Korea Advanced Inst. of Science and Technology, 373-1 Guseong-dong Yuseong-gu, Daejeon, 305-701 (Korea, Republic of); Lee, J. I. [Dept. of Nuclear and Quantum Engineering, Korea Advanced Inst. of Science and Technology, 373-1 Guseong-dong Yuseong-gu, Daejeon, 305-701 (Korea, Republic of); Dept. of Nuclear Engineering, Khalifa Univ. of Science, Technology and Research (KUSTAR), P.O.Box 127788, Abu Dhabi (United Arab Emirates)

    2012-07-01T23:59:59.000Z

    For more than a half century, the steam Rankine cycle had been the major power conversion cycle for a nuclear power plant. However, as the interest on the next generation reactors grows, a variety of alternative power conversion systems have been studied. Among them, the S-CO{sub 2} cycle (Supercritical carbon dioxide Brayton cycle) is considered as a promising candidate due to several benefits such as 1) Relatively high thermal efficiency at relatively low turbine inlet temperature, 2) High efficiency with simple lay-out 3) Compactness of turbo-machineries. 4) Compactness of total cycle combined with PCHE (Printed Circuit Heat Exchanger). According to the conventional classification of heat exchangers (HE), there are three kind of HE, 1) Tubular HEs, 2) Plate-type HEs, 3) Extended surface HEs. So far, the researcher has mostly assumed PCHE type HE for the S-CO{sub 2} cycle due to its compactness with reasonably low pressure drop. However, PCHE is currently one of the most expensive components in the cycle, which can have a negative effect on the economics of the cycle. Therefore, an alternative for the HE should be seriously investigated. By comparing the operating condition (pressure and temperature) there are three kind of HE in the S-CO{sub 2} cycle, 1) IHX (Intermediate Heat exchanger) 2) Recuperator and 3) Pre-cooler. In each heat exchanger, hot side and cold side coolants are different, i.e. reactor coolant to S-CO{sub 2} (IHX), S-CO{sub 2} to S-CO{sub 2}(Recuperator), S-CO{sub 2} to water (Pre-cooler). By considering all the attributes mentioned above, all existing types of heat exchangers are compared to find a possible alternative to PCHE. The comparing factors are 1) Size(volume), 2) Cost. Plate fin type HEs are considered to be the most competitive heat exchanger regarding the size and the cost after some improvements on the design limit are made. (authors)

  1. Investigations of supercritical CO2 Rankine cycles for geothermal power plants

    SciTech Connect (OSTI)

    Sabau, Adrian S [ORNL; Yin, Hebi [ORNL; Qualls, A L [ORNL; McFarlane, Joanna [ORNL

    2011-01-01T23:59:59.000Z

    Supercritical CO2 Rankine cycles are investigated for geothermal power plants. The system of equations that describe the thermodynamic cycle is solved using a Newton-Rhapson method. This approach allows a high computational efficiency of the model when thermophysical properties of the working fluid depend strongly on the temperature and pressure. Numerical simulation results are presented for different cycle configurations in order to assess the influences of heat source temperature, waste heat rejection temperatures and internal heat exchanger design on cycle efficiency. The results show that thermodynamic cycle efficiencies above 10% can be attained with the supercritical brayton cycle while lower efficiencies can be attained with the transcritical CO2 Rankine cycle.

  2. Advanced heat pump for the recovery of volatile organic compounds. Phase 1, Conceptual design of an advanced Brayton cycle heat pump for the recovery of volatile organic compounds: Final report

    SciTech Connect (OSTI)

    Not Available

    1992-03-01T23:59:59.000Z

    Emissions of Volatile Organic Compounds (VOC) from stationary industrial and commercial sources represent a substantial portion of the total US VOC emissions. The ``Toxic-Release Inventory`` of The US Environmental Protection Agency estimates this to be at about 3 billion pounds per year (1987 estimates). The majority of these VOC emissions are from coating processes, cleaning processes, polymer production, fuel production and distribution, foam blowing,refrigerant production, and wood products production. The US Department of Energy`s (DOE) interest in the recovery of VOC stems from the energy embodied in the recovered solvents and the energy required to dispose of them in an environmentally acceptable manner. This Phase I report documents 3M`s work in close working relationship with its subcontractor Nuclear Consulting Services (Nucon) for the preliminary conceptual design of an advanced Brayton cycle heat pump for the recovery of VOC. Nucon designed Brayton cycle heat pump for the recovery of methyl ethyl ketone and toluene from coating operations at 3M Weatherford, OK, was used as a base line for the work under cooperative agreement between 3M and ODE. See appendix A and reference (4) by Kovach of Nucon. This cooperative agreement report evaluates and compares an advanced Brayton cycle heat pump for solvent recovery with other competing technologies for solvent recovery and reuse. This advanced Brayton cycle heat pump is simple (very few components), highly reliable (off the shelf components), energy efficient and economically priced.

  3. Procedure for Applying an Open-Cycle Heat Pump to An Existing Evaporator

    E-Print Network [OSTI]

    Wagner, J. R.; Brush, F. C.

    1984-01-01T23:59:59.000Z

    costs of evaporators are well known and have been implemented in many applications. The most basic method to reduce energy costs is to design an eva porator incorporating multiple effects, or stages, so that water vapor driven off in the first effect..., and flow ratings. MVC is of course applicable to other types of eva porators. Figure 2a shows a multiple effect fall ing film evaporator (FFE). Two effects are shown, but additional effects can be added simply by rep 1icat ing the second effect. New...

  4. Process Integration of Industrial Heat Pumps

    E-Print Network [OSTI]

    Priebe, S. J.; Chappell, R. N.

    PROCESS INTEGRATION OF INDUSTRIAL HEAT PUMPS* S. J. Priebe EG&G Idaho, Inc. Idaho Falls, Idaho ABSTRACT The integration of heat pumps into industrial processes shows potential for energy savings. Heat pumps must, however, be integrated... properly relative to the process pinch and the unit operations in the process. The shape of the grand composite curve, the type of heat ?pump drive, and the kind of heat pump cycle were examined to determine their effects on the placement of industrial...

  5. Pyroelectric waste heat energy harvesting using relaxor ferroelectric 8/65/35 PLZT and the Olsen cycle

    E-Print Network [OSTI]

    Pilon, Laurent

    Pyroelectric waste heat energy harvesting using relaxor ferroelectric 8/65/35 PLZT and the Olsen December 2011 Published 26 January 2012 Online at stacks.iop.org/SMS/21/025021 Abstract Waste heat can in the online journal) 1. Introduction Waste heat is rejected as a by-product of power, refrigeration or heat

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

    E-Print Network [OSTI]

    Kirol, L. D.

    1986-01-01T23:59:59.000Z

    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 working fluid is reactive...

  7. A Comparison of Supercritical Carbon Dioxide Power Cycle Configurations with an Emphasis on CSP Applications (Presentation)

    SciTech Connect (OSTI)

    Neises, T.; Turchi, C.

    2013-09-01T23:59:59.000Z

    Recent research suggests that an emerging power cycle technology using supercritical carbon dioxide (s-CO2) operated in a closed-loop Brayton cycle offers the potential of equivalent or higher cycle efficiency versus supercritical or superheated steam cycles at temperatures relevant for CSP applications. Preliminary design-point modeling suggests that s-CO2 cycle configurations can be devised that have similar overall efficiency but different temperature and/or pressure characteristics. This paper employs a more detailed heat exchanger model than previous work to compare the recompression and partial cooling cycles, two cycles with high design-point efficiencies, and illustrates the potential advantages of the latter. Integration of the cycles into CSP systems is studied, with a focus on sensible heat thermal storage and direct s-CO2 receivers. Results show the partial cooling cycle may offer a larger temperature difference across the primary heat exchanger, thereby potentially reducing heat exchanger cost and improving CSP receiver efficiency.

  8. Rankine and Brayton Cycle Cogeneration for Glass Melting 

    E-Print Network [OSTI]

    Hnat, J. G.; Patten, J. S.; Sheth, P. R.

    1981-01-01T23:59:59.000Z

    Rankine cycle, b) an organic Rankine cycle, c) an indirectly heated positive pressure Brayton cycle and d) a directly heated subatmospheric Brayton cycle. For the specified flue gas temperatures considered, the organic Rankine cycle produced the most...

  9. Supervision and control prototyping for an engine exhaust gas heat recovery system based on a steam Rankine cycle

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Supervision and control prototyping for an engine exhaust gas heat recovery system based on a steam of a practical supervi- sion and control system for a pilot Rankine steam process for exhaust gas heat recovery Rankine steam process for exhaust gas heat recovery from a spark-ignition (SI) engine, from a prototyping

  10. Open-cycle magnetohydrodynamic power plant based upon direct-contact closed-loop high-temperature heat exchanger

    DOE Patents [OSTI]

    Berry, Gregory F. (Naperville, IL); Minkov, Vladimir (Skokie, IL); Petrick, Michael (Joliet, IL)

    1988-01-01T23:59:59.000Z

    A magnetohydrodynamic (MHD) power generating system in which ionized combustion gases with slag and seed are discharged from an MHD combustor and pressurized high temperature inlet air is introduced into the combustor for supporting fuel combustion at high temperatures necessary to ionize the combustion gases, and including a heat exchanger in the form of a continuous loop with a circulating heat transfer liquid such as copper oxide. The heat exchanger has an upper horizontal channel for providing direct contact between the heat transfer liquid and the combustion gases to cool the gases and condense the slag which thereupon floats on the heat transfer liquid and can be removed from the channel, and a lower horizontal channel for providing direct contact between the heat transfer liquid and pressurized air for preheating the inlet air. The system further includes a seed separator downstream of the heat exchanger.

  11. Open-cycle magnetohydrodynamic power plant based upon direct-contact closed-loop high-temperature heat exchanger

    DOE Patents [OSTI]

    Berry, G.F.; Minkov, V.; Petrick, M.

    1981-11-02T23:59:59.000Z

    A magnetohydrodynamic (MHD) power generating system is described in which ionized combustion gases with slag and seed are discharged from an MHD combustor and pressurized high temperature inlet air is introduced into the combustor for supporting fuel combustion at high temperatures necessary to ionize the combustion gases, and including a heat exchanger in the form of a continuous loop with a circulating heat transfer liquid such as copper oxide. The heat exchanger has an upper horizontal channel for providing direct contact between the heat transfer liquid and the combustion gases to cool the gases and condense the slag which thereupon floats on the heat transfer liquid and can be removed from the channel, and a lower horizontal channel for providing direct contact between the heat transfer liquid and pressurized air for preheating the inlet air. The system further includes a seed separator downstream of the heat exchanger.

  12. Milestone Report #2: Direct Evaporator Leak and Flammability Analysis Modifications and Optimization of the Organic Rankine Cycle to Improve the Recovery of Waste Heat

    SciTech Connect (OSTI)

    Donna Post Guillen

    2013-09-01T23:59:59.000Z

    The direct evaporator is a simplified heat exchange system for an Organic Rankine Cycle (ORC) that generates electricity from a gas turbine exhaust stream. Typically, the heat of the exhaust stream is transferred indirectly to the ORC by means of an intermediate thermal oil loop. In this project, the goal is to design a direct evaporator where the working fluid is evaporated in the exhaust gas heat exchanger. By eliminating one of the heat exchangers and the intermediate oil loop, the overall ORC system cost can be reduced by approximately 15%. However, placing a heat exchanger operating with a flammable hydrocarbon working fluid directly in the hot exhaust gas stream presents potential safety risks. The purpose of the analyses presented in this report is to assess the flammability of the selected working fluid in the hot exhaust gas stream stemming from a potential leak in the evaporator. Ignition delay time for cyclopentane at temperatures and pressure corresponding to direct evaporator operation was obtained for several equivalence ratios. Results of a computational fluid dynamic analysis of a pinhole leak scenario are given.

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

    SciTech Connect (OSTI)

    Piyush Sabharwall; Mike Patterson; Vivek Utgikar; Fred Gunnerson

    2008-09-01T23:59:59.000Z

    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.

  14. Stirling-cycle refrigerator

    SciTech Connect (OSTI)

    Nakamura, K.

    1985-06-11T23:59:59.000Z

    A Stirling-cycle refrigerator comprises a plurality of Stirling-cycle refrigerator units each having a displacer defining an expansion chamber, a piston defining a compression chamber, and a circuit including a heater and a cooler and interconnecting the expansion chamber and the compression chamber, and a heat exchanger shared by the circuits and disposed between the coolers and the heaters for effecting heat exchange between working gases in the circuits. The heat exchanger may comprise a countercurrent heat exchanger, and the Stirling-cycle refrigerator units are operated in cycles which are 180/sup 0/ out of phase with each other.

  15. The effect of alternate defrost strategies on the reverse-cycle defrost of an air-source heat pump

    E-Print Network [OSTI]

    Schliesing, John Steven

    1988-01-01T23:59:59.000Z

    with and understanding of my questions and ideas. Thanks also to my family and friends for their support and help svhile I svorked on this project. Finally, I would like to acknowledge the American Society oi' Heating, Refrigerating, and Air-Conditioning Engineers... . . 21 Psychrometric Room Temperature Control Characteristics during a Frosting, 'Defrosting Test 3. 3 4. 3 4. 10 4. 11 Refrigerant Circuit Arrangement of the Outdoor Coil Heat Pump System Schematic Refrigerant Line Temperature Probe . Indoor...

  16. Determination of the Transient Response Characteristics of the Air-Source Heat Pump During the Reverse Cycle Defrost

    E-Print Network [OSTI]

    O'Neal, D. L.; Anand, N. K.; Peterson, K. T.; Schleising, S.

    1988-01-01T23:59:59.000Z

    .1 Description of Test Points 3.9 Fi?. 3.4 Heat Pump System Schematic 3.10 Fig. 3.5 Refrigerant Line Temperature Probe 3.11 for leak testing, equipment replacement, and system break- down. The valves proved to be extremely useful because when a specific section... Laboratory Department of Mechanical Engineering Texas A&M University ESL-TR-88/06-04 GLOSSARY OF TERMS AMCA Air Movement and Control Association ARI Air Conditioning and Refrigeration Institute ASHRAE American Society of Heating, Refrigerating and Air...

  17. Quantum Otto cycle efficiency on coupled qudits

    E-Print Network [OSTI]

    E. A. Ivanchenko

    2014-12-22T23:59:59.000Z

    Properties of the coupled particles with spin 3/2 (quartits) in a constant magnetic field, as a working substance in the quantum Otto cycle of the heat engine, are considered. It is shown that this system as a converter of heat energy in work (i) shows the efficiency 1 at the negative absolute temperatures of heat baths, (ii) at the temperatures of the opposite sign the efficiency approaches to 1, (iii) at the positive temperatures of heat baths antiferromagnetic interaction raises efficiency threefold in comparison with uncoupled particles.

  18. The Anderson Quin Cycle. Final report

    SciTech Connect (OSTI)

    Anderson, J.H.; Bilbow, W.M.

    1993-03-18T23:59:59.000Z

    The objective of this study was to make a more refined evaluation of the Anderson Quin Cycle based on most recent information on the performance of various elements that will be used in the Anderson Quin Cycle. My original estimate of the work plan for evaluating and optimizing the Anderson Quin Cycle called for 7000 man hours of work. Since this grant was limited to 2150 man hours, we could not expect to achieve all the objectives within the allotted period of work. However, the most relevant program objectives have been completed as reported here. The analysis generally confirms the results originally estimated in my paper on the subject. (Ref. 2) Further optimizations should show even higher efficiencies. The Anderson Quin Cycle (US Patent applied for) basically consists of 5 elements in the power cycle: A refrigeration system to cool and clean the inlet air before it enters the compressor that supplies air for the gas turbine; a gas turbine consisting of a compressor, combustor, and turbine; a steam boiler and steam turbine system using the heat from the exhaust gas out of the gas turbine; a vapor turbine cycle, which utilizes the condensed heat from the exhaust of the steam turbine and the exhaust gas heat leaving the steam boiler to operate a vapor turbine cycle which utilizes another fluid than water, in this case isobutane; and the fifth element consists of a gas cooler and heat pump system, which removes the heat from the exhaust gas to lower its temperature essentially to atmospheric temperature, and at the same time permits treatment of the exhaust gas to remove acid components such as sulfur dioxide and nitrogen oxides. Current industry accepted component characteristics were incorporated in the performance analysis of the overall cycle, ensuring accurate and meaningful operating predictions. The characteristics and performance of each of the elements are described. The thermal efficiency of the optimized calculated Anderson Quin Cycle is 62 percent.

  19. Consumer life-cycle cost impacts of energy-efficiency standards for residential-type central air conditioners and heat pumps

    E-Print Network [OSTI]

    Rosenquist, Gregory; Chan, Peter; Lekov, Alex; McMahon, James; Van Buskirk, Robert

    2001-01-01T23:59:59.000Z

    Central Air Conditioners and Heat Pumps Energy ConservationCentral Air Conditioners and Heat Pumps. Washington DC:Central Air Conditioners and Heat Pumps Energy Conservation

  20. Consumer life-cycle cost impacts of energy-efficiency standards for residential-type central air conditioners and heat pumps

    E-Print Network [OSTI]

    Rosenquist, Gregory; Chan, Peter; Lekov, Alex; McMahon, James; Van Buskirk, Robert

    2001-01-01T23:59:59.000Z

    Products: Central Air Conditioners and Heat Pumps EnergyResidential Central Air Conditioners and Heat Pumps.Products: Central Air Conditioners and Heat Pumps Energy

  1. Analysis of Energy, Environmental and Life Cycle Cost Reduction Potential of Ground Source Heat Pump (GSHP) in Hot and Humid Climate

    SciTech Connect (OSTI)

    Yong X. Tao; Yimin Zhu

    2012-04-26T23:59:59.000Z

    It has been widely recognized that the energy saving benefits of GSHP systems are best realized in the northern and central regions where heating needs are dominant or both heating and cooling loads are comparable. For hot and humid climate such as in the states of FL, LA, TX, southern AL, MS, GA, NC and SC, buildings have much larger cooling needs than heating needs. The Hybrid GSHP (HGSHP) systems therefore have been developed and installed in some locations of those states, which use additional heat sinks (such as cooling tower, domestic water heating systems) to reject excess heat. Despite the development of HGSHP the comprehensive analysis of their benefits and barriers for wide application has been limited and often yields non-conclusive results. In general, GSHP/HGSHP systems often have higher initial costs than conventional systems making short-term economics unattractive. Addressing these technical and financial barriers call for additional evaluation of innovative utility programs, incentives and delivery approaches. From scientific and technical point of view, the potential for wide applications of GSHP especially HGSHP in hot and humid climate is significant, especially towards building zero energy homes where the combined energy efficient GSHP and abundant solar energy production in hot climate can be an optimal solution. To address these challenges, this report presents gathering and analyzing data on the costs and benefits of GSHP/HGSHP systems utilized in southern states using a representative sample of building applications. The report outlines the detailed analysis to conclude that the application of GSHP in Florida (and hot and humid climate in general) shows a good potential.

  2. Heat pump system

    DOE Patents [OSTI]

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

    1982-01-01T23:59:59.000Z

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

  3. absorption heat pumps: Topics by E-print Network

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

    Heating capacity k jet nozzle Closed Cycles: AbsorptionAdsorption heat pump thermal compressor driven by waste heat1 Industrial heat pumps in Germany - potentials,...

  4. absorption heat pump: Topics by E-print Network

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

    Heating capacity k jet nozzle Closed Cycles: AbsorptionAdsorption heat pump thermal compressor driven by waste heat1 Industrial heat pumps in Germany - potentials,...

  5. Consumer life-cycle cost impacts of energy-efficiency standards for residential-type central air conditioners and heat pumps

    E-Print Network [OSTI]

    Rosenquist, Gregory; Chan, Peter; Lekov, Alex; McMahon, James; Van Buskirk, Robert

    2001-01-01T23:59:59.000Z

    Central Air Conditioners and Heat Pumps Energy ConservationW.R. Coleman. 1990. “Heat Pump Life and Compressor LongevityC.C.. 1990. “Predicting Future Heat Pump Production Volume

  6. Economics of Organic Rankine Cycle

    E-Print Network [OSTI]

    O'Brien, W. J.

    Flow Diagram of Rankine Cycle the power recovery. Thus, mechanical simplicity, good efficiency, small size and an inherent reliability make the Organic Rankine Cycle particularly suitable for extraction of power from low temperature waste heat... for recovering waste heat. Based on the waste heat temperature, electricity cost and quantity of heat available, Figure 3 can be used to determine whether a potential project has greater than 20% DCF (discounted cash flow) return (above the line) or less...

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

    E-Print Network [OSTI]

    Huang, Y.; Sun, D.

    2006-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Huang, Y.; Sun, D.

    2006-01-01T23:59:59.000Z

    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...

  9. 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) which employs a natural gas fired Stirling engine to drive a Rankine cycle vapor compressor is presently by the heat pump effect. The Stirling engine/Rankine cycle refrigeration loop heat pump being developed would

  10. Industrial and Commercial Heat Pump Applications in the United States

    E-Print Network [OSTI]

    Niess, R. C.

    compression cycle. Using readily available fluorocarbon refrigerants as the heat pump working fluid, this cycle is commonly used because of its wide application opportunities. Compressed Vapors Heat Pump Compressor Heat Sink PrOCess (Condenser... and refrigerants most commonly used and the open-cycle mechanical vapor compression heat pumps. Waste heat sources, heat loads served by heat pumps--and typical applications using heat pumps for large-scale space heating, domestic water heating, and industrial...

  11. Complex Compound Chemical Heat Pumps 

    E-Print Network [OSTI]

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

    1987-01-01T23:59:59.000Z

    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...

  12. Complex Compound Chemical Heat Pumps

    E-Print Network [OSTI]

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

    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...

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

    E-Print Network [OSTI]

    Kirol, L. D.

    for water and gas connections, and temperature variations. Recent work on heat pump cycles using complex compound reactions includes development of energy storage systems at laboratories in Europe (11) and the United States (12), and residential...ABSTRACT Chemical heat pumps utilize working fluids which undergo reversible chemical changes. Mechanically driven reactive heat pump cycles or, alternatively, hl~a: driven heat pumps in which either heat engine or heat pump working fluid...

  14. M. Bahrami ENSC 461 (S 11) Stirling Cycle 1 Stirling Cycle

    E-Print Network [OSTI]

    Bahrami, Majid

    M. Bahrami ENSC 461 (S 11) Stirling Cycle 1 Stirling Cycle In Stirling cycle, Carnot cycle). The regenerator is assumed to be reversible heat transfer device. Fig. 3-2: T-s and P-v diagrams for Stirling The Stirling cycle was invented by Robert Stirling in 1816. The execution of the Stirling cycle requires

  15. General syllabus for third-cycle studies in Heat Transfer TEMMVF00 This syllabus has been adopted by the Board of LTH, 3 November 2008

    E-Print Network [OSTI]

    -cycle qualifications. LTH shall primarily provide education leading to a PhD or licentiate in the fields of LTH The learning outcomes for third-cycle studies are given in the Higher Education Ordinance. 3.1 Licentiate Knowledge and understanding For a Licentiate the third-cycle student shall: - demonstrate knowledge

  16. Variable pressure power cycle and control system

    DOE Patents [OSTI]

    Goldsberry, Fred L. (Spring, TX)

    1984-11-27T23:59:59.000Z

    A variable pressure power cycle and control system that is adjustable to a variable heat source is disclosed. The power cycle adjusts itself to the heat source so that a minimal temperature difference is maintained between the heat source fluid and the power cycle working fluid, thereby substantially matching the thermodynamic envelope of the power cycle to the thermodynamic envelope of the heat source. Adjustments are made by sensing the inlet temperature of the heat source fluid and then setting a superheated vapor temperature and pressure to achieve a minimum temperature difference between the heat source fluid and the working fluid.

  17. Optimal operation of simple vapour compression cycles

    E-Print Network [OSTI]

    Skogestad, Sigurd

    is the air-conditioner (A/C). In colder regions a cycle operating in the opposite direction, the "heat pump. The coefficients of performance for a heating cycle (heat pump) and a cooling cycle (refrigerator, A/C) are defined as COPh = Qh Ws = h1 - h2 h1 - h4 and COPc = Qc Ws = h4 - h3 h1 - h4 (1.1) respectively. Heat pumps

  18. Vol. 16, No. 2 May 2006Global Energy and Water Cycle Experiment World Climate Research Programme

    E-Print Network [OSTI]

    's climate system is an energy cycle that converts absorbed solar radiation into heat and associated, its rapid rotation, and its elliptical orbit about the sun, the solar heating is neither uniform nor ARE A NET SINK OF ENERGY Left panel shows zonal, seasonal average generation of available potential energy

  19. M. Bahrami ENSC 461 (S 11) Refrigeration Cycle 1 Refrigeration Cycle

    E-Print Network [OSTI]

    Bahrami, Majid

    M. Bahrami ENSC 461 (S 11) Refrigeration Cycle 1 Refrigeration Cycle Heat flows in direction a low-temperature to high-temperature requires a refrigerator and/or heat pump. Refrigerators and heat of refrigerators and heat pumps is expressed in terms of coefficient of performance (COP): innet H HP innet L R W Q

  20. Rotary Vapor Compression Cycle Technology: A Pathway to Ultra...

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

    Cycle Technology: A Pathway to Ultra-Efficient Air Conditioning, Heating and Refrigeration Rotary Vapor Compression Cycle Technology: A Pathway to Ultra-Efficient Air...

  1. Self-heating and its possible relationship to chromospheric heating in slowly rotating stars

    E-Print Network [OSTI]

    Rogava, Andria; Poedts, Stefaan

    2009-01-01T23:59:59.000Z

    The efficiency of nonmodal self-heating by acoustic wave perturbations is examined. Considering different kinds of kinematically complex velocity patterns we show that nonmodal instabilities arising in these inhomogeneous flows may lead to significant amplification of acoustic waves. Subsequently, the presence of viscous dissipation damps these amplified waves and causes the energy transfer back to the background flow in the form of heat; viz. closes the "self-heating" cycle and contributes to the net heating of the flow patterns and the chromospheric network as a whole. The acoustic self-heating depends only on the presence of kinematically complex flows and dissipation. It is argued that together with other mechanisms of nonlinear nature the self-heating \\textit{may be} a probable additinal mechanism of nonmagnetic chromospheric heating in the Sun and other solar-type stars with slow rotation and extended convective regions.

  2. Industrial heat pumps in Germany -potentials, technological development

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    jet nozzle Closed Cycles: Absorption/Adsorption heat pump thermal compressor driven by waste heat, waste heat, waste water/air (heat recovery) Refrigerant R134a, R407C, R410A, R717 Heating capacity [k

  3. Fourier Heat Conduction as a phenomenon described within the scope of the Second Law

    E-Print Network [OSTI]

    Jesudason, Christopher G

    2014-01-01T23:59:59.000Z

    The historical development of the Carnot cycle necessitated the construction of isothermal and adiabatic pathways within the cycle that were also mechanically "reversible" which lead eventually to the Kelvin-Clausius development of the entropy function where the heat absorption is for the diathermal (isothermal) paths of the cycle only. It is deduced from traditional arguments that Fourier heat conduction involves mechanically "reversible" heat transfer with irreversible entropy increase. Here we model heat conduction as a thermodynamically reversible but mechanically irreversible process. The MD simulations conducted shows excellent agreement with the theory. Such views and results as these, if developed to a successful conclusion could imply that the Carnot cycle be viewed as describing a local process of energy-work conversion and that irreversible local processes might be brought within the scope of this cycle, implying a unified treatment of thermodynamically (i) irreversible, (ii) reversible, (iii) isot...

  4. Fourier Heat Conduction as a phenomenon described within the scope of the Second Law

    E-Print Network [OSTI]

    Christopher G. Jesudason

    2014-07-29T23:59:59.000Z

    The historical development of the Carnot cycle necessitated the construction of isothermal and adiabatic pathways within the cycle that were also mechanically "reversible" which lead eventually to the Kelvin-Clausius development of the entropy function where the heat absorption is for the diathermal (isothermal) paths of the cycle only. It is deduced from traditional arguments that Fourier heat conduction involves mechanically "reversible" heat transfer with irreversible entropy increase. Here we model heat conduction as a thermodynamically reversible but mechanically irreversible process. The MD simulations conducted shows excellent agreement with the theory. Such views and results as these, if developed to a successful conclusion could imply that the Carnot cycle be viewed as describing a local process of energy-work conversion and that irreversible local processes might be brought within the scope of this cycle, implying a unified treatment of thermodynamically (i) irreversible, (ii) reversible, (iii) isothermal and (iv) adiabatic processes.

  5. Superfluid thermodynamic cycle refrigerator

    DOE Patents [OSTI]

    Swift, G.W.; Kotsubo, V.Y.

    1992-12-22T23:59:59.000Z

    A cryogenic refrigerator cools a heat source by cyclically concentrating and diluting the amount of [sup 3]He in a single phase [sup 3]He-[sup 4]He solution. The [sup 3]He in superfluid [sup 4]He acts in a manner of an ideal gas in a vacuum. Thus, refrigeration is obtained using any conventional thermal cycle, but preferably a Stirling or Carnot cycle. A single phase solution of liquid [sup 3]He at an initial concentration in superfluid [sup 4]He is contained in a first variable volume connected to a second variable volume through a superleak device that enables free passage of [sup 4]He while restricting passage of [sup 3]He. The [sup 3]He is compressed (concentrated) and expanded (diluted) in a phased manner to carry out the selected thermal cycle to remove heat from the heat load for cooling below 1 K. 12 figs.

  6. Superfluid thermodynamic cycle refrigerator

    DOE Patents [OSTI]

    Swift, Gregory W. (Santa Fe, NM); Kotsubo, Vincent Y. (La Canada, CA)

    1992-01-01T23:59:59.000Z

    A cryogenic refrigerator cools a heat source by cyclically concentrating and diluting the amount of .sup.3 He in a single phase .sup.3 He-.sup.4 He solution. The .sup.3 He in superfluid .sup.4 He acts in a manner of an ideal gas in a vacuum. Thus, refrigeration is obtained using any conventional thermal cycle, but preferably a Stirling or Carnot cycle. A single phase solution of liquid .sup.3 He at an initial concentration in superfluid .sup.4 He is contained in a first variable volume connected to a second variable volume through a superleak device that enables free passage of .sup.4 He while restricting passage of .sup.3 He. The .sup.3 He is compressed (concentrated) and expanded (diluted) in a phased manner to carry out the selected thermal cycle to remove heat from the heat load for cooling below 1 K.

  7. Generated using version 3.0 of the official AMS LATEX template The seasonal cycle of atmospheric heating and temperature1

    E-Print Network [OSTI]

    Battisti, David

    heating and temperature1 Aaron Donohoe Massachusetts Institute of Technology, Cambridge, Massachusetts 2 Institute of Technology, Dept. of Earth, Atmospheric and Planetary Sciences, Room Number 54-918, 77 of the heating of the atmosphere is divided into a component due to direct5 solar absorption in the atmosphere

  8. Generated using version 3.1 of the official AMS LATEX template The seasonal cycle of atmospheric heating and temperature1

    E-Print Network [OSTI]

    Battisti, David

    heating and temperature1 Aaron Donohoe Massachusetts Institute of Technology, Cambridge, Massachusetts 2 Institute of Technology, Dept. of Earth, Atmospheric and Planetary Sciences, Room Number 54-918, 77 of the heating of the atmosphere is divided into a component due to direct5 solar absorption in the atmosphere

  9. Feasibility of Thermoelectrics for Waste Heat Recovery in Conventional Vehicles

    SciTech Connect (OSTI)

    Smith, K.; Thornton, M.

    2009-04-01T23:59:59.000Z

    Thermoelectric (TE) generators convert heat directly into electricity when a temperature gradient is applied across junctions of two dissimilar metals. The devices could increase the fuel economy of conventional vehicles by recapturing part of the waste heat from engine exhaust and generating electricity to power accessory loads. A simple vehicle and engine waste heat model showed that a Class 8 truck presents the least challenging requirements for TE system efficiency, mass, and cost; these trucks have a fairly high amount of exhaust waste heat, have low mass sensitivity, and travel many miles per year. These factors help maximize fuel savings and economic benefits. A driving/duty cycle analysis shows strong sensitivity of waste heat, and thus TE system electrical output, to vehicle speed and driving cycle. With a typical alternator, a TE system could allow electrification of 8%-15% of a Class 8 truck's accessories for 2%-3% fuel savings. More research should reduce system cost and improve economics.

  10. Cycle isolation monitoring

    SciTech Connect (OSTI)

    Svensen, L.M. III; Zeigler, J.R.; Todd, F.D.; Alder, G.C. [Santee Copper, Moncks Corner, SC (United States)

    2009-07-15T23:59:59.000Z

    There are many factors to monitor in power plants, but one that is frequently overlooked is cycle isolation. Often this is an area where plant personnel can find 'low hanging fruit' with great return on investment, especially high energy valve leakage. This type of leakage leads to increased heat rate, potential valve damage and lost generation. The fundamental question to ask is 'What is 100 Btu/kW-hr of heat rate worth to your plant? On a 600 MW coal-fired power plant, a 1% leakage can lead to an 81 Btu/kW-hr impact on the main steam cycle and a 64 Btu/kW-hr impact on the hot reheat cycle. The article gives advice on methods to assist in detecting leaking valves and to monitor cycle isolation. A software product, TP. Plus-CIM was designed to estimate flow rates of potentially leaking valves.

  11. Low Level Heat Recovery Technology

    E-Print Network [OSTI]

    O'Brien, W. J.

    1982-01-01T23:59:59.000Z

    level heat recovery technology. This paper discusses heat distribution systems, latest developments in absorption refrigeration and organic Rankine cycles, and pressure, minimization possibilities. The relative merits and economics of the various...

  12. Evaluation of water source heat pumps for the Juneau, Alaska Area

    SciTech Connect (OSTI)

    Jacobsen, J.J.; King, J.C.; Eisenhauer, J.L.; Gibson, C.I.

    1980-07-01T23:59:59.000Z

    The purposes of this project were to evaluate the technical and economic feasibility of water source heat pumps (WSHP) for use in Juneau, Alaska and to identify potential demonstration projects to verify their feasibility. Information is included on the design, cost, and availability of heat pumps, possible use of seawater as a heat source, heating costs with WSHP and conventional space heating systems, and life cycle costs for WSHP-based heating systems. The results showed that WSHP's are technically viable in the Juneau area, proper installation and maintenance is imperative to prevent equipment failures, use of WSHP would save fuel oil but increase electric power consumption. Life cycle costs for WSHP's are about 8% above that for electric resistance heating systems, and a field demonstration program to verify these results should be conducted. (LCL)

  13. Advanced thermochemical hydrogen cycles

    SciTech Connect (OSTI)

    Hollabaugh, C.M.; Bowman, M.G.

    1981-01-01T23:59:59.000Z

    The overall objective of this program is to contribute to the development of practical thermochemical cycles for the production of hydrogen from water. Specific goals are: investigate and evaluate the technical and economic viability of thermochemical cycles as an advanced technology for producing hydrogen from water; investigate and evaluate the engineering principles involved in interfacing individual thermochemical cycles with the different thermal energy sources (high temperature fission, solar, and fusion); and conduct a continuing research and development effort to evaluate the use of solid sulfates, oxides and other compounds as potentially advanced cycles and as alternates to H/sub 2/SO/sub 4/ based cycles. Basic thermochemistry studies have been completed for two different steps in the decomposition of bismuth sulfate. Two different bismuth sulfate cycles have been defined for different sulfuric acid strengths. The eventual best cycle will depend on energy required to form sulfuric acid at different concentrations. A solids decomposition facility has been constructed and practical studies of solid decompositions are being conducted. The facility includes a rotary kiln system and a dual-particle fluidized bed system. Evaluation of different types of cycles for coupling with different heat sources is continuing.

  14. Thermodynamic cycle in a cavity optomechanical system

    E-Print Network [OSTI]

    Hou Ian

    2014-02-16T23:59:59.000Z

    A cavity optomechanical system is initiated by a radiation pressure of a cavity field onto a mirror element acting as a quantum resonator. This radiation pressure can control the thermodynamic character of the mirror to some extent, such as cooling its effective temperature. Here we show that by properly engineering the spectral density of a thermal heat bath that interacts with a quantum system, the evolution of the quantum system can be effectively turned on and off. Inside a cavity optomechanical system, when the heat bath is realized by a multi-mode oscillator modeling of the mirror, this on-off effect translates to infusion or extraction of heat energy in and out of the cavity field, facilitating a four-stroke thermodynamic cycle.

  15. Determination of Thermal-Degradation Rates of Some Candidate Rankine-Cycle Organic Working Fluids for Conversion of Industrial Waste Heat Into Power 

    E-Print Network [OSTI]

    Jain, M. L.; Demirgian, J.; Krazinski, J. L.; Bushby, H.; Mattes, H.; Purcell, J.

    1984-01-01T23:59:59.000Z

    performance and economic on system performance, reliability, and overall considerations (rate of return on investment economics have impeded widespread development and [ROI]), six organic fluids were identified to deployment of organic Rankine-cycle power... included with the GC unit inte grates the peaks and produc s a report consisting of retention time, peak area, and area percent. The detector's analog output is connected via an A/D converter to a Perkin Elmer (PE) Sigma 15 chromatography data station...

  16. AN AMMONIA-WATER ABSORPTION-HIAT-PUMP CYCLE Donald Kuhlenschmidt, Member ASHRAE

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    to an air-source heating- only heat-pump cycle which delivers its heat in- doors via circulating liquid,000 Btuh) input unit reported. KLY WORDS Absorption Heat-pump Air conditioning heating Ammonia Donald conditioning chillers. The authors are involved in a project to use this cycle in an air source heat pump

  17. Evaluation and Optimization of a Supercritical Carbon Dioxide Power Conversion Cycle for Nuclear Applications

    SciTech Connect (OSTI)

    Edwin A. Harvego; Michael G. McKellar

    2011-05-01T23:59:59.000Z

    There have been a number of studies involving the use of gases operating in the supercritical mode for power production and process heat applications. Supercritical carbon dioxide (CO2) is particularly attractive because it is capable of achieving relatively high power conversion cycle efficiencies in the temperature range between 550°C and 750°C. Therefore, it has the potential for use with any type of high-temperature nuclear reactor concept, assuming reactor core outlet temperatures of at least 550°C. The particular power cycle investigated in this paper is a supercritical CO2 Recompression Brayton Cycle. The CO2 Recompression Brayton Cycle can be used as either a direct or indirect power conversion cycle, depending on the reactor type and reactor outlet temperature. The advantage of this cycle when compared to the helium Brayton Cycle is the lower required operating temperature; 550°C versus 850°C. However, the supercritical CO2 Recompression Brayton Cycle requires an operating pressure in the range of 20 MPa, which is considerably higher than the required helium Brayton cycle operating pressure of 8 MPa. This paper presents results of analyses performed using the UniSim process analyses software to evaluate the performance of the supercritical CO2 Brayton Recompression Cycle for different reactor outlet temperatures. The UniSim model assumed a 600 MWt reactor power source, which provides heat to the power cycle at a maximum temperature of between 550°C and 750°C. The UniSim model used realistic component parameters and operating conditions to model the complete power conversion system. CO2 properties were evaluated, and the operating range for the cycle was adjusted to take advantage of the rapidly changing conditions near the critical point. The UniSim model was then optimized to maximize the power cycle thermal efficiency at the different maximum power cycle operating temperatures. The results of the analyses showed that power cycle thermal efficiencies in the range of 40 to 50% can be achieved.

  18. Optimization and Comparison of Direct and Indirect Supercritical Carbon Dioxide Power Plant Cycles for Nuclear Applications

    SciTech Connect (OSTI)

    Edwin A. Harvego; Michael G. McKellar

    2011-11-01T23:59:59.000Z

    There have been a number of studies involving the use of gases operating in the supercritical mode for power production and process heat applications. Supercritical carbon dioxide (CO2) is particularly attractive because it is capable of achieving relatively high power conversion cycle efficiencies in the temperature range between 550 C and 750 C. Therefore, it has the potential for use with any type of high-temperature nuclear reactor concept, assuming reactor core outlet temperatures of at least 550 C. The particular power cycle investigated in this paper is a supercritical CO2 Recompression Brayton Cycle. The CO2 Recompression Brayton Cycle can be used as either a direct or indirect power conversion cycle, depending on the reactor type and reactor outlet temperature. The advantage of this cycle when compared to the helium Brayton cycle is the lower required operating temperature; 550 C versus 850 C. However, the supercritical CO2 Recompression Brayton Cycle requires an operating pressure in the range of 20 MPa, which is considerably higher than the required helium Brayton cycle operating pressure of 8 MPa. This paper presents results of analyses performed using the UniSim process analyses software to evaluate the performance of both a direct and indirect supercritical CO2 Brayton Recompression cycle for different reactor outlet temperatures. The direct supercritical CO2 cycle transferred heat directly from a 600 MWt reactor to the supercritical CO2 working fluid supplied to the turbine generator at approximately 20 MPa. The indirect supercritical CO2 cycle assumed a helium-cooled Very High Temperature Reactor (VHTR), operating at a primary system pressure of approximately 7.0 MPa, delivered heat through an intermediate heat exchanger to the secondary indirect supercritical CO2 Brayton Recompression cycle, again operating at a pressure of about 20 MPa. For both the direct and indirect cycles, sensitivity calculations were performed for reactor outlet temperature between 550 C and 850 C. The UniSim models used realistic component parameters and operating conditions to model the complete reactor and power conversion systems. CO2 properties were evaluated, and the operating ranges of the cycles were adjusted to take advantage of the rapidly changing properties of CO2 near the critical point. The results of the analyses showed that, for the direct supercritical CO2 power cycle, thermal efficiencies in the range of 40 to 50% can be achieved. For the indirect supercritical CO2 power cycle, thermal efficiencies were approximately 10% lower than those obtained for the direct cycle over the same reactor outlet temperature range.

  19. Supercritical carbon dioxide cycle control analysis.

    SciTech Connect (OSTI)

    Moisseytsev, A.; Sienicki, J. J. (Nuclear Engineering Division)

    2011-04-11T23:59:59.000Z

    This report documents work carried out during FY 2008 on further investigation of control strategies for supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle energy converters. The main focus of the present work has been on investigation of the S-CO{sub 2} cycle control and behavior under conditions not covered by previous work. An important scenario which has not been previously calculated involves cycle operation for a Sodium-Cooled Fast Reactor (SFR) following a reactor scram event and the transition to the primary coolant natural circulation and decay heat removal. The Argonne National Laboratory (ANL) Plant Dynamics Code has been applied to investigate the dynamic behavior of the 96 MWe (250 MWt) Advanced Burner Test Reactor (ABTR) S-CO{sub 2} Brayton cycle following scram. The timescale for the primary sodium flowrate to coast down and the transition to natural circulation to occur was calculated with the SAS4A/SASSYS-1 computer code and found to be about 400 seconds. It is assumed that after this time, decay heat is removed by the normal ABTR shutdown heat removal system incorporating a dedicated shutdown heat removal S-CO{sub 2} pump and cooler. The ANL Plant Dynamics Code configured for the Small Secure Transportable Autonomous Reactor (SSTAR) Lead-Cooled Fast Reactor (LFR) was utilized to model the S-CO{sub 2} Brayton cycle with a decaying liquid metal coolant flow to the Pb-to-CO{sub 2} heat exchangers and temperatures reflecting the decaying core power and heat removal by the cycle. The results obtained in this manner are approximate but indicative of the cycle transient performance. The ANL Plant Dynamics Code calculations show that the S-CO{sub 2} cycle can operate for about 400 seconds following the reactor scram driven by the thermal energy stored in the reactor structures and coolant such that heat removal from the reactor exceeds the decay heat generation. Based on the results, requirements for the shutdown heat removal system may be defined. In particular, the peak heat removal capacity of the shutdown heat removal loop may be specified to be 1.1 % of the nominal reactor power. An investigation of the oscillating cycle behavior calculated by the ANL Plant Dynamics Code under specific conditions has been carried out. It has been found that the calculation of unstable operation of the cycle during power reduction to 0 % may be attributed to the modeling of main compressor operation. The most probable reason for such instabilities is the limit of applicability of the currently used one-dimensional compressor performance subroutines which are based on empirical loss coefficients. A development of more detailed compressor design and performance models is required and is recommended for future work in order to better investigate and possibly eliminate the calculated instabilities. Also, as part of such model development, more reliable surge criteria should be developed for compressor operation close to the critical point. It is expected that more detailed compressor models will be developed as a part of validation of the Plant Dynamics Code through model comparison with the experiment data generated in the small S-CO{sub 2} loops being constructed at Barber-Nichols Inc. and Sandia National Laboratories (SNL). Although such a comparison activity had been planned to be initiated in FY 2008, data from the SNL compression loop currently in operation at Barber Nichols Inc. has not yet become available by the due date of this report. To enable the transient S-CO{sub 2} cycle investigations to be carried out, the ANL Plant Dynamics Code for the S-CO{sub 2} Brayton cycle was further developed and improved. The improvements include further optimization and tuning of the control mechanisms as well as an adaptation of the code for reactor systems other than the Lead-Cooled Fast Reactor (LFR). Since the focus of the ANL work on S-CO{sub 2} cycle development for the majority of the current year has been on the applicability of the cycle to SFRs, work has started on modification of the ANL Plant Dynamics Code to allow

  20. Absorption heat pump system

    DOE Patents [OSTI]

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

    1984-01-01T23:59:59.000Z

    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.

  1. Applied heat transfer

    SciTech Connect (OSTI)

    Ganapathy, V.

    1982-01-01T23:59:59.000Z

    Heat transfer principles are discussed with emphasis on the practical aspects of the problems. Correlations for heat transfer and pressure drop from several worldwide sources for flow inside and outside of tubes, including finned tubes are presented, along with design and performance calculations of heat exchangers economizers, air heaters, condensers, waste-heat boilers, fired heaters, superheaters, and boiler furnaces. Vibration analysis for tube bundles and heat exchangers are also discussed, as are estimating gas-mixture properties at atmospheric and elevated pressures and life-cycle costing techniques. (JMT)

  2. Heat Pump for High School Heat Recovery 

    E-Print Network [OSTI]

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

    2006-01-01T23:59:59.000Z

    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...

  3. atom heat processing: Topics by E-print Network

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

    accepted by industry, will fall into one of the three cycle categories. In a closed cycle heat pump, a working fluid exchanges heat... Priebe, S. J.; Chappell, R. N. 16 TOPICAL...

  4. Dissipative heat engine is thermodynamically inconsistent

    E-Print Network [OSTI]

    A. M. Makarieva; V. G. Gorshkov

    2009-10-05T23:59:59.000Z

    A heat engine operating on the basis of the Carnot cycle is considered, where the mechanical work performed is dissipated within the engine at the temperature of the warmer isotherm and the resulting heat is added to the engine together with an external heat input. The resulting work performed by the engine per cycle is increased at the expense of dissipated work produced in the previous cycle. It is shown that such a dissipative heat engine is thermodynamically inconsistent violating the first and second laws of thermodynamics. The existing physical models employing the dissipative heat engine concept, in particular, the heat engine model of hurricane development, are physically invalid.

  5. Industrial Heat Pump Case Study

    E-Print Network [OSTI]

    Wagner, J. R.; Brush, F. C.

    with operating the evaporator. The open-cycle heat pump design uses an electrically driven centrifugal compressor to recover the latent heat of the water vapor generated by the evaporator. (Steam was the original heat source but is now only needed for start...

  6. Ceramic heat-exchanger applications study

    SciTech Connect (OSTI)

    McFarlin, D.J.; Sgamboti, C.T.; Lessard, R.D.

    1982-10-01T23:59:59.000Z

    To put the potential benefits of ceramic heat exchangers (CHX) applications into quantitative perspective, several industrial cogeneration and electric utiity power generation systems were surveyed and evaluated. This study was focused on coal-based fuel fired applications, for which system performance and economic assessments were made. Seven CHX applications in the industrial cogeneration sector were selected for evaluation. These include (1) Gasified Coal-Fired Gas Turbine, (2) Pressurized Fluidized Bed Combustor (PFBC)-Gas Turbine, (3) Atmospheric Fluidized Bed Combustor (AFBC)-Gas Turbine, (4 and 5) AFBC Combined Cycle with and without reheat and (6 and 7) Indirect Coal-Fired Gas Turbine and Combined Cycle. The performance and economics of these cogeneration systems were evaluated and compared with other competing systems (both advanced and State-of-the-Art). For the electric utility power generation sector five applications utilizing a CHX were selected and evaluated; their performance and cost factors were compared to those of a reference pulverized coal-fired steam plant with flue gas desulfurization. These five applications included (1) PFBC-Combined Cycle, (2) AFBC-Combined Cycle, (3) Industrial Coal Gasifier-Combined Cycle, (4) Indirect Coal-Fired Combined Cycle, and (5) Indirect Coal-Fired Simple Cycle. Of the five CHX applications evaluated in the power generation sector, only the AFBC system showed a clear gain over the reference pulverized coal system.

  7. Performance improvement options for the supercritical carbon dioxide brayton cycle.

    SciTech Connect (OSTI)

    Moisseytsev, A.; Sienicki, J. J.; Nuclear Engineering Division

    2008-07-17T23:59:59.000Z

    The supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle is under development at Argonne National Laboratory as an advanced power conversion technology for Sodium-Cooled Fast Reactors (SFRs) as well as other Generation IV advanced reactors as an alternative to the traditional Rankine steam cycle. For SFRs, the S-CO{sub 2} Brayton cycle eliminates the need to consider sodium-water reactions in the licensing and safety evaluation, reduces the capital cost of the SFR plant, and increases the SFR plant efficiency. Even though the S-CO{sub 2} cycle has been under development for some time and optimal sets of operating parameters have been determined, those earlier development and optimization studies have largely been directed at applications to other systems such as gas-cooled reactors which have higher operating temperatures than SFRs. In addition, little analysis has been carried out to investigate cycle configurations deviating from the selected 'recompression' S-CO{sub 2} cycle configuration. In this work, several possible ways to improve S-CO{sub 2} cycle performance for SFR applications have been identified and analyzed. One set of options incorporates optimization approaches investigated previously, such as variations in the maximum and minimum cycle pressure and minimum cycle temperature, as well as a tradeoff between the component sizes and the cycle performance. In addition, the present investigation also covers options which have received little or no attention in the previous studies. Specific options include a 'multiple-recompression' cycle configuration, intercooling and reheating, as well as liquid-phase CO{sub 2} compression (pumping) either by CO{sub 2} condensation or by a direct transition from the supercritical to the liquid phase. Some of the options considered did not improve the cycle efficiency as could be anticipated beforehand. Those options include: a double recompression cycle, intercooling between the compressor stages, and reheating between the turbine stages. Analyses carried out as part of the current investigation confirm the possibilities of improving the cycle efficiency that have been identified in previous investigations. The options in this group include: increasing the heat exchanger and turbomachinery sizes, raising of the cycle high end pressure (although the improvement potential of this option is very limited), and optimization of the low end temperature and/or pressure to operate as close to the (pseudo) critical point as possible. Analyses carried out for the present investigation show that significant cycle performance improvement can sometimes be realized if the cycle operates below the critical temperature at its low end. Such operation, however, requires the availability of a heat sink with a temperature lower than 30 C for which applicability of this configuration is dependent upon the climate conditions where the plant is constructed (i.e., potential performance improvements are site specific). Overall, it is shown that the S-CO{sub 2} Brayton cycle efficiency can potentially be increased to 45 %, if a low temperature heat sink is available and incorporation of larger components (e.g.., heat exchangers or turbomachinery) having greater component efficiencies does not significantly increase the overall plant cost.

  8. SENSIBLE HEAT STORAGE FOR A SOLAR THERMAL POWER PLANT

    E-Print Network [OSTI]

    Baldwin, Thomas F.

    2011-01-01T23:59:59.000Z

    Topping of the Steam-Cycle Power Plant . A COMPARISON OFTOPPING OF THE STEAM-CYCLE POWER PLANT The proposed solarreceiver and a steam-cycle power plant. To transport heat, a

  9. A simple quantum heat engine

    E-Print Network [OSTI]

    Jacques Arnaud; Laurent Chusseau; Fabrice Philippe

    2003-06-02T23:59:59.000Z

    Quantum heat engines employ as working agents multi-level systems instead of gas-filled cylinders. We consider particularly two-level agents such as electrons immersed in a magnetic field. Work is produced in that case when the electrons are being carried from a high-magnetic-field region into a low-magnetic-field region. In watermills, work is produced instead when some amount of fluid drops from a high-altitude reservoir to a low-altitude reservoir. We show that this purely mechanical engine may in fact be considered as a two-level quantum heat engine, provided the fluid is viewed as consisting of n molecules of weight one and N-n molecules of weight zero. Weight-one molecules are analogous to electrons in their higher energy state, while weight-zero molecules are analogous to electrons in their lower energy state. More generally, fluids consist of non-interacting molecules of various weights. It is shown that, not only the average value of the work produced per cycle, but also its fluctuations, are the same for mechanical engines and quantum (Otto) heat engines. The reversible Carnot cycles are approached through the consideration of multiple sub-reservoirs.

  10. Advanced regenerative absorption refrigeration cycles

    DOE Patents [OSTI]

    Dao, Kim (14 Nace Ave., Piedmont, CA 94611)

    1990-01-01T23:59:59.000Z

    Multi-effect regenerative absorption cycles which provide a high coefficient of performance (COP) at relatively high input temperatures. An absorber-coupled double-effect regenerative cycle (ADR cycle) (10) is provided having a single-effect absorption cycle (SEA cycle) (11) as a topping subcycle and a single-effect regenerative absorption cycle (1R cycle) (12) as a bottoming subcycle. The SEA cycle (11) includes a boiler (13), a condenser (21), an expansion device (28), an evaporator (31), and an absorber (40), all operatively connected together. The 1R cycle (12) includes a multistage boiler (48), a multi-stage resorber (51), a multisection regenerator (49) and also uses the condenser (21), expansion device (28) and evaporator (31) of the SEA topping subcycle (11), all operatively connected together. External heat is applied to the SEA boiler (13) for operation up to about 500 degrees F., with most of the high pressure vapor going to the condenser (21) and evaporator (31) being generated by the regenerator (49). The substantially adiabatic and isothermal functioning of the SER subcycle (12) provides a high COP. For higher input temperatures of up to 700 degrees F., another SEA cycle (111) is used as a topping subcycle, with the absorber (140) of the topping subcycle being heat coupled to the boiler (13) of an ADR cycle (10). The 1R cycle (12) itself is an improvement in that all resorber stages (50b-f) have a portion of their output pumped to boiling conduits (71a-f) through the regenerator (49), which conduits are connected to and at the same pressure as the highest pressure stage (48a) of the 1R multistage boiler (48).

  11. Author's personal copy Pyroelectric waste heat energy harvesting using heat conduction

    E-Print Network [OSTI]

    Pilon, Laurent

    Author's personal copy Pyroelectric waste heat energy harvesting using heat conduction Felix Y. Lee heat harvesting Olsen cycle a b s t r a c t Waste heat can be directly converted into electrical energy Ltd. All rights reserved. 1. Introduction Large amounts of waste heat are released as a by

  12. High-speed thermal cycling system and method of use

    DOE Patents [OSTI]

    Hansen, A.D.A.; Jaklevic, J.M.

    1996-04-16T23:59:59.000Z

    A thermal cycling system and method of use are described. The thermal cycling system is based on the circulation of temperature-controlled water directly to the underside of thin-walled polycarbonate plates. The water flow is selected from a manifold fed by pumps from heated reservoirs. The plate wells are loaded with typically 15-20 microliters of reagent mix for the PCR process. Heat transfer through the thin polycarbonate is sufficiently rapid that the contents reach thermal equilibrium with the water in less than 15 seconds. Complete PCR amplification runs of 40 three-step cycles have been performed in as little as 14.5 minutes, with the results showing substantially enhanced specificity compared to conventional technology requiring run times in excess of 100 minutes. The plate clamping station is designed to be amenable to robotic loading and unloading of the system. It includes a heated lid, thus eliminating the need for mineral oil overlay of the reactants. The present system includes three or more plate holder stations, fed from common reservoirs but operating with independent switching cycles. The system can be modularly expanded. 13 figs.

  13. High-speed thermal cycling system and method of use

    DOE Patents [OSTI]

    Hansen, Anthony D. A. (Berkely, CA); Jaklevic, Joseph M. (Lafayette, CA)

    1996-01-01T23:59:59.000Z

    A thermal cycling system and method of use are described. The thermal cycling system is based on the-circulation of temperature-controlled water directly to the underside of thin-walled polycarbonate microtiter plates. The water flow is selected from a manifold fed by pumps from heated reservoirs. The plate wells are loaded with typically 15-20 .mu.l of reagent mix for the PCR process. Heat transfer through the thin polycarbonate is sufficiently rapid that the contents reach thermal equilibrium with the water in less than 15 seconds. Complete PCR amplification runs of 40 three-step cycles have been performed in as little as 14.5 minutes, with the results showing substantially enhanced specificity compared to conventional technology requiring run times in excess of 100 minutes. The plate clamping station is designed to be amenable to robotic loading and unloading of the system. It includes a heated lid, thus eliminating the need for mineral oil overlay of the reactants. The present system includes three or more plate holder stations, fed from common reservoirs but operating with independent switching cycles. The system can be modularly expanded.

  14. Gas turbine cycles with solid oxide fuel cells. Part 2: A detailed study of a gas turbine cycle with an integrated internal reforming solid oxide fuel cell

    SciTech Connect (OSTI)

    Harvey, S.P.; Richter, H.J. (Dartmouth Coll., Hanover, NH (United States). Thayer School of Engineering)

    1994-12-01T23:59:59.000Z

    The energy conversion efficiency can be improved if immediate contact of air and fuel is prevented. One means to prevent this immediate contact is the use of fuel cell technology. High-temperature solid oxide fuel cells (SOFC) have many features that make them attractive for utility and industrial applications. However, in view of their high operating temperatures and the incomplete nature of the fuel oxidation process, such fuel cells must be combined with conventional power generation technology to develop power plant configurations that are both functional and efficient. Most fuel cell cycles proposed in the literature use a high-temperature fuel cell running at ambient pressure and a steam bottoming cycle to recover the waste heat generated by the fuel cell. With such cycles, the inherent flexibility and shorter start-up time characteristics of the fuel cell are lost. In Part 1 of this paper, a pressurized cycle using a solid oxide fuel cell and an integrated gas turbine bottoming cycle was presented. The cycle is simpler than most cycles with steam bottoming cycles and more suited to flexible power generation. In this paper, the authors will discuss this cycle in more detail, with an in-depth discussion of all cycle component characteristics and losses. In particular, they will make use of the fuel cell's internal fuel reforming capability. The optimal cycle parameters were obtained based on calculations performed using Aspen Technology's ASPEN PLUS process simulation software and a fuel cell simulator developed by Argonne National Laboratory. The efficiency of the proposed cycle is 68.1%. A preliminary economic assessment of the cycle shows that it should compare favorable with a state-of-the-art combined cycle plant on a cost per MWe basis.

  15. Stirling cycle rotary engine

    SciTech Connect (OSTI)

    Chandler, J.A.

    1988-06-28T23:59:59.000Z

    A Stirling cycle rotary engine for producing mechanical energy from heat generated by a heat source external to the engine, the engine including: an engine housing having an interior toroidal cavity with a central housing axis for receiving a working gas, the engine housing further having a cool as inlet port, a compressed gas outlet port, a heated compressed gas inlet port, and a hot exhaust gas outlet port at least three rotors each fixedly mounted to a respective rotor shaft and independently rotatable within the toroidal cavity about the central axis; each of the rotors including a pair of rotor blocks spaced radially on diametrically opposing sides of the respective rotor shaft, each rotor block having a radially fixed curva-linear outer surface for sealed rotational engagement with the engine housing.

  16. Open cycle thermoacoustics

    SciTech Connect (OSTI)

    Reid, Robert Stowers

    2000-01-01T23:59:59.000Z

    A new type of thermodynamic device combining a thermodynamic cycle with the externally applied steady flow of an open thermodynamic process is discussed and experimentally demonstrated. The gas flowing through this device can be heated or cooled in a series of semi-open cyclic steps. The combination of open and cyclic flows makes possible the elimination of some or all of the heat exchangers (with their associated irreversibility). Heat is directly exchanged with the process fluid as it flows through the device when operating as a refrigerator, producing a staging effect that tends to increase First Law thermodynamic efficiency. An open-flow thermoacoustic refrigerator was built to demonstrate this concept. Several approaches are presented that describe the physical characteristics of this device. Tests have been conducted on this refrigerator with good agreement with a proposed theory.

  17. Development of a Heat Transfer Model for the Integrated Facade Heating

    E-Print Network [OSTI]

    Gong, X.; Archer, D. H.; Claridge, D. E.

    2007-01-01T23:59:59.000Z

    the heat transfer process of facade heating (mullion radiators) in a pilot research project in Pittsburgh, PA. The heat transfer model for facade heating is developed and verified by measured data. The comparison shows that the heat transfer model predicts...

  18. Development of a Heat Transfer Model for the Integrated Facade Heating 

    E-Print Network [OSTI]

    Gong, X.; Archer, D. H.; Claridge, D. E.

    2007-01-01T23:59:59.000Z

    the heat transfer process of facade heating (mullion radiators) in a pilot research project in Pittsburgh, PA. The heat transfer model for facade heating is developed and verified by measured data. The comparison shows that the heat transfer model predicts...

  19. The effects of expansion devices on the transient response characteristics of the air-source heat pump during the reverse cycle defrost

    E-Print Network [OSTI]

    Peterson, Kurt T.

    1988-01-01T23:59:59.000Z

    using fast and slow response TXVs and different diameter orifices. The overall performance of each test was analyzed as well as a detailed investigation . of the refrigerant dynamics. The results of the investigation for TXVs indicated bulb.../suction line contact was more critical to the response of the TXV than the internal bulb charge. The orifice investigation showed a general trend of faster defrost times with larger orifices, although the largest orifices allowed liquid refrigerant...

  20. Highly efficient 6-stroke engine cycle with water injection

    DOE Patents [OSTI]

    Szybist, James P; Conklin, James C

    2012-10-23T23:59:59.000Z

    A six-stroke engine cycle having improved efficiency. Heat is recovered from the engine combustion gases by using a 6-stroke engine cycle in which combustion gases are partially vented proximate the bottom-dead-center position of the fourth stroke cycle, and water is injected proximate the top-dead-center position of the fourth stroke cycle.

  1. Rankine and Brayton Cycle Cogeneration for Glass Melting

    E-Print Network [OSTI]

    Hnat, J. G.; Patten, J. S.; Sheth, P. R.

    1981-01-01T23:59:59.000Z

    Comparisons are made of the performance and installation costs of Rankine and Brayton power cycles when applied to waste heat recovery from a 350 ton/day container glass furnace. The power cycles investigation included: a) a conventional steam...

  2. atmospheric water cycle: Topics by E-print Network

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

    Geosciences Websites Summary: is decided. Three orbital cycles combine to modulate the North- ern Hemisphere solar heating. The axisWHAT CAUSED THE GLACIALINTERGLACIAL...

  3. Sandia National Laboratories: Nuclear Fuel Cycle Options Catalog

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

    (NESL) Brayton Lab SCO2 Brayton Cycle Technology Videos Heat Exchanger Development Diffusion Bonding Characterization Mechanical Testing Deep Borehole Disposal Nuclear...

  4. Analysis of Energy, Environmental and Life Cycle Cost Reduction...

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

    Analysis of Energy, Environmental and Life Cycle Cost Reduction Potential of Ground Source Heat Pump (GSHP) in Hot and Humid Climate Analysis of Energy, Environmental and Life...

  5. Analysis of Energy, Environmental and Life Cycle Cost Reduction...

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

    Energy, Environmental and Life Cycle Cost Reduction Potential of Ground Source Heat Pump (GSHP) in Hot and Humid Climate Principal Investigator: Y.-X. Tao Florida International...

  6. advanced combined cycle: Topics by E-print Network

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

    4 Combined Cycle Combustion Turbine Background Primary Components Gas-fired combustion turbine (s) Heat recovery steam generator (s) - HRSG with or without duct firing Natural gas...

  7. Selection of Working Fluids for the Organic Rankine Cycle

    E-Print Network [OSTI]

    West, H. H.; Patton, J. M.; Starling, K. E.

    1979-01-01T23:59:59.000Z

    The subject of selecting working fluid and process operating conditions for the waste heat binary power cycle is addressed herein. The waste heat temperature range from 300 F to 500 F was considered the economic resource range. The available...

  8. Cascade Reverse Osmosis Air Conditioning System: Cascade Reverse Osmosis and the Absorption Osmosis Cycle

    SciTech Connect (OSTI)

    None

    2010-09-01T23:59:59.000Z

    BEETIT Project: Battelle is developing a new air conditioning system that uses a cascade reverse osmosis (RO)-based absorption cycle. Analyses show that this new cycle can be as much as 60% more efficient than vapor compression, which is used in 90% of air conditioners. Traditional vapor-compression systems use polluting liquids for a cooling effect. Absorption cycles use benign refrigerants such as water, which is absorbed in a salt solution and pumped as liquid—replacing compression of vapor. The refrigerant is subsequently separated from absorbing salt using heat for re-use in the cooling cycle. Battelle is replacing thermal separation of refrigerant with a more efficient reverse osmosis process. Research has shown that the cycle is possible, but further investment will be needed to reduce the number of cascade reverse osmosis stages and therefore cost.

  9. Water Vapor and Mechanical Work: A Comparison of Carnot and Steam Cycles OLIVIER PAULUIS

    E-Print Network [OSTI]

    Pauluis, Olivier M.

    Water Vapor and Mechanical Work: A Comparison of Carnot and Steam Cycles OLIVIER PAULUIS Center in the atmosphere is discussed here by comparing two idealized heat engines: the Carnot cycle and the steam cycle. A steam cycle transports water from a warm moist source to a colder dryer sink. It acts as a heat engine

  10. Carnot Cycle at Finite Power: Attainability of Maximal Efficiency

    E-Print Network [OSTI]

    Armen E. Allahverdyan; Karen V. Hovhannisyan; Alexey V. Melkikh; Sasun G. Gevorkian

    2013-12-12T23:59:59.000Z

    We want to understand whether and to which extent the maximal (Carnot) efficiency for heat engines can be reached at a finite power. To this end we generalize the Carnot cycle so that it is not restricted to slow processes. We show that for realistic (i.e. not purposefully-designed) engine-bath interactions, the work-optimal engine performing the generalized cycle close to the maximal efficiency has a long cycle time and hence vanishing power. This aspect is shown to relate to the theory of computational complexity. A physical manifestation of the same effect is the Levinthal's paradox in the protein folding problem. The resolution of this paradox for realistic proteins allows to construct engines that can extract at a finite power 40% of the maximally possible work reaching 90% of the maximal efficiency. For purposefully designed engine-bath interactions, the Carnot efficiency is achievable at a large power.

  11. Rankine cycle system and method

    DOE Patents [OSTI]

    Ernst, Timothy C.; Nelson, Christopher R.

    2014-09-09T23:59:59.000Z

    A Rankine cycle waste heat recovery system uses a receiver with a maximum liquid working fluid level lower than the minimum liquid working fluid level of a sub-cooler of the waste heat recovery system. The receiver may have a position that is physically lower than the sub-cooler's position. A valve controls transfer of fluid between several of the components in the waste heat recovery system, especially from the receiver to the sub-cooler. The system may also have an associated control module.

  12. Chemical heat pump

    DOE Patents [OSTI]

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

    1980-01-01T23:59:59.000Z

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

  13. CONTROL SYSTEM FOR SOLAR HEATING and COOLING

    E-Print Network [OSTI]

    Dols, C.

    2010-01-01T23:59:59.000Z

    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 (

  14. Dual Heating and Cooling Sorption Heat Pump for a Food Plant

    E-Print Network [OSTI]

    Rockenfeller, U.; Dooley, B.

    Complex compound sorption reactions are ideally suited for use in high temperature lift industrial heat pump cycles. Complex compound heat pumping and refrigeration provides a number of energy-saving advantages over present vapor compression systems...

  15. Orbital Resonance and Solar Cycles

    E-Print Network [OSTI]

    P. A. Semi

    2009-03-29T23:59:59.000Z

    We present an analysis of planetary moves, encoded in DE406 ephemerides. We show resonance cycles between most planets in Solar System, of differing quality. The most precise resonance - between Earth and Venus, which not only stabilizes orbits of both planets, locks planet Venus rotation in tidal locking, but also affects the Sun: This resonance group (E+V) also influences Sunspot cycles - the position of syzygy between Earth and Venus, when the barycenter of the resonance group most closely approaches the Sun and stops for some time, relative to Jupiter planet, well matches the Sunspot cycle of 11 years, not only for the last 400 years of measured Sunspot cycles, but also in 1000 years of historical record of "severe winters". We show, how cycles in angular momentum of Earth and Venus planets match with the Sunspot cycle and how the main cycle in angular momentum of the whole Solar system (854-year cycle of Jupiter/Saturn) matches with climatologic data, assumed to show connection with Solar output power and insolation. We show the possible connections between E+V events and Solar global p-Mode frequency changes. We futher show angular momentum tables and charts for individual planets, as encoded in DE405 and DE406 ephemerides. We show, that inner planets orbit on heliocentric trajectories whereas outer planets orbit on barycentric trajectories.

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

    SciTech Connect (OSTI)

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

    1992-08-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    1992-01-01T23:59:59.000Z

    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.

  18. Absorption-heat-pump system

    DOE Patents [OSTI]

    Grossman, G.; Perez-Blanco, H.

    1983-06-16T23:59:59.000Z

    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.

  19. NAIHC Convention and Trade Show

    Broader source: Energy.gov [DOE]

    The National American Indian Housing Council's (NAIHC) most longstanding Annual Event, the 39th Annual NAIHC Convention and Trade Show is an opportunity to learn about tribal housing, attend...

  20. High efficiency Brayton cycles using LNG

    DOE Patents [OSTI]

    Morrow, Charles W. (Albuquerque, NM)

    2006-04-18T23:59:59.000Z

    A modified, closed-loop Brayton cycle power conversion system that uses liquefied natural gas as the cold heat sink media. When combined with a helium gas cooled nuclear reactor, achievable efficiency can approach 68 76% (as compared to 35% for conventional steam cycle power cooled by air or water). A superheater heat exchanger can be used to exchange heat from a side-stream of hot helium gas split-off from the primary helium coolant loop to post-heat vaporized natural gas exiting from low and high-pressure coolers. The superheater raises the exit temperature of the natural gas to close to room temperature, which makes the gas more attractive to sell on the open market. An additional benefit is significantly reduced costs of a LNG revaporization plant, since the nuclear reactor provides the heat for vaporization instead of burning a portion of the LNG to provide the heat.

  1. Managing Beef Cattle for Show

    E-Print Network [OSTI]

    Herd, Dennis B.; Boleman, Chris; Boleman, Larry L.

    2001-11-16T23:59:59.000Z

    in show diets because of its rapid digestion and tendency to cause acido- sis (see the section on health). Oats are excellent for growth and development of steers or heifers. A mixture similar in nutrient content to oats can be formulated with a high...

  2. Probabilistic multiscale models and measurements of self-heating

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Probabilistic multiscale models and measurements of self-heating under multiaxial high cycle cyclic loadings, usually referred to as "self-heating tests." This paper focuses on two models whose parameters are tuned by resorting to self-heating tests and then used to predict high cycle fatigue

  3. Energy recovery system using an organic rankine cycle

    DOE Patents [OSTI]

    Ernst, Timothy C

    2013-10-01T23:59:59.000Z

    A thermodynamic system for waste heat recovery, using an organic rankine cycle is provided which employs a single organic heat transferring fluid to recover heat energy from two waste heat streams having differing waste heat temperatures. Separate high and low temperature boilers provide high and low pressure vapor streams that are routed into an integrated turbine assembly having dual turbines mounted on a common shaft. Each turbine is appropriately sized for the pressure ratio of each stream.

  4. An all-optical nanomechanical heat engine

    E-Print Network [OSTI]

    Andreas Dechant; Nikolai Kiesel; Eric Lutz

    2014-08-20T23:59:59.000Z

    We propose and theoretically investigate a nanomechanical heat engine. We show how a levitated nanoparticle in a harmonic optical trap inside an optical cavity can be used to realize a Stirling cycle in the underdamped regime. The all-optical approach enables fast and exible control of all the thermodynamical parameters and the effcient optimization of the performance of the engine. We develop a systematic optimization procedure to determine optimal driving protocols. We further perform numerical simulations with realistic parameters and evaluate the maximum power and the corresponding effciency.

  5. Cycle Track Lessons Learned

    E-Print Network [OSTI]

    Bertini, Robert L.

    Cycle Track Lessons Learned #12;Presentation Overview · Bicycling trends · Cycle track lessons learned · What is a "Cycle track"? · Essential design elements of cycle tracks Separation Width Crossing

  6. Method for processing LNG for rankine cycle

    SciTech Connect (OSTI)

    Aoki, I.; Matsumoto, O.

    1983-06-14T23:59:59.000Z

    A method is disclosed for processing lng using a mixed heat medium for performing a rankine cycle to gasify the lng. The medium is prepared by batch distillation using only lng. The method comprises the steps of condensing an upflow vapor in a single distillation column employing part of the lng in an lng batch distillation cycle, venting one fraction having low boiling point components mainly containing methane, and accumulating the other fractions containing ethane and components heavier than ethane. The supply of lng to be distilled in the column is halted. A total condensing operation is performed in which the other fractions are sequentially condensed by part of the lng at the condenser to sequentially recover and mix each component with the other fractions. Lng is added as the methane component to the recovered mixture of components to prepare a mixed heat medium consisting of components selected from hydrocarbons having 1-6 carbon atoms, or hydrocarbons having 1-6 carbon atoms and nitrogen. The mixed heat medium is stored. A mixed heat medium vapor generated by heat input to the stored mixed heat medium is condensed by lng and returned to the mixed heat medium; collection and complete gasification of the low boiling point components mainly containing methane and the lng is gasified by condensation to provide an lng vapor gas. Lng is gasified by performing the rankine cycle with the mixed heat medium.

  7. Combined rankine and vapor compression cycles

    DOE Patents [OSTI]

    Radcliff, Thomas D.; Biederman, Bruce P.; Brasz, Joost J.

    2005-04-19T23:59:59.000Z

    An organic rankine cycle system is combined with a vapor compression cycle system with the turbine generator of the organic rankine cycle generating the power necessary to operate the motor of the refrigerant compressor. The vapor compression cycle is applied with its evaporator cooling the inlet air into a gas turbine, and the organic rankine cycle is applied to receive heat from a gas turbine exhaust to heat its boiler within one embodiment, a common condenser is used for the organic rankine cycle and the vapor compression cycle, with a common refrigerant, R-245a being circulated within both systems. In another embodiment, the turbine driven generator has a common shaft connected to the compressor to thereby eliminate the need for a separate motor to drive the compressor. In another embodiment, an organic rankine cycle system is applied to an internal combustion engine to cool the fluids thereof, and the turbo charged air is cooled first by the organic rankine cycle system and then by an air conditioner prior to passing into the intake of the engine.

  8. Efficiency of Carnot Cycle with Arbitrary Gas Equation of State

    E-Print Network [OSTI]

    Paulus C. Tjiang; Sylvia H. Sutanto

    2006-03-27T23:59:59.000Z

    The derivation of the efficiency of Carnot cycle is usually done by calculating the heats involved in two isothermal processes and making use of the associated adiabatic relation for a given working substance's equation of state, usually the ideal gas. We present a derivation of Carnot efficiency using the same procedure with Redlich-Kwong gas as working substance to answer the calculation difficulties raised by Agrawal and Menon. We also show that using the same procedure, the Carnot efficiency may be derived regardless of the functional form of the gas equation of state.

  9. Induced natural convection thermal cycling device

    DOE Patents [OSTI]

    Heung, Leung Kit (Aiken, SC)

    2002-08-13T23:59:59.000Z

    A device for separating gases, especially isotopes, by thermal cycling of a separation column using a pressure vessel mounted vertically and having baffled sources for cold and heat. Coils at the top are cooled with a fluid such as liquid nitrogen. Coils at the bottom are either electrical resistance coils or a tubular heat exchange. The sources are shrouded with an insulated "top hat" and simultaneously opened and closed at the outlets to cool or heat the separation column. Alternatively, the sources for cold and heat are mounted separately outside the vessel and an external loop is provided for each circuit.

  10. Proceedings: Heat exchanger workshop

    SciTech Connect (OSTI)

    Not Available

    1987-07-01T23:59:59.000Z

    Heat transfer processes are of controlling importance in the operation of a thermal power plant. Heat exchangers are major cost items and are an important source of problems causing poor power plant availability and performance. A workshop to examine the improvements that can be made to heat exchangers was sponsored by the Electric Power Research Institute (EPRI) on June 10-11, 1986, in Palo Alto, California. This workshop was attended by 25 engineers and scientists representing EPRI-member utilities and EPRI consultants. A forum was provided for discussions related to the design, operation and maintenance of utility heat transfer equipment. The specific objectives were to identify research directions that could significantly improve heat exchanger performance, reliability and life cycle economics. Since there is a great diversity of utility heat transfer equipment in use, this workshop addressed two equipment categories: Boiler Feedwater Heaters (FWH) and Heat Recovery Steam Generators (HRSG). The workshop was divided into the following panel sessions: functional design, mechanical design, operation, suggested research topics, and prioritization. Each panel session began with short presentations by experts on the subject and followed by discussions by the attendees. This report documents the proceedings of the workshop and contains recommendations of potentially valuable areas of research and development. 4 figs.

  11. Thermodynamics -2 A cogeneration plant (plant which provides both electricity and thermal energy) executes a cycle

    E-Print Network [OSTI]

    Virginia Tech

    ) executes a cycle while receiving from a thermal reservoir at 900 K, supplying heat to a process at 400 K, rejecting heat to the environment at 325 K, and producing power. In the cycle shown, steam enters at P3 = 30 kPa. All components of the plant are well insulated, pressure drops in heat exchangers

  12. Investigating AGN Heating in a Sample of Nearby Clusters

    E-Print Network [OSTI]

    Dunn, R J H

    2006-01-01T23:59:59.000Z

    We analyse those objects in the Brightest 55 sample of clusters of galaxies which have a short central cooling time and a central temperature drop. Such clusters are likely to require some form of heating. Where clear radio bubbles are observed in these clusters, their energy injection is compared to the X-ray cooling rate. Of the 20 clusters requiring heating, at least 14 have clear bubbles, implying a duty cycle for the bubbling activity of at least 70 per cent. The average distance out to which the bubbles can offset the X-ray cooling, r_heat is given by r_heat/r_cool=0.86+/-0.11 where r_cool is defined as the radius as which the radiative cooling time is 3 Gyr. 10 out of 16 clusters have r_heat/r_cool>1, but there is a large range in values. The clusters which require heating but show no clear bubbles were combined with those clusters which have a radio core to form a second sub-sample. Using r_heat=0.86 r_cool we calculate the size of an average bubble expected in these clusters. In five cases (3C129.1, ...

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

    E-Print Network [OSTI]

    Norwood, Zachary Mills

    2011-01-01T23:59:59.000Z

    solar energy to provide the heat input to a Rankine cycle tosystem. This value, the heat input to the solar collector,generated. The heat and work inputs and outputs to the

  14. A statistical analysis of avalanching heat transport in stationary enhanced core confinement regimes

    SciTech Connect (OSTI)

    Tokunaga, S.; Jhang, Hogun; Kim, S. S. [WCI Center for Fusion Theory, National Fusion Research Institute, 52, Yeoeun-dong, Yusung-Gu, Daejon (Korea, Republic of); Diamond, P. H. [WCI Center for Fusion Theory, National Fusion Research Institute, 52, Yeoeun-dong, Yusung-Gu, Daejon (Korea, Republic of); Center for Astrophysics and Space Sciences and Department of Physics, University of California San Diego, La Jolla, California 92093-0429 (United States)

    2012-09-15T23:59:59.000Z

    We present a statistical analysis of heat transport in stationary enhanced confinement regimes obtained from flux-driven gyrofluid simulations. The probability density functions of heat flux in improved confinement regimes, characterized by the Nusselt number, show significant deviation from Gaussian, with a markedly fat tail, implying the existence of heat avalanches. Two types of avalanching transport are found to be relevant to stationary states, depending on the degree of turbulence suppression. In the weakly suppressed regime, heat avalanches occur in the form of quasi-periodic (QP) heat pulses. Collisional relaxation of zonal flow is likely to be the origin of these QP heat pulses. This phenomenon is similar to transient limit cycle oscillations observed prior to edge pedestal formation in recent experiments. On the other hand, a spectral analysis of heat flux in the strongly suppressed regime shows the emergence of a 1/f (f is the frequency) band, suggesting the presence of self-organized criticality (SOC)-like episodic heat avalanches. This episodic 1/f heat avalanches have a long temporal correlation and constitute the dominant transport process in this regime.

  15. Heat-pump-centered integrated community energy systems: system development summary

    SciTech Connect (OSTI)

    Calm, J.M.

    1980-02-01T23:59:59.000Z

    An introduction to district heating systems employing heat pumps to enable use of low-temperature energy sources is presented. These systems operate as thermal utilities to provide space heating and may also supply space cooling, service-water heating, and other thermal services. Otherwise-wasted heat from industrial and commercial processes, natural sources including solar and geothermal heat, and heat stored on an annual cycle from summer cooling may be effectively utilized by the systems described. These sources are abundant, and their use would conserve scarce resources and reduce adverse environmental impacts. More than one-quarter of the energy consumed in the United States is used to heat and cool buildings and to heat service water. Natural gas and oil provide approximately 83% of this energy. The systems described show potential to reduce net energy consumption for these services by 20 to 50% and to allow fuel substitution with less-scarce resources not practical in smaller, individual-building systems. Seven studies performed for the system development phase of the Department of Energy's Heat-Pump-Centered Integrated Community Energy Systems Project and to related studies are summarized. A concluding chapter tabulates data from these separately published studies.

  16. Validation of a PC based program for single stage absorption heat pump. Final report

    SciTech Connect (OSTI)

    Zaltash, A.; Ally, M.R.

    1991-09-01T23:59:59.000Z

    An interactive computer code was developed to evaluate single stage absorption heat pump performance for temperature amplifier and heat amplifier modes using water as the refrigerant. This program performs the cycle calculations for single stage cycles based on the polynomial expressions developed to correlate experimental vapor-liquid-equilibrium (VLE) and specific enthalpy-concentration data for LiBr/water and (Li, K, Na)NO{sub 3}/water systems as well as the properties of pure water. The operating parameters obtained by this program were tested against mass and energy balances in documented cases and the results show that the maximum deviation between coefficient of performance (COP) values obtained by this software and the ones previously calculated is less than 3%. In addition, this program was used to study the effect of solution temperature leaving the absorber on the other operating parameters. This type of analysis could be used to improve and optimize cycle design. 4 refs.

  17. Validation of a PC based program for single stage absorption heat pump

    SciTech Connect (OSTI)

    Zaltash, A.; Ally, M.R.

    1991-09-01T23:59:59.000Z

    An interactive computer code was developed to evaluate single stage absorption heat pump performance for temperature amplifier and heat amplifier modes using water as the refrigerant. This program performs the cycle calculations for single stage cycles based on the polynomial expressions developed to correlate experimental vapor-liquid-equilibrium (VLE) and specific enthalpy-concentration data for LiBr/water and (Li, K, Na)NO{sub 3}/water systems as well as the properties of pure water. The operating parameters obtained by this program were tested against mass and energy balances in documented cases and the results show that the maximum deviation between coefficient of performance (COP) values obtained by this software and the ones previously calculated is less than 3%. In addition, this program was used to study the effect of solution temperature leaving the absorber on the other operating parameters. This type of analysis could be used to improve and optimize cycle design. 4 refs.

  18. Fuel cycle cost uncertainty from nuclear fuel cycle comparison

    SciTech Connect (OSTI)

    Li, J.; McNelis, D. [Institute for the Environment, University of North Carolina, Chapel Hill (United States); Yim, M.S. [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology (Korea, Republic of)

    2013-07-01T23:59:59.000Z

    This paper examined the uncertainty in fuel cycle cost (FCC) calculation by considering both model and parameter uncertainty. Four different fuel cycle options were compared in the analysis including the once-through cycle (OT), the DUPIC cycle, the MOX cycle and a closed fuel cycle with fast reactors (FR). The model uncertainty was addressed by using three different FCC modeling approaches with and without the time value of money consideration. The relative ratios of FCC in comparison to OT did not change much by using different modeling approaches. This observation was consistent with the results of the sensitivity study for the discount rate. Two different sets of data with uncertainty range of unit costs were used to address the parameter uncertainty of the FCC calculation. The sensitivity study showed that the dominating contributor to the total variance of FCC is the uranium price. In general, the FCC of OT was found to be the lowest followed by FR, MOX, and DUPIC. But depending on the uranium price, the FR cycle was found to have lower FCC over OT. The reprocessing cost was also found to have a major impact on FCC.

  19. Advanced Organic Vapor Cycles for Improving Thermal Conversion Efficiency in Renewable Energy Systems

    E-Print Network [OSTI]

    Ho, Tony

    2012-01-01T23:59:59.000Z

    of low-grade heat," Renewable and Sustainable Energyof various applications," Renewable and Sustainable Energyorganic Rankine cycle," Renewable Energy, vol. 4, pp. 1196-

  20. Heat engine Device that transforms heat into work.

    E-Print Network [OSTI]

    Winokur, Michael

    , and rocket engines are heat engines. So are steam engines and turbines #12;2 refrigerator Device that uses the pV curve Steam turbines A steam turbine is a mechanical device that extracts thermal energy from by steam turbines. Steam turbines, jet engines and rocket engines use a Brayton cycle #12;4 Steam turbines

  1. 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...

  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* ... 1,602 1,397...

  3. 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...

  4. 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...

  5. 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...

  6. Absorption Cycle Fundamentals and Applications Guidelines for Distillation Energy Savings

    E-Print Network [OSTI]

    Erickson, D. C.; Davidson, W. F.

    1984-01-01T23:59:59.000Z

    The absorption cycle offers one of the most economic and widely applicable technologies for waste heat upgrading. It can use off-the-shelf hardware that is available now, at any required capacity rating. Fractional distillations, as a class...

  7. accelerated thermal cycle: Topics by E-print Network

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

    Rates of Some Candidate Rankine-Cycle Organic Working Fluids for Conversion of Industrial Waste Heat Into Power Texas A&M University - TxSpace Summary: investigation undertaken...

  8. assisting apprenticeship cycles: Topics by E-print Network

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

    all that apply New Hampshire, University of 16 Performance study on solar assisted heat pump water heater using CO2 in a transcritical cycle CiteSeer Summary: Abstract: This...

  9. assisted reproduction cycles: Topics by E-print Network

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

    is equipotent Paris-Sud XI, Universit de 25 Performance study on solar assisted heat pump water heater using CO2 in a transcritical cycle CiteSeer Summary: Abstract: This...

  10. absorption cycle cooling: Topics by E-print Network

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

    25 Next Page Last Page Topic Index 1 Life Cycle cost Analysis of Waste Heat Operated Absorption Cooling Systems for Building HVAC Applications Texas A&M University - TxSpace...

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

    SciTech Connect (OSTI)

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

    2012-07-01T23:59:59.000Z

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

  12. Supercritical CO2 direct cycle Gas Fast Reactor (SC-GFR) concept.

    SciTech Connect (OSTI)

    Wright, Steven Alan; Parma, Edward J., Jr.; Suo-Anttila, Ahti Jorma (Computational Engineering Analysis, Albuquerque, NM); Al Rashdan, Ahmad (Texas A& M University, College Station, TX); Tsvetkov, Pavel Valeryevich (Texas A& M University, College Station, TX); Vernon, Milton E.; Fleming, Darryn D.; Rochau, Gary Eugene

    2011-05-01T23:59:59.000Z

    This report describes the supercritical carbon dioxide (S-CO{sub 2}) direct cycle gas fast reactor (SC-GFR) concept. The SC-GFR reactor concept was developed to determine the feasibility of a right size reactor (RSR) type concept using S-CO{sub 2} as the working fluid in a direct cycle fast reactor. Scoping analyses were performed for a 200 to 400 MWth reactor and an S-CO{sub 2} Brayton cycle. Although a significant amount of work is still required, this type of reactor concept maintains some potentially significant advantages over ideal gas-cooled systems and liquid metal-cooled systems. The analyses presented in this report show that a relatively small long-life reactor core could be developed that maintains decay heat removal by natural circulation. The concept is based largely on the Advanced Gas Reactor (AGR) commercial power plants operated in the United Kingdom and other GFR concepts.

  13. Combined cycle power plant incorporating coal gasification

    DOE Patents [OSTI]

    Liljedahl, Gregory N. (Tariffville, CT); Moffat, Bruce K. (Simsbury, CT)

    1981-01-01T23:59:59.000Z

    A combined cycle power plant incorporating a coal gasifier as the energy source. The gases leaving the coal gasifier pass through a liquid couplant heat exchanger before being used to drive a gas turbine. The exhaust gases of the gas turbine are used to generate both high pressure and low pressure steam for driving a steam turbine, before being exhausted to the atmosphere.

  14. Carnot cycle for an oscillator

    E-Print Network [OSTI]

    Arnaud, J; Philippe, F

    2002-01-01T23:59:59.000Z

    Carnot established in 1824 that the efficiency of cyclic engines operating between a hot bath at absolute temperature Th and a cold bath at temperature Tc cannot exceed 1-Tc/Th. This result implies the existence of an entropy function S(U) with the property that d^2S/dU^2 less equal 0, where U denotes the average energy. Linear single-mode systems alternately in contact with hot and cold baths obey these principles. A specific expression of the work done per cycle by an oscillator is derived from a prescription established by Einstein in 1906: heat baths may exchange energy with oscillators at angular frequency omega only by amounts hbar *omega, where 2*pi*hbar denotes the Planck constant. Non-reversible cycles are illustrated. The paper is essentially self-contained.

  15. Heating system

    SciTech Connect (OSTI)

    Nishman, P.J.

    1983-03-08T23:59:59.000Z

    A heating system utilizing solar panels and buried ground conduits to collect and store heat which is delivered to a heatpump heat exchanger. A heat-distribution fluid continuously circulates through a ground circuit to transfer heat from the ground to the heat exchanger. The ground circuit includes a length of buried ground conduit, a pump, a check valve and the heat exchanger. A solar circuit, including a solar panel and a second pump, is connected in parallel with the check valve so that the distribution fluid transfers solar heat to the heat exchanger for utilization and to the ground conduit for storage when the second pump is energized. A thermostatically instrumented control system energizes the second pump only when the temperature differential between the solar panel inlet and outlet temperatures exceeds a predetermined value and the ground temperature is less than a predetermined value. Consequently, the distribution fluid flows through the solar panel only when the panel is capable of supplying significant heat to the remainder of the system without causing excessive drying of the ground.

  16. Simulation and performance analysis of basic GAX and advanced GAX cycles with ammonia/water and ammonia/water/LiBr absorption fluids

    SciTech Connect (OSTI)

    Zaltash, A.; Grossman, G.

    1996-03-01T23:59:59.000Z

    The generator-absorber heat exchange (GAX) and branched GAX cycles are generally considered with NH{sub 3}/H{sub 2}O as their working fluid. The potential consequences of using a ternary mixture of NH{sub 3}/H{sub 2}O/LiBr (advanced fluids) in the GAX and Branched GAX (advanced cycles) are discussed in this study. A modular steady state absorption simulation model(ABSIM) was used to investigate the potential of combining the above advanced cycles with the advanced fluids. ABSIM is capable of modeling varying cycle configurations with different working fluids. Performance parameters of the cycles, including coefficient of performance (COP) and heat duties, were investigated as functions of different operating parameters in the cooling mode for both the NH {sub 3}/H{sub 2}O binary and the NH{sub 3}/H{sub 2}O/LiBr ternary mixtures. High performance potential of GAX and branched GAX cycles using the NH{sub 3}/H{sub 2}O/LiBr ternary fluid mixture was achieved especially at the high range of firing temperatures exceeding 400{degrees}F. The cooling COP`s have been improved by approximately 21% over the COP achieved with the NH{sub 3}/H{sub 2}O binary mixtures. These results show the potential of using advanced cycles with advanced fluid mixtures (ternary or quaternary fluid mixtures).

  17. A Coupled Quantum Otto Cycle

    E-Print Network [OSTI]

    George Thomas; Ramandeep S. Johal

    2010-11-03T23:59:59.000Z

    We study the 1-d isotropic Heisenberg model of two spin-1/2 systems as a quantum heat engine. The engine undergoes a four-step Otto cycle where the two adiabatic branches involve changing the external magnetic field at a fixed value of the coupling constant. We find conditions for the engine efficiency to be higher than the uncoupled model; in particular, we find an upper bound which is tighter than the Carnot bound. A new domain of parameter values is pointed out which was not feasible in the interaction-free model. Locally, each spin seems to effect the flow of heat in a direction opposite to the global temperature gradient. This seeming contradiction to the second law can be resolved in terms of local effective temperature of the spins.

  18. Study on the heat transfer of heat exchangers for the Stirling Engine

    SciTech Connect (OSTI)

    Kanzaka, M. (Nagasaki Research and Development Center (JP)); Iwabuchi, M. (Advanced Technology Research Center, Mitsubishi Heavy Industries, Ltd. (JP))

    1991-01-01T23:59:59.000Z

    This paper reports that heat-transfer characteristics in heated tubes under periodically reversing flow conditions have been investigated experimentally using a test apparatus that simulates the heat exchangers for the actual Sterling engine. It was shown that the heat-transfer characteristics under these conditions were greatly affected by the piston phase-angle difference that generates the reversing flow of the working gas, and this phenomenon was proper to the heat transfer under the periodically reversing flow and was different from conventional heat transfer in steady flow. The experimental correlation considering the influence of the piston phase-angle difference for the heat-transfer coefficient has been induced by the use of the working gas velocity evaluated from the Schmidt cycle model which is one of the ideal Sterling cycles.

  19. Proceedings: Sixth International Conference on Fossil Plant Cycle Chemistry

    SciTech Connect (OSTI)

    None

    2001-04-01T23:59:59.000Z

    The purity of boiler water, feedwater, and steam is central to ensuring component availability and reliability in fossil-fired plants. These conference proceedings address the state of the art in fossil plant and combined cycle/heat recovery steam generator (HRSG) cycle chemistry as well as international practices for control of corrosion and water preparation and purification.

  20. Hybrid solar central receiver for combined cycle power plant

    DOE Patents [OSTI]

    Bharathan, Desikan (Lakewood, CO); Bohn, Mark S. (Golden, CO); Williams, Thomas A. (Arvada, CO)

    1995-01-01T23:59:59.000Z

    A hybrid combined cycle power plant including a solar central receiver for receiving solar radiation and converting it to thermal energy. The power plant includes a molten salt heat transfer medium for transferring the thermal energy to an air heater. The air heater uses the thermal energy to preheat the air from the compressor of the gas cycle. The exhaust gases from the gas cycle are directed to a steam turbine for additional energy production.

  1. Hybrid solar central receiver for combined cycle power plant

    DOE Patents [OSTI]

    Bharathan, D.; Bohn, M.S.; Williams, T.A.

    1995-05-23T23:59:59.000Z

    A hybrid combined cycle power plant is described including a solar central receiver for receiving solar radiation and converting it to thermal energy. The power plant includes a molten salt heat transfer medium for transferring the thermal energy to an air heater. The air heater uses the thermal energy to preheat the air from the compressor of the gas cycle. The exhaust gases from the gas cycle are directed to a steam turbine for additional energy production. 1 figure.

  2. Sorption heat engines: simple inanimate negative entropy generators

    E-Print Network [OSTI]

    Anthonie W. J. Muller; Dirk Schulze-Makuch

    2005-12-18T23:59:59.000Z

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

  3. Reproducibility of High-Q SRF Cavities by High Temperature Heat Treatment

    SciTech Connect (OSTI)

    Dhakal, Pashupati [JLAB; Ciovati, Gianluigi [JLAB; Kneisel, Peter [JLAB; Myneni, Ganapati Rao [JLAB

    2014-07-01T23:59:59.000Z

    Recent work on high-temperature (> 600 °C) heat treatment of ingot Nb cavities in a customized vacuum furnace for several hours showed the possibility of achieving Q0-values of up to ~5×1010 at 2.0 K, 1.5 GHz and accelerating gradients of ~20 MV/m. This contribution presents results on further studies of the heat treatment process to produce cavities with high Q0 values for continuous-wave accelerator application. Single-cell cavities of different Nb purity have been processed through few cycles of heat-treatments and chemical etching. Measurements of Q0 as a function of temperature at low RF field and of Q0 as a function of the RF field at or below 2.0 K have been made after each treatment. Measurements by TOF-SIMS of the impurities? depth profiles were made on samples heat treated with the cavities.

  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.

    2013-09-01T23:59:59.000Z

    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. Combined Cycles and Cogeneration - An Alternative for the Process Industries 

    E-Print Network [OSTI]

    Harkins, H. L.

    1981-01-01T23:59:59.000Z

    -of-the-art combined cycle system consisting of combustion turbines, heat recovery steam generators, and steam turbine-generator units, offers a high efficiency method for the production of electrical and heat energy at relatively low installed and operating costs...

  6. Novel Power Cycle for Combined-Cycle Systems and Utility Power Plants

    E-Print Network [OSTI]

    Kalina, A. L.

    for the advanced gas turbine 700lF, manufactured by the General Electric Company. According to data provided by EPRI, the most advanced Rankine bottoming cycle, with a double pressure boiler and reheating, can produce, using the heat exhaust of this turbine..., 169.2 megawatts. If a triple pressure Rankine Cycle is used as a bottoming cycle, the gross output can reach, according to EPRI, 182.6 MW. This performance has been taken as a baseline for comparison with the performance of System 6, which has...

  7. Functional groups show distinct differences in nitrogen cycling during early stand development: implications for forest management.

    SciTech Connect (OSTI)

    Aubrey, Doug, P.; Coyle, David, R. Coleman, Mark, D.

    2011-08-26T23:59:59.000Z

    Nutrient acquisition of forest stands is controlled by soil resource availability and belowground production, but tree species are rarely compared in this regard. Here, we examine ecological and management implications of nitrogen (N) dynamics during early forest stand development in productive commercial tree species with narrow (Populus deltoides Bartr. and Platanus occidentalis L.) and broad (Liquidambar styraciflua L. and Pinus taeda L.) site requirements while grown with a range of nutrient and water resources. We constructed N budgets by measuring N concentration ([N]) and N content (N{sub C}) of above- and belowground perennial and ephemeral tissues, determined N uptake (N{sub UP}), and calculated N use efficiency (NUE). Forest stands regulated [N] within species-specific operating ranges without clear temporal or treatment patterns, thus demonstrating equilibrium between tissue [N] and biomass accumulation. Forest stand N{sub C} and N{sub UP} increased with stand development and paralleled treatment patterns of biomass accumulation, suggesting productivity is tightly linked to N{sub UP}. Inclusion of above- and belowground ephemeral tissue turnover in N{sub UP} calculations demonstrated that maximum N demand for narrow-sites adapted species exceeded 200 kg N ha{sup -1} year{sup -1} while demand for broad-site adapted species was below this level. NUE was species dependent but not consistently influenced by N availability, suggesting relationships between NUE and resource availability were species dependent. Based on early stand development, species with broad site adaptability are favored for woody cropping systems because they maintain high above- and belowground productivity with minimal fertilization requirements due to higher NUE than narrow site adapted species.

  8. Lecture Ch. 2a Energy and heat capacity

    E-Print Network [OSTI]

    Russell, Lynn

    machine! Conservation of energy! Definition of energy! Uniqueness of work values! Q = 0,W = 0 ! "E = 0 ! E1 Lecture Ch. 2a · Energy and heat capacity ­ State functions or exact differentials ­ Internal energy vs. enthalpy · 1st Law of thermodynamics ­ Relate heat, work, energy · Heat/work cycles (and path

  9. Lecture Ch. 2a Energy and heat capacity

    E-Print Network [OSTI]

    Russell, Lynn

    of energy Definition of energy Uniqueness of work values Q = 0,W = 0 E = 0 E2 = E1 Q = 0 E = W Wrev1 Lecture Ch. 2a · Energy and heat capacity ­ State functions or exact differentials ­ Internal energy vs. enthalpy · 1st Law of thermodynamics ­ Relate heat, work, energy · Heat/work cycles (and path

  10. Power systems utilizing the heat of produced formation fluid

    DOE Patents [OSTI]

    Lambirth, Gene Richard (Houston, TX)

    2011-01-11T23:59:59.000Z

    Systems, methods, and heaters for treating a subsurface formation are described herein. At least one method includes treating a hydrocarbon containing formation. The method may include providing heat to the formation; producing heated fluid from the formation; and generating electricity from at least a portion of the heated fluid using a Kalina cycle.

  11. Development of the household sample for furnace and boilerlife-cycle cost analysis

    SciTech Connect (OSTI)

    Whitehead, Camilla Dunham; Franco, Victor; Lekov, Alex; Lutz, Jim

    2005-05-31T23:59:59.000Z

    Residential household space heating energy use comprises close to half of all residential energy consumption. Currently, average space heating use by household is 43.9 Mbtu for a year. An average, however, does not reflect regional variation in heating practices, energy costs, or fuel type. Indeed, a national average does not capture regional or consumer group cost impacts from changing efficiency levels of heating equipment. The US Department of Energy sets energy standards for residential appliances in, what is called, a rulemaking process. The residential furnace and boiler efficiency rulemaking process investigates the costs and benefits of possible updates to the current minimum efficiency regulations. Lawrence Berkeley National Laboratory (LBNL) selected the sample used in the residential furnace and boiler efficiency rulemaking from publically available data representing United States residences. The sample represents 107 million households in the country. The data sample provides the household energy consumption and energy price inputs to the life-cycle cost analysis segment of the furnace and boiler rulemaking. This paper describes the choice of criteria to select the sample of houses used in the rulemaking process. The process of data extraction is detailed in the appendices and is easily duplicated. The life-cycle cost is calculated in two ways with a household marginal energy price and a national average energy price. The LCC results show that using an national average energy price produces higher LCC savings but does not reflect regional differences in energy price.

  12. COMPARATIVE STUDY AMONG HYBRID GROUND SOURCE HEAT PUMP SYSTEM, COMPLETE GROUND SOURCE HEAT PUMP AND CONVENTIONAL HVAC SYSTEM

    SciTech Connect (OSTI)

    Jiang Zhu; Yong X. Tao

    2011-11-01T23:59:59.000Z

    In this paper, a hotel with hybrid geothermal heat pump system (HyGSHP) in the Pensacola is selected and simulated by the transient simulation software package TRNSYS [1]. To verify the simulation results, the validations are conducted by using the monthly average entering water temperature, monthly facility consumption data, and etc. And three types of HVAC systems are compared based on the same building model and HVAC system capacity. The results are presented to show the advantages and disadvantages of HyGSHP compared with the other two systems in terms of energy consumptions, life cycle cost analysis.

  13. Edgeworth cycles revisited

    E-Print Network [OSTI]

    Doyle, Joseph J.

    Some gasoline markets exhibit remarkable price cycles, where price spikes are followed by a series of small price declines: a pattern consistent with a model of Edgeworth cycles described by Maskin and Tirole. We extend ...

  14. The Carnot efficiencybetween these temperatures is: This provides an absolute upper limit to the Rankine cycle effi-

    E-Print Network [OSTI]

    Liu, Y. A.

    to the Rankine cycle effi- ciency. Heat Absorbed from Stream 3 Power Produced by Steam Turbine Required Power a steam cycle alongsidethe gas turbine cycle. LITERATURE CITED Christodoulou,K., Diploma Thesis, N Output of Gas Turbine For the Gas Turbine Cycle Calculated for Case 2, Upper Exhaust Temperature T6

  15. Pipeline bottoming cycle study. Final report

    SciTech Connect (OSTI)

    Not Available

    1980-06-01T23:59:59.000Z

    The technical and economic feasibility of applying bottoming cycles to the prime movers that drive the compressors of natural gas pipelines was studied. These bottoming cycles convert some of the waste heat from the exhaust gas of the prime movers into shaft power and conserve gas. Three typical compressor station sites were selected, each on a different pipeline. Although the prime movers were different, they were similar enough in exhaust gas flow rate and temperature that a single bottoming cycle system could be designed, with some modifications, for all three sites. Preliminary design included selection of the bottoming cycle working fluid, optimization of the cycle, and design of the components, such as turbine, vapor generator and condensers. Installation drawings were made and hardware and installation costs were estimated. The results of the economic assessment of retrofitting bottoming cycle systems on the three selected sites indicated that profitability was strongly dependent upon the site-specific installation costs, how the energy was used and the yearly utilization of the apparatus. The study indicated that the bottoming cycles are a competitive investment alternative for certain applications for the pipeline industry. Bottoming cycles are technically feasible. It was concluded that proper design and operating practices would reduce the environmental and safety hazards to acceptable levels. The amount of gas that could be saved through the year 2000 by the adoption of bottoming cycles for two different supply projections was estimated as from 0.296 trillion ft/sup 3/ for a low supply projection to 0.734 trillion ft/sup 3/ for a high supply projection. The potential market for bottoming cycle equipment for the two supply projections varied from 170 to 500 units of varying size. Finally, a demonstration program plan was developed.

  16. Corrosive resistant heat exchanger

    DOE Patents [OSTI]

    Richlen, Scott L. (Annandale, VA)

    1989-01-01T23:59:59.000Z

    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.

  17. Heat collector

    DOE Patents [OSTI]

    Merrigan, Michael A. (Santa Cruz, NM)

    1984-01-01T23:59:59.000Z

    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.

  18. Heat collector

    DOE Patents [OSTI]

    Merrigan, M.A.

    1981-06-29T23:59:59.000Z

    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.

  19. M. Bahrami ENSC 461 (S 11) Vapor Power Cycles 1 Vapor Power Cycles

    E-Print Network [OSTI]

    Bahrami, Majid

    is not a suitable model for steam power cycle since: The turbine has to handle steam with low quality which will cause erosion and wear in turbine blades. It is impractical to design a compressor that handles two vapor expands isentropically in turbine and produces work. 4-1: Const P heat rejection High quality

  20. Magnetically driven quantum heat engine

    E-Print Network [OSTI]

    Enrique Muñoz; Francisco J. Peña

    2014-05-12T23:59:59.000Z

    We studied the efficiency of two different schemes for a magnetically driven quantum heat engine, by considering as the working substance a single nonrelativistic particle trapped in a cylindrical potential well, in the presence of an external magnetic field. The first scheme is a cycle, composed of two adiabatic and two isoenergetic reversible trajectories in configuration space. The trajectories are driven by a quasistatic modulation of the external magnetic-field intensity. The second scheme is a variant of the former, where the isoenergetic trajectories are replaced by isothermal ones, along which the system is in contact with macroscopic thermostats. This second scheme constitutes a quantum analog of the classical Carnot cycle.

  1. Current Comparison of Advanced Fuel Cycle Options

    SciTech Connect (OSTI)

    Steven J. Piet; B. W. Dixon; A. Goldmann; R. N. Hill; J. J. Jacobson; G. E. Matthern; J. D. Smith; A. M. Yacout

    2006-03-01T23:59:59.000Z

    The nuclear fuel cycle includes mining, enrichment, nuclear power plants, recycling (if done), and residual waste disposition. The U.S. Advanced Fuel Cycle Initiative (AFCI) has four program objectives to guide research on how best to glue these pieces together, as follows: waste management, proliferation resistance, energy recovery, and systematic management/economics/safety. We have developed a comprehensive set of metrics to evaluate fuel cycle options against the four program objectives. The current list of metrics is long-term heat, long-term dose, radiotoxicity and weapons usable material. This paper describes the current metrics and initial results from comparisons made using these metrics. The data presented were developed using a combination of “static” calculations and a system dynamic model, DYMOND. In many cases, we examine the same issue both dynamically and statically to determine the robustness of the observations. All analyses are for the U.S. reactor fleet. This work aims to clarify many of the issues being discussed within the AFCI program, including Inert Matrix Fuel (IMF) versus Mixed Oxide (MOX) fuel, single-pass versus multi-pass recycling, thermal versus fast reactors, and the value of separating cesium and strontium. The results from a series of dynamic simulations evaluating these options are included in this report. The model interface includes a few “control knobs” for flying or piloting the fuel cycle system into the future. The results from the simulations show that the future is dark (uncertain) and that the system is sluggish with slow time response times to changes (i.e., what types of reactors are built, what types of fuels are used, and the capacity of separation and fabrication plants). Piloting responsibilities are distributed among utilities, government, and regulators, compounding the challenge of making the entire system work and respond to changing circumstances. We identify four approaches that would increase our chances of a sustainable fuel cycle system: (1) have a recycle strategy that could be implemented before the 2030-2050 approximate period when current reactors retire so that replacement reactors fit into the strategy, (2) establish an option such as multi-pass blended-core IMF as a downward Pu control knob and accumulate waste management benefits early, (3) establish fast reactors with flexible conversion ratio as a future control knob that slowly becomes available if/when fast reactors are added to the fleet, and (4) expand exploration of heterogeneous assemblies and cores, which appear to have advantages such as increased agility. Initial results suggest multi-pass full-core MOX appears to be a less effective way than multi-pass blended core IMF to manage the fuel cycle system because it requires higher TRU throughput while accruing waste management benefits at a slower rate. Single-pass recycle approaches for LWRs do not meet AFCI program objectives and could be considered a “dead end.” We did not study the Very High Temperature Reactor (VHTR). Fast reactors appear to be effective options but a significant number of fast reactors must be deployed before the benefit of such strategies can be observed.

  2. EVALUATION OF A SULFUR OXIDE CHEMICAL HEAT STORAGE PROCESS FOR A STEAM SOLAR ELECTRIC PLANT

    E-Print Network [OSTI]

    Dayan, J.

    2011-01-01T23:59:59.000Z

    Flows and stream conditions in steam power cycle. Table 4.1in the low-temperature reactor system. Steam power cycle 8.1Heat Storage System for a Solar Steam Power Plant." 12th

  3. High efficiency carbonate fuel cell/turbine hybrid power cycle

    SciTech Connect (OSTI)

    Steinfeld, G.; Maru, H.C. [Energy Research Corp., Danbury, CT (United States); Sanderson, R.A. [Sanderson (Robert) and Associates, Wethersfield, CT (United States)

    1996-07-01T23:59:59.000Z

    The hybrid power cycle studies were conducted to identify a high efficiency, economically competitive system. A hybrid power cycle which generates power at an LHV efficiency > 70% was identified that includes an atmospheric pressure direct carbonate fuel cell, a gas turbine, and a steam cycle. In this cycle, natural gas fuel is mixed with recycled fuel cell anode exhaust, providing water for reforming fuel. The mixed gas then flows to a direct carbonate fuel cell which generates about 70% of the power. The portion of the anode exhaust which is not recycled is burned and heat transferred through a heat exchanger (HX) to the compressed air from a gas turbine. The heated compressed air is then heated further in the gas turbine burner and expands through the turbine generating 15% of the power. Half the exhaust from the turbine provides air for the anode exhaust burner. All of the turbine exhaust eventually flows through the fuel cell cathodes providing the O2 and CO2 needed in the electrochemical reaction. Exhaust from the cathodes flows to a steam system (heat recovery steam generator, staged steam turbine generating 15% of the cycle power). Simulation of a 200 MW plant with a hybrid power cycle had an LHV efficiency of 72.6%. Power output and efficiency are insensitive to ambient temperature, compared to a gas turbine combined cycle; NOx emissions are 75% lower. Estimated cost of electricity for 200 MW is 46 mills/kWh, which is competitive with combined cycle where fuel cost is > $5.8/MMBTU. Key requirement is HX; in the 200 MW plant studies, a HX operating at 1094 C using high temperature HX technology currently under development by METC for coal gassifiers was assumed. A study of a near term (20 MW) high efficiency direct carbonate fuel cell/turbine hybrid power cycle has also been completed.

  4. Cycle to Cycle Manufacturing Process Control

    E-Print Network [OSTI]

    Hardt, David E.

    Most manufacturing processes produce parts that can only be correctly measured after the process cycle has been completed. Even if in-process measurement and control is possible, it is often too expensive or complex to ...

  5. 11-14 An ideal vapor-compression refrigeration cycle with refrigerant-134a as the working fluid is considered. The rate of heat removal from the refrigerated space, the power input to the compressor, the rate of heat rejection to the environment,

    E-Print Network [OSTI]

    Kostic, Milivoje M.

    to the compressor, the rate of heat rejection to the environment, and the COP are to be determined. Assumptions 1 enters the compressor as a saturated vapor at the evaporator pressure, and leaves the condenser space and the power input to the compressor are determined from s and ( ) ( )( ) ( ) ( )( ) kW1.83 kW7

  6. New Regenerative Cycle for Vapor Compression Refrigeration

    SciTech Connect (OSTI)

    Bergander, Mark J [Magnetic Development, Inc.; Butrymowicz, Dariusz [Polish Academy of Scinces

    2010-01-26T23:59:59.000Z

    This project was a continuation of Category 1 project, completed in August 2005. Following the successful bench model demonstration of the technical feasibility and economic viability, the main objective in this stage was to fabricate the prototype of the heat pump, working on the new thermodynamic cycle. This required further research to increase the system efficiency to the level consistent with theoretical analysis of the cycle. Another group of objectives was to provide the foundation for commercialization and included documentation of the manufacturing process, preparing the business plan, organizing sales network and raising the private capital necessary to acquire production facilities.

  7. Split stream boilers for high-temperature/high-pressure topping steam turbine combined cycles

    SciTech Connect (OSTI)

    Rice, I.G. [Rice (I.G.), Spring, TX (United States)

    1997-04-01T23:59:59.000Z

    Research and development work on high-temperature and high-pressure (up to 1,500 F TIT and 4,500 psia) topping steam turbines and associated steam generators for steam power plants as well as combined cycle plants is being carried forward by DOE, EPRI, and independent companies. Aeroderivative gas turbines and heavy-duty gas turbines both will require exhaust gas supplementary firing to achieve high throttle temperatures. This paper presents an analysis and examples of a split stream boiler arrangement for high-temperature and high-pressure topping steam turbine combined cycles. A portion of the gas turbine exhaust flow is run in parallel with a conventional heat recovery steam generator (HRSG). This side stream is supplementary fired opposed to the current practice of full exhaust flow firing. Chemical fuel gas recuperation can be incorporated in the side stream as an option. A significant combined cycle efficiency gain of 2 to 4 percentage points can be realized using this split stream approach. Calculations and graphs show how the DOE goal of 60 percent combined cycle efficiency burning natural gas fuel can be exceeded. The boiler concept is equally applicable to the integrated coal gas fuel combined cycle (IGCC).

  8. RC-1 organic Rankine bottoming cycle for an adiabatic diesel engine. Final report

    SciTech Connect (OSTI)

    DiNanno, L.R.; DiBella, F.A.; Koplow, M.D.

    1983-12-01T23:59:59.000Z

    A system analysis and preliminary design were conducted for an organic Rankine-cycle system to bottom the high-temperature waste heat of an adiabatic diesel engine. The bottoming cycle is a compact package that includes a cylindrical air-cooled condenser-regenerator module and other unique features. The bottoming cycle output is 56 horsepower at design point conditions when compounding the reference 317 horsepower turbocharged (TC) diesel engine with a resulting brake specific fuel consumption of 0.268 lb/hp-hr for the compound engine. The bottoming cycle when applied to a turbocompound (TCPD) diesel delivers a compound engine brake specific fuel consumption of 0.258 lb/hp-hr. This system for heavy-duty trnsport applications uses the organic working fluid RC-1, which is a mixture of 60 mole percent pentafluorobenzene (PFB) and 40 mole percent hexafluorobenzene (HFB). Included in these 1983 work efforts was the thermal stability testing of the RC-1 organic fluid in a dynamic fluid test loop that simulates the operation of Rankine-cycle. More than 1600 hours of operation were completed with results showing that the RC-1 is thermally stable up to 900/sup 0/F. This report describes the work performed for one of the multiple contracts awarded under the Department of Energy's Heavy-Duty Transport Technology Program.

  9. CONTROL DESIGN FOR A GAS TURBINE CYCLE WITH CO2 CAPTURE CAPABILITIES

    E-Print Network [OSTI]

    Foss, Bjarne A.

    . The exhaust gas from a gas turbine with CO2 as working fluid, is used as heating medium for a steam cycleCONTROL DESIGN FOR A GAS TURBINE CYCLE WITH CO2 CAPTURE CAPABILITIES Dagfinn Snarheim Lars Imsland. of Science and Technology, 7491 Trondheim Abstract: The semi-closed oxy-fuel gas turbine cycle has been

  10. Method and apparatus for fuel gas moisturization and heating

    DOE Patents [OSTI]

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

    2002-01-01T23:59:59.000Z

    Fuel gas is saturated with water heated with a heat recovery steam generator heat source. The heat source is preferably a water heating section downstream of the lower pressure evaporator to provide better temperature matching between the hot and cold heat exchange streams in that portion of the heat recovery steam generator. The increased gas mass flow due to the addition of moisture results in increased power output from the gas and steam turbines. Fuel gas saturation is followed by superheating the fuel, preferably with bottom cycle heat sources, resulting in a larger thermal efficiency gain compared to current fuel heating methods. There is a gain in power output compared to no fuel heating, even when heating the fuel to above the LP steam temperature.

  11. Heating Rate Profiles in Galaxy Clusters

    E-Print Network [OSTI]

    Edward C. D. Pope; Georgi Pavlovski; Christian R. Kaiser; Hans Fangohr

    2006-01-05T23:59:59.000Z

    In recent years evidence has accumulated suggesting that the gas in galaxy clusters is heated by non-gravitational processes. Here we calculate the heating rates required to maintain a physically motived mass flow rate, in a sample of seven galaxy clusters. We employ the spectroscopic mass deposition rates as an observational input along with temperature and density data for each cluster. On energetic grounds we find that thermal conduction could provide the necessary heating for A2199, Perseus, A1795 and A478. However, the suppression factor, of the clasical Spitzer value, is a different function of radius for each cluster. Based on the observations of plasma bubbles we also calculate the duty cycles for each AGN, in the absence of thermal conduction, which can provide the required energy input. With the exception of Hydra-A it appears that each of the other AGNs in our sample require duty cycles of roughly $10^{6}-10^{7}$ yrs to provide their steady-state heating requirements. If these duty cycles are unrealistic, this may imply that many galaxy clusters must be heated by very powerful Hydra-A type events interspersed between more frequent smaller-scale outbursts. The suppression factors for the thermal conductivity required for combined heating by AGN and thermal conduction are generally acceptable. However, these suppression factors still require `fine-tuning` of the thermal conductivity as a function of radius. As a consequence of this work we present the AGN duty cycle as a cooling flow diagnostic.

  12. A testing and HVAC design methodology for air-to-air heat pipe heat exchangers

    SciTech Connect (OSTI)

    Guo, P.; Ciepliski, D.L.; Besant, R.W. [Univ. of Saskatchewan, Saskatoon, Saskatchewan (Canada). Dept. of Mechanical Engineering

    1998-10-01T23:59:59.000Z

    Air-to-air heat pipe heat exchangers were tested using ASHRAE Standard 84-1991 as a guide. Some changes are introduced for the test facility and methods of calculating effectiveness. ASME PTC 19.1-1985 is used as a guide for uncertainty analysis. Tests were done for a range of mass flux [1.574 to 2.912 kg/(m{sup 2}{center_dot}s)], ratios of mass flow rates (0.6 to 1.85), supply air temperatures ({minus}10 C to 40 C), and heat exchanger tilt angles ({minus}8.9{degree} to 11.2{degree}). Because humidity changes in the exhaust and supply air streams were negligible, only the effectiveness of sensible and of total energy was considered. Measured and calculated results show significant variations in the effectiveness of sensible and of total energy, and uncertainties with each independent variable. For balanced exhaust and supply flow rates at {minus}10 C supply air temperature and 1.574 kg/(m{sup 2}{center_dot}s) mass flux, the measured effectiveness for sensible and total energy was calculated to be 0.48 and 0.44, respectively, with uncertainties of 0.057 and 0.052. These measurements decreased to 0.42 and 0.37, with uncertainties of 0.016 and 0.018 for a mass flux of 2.912 kg/(m{sup 2}{center_dot}s). Because water vapor condensation effects were small or negligible, the difference between the effectiveness for the sensible and total energy was within the overlapping uncertainty range of each. Based on counterflow heat exchanger theory and convective heat transfer equations, expressions are presented to extrapolate the effectiveness data between and beyond the measured data points. These effectiveness equations, which represent the variation in effectiveness with several independent operating variables, are used for HVAC design that is aimed at achieving minimum life-cycle costs.

  13. Menstrual cycle effects on spatial location tasks

    E-Print Network [OSTI]

    Andrew, Sarah

    2013-02-22T23:59:59.000Z

    The relationship between menstrual cycle hormones and performance on gender-linked spatial tasks was examined in college women. Healthy women and men over the age of 18 and not taking hormonal preparations completed tasks that typically show a male...

  14. Waste Heat-to-Power in Small Scale Industry Using Scroll Expander...

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

    in Small Scale Industry Using Scroll Expander for Organic Rankine Bottoming Cycle Waste Heat-to-Power in Small Scale Industry Using Scroll Expander for Organic Rankine...

  15. Waste heat driven absorption refrigeration process and system

    DOE Patents [OSTI]

    Wilkinson, William H. (Columbus, OH)

    1982-01-01T23:59:59.000Z

    Absorption cycle refrigeration processes and systems are provided which are driven by the sensible waste heat available from industrial processes and other sources. Systems are disclosed which provide a chilled water output which can be used for comfort conditioning or the like which utilize heat from sensible waste heat sources at temperatures of less than 170.degree. F. Countercurrent flow equipment is also provided to increase the efficiency of the systems and increase the utilization of available heat.

  16. Process Integration of Industrial Heat Pumps 

    E-Print Network [OSTI]

    Priebe, S. J.; Chappell, R. N.

    1986-01-01T23:59:59.000Z

    The integration of heat pumps into industrial processes shows potential for energy savings. Heat pumps must, however, be integrated properly relative to the process pinch and the unit operations in the process. The shape of the grand composite curve...

  17. 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 */ livingPattern : Room ­? behaviour; setTemp : Room ­? num; heatSwitchOn, heatSwitchOff, userReset : simple

  18. Transportation implications of a closed fuel cycle.

    SciTech Connect (OSTI)

    Bullard, Tim (University of Nevada - Reno); Bays, Samuel (Idaho National Laboratory); Dennis, Matthew L.; Weiner, Ruth F.; Sorenson, Ken Bryce; Dixon, Brent (Idaho National Laboratory); Greiner, Miles (University of Nevada - Reno)

    2010-10-01T23:59:59.000Z

    Transportation for each step of a closed fuel cycle is analyzed in consideration of the availability of appropriate transportation infrastructure. The United States has both experience and certified casks for transportation that may be required by this cycle, except for the transport of fresh and used MOX fuel and fresh and used Advanced Burner Reactor (ABR) fuel. Packaging that had been used for other fuel with somewhat similar characteristics may be appropriate for these fuels, but would be inefficient. Therefore, the required neutron and gamma shielding, heat dissipation, and criticality were calculated for MOX and ABR fresh and spent fuel. Criticality would not be an issue, but the packaging design would need to balance neutron shielding and regulatory heat dissipation requirements.

  19. Design and performance of a new induction furnace for heat treatment of superconducting radiofrequency niobium cavities

    SciTech Connect (OSTI)

    Pashupati Dhakal, Gianluigi Ciovati, Wayne Rigby, John Wallace, Ganapati Rao Myneni

    2012-06-01T23:59:59.000Z

    Superconducting radio frequency (SRF) cavities made of high purity niobium (Nb) are the building blocks of many modern particle accelerators. The fabrication process includes several cycles of chemical and heat treatment at low ({approx}120 deg C) and high ({approx}800 deg C) temperatures. In this contribution, we describe the design and performance of an ultra-high-vacuum furnace which uses an induction heating system to heat treat SRF cavities. Cavities are heated by radiation from the Nb susceptor. By using an all-niobium hot zone, contamination of the Nb cavity by foreign elements during heat treatment is minimized and allows avoiding subsequent chemical etching. The furnace was operated up to 1400 deg C with a maximum pressure of {approx}1 x 10{sup -5} Torr and the maximum achievable temperature is estimated to be higher than 2000 deg C. Initial results on the performance of a single cell 1.5 GHz cavity made of ingot Nb heat treated at 1200 deg C using this new induction furnace and without subsequent chemical etching showed a reduction of the RF losses by a factor of {approx}2 compared to cavities made of fine-grain Nb which underwent standard chemical and heat treatments.

  20. Design and performance of a new induction furnace for heat treatment of superconducting radiofrequency niobium cavities

    SciTech Connect (OSTI)

    Dhakal, Pashupati; Ciovati, Gianluigi; Myneni, Ganapati Rao [Jefferson Lab, Newport News, Virginia 23606 (United States); Rigby, Wayne [Specialty Vacuum, Placitas, New Mexico 87043 (United States); Wallace, John [Casting Analysis Corporation, Weyers Cave, Virginia 24468 (United States)

    2012-06-15T23:59:59.000Z

    Superconducting radio frequency (SRF) cavities made of high purity niobium (Nb) are the building blocks of many modern particle accelerators. The fabrication process includes several cycles of chemical and heat treatment at low ({approx}120 Degree-Sign C) and high ({approx}800 Degree-Sign C) temperatures. In this contribution, we describe the design and performance of an ultra-high-vacuum furnace which uses an induction heating system to heat treat SRF cavities. Cavities are heated by radiation from the Nb susceptor. By using an all-niobium hot zone, contamination of the Nb cavity by foreign elements during heat treatment is minimized and allows avoiding subsequent chemical etching. The furnace was operated up to 1400 Degree-Sign C with a maximum pressure of {approx}1 Multiplication-Sign 10{sup -5} Torr and the maximum achievable temperature is estimated to be higher than 2000 Degree-Sign C. Initial results on the performance of a single cell 1.5 GHz cavity made of ingot Nb heat treated at 1200 Degree-Sign C using this new induction furnace and without subsequent chemical etching showed a reduction of the RF losses by a factor of {approx}2 compared to cavities made of fine-grain Nb which underwent standard chemical and heat treatments.

  1. Specific effects of cycling stressful temperatures upon phenotypic and genetic variability of size traits in

    E-Print Network [OSTI]

    Debat, Vincent

    of Drosophila melanogaster. We used either cold stress (daily cycle 8­25 C, average 16.5 C) or heat stress with cold stress but a decrease with heat stress. With respect to constant- temperature conditions, evolvability (genetic CV) was increased by daily cold stress, but decreased by daily heat stress. Within

  2. A Numerical Analysis of a Kinematic Stirling-Cycle Beat Pump for Space Conditioning Applications*

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    #12;A Numerical Analysis of a Kinematic Stirling-Cycle Beat Pump for Space Conditioning simulation was performed on a only recently been explored. 'To substantiate kinematic Stirling heat pump on a kinematic Stirling heat pump for third-order code. The effects of outdoor air space heating was made

  3. A novel thermomechanical energy conversion cycle Ian M. McKinley, Felix Y. Lee, Laurent Pilon

    E-Print Network [OSTI]

    Pilon, Laurent

    : Pyroelectric materials Direct energy conversion Waste heat harvesting Ferroelectric materials Olsen cycle, and structures such as buildings and bridges [1]. In addition, waste heat is the inevitable by-product of power of waste heat, such as electricity generation and transportation systems, also waste mechanical energy

  4. Hot Water Heating System Operation and Energy Conservation 

    E-Print Network [OSTI]

    Shao, Z.; Chen, H.; Wei, P.

    2006-01-01T23:59:59.000Z

    heating period, and temperature-flow adjustment with frequency control. The study shows the most energy efficient operating method is a variable flow heating system, which should be popularized to the heating field....

  5. System Design and Experimental Development of the Kalina Cycle Technology

    E-Print Network [OSTI]

    Kalina, A. I.; Leibowitz, H. M.

    , the heat exchange process in the boiler of a coal fired plant, geothermal plant, nuclear plant and waste heat bottoming cycle all differ in the combi nation of temperature and quantity of isothermal and sensible heat transfer. In the coal plant, appr...OXi mately 80 percent is transferred isothermally above 10SOF with the remainder transferred sensibly from 10SOF to lOOF. Low temperature geothermal is characterized by an evaporator inlet temperature in the 300-400F range with all heat transferred...

  6. Development of an Ionic-Liquid Absorption Heat Pump

    SciTech Connect (OSTI)

    Holcomb, Don

    2011-03-29T23:59:59.000Z

    Solar Fueled Products (SFP) is developing an innovative ionic-liquid absorption heat pump (ILAHP). The development of an ILAHP is extremely significant, as it could result in annual savings of more than 190 billion kW h of electrical energy and $19 billion. This absorption cooler uses about 75 percent less electricity than conventional cooling and heating units. The ILAHP also has significant environmental sustainability benefits, due to reduced CO2 emissions. Phase I established the feasibility and showed the economic viability of an ILAHP with these key accomplishments: • Used the breakthrough capabilities provided by ionic liquids which overcome the key difficulties of the common absorption coolers. • Showed that the theoretical thermodynamic performance of an ILAHP is similar to existing absorption-cooling systems. • Established that the half-effect absorption cycle reduces the peak generator temperature, improving collector efficiency and reducing collector area. • Component testing demonstrated that the most critical components, absorber and generator, operate well with conventional heat exchangers. • Showed the economic viability of an ILAHP. The significant energy savings, sustainability benefits, and economic viability are compelling reasons to continue the ILAHP development.

  7. The quality assurance of heat fused thermoplastic pipeline joints

    E-Print Network [OSTI]

    Earles, Larry Lee

    1982-01-01T23:59:59.000Z

    with no Heating Pressure 23 6 Temperature Distribution in Drisco 6500 with 25 psi Heating Pressure 7 Three-Dimensional Temperature Distribution in Drisco 6500 During the Fusion Cycle (Heating Time = 30 sec) 8 Heat Transfer Nodel Used to Nodel the Heating... of Temperature on Joint Strength from the Latin Square Using Drisco 8000 with the Bead Removed 52 25 Effect of Heating Time on Joint Strength From the Latin Square Using Drisco 8000 with the Bead Removed 53 26 Effect of Fusion Pressure on Joint Strength...

  8. Nitrogen expander cycles for large capacity liquefaction of natural gas

    SciTech Connect (OSTI)

    Chang, Ho-Myung; Park, Jae Hoon; Gwak, Kyung Hyun [Hong Ik University, Department of Mechanical Engineering, Seoul, 121-791 (Korea, Republic of); Choe, Kun Hyung [Korea Gas Corporation, Incheon, 406-130 (Korea, Republic of)

    2014-01-29T23:59:59.000Z

    Thermodynamic study is performed on nitrogen expander cycles for large capacity liquefaction of natural gas. In order to substantially increase the capacity, a Brayton refrigeration cycle with nitrogen expander was recently added to the cold end of the reputable propane pre-cooled mixed-refrigerant (C3-MR) process. Similar modifications with a nitrogen expander cycle are extensively investigated on a variety of cycle configurations. The existing and modified cycles are simulated with commercial process software (Aspen HYSYS) based on selected specifications. The results are compared in terms of thermodynamic efficiency, liquefaction capacity, and estimated size of heat exchangers. The combination of C3-MR with partial regeneration and pre-cooling of nitrogen expander cycle is recommended to have a great potential for high efficiency and large capacity.

  9. Low Temperature Heat Recovery for Boiler Systems

    E-Print Network [OSTI]

    Shook, J. R.; Luttenberger, D. B.

    be economically heated to within 50 0 F of the entering flue gas temperature. Other less common, but practical, uses for energy include driving a low-temperature electric turbine cycle or an absorption chilling cycle. An improvement in boiler efficiency of 3...% to 8% can normally be realized by cooling boiler flue gasses down to llO o F_200 0 F. This recovers a large quantity of the available sensible heat in most boiler flue gas streams. Efficiency can be improv ed by up to 10% if flue gas is cooled down...

  10. The effects of controlled thermal cycling on dislocation creation during semiconductor device processing

    E-Print Network [OSTI]

    Spaw, William James

    1971-01-01T23:59:59.000Z

    . The controlled cycling serves to reduce the temperature gradients existing within the wafers during such high temperature (&1000'C) heat-cycling as encountered during semiconductor device processing. These reduced dislocation densities are compared with those... UNDER THERMAL CYCLING CONDITIONS. V. CONCLUSIONS Page 25 REFERENCES APPENDIX 27 30 VITA LIST OF FIGURES Fi gure Page 3. 1 Furnace temperature during cycling from 800'C to Tmax and back. . . 3. 2 Temperature response curves for Thermco...

  11. FeCoCr nanocomposites for application in self-regulated rf heating K. J. Miller,1,a

    E-Print Network [OSTI]

    McHenry, Michael E.

    temperatures, moderate magnetic moments and provide increased heat capacity in a liquid used in a thermal cycle. Such ferrofluids can be moved and guided with an applied dc field, provide additional heat capacity to the liquid to their low Tc, moderate magnetic moment, and increased heat capacity in a liquid used in a thermal cycle

  12. DOE Booth Presentations From Grainger Show 2015

    Broader source: Energy.gov [DOE]

    DOE hosted its solid-state lighting informational booth February 16–18 at the annual Grainger Show in Orlando, FL. With over 17,000 attendees and over 750 exhibitors, the show gathered a wide range of Grainger customers—from universities to large hotel chains as well as Grainger team members to learn the latest about LED lighting.

  13. Overshooting by differential heating

    E-Print Network [OSTI]

    Andrássy, R

    2015-01-01T23:59:59.000Z

    On the long nuclear time scale of stellar main-sequence evolution, even weak mixing processes can become relevant for redistributing chemical species in a star. We investigate a process of "differential heating," which occurs when a temperature fluctuation propagates by radiative diffusion from the boundary of a convection zone into the adjacent radiative zone. The resulting perturbation of the hydrostatic equilibrium causes a flow that extends some distance from the convection zone. We study a simplified differential-heating problem with a static temperature fluctuation imposed on a solid boundary. The astrophysically relevant limit of a high Reynolds number and a low P\\'eclet number (high thermal diffusivity) turns out to be interestingly non-intuitive. We derive a set of scaling relations for the stationary differential heating flow. A numerical method adapted to a high dynamic range in flow amplitude needed to detect weak flows is presented. Our two-dimensional simulations show that the flow reaches a sta...

  14. Photovoltaics Life Cycle Analysis

    E-Print Network [OSTI]

    (air, water, solid) M, Q E PV array Photovoltaic modules Balance of System (BOS) (Inverters & Environmental Engineering Department Columbia University and National Photovoltaic (PV) EHS Research Center Brookhaven National Laboratory www.clca.columbia.edu www.pv.bnl.gov #12;2 The Life Cycle of PVThe Life Cycle

  15. Power Plant Cycling Costs

    SciTech Connect (OSTI)

    Kumar, N.; Besuner, P.; Lefton, S.; Agan, D.; Hilleman, D.

    2012-07-01T23:59:59.000Z

    This report provides a detailed review of the most up to date data available on power plant cycling costs. The primary objective of this report is to increase awareness of power plant cycling cost, the use of these costs in renewable integration studies and to stimulate debate between policymakers, system dispatchers, plant personnel and power utilities.

  16. Life Cycle Cost Estimate

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1997-03-28T23:59:59.000Z

    Life-cycle costs (LCCs) are all the anticipated costs associated with a project or program alternative throughout its life. This includes costs from pre-operations through operations or to the end of the alternative.This chapter discusses life cycle costs and the role they play in planning.

  17. Dangerous Bodies: Freak Shows, Expression, and Exploitation

    E-Print Network [OSTI]

    Fordham, Brigham A.

    2007-01-01T23:59:59.000Z

    Dangerous Bodies: Freak Shows, Expression, and ExploitationR.I. GEN. LAWS § 11-9-1. DANGEROUS BODIES Rhode Island does161 Id. Id. 165 id. 166 Id. DANGEROUS BODIES This argument

  18. Global transcriptome analysis of the heat shock response ofshewanella oneidensis

    SciTech Connect (OSTI)

    Gao, Haichun; Wang, Sarah; Liu, Xueduan; Yan, Tinfeng; Wu, Liyou; Alm, Eric; Arkin, Adam P.; Thompson, Dorothea K.; Zhou, Jizhong

    2004-04-30T23:59:59.000Z

    Shewanella oneidensis is an important model organism for bioremediation studies because of its diverse respiratory capabilities. However, the genetic basis and regulatory mechanisms underlying the ability of S. oneidensis to survive and adapt to various environmentally relevant stresses is poorly understood. To define this organism's molecular response to elevated growth temperatures, temporal gene expression profiles were examined in cells subjected to heat stress using whole-genome DNA microarrays for S. oneidensis MR-1. Approximately 15 percent (711) of the predicted S. oneidensis genes represented on the microarray were significantly up- or down-regulated (P < 0.05) over a 25-min period following shift to the heat shock temperature (42 C). As expected, the majority of S. oneidensis genes exhibiting homology to known chaperones and heat shock proteins (Hsps) were highly and transiently induced. In addition, a number of predicted genes encoding enzymes in glycolys is and the pentose cycle, [NiFe] dehydrogenase, serine proteases, transcriptional regulators (MerR, LysR, and TetR families), histidine kinases, and hypothetical proteins were induced in response to heat stress. Genes encoding membrane proteins were differentially expressed, suggesting that cells possibly alter their membrane composition or structure in response to variations in growth temperature. A substantial number of the genes encoding ribosomal proteins displayed down-regulated co-expression patterns in response to heat stress, as did genes encoding prophage and flagellar proteins. Finally, based on computational comparative analysis of the upstream promoter regions of S.oneidensis heat-inducible genes, a putative regulatory motif, showing high conservation to the Escherichia coli sigma 32-binding consensus sequence, was identified.

  19. Sensitivity Analysis of Reprocessing Cooling Times on Light Water Reactor and Sodium Fast Reactor Fuel Cycles

    SciTech Connect (OSTI)

    R. M. Ferrer; S. Bays; M. Pope

    2008-04-01T23:59:59.000Z

    The purpose of this study is to quantify the effects of variations of the Light Water Reactor (LWR) Spent Nuclear Fuel (SNF) and fast reactor reprocessing cooling time on a Sodium Fast Reactor (SFR) assuming a single-tier fuel cycle scenario. The results from this study show the effects of different cooling times on the SFR’s transuranic (TRU) conversion ratio (CR) and transuranic fuel enrichment. Also, the decay heat, gamma heat and neutron emission of the SFR’s fresh fuel charge were evaluated. A 1000 MWth commercial-scale SFR design was selected as the baseline in this study. Both metal and oxide CR=0.50 SFR designs are investigated.

  20. Biomass Gasification Combined Cycle

    SciTech Connect (OSTI)

    Judith A. Kieffer

    2000-07-01T23:59:59.000Z

    Gasification combined cycle continues to represent an important defining technology area for the forest products industry. The ''Forest Products Gasification Initiative'', organized under the Industry's Agenda 2020 technology vision and supported by the DOE ''Industries of the Future'' program, is well positioned to guide these technologies to commercial success within a five-to ten-year timeframe given supportive federal budgets and public policy. Commercial success will result in significant environmental and renewable energy goals that are shared by the Industry and the Nation. The Battelle/FERCO LIVG technology, which is the technology of choice for the application reported here, remains of high interest due to characteristics that make it well suited for integration with the infrastructure of a pulp production facility. The capital cost, operating economics and long-term demonstration of this technology area key input to future economically sustainable projects and must be verified by the 200 BDT/day demonstration facility currently operating in Burlington, Vermont. The New Bern application that was the initial objective of this project is not currently economically viable and will not be implemented at this time due to several changes at and around the mill which have occurred since the inception of the project in 1995. The analysis shows that for this technology, and likely other gasification technologies as well, the first few installations will require unique circumstances, or supportive public policies, or both to attract host sites and investors.

  1. Holographic Heat Engines

    E-Print Network [OSTI]

    Clifford V. Johnson

    2014-09-04T23:59:59.000Z

    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.

  2. Life-Cycle Assessment of Pyrolysis Bio-Oil Production

    SciTech Connect (OSTI)

    Steele, Philp; Puettmann, Maureen E.; Penmetsa, Venkata Kanthi; Cooper, Jerome E.

    2012-02-01T23:59:59.000Z

    As part ofthe Consortium for Research on Renewable Industrial Materials' Phase I life-cycle assessments ofbiofuels, lifecycle inventory burdens from the production of bio-oil were developed and compared with measures for residual fuel oil. Bio-oil feedstock was produced using whole southern pine (Pinus taeda) trees, chipped, and converted into bio-oil by fast pyrolysis. Input parameters and mass and energy balances were derived with Aspen. Mass and energy balances were input to SimaPro to determine the environmental performance of bio-oil compared with residual fuel oil as a heating fuel. Equivalent functional units of 1 MJ were used for demonstrating environmental preference in impact categories, such as fossil fuel use and global warming potential. Results showed near carbon neutrality of the bio-oil. Substituting bio-oil for residual fuel oil, based on the relative carbon emissions of the two fuels, estimated a reduction in CO2 emissions by 0.075 kg CO2 per MJ of fuel combustion or a 70 percent reduction in emission over residual fuel oil. The bio-oil production life-cycle stage consumed 92 percent of the total cradle-to-grave energy requirements, while feedstock collection, preparation, and transportation consumed 4 percent each. This model provides a framework to better understand the major factors affecting greenhouse gas emissions related to bio-oil production and conversion to boiler fuel during fast pyrolysis.

  3. Organic rankine cycle system for use with a reciprocating engine

    DOE Patents [OSTI]

    Radcliff, Thomas D.; McCormick, Duane; Brasz, Joost J.

    2006-01-17T23:59:59.000Z

    In a waste heat recovery system wherein an organic rankine cycle system uses waste heat from the fluids of a reciprocating engine, provision is made to continue operation of the engine even during periods when the organic rankine cycle system is inoperative, by providing an auxiliary pump and a bypass for the refrigerant flow around the turbine. Provision is also made to divert the engine exhaust gases from the evaporator during such periods of operation. In one embodiment, the auxiliary pump is made to operate simultaneously with the primary pump during normal operations, thereby allowing the primary pump to operate at lower speeds with less likelihood of cavitation.

  4. Geothermal heating

    SciTech Connect (OSTI)

    Aureille, M.

    1982-01-01T23:59:59.000Z

    The aim of the study is to demonstrate the viability of geothermal heating projects in energy and economic terms and to provide nomograms from which an initial estimate may be made without having to use data-processing facilities. The effect of flow rate and temperature of the geothermal water on drilling and on the network, and the effect of climate on the type of housing are considered.

  5. Water and Space Heating Heat Pumps 

    E-Print Network [OSTI]

    Kessler, A. F.

    1985-01-01T23:59:59.000Z

    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. Water and Space Heating Heat Pumps

    E-Print Network [OSTI]

    Kessler, A. F.

    1985-01-01T23:59:59.000Z

    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...

  7. Industrial Waste Heat Recovery Using Heat Pipes 

    E-Print Network [OSTI]

    Ruch, M. A.

    1981-01-01T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Chen, Y.; Zhao, J.

    2006-01-01T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Chen, Y.; Zhao, J.

    2006-01-01T23:59:59.000Z

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

  10. An H minority heating regime in Tore Supra showing improved L mode confinement

    E-Print Network [OSTI]

    Budny, Robert

    on the plasma facing components, parti- cle control through pumping and thermalization of fast particles for the next tokamak generation. High energy confinement will also be required for fusion reactor operation to the magnetic axis. The working gas is either deuterium or helium. The density is raised by gas puffing

  11. Quantum Optomechanical Heat Engine

    E-Print Network [OSTI]

    Keye Zhang; Francesco Bariani; Pierre Meystre

    2014-04-17T23:59:59.000Z

    We investigate theoretically a quantum optomechanical realization of a heat engine. In a generic optomechanical arrangement the optomechanical coupling between the cavity field and the oscillating end-mirror results in polariton normal mode excitations whose character depends on the pump detuning and the coupling strength. By varying that detuning it is possible to transform their character from phonon-like to photon-like, so that they are predominantly coupled to the thermal reservoir of phonons or photons, respectively. We exploit the fact that the effective temperatures of these two reservoirs are different to produce a Otto cycle along one of the polariton branches. We discuss the basic properties of the system in two different regimes: in the optical domain it is possible to extract work from the thermal energy of a mechanical resonator at finite temperature, while in the microwave range one can in principle exploit the cycle to extract work from the blackbody radiation background coupled to an ultra-cold atomic ensemble.

  12. Electrically heated DPF start-up strategy

    DOE Patents [OSTI]

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

    2012-04-10T23:59:59.000Z

    An exhaust system that processes exhaust generated by an engine has a diesel particulate filter (DPF) that is disposed downstream of the engine and that filters particulates in the exhaust. An electrical heater is disposed upstream of the DPF and selectively heats the exhaust to initiate combustion of the particulates. Heat generated by combustion of particulates in the heater induces combustion of particulates within the DPF. A control module selectively enables current flow to the electrical heater for an initial period of a DPF regeneration cycle, and limits exhaust flow while the electrical heater is heating to a predetermined soot combustion temperature.

  13. Thulium heat sources for space power applications

    SciTech Connect (OSTI)

    Alderman, C.J.

    1992-05-01T23:59:59.000Z

    Reliable power supplies for use in transportation and remote systems will be an important part of space exploration terrestrial activities. A potential power source is available in the rare earth metal, thulium. Fuel sources can be produced by activating Tm-169 targets in the space station reactor. The resulting Tm-170 heat sources can be used in thermoelectric generators to power instrumentation and telecommunications located at remote sites such as weather stations. As the heat source in a dynamic Sterling or Brayton cycle system, the heat source can provide a lightweight power source for rovers or other terrestrial transportation systems.

  14. Heating systems for heating subsurface formations

    DOE Patents [OSTI]

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

    2011-04-26T23:59:59.000Z

    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.

  15. EARTHQUAKE CAUSED RELEASES FROM A NUCLEAR FUEL CYCLE FACILITY

    SciTech Connect (OSTI)

    Charles W. Solbrig; Chad Pope; Jason Andrus

    2014-08-01T23:59:59.000Z

    The fuel cycle facility (FCF) at the Idaho National Laboratory is a nuclear facility which must be licensed in order to operate. A safety analysis is required for a license. This paper describes the analysis of the Design Basis Accident for this facility. This analysis involves a model of the transient behavior of the FCF inert atmosphere hot cell following an earthquake initiated breach of pipes passing through the cell boundary. The hot cell is used to process spent metallic nuclear fuel. Such breaches allow the introduction of air and subsequent burning of pyrophoric metals. The model predicts the pressure, temperature, volumetric releases, cell heat transfer, metal fuel combustion, heat generation rates, radiological releases and other quantities. The results show that releases from the cell are minimal and satisfactory for safety. This analysis method should be useful in other facilities that have potential for damage from an earthquake and could eliminate the need to back fit facilities with earthquake proof boundaries or lessen the cost of new facilities.

  16. Impact of Geoengineering Schemes on the Global Hydrological Cycle

    SciTech Connect (OSTI)

    Bala, G; Duffy, P; Taylor, K

    2007-12-07T23:59:59.000Z

    The rapidly rising CO{sub 2} level in the atmosphere has led to proposals of climate stabilization via 'Geoengineering' schemes that would mitigate climate change by intentionally reducing the solar radiation incident on earth's surface. In this paper, we address the impact of these climate stabilization schemes on the global hydrological cycle, using equilibrium simulations from an atmospheric general circulation model coupled to a slab ocean model. We show that insolation reductions sufficient to offset global-scale temperature increases lead to a decrease in the intensity of the global hydrologic cycle. This occurs because solar forcing is more effective in driving changes in global mean evaporation than is CO{sub 2} forcing of a similar magnitude. In the model used here, the hydrologic sensitivity, defined as the percentage change in global mean precipitation per degree warming, is 2.4% for solar forcing, but only 1.5% for CO{sub 2} forcing. Although other models and the climate system itself may differ quantitatively from this result, the conclusion can be understood based on simple considerations of the surface energy budget and thus is likely to be robust. Compared to changing temperature by altering greenhouse gas concentrations, changing temperature by varying insolation results in larger changes in net radiative fluxes at the surface; these are compensated by larger changes in latent and sensible heat fluxes. Hence the hydrological cycle is more sensitive to temperature adjustment via changes in insolation than changes in greenhouse gases. This implies that an alteration in solar forcing might offset temperature changes or hydrological changes from greenhouse warming, but could not cancel both at once.

  17. Chemical heat pump and chemical energy storage system

    DOE Patents [OSTI]

    Clark, Edward C. (Woodinville, WA); Huxtable, Douglas D. (Bothell, WA)

    1985-08-06T23:59:59.000Z

    A chemical heat pump and storage system employs sulfuric acid and water. In one form, the system includes a generator and condenser, an evaporator and absorber, aqueous acid solution storage and water storage. During a charging cycle, heat is provided to the generator from a heat source to concentrate the acid solution while heat is removed from the condenser to condense the water vapor produced in the generator. Water is then stored in the storage tank. Heat is thus stored in the form of chemical energy in the concentrated acid. The heat removed from the water vapor can be supplied to a heat load of proper temperature or can be rejected. During a discharge cycle, water in the evaporator is supplied with heat to generate water vapor, which is transmitted to the absorber where it is condensed and absorbed into the concentrated acid. Both heats of dilution and condensation of water are removed from the thus diluted acid. During the discharge cycle the system functions as a heat pump in which heat is added to the system at a low temperature and removed from the system at a high temperature. The diluted acid is stored in an acid storage tank or is routed directly to the generator for reconcentration. The generator, condenser, evaporator, and absorber all are operated under pressure conditions specified by the desired temperature levels for a given application. The storage tanks, however, can be maintained at or near ambient pressure conditions. In another form, the heat pump system is employed to provide usable heat from waste process heat by upgrading the temperature of the waste heat.

  18. System Modeling and Building Energy Simulations of Gas Engine Driven Heat Pump

    SciTech Connect (OSTI)

    Mahderekal, Isaac [Oak Ridge National Laboratory (ORNL); Vineyard, Edward [Oak Ridge National Laboratory (ORNL)

    2013-01-01T23:59:59.000Z

    To improve the system performance of a gas engine driven heat pump (GHP) system, an analytical modeling and experimental study has been made by using desiccant system in cooling operation (particularly in high humidity operations) and suction line waste heat recovery to augment heating capacity and efficiency. The performance of overall GHP system has been simulated with a detailed vapor compression heat pump system design model. The modeling includes: (1) GHP cycle without any performance improvements (suction liquid heat exchange and heat recovery) as a baseline (both in cooling and heating mode), (2) the GHP cycle in cooling mode with desiccant system regenerated by waste heat from engine incorporated, (3) GHP cycle in heating mode with heat recovery (recovered heat from engine). According to the system modeling results, by using the desiccant system the sensible heat ratio (SHR- sensible heat ratio) can be lowered to 40%. The waste heat of the gas engine can boost the space heating efficiency by 25% at rated operating conditions. In addtion,using EnergyPlus, building energy simulations have been conducted to assess annual energy consumptions of GHP in sixteen US cities, and the performances are compared to a baseline unit, which has a electrically-driven air conditioner with the seasonal COP of 4.1 for space cooling and a gas funace with 90% fuel efficiency for space heating.

  19. IFR fuel cycle

    SciTech Connect (OSTI)

    Battles, J.E.; Miller, W.E. (Argonne National Lab., IL (United States)); Lineberry, M.J.; Phipps, R.D. (Argonne National Lab., Idaho Falls, ID (United States))

    1992-01-01T23:59:59.000Z

    The next major milestone of the IFR program is engineering-scale demonstration of the pyroprocess fuel cycle. The EBR-II Fuel Cycle Facility has just entered a startup phase, which includes completion of facility modifications and installation and cold checkout of process equipment. This paper reviews the development of the electrorefining pyroprocess, the design and construction of the facility for the hot demonstration, the design and fabrication of the equipment, and the schedule and initial plan for its operation.

  20. IFR fuel cycle

    SciTech Connect (OSTI)

    Battles, J.E.; Miller, W.E. [Argonne National Lab., IL (United States); Lineberry, M.J.; Phipps, R.D. [Argonne National Lab., Idaho Falls, ID (United States)

    1992-04-01T23:59:59.000Z

    The next major milestone of the IFR program is engineering-scale demonstration of the pyroprocess fuel cycle. The EBR-II Fuel Cycle Facility has just entered a startup phase, which includes completion of facility modifications and installation and cold checkout of process equipment. This paper reviews the development of the electrorefining pyroprocess, the design and construction of the facility for the hot demonstration, the design and fabrication of the equipment, and the schedule and initial plan for its operation.

  1. Soil metagenomics and carbon cycling

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

    and carbon cycling Establishing a foundational understanding of the microbial and ecosystem factors that control carbon cycling to improve climate modeling and carbon...

  2. Dead heat

    SciTech Connect (OSTI)

    Oppenheimer, M.; Boyle, R.H.

    1990-01-01T23:59:59.000Z

    This paper reports on the prospect of global warming. This paper proposes a workable solution, and a road map for getting there. The author explains how we became addicted to fossil fuels and evokes a bleak picture should this dependence continue. But the book also explores how industry can become a vehicle for solving, instead of precipitating, the global environmental crisis. The decoupling of energy from pollution can be accomplished without sacrificing prosperity by powering the economy with solar energy. Dead Heat takes us step by step to a greenhouse-friendly world fueled only by the sun.

  3. New Regenerative Cycle for Vapor Compression Refrigeration

    SciTech Connect (OSTI)

    Mark J. Bergander

    2005-08-29T23:59:59.000Z

    The main objective of this project is to confirm on a well-instrumented prototype the theoretically derived claims of higher efficiency and coefficient of performance for geothermal heat pumps based on a new regenerative thermodynamic cycle as comparing to existing technology. In order to demonstrate the improved performance of the prototype, it will be compared to published parameters of commercially available geothermal heat pumps manufactured by US and foreign companies. Other objectives are to optimize the design parameters and to determine the economic viability of the new technology. Background (as stated in the proposal): The proposed technology closely relates to EERE mission by improving energy efficiency, bringing clean, reliable and affordable heating and cooling to the residential and commercial buildings and reducing greenhouse gases emission. It can provide the same amount of heating and cooling with considerably less use of electrical energy and consequently has a potential of reducing our nations dependence on foreign oil. The theoretical basis for the proposed thermodynamic cycle was previously developed and was originally called a dynamic equilibrium method. This theory considers the dynamic equations of state of the working fluid and proposes the methods for modification of T-S trajectories of adiabatic transformation by changing dynamic properties of gas, such as flow rate, speed and acceleration. The substance of this proposal is a thermodynamic cycle characterized by the regenerative use of the potential energy of two-phase flow expansion, which in traditional systems is lost in expansion valves. The essential new features of the process are: (1) The application of two-step throttling of the working fluid and two-step compression of its vapor phase. (2) Use of a compressor as the initial step compression and a jet device as a second step, where throttling and compression are combined. (3) Controlled ratio of a working fluid at the first and second step of compression. In the proposed system, the compressor compresses the vapor only to 50-60% of the final pressure, while the additional compression is provided by a jet device using internal potential energy of the working fluid flow. Therefore, the amount of mechanical energy required by a compressor is significantly reduced, resulting in the increase of efficiency (either COP or EER). The novelty of the cycle is in the equipment and in the way the multi-staging is accomplished. The anticipated result will be a new refrigeration system that requires less energy to accomplish a cooling task. The application of this technology will be for more efficient designs of: (1) Industrial chillers, (2) Refrigeration plants, (3) Heat pumps, (4) Gas Liquefaction plants, (5) Cryogenic systems.

  4. Quantum Brayton cycle with coupled systems as working substance

    E-Print Network [OSTI]

    X. L. Huang; L. C. Wang; X. X. Yi

    2013-01-16T23:59:59.000Z

    We explore the quantum version of Brayton cycle with a composite system as the working substance. The actual Brayton cycle consists of two adiabatic and two isobaric processes. Two pressures can be defined in our isobaric process, one corresponds to the external magnetic field (characterized by $F_x$) exerted on the system, while the other corresponds to the coupling constant between the subsystems (characterized by $F_y$). As a consequence, we can define two types of quantum Brayton cycle for the composite system. We find that the subsystem experiences a quantum Brayton cycle in one quantum Brayton cycle (characterized by $F_x$), whereas the subsystem's cycle is of quantum Otto in another Brayton cycle (characterized by $F_y$). The efficiency for the composite system equals to that for the subsystem in both cases, but the work done by the total system are usually larger than the sum of work done by the two subsystems. The other interesting finding is that for the cycle characterized by $F_y$, the subsystem can be a refrigerator while the total system is a heat engine. The result in the paper can be generalized to a quantum Brayton cycle with a general coupled system as the working substance.

  5. Indirect-fired gas turbine dual fuel cell power cycle

    DOE Patents [OSTI]

    Micheli, Paul L. (Sacramento, CA); Williams, Mark C. (Morgantown, WV); Sudhoff, Frederick A. (Morgantown, WV)

    1996-01-01T23:59:59.000Z

    A fuel cell and gas turbine combined cycle system which includes dual fuel cell cycles combined with a gas turbine cycle wherein a solid oxide fuel cell cycle operated at a pressure of between 6 to 15 atms tops the turbine cycle and is used to produce CO.sub.2 for a molten carbonate fuel cell cycle which bottoms the turbine and is operated at essentially atmospheric pressure. A high pressure combustor is used to combust the excess fuel from the topping fuel cell cycle to further heat the pressurized gas driving the turbine. A low pressure combustor is used to combust the excess fuel from the bottoming fuel cell to reheat the gas stream passing out of the turbine which is used to preheat the pressurized air stream entering the topping fuel cell before passing into the bottoming fuel cell cathode. The CO.sub.2 generated in the solid oxide fuel cell cycle cascades through the system to the molten carbonate fuel cell cycle cathode.

  6. Dual source heat pump

    DOE Patents [OSTI]

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

    1982-01-01T23:59:59.000Z

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

  7. Segmented heat exchanger

    DOE Patents [OSTI]

    Baldwin, Darryl Dean (Lafayette, IN); Willi, Martin Leo (Dunlap, IL); Fiveland, Scott Byron (Metamara, IL); Timmons, Kristine Ann (Chillicothe, IL)

    2010-12-14T23:59:59.000Z

    A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

  8. Development of the Hybrid Sulfur Thermochemical Cycle

    SciTech Connect (OSTI)

    Summers, William A.; Steimke, John L

    2005-09-23T23:59:59.000Z

    The production of hydrogen via the thermochemical splitting of water is being considered as a primary means for utilizing the heat from advanced nuclear reactors to provide fuel for a hydrogen economy. The Hybrid Sulfur (HyS) Process is one of the baseline candidates identified by the U.S. Department of Energy [1] for this purpose. The HyS Process is a two-step hybrid thermochemical cycle that only involves sulfur, oxygen and hydrogen compounds. Recent work has resulted in an improved process design with a calculated overall thermal efficiency (nuclear heat to hydrogen, higher heating value basis) approaching 50%. Economic analyses indicate that a nuclear hydrogen plant employing the HyS Process in conjunction with an advanced gas-cooled nuclear reactor system can produce hydrogen at competitive prices. Experimental work has begun on the sulfur dioxide depolarized electrolyzer, the major developmental component in the cycle. Proof-of-concept tests have established proton-exchange-membrane cells (a state-of-the-art technology) as a viable approach for conducting this reaction. This is expected to lead to more efficient and economical cell designs than were previously available. Considerable development and scale-up issues remain to be resolved, but the development of a viable commercial-scale HyS Process should be feasible in time to meet the commercialization schedule for Generation IV gas-cooled nuclear reactors.

  9. Regenerator optimization for Stirling cycle refrigeration

    SciTech Connect (OSTI)

    Colgate, S.A. [Los Alamos National Lab., NM (United States); Petschek, A.G. [New Mexico Tech, Socorro, NM (United States)

    1993-08-01T23:59:59.000Z

    A cryogenic regenerator for a Stirling cycle is designed using a fractional loss or entropy gain as the criterion of performance. The gas losses are treated separately from heat storage medium losses. For the optimum channel flow nonturbulent design, the maximization of heat transfer from the gas to the wall and the minimization of entropy production by friction leads to a gas flow velocity criterion of sound speed times loss fraction. This velocity with a given frequency leads to a Stirling cycle dead volume ratio and consequently a channel of specified length and width. The thermal properties of the channel wall must then accommodate this cyclic heat flow without substantially increasing the loss fraction. It is found that stainless steel or plastics are adequate for 30 to 300 K, but that lower temperature stages 4 to 30 K require either a special lead alloy of moderate conductivity or a segmented anisotropic construction of alternate highly conducting lead layers and alternate insulating glass or epoxy fiber glass spacers. An overall efficiency of {congruent} 50% of Carnot is predicted at a frequency of 30 Hz and a pressure of one atmosphere.

  10. Optimum Heat Power Cycles for Process Industrial Plants

    E-Print Network [OSTI]

    Waterland, A. F.

    1982-01-01T23:59:59.000Z

    Electric power cogeneration is compared with direct mechanical drives emphasizing the technical aspects having the greatest impact on energy economics. Both steam and gas turbine applications are discussed and practical methods of developing...

  11. Optimum Heat Power Cycles for Process Industrial Plants 

    E-Print Network [OSTI]

    Waterland, A. F.

    1982-01-01T23:59:59.000Z

    Electric power cogeneration is compared with direct mechanical drives emphasizing the technical aspects having the greatest impact on energy economics. Both steam and gas turbine applications are discussed and practical methods of developing...

  12. Waste Heat Recovery by Organic Fluid Rankine Cycle

    E-Print Network [OSTI]

    Verneau, A.

    1979-01-01T23:59:59.000Z

    powers of a few megawatts and medium temperatures, about 500 C/600 C, for flue gas. The very simple technology of turbines is shown. Three examples are presented. The first one is a test loop of 300 thermal kW built in BERTIN & Cie laboratory...

  13. Lessons Learned: Devolping Thermochemical Cycles for Solar Heat Storage

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetter Report:40PMDepartment ofs o u t h e22U.S.TableApplications

  14. Carnot cycle for an oscillator

    E-Print Network [OSTI]

    J. Arnaud; L. Chusseau; F. Philippe

    2001-11-20T23:59:59.000Z

    Carnot established in 1824 that the efficiency of cyclic engines operating between a hot bath at absolute temperature $T_{hot}$ and a bath at a lower temperature $T_{cold}$ cannot exceed $1-T_{cold}/T_{hot}$. We show that linear oscillators alternately in contact with hot and cold baths obey this principle in the quantum as well as in the classical regime. The expression of the work performed is derived from a simple prescription. Reversible and non-reversible cycles are illustrated. The paper begins with historical considerations and is essentially self-contained.

  15. Pollution Reduction System that Generates Profits (Cascading Closed Loop Cycle - CCLC) 

    E-Print Network [OSTI]

    Stinger, D. H.; Mian, F.

    2004-01-01T23:59:59.000Z

    WOW Energy Inc. (WOW) recently received notification from the patent office that its patent claims for the Cascading Closed Loop Cycle (CCLC) were valid for converting waste heat to electricity in a process using standard off-the-shelf components...

  16. M. Bahrami ENSC 461 (S 11) Assignment 2 1 Assignment #2 (Cycles)

    E-Print Network [OSTI]

    Bahrami, Majid

    Jan 23, 2011 Problem 1: (the Stirling cycle) Show that for an idealized Stirling cycle, the thermal efficiency is: H L th T T 1 Problem 2: (Otto cycle) An open, ideal Otto-cycle engine has a compression ratio of the turbine. i) draw a T-s diagram process for the compound engine ii) determine the work output

  17. Geothermal heat pumps for heating and cooling

    SciTech Connect (OSTI)

    Garg, S.C.

    1994-03-01T23:59:59.000Z

    Naval Facilities Engineering Service Center (NFESC) has been tasked by Naval Shore Facilities Energy Office to evaluate the NAS Patuxent River ground-source heat pump (GHP) installation. A large part of a building`s energy consumption consists of heating and air conditioning for occupant comfort. The space heating requirements are normally met by fossil-fuel-fired equipment or electric resistance heating. Cooling is provided by either air conditioners or heat pumps, both using electricity as an energy source.

  18. System study of an MHD/gas turbine combined-cycle baseload power plant. HTGL report No. 134

    SciTech Connect (OSTI)

    Annen, K.D.

    1981-08-01T23:59:59.000Z

    The MHD/gas turbine combined-cycle system has been designed specifically for applications where the availability of cooling water is very limited. The base case systems which were studied consisted of an MHD plant with a gas turbine bottoming plant, and required no cooling water. The gas turbine plant uses only air as its working fluid and receives its energy input from the MHD exhaust gases by means of metal tube heat exchangers. In addition to the base case systems, vapor cycle variation systems were considered which included the addition of a vapor cycle bottoming plant to improve the thermal efficiency. These systems required a small amount of cooling water. The MHD/gas turbine systems were modeled with sufficient detail, using realistic component specifications and costs, so that the thermal and economic performance of the system could be accurately determined. Three cases of MHD/gas turbine systems were studied, with Case I being similar to an MHD/steam system so that a direct comparison of the performances could be made, with Case II being representative of a second generation MHD system, and with Case III considering oxygen enrichment for early commercial applications. The systems are nominally 800 MW/sub e/ to 1000 MW/sub e/ in size. The results show that the MHD/gas turbine system has very good thermal and economic performances while requiring either little or no cooling water. Compared to the MHD/steam system which has a cooling tower heat load of 720 MW, the Base Case I MHD/gas turbine system has a heat rate which is 13% higher and a cost of electricity which is only 7% higher while requiring no cooling water. Case II results show that an improved performance can be expected from second generation MHD/gas turbine systems. Case III results show that an oxygen enriched MHD/gas turbine system may be attractive for early commercial applications in dry regions of the country.

  19. The Use of Water Vapor as a Refrigerant: Impact of Cycle Modifications on Commercial Viability

    SciTech Connect (OSTI)

    Brandon F. Lachner, Jr.; Gregory F. Nellis; Douglas T. Reindl

    2004-08-30T23:59:59.000Z

    This project investigated the economic viability of using water as the refrigerant in a 1000-ton chiller application. The most attractive water cycle configuration was found to be a flash-intercooled, two-stage cycle using centrifugal compressors and direct contact heat exchangers. Component level models were developed that could be used to predict the size and performance of the compressors and heat exchangers in this cycle as well as in a baseline, R-134a refrigeration cycle consistent with chillers in use today. A survey of several chiller manufacturers provided information that was used to validate and refine these component models. The component models were integrated into cycle models that were subsequently used to investigate the life-cycle costs of both an R-134a and water refrigeration cycle. It was found that the first cost associated with the water as a refrigerant cycle greatly exceeded the savings in operating costs associated with its somewhat higher COP. Therefore, the water refrigeration cycle is not an economically attractive option to today's R-134a refrigeration system. There are a number of other issues, most notably the requirements associated with purging non-condensable gases that accumulate in a direct contact heat exchanger, which will further reduce the economic viability of the water cycle.

  20. Earth's Heat Source - The Sun

    E-Print Network [OSTI]

    Oliver K. Manuel

    2009-05-05T23:59:59.000Z

    The Sun encompasses planet Earth, supplies the heat that warms it, and even shakes it. The United Nation Intergovernmental Panel on Climate Change (IPCC) assumed that solar influence on our climate is limited to changes in solar irradiance and adopted the consensus opinion of a Hydrogen-filled Sun, the Standard Solar Model (SSM). They did not consider the alternative solar model and instead adopted another consensus opinion: Anthropogenic greenhouse gases play a dominant role in climate change. The SSM fails to explain the solar wind, solar cycles, and the empirical link of solar surface activity with Earth changing climate. The alternative solar model, that was molded from an embarrassingly large number of unexpected observations revealed by space-age measurements since 1959, explains not only these puzzles but also how closely linked interactions between the Sun and its planets and other celestial bodies induce turbulent cycles of secondary solar characteristics that significantly affect Earth climate.

  1. Earth's Heat Source - The Sun

    E-Print Network [OSTI]

    Manuel, Oliver K

    2009-01-01T23:59:59.000Z

    The Sun encompasses planet Earth, supplies the heat that warms it, and even shakes it. The United Nation Intergovernmental Panel on Climate Change (IPCC) assumed that solar influence on our climate is limited to changes in solar irradiance and adopted the consensus opinion of a Hydrogen-filled Sun, the Standard Solar Model (SSM). They did not consider the alternative solar model and instead adopted another consensus opinion: Anthropogenic greenhouse gases play a dominant role in climate change. The SSM fails to explain the solar wind, solar cycles, and the empirical link of solar surface activity with Earth changing climate. The alternative solar model, that was molded from an embarrassingly large number of unexpected observations revealed by space-age measurements since 1959, explains not only these puzzles but also how closely linked interactions between the Sun and its planets and other celestial bodies induce turbulent cycles of secondary solar characteristics that significantly affect Earth climate.

  2. Helium process cycle

    DOE Patents [OSTI]

    Ganni, Venkatarao (Yorktown, VA)

    2008-08-12T23:59:59.000Z

    A unique process cycle and apparatus design separates the consumer (cryogenic) load return flow from most of the recycle return flow of a refrigerator and/or liquefier process cycle. The refrigerator and/or liquefier process recycle return flow is recompressed by a multi-stage compressor set and the consumer load return flow is recompressed by an independent consumer load compressor set that maintains a desirable constant suction pressure using a consumer load bypass control valve and the consumer load return pressure control valve that controls the consumer load compressor's suction pressure. The discharge pressure of this consumer load compressor is thereby allowed to float at the intermediate pressure in between the first and second stage recycle compressor sets. Utilizing the unique gas management valve regulation, the unique process cycle and apparatus design in which the consumer load return flow is separate from the recycle return flow, the pressure ratios of each recycle compressor stage and all main pressures associated with the recycle return flow are allowed to vary naturally, thus providing a naturally regulated and balanced floating pressure process cycle that maintains optimal efficiency at design and off-design process cycle capacity and conditions automatically.

  3. Helium process cycle

    DOE Patents [OSTI]

    Ganni, Venkatarao (Yorktown, VA)

    2007-10-09T23:59:59.000Z

    A unique process cycle and apparatus design separates the consumer (cryogenic) load return flow from most of the recycle return flow of a refrigerator and/or liquefier process cycle. The refrigerator and/or liquefier process recycle return flow is recompressed by a multi-stage compressor set and the consumer load return flow is recompressed by an independent consumer load compressor set that maintains a desirable constant suction pressure using a consumer load bypass control valve and the consumer load return pressure control valve that controls the consumer load compressor's suction pressure. The discharge pressure of this consumer load compressor is thereby allowed to float at the intermediate pressure in between the first and second stage recycle compressor sets. Utilizing the unique gas management valve regulation, the unique process cycle and apparatus design in which the consumer load return flow is separate from the recycle return flow, the pressure ratios of each recycle compressor stage and all main pressures associated with the recycle return flow are allowed to vary naturally, thus providing a naturally regulated and balanced floating pressure process cycle that maintains optimal efficiency at design and off-design process cycle capacity and conditions automatically.

  4. The Hybrid Sulfur Cycle for Nuclear Hydrogen Production

    SciTech Connect (OSTI)

    Summers, William A.; Gorensek, Maximilian B.; Buckner, Melvin R.

    2005-09-08T23:59:59.000Z

    Two Sulfur-based cycles--the Sulfur-Iodine (SI) and the Hybrid Sulfur (HyS)--have emerged as the leading thermochemical water-splitting processes for producing hydrogen utilizing the heat from advanced nuclear reactors. Numerous international efforts have been underway for several years to develop the SI Cycle, but development of the HyS Cycle has lagged. The purpose of this paper is to discuss the background, current status, recent development results, and the future potential for this thermochemical process. Savannah River National Laboratory (SRNL) has been supported by the U.S. Department of Energy Office of Nuclear Energy, Science, and Technology since 2004 to evaluate and to conduct research and development for the HyS Cycle. Process design studies and flowsheet optimization have shown that an overall plant efficiency (based on nuclear heat converted to hydrogen product, higher heating value basis) of over 50% is possible with this cycle. Economic studies indicate that a nuclear hydrogen plant based on this process can be economically competitive, assuming that the key component, the sulfur dioxide-depolarized electrolyzer, can be successfully developed. SRNL has recently demonstrated the use of a proton-exchange-membrane electrochemical cell to perform this function, thus holding promise for economical and efficient hydrogen production.

  5. Gas turbine cycles with solid oxide fuel cells. Part 1: Improved gas turbine power plant efficiency by use of recycled exhaust gases and fuel cell technology

    SciTech Connect (OSTI)

    Harvey, S.P.; Richter, H.J. (Dartmouth Coll., Hanover, NH (United States). Thayer School of Engineering)

    1994-12-01T23:59:59.000Z

    The energy conversion efficiency of the combustion process can be improved if immediate contact of fuel and oxygen is prevent4ed and an oxygen carrier is used. In a previous paper (Harvey et al., 1992), a gas turbine cycle was investigated in which part of the exhaust gases are recycled and used as oxygen-carrying components. For the optimized process, a theoretical thermal efficiency of 66.3% was achieved, based on the lower heating value (LHV) of the methane fuel. One means to further improve the exergetic efficiency of a power cycle is to utilize fuel cell technology. Solid oxide fuel cells (SOFC) have many features that make them attractive for utility and industrial applications. In this paper, the authors will therefore consider SOFC technology. In view of their high operating temperatures and the incomplete nature of the fuel oxidation process, fuel cells must be combined with conventional power generation technology to develop power plant configurations that are both functional and efficient. In this paper, the authors will show how monolithic SOFC (MSOFC) technology may be integrated into the previously described gas turbine cycle using recycled exhaust gases as oxygen carriers. An optimized cycle configuration will be presented based upon a detailed cycle analysis performance using Aspen Plus[trademark] process simulation software and a MSOFC fuel cell simulator developed by Argonne National Labs. The optimized cycle achieves a theoretical thermal efficiency of 77.7%, based on the LHV of the fuel.

  6. Answering Key Fuel Cycle Questions

    SciTech Connect (OSTI)

    Steven J. Piet; Brent W. Dixon; J. Stephen Herring; David E. Shropshire; Mary Lou Dunzik-Gougar

    2003-10-01T23:59:59.000Z

    The Advanced Fuel Cycle Initiative (AFCI) program has both “outcome” and “process” goals because it must address both waste already accumulating as well as completing the fuel cycle in connection with advanced nuclear power plant concepts. The outcome objectives are waste geological repository capacity and cost, energy security and sustainability, proliferation resistance, fuel cycle economics, and safety. The process objectives are readiness to proceed and adaptability and robustness in the face of uncertainties. A classic decision-making approach to such a multi-attribute problem would be to weight individual quantified criteria and calculate an overall figure of merit. This is inappropriate for several reasons. First, the goals are not independent. Second, the importance of different goals varies among stakeholders. Third, the importance of different goals is likely to vary with time, especially the “energy future.” Fourth, some key considerations are not easily or meaningfully quantifiable at present. Instead, at this point, we have developed 16 questions the AFCI program should answer and suggest an approach of determining for each whether relevant options improve meeting each of the program goals. We find that it is not always clear which option is best for a specific question and specific goal; this helps identify key issues for future work. In general, we suggest attempting to create as many win-win decisions (options that are attractive or neutral to most goals) as possible. Thus, to help clarify why the program is exploring the options it is, and to set the stage for future narrowing of options, we have developed 16 questions, as follows: · What are the AFCI program goals? · Which potential waste disposition approaches do we plan for? · What are the major separations, transmutation, and fuel options? · How do we address proliferation resistance? · Which potential energy futures do we plan for? · What potential external triggers do we plan for? · Should we separate uranium? · If we separate uranium, should we recycle it, store it or dispose of it? · Is it practical to plan to fabricate and handle “hot” fuel? · Which transuranic elements (TRU) should be separated and transmuted? · Of those TRU separated, which should be transmuted together? · Should we separate and/or transmute Cs and Sr isotopes that dominate near-term repository heating? · Should we separate and/or transmute very long-lived Tc and I isotopes? · Which separation technology? · What mix of transmutation technologies? · What fuel technology best supports the above decisions?

  7. Superradiant Quantum Heat Engine

    E-Print Network [OSTI]

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

    2015-04-22T23:59:59.000Z

    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.

  8. Original article Heat balance of a multistage spray-dryer

    E-Print Network [OSTI]

    Boyer, Edmond

    into account. From these data, the heat balance showed a dif- ference between inputs and outputs of 2.9% which may be interpreted as heat losses and probable errors. The specific heat consumption was close to 4 of the small flow rates of air used in both fluid beds. This specific heat consumption corresponds to 2.1 times

  9. Experimental validation of advanced regulations for superconducting magnet cooling undergoing periodic heat loads

    SciTech Connect (OSTI)

    Lagier, B.; Rousset, B.; Hoa, C.; Bonnay, P. [CEA Grenoble INAC/SBT, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France)

    2014-01-29T23:59:59.000Z

    Superconducting magnets used in tokamaks undergo periodic heat load caused by cycling plasma operations inducing AC losses, neutrons fluxes and eddy currents in magnet structures. In the cryogenic system of JT60-SA tokamak, the Auxiliary Cold Box (ACB) distributes helium from the refrigerator to the cryogenic users and in particular to the superconducting magnets. ACB comprises a saturated helium bath with immersed heat exchangers, extracting heat from independent cooling loops. The supercritical helium flow in each cooling loop is driven by a cold circulator. In order to safely operate the refrigerator during plasma pulses, the interface between the ACB and the refrigerator shall be as stable as possible, with well-balanced bath inlet and outlet mass flows during cycling operation. The solution presented in this paper relies on a combination of regulations to smooth pulsed heat loads and to keep a constant refrigeration power during all the cycle. Two smoothing strategies are presented, both regulating the outlet mass flow of the bath: the first one using the bath as a thermal buffer and the second one storing energy in the loop by varying the cold circulator speed. The bath outlet mass flow is also controlled by an immersed resistive heater which enables a constant evaporation rate in the bath when power coming from the loops is decreasing. The refrigeration power is controlled so that the compensating power remains within an acceptable margin. Experimental validation is achieved using the HELIOS facility. This facility running at CEA Grenoble since 2010 is a scaled down model of the ACB bath and Central Solenoid magnet cooling loop of the JT60-SA tokamak. Test results show performances and robustness of the regulations.

  10. Accepted Manuscript Title: A critical approach to the determination of optimal heat rejection pressure in

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    . A commercial refrigeration plant and a heat pump water heater were finally simulated to verify their energy. Keywords: CO2, Transcritical cycle, Optimisation, Refrigeration, Heat pump, Gas cooler. Nomenclature CAccepted Manuscript Title: A critical approach to the determination of optimal heat rejection

  11. Multiple source heat pump

    DOE Patents [OSTI]

    Ecker, Amir L. (Duncanville, TX)

    1983-01-01T23:59:59.000Z

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

  12. Regenerative Heater Optimization for Steam Turbo-Generation Cycles of Generation IV Nuclear Power Plants with a Comparison of Two Concepts for the Westinghouse International Reactor Innovative and Secure (IRIS)

    SciTech Connect (OSTI)

    Williams, W.C.

    2002-08-01T23:59:59.000Z

    The intent of this study is to discuss some of the many factors involved in the development of the design and layout of a steam turbo-generation unit as part of a modular Generation IV nuclear power plant. Of the many factors involved in the design and layout, this research will cover feed water system layout and optimization issues. The research is arranged in hopes that it can be generalized to any Generation IV system which uses a steam powered turbo-generation unit. The research is done using the ORCENT-II heat balance codes and the Salisbury methodology to be reviewed herein. The Salisbury methodology is used on an original cycle design by Famiani for the Westinghouse IRIS and the effects due to parameter variation are studied. The vital parameters of the Salisbury methodology are the incremental heater surface capital cost (S) in $/ft{sup 2}, the value of incremental power (I) in $/kW, and the overall heat transfer coefficient (U) in Btu/ft{sup 2}-degrees Fahrenheit-hr. Each is varied in order to determine the effects on the cycles overall heat rate, output, as well as, the heater surface areas. The effects of each are shown. Then the methodology is then used to compare the optimized original Famiani design consisting of seven regenerative feedwater heaters with an optimized new cycle concept, INRC8, containing four regenerative heaters. The results are shown. It can be seen that a trade between the complexity of the seven stage regenerative Famiani cycle and the simplicity of the INRC8 cycle can be made. It is desired that this methodology can be used to show the ability to evaluate modularity through the value of size a complexity of the system as well as the performance. It also shows the effectiveness of the Salisbury methodology in the optimization of regenerative cycles for such an evaluation.

  13. Proceedings: 7th International Conference on Cycle Chemistry in Fossil Plants

    SciTech Connect (OSTI)

    None

    2004-02-01T23:59:59.000Z

    The purity of boiler water, feedwater, and steam is central to ensuring component availability and reliability in fossil-fired plants. These proceedings of EPRI's Seventh International Conference on Cycle Chemistry in Fossil Plants address the state of the art in fossil plant and combined cycle/heat recovery steam generator (HRSG) cycle chemistry as well as international practices for corrosion control and water preparation and purification.

  14. Engineering a 70-percent efficient, indirect-fired fuel-cell bottomed turbine cycle

    SciTech Connect (OSTI)

    Williams, M.C.; Micheli, P.L.; Parsons, E.L. Jr.

    1996-08-01T23:59:59.000Z

    The authors introduce the natural gas, indirect-fired fuel-cell bottomed turbine cycle (NG-IFFC) as a novel power plant system for the distributed power and on-site markets in the 20 to 200 megawatt (MW) size range. The NG-IFFC system is a new METC-patented system. This power-plant system links the ambient pressure, carbonate fuel cell in tandem with a gas turbine, air compressor, combustor, and ceramic heat exchanger. Performance calculations based on Advanced System for Process Engineering (ASPEN) simulations show material and energy balances with expected power output. Early results indicated efficiencies and heat rates for the NG-IFFC are comparable to conventionally bottomed, carbonate fuel-cell steam-bottomed cycles. More recent calculations extended the in-tandem concept to produce near-stoichiometric usage of the oxygen. This is made possible by reforming the anode stream to completion and using all hydrogen fuel in what will need to be a special combustor. The performance increases dramatically to 70%.

  15. Ecosystem element cycling Introduction

    E-Print Network [OSTI]

    Ickert-Bond, Steffi

    Ecosystem element cycling Introduction An ecosystem consists of all the biological organisms and the physical environments they occupy together within a defined area [1]. The actual boundaries of an ecosystem are generally defined by researchers studying the ecosystem, who are usually interested in understanding

  16. GENERAL CIRCULATION Energy Cycle

    E-Print Network [OSTI]

    Grotjahn, Richard

    process. PE is useful for global energy balance. Solar radiant energy does not reach the Earth equally everywhere. On average, the tropics receive and absorb far more solar energy annually than the polar regionsGENERAL CIRCULATION Contents Energy Cycle Mean Characteristics Momentum Budget Overview Energy

  17. Life cycle assessment

    SciTech Connect (OSTI)

    Curran, M.A. [Environmental Protection Agency, Cincinnati, OH (United States)

    1994-12-31T23:59:59.000Z

    Life-Cycle Assessment (LCA) is a technical, data-based and holistic approach to define and subsequently reduce the environmental burdens associated with a product, process, or activity by identifying and quantifying energy and material usage and waste discharges, assessing the impact of those wastes on the environment, and evaluating and implementing opportunities to effect environmental improvements. The assessment includes the entire life-cycle of the product, process or activity encompassing extraction and processing of raw materials, manufacturing, transportation and distribution, use/reuse, recycling and final disposal. LCA is a useful tool for evaluating the environmental consequences of a product, process, or activity, however, current applications of LCA have not been performed in consistent or easily understood ways. This inconsistency has caused increased criticism of LCA. The EPA recognized the need to develop an LCA framework which could be used to provide consistent use across the board. Also, additional research is needed to enhance the understanding about the steps in the performance of an LCA and its appropriate usage. This paper will present the research activities of the EPA leading toward the development of an acceptable method for conducting LCA`s. This research has resulted in the development of two guidance manuals. The first manual is intended to be a practical guide to conducting and interpreting the life-cycle inventory. A nine-step approach to performing a comprehensive inventory is presented along with the general issues to be addressed. The second manual addresses life-cycle design.

  18. Combined Cycle Combustion Turbines

    E-Print Network [OSTI]

    Combined Cycle Combustion Turbines Steven Simmons February 27 2014 1 #12;CCCT Today's Discussion 1 Meeting Pricing of 4 advanced units using information from Gas Turbine World Other cost estimates from E E3 EIA Gas Turbine World California Energy Commission Date 2010 Oct 2012, Dec 2013 Apr 2013 2013 Apr

  19. San Bernardino District Heating District Heating Low Temperature...

    Open Energy Info (EERE)

    San Bernardino District Heating District Heating Low Temperature Geothermal Facility Facility San Bernardino District Heating Sector Geothermal energy Type District Heating...

  20. 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...

  1. 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...

  2. 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...

  3. Midland District Heating District Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Midland District Heating District Heating Low Temperature Geothermal Facility Facility Midland District Heating Sector Geothermal energy Type District Heating Location Midland,...

  4. 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...

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

    Energy Savers [EERE]

    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...

  6. Modelling cycle to cycle variations in an SI engine with detailed chemical kinetics

    SciTech Connect (OSTI)

    Etheridge, Jonathan; Mosbach, Sebastian; Kraft, Markus [Department of Chemical Engineering and Biotechnology, University of Cambridge (United Kingdom); Wu, Hao; Collings, Nick [Department of Engineering, University of Cambridge (United Kingdom)

    2011-01-15T23:59:59.000Z

    This paper presents experimental results and a new computational model that investigate cycle to cycle variations (CCV) in a spark ignition (SI) engine. An established stochastic reactor model (SRM) previously used to examine homogeneous charge compression ignition (HCCI) combustion has been extended by spark initiation, flame propagation and flame termination sub-models in order to simulate combustion in SI engines. The model contains a detailed chemical mechanism but relatively short computation times are achieved. The flame front is assumed to be spherical and centred at the spark location, and a pent roof and piston bowl geometry are accounted for. The model is validated by simulating the pressure profile and emissions from an iso-octane fuelled single cylinder research engine that showed low CCV. The effects of key parameters are investigated. Experimental results that show cycle to cycle fluctuations in a four-cylinder naturally aspirated gasoline fuelled SI engine are presented. The model is then coupled with GT-Power, a one-dimensional engine simulation tool, which is used to simulate the breathing events during a multi-cycle simulation. This allows an investigation of the cyclic fluctuations in peak pressure. The source and magnitude of nitric oxide (NO) emissions produced by different cycles are then investigated. It was found that faster burning cycles result in increased NO emissions compared with cycles that have a slower rate of combustion and that more is produced in the early stages of combustion compared with later in the cycle. The majority of NO was produced via the thermal mechanism just after combustion begins. (author)

  7. Industrial Waste Heat Recovery Using Heat Pipes

    E-Print Network [OSTI]

    Ruch, M. A.

    1981-01-01T23:59:59.000Z

    -expanding variety of industrial processes. One notable application in recent years has been for combustion airs preheat of fired heaters in petroleum refineries and petrochemical plants. Another recent development has been a waste heat recovery boiler using heat...

  8. Absorption heat pump system

    DOE Patents [OSTI]

    Grossman, Gershon (Oak Ridge, TN)

    1984-01-01T23:59:59.000Z

    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.

  9. Absorption heat pump system

    DOE Patents [OSTI]

    Grossman, G.

    1982-06-16T23:59:59.000Z

    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.

  10. Locating Heat Recovery Opportunities 

    E-Print Network [OSTI]

    Waterland, A. F.

    1981-01-01T23:59:59.000Z

    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...

  11. Locating Heat Recovery Opportunities

    E-Print Network [OSTI]

    Waterland, A. F.

    1981-01-01T23:59:59.000Z

    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...

  12. Photovoltaic roof heat flux

    E-Print Network [OSTI]

    Samady, Mezhgan Frishta

    2011-01-01T23:59:59.000Z

    transient the heat transfer model. T h i s required the roofto develop and calibrate heat transfer models to be able toE S station, the heat transfer models described i n sections

  13. THERMOCHEMICAL HEAT STORAGE FOR CONCENTRATED SOLAR POWER

    SciTech Connect (OSTI)

    PROJECT STAFF

    2011-10-31T23:59:59.000Z

    Thermal energy storage (TES) is an integral part of a concentrated solar power (CSP) system. It enables plant operators to generate electricity beyond on sun hours and supply power to the grid to meet peak demand. Current CSP sensible heat storage systems employ molten salts as both the heat transfer fluid and the heat storage media. These systems have an upper operating temperature limit of around 400 C. Future TES systems are expected to operate at temperatures between 600 C to 1000 C for higher thermal efficiencies which should result in lower electricity cost. To meet future operating temperature and electricity cost requirements, a TES concept utilizing thermochemical cycles (TCs) based on multivalent solid oxides was proposed. The system employs a pair of reduction and oxidation (REDOX) reactions to store and release heat. In the storage step, hot air from the solar receiver is used to reduce the oxidation state of an oxide cation, e.g. Fe3+ to Fe2+. Heat energy is thus stored as chemical bonds and the oxide is charged. To discharge the stored energy, the reduced oxide is re-oxidized in air and heat is released. Air is used as both the heat transfer fluid and reactant and no storage of fluid is needed. This project investigated the engineering and economic feasibility of this proposed TES concept. The DOE storage cost and LCOE targets are $15/kWh and $0.09/kWh respectively. Sixteen pure oxide cycles were identified through thermodynamic calculations and literature information. Data showed the kinetics of re-oxidation of the various oxides to be a key barrier to implementing the proposed concept. A down selection was carried out based on operating temperature, materials costs and preliminary laboratory measurements. Cobalt oxide, manganese oxide and barium oxide were selected for developmental studies to improve their REDOX reaction kinetics. A novel approach utilizing mixed oxides to improve the REDOX kinetics of the selected oxides was proposed. It partially replaces some of the primary oxide cations with selected secondary cations. This causes a lattice charge imbalance and increases the anion vacancy density. Such vacancies enhance the ionic mass transport and lead to faster re-oxidation. Reoxidation fractions of Mn3O4 to Mn2O3 and CoO to Co3O4 were improved by up to 16 fold through the addition of a secondary oxide. However, no improvement was obtained in barium based mixed oxides. In addition to enhancing the short term re-oxidation kinetics, it was found that the use of mixed oxides also help to stabilize or even improve the TES properties after long term thermal cycling. Part of this improvement could be attributed to a reduced grain size in the mixed oxides. Based on the measurement results, manganese-iron, cobalt-aluminum and cobalt iron mixed oxides have been proposed for future engineering scale demonstration. Using the cobalt and manganese mixed oxides, we were able to demonstrate charge and discharge of the TES media in both a bench top fixed bed and a rotary kiln-moving bed reactor. Operations of the fixed bed configuration are straight forward but require a large mass flow rate and higher fluid temperature for charging. The rotary kiln makes direct solar irradiation possible and provides significantly better heat transfer, but designs to transport the TES oxide in and out of the reactor will need to be defined. The final reactor and system design will have to be based on the economics of the CSP plant. A materials compatibility study was also conducted and it identified Inconel 625 as a suitable high temperature engineering material to construct a reactor holding either cobalt or manganese mixed oxides. To assess the economics of such a CSP plant, a packed bed reactor model was established as a baseline. Measured cobalt-aluminum oxide reaction kinetics were applied to the model and the influences of bed properties and process parameters on the overall system design were investigated. The optimal TES system design was found to be a network of eight fixed bed reactors at 18.75 MWth each with charge and

  14. Secondary Heat Exchanger Design and Comparison for Advanced High Temperature Reactor

    SciTech Connect (OSTI)

    Piyush Sabharwall; Ali Siahpush; Michael McKellar; Michael Patterson; Eung Soo Kim

    2012-06-01T23:59:59.000Z

    The goals of next generation nuclear reactors, such as the high temperature gas-cooled reactor and advance high temperature reactor (AHTR), are to increase energy efficiency in the production of electricity and provide high temperature heat for industrial processes. The efficient transfer of energy for industrial applications depends on the ability to incorporate effective heat exchangers between the nuclear heat transport system and the industrial process heat transport system. The need for efficiency, compactness, and safety challenge the boundaries of existing heat exchanger technology, giving rise to the following study. Various studies have been performed in attempts to update the secondary heat exchanger that is downstream of the primary heat exchanger, mostly because its performance is strongly tied to the ability to employ more efficient conversion cycles, such as the Rankine super critical and subcritical cycles. This study considers two different types of heat exchangers—helical coiled heat exchanger and printed circuit heat exchanger—as possible options for the AHTR secondary heat exchangers with the following three different options: (1) A single heat exchanger transfers all the heat (3,400 MW(t)) from the intermediate heat transfer loop to the power conversion system or process plants; (2) Two heat exchangers share heat to transfer total heat of 3,400 MW(t) from the intermediate heat transfer loop to the power conversion system or process plants, each exchanger transfers 1,700 MW(t) with a parallel configuration; and (3) Three heat exchangers share heat to transfer total heat of 3,400 MW(t) from the intermediate heat transfer loop to the power conversion system or process plants. Each heat exchanger transfers 1,130 MW(t) with a parallel configuration. A preliminary cost comparison will be provided for all different cases along with challenges and recommendations.

  15. Woven heat exchanger

    DOE Patents [OSTI]

    Piscitella, R.R.

    1984-07-16T23:59:59.000Z

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

  16. Total Space Heat-

    Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

    Commercial Buildings Energy Consumption Survey: Energy End-Use Consumption Tables Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration...

  17. 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...

  18. AGN Heating through Cavities and Shocks

    E-Print Network [OSTI]

    P. E. J. Nulsen; C. Jones; W. R. Forman; L. P. David; B. R. McNamara; D. A. Rafferty; L. Birzan; M. W. Wise

    2006-11-04T23:59:59.000Z

    Three comments are made on AGN heating of cooling flows. A simple physical argument is used to show that the enthalpy of a buoyant radio lobe is converted to heat in its wake. Thus, a significant part of ``cavity'' enthalpy is likely to end up as heat. Second, the properties of the repeated weak shocks in M87 are used to argue that they can plausibly prevent gas close to the AGN from cooling. As the most significant heating mechanism at work closest to the AGN, shock heating probably plays a critical role in the feedback mechanism. Third, results are presented from a survey of AGN heating rates in nearby giant elliptical galaxies. With inactive systems included, the overall AGN heating rate is reasonably well matched to the total cooling rate for the sample. Thus, intermittent AGN outbursts are energetically capable of preventing the hot atmospheres of these galaxies from cooling and forming stars.

  19. Crosslinked crystalline polymer and methods for cooling and heating

    SciTech Connect (OSTI)

    Salyer, Ival O. (Dayton, OH); Botham, Ruth A. (Dayton, OH); Ball, III, George L. (West Carrollton, OH)

    1980-01-01T23:59:59.000Z

    The invention relates to crystalline polyethylene pieces having optimum crosslinking for use in storage and recovery of heat, and it further relates to methods for storage and recovery of heat using crystalline polymer pieces having optimum crosslinking for these uses. Crystalline polymer pieces are described which retain at least 70% of the heat of fusion of the uncrosslinked crystalline polymer and yet are sufficiently crosslinked for the pieces not to stick together upon being cycled above and below the melting point of said polymer, preferably at least 80% of the heat of fusion with no substantial sticking together.

  20. Heat-activated cooling devices: A guidebook for general audiences

    SciTech Connect (OSTI)

    Wiltsee, G.

    1994-02-01T23:59:59.000Z

    Heat-activated cooling is refrigeration or air conditioning driven by heat instead of electricity. A mill or processing facility can us its waste fuel to air condition its offices or plant; using waste fuel in this way can save money. The four basic types of heat-activated cooling systems available today are absorption cycle, desiccant system, steam jet ejector, and steam turbine drive. Each is discussed, along with cool storage and biomass boilers. Steps in determining the feasibility of heat-activated cooling are discussed, as are biomass conversion, system cost and integration, permits, and contractor selection. Case studies are given.

  1. On the Limit Cycle of an Inflationary Universe

    E-Print Network [OSTI]

    Luca Salasnich

    1996-12-17T23:59:59.000Z

    We study the dynamics of a scalar inflaton field with a symmetric double--well potential and prove rigorously the existence of a limit cycle in its phase space. By using analytical and numerical arguments we show that the limit cycle is stable and give an analytical formula for its period.

  2. Stirling cycle engine

    DOE Patents [OSTI]

    Lundholm, Gunnar (Lund, SE)

    1983-01-01T23:59:59.000Z

    In a Stirling cycle engine having a plurality of working gas charges separated by pistons reciprocating in cylinders, the total gas content is minimized and the mean pressure equalization among the serial cylinders is improved by using two piston rings axially spaced at least as much as the piston stroke and by providing a duct in the cylinder wall opening in the space between the two piston rings and leading to a source of minimum or maximum working gas pressure.

  3. Rényi entropy flows from quantum heat engines

    E-Print Network [OSTI]

    Mohammad H. Ansari; Yuli V. Nazarov

    2015-03-20T23:59:59.000Z

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

  4. Design optimization of residential-sized air-source heat pumps

    E-Print Network [OSTI]

    Boecker, Curtis Layne

    1987-01-01T23:59:59.000Z

    larger heat exchangers and increased fan motor efficiency. Variable-speed heat pumps offer the greatest potential for efficiency increases as improvements in the variable-speed compressors progress. ACKNOWLEDGEMENTS I would like to thank Dr. Dennis O... for your support throughout. vi TABLE OF CONTENTS CHAPTER INTRODUCTION THE HEAT PUMP THERMODYNAMIC CYCLE Page Compressor Heat Exchanger Expansion Device Additional Equipment COMPUTER MODEL SELECTION AND VALIDATION . . 13 General Model...

  5. Theory of an optomechanical quantum heat engine

    E-Print Network [OSTI]

    Keye Zhang; Francesco Bariani; Pierre Meystre

    2014-08-13T23:59:59.000Z

    Coherent interconversion between optical and mechanical excitations in an optomechanical cavity can be used to engineer a quantum heat engine. This heat engine is based on an Otto cycle between a cold photonic reservoir and a hot phononic reservoir [Phys. Rev. Lett. 112, 150602 (2014)]. Building on our previous work, we (i) develop a detailed theoretical analysis of the work and the efficiency of the engine, and (ii) perform an investigation of the quantum thermodynamics underlying this scheme. In particular, we analyze the thermodynamic performance in both the dressed polariton picture and the original bare photon and phonon picture. Finally, (iii) a numerical simulation is performed to derive the full evolution of the quantum optomechanical system during the Otto cycle, by taking into account all relevant sources of noise.

  6. Life cycle assessment of a rock crusher

    SciTech Connect (OSTI)

    Landfield, A.H.; Karra, V.

    1999-07-01T23:59:59.000Z

    Nordberg, Inc., a capital equipment manufacturer, performed a Life Cycle Assessment study on its rock crusher to aid in making decisions on product design and energy improvements. Life Cycle Assessment (LCA) is a relatively new cutting edge environmental tool recently standardized by ISO that provides quantitative environmental and energy data on products or processes. This paper commences with a brief introduction to LCA and presents the system boundaries, modeling and assumptions for the rock crusher study. System boundaries include all life major cycle stages except manufacturing and assembly of the crusher. Results of the LCA show that over 99% of most of the flows into and out of the system may be attributed to the use phase of the rock crusher. Within the use phase itself, over 95% of each environmental inflow and outflow (with some exceptions) are attributed to electricity consumption, and not the replacement of spares/wears or lubricating oil over the lifetime of the crusher. Results tables and charts present selected environmental flows, including CO{sub 2} NOx, SOx, particulate matter, and energy consumption, for each of the rock crusher life cycle stages and the use phase. This paper aims to demonstrate the benefits of adopting a rigorous scientific approach to assess energy and environmental impacts over the life cycle of capital equipment. Nordberg has used these results to enhance its engineering efforts toward developing an even more energy efficient machine to further progress its vision of providing economic solutions to its customers by reducing the crusher operating (mainly electricity) costs.

  7. Rotary magnetic heat pump

    DOE Patents [OSTI]

    Kirol, Lance D. (Shelly, ID)

    1988-01-01T23:59:59.000Z

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

  8. Rotary magnetic heat pump

    DOE Patents [OSTI]

    Kirol, L.D.

    1987-02-11T23:59:59.000Z

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

  9. Mass and Heat Recovery 

    E-Print Network [OSTI]

    Hindawai, S. M.

    2010-01-01T23:59:59.000Z

    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...

  10. Fuel Cycle System Analysis Handbook

    SciTech Connect (OSTI)

    Steven J. Piet; Brent W. Dixon; Dirk Gombert; Edward A. Hoffman; Gretchen E. Matthern; Kent A. Williams

    2009-06-01T23:59:59.000Z

    This Handbook aims to improve understanding and communication regarding nuclear fuel cycle options. It is intended to assist DOE, Campaign Managers, and other presenters prepare presentations and reports. When looking for information, check here. The Handbook generally includes few details of how calculations were performed, which can be found by consulting references provided to the reader. The Handbook emphasizes results in the form of graphics and diagrams, with only enough text to explain the graphic, to ensure that the messages associated with the graphic is clear, and to explain key assumptions and methods that cause the graphed results. Some of the material is new and is not found in previous reports, for example: (1) Section 3 has system-level mass flow diagrams for 0-tier (once-through), 1-tier (UOX to CR=0.50 fast reactor), and 2-tier (UOX to MOX-Pu to CR=0.50 fast reactor) scenarios - at both static and dynamic equilibrium. (2) To help inform fast reactor transuranic (TRU) conversion ratio and uranium supply behavior, section 5 provides the sustainable fast reactor growth rate as a function of TRU conversion ratio. (3) To help clarify the difference in recycling Pu, NpPu, NpPuAm, and all-TRU, section 5 provides mass fraction, gamma, and neutron emission for those four cases for MOX, heterogeneous LWR IMF (assemblies mixing IMF and UOX pins), and a CR=0.50 fast reactor. There are data for the first 10 LWR recycle passes and equilibrium. (4) Section 6 provides information on the cycle length, planned and unplanned outages, and TRU enrichment as a function of fast reactor TRU conversion ratio, as well as the dilution of TRU feedstock by uranium in making fast reactor fuel. (The recovered uranium is considered to be more pure than recovered TRU.) The latter parameter impacts the required TRU impurity limits specified by the Fuels Campaign. (5) Section 7 provides flows for an 800-tonne UOX separation plant. (6) To complement 'tornado' economic uncertainty diagrams, which show at a glance combined uncertainty information, section 9.2 has a new set of simpler graphs that show the impact on fuel cycle costs for once through, 1-tier, and 2-tier scenarios as a function of key input parameters.

  11. Thulium-170 heat source

    DOE Patents [OSTI]

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

    1992-01-01T23:59:59.000Z

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

  12. Generator powered electrically heated diesel particulate filter

    DOE Patents [OSTI]

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

    2014-03-18T23:59:59.000Z

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

  13. Thermoelectric heat exchange element

    DOE Patents [OSTI]

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

    2007-08-14T23:59:59.000Z

    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.

  14. Mass and Heat Recovery

    E-Print Network [OSTI]

    Hindawai, S. M.

    2010-01-01T23:59:59.000Z

    - 1 - MASS AND HEAT RECOVERY SYSTEM SALAH MAHMOUD HINDAWI DIRECTOR HINDAWI FOR ENGINEERING SERVICES & CONTRACTING NEW DAMIETTA , EGYPT ABSTRACT : In the last few years heat recovery was under spot . and in air conditioning fields... ) as a heat recovery . and I use the water as a mass recovery . The source of mass and heat recovery is the condensate water which we were dispose and connect it to the drain lines . THE BENEFIT OF THIS SYSTEM ARE : 1) Using the heat energy from...

  15. Impingement cooling and heat transfer measurement using transient liquid crystal technique 

    E-Print Network [OSTI]

    Huang, Yizhe

    1996-01-01T23:59:59.000Z

    is used in this study to obtain the detailed heat transfer coefficient. Results show that a higher Reynolds number increases heat transfer over the entire impingement target surface. The flow exit orientation with crossflow affects the heat transfer...

  16. Brayton-Cycle Baseload Power Tower CSP System

    SciTech Connect (OSTI)

    Anderson, Bruce

    2013-12-31T23:59:59.000Z

    The primary objectives of Phase 2 of this Project were: 1. Engineer, fabricate, and conduct preliminary testing on a low-pressure, air-heating solar receiver capable of powering a microturbine system to produce 300kWe while the sun is shining while simultaneously storing enough energy thermally to power the system for up to 13 hours thereafter. 2. Cycle-test a high-temperature super alloy, Haynes HR214, to determine its efficacy for the system’s high-temperature heat exchanger. 3. Engineer the thermal energy storage system This Phase 2 followed Wilson’s Phase 1, which primarily was an engineering feasibility study to determine a practical and innovative approach to a full Brayton-cycle system configuration that could meet DOE’s targets. Below is a summary table of the DOE targets with Wilson’s Phase 1 Project results. The results showed that a Brayton system with an innovative (low pressure) solar receiver with ~13 hours of dry (i.e., not phase change materials or molten salts but rather firebrick, stone, or ceramics) has the potential to meet or exceed DOE targets. Such systems would consist of pre-engineered, standardized, factory-produced modules to minimize on-site costs while driving down costs through mass production. System sizes most carefully analyzed were in the range of 300 kWe to 2 MWe. Such systems would also use off-the-shelf towers, blowers, piping, microturbine packages, and heliostats. Per DOE’s instructions, LCOEs are based on the elevation and DNI levels of Daggett, CA, for a 100 MWe power plant following 2 GWe of factory production of the various system components. Success criteria DOE targets Wilson system LCOE DOE’s gas price $6.75/MBtu 9 cents/kWh 7.7 cents/kWh LCOE Current gas price $4.71/MBtu NA 6.9 cents/kWh Capacity factor 75% (6500hr) 75-100% Solar fraction 85% (5585hr) >5585hr Receiver cost $170/kWe $50/kWe Thermal storage cost $20/kWhth $13/kWhth Heliostat cost $120/m2 $89.8/m2

  17. Two-dimensional model of the air flow and temperature distribution in a cavity-type heat receiver of a solar stirling engine

    SciTech Connect (OSTI)

    Makhkamov, K.K.; Ingham, D.B.

    1999-11-01T23:59:59.000Z

    A theoretical study on the air flow and temperature in the heat receiver, affected by free convection, of a Stirling Engine for a Dish/Stirling Engine Power System is presented. The standard {kappa}-{epsilon} turbulence model for the fluid flow has been used and the boundary conditions employed were obtained using a second level mathematical model of the Stirling Engine working cycle. Physical models for the distribution of the solar insolation from the Concentrator on the bottom and side walls of the cavity-type heat receiver have been taken into account. The numerical results show that most of the heat losses in the receiver are due to re-radiation from the cavity and conduction through the walls of the cavity. It is in the region of the boundary of the input window of the heat receiver where there is a sensible reduction in the temperature in the shell of the heat exchangers and this is due to the free convection of the air. Further, the numerical results show that convective heat losses increase with decreasing tilt angle.

  18. Geothermal Life Cycle Calculator

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

    Sullivan, John

    This calculator is a handy tool for interested parties to estimate two key life cycle metrics, fossil energy consumption (Etot) and greenhouse gas emission (ghgtot) ratios, for geothermal electric power production. It is based solely on data developed by Argonne National Laboratory for DOE’s Geothermal Technologies office. The calculator permits the user to explore the impact of a range of key geothermal power production parameters, including plant capacity, lifetime, capacity factor, geothermal technology, well numbers and depths, field exploration, and others on the two metrics just mentioned. Estimates of variations in the results are also available to the user.

  19. Quantum thermodynamic cooling cycle

    E-Print Network [OSTI]

    Jose P. Palao; Ronnie Kosloff; Jeffrey M. Gordon

    2001-06-08T23:59:59.000Z

    The quantum-mechanical and thermodynamic properties of a 3-level molecular cooling cycle are derived. An inadequacy of earlier models is rectified in accounting for the spontaneous emission and absorption associated with the coupling to the coherent driving field via an environmental reservoir. This additional coupling need not be dissipative, and can provide a thermal driving force - the quantum analog of classical absorption chillers. The dependence of the maximum attainable cooling rate on temperature, at ultra-low temperatures, is determined and shown to respect the recently-established fundamental bound based on the second and third laws of thermodynamics.

  20. Geothermal Life Cycle Calculator

    SciTech Connect (OSTI)

    Sullivan, John

    2014-03-11T23:59:59.000Z

    This calculator is a handy tool for interested parties to estimate two key life cycle metrics, fossil energy consumption (Etot) and greenhouse gas emission (ghgtot) ratios, for geothermal electric power production. It is based solely on data developed by Argonne National Laboratory for DOE’s Geothermal Technologies office. The calculator permits the user to explore the impact of a range of key geothermal power production parameters, including plant capacity, lifetime, capacity factor, geothermal technology, well numbers and depths, field exploration, and others on the two metrics just mentioned. Estimates of variations in the results are also available to the user.

  1. Quantum thermodynamic cooling cycle

    E-Print Network [OSTI]

    Palao, J P; Gordon, J M; Palao, Jose P.; Kosloff, Ronnie; Gordon, Jeffrey M.

    2001-01-01T23:59:59.000Z

    The quantum-mechanical and thermodynamic properties of a 3-level molecular cooling cycle are derived. An inadequacy of earlier models is rectified in accounting for the spontaneous emission and absorption associated with the coupling to the coherent driving field via an environmental reservoir. This additional coupling need not be dissipative, and can provide a thermal driving force - the quantum analog of classical absorption chillers. The dependence of the maximum attainable cooling rate on temperature, at ultra-low temperatures, is determined and shown to respect the recently-established fundamental bound based on the second and third laws of thermodynamics.

  2. Water Cycle Pilot Study

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsing Maps1DOE AwardsDNitrateEnergy Watch1 Water Cycle

  3. Methanogenic burst in the end-Permian carbon cycle

    E-Print Network [OSTI]

    Rothman, Daniel H.

    The end-Permian extinction is associated with a mysterious disruption to Earth’s carbon cycle. Here we identify causal mechanisms via three observations. First, we show that geochemical signals indicate superexponential ...

  4. Duty Cycle Analysis & Tools: Maximizing Vehicle Performance (Presentation)

    SciTech Connect (OSTI)

    Walkowicz, K.

    2009-10-28T23:59:59.000Z

    Shows that the benefits of using hybrid vehicle trucks in fleets depends on the duty cycle, or how the vehicles will be driven (e.g., stop and go) over a particular route (e.g., urban or rural).

  5. DEVELOPMENT OF COLD CLIMATE HEAT PUMP USING TWO-STAGE COMPRESSION

    SciTech Connect (OSTI)

    Rice, C Keith [ORNL; Abdelaziz, Omar [ORNL; Shrestha, Som S [ORNL

    2015-01-01T23:59:59.000Z

    This paper uses a well-regarded, hardware based heat pump system model to investigate a two-stage economizing cycle for cold climate heat pump applications. The two-stage compression cycle has two variable-speed compressors. The high stage compressor was modelled using a compressor map, and the low stage compressor was experimentally studied using calorimeter testing. A single-stage heat pump system was modelled as the baseline. The system performance predictions are compared between the two-stage and single-stage systems. Special considerations for designing a cold climate heat pump are addressed at both the system and component levels.

  6. MID-CYCLE CHANGES IN ETA CARINAE

    SciTech Connect (OSTI)

    Martin, John C. [Physics and Astronomy Department, University of Illinois, Springfield, IL 62703 (United States); Davidson, Kris; Humphreys, Roberta M.; Mehner, Andrea [Astronomy Department, University of Minnesota, Minneapolis, MN 55455 (United States)

    2010-05-15T23:59:59.000Z

    In late 2006, ground-based photometry of {eta} Car plus the Homunculus showed an unexpected decrease in its integrated apparent brightness, an apparent reversal of its long-term brightening. Subsequent Hubble Space Telescope (HST)/WFPC2 photometry of the central star in the near-UV showed that this was not a simple reversal. This multi-wavelength photometry did not support increased extinction by dust as the explanation for the decrease in brightness. A spectrum obtained with the Gemini Multi-Object Spectrograph on the Gemini-South telescope revealed subtle changes mid-way in {eta} Car's 5.5 yr spectroscopic cycle when compared with HST/Space Telescope Imaging Spectrograph (STIS) spectra at the same phase in the cycle. At mid-cycle the secondary star is 20-30 AU from the primary. We suggest that the spectroscopic changes are consistent with fluctuations in the density and velocity of the primary star's wind, unrelated to the 5.5 yr cycle but possibly related to its latitude-dependent morphology. We also discuss subtle effects that must be taken into account when comparing ground-based and HST/STIS spectra.

  7. HEMISPHERIC HELICITY TREND FOR SOLAR CYCLE 24

    SciTech Connect (OSTI)

    Hao Juan; Zhang Mei, E-mail: haojuan@nao.cas.cn [Key Laboratory of Solar Activity, National Astronomical Observatory, Chinese Academy of Sciences, A20 Datun Road, Chaoyang District, Beijing 100012 (China)

    2011-06-01T23:59:59.000Z

    Using vector magnetograms obtained with the Spectro-polarimeter (SP) on board Hinode satellite, we studied two helicity parameters (local twist and current helicity) of 64 active regions that occurred in the descending phase of solar cycle 23 and the ascending phase of solar cycle 24. Our analysis gives the following results. (1) The 34 active regions of the solar cycle 24 follow the so-called hemispheric helicity rule, whereas the 30 active regions of the solar cycle 23 do not. (2) When combining all 64 active regions as one sample, they follow the hemispheric helicity sign rule as in most other observations. (3) Despite the so-far most accurate measurement of vector magnetic field given by SP/Hinode, the rule is still weak with large scatters. (4) The data show evidence of different helicity signs between strong and weak fields, confirming previous result from a large sample of ground-based observations. (5) With two example sunspots we show that the helicity parameters change sign from the inner umbra to the outer penumbra, where the sign of penumbra agrees with the sign of the active region as a whole. From these results, we speculate that both the {Sigma}-effect (turbulent convection) and the dynamo have contributed in the generation of helicity, whereas in both cases turbulence in the convection zone has played a significant role.

  8. Heat Integrate Heat Engines in Process Plants

    E-Print Network [OSTI]

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

    ~C. T min Table 3. Problem Table Algorithm Applied to Petrochemicals Process Interval GJ ltiour 'Temperatures ! C! 2 ) ? ~ Cold. Hot Aecumulated Heat Heat FJ.owa Interval Streams StrePlS Deficit. Input OUtput -OUtt!utInput. 20 30 -2... of heat which can be passed on in this manner is performed in column 2 and column 3 of Table 3. It is initially assumed that the heat input from external utilities is zero. This is represented in Table 3 by a zero input to the top interval. Having...

  9. A heat engine with unique characteristics

    SciTech Connect (OSTI)

    Baranescu, G.S. [ATR Corp., Western Springs, IL (United States)

    1996-12-31T23:59:59.000Z

    A heat engine which operates with one heat reservoir is described. The engine transforms the heat input completely into work by using a compressed fluid from a resource of the environment. For this reason the engine is not a perpetual motion machine of the second kind. The characteristics of the engine are analyzed, and the ways for achieving the most economic use of the compressed fluid are described. The principle of operation of the engine shows that the concepts of phenomenological thermodynamics regarding heat and its transformation in other forms of energy are not true.

  10. Modelling Heat Transfer of Carbon Nanotubes

    E-Print Network [OSTI]

    Yang, Xin-She

    2010-01-01T23:59:59.000Z

    Modelling heat transfer of carbon nanotubes is important for the thermal management of nanotube-based composites and nanoelectronic device. By using a finite element method for three-dimensional anisotropic heat transfer, we have simulated the heat conduction and temperature variations of a single nanotube, a nanotube array and a part of nanotube-based composite surface with heat generation. The thermal conductivity used is obtained from the upscaled value from the molecular simulations or experiments. Simulations show that nanotube arrays have unique cooling characteristics due to its anisotropic thermal conductivity.

  11. Insulation and Heat Treatment of Bi-2212 Wire for Wind-and-React Coils

    SciTech Connect (OSTI)

    Peter K. F. Hwang

    2007-10-22T23:59:59.000Z

    Higher Field Magnets demand higher field materials such as Bi-2212 round superconducting wire. The Bi-2212 wire manufacture process depends on the coil fabrication method and wire insulation material. Considering the wind-and-react method, the coil must unifirmly heated to the melt temperature and uniformly cooled to the solidification temperature. During heat treat cycle for tightly wound coils, the leakage melt from conductor can chemically react with insulation on the conductor and creat short turns in the coils. In this research project, conductor, insulation, and coils are made to systemically study the suitable insulation materials, coil fabrication method, and heat treatment cycles. In this phase I study, 800 meters Bi-2212 wire with 3 different insulation materials have been produced. Best insulation material has been identified after testing six small coils for insulation integrity and critical current at 4.2 K. Four larger coils (2" dia) have been also made with Bi-2212 wrapped with best insulation and with different heattreatment cycle. These coils were tested for Ic in a 6T background field and at 4.2 K. The test result shows that Ic from 4 coils are very close to short samples (1 meter) result. It demonstrates that HTS coils can be made with Bi-2212 wire with best insulation consistently. Better wire insulation, improving coil winding technique, and wire manufacture process can be used for a wide range of high field magnet application including acclerators such as Muon Collider, fusion energy research, NMR spectroscopy, MRI, and other industrial magnets.

  12. Experimental Research on Solar Assisted Heat Pump Heating System with Latent Heat Storage 

    E-Print Network [OSTI]

    Han, Z.; Zheng, M.; Liu, W.; Wang, F.

    2006-01-01T23:59:59.000Z

    Assisted Heat Pump Heating System with Latent Heat Storage. In this system, solar energy is the major heat source for a heat pump, and the supplementary heat source is soil. The disagreement in time between the space heat load and heat collected by solar...

  13. High-lift chemical heat pump technologies for industrial processes

    SciTech Connect (OSTI)

    Olszewski, M.; Zaltash, A.

    1995-03-01T23:59:59.000Z

    Traditionally industrial heat pumps (IHPs) have found applications on a process specific basis with reject heat from a process being upgraded and returned to the process. The IHP must be carefully integrated into a process since improper placement may result in an uneconomic application. Industry has emphasized a process integration approach to the design and operation of their plants. Heat pump applications have adopted this approach and the area of applicability was extended by utilizing a process integrated approach where reject heat from one process is upgraded and then used as input for another process. The DOE IHP Program has extended the process integration approach of heat pump application with a plant utility emphasis. In this design philosophy, reject heat from a process is upgraded to plant utility conditions and fed into the plant distribution system. This approach has the advantage that reject heat from any pr@s can be used as input and the output can be used at any location within the plant. Thus the approach can be easily integrated into existing industrial applications and all reject heat streams are potential targets of opportunity. The plant utility approach can not be implemented without having heat pumps with high-lift capabilities (on the order of 65{degree}C). Current heat pumps have only about half the lift capability required. Thus the current emphasis for the DOE IHP Program is the development of high lift chemical heat pumps that can deliver heat more economically to higher heat delivery temperatures. This is achieved with innovative cooling (refrigeration) and heating technologies which are based on advanced cycles and advanced working fluids or a combination of both. This paper details the plan to develop economically competitive, environmentally acceptable heat pump technologies that are capable of providing the delivery temperature and lift required to supply industrial plant utility-grade process heating and/or cooling.

  14. An Energy Savings Model for the Heat Treatment of Castings

    SciTech Connect (OSTI)

    Y. Rong; R. Sisson; J. Morral; H. Brody

    2006-12-31T23:59:59.000Z

    An integrated system of software, databases, and design rules have been developed, verified, and to be marketed to enable quantitative prediction and optimization of the heat treatment of aluminum castings to increase quality, increase productivity, reduce heat treatment cycle times and reduce energy consumption. The software predicts the thermal cycle in critical locations of individual components in a furnace, the evolution of microstructure, and the attainment of properties in heat treatable aluminum alloy castings. The model takes into account the prior casting process and the specific composition of the component. The heat treatment simulation modules can be used in conjunction with software packages for simulation of the casting process. The system is built upon a quantitative understanding of the kinetics of microstructure evolution in complex multicomponent alloys, on a quantitative understanding of the interdependence of microstructure and properties, on validated kinetic and thermodynamic databases, and validated quantitative models.

  15. Kouchoul cycle implication in the Tailer engine cycle

    SciTech Connect (OSTI)

    Arques, P.

    1996-12-31T23:59:59.000Z

    The author presents here the study of the Tailer engine modified cycle using the concept of load transfer for the Kouchoul cycle. Theoretical equations and numerical simulation of the Tailer engine modified cycle implicating the Kouchoul cycle are developed. The Tailer engine modified cycle can be improved by approaching cycles of spark plug engines by the addition of a phase of cooling of gases to the bottom dead center (bdc). This is possible only by putting a reservoir of cooled gas in communication with the cylinder to the bottom dead center. So as not to complicate the kinematic of the engine, the communication between cylinder and cooled reservoir is executed by some holes of 1 mm distributed on the whole periphery of the cylinder at the bdc.

  16. Materials, Turbomachinery and Heat Exchangers for Supercritical CO2 Systems

    SciTech Connect (OSTI)

    Anderson, Mark; Nellis, Greg; Corradini, Michael

    2012-10-19T23:59:59.000Z

    The objective of this project is to produce the necessary data to evaluate the performance of the supercritical carbon dioxide cycle. The activities include a study of materials compatibility of various alloys at high temperatures, the heat transfer and pressure drop in compact heat exchanger units, and turbomachinery issues, primarily leakage rates through dynamic seals. This experimental work will serve as a test bed for model development and design calculations, and will help define further tests necessary to develop high-efficiency power conversion cycles for use on a variety of reactor designs, including the sodium fast reactor (SFR) and very high-temperature gas reactor (VHTR). The research will be broken into three separate tasks. The first task deals with the analysis of materials related to the high-temperature S-CO{sub 2} Brayton cycle. The most taxing materials issues with regard to the cycle are associated with the high temperatures in the reactor side heat exchanger and in the high-temperature turbine. The system could experience pressures as high as 20MPa and temperatures as high as 650°C. The second task deals with optimization of the heat exchangers required by the S-CO{sub 2} cycle; the S-CO{sub 2} flow passages in these heat exchangers are required whether the cycle is coupled with a VHTR or an SFR. At least three heat exchangers will be required: the pre-cooler before compression, the recuperator, and the heat exchanger that interfaces with the reactor coolant. Each of these heat exchangers is unique and must be optimized separately. The most challenging heat exchanger is likely the pre-cooler, as there is only about a 40°C temperature change but it operates close to the CO{sub 2} critical point, therefore inducing substantial changes in properties. The proposed research will focus on this most challenging component. The third task examines seal leakage through various dynamic seal designs under the conditions expected in the S-CO{sub 2} cycle, including supercritical, choked, and two-phase flow conditions.

  17. Testing and analysis of immersed heat exchangers

    SciTech Connect (OSTI)

    Farrington, R.B.; Bingham, C.E.

    1986-08-01T23:59:59.000Z

    The objectives were to determine the performance of four immersed, ''supply-side'' heat exchangers used in solar domestic-hot-water systems; to examine the effects of flow rate, temperature difference, and coil configuration on performance; and to develop a simple model to predict the performance of immersed heat exchangers. We tested four immersed heat exchangers: a smooth coil, a finned spiral, a single-wall bayonet, and a double-wall bayonet. We developed two analyticl models and a simple finite difference model. We experimentally verified that the performance of these heat exchangers depends on the flow rate through them; we also showed that the temperature difference between the heat exchanger's inlet and the storage tank can strongly affect a heat exchanger's performance. We also compared the effects of the heat exchanger's configuration and correlated Nusselt and Rayleigh numbers for each heat exchanger tested. The smooth coil had a higher effectiveness than the others, while the double-wall bayonet had a very low effectiveness. We still do not know the long-term effectiveness of heat exchangers regarding scale accumulation, nor do we know the effects of very low flow rates on a heat exchanger's performance.

  18. Recuperative supercritical carbon dioxide cycle

    DOE Patents [OSTI]

    Sonwane, Chandrashekhar; Sprouse, Kenneth M; Subbaraman, Ganesan; O'Connor, George M; Johnson, Gregory A

    2014-11-18T23:59:59.000Z

    A power plant includes a closed loop, supercritical carbon dioxide system (CLS-CO.sub.2 system). The CLS-CO.sub.2 system includes a turbine-generator and a high temperature recuperator (HTR) that is arranged to receive expanded carbon dioxide from the turbine-generator. The HTR includes a plurality of heat exchangers that define respective heat exchange areas. At least two of the heat exchangers have different heat exchange areas.

  19. Life-cycle cost and payback period analysis for commercial unitary air conditioners

    SciTech Connect (OSTI)

    Rosenquist, Greg; Coughlin, Katie; Dale, Larry; McMahon, James; Meyers, Steve

    2004-03-31T23:59:59.000Z

    This report describes an analysis of the economic impacts of possible energy efficiency standards for commercial unitary air conditioners and heat pumps on individual customers in terms of two metrics: life-cycle cost (LCC) and payback period (PBP). For each of the two equipment classes considered, the 11.5 EER provides the largest mean LCC savings. The results show how the savings vary among customers facing different electricity prices and other conditions. At 11.5 EER, at least 80% of the users achieve a positive LCC savings. At 12.0 EER, the maximum efficiency analyzed, mean LCC savings are lower but still positive. For the {ge} $65,000 Btu/h to <135,000 Btu/h equipment class, 59% of users achieve a positive LCC savings. For the $135,000 Btu/h to <240,000 Btu/h equipment class, 91% of users achieve a positive LCC savings.

  20. Impact of Charge Degradation on the Life Cycle Climate Performance of a Residential Air-Conditioning System

    SciTech Connect (OSTI)

    Beshr, Mohamed [University of Maryland, College Park; Aute, Vikrant [University of Maryland, College Park; Abdelaziz, Omar [ORNL; Fricke, Brian A [ORNL; Radermacher, Reinhard [University of Maryland, College Park

    2014-01-01T23:59:59.000Z

    Vapor compression systems continuously leak a small fraction of their refrigerant charge to the environment, whether during operation or servicing. As a result of the slow leak rate occurring during operation, the refrigerant charge decreases until the system is serviced and recharged. This charge degradation, after a certain limit, begins to have a detrimental effect on system capacity, energy consumption, and coefficient of performance (COP). This paper presents a literature review and a summary of previous experimental work on the effect of undercharging or charge degradation of different vapor compression systems, especially those without a receiver. These systems include residential air conditioning and heat pump systems utilizing different components and refrigerants, and water chiller systems. Most of these studies show similar trends for the effect of charge degradation on system performance. However, it is found that although much experimental work exists on the effect of charge degradation on system performance, no correlation or comparison between charge degradation and system performance yet exists. Thus, based on the literature review, three different correlations that characterize the effect of charge on system capacity and energy consumption are developed for different systems as follows: one for air-conditioning systems, one for vapor compression water-to-water chiller systems, and one for heat pumps. These correlations can be implemented in vapor compression cycle simulation tools to obtain a better prediction of the system performance throughout its lifetime. In this paper, these correlations are implemented in an open source tool for life cycle climate performance (LCCP) based design of vapor compression systems. The LCCP of a residential air-source heat pump is evaluated using the tool and the effect of charge degradation on the results is studied. The heat pump is simulated using a validated component-based vapor compression system model and the LCCP results obtained using the three charge degradation correlations are compared.

  1. Life Cycle Inventory of a CMOS Chip

    E-Print Network [OSTI]

    Boyd, Sarah; Dornfeld, David; Krishnan, Nikhil

    2006-01-01T23:59:59.000Z

    are shown. Keywords- Life Cycle Assessment (LCA); Life Cycleindustry, and Life Cycle Assessment (LCA) is emerging as a

  2. Economics of Organic Rankine Cycle 

    E-Print Network [OSTI]

    O'Brien, W. J.

    1988-01-01T23:59:59.000Z

    P9int where the composite T-Q curves for a unIt, sys em, or plant have their closest approach) causes increased cooling and increased heating for th total system. Thus heat pumps only make sense when they pump heat from below to above the pi...

  3. Low-pressure-ratio regenerative exhaust-heated gas turbine

    SciTech Connect (OSTI)

    Tampe, L.A.; Frenkel, R.G.; Kowalick, D.J.; Nahatis, H.M.; Silverstein, S.M.; Wilson, D.G.

    1991-01-01T23:59:59.000Z

    A design study of coal-burning gas-turbine engines using the exhaust-heated cycle and state-of-the-art components has been completed. In addition, some initial experiments on a type of rotary ceramic-matrix regenerator that would be used to transfer heat from the products of coal combustion in the hot turbine exhaust to the cool compressed air have been conducted. Highly favorable results have been obtained on all aspects on which definite conclusions could be drawn.

  4. Mechanism and behavior of nucleate boiling heat transfer to the alkalai liquid metals

    E-Print Network [OSTI]

    Deane, Charles William

    1969-01-01T23:59:59.000Z

    A model of boiling heat transfer to the alkali liquid metals is postulated from an examination of the events and phases of the nucleate boiling cycle. The model includes the important effect of microlayer evaporation which ...

  5. Design and Operation of Fluid Beds for Heating, Cooling and Quenching Operations 

    E-Print Network [OSTI]

    Kemp, W. E.

    1981-01-01T23:59:59.000Z

    with austempering cycles have been conducted with excellent results. A unique fluid bed bath which is used for preheating, weld positioning and post-heating of castings has also been produced. Substantial energy and material handling savings have been obtained...

  6. EVALUATION OF A SULFUR OXIDE CHEMICAL HEAT STORAGE PROCESS FOR A STEAM SOLAR ELECTRIC PLANT

    E-Print Network [OSTI]

    Dayan, J.

    2011-01-01T23:59:59.000Z

    System for a Solar Steam Power Plant." 12th Intersoc. Energywith a solar-heated steam power plant during daylight hoursa conventional steam-cycle power plant. for both the power

  7. Regenerator optimization for Stirling cycle refrigeration II

    SciTech Connect (OSTI)

    Colgate, S.A.; Petschek, A.G.

    1994-07-01T23:59:59.000Z

    A cryogenic regenerator for a Stirling cycle is discussed using fractional loss or entropy gain as the criterion of performance. The gas losses are treated separately from heat storage medium losses. We argue that the optimum design corresponds to uniform channel flow with minimum turbulence where the gas velocity and channel width are optimized as a function of gas temperature. The maximization of heat transfer from the gas to the wall and the minimization of entropy production by friction leads to a gas flow velocity equal to sound speed times loss fraction, 1/{sigma}. This velocity and an axial thermal conductivity in the gas leads to a minimum channel width and characteristic length, L=T(dz/dT). A particular scaling of width, W{sup 2} = W{sub o}{sup 2}T{sup 1/2}, and length, L = L{sub o} T{sup {minus}1/2} leads to a design where longitudinal conduction decreases as T{sup 3/2} and the remaining two losses, transverse conduction and friction are equal and constant. The loss fraction, 1/{sigma}, must be made quite small, {approximately}(1/60) in order that the cumulative losses for a large temperature ratio like 300K to 4K, be small enough, like 20% to 40%. This is because half the entropy generated as a loss must be transported first to the cold end before returning to the hot end before being rejected. The dead volume ratio then determines the minimum frequency and with it and the pressure the necessary wall properties. The thermal properties of the channel wall must then accommodate this cyclic heat flow without substantially increasing the loss fraction. This generation of entropy in the walls is derived in terms of the wall heat capacity and thermal conductivity.

  8. HEATING6 verification

    SciTech Connect (OSTI)

    Bryan, C.B.; Childs, K.W.; Giles, G.E.

    1986-12-01T23:59:59.000Z

    The HEATING series of general purpose, finite-difference, conduction heat transfer codes have been in use for many years. During this time the codes have been used extensively, and a general confidence has been developed in regard to their accuracy. However, there has never been a formal verification in a published, citable document. This report documents just such a verification study for the latest code in the HEATING series, HEATING6. This study confirms that HEATING6 is capable of producing accurate results for a large class of heat transfer problems. 11 refs., 170 figs., 82 tabs.

  9. Microfabricated fuel heating value monitoring device

    DOE Patents [OSTI]

    Robinson, Alex L. (Albuquerque, NM); Manginell, Ronald P. (Albuquerque, NM); Moorman, Matthew W. (Albuquerque, NM)

    2010-05-04T23:59:59.000Z

    A microfabricated fuel heating value monitoring device comprises a microfabricated gas chromatography column in combination with a catalytic microcalorimeter. The microcalorimeter can comprise a reference thermal conductivity sensor to provide diagnostics and surety. Using microfabrication techniques, the device can be manufactured in production quantities at a low per-unit cost. The microfabricated fuel heating value monitoring device enables continuous calorimetric determination of the heating value of natural gas with a 1 minute analysis time and 1.5 minute cycle time using air as a carrier gas. This device has applications in remote natural gas mining stations, pipeline switching and metering stations, turbine generators, and other industrial user sites. For gas pipelines, the device can improve gas quality during transfer and blending, and provide accurate financial accounting. For industrial end users, the device can provide continuous feedback of physical gas properties to improve combustion efficiency during use.

  10. Cab Heating and Cooling

    SciTech Connect (OSTI)

    Damman, Dennis

    2005-10-31T23:59:59.000Z

    Schneider National, Inc., SNI, has concluded the Cab Heating and Cooling evaluation of onboard, engine off idling solutions. During the evaluation period three technologies were tested, a Webasto Airtronic diesel fired heater for cold weather operation, and two different approaches to cab cooling in warm weather, a Webasto Parking Cooler, phase change storage system and a Bergstrom Nite System, a 12 volt electrical air conditioning approach to cooling. Diesel fired cab heaters were concluded to provide adequate heat in winter environments down to 10 F. With a targeted idle reduction of 17%, the payback period is under 2 years. The Webasto Parking Cooler demonstrated the viability of this type of technology, but required significant driver involvement to achieve maximum performance. Drivers rated the technology as ''acceptable'', however, in individual discussions it became apparent they were not satisfied with the system limitations in hot weather, (over 85 F). The Bergstrom Nite system was recognized as an improvement by drivers and required less direct driver input to operate. While slightly improved over the Parking Cooler, the hot temperature limitations were only slightly better. Neither the Parking Cooler or the Nite System showed any payback potential at the targeted 17% idle reduction. Fleets who are starting at a higher idle baseline may have a more favorable payback.

  11. Superradiant Quantum Heat Engine

    E-Print Network [OSTI]

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

    2015-03-12T23:59:59.000Z

    Quantum physics has revolutionized the classical disciplines of mechanics, statistical physics, and electrodynamics. It modernized our society with many advances such as lasers and transistors. 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 the quantum regimes. Inevitably, development of quantum heat engines (QHEs) requires investigations of thermodynamical principles from quantum mechanical perspective, and motivates the emerging field of quantum thermodynamics. Studies of QHEs debate on whether quantum coherence can be used as a resource. We explore an alternative that quantum coherence can be a 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 capability of the QHE becomes proportional to the square of the number of the atoms. In addition to practical value of cranking up a QHE, our results reveal a fundamental difference of a quantum fuel from its classical counterpart.

  12. Heat Pump for High School Heat Recovery

    E-Print Network [OSTI]

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

    2006-01-01T23:59:59.000Z

    ) [3] Yayun FAN. Experimental study on a heat pump technology in solar thermal utilization[J]. Acta Energiae Solaris Sinica, Oct.,2002; Vol.23,No.5 ? 581-585.(In Chinese) [4] Nengxi JIANG. Air-conditioning Heat Pump Technology and Its Applications...

  13. Design optimization of conventional heat pumps: application to steady-state heating efficiency

    SciTech Connect (OSTI)

    Rice, C.K.; Fischer, S.K.; Ellison, R.D.; Jackson, W.L.

    1981-01-01T23:59:59.000Z

    A physically-based heat pump model was connected to an optimiztion program to form a computer code for use in the design of high-efficiency heat pumps. The method used allows for the simultaneous optimization of selected design variables, taking proper account of their interactions, while constraining other parameters to chosen limits or fixed values. For optimiztion of the steady-state heating efficiency of conventional heat pumps, ten variables were optimized while heating capacity was fixed; the results may, however, be scaled to other capacities. Calculations were made for a range of component efficiencies and heat exchanger sizes. The results predict substantial improvement in heating performance due to both optimal system configurations and the use of improved components. Sensitivity analyses show that there is considerable latitude for deviating from the optimum design to make use of available component sizes and for accomodating the compromises needed for good cooling performance.

  14. Systems Analyses of Advanced Brayton Cycles

    SciTech Connect (OSTI)

    A.D. Rao; D.J. Francuz; J.D. Maclay; J. Brouwer; A. Verma; M. Li; G.S. Samuelsen

    2008-09-30T23:59:59.000Z

    The main objective is to identify and assess advanced improvements to the Brayton Cycle (such as but not limited to firing temperature, pressure ratio, combustion techniques, intercooling, fuel or combustion air augmentation, enhanced blade cooling schemes) that will lead to significant performance improvements in coal based power systems. This assessment is conducted in the context of conceptual design studies (systems studies) that advance state-of-art Brayton cycles and result in coal based efficiencies equivalent to 65% + on natural gas basis (LHV), or approximately an 8% reduction in heat rate of an IGCC plant utilizing the H class steam cooled gas turbine. H class gas turbines are commercially offered by General Electric and Mitsubishi for natural gas based combined cycle applications with 60% efficiency (LHV) and it is expected that such machine will be offered for syngas applications within the next 10 years. The studies are being sufficiently detailed so that third parties will be able to validate portions or all of the studies. The designs and system studies are based on plants for near zero emissions (including CO{sub 2}). Also included in this program is the performance evaluation of other advanced technologies such as advanced compression concepts and the fuel cell based combined cycle. The objective of the fuel cell based combined cycle task is to identify the desired performance characteristics and design basis for a gas turbine that will be integrated with an SOFC in Integrated Gasification Fuel Cell (IGFC) applications. The goal is the conceptualization of near zero emission (including CO{sub 2} capture) integrated gasification power plants producing electricity as the principle product. The capability of such plants to coproduce H{sub 2} is qualitatively addressed. Since a total systems solution is critical to establishing a plant configuration worthy of a comprehensive market interest, a baseline IGCC plant scheme is developed and used to study how alternative process schemes and power cycles might be used and integrated to achieve higher systems efficiency. To achieve these design results, the total systems approach is taken requiring creative integration of the various process units within the plant. Advanced gas turbine based cycles for Integrated gasification Combined cycle (IGCC) applications are identified by a screening analysis and the more promising cycles recommended for detailed systems analysis. In the case of the IGFC task, the main objective is met by developing a steady-state simulation of the entire plant and then using dynamic simulations of the hybrid Solid Oxide Fuel Cell (SOFC)/Gas Turbine sub-system to investigate the turbo-machinery performance. From these investigations the desired performance characteristics and a basis for design of turbo-machinery for use in a fuel cell gas turbine power block is developed.

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

    Broader source: Energy.gov [DOE]

    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...

  16. What drives glacial cycles

    SciTech Connect (OSTI)

    Broecker, W.S.; Denton, G.H.

    1990-01-01T23:59:59.000Z

    The Milankovitch theory advocates that the glacial cycles have three components: the tilt of the earth's spin axis; the shape of the earth's orbit; and the interaction between the tilt and the eccentricity effects. These three factors work together to vary the amount of sunshine reaching the high northern latitudes in summer and allow the great ice sheets to grow during intervals of cool summers and mild winters. Evidence is presented which indicates that the circulation pattern of the Atlantic ocean was shifted dramatically about 14,000 years ago, at the same time that glaciers in both hemispheres started to retreat. The authors believe that massive reorganizations of the ocean-atmosphere system are the key events that link cyclic changes in the earth's orbit to the advance and retreat of ice sheet.

  17. ABSORPTION HEAT PUMP IN THE DISTRICT HEATING

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    · decrease of the CO2 emission - 1580 quotas · installation of closed cycle cooling circuits · decrease Lower operational costs Extra electricity costs Steam from already existing steam boiler More working

  18. Visible light plasmonic heating of Au-ZnO for the catalytic reduction of CO{sub 2}

    SciTech Connect (OSTI)

    Wang, Congjun; Ranasingha, Oshadha; Natesakhawat, Sittichai; Ohodnicki, Paul R.; Ohodnicki, Andio, Mark; Lewis, James; P Matranga, Christopher

    2013-05-01T23:59:59.000Z

    Plasmonic excitation of Au nanoparticles attached to the surface of ZnO catalysts using low power 532 nm laser illumination leads to significant heating of the catalyst and the conversion of CO{sub 2} and H{sub 2} reactants to CH{sub 4} and CO products. Temperature-calibrated Raman spectra of ZnO phonons show that intensity-dependent plasmonic excitation can controllably heat Au–ZnO from 30 to #1;~600 {degrees}#3;C and simultaneously tune the CH{sub 4} : CO product ratio. The laser induced heating and resulting CH{sub 4} : CO product distribution agrees well with predictions from thermodynamic models and temperatureprogrammed reaction experiments indicating that the reaction is a thermally driven process resulting from the plasmonic heating of the Au–ZnO. The apparent quantum yield for CO{sub 2} conversion under continuous wave (cw) 532 nm laser illumination is 0.030%. The Au–ZnO catalysts are robust and remain active after repeated laser exposure and cycling. The light intensity required to initiate CO{sub 2} reduction is low (#1;~2.5 x#4; 10{sup 5} W m{sup #5;-2}) and achievable with solar concentrators. Our results illustrate the viability of plasmonic heating approaches for CO{sub 2} utilization and other practical thermal catalytic applications.

  19. Thermionic-combustor combined-cycle system. Volume III. A thermionic converter design for gas-turbine combined-cycle systems

    SciTech Connect (OSTI)

    Fitzpatrick, G.O.; Britt, E.J.; Dick, R.S. Jr.

    1981-05-01T23:59:59.000Z

    Thermionic converter design is strongly influenced by the configuration of the heat source and heat sink. These two externally imposed conditions are of major importance in arriving at a viable converter design. In addition to these two factors, the economical and reliable transfer of energy internally within the converter is another major item in the design. The effects of the engineering trade-offs made in arriving at the design chosen for the Gas Turbine Combined Cycle combustor are reviewed.

  20. Recycling and Life Cycle Issues

    SciTech Connect (OSTI)

    Das, Sujit [ORNL

    2010-01-01T23:59:59.000Z

    This chapter addresses recycling and life cycle considerations related to the growing use of lightweight materials in vehicles. The chapter first addresses the benefit of a life cycle perspective in materials choice, and the role that recycling plays in reducing energy inputs and environmental impacts in a vehicle s life cycle. Some limitations of life cycle analysis and results of several vehicle- and fleet-level assessments are drawn from published studies. With emphasis on lightweight materials such as aluminum, magnesium, and polymer composites, the status of the existing recycling infrastructure and technological challenges being faced by the industry also are discussed.

  1. Glacial cycles and astronomical forcing

    SciTech Connect (OSTI)

    Muller, R.A. [Lawrence Berkeley Lab., CA (United States)] [Lawrence Berkeley Lab., CA (United States); MacDonald, G.J. [International Institute for Applied Systems Analysis, Laxenburg (Austria)] [International Institute for Applied Systems Analysis, Laxenburg (Austria)

    1997-07-11T23:59:59.000Z

    Narrow spectral features in ocean sediment records offer strong evidence that the cycles of glaciation were driven by astronomical forces. Two million years ago, the cycles match the 41,000-year period of Earth`s obliquity. This supports the Croll/Milankovitch theory, which attributes the cycles to variations in insolation. But for the past million years, the spectrum is dominated by a single 100,000-year feature and is a poor match to the predictions of insolation models. The spectrum can be accounted for by a theory that derives the cycles of glaciation from variations in the inclination of Earth`s orbital plane.

  2. Methodology of CO{sub 2} emission evaluation in the life cycle of office building facades

    SciTech Connect (OSTI)

    Taborianski, Vanessa Montoro; Prado, Racine T.A., E-mail: racine.prado@poli.usp.br

    2012-02-15T23:59:59.000Z

    The construction industry is one of the greatest sources of pollution because of the high level of energy consumption during its life cycle. In addition to using energy while constructing a building, several systems also use power while the building is operating, especially the air-conditioning system. Energy consumption for this system is related, among other issues, to external air temperature and the required internal temperature of the building. The facades are elements which present the highest level of ambient heat transfer from the outside to the inside of tall buildings. Thus, the type of facade has an influence on energy consumption during the building life cycle and, consequently, contributes to buildings' CO{sub 2} emissions, because these emissions are directly connected to energy consumption. Therefore, the aim is to help develop a methodology for evaluating CO{sub 2} emissions generated during the life cycle of office building facades. The results, based on the parameters used in this study, show that facades using structural glazing and uncolored glass emit the most CO{sub 2} throughout their life cycle, followed by brick facades covered with compound aluminum panels or ACM (Aluminum Composite Material), facades using structural glazing and reflective glass and brick facades with plaster coating. On the other hand, the typology of facade that emits less CO{sub 2} is brickwork and mortar because its thermal barrier is better than structural glazing facade and materials used to produce this facade are better than brickwork and ACM. Finally, an uncertainty analysis was conducted to verify the accuracy of the results attained. - Highlights: Black-Right-Pointing-Pointer We develop a methodology for evaluating CO{sub 2} emissions generated during the life cycle of office building facades. Black-Right-Pointing-Pointer This methodology is based in LCA. Black-Right-Pointing-Pointer We use an uncertainty analysis to verify the accuracy of the results attained. Black-Right-Pointing-Pointer We study three typologies of facades. Black-Right-Pointing-Pointer Facades using structural glazing and uncolored glass emit the most CO{sub 2} throughout their life cycle.

  3. Photovoltaic roof heat flux

    E-Print Network [OSTI]

    Samady, Mezhgan Frishta

    2011-01-01T23:59:59.000Z

    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

  4. DistrictHeating Nuevasaladecalderasydistribucin

    E-Print Network [OSTI]

    Fraguela, Basilio B.

    DistrictHeating Nuevasaladecalderasydistribución decaloreneláreauniversitariade AZapateira Jesús, difusión. DISTRICT HEATING O CALEFACCIÓN DE BARRIO #12;MATERIALIZACIÓN INTEGRACIÓN VISUAL DE ELEMENTOS rendimiento global de la instalación. - Contabilización de pérdidas en tuberías de distribución. #12;DISTRICT

  5. HEAT TRANSFER FLUIDS

    E-Print Network [OSTI]

    Lenert, Andrej

    2012-01-01T23:59:59.000Z

    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 ...

  6. Stirling cycle piston and valving method

    SciTech Connect (OSTI)

    Mitchell, M.P.; Bauwens, L.

    1990-05-22T23:59:59.000Z

    This patent describes a device of the Stirling cycle type for converting energy between heat and work. It comprises: compression and expansion chambers, means for decreasing the volume of one of the chambers while increasing the volume of the other chamber, gas storage means comprising first and second regenerator means, each connected to the expansion chamber and to the compression chamber, a quantity of compressible gas confined for circulation through the chambers and gas storage means, control means for communicating the first regenerator means only to the expansion chamber while communicating the second regenerator means only to the compression chamber and subsequently communicating the second regenerator means only to the expansion chamber while communicating the first regenerator means only to the compression chamber with intermediate steps of closing one of the regenerator means while exchanging fluid between the chambers through the other regenerator means.

  7. Multivariable cycle-to-cycle of an injection molding process

    E-Print Network [OSTI]

    Vanderpuije, Curtis N

    2005-01-01T23:59:59.000Z

    Cycle-to-Cycle (CtC) feedback control has been studied extensively with increasing demands on the precision and quality of manufactured parts. Single input-Single output has been studied as the basis of CtC feedback control. ...

  8. 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.

  9. Abrasion resistant heat pipe

    DOE Patents [OSTI]

    Ernst, Donald M. (Leola, PA)

    1984-10-23T23:59:59.000Z

    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.

  10. Solar heat receiver

    DOE Patents [OSTI]

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

    1985-01-01T23:59:59.000Z

    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.

  11. Solar heat receiver

    DOE Patents [OSTI]

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

    1982-09-29T23:59:59.000Z

    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.

  12. Industrial Waste Heat Recovery

    E-Print Network [OSTI]

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

    1980-01-01T23:59:59.000Z

    INDUSTRIAL WASTE HEAT RECOVREY M. E. Ward and N. G. Solomon E. S. Tabb Solar Turbines International and Gas Research Institute San Diego, California Chicago, Illinois ABSTRACT i I One hundred fifty reports were reviewed along with interviews... tests, promising low temperature heat exchanger tube alloys and coated surfaces were identified. 1INTROUCTION of advanced technology heat recovery techniques 1_ Recovering waste heat from the flue gases of the pr~ary objective. Specific objectives...

  13. A corrosive resistant heat exchanger

    DOE Patents [OSTI]

    Richlen, S.L.

    1987-08-10T23:59:59.000Z

    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.

  14. INTEGRATED PYROLYSIS COMBINED CYCLE BIOMASS POWER SYSTEM CONCEPT DEFINITION

    SciTech Connect (OSTI)

    Eric Sandvig; Gary Walling; Robert C. Brown; Ryan Pletka; Desmond Radlein; Warren Johnson

    2003-03-01T23:59:59.000Z

    Advanced power systems based on integrated gasification/combined cycles (IGCC) are often presented as a solution to the present shortcomings of biomass as fuel. Although IGCC has been technically demonstrated at full scale, it has not been adopted for commercial power generation. Part of the reason for this situation is the continuing low price for coal. However, another significant barrier to IGCC is the high level of integration of this technology: the gas output from the gasifier must be perfectly matched to the energy demand of the gas turbine cycle. We are developing an alternative to IGCC for biomass power: the integrated (fast) pyrolysis/ combined cycle (IPCC). In this system solid biomass is converted into liquid rather than gaseous fuel. This liquid fuel, called bio-oil, is a mixture of oxygenated organic compounds and water that serves as fuel for a gas turbine topping cycle. Waste heat from the gas turbine provides thermal energy to the steam turbine bottoming cycle. Advantages of the biomass-fueled IPCC system include: combined cycle efficiency exceeding 37 percent efficiency for a system as small as 7.6 MW{sub e}; absence of high pressure thermal reactors; decoupling of fuel processing and power generation; and opportunities for recovering value-added products from the bio-oil. This report provides a technical overview of the system including pyrolyzer design, fuel clean-up strategies, pyrolysate condenser design, opportunities for recovering pyrolysis byproducts, gas turbine cycle design, and Rankine steam cycle. The report also reviews the potential biomass fuel supply in Iowa, provide and economic analysis, and present a summery of benefits from the proposed system.

  15. The cause of the weak solar cycle 24

    E-Print Network [OSTI]

    Jiang, Jie; Schuessler, Manfred

    2015-01-01T23:59:59.000Z

    The ongoing 11-year cycle of solar activity is considerably less vigorous than the three cycles before. It was preceded by a very deep activity minimum with a low polar magnetic flux, the source of the toroidal field responsible for solar magnetic activity in the subsequent cycle. Simulation of the evolution of the solar surface field shows that the weak polar fields and thus the weakness of the present cycle 24 are mainly caused by a number of bigger bipolar regions emerging at low latitudes with a `wrong' (i.e., opposite to the majority for this cycle) orientation of their magnetic polarities in the North-South direction, which impaired the growth of the polar field. These regions had a particularly strong effect since they emerged within $\\pm10^\\circ$ latitude from the solar equator.

  16. Acoustic Heating Peter Ulmschneider

    E-Print Network [OSTI]

    Ulmschneider, Peter

    mechanisms. 1. The acoustic heating theory Only a few years after Edlen's (1941) discovery that the solar acoustic wave radiation- · b. field acoustic wave Figure 1. Panel a: Acoustic heating in late-type stars: effective temperature TeJ f, gravity g and mixing length parameter fr. Panel b: Acoustic heating in early

  17. 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

  18. 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.

  19. Liquid heat capacity lasers

    DOE Patents [OSTI]

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

    2007-05-01T23:59:59.000Z

    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. Application Study of a Single House Horizontal Heating System 

    E-Print Network [OSTI]

    Hang, Y.; Ying, D.

    2006-01-01T23:59:59.000Z

    the different forms of heating systems suited for single household metering. We introduce especially the single house horizontal spanning system and show how to select the heat flow rate of the radiator. We also study the distribution rule of the heat...

  1. Thermoeconomic Analysis of a Solar Heat-Pump System 

    E-Print Network [OSTI]

    Gao, Y.; Wang, S.

    2006-01-01T23:59:59.000Z

    This paper introduces a solar energy heat-pump system and analyzes the thermoeconomics. The results show that the solar energy heat-pump system can be operated in different modes and used for room heating in winter and cooling in summer and...

  2. Thermoeconomic Analysis of a Solar Heat-Pump System

    E-Print Network [OSTI]

    Gao, Y.; Wang, S.

    2006-01-01T23:59:59.000Z

    This paper introduces a solar energy heat-pump system and analyzes the thermoeconomics. The results show that the solar energy heat-pump system can be operated in different modes and used for room heating in winter and cooling in summer and...

  3. Integrated supercritical water gasification combined cycle (IGCC) systems for improved performance and reduced operating costs in existing plants

    SciTech Connect (OSTI)

    Tolman, R.; Parkinson, W.J.

    1999-07-01T23:59:59.000Z

    A revolutionary hydrothermal heat recovery steam generator (HRSG) is being developed to produce clean fuels for gas turbines from slurries and emulsions of opportunity fuels. Water can be above 80% by weight and solids below 20%, including coal fines, coal water fuels, biomass, composted municipal refuse, sewage sludge and bitumen/Orimulsion. The patented HRSG tubes use a commercial method of particle scrubbing to improve heat transfer and prevent corrosion and deposition on heat transfer surfaces. A continuous-flow pilot plant is planned to test the HRSG over a wide range of operating conditions, including the supercritical conditions of water, above 221 bar (3,205 psia) and 374 C (705 F). Bench scale data shows, that supercritical water gasification below 580 C (1,076 F) and low residence time without catalysts or an oxidizer can produce a char product that can contain carbon up to the amount of fixed carbon in the proximate analysis of the solids in the feed. This char can be burned with coal in an existing combustion system to provide the heat required for gasification. The new HRSG tubes can be retrofitted into existing power plant boilers for repowering of existing plants for improved performance and reduced costs. A special condensing turbine allows final low-temperature cleaning and maintains quality and combustibility of the fuel vapor for modern gas turbine in the new Vapor Transmission Cycle (VTC). Increased power output and efficiency can be provided for existing plants, while reducing fuel costs. A preliminary computer-based process simulation model has been prepared that includes material and energy balances that simulate commercial-scale operations of the VTC on sewage sludge and coal. Results predict over 40% HHV thermal efficiency to electric power from sewage sludge at more than 83% water by weight. The system appears to become autothermal (no supplemental fuel required) at about 35% fixed carbon in the feed. Thus, bituminous and lignite coal slurries could be gasified at less than 25% coal and more than 75% water. Preliminary life cycle cost analyses indicate that disposal fees for sewage sludge improve operating economics over fuel that must be purchased, the cost and schedule advantages of natural gas-fired combined cycle systems are preserved. Sensitivity analyses show that increasing capital costs by 50% can be offset by an increase in sewage sludge disposal fees of $10/metric ton.

  4. Testing of a Stirling cycle cooler

    SciTech Connect (OSTI)

    Chen, F.C.; Keshock, E.G.; Murphy, R.W.

    1988-09-01T23:59:59.000Z

    Stirling cycle coolers have long been used as low temperature refrigeration devices. They are relatively compact, reliable, commercially available, and use helium as the working fluid. The Stirling cycle, in principle, can be used for household refrigeration and heat pumping applications as well. Currently, these applications are almost entirely provided by the vapor compression technology using chlorofluorocarbons (CFCs) as working fluids. It has been known that CFCs cause depletion of the ozone layer that protects the earth against harmful levels of ultraviolet radiation from the sun. A recent report of a ''hole'' in the ozone layer above Antarctica and of possible environmental and health consequences from ozone depletion aroused public attention. The urgent need to reduce the future used of CFCs should instigate investigation of non-CFC alternative technologies. The Stirling cooler technology, which does not use CFCs, could be a viable alternative. A laboratory test of the performance of a Stirling cooler is reported and its implications for household refrigeration are explored. 11 refs., 6 figs., 2 tabs.

  5. MODELING HORMONAL CONTROL MENSTRUAL CYCLE

    E-Print Network [OSTI]

    MODELING HORMONAL CONTROL OF THE MENSTRUAL CYCLE James F. Selgrade Department of Mathematics of five hormones important for regulation and maintenance of the menstrual cycle. Models which correctly@math.ncsu.edu Abstract This study presents a strategy for developing a mathematical model describing the concentrations

  6. Nuclear fuel cycle information workshop

    SciTech Connect (OSTI)

    Not Available

    1983-01-01T23:59:59.000Z

    This overview of the nuclear fuel cycle is divided into three parts. First, is a brief discussion of the basic principles of how nuclear reactors work; second, is a look at the major types of nuclear reactors being used and world-wide nuclear capacity; and third, is an overview of the nuclear fuel cycle and the present industrial capability in the US.

  7. Prediction of Sunspot Cycles by Data Assimilation Method

    E-Print Network [OSTI]

    I. N. Kitiashvili; A. G. Kosovichev

    2009-02-11T23:59:59.000Z

    Despite the known general properties of the solar cycles, a reliable forecast of the 11-year sunspot number variations is still a problem. The difficulties are caused by the apparent chaotic behavior of the sunspot numbers from cycle to cycle and by the influence of various turbulent dynamo processes, which are far from understanding. For predicting the solar cycle properties we make an initial attempt to use the Ensemble Kalman Filter (EnKF), a data assimilation method, which takes into account uncertainties of a dynamo model and measurements, and allows to estimate future observational data. We present the results of forecasting of the solar cycles obtained by the EnKF method in application to a low-mode nonlinear dynamical system modeling the solar $\\alpha\\Omega$-dynamo process with variable magnetic helicity. Calculations of the predictions for the previous sunspot cycles show a reasonable agreement with the actual data. This forecast model predicts that the next sunspot cycle will be significantly weaker (by $\\sim 30%$) than the previous cycle, continuing the trend of low solar activity.

  8. Industrial Process Heat Pumps--Some Unconventional Wisdom

    E-Print Network [OSTI]

    Karp, A.

    to be incorrect and/or i.llusory. Similar situa tions were uncovered in other industries as part of an EPRI-funded pinch analysis by Union Carbide of heat-pumped evaporators in ten processes.(12) Figure 8 from that study shows that heat pumping applications... additional design insights important to the heat pump I s cost effec tiveness. Figure 9. also from the EPRI study. shows how heat pump sizing can be limited to that which is truly useful. taking into account other process heat integration possibilities...

  9. Life Cycle Asset Management

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1998-10-14T23:59:59.000Z

    (The following directives are deleted or consolidated into this Order and shall be phased out as noted in Paragraph 2: DOE 1332.1A; DOE 4010.1A; DOE 4300.1C; DOE 4320.1B; DOE 4320.2A; DOE 4330.4B; DOE 4330.5; DOE 4540.1C; DOE 4700.1). This Order supersedes specific project management provisions within DOE O 430.1A, LIFE CYCLE ASSET MANAGEMENT. The specific paragraphs canceled by this Order are 6e(7); 7a(3); 7b(11) and (14); 7c(4),(6),(7),(11), and (16); 7d(4) and (8); 7e(3),(10), and (17); Attachment 1, Definitions (item 30 - Line Item Project, item 42 - Project, item 48 - Strategic System); and Attachment 2, Contractor Requirements Document (paragraph 1d regarding a project management system). The remainder of DOE O 430.1A remains in effect. Cancels DOE O 430.1. Canceled by DOE O 413.3.

  10. Heat pump apparatus

    DOE Patents [OSTI]

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

    1983-01-01T23:59:59.000Z

    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.

  11. 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

    2001-01-01T23:59:59.000Z

    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.

  12. Advanced heat pump for the recovery of volatile organic compounds

    SciTech Connect (OSTI)

    Not Available

    1992-03-01T23:59:59.000Z

    Emissions of Volatile Organic Compounds (VOC) from stationary industrial and commercial sources represent a substantial portion of the total US VOC emissions. The Toxic-Release Inventory'' of The US Environmental Protection Agency estimates this to be at about 3 billion pounds per year (1987 estimates). The majority of these VOC emissions are from coating processes, cleaning processes, polymer production, fuel production and distribution, foam blowing,refrigerant production, and wood products production. The US Department of Energy's (DOE) interest in the recovery of VOC stems from the energy embodied in the recovered solvents and the energy required to dispose of them in an environmentally acceptable manner. This Phase I report documents 3M's work in close working relationship with its subcontractor Nuclear Consulting Services (Nucon) for the preliminary conceptual design of an advanced Brayton cycle heat pump for the recovery of VOC. Nucon designed Brayton cycle heat pump for the recovery of methyl ethyl ketone and toluene from coating operations at 3M Weatherford, OK, was used as a base line for the work under cooperative agreement between 3M and ODE. See appendix A and reference (4) by Kovach of Nucon. This cooperative agreement report evaluates and compares an advanced Brayton cycle heat pump for solvent recovery with other competing technologies for solvent recovery and reuse. This advanced Brayton cycle heat pump is simple (very few components), highly reliable (off the shelf components), energy efficient and economically priced.

  13. Technical Note Solution of periodic heating problems by the

    E-Print Network [OSTI]

    Barber, James R.

    , the valves of an internal combustion engine experience direct heating from the combusting gases, cooling from numerical simulation of every cycle. It also permits a direct solution for the nodal temperatures-dimensional) examples and the obvious way to proceed is to use numerical simulation [5] ± i.e., to step in time solving

  14. Solar High Temperature Water-Splitting Cycle with Quantum Boost

    SciTech Connect (OSTI)

    Taylor, Robin [SAIC] [SAIC; Davenport, Roger [SAIC] [SAIC; Talbot, Jan [UCSD] [UCSD; Herz, Richard [UCSD] [UCSD; Genders, David [Electrosynthesis Co.] [Electrosynthesis Co.; Symons, Peter [Electrosynthesis Co.] [Electrosynthesis Co.; Brown, Lloyd [TChemE] [TChemE

    2014-04-25T23:59:59.000Z

    A sulfur family chemical cycle having ammonia as the working fluid and reagent was developed as a cost-effective and efficient hydrogen production technology based on a solar thermochemical water-splitting cycle. The sulfur ammonia (SA) cycle is a renewable and sustainable process that is unique in that it is an all-fluid cycle (i.e., with no solids handling). It uses a moderate temperature solar plant with the solar receiver operating at 800°C. All electricity needed is generated internally from recovered heat. The plant would operate continuously with low cost storage and it is a good potential solar thermochemical hydrogen production cycle for reaching the DOE cost goals. Two approaches were considered for the hydrogen production step of the SA cycle: (1) photocatalytic, and (2) electrolytic oxidation of ammonium sulfite to ammonium sulfate in aqueous solutions. Also, two sub-cycles were evaluated for the oxygen evolution side of the SA cycle: (1) zinc sulfate/zinc oxide, and (2) potassium sulfate/potassium pyrosulfate. The laboratory testing and optimization of all the process steps for each version of the SA cycle were proven in the laboratory or have been fully demonstrated by others, but further optimization is still possible and needed. The solar configuration evolved to a 50 MW(thermal) central receiver system with a North heliostat field, a cavity receiver, and NaCl molten salt storage to allow continuous operation. The H2A economic model was used to optimize and trade-off SA cycle configurations. Parametric studies of chemical plant performance have indicated process efficiencies of ~20%. Although the current process efficiency is technically acceptable, an increased efficiency is needed if the DOE cost targets are to be reached. There are two interrelated areas in which there is the potential for significant efficiency improvements: electrolysis cell voltage and excessive water vaporization. Methods to significantly reduce water evaporation are proposed for future activities. Electrolysis membranes that permit higher temperatures and lower voltages are attainable. The oxygen half cycle will need further development and improvement.

  15. Ageing of a granular pile induced by thermal cycling

    E-Print Network [OSTI]

    Thibaut Divoux; Ion Vassilief; Hervé Gayvallet; Jean-Christophe Géminard

    2009-06-02T23:59:59.000Z

    Here we show that variations of temperature, even of a few degrees in amplitude, induce the ageing of a granular pile. In particular, we report measurements of physical properties of a granular heap submitted to thermal cycles. Namely, we focus on the evolution of the thermal linear-expansion coefficient and of the thermal conductivity of the pile with the number of cycles. The present contribution nicely supplements a recent article we published elsewhere [Phys. Rev. Lett. \\textbf{101}, 148303 (2008)] and introduces a different and promising method to impose temperature cycles to a granular pile.

  16. TRACKING THE LIFE CYCLE OF CONSTRUCTION STEEL: THE DEVELOPMENT OF A RESOURCE LOOP

    E-Print Network [OSTI]

    Liu, Lanfang

    2009-12-17T23:59:59.000Z

    product have in its life span and how each material flows along with a product’s life cycle. At each stage, there are always materials flowing in or flow out of products’ life cycles. Materials could be chemicals, raw materials, fossil fuels... production Loss in fuel conversion at power plants Transmission and distribution losses Fuel extraction, processing and delivery Energy consumption delivering fuel for use in power plants, transport equipment and industrial plants Process heat Fuel...

  17. Feasibility Study of Secondary Heat Exchanger Concepts for the Advanced High Temperature Reactor

    SciTech Connect (OSTI)

    Piyush Sabharwall

    2011-09-01T23:59:59.000Z

    The work reported herein represents a significant step in the preliminary design of heat exchanger options (material options, thermal design, selection and evaluation methodology with existing challenges). The primary purpose of this study is to aid in the development and selection of the required heat exchanger for power production using either a subcritical or supercritical Rankine cycle.

  18. Optimal Operation of Finite-time Tricycles with Heat Conduction Losses Raj K. Pathria

    E-Print Network [OSTI]

    Salamon, Peter

    -principle limits to the finite-time operation of a cycling working fluid acting as an agent in the transfer of heat of Curzon and Ahlborn for the efficiency of a Carnot-like heat engine at maximu m power. PACS: 05.70.Ln, 05 means "internall y reversible" and allows us to treat the subsystems participating in a process as being

  19. VAPOR COMPRESSION HEAT PUMP SYSTEM FIELD TESTS AT THE TECH COMPLEX

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    include the Annual Cycle Energy System (ACES), solar assisted heat pumps (SAHP) both parallel and series and may well be the most efficient alternative for residences in cold climates. INTRODUCTION A heat pump. Baxter, Energy Division, N8 O Oak Ridge National Laboratory37831 Ridge, Tennessee 37831 WI ' ABSTRACT

  20. Simulating heat transport of harmonic temperature signals in the Earth's shallow subsurface: Lower-boundary sensitivities

    E-Print Network [OSTI]

    Smerdon, Jason E.

    Simulating heat transport of harmonic temperature signals in the Earth's shallow subsurface: Lower changes, freeze-thaw cycles, and hydrologic dynamics. It is uncertain, however, whether the reported atmospheric simulations. Citation: Smerdon, J. E., and M. Stieglitz (2006), Simulating heat transport

  1. Optimized nuclear and solar dynamic organic Rankine cycles for Space Station applications

    E-Print Network [OSTI]

    Eubanks, Dana Len

    1988-01-01T23:59:59.000Z

    the power conver- sion scheme without a regenerative heat exchanger). In the process of finding the state points, a set of property data lookup functions are called. Around this framework of a thermodynamic cycle, with or without a regen- erator... regenerative heat exchanger state 9 state 6 feed ump Fig. 7. Organic Rankine Cycle Schematic including Numbered State Points. 1000 900 800 700 600 500 I dc 400 Cd CL E 300 Cp 200 12PP -1000 -800 -600 -400 -200 0 200 400 600 800 relative...

  2. 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

  3. Analysis of radial fin assembly heat transfer with dehumidification

    SciTech Connect (OSTI)

    Rosario, L.; Rahman, M.M. [Univ. of South Florida, Tampa, FL (United States). Dept. of Mechanical Engineering

    1996-12-31T23:59:59.000Z

    The aim of this paper is the analysis of heat transfer in a radial fin assembly during the process of dehumidification. An individual finned tube geometry is a reasonable representation of heat exchangers used in air conditioning. The condensation process involves both heat and mass transfer and the cooling takes place by the removal of sensible as well as latent heat. The ratio of sensible to total heat is an important quantity that defines the heat transfer process during a dehumidifier operation. A one-dimensional model for heat transfer in the fin and the heat exchanger block is developed to study the effects of condensation on the fin surface. The combined heat and mass transfer process is modeled by incorporating the ratio of sensible to total heat in the formulation. The augmentation of heat transfer due to fin was established by comparing heat transfer rate with and without fins under the same operating conditions. Numerical calculations were carried out to study the effects of relative humidity and dry bulb temperature of the incoming air, and cold fluid temperature inside the coil on the performance of the heat exchanger. Results were compared to those published for rectangular fin under humid condition showed excellent agreement when the present model was used to compute that limiting condition. It was found that the heat transfer rate increased with increment in both dry bulb temperature and relative humidity of the air. The augmentation factor, however, decreased with increment in relative humidity and the dry bulb temperature.

  4. Potential market analysis for residential solar assisted in-line heat pumps

    SciTech Connect (OSTI)

    Not Available

    1981-01-01T23:59:59.000Z

    The method of studying the performance of the solar-assisted heat pump using the FCHART 4.0 computer program is described. The solar-assisted heat pump's performance was compared to that of an air-to-air heat pump and found to be inferior. The lifetime energy requirement is expected to be greater, as is its life-cycle cost. Moreover, conventional heat pumps are available now and are more easily suited to retrofit applications. It is recommended that the solar-assisted heat pump program be terminated in favor of more identifiable significant residential energy programs. (LEW)

  5. Optimization of Heat Exchangers

    SciTech Connect (OSTI)

    Ivan Catton

    2010-10-01T23:59:59.000Z

    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.

  6. Heat pump system

    DOE Patents [OSTI]

    Swenson, Paul F.; Moore, Paul B.

    1983-06-21T23:59:59.000Z

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

  7. Heat pump system

    DOE Patents [OSTI]

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

    1983-01-01T23:59:59.000Z

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

  8. Do Heat Pump Clothes Dryers Make Sense for the U.S. Market

    SciTech Connect (OSTI)

    Meyers, Steve; Franco, Victor; Lekov, Alex; Thompson, Lisa; Sturges, Andy

    2010-05-14T23:59:59.000Z

    Heat pump clothes dryers (HPCDs) can be as much as 50percent more energy-efficient than conventional electric resistance clothes dryers, and therefore have the potential to save substantial amounts of electricity. While not currently available in the U.S., there are manufacturers in Europe and Japan that produce units for those markets. Drawing on analysis conducted for the U.S. Department of Energy's (DOE) current rulemaking on amended standards for clothes dryers, this paper evaluates the cost-effectiveness of HPCDs in American homes, as well as the national impact analysis for different market share scenarios. In order to get an accurate measurement of real energy savings potential, the paper offers a new energy use calculation methodology that takes into account the most current data on clothes washer cycles, clothes dryer usage frequency, remaining moisture content, and load weight per cycle, which is very different from current test procedure values. Using the above methodology along with product cost estimates developed by DOE, the paper presents the results of a life-cycle cost analysis of the adoption of HPCDs in a representative sample of American homes. The results show that HPCDs have positive economic benefits only for households with high clothes dryer usage or for households with high electricity prices and moderately high utilization.

  9. Cyclic process for producing methane in a tubular reactor with effective heat removal

    DOE Patents [OSTI]

    Frost, Albert C. (Congers, NY); Yang, Chang-Lee (Spring Valley, NY)

    1986-01-01T23:59:59.000Z

    Carbon monoxide-containing gas streams are converted to methane by a cyclic, essentially two-step process in which said carbon monoxide is disproportionated to form carbon dioxide and active surface carbon deposited on the surface of a catalyst, and said carbon is reacted with steam to form product methane and by-product carbon dioxide. The exothermic heat of reaction generated in each step is effectively removed during each complete cycle so as to avoid a build up of heat from cycle-to-cycle, with particularly advantageous techniques being employed for fixed bed, tubular and fluidized bed reactor operations.

  10. Cyclic process for producing methane from carbon monoxide with heat removal

    DOE Patents [OSTI]

    Frost, Albert C. (Congers, NY); Yang, Chang-lee (Spring Valley, NY)

    1982-01-01T23:59:59.000Z

    Carbon monoxide-containing gas streams are converted to methane by a cyclic, essentially two-step process in which said carbon monoxide is disproportionated to form carbon dioxide and active surface carbon deposited on the surface of a catalyst, and said carbon is reacted with steam to form product methane and by-product carbon dioxide. The exothermic heat of reaction generated in each step is effectively removed during each complete cycle so as to avoid a build up of heat from cycle-to-cycle, with particularly advantageous techniques being employed for fixed bed, tubular and fluidized bed reactor operations.

  11. Comparative evaluation of the impacts of domestic gas and electric heat pump heating on air pollution in California. Final report

    SciTech Connect (OSTI)

    Ganji, A. [San Francisco State Univ., CA (United States). Div. of Engineering

    1992-07-01T23:59:59.000Z

    Residential space and water heating accounts for approximately 12% of California`s and 15% of the United States, energy consumption. most Of the residential heating is by direct use of natural gas. combustion of natural gas is a contributor to the overall air pollution,, especially CO and NO{sub x} in the urban areas. Another efficient method for domestic water and space heating is use of electric heat pumps, the most popular category of which uses air as its heat source. Electric heat pumps do not emit air pollutants at the point of use, but use electric power, which is a major contributor to air pollution at its point of generation from fossil fuels. It is the specific objective of this report to evaluate and compare the energy efficiency and source air pollutants of natural gas heaters and electric heat pumps used for domestic heating. Effect of replacing natural gas heaters with electric heat pumps on air pollutant emissions due to domestic heating in two urban areas and in California as a whole has also been evaluated. The analysis shows that with the present state of technology, electric heat pumps have higher heating efficiencies than natural gas heaters. Considering the current electricity generation mix in the US, electric heat pumps produce two to four times more NO{sub x}, much less CO, and comparable amount of CO{sub 2} per unit of useful heating energy compared to natural gas heaters. With California mix, electric heat pumps produce comparable NO{sub x} and much less CO and approximately 30% less CO{sub 2} per unit heat output. Replacement of natural gas heaters with electric heat pumps will slightly increase the overall NO{sub x}, and reduce CO and CO{sub 2} emissions in California. The effect of advanced technology power generation and heat pump heating has also been analyzed.

  12. Comparative evaluation of the impacts of domestic gas and electric heat pump heating on air pollution in California

    SciTech Connect (OSTI)

    Ganji, A. (San Francisco State Univ., CA (United States). Div. of Engineering)

    1992-07-01T23:59:59.000Z

    Residential space and water heating accounts for approximately 12% of California's and 15% of the United States, energy consumption. most Of the residential heating is by direct use of natural gas. combustion of natural gas is a contributor to the overall air pollution,, especially CO and NO{sub x} in the urban areas. Another efficient method for domestic water and space heating is use of electric heat pumps, the most popular category of which uses air as its heat source. Electric heat pumps do not emit air pollutants at the point of use, but use electric power, which is a major contributor to air pollution at its point of generation from fossil fuels. It is the specific objective of this report to evaluate and compare the energy efficiency and source air pollutants of natural gas heaters and electric heat pumps used for domestic heating. Effect of replacing natural gas heaters with electric heat pumps on air pollutant emissions due to domestic heating in two urban areas and in California as a whole has also been evaluated. The analysis shows that with the present state of technology, electric heat pumps have higher heating efficiencies than natural gas heaters. Considering the current electricity generation mix in the US, electric heat pumps produce two to four times more NO{sub x}, much less CO, and comparable amount of CO{sub 2} per unit of useful heating energy compared to natural gas heaters. With California mix, electric heat pumps produce comparable NO{sub x} and much less CO and approximately 30% less CO{sub 2} per unit heat output. Replacement of natural gas heaters with electric heat pumps will slightly increase the overall NO{sub x}, and reduce CO and CO{sub 2} emissions in California. The effect of advanced technology power generation and heat pump heating has also been analyzed.

  13. Fluidized bed heat treating system

    DOE Patents [OSTI]

    Ripley, Edward B; Pfennigwerth, Glenn L

    2014-05-06T23:59:59.000Z

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

  14. Summer HeatSummer Heat Heat stress solutions

    E-Print Network [OSTI]

    Liskiewicz, Maciej

    occur (then drink a lightly salted beverage like a sports drink). The water's temperature should be cool How should gardeners avoid becoming a safety threat to themselves and others when it's hot? Start to the heat. Become a weather watcher. Set up a small weather station (with a high/low thermom eter, rain

  15. Development of an Air-Source Heat Pump Integrated with a Water Heating / Dehumidification Module

    SciTech Connect (OSTI)

    Rice, C Keith [ORNL] [ORNL; Uselton, Robert B. [Lennox Industries, Inc] [Lennox Industries, Inc; Shen, Bo [ORNL] [ORNL; Baxter, Van D [ORNL] [ORNL; Shrestha, Som S [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    A residential-sized dual air-source integrated heat pump (AS-IHP) concept is under development in partnership between ORNL and a manufacturer. The concept design consists of a two-stage air-source heat pump (ASHP) coupled on the air distribution side with a separate novel water heating/dehumidification (WH/DH) module. The motivation for this unusual equipment combination is the forecast trend for home sensible loads to be reduced more than latent loads. Integration of water heating with a space dehumidification cycle addresses humidity control while performing double-duty. This approach can be applied to retrofit/upgrade applications as well as new construction. A WH/DH module capable of ~1.47 L/h water removal and ~2 kW water heating capacity was assembled by the manufacturer. A heat pump system model was used to guide the controls design; lab testing was conducted and used to calibrate the models. Performance maps were generated and used in a TRNSYS sub-hourly simulation to predict annual performance in a well-insulated house. Annual HVAC/WH energy savings of ~35% are predicted in cold and hot-humid U.S. climates compared to a minimum efficiency baseline.

  16. Cycle-to-cycle control of reconfigurable die sheet metal forming

    E-Print Network [OSTI]

    Vaughan, Chester Dewey

    2004-01-01T23:59:59.000Z

    This research addresses cycle to cycle control as applied to a sheet metal stretch forming process. More specifically, it attempts to validate the use of cycle to cycle (CtC) control for a multiple input-multiple output ...

  17. Quantum Heat Engines, the Second Law and Maxwell's Daemon

    E-Print Network [OSTI]

    Tien D. Kieu

    2005-08-22T23:59:59.000Z

    We introduce a class of quantum heat engines which consists of two-energy-eigenstate systems, the simplest of quantum mechanical systems, undergoing quantum adiabatic processes and energy exchanges with heat baths, respectively, at different stages of a cycle. Armed with this class of heat engines and some interpretation of heat transferred and work performed at the quantum level, we are able to clarify some important aspects of the second law of thermodynamics. In particular, it is not sufficient to have the heat source hotter than the sink, but there must be a minimum temperature difference between the hotter source and the cooler sink before any work can be extracted through the engines. The size of this minimum temperature difference is dictated by that of the energy gaps of the quantum engines involved. Our new quantum heat engines also offer a practical way, as an alternative to Szilard's engine, to physically realise Maxwell's daemon. Inspired and motivated by the Rabi oscillations, we further introduce some modifications to the quantum heat engines with single-mode cavities in order to, while respecting the second law, extract more work from the heat baths than is otherwise possible in thermal equilibria. Some of the results above are also generalisable to quantum heat engines of an infinite number of energy levels including 1-D simple harmonic oscillators and 1-D infinite square wells.

  18. Water-heating dehumidifier

    DOE Patents [OSTI]

    Tomlinson, John J. (Knoxville, TN)

    2006-04-18T23:59:59.000Z

    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.

  19. The need for a characteristics-based approach to radioactive waste classification as informed by advanced nuclear fuel cycles using the fuel-cycle integration and tradeoffs (FIT) model

    SciTech Connect (OSTI)

    Djokic, D. [Department of Nuclear Engineering, University of California, Berkeley, 3115B Etcheverry Hall, Berkeley, CA 94720-1730 (United States); Piet, S.; Pincock, L.; Soelberg, N. [Idaho National Laboratory - INL, 2525 North Fremont Avenue, Idaho Falls, ID 83415 (United States)

    2013-07-01T23:59:59.000Z

    This study explores the impact of wastes generated from potential future fuel cycles and the issues presented by classifying these under current classification criteria, and discusses the possibility of a comprehensive and consistent characteristics-based classification framework based on new waste streams created from advanced fuel cycles. A static mass flow model, Fuel-Cycle Integration and Tradeoffs (FIT), was used to calculate the composition of waste streams resulting from different nuclear fuel cycle choices. Because heat generation is generally the most important factor limiting geological repository areal loading, this analysis focuses on the impact of waste form heat load on waste classification practices, although classifying by metrics of radiotoxicity, mass, and volume is also possible. Waste streams generated in different fuel cycles and their possible classification based on the current U.S. framework and international standards are discussed. It is shown that the effects of separating waste streams are neglected under a source-based radioactive waste classification system. (authors)

  20. Energy Innovation Hub Report Shows Philadelphia-area Building...

    Office of Environmental Management (EM)

    Innovation Hub Report Shows Philadelphia-area Building Retrofits Could Support 23,500 Jobs Energy Innovation Hub Report Shows Philadelphia-area Building Retrofits Could Support...

  1. Life Cycle Inventory of a CMOS Chip

    E-Print Network [OSTI]

    Boyd, Sarah; Dornfeld, David; Krishnan, Nikhil

    2006-01-01T23:59:59.000Z

    Reichl, H. “Life cycle inventory analysis and identificationAllen, D.T. ; “Life cycle inventory development for waferLife Cycle Inventory of a CMOS Chip Sarah Boyd and David

  2. Sustainability Features of Nuclear Fuel Cycle Options

    E-Print Network [OSTI]

    Passerini, Stefano

    The nuclear fuel cycle is the series of stages that nuclear fuel materials go through in a cradle to grave framework. The Once Through Cycle (OTC) is the current fuel cycle implemented in the United States; in which an ...

  3. Life-cycle Assessment of Semiconductors

    E-Print Network [OSTI]

    Boyd, Sarah B.

    2009-01-01T23:59:59.000Z

    yield. A hybrid life cycle assessment (LCA) model is used;more accurate life-cycle assessment (LCA) of electronicthe purposes of life-cycle assessment (LCA). While it may be

  4. Heat storage duration

    SciTech Connect (OSTI)

    Balcomb, J.D.

    1981-01-01T23:59:59.000Z

    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.

  5. Systems Analyses of Advanced Brayton Cycles For High Efficiency Zero Emission Plants

    SciTech Connect (OSTI)

    A. D. Rao; J. Francuz; A. Verma; G. S. Samuelsen

    2006-10-30T23:59:59.000Z

    The ultimate goal of this program is to identify the power block cycle conditions and/or configurations which could increase the overall thermal efficiency of the Baseline IGCC by about 8% on a relative basis (i.e., 8% on a heat rate basis). This document presents the cycle conditions and/or the configurations for evaluation in an initial screening analysis. These cycle conditions and/or configurations for investigation in the screening analysis are identified by literature searches and brain storming sessions. The screening analysis in turn narrows down the number of promising cases for detailed analysis.

  6. HEATS: Thermal Energy Storage

    SciTech Connect (OSTI)

    None

    2012-01-01T23:59:59.000Z

    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.

  7. 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)

    2007-09-18T23:59:59.000Z

    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.

  8. 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)

    2011-06-28T23:59:59.000Z

    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.

  9. 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 ......

  10. Passive solar space heating

    SciTech Connect (OSTI)

    Balcomb, J.D.

    1980-01-01T23:59:59.000Z

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

  11. Heat rejection system

    DOE Patents [OSTI]

    Smith, Gregory C. (Richland, WA); Tokarz, Richard D. (Richland, WA); Parry, Jr., Harvey L. (Richland, WA); Braun, Daniel J. (Richland, WA)

    1980-01-01T23:59:59.000Z

    A cooling system for rejecting waste heat consists of a cooling tower incorporating a plurality of coolant tubes provided with cooling fins and each having a plurality of cooling channels therein, means for directing a heat exchange fluid from the power plant through less than the total number of cooling channels to cool the heat exchange fluid under normal ambient temperature conditions, means for directing water through the remaining cooling channels whenever the ambient temperature rises above the temperature at which dry cooling of the heat exchange fluid is sufficient and means for cooling the water.

  12. Optimization of Air Conditioning Cycling

    E-Print Network [OSTI]

    Seshadri, Swarooph

    2012-10-19T23:59:59.000Z

    on a 3-ton residential air conditioner are then presented to intuitively understand the effect of expansion valve and evaporator fan cycling in a real system. A real time optimization method is explored and the feasibility, recommendations for a...

  13. Fuel cycle code, "FUELMOVE III"

    E-Print Network [OSTI]

    Sovka, Jerry Alois

    1963-01-01T23:59:59.000Z

    Further modifications to the fuel cycle code FUELMOVE are described which were made in an attempt to obtain results for reflected reactors operated under batch, outin, and bidirectional fueling schemes. Numerical methods ...

  14. Cycling operation of fossil plants

    SciTech Connect (OSTI)

    Devendorf, D.; Kulczycky, T.G. (Niagara Mohawk Power Corp., Syracuse, NY (USA))

    1991-05-01T23:59:59.000Z

    A necessity for many utilities today is the cycling of their fossil units. Fossil plants with their higher fuel costs are being converted to cycling operation to accommodate daily load swings and to decrease the overall system fuel costs. For a large oil-fired unit, such as Oswego Steam Station Unit 5, millions of dollars can be saved annually in fuel costs if the unit operates in a two-shift mode. However, there are also penalties attributable to cycling operation which are associated with availability and thermal performance. The objectives of Niagara Mohawk Power Corporation were to minimize the losses in availability and performance, and the degradation in the life of the equipment by incorporating certain cycling modifications into the unit. The objective of this project was to evaluate the effectiveness of three of these cycling modifications: (1) the superheater and turbine bypass (Hot Restart System), (2) the use of variable pressure operation, and (3) the full-flow condensate polishing system. To meet this objective, Unit 5 was tested using the cycling modifications, and a dynamic mathematical model of this unit was developed using the Modular Modeling System (MMS) Code from EPRI. This model was used to evaluate various operating modes and to assist in the assessment of operating procedures. 15 refs., 41 figs., 22 tabs.

  15. New Systems Showing the Light-Time Effect

    E-Print Network [OSTI]

    P. Zasche

    2007-11-18T23:59:59.000Z

    Two Algol-type eclipsing binary systems (EW Lyr and IV Cas) have been investigated for period changes. Our study was primarily focused on the light-time effect with an alternative explanation by magnetic activity cycles. In the case of EW Lyr we have found a third body in the orbit with a period of about 78 years, an amplitude A=0.052 days and orbital eccentricity e=0.57. For IV Cas the long period is 58 years, amplitude A=0.034 days and zero eccentricity. With these results we are also able to calculate mass functions and minimal masses of these components.

  16. Plasma heating and hot ion sustaining in mirror based hybrids

    SciTech Connect (OSTI)

    Moiseenko, V. E.; Agren, O. [Institute of Plasma Physics, National Science Center 'Kharkiv Institute of Physics and Technology', Akademichna St. 1, 61108 Kharkiv (Ukraine); Uppsala University, Angstroem Laboratory, Division of Electricity, Box 534, SE-75121 Uppsala (Sweden)

    2012-06-19T23:59:59.000Z

    Possibilities of plasma heating and sloshing ion sustaining in mirror based hybrids are briefly reviewed. Sloshing ions, i.e. energetic ions with a velocity distribution concentrated to a certain pitch-angle, play an important role in plasma confinement and generation of fusion neutrons in mirror machines. Neutral beam injection (NBI) is first discussed as a method to generate sloshing ions. Numerical results of NBI modeling for a stellarator-mirror hybrid are analyzed. The sloshing ions could alternatively be sustained by RF heating. Fast wave heating schemes, i.e. magnetic beach, minority and second harmonic heating, are addressed and their similarities and differences are described. Characteristic features of wave propagation in mirror hybrid devices including both fundamental harmonic minority and second harmonic heating are examined. Minority heating is efficient for a wide range of minority concentration and plasma densities; it allows one to place the antenna aside from the hot ion location. A simple-design strap antenna suitable for this has good performance. However, this scenario is appropriate only for light minority ions. The second harmonic heating can be applied for the heavy ion component. Arrangements are similar for minority and second harmonic heating. The efficiency of second harmonic heating is influenced by a weaker wave damping than for minority heating. Numerical calculations show that in a hybrid reactor scaled mirror machine the deuterium sloshing ions could be heated within the minority heating scheme, while the tritium ions could be sustained by second harmonic heating.

  17. Calculation of Heating Values for the High Flux Isotope Reactor

    SciTech Connect (OSTI)

    Peterson, Joshua L [ORNL] [ORNL; Ilas, Germina [ORNL] [ORNL

    2012-01-01T23:59:59.000Z

    Calculating the amount of energy released by a fission reaction (fission Q value) and the heating rate distribution in a nuclear reactor is an important part of the safety analysis. However, these calculations can become very complex. One of the codes that can be used for this type of analyses is the Monte Carlo transport code MCNP5. Currently it is impossible to calculate the Q value and heating rate disposition for delayed beta and delayed gamma particles directly from MCNP5. The purpose of this paper is to outline a rigorous method for indirectly calculating the Q values and heating rates in the High Flux Isotope Reactor (HFIR), based on previous similar studies carried out for very high-temperature reactor configurations. This method has been applied in this study to calculate heating rates for the beginning of cycle (BOC) and end-of-cycle (EOC) states of HFIR. In addition, the BOC results obtained for HFIR are compared with corresponding results for the Advanced Test Reactor. The fission Q value for HFIR was calculated as 200.2 MeV for the BOC and 201.3 MeV for the EOC. It was also determined that 95.1% and 95.4% of the heat was deposited within the HFIR fuel plates for the BOC and EOC models, respectively. This methodology can also be used for heating rate calculations for HFIR experiments.

  18. Water recovery using waste heat from coal fired power plants.

    SciTech Connect (OSTI)

    Webb, Stephen W.; Morrow, Charles W.; Altman, Susan Jeanne; Dwyer, Brian P.

    2011-01-01T23:59:59.000Z

    The potential to treat non-traditional water sources using power plant waste heat in conjunction with membrane distillation is assessed. Researchers and power plant designers continue to search for ways to use that waste heat from Rankine cycle power plants to recover water thereby reducing water net water consumption. Unfortunately, waste heat from a power plant is of poor quality. Membrane distillation (MD) systems may be a technology that can use the low temperature waste heat (<100 F) to treat water. By their nature, they operate at low temperature and usually low pressure. This study investigates the use of MD to recover water from typical power plants. It looks at recovery from three heat producing locations (boiler blow down, steam diverted from bleed streams, and the cooling water system) within a power plant, providing process sketches, heat and material balances and equipment sizing for recovery schemes using MD for each of these locations. It also provides insight into life cycle cost tradeoffs between power production and incremental capital costs.

  19. Extension of the supercritical carbon dioxide brayton cycle to low reactor power operation: investigations using the coupled anl plant dynamics code-SAS4A/SASSYS-1 liquid metal reactor code system.

    SciTech Connect (OSTI)

    Moisseytsev, A.; Sienicki, J. J. (Nuclear Engineering Division)

    2012-05-10T23:59:59.000Z

    Significant progress has been made on the development of a control strategy for the supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle enabling removal of power from an autonomous load following Sodium-Cooled Fast Reactor (SFR) down to decay heat levels such that the S-CO{sub 2} cycle can be used to cool the reactor until decay heat can be removed by the normal shutdown heat removal system or a passive decay heat removal system such as Direct Reactor Auxiliary Cooling System (DRACS) loops with DRACS in-vessel heat exchangers. This capability of the new control strategy eliminates the need for use of a separate shutdown heat removal system which might also use supercritical CO{sub 2}. It has been found that this capability can be achieved by introducing a new control mechanism involving shaft speed control for the common shaft joining the turbine and two compressors following reduction of the load demand from the electrical grid to zero. Following disconnection of the generator from the electrical grid, heat is removed from the intermediate sodium circuit through the sodium-to-CO{sub 2} heat exchanger, the turbine solely drives the two compressors, and heat is rejected from the cycle through the CO{sub 2}-to-water cooler. To investigate the effectiveness of shaft speed control, calculations are carried out using the coupled Plant Dynamics Code-SAS4A/SASSYS-1 code for a linear load reduction transient for a 1000 MWt metallic-fueled SFR with autonomous load following. No deliberate motion of control rods or adjustment of sodium pump speeds is assumed to take place. It is assumed that the S-CO{sub 2} turbomachinery shaft speed linearly decreases from 100 to 20% nominal following reduction of grid load to zero. The reactor power is calculated to autonomously decrease down to 3% nominal providing a lengthy window in time for the switchover to the normal shutdown heat removal system or for a passive decay heat removal system to become effective. However, the calculations reveal that the compressor conditions are calculated to approach surge such that the need for a surge control system for each compressor is identified. Thus, it is demonstrated that the S-CO{sub 2} cycle can operate in the initial decay heat removal mode even with autonomous reactor control. Because external power is not needed to drive the compressors, the results show that the S-CO{sub 2} cycle can be used for initial decay heat removal for a lengthy interval in time in the absence of any off-site electrical power. The turbine provides sufficient power to drive the compressors. Combined with autonomous reactor control, this represents a significant safety advantage of the S-CO{sub 2} cycle by maintaining removal of the reactor power until the core decay heat falls to levels well below those for which the passive decay heat removal system is designed. The new control strategy is an alternative to a split-shaft layout involving separate power and compressor turbines which had previously been identified as a promising approach enabling heat removal from a SFR at low power levels. The current results indicate that the split-shaft configuration does not provide any significant benefits for the S-CO{sub 2} cycle over the current single-shaft layout with shaft speed control. It has been demonstrated that when connected to the grid the single-shaft cycle can effectively follow the load over the entire range. No compressor speed variation is needed while power is delivered to the grid. When the system is disconnected from the grid, the shaft speed can be changed as effectively as it would be with the split-shaft arrangement. In the split-shaft configuration, zero generator power means disconnection of the power turbine, such that the resulting system will be almost identical to the single-shaft arrangement. Without this advantage of the split-shaft configuration, the economic benefits of the single-shaft arrangement, provided by just one turbine and lower losses at the design point, are more important to the overall cycle performance. Therefore, the single-shaft

  20. IMPLEMENTING GROUND SOURCE HEAT PUMP AND GROUND LOOP HEAT EXCHANGER

    E-Print Network [OSTI]

    IMPLEMENTING GROUND SOURCE HEAT PUMP AND GROUND LOOP HEAT EXCHANGER MODELS IN THE ENERGYPLUS #12;ii IMPLEMENTING GROUND SOURCE HEAT PUMP AND GROUND LOOP HEAT EXCHANGER MODELS IN THE ENERGYPLUS............................................................... 2 1.3. Overview of the Parameter Estimation Water-to-Water Heat Pump Model ........... 5 1