National Library of Energy BETA

Sample records for heating cycle shows

  1. recuperative heat transfer within the Brayton cycle

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

    recuperative heat transfer within the Brayton cycle - Sandia Energy Energy Search Icon ... SunShot Grand Challenge: Regional Test Centers recuperative heat transfer within the ...

  2. Test Plan for Heat Cycle Research Program, Phase I Supercritical...

    Office of Scientific and Technical Information (OSTI)

    Test Plan for Heat Cycle Research Program, Phase I Supercritical Cycle Tests Citation Details In-Document Search Title: Test Plan for Heat Cycle Research Program, Phase I ...

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

    DOE Patents [OSTI]

    Jardine, D.M.

    1983-03-22

    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.

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

    DOE Patents [OSTI]

    Jardine, Douglas M.

    1983-01-01

    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.

  5. Rankine cycle waste heat recovery system

    DOE Patents [OSTI]

    Ernst, Timothy C.; Nelson, Christopher R.

    2015-09-22

    A waste heat recovery (WHR) system connects a working fluid to fluid passages formed in an engine block and/or a cylinder head of an internal combustion engine, forming an engine heat exchanger. The fluid passages are formed near high temperature areas of the engine, subjecting the working fluid to sufficient heat energy to vaporize the working fluid while the working fluid advantageously cools the engine block and/or cylinder head, improving fuel efficiency. The location of the engine heat exchanger downstream from an EGR boiler and upstream from an exhaust heat exchanger provides an optimal position of the engine heat exchanger with respect to the thermodynamic cycle of the WHR system, giving priority to cooling of EGR gas. The configuration of valves in the WHR system provides the ability to select a plurality of parallel flow paths for optimal operation.

  6. Rankine cycle waste heat recovery system

    DOE Patents [OSTI]

    Ernst, Timothy C.; Nelson, Christopher R.

    2014-08-12

    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.

  7. Rankine cycle waste heat recovery system

    DOE Patents [OSTI]

    Ernst, Timothy C.; Nelson, Christopher R.

    2016-05-10

    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.

  8. Test Plan for Heat Cycle Research Program, Phase I Supercritical Cycle

    Office of Scientific and Technical Information (OSTI)

    Tests (Technical Report) | SciTech Connect Test Plan for Heat Cycle Research Program, Phase I Supercritical Cycle Tests Citation Details In-Document Search Title: Test Plan for Heat Cycle Research Program, Phase I Supercritical Cycle Tests The 60 kW Heat Cycle Research Facility (HCRF) provides a means of examining different concepts and components associated with the generation of electrical power from a geothermal resource using a binary power cycle. In this power cycle the heat or energy

  9. Sulfuric acid-sulfur heat storage cycle

    DOE Patents [OSTI]

    Norman, John H.

    1983-12-20

    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.

  10. Organic rankine cycle waste heat applications

    DOE Patents [OSTI]

    Brasz, Joost J.; Biederman, Bruce P.

    2007-02-13

    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.

  11. Study of Supercritical Carbon Dioxide Power Cycle for Low Grade Heat Conversion

    SciTech Connect (OSTI)

    Vidhi, Rachana; Goswami, Yogi D.; Chen, Huijuan; Stefanakos, Elias; Kuravi, Sarada; Sabau, Adrian S

    2011-01-01

    Research on supercritical carbon dioxide power cycles has been mainly focused on high temperature applications, such as Brayton cycle in a nuclear power plant. This paper conducts a comprehensive study on the feasibility of a CO2-based supercritical power cycle for low-grade heat conversion. Energy and exergy analyses of the cycle were conducted to discuss the obstacles as well as the potentials of using supercritical carbon dioxide as the working fluid for supercritical Rankine cycle, Carbon dioxide has desirable qualities such as low critical temperature, stability, little environmental impact and low cost. However, the low critical temperature might be a disadvantage for the condensation process. Comparison between a carbon dioxide-based supercritical Rankine cycle and an organic fluid-based supercritical Rankine cycle showed that the former needs higher pressure to achieve the same efficiency and a heat recovery system is necessary to desuperheat the turbine exhaust and pre-heat the pressure charged liquid.

  12. 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 Poster presented at the 16th Directions in Engine-Efficiency and Emissions Research ...

  13. Cascaded organic rankine cycles for waste heat utilization

    DOE Patents [OSTI]

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

    2011-05-17

    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.

  14. Taking on the Heat in Solar Cells: New Calculations Show Atomic...

    Office of Science (SC) Website

    Taking on the Heat in Solar Cells: New Calculations Show Atomic Vibrations Hurt Efficiency Theoretical modeling of energy loss in solar cells may lead to more efficient materials ...

  15. Stirling cycle heat pump for heating and/or cooling systems

    SciTech Connect (OSTI)

    Meijer, R.J.; Khalili, K.; Meijer, E.; Godett, T.M.

    1991-03-05

    This patent describes a duplex Stirling cycle machine acting as a heat pump. It comprises: a Stirling engine having pistons axially displaceable within parallel cylinders, the engine further having a swashplate rotatable about an axis of, rotation parallel to the cylinders and defining a plane inclined from the axis of rotation. The pistons connected to the swashplate via crossheads whereby axial displacement of the pistons is converted to rotation of the swashplate, and a Stirling cycle heat pump having a compression heat exchanger, an expansion heat exchanger and a regenerator with pistons equal in number to the engine pistons and axially displaceable within cylinders which are oriented co-axially with the engine cylinders. The crossheads further connected to the heat pump pistons whereby the heat pump pistons move simultaneously with the engine pistons over an equal stroke distance.

  16. A combined power and ejector refrigeration cycle for low temperature heat sources

    SciTech Connect (OSTI)

    Zheng, B.; Weng, Y.W.

    2010-05-15

    A combined power and ejector refrigeration cycle for low temperature heat sources is under investigation in this paper. The proposed cycle combines the organic Rankine cycle and the ejector refrigeration cycle. The ejector is driven by the exhausts from the turbine to produce power and refrigeration simultaneously. A simulation was carried out to analyze the cycle performance using R245fa as the working fluid. A thermal efficiency of 34.1%, an effective efficiency of 18.7% and an exergy efficiency of 56.8% can be obtained at a generating temperature of 395 K, a condensing temperature of 298 K and an evaporating temperature of 280 K. Simulation results show that the proposed cycle has a big potential to produce refrigeration and most exergy losses take place in the ejector. (author)

  17. Heat transfer head for a Stirling cycle machine

    SciTech Connect (OSTI)

    Emigh, S.G.; Noble, J.E.; Lehmann, G.A.

    1991-12-31

    This patent describes a two cylinder opposed Stirling cycle machine. It comprises a pair of coaxially aligned cylinders; a pair of displacers, the displacers being movably supported along a common axis within the respective cylinders for equal and opposite reciprocating motion with respect to one another between an expansion space at an inner end of each cylinder and a compression space at its outer end in a Stirling cycle mode of operation; a common heat acceptor located adjacent to the inner ends of the cylinders; and duct means in separate fluid communication with the respective expansion spaces of the two cylinders for confining the movement of working fluid in two fluid paths that respectively extend between the expansion space of one cylinder and the compression space of the other and through the common heat acceptor for effecting heat transfer between moving working fluid and the heat acceptor; the duct means comprising: two sets of channels formed within radial ribs circumferentially arranged in angularly spaced locations about the common axis of the cylinders in an alternating interleaved axial pattern communicating respectively with the expansion space of one cylinder or the other.

  18. Advanced Multi-Effect Distillation System for Desalination Using Waste Heat fromGas Brayton Cycles

    SciTech Connect (OSTI)

    Haihua Zhao; Per F. Peterson

    2012-10-01

    Generation IV high temperature reactor systems use closed gas Brayton Cycles to realize high thermal efficiency in the range of 40% to 60%. The waste heat is removed through coolers by water at substantially greater average temperature than in conventional Rankine steam cycles. This paper introduces an innovative Advanced Multi-Effect Distillation (AMED) design that can enable the production of substantial quantities of low-cost desalinated water using waste heat from closed gas Brayton cycles. A reference AMED design configuration, optimization models, and simplified economics analysis are presented. By using an AMED distillation system the waste heat from closed gas Brayton cycles can be fully utilized to desalinate brackish water and seawater without affecting the cycle thermal efficiency. Analysis shows that cogeneration of electricity and desalinated water can increase net revenues for several Brayton cycles while generating large quantities of potable water. The AMED combining with closed gas Brayton cycles could significantly improve the sustainability and economics of Generation IV high temperature reactors.

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

    SciTech Connect (OSTI)

    Ghafghazi, Saeed; Sowlati, T.; Sokhansanj, Shahabaddine; Melin, Staffan

    2011-03-01

    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

  20. Heat and mass transfer in open-cycle OTEC systems

    SciTech Connect (OSTI)

    Bharathan, D.; Kreith, F.; Owens, W.L.; Schlepp, D.

    1984-01-01

    The temperature difference between surface and deep water in the oceans represents a vast resource of thermal energy. A promising method of harnessing this resource is the open-cycle ocean thermal energy conversion (OC-OTEC) system, which utilizes steam evaporated from the surface water to power the turbine. In this paper the state of the art of heat and mass transfer related to evaporation and condensation of steam at low pressures in OC-OTEC is summarized and relevant research issues are discussed.

  1. Taking on the Heat in Solar Cells: New Calculations Show Atomic Vibrations

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

    Hurt Efficiency | U.S. DOE Office of Science (SC) Taking on the Heat in Solar Cells: New Calculations Show Atomic Vibrations Hurt Efficiency Basic Energy Sciences (BES) BES Home About Research Facilities Science Highlights Benefits of BES Funding Opportunities Basic Energy Sciences Advisory Committee (BESAC) Community Resources Contact Information Basic Energy Sciences U.S. Department of Energy SC-22/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3081 F:

  2. High-Temperature Components for Rankine-Cycle-Based Waste Heat Recovery

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

    Systems on Combustion Engines | Department of Energy High-Temperature Components for Rankine-Cycle-Based Waste Heat Recovery Systems on Combustion Engines High-Temperature Components for Rankine-Cycle-Based Waste Heat Recovery Systems on Combustion Engines This poster reports on recent developments, achievements, and capabilities within a virtual environment to predict the dynamic behavior of the Rankine cycle within real driving cycles. p-11_janssens.pdf (168.59 KB) More Documents &

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

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

    ... and reactor designs * Higher inlet air temp is required (+300C> eq) * Larger pellets are necessary * Multiple reactors are needed * Indirect heat transfer is not suitable ...

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

    SciTech Connect (OSTI)

    Arsalan Razani; Kwang J. Kim

    2001-12-01

    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

  5. Waste-heat boiler application for the Vresova combined cycle plant

    SciTech Connect (OSTI)

    Vicek, Z.

    1995-12-01

    This report describes a project proposal and implementation of two combined-cycle units of the Vresova Fuel Complex (PKV) with 2 x 200 MWe and heat supply. Participation of ENERGOPROJECT Praha a.s., in this project.

  6. Use of Multiple Reheat Helium Brayton Cycles to Eliminate the Intermediate Heat Transfer Loop for Advanced Loop Type SFRs

    SciTech Connect (OSTI)

    Haihua Zhao; Hongbin Zhang; Samuel E. Bays

    2009-05-01

    The sodium intermediate heat transfer loop is used in existing sodium cooled fast reactor (SFR) plant design as a necessary safety measure to separate the radioactive primary loop sodium from the water of the steam Rankine power cycle. However, the intermediate heat transfer loop significantly increases the SFR plant cost and decreases the plant reliability due to the relatively high possibility of sodium leakage. A previous study shows that helium Brayton cycles with multiple reheat and intercooling for SFRs with reactor outlet temperature in the range of 510°C to 650°C can achieve thermal efficiencies comparable to or higher than steam cycles or recently proposed supercritical CO2 cycles. Use of inert helium as the power conversion working fluid provides major advantages over steam or CO2 by removing the requirement for safety systems to prevent and mitigate the sodium-water or sodium-CO2 reactions. A helium Brayton cycle power conversion system therefore makes the elimination of the intermediate heat transfer loop possible. This paper presents a pre-conceptual design of multiple reheat helium Brayton cycle for an advanced loop type SFR. This design widely refers the new horizontal shaft distributed PBMR helium power conversion design features. For a loop type SFR with reactor outlet temperature 550°C, the design achieves 42.4% thermal efficiency with favorable power density comparing with high temperature gas cooled reactors.

  7. Exhaust Heat Driven Rankine Cycle for a Heavy Duty Diesel Engine |

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

    Department of Energy Driven Rankine Cycle for a Heavy Duty Diesel Engine Exhaust Heat Driven Rankine Cycle for a Heavy Duty Diesel Engine Presents progress to date and plans to develop a viable Rankine engine to harness useful brake power from wasted heat energy in heavy duty truck engine exhaust deer11_singh.pdf (2.07 MB) More Documents & Publications Increased Engine Efficiency via Advancements in Engine Combustion Systems Roadmapping Engine Technology for Post-2020 Heavy Duty Vehicles

  8. Performance of an Organic Rankine Cycle Waste Heat Recovery System for

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

    Light Duty Diesel Engines | Department of Energy 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 Diesel Engines Poster presented at the 16th Directions in Engine-Efficiency and Emissions Research (DEER) Conference in Detroit, MI, September 27-30, 2010. p-04_briggs.pdf (486.62 KB) More Documents & Publications Development of a Waste Heat Recovery System for Light Duty Diesel

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

    SciTech Connect (OSTI)

    CHUGH, Devesh; Gluesenkamp, Kyle R; Abdelaziz, Omar; Moghaddam, Saeed

    2014-01-01

    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

  10. Structural stability of 1100{degree}C heated Pd/k during absorption cycling in protium

    SciTech Connect (OSTI)

    Fisher, I.A.

    1993-03-12

    Pd/k is a hydride forming packing material which is used in the Thermal Cycling Absorption Process (TCAP). Palladium is supported on kieselguhr to create a packing material which will provide adequate void space to prevent excessive pressure drops and flow restrictions. The use of unsupported palladium would result in blockage of columns and clogging of filters due to the small particle size of unsupported palladium hydride powder. During pilot scale demonstrations, it was noted that the Pd/k packing material had degraded causing severe flow restrictions within the TCAP column. A solution to the problem involved the heating of Pd/k at 1,110{degree}C to strengthen the packing material, and render it more resistant to breakdown. The 1, 100{degree}C heated Pd/k has been shown to be more resistant to mechanical breakdown than the Pd/k prior to heat treatment. Two primary modes of Pd/k particle degradation have been identified: mechanical breakdown caused by particle fluidization and degradation caused by absorption/desorption cycling. Absorption/desorption cycling causes the palladium particles within the packing to expanded and contract upon formation and decomposition of the hydride, respectively. This expansion and contraction causes large localized stresses within the packing material, which if these stresses can not be accommodated within the packing will cause the material to crack and degrade. The purpose of this report is to document the results of the absorption/desorption cycling of 1,100{degree}C heated Pd/k and compare these results to the results obtained from the absorption/desorption cycling of Pd/k which had not been heated at 1, 100{degree}C.

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

    SciTech Connect (OSTI)

    2011-12-19

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

    SciTech Connect (OSTI)

    Dan Wendt; Greg Mines

    2011-10-01

    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

  13. Scale Resistant Heat Exchanger for Low Temperature Geothermal Binary Cycle Power Plant

    SciTech Connect (OSTI)

    Hays, Lance G.

    2014-11-18

    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

  14. A modified heat leak test facility employing a closed-cycle helium refrigerator

    SciTech Connect (OSTI)

    Boroski, W.N.

    1996-01-01

    A Heat Leak Test Facility (HLTF) has been in use at Fermilab for many years. The apparatus has successfully measured the thermal performance of a variety of cryostat components under simulated operating conditions. While an effective tool in the cryostat design process, the HLTF has several limitations. Temperatures are normally fixed at cryogen boiling points and run times are limited to cryogen inventory. Moreover, close personnel attention is required to maintain system inventories and sustain system equilibrium. To provide longer measurement periods without perturbation and to minimize personnel interaction, a new heat leak measurement facility (HLTF-2) has been designed that incorporates a closed-cycle helium refrigerator. The two-stage refrigerator provides cooling to the various temperature stations of the HLTF while eliminating the need for cryogens. Eliminating cryogen inventories has resulted in a reduction of the amount of direct personnel attention required.

  15. Exfoliation Propensity of Oxide Scale in Heat Exchangers Used for Supercritical CO2 Power Cycles

    SciTech Connect (OSTI)

    Sabau, Adrian S; Shingledecker, John P.; Kung, Steve; Wright, Ian G.; Nash, Jim

    2016-01-01

    Supercritical CO2 (sCO2) Brayton cycle systems offer the possibility of improved efficiency in future fossil energy power generation plants operating at temperatures of 650 C and above. As there are few data on the oxidation/corrosion behavior of structural alloys in sCO2 at these temperatures, modeling to predict the propensity for oxide exfoliation is not well developed, thus hindering materials selection for these novel cycles. The ultimate goal of this effort is to provide needed data on scale exfoliation behavior in sCO2 for confident alloy selection. To date, a model developed by ORNL and EPRI for the exfoliation of oxide scales formed on boiler tubes in high-temperature, high-pressure steam has proven useful for managing exfoliation in conventional steam plants. A major input provided by the model is the ability to predict the likelihood of scale failure and loss based on understanding of the evolution of the oxide morphologies and the conditions that result in susceptibility to exfoliation. This paper describes initial steps taken to extend the existing model for exfoliation of steam-side oxide scales to sCO2 conditions. The main differences between high-temperature, high-pressure steam and sCO2 that impact the model involve (i) significant geometrical differences in the heat exchangers, ranging from standard pressurized tubes seen typically in steam-producing boilers to designs for sCO2 that employ variously-curved thin walls to create shaped flow paths for extended heat transfer area and small channel cross-sections to promote thermal convection and support pressure loads; (ii) changed operating characteristics with sCO2 due to the differences in physical and thermal properties compared to steam; and (iii) possible modification of the scale morphologies, hence properties that influence exfoliation behavior, due to reaction with carbon species from sCO2. The numerical simulations conducted were based on an assumed sCO2 operating schedule and several

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

    SciTech Connect (OSTI)

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

    1986-04-01

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

  17. 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

    2013-02-01

    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.

  18. 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)

    2013-07-01

    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)

  19. Thermophysical properties of the Zr-0.01 Nb alloy at various heating rates and repeated cycles of heating-cooling

    SciTech Connect (OSTI)

    Petrova, I.I.; Peletsky, V.E.; Samsonov, B.N.

    1999-07-01

    The results of an experimental study of the heat capacity, enthalpy, electrical resistivity, and spectral emissivity (for the wavelength of 0.65 {micro}m) of the Zr-0.01 Nb alloy in the temperature range from 900 to 2,000 K are presented. The study was carried out using subsecond pulse heating of the samples by passing electrical current through them. Experiments were conducted at different heating rates (10{sup 3} to 10{sup 4} K {center{underscore}dot} s {sup minus}{sup 1}) and a series of experiments consisted of several cycles of pulse heating and subsequent cooling. The effect of these parameters on the temperature dependence of thermophysical properties in the region of the {alpha}-{beta} transition was studied. With an increase in the heating rate, the temperature of the {alpha}-{beta} transition, and the maximum in the heat capacity shifted to higher temperatures. There are significant differences in properties over the temperature range of the {alpha}-{beta} transition for the various heating cycles.

  20. 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

    2014-01-01

    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.

  1. Life cycle assessment of an energy-system with a superheated steam dryer integrated in a local district heat and power plant

    SciTech Connect (OSTI)

    Bjoerk, H.; Rasmuson, A.

    1999-07-01

    Life cycle assessment (LCA) is a method for analyzing and assessing the environmental impact of a material, product or service throughout the entire life cycle. In this study 100 GWh heat is to be demanded by a local heat district. A mixture of coal and wet biofuel is frequently used as fuel for steam generation (Case 1). A conversion of the mixed fuel to dried biofuel is proposed. In the district it is also estimated that it is possible for 4000 private houses to convert from oil to wood pellets. It is proposed that sustainable solution to the actual problem is to combine heat and power production together with an improvement in the quality of wood residues and manufacture of pellets. It is also proposed that a steam dryer is integrated to the system (Case 2). Most of the heat from the drying process is used by the municipal heating networks. In this study the environmental impact of the two cases is examined with LCA. Different valuation methods shows the Case 2 is an improvement over Case 1, but there is diversity in the magnitudes of environmental impact in the comparison of the cases. The differences depend particularly on how the emissions of CO{sub 2}, NO{sub x} and hydrocarbons are estimated. The impact of the organic compounds from the exhaust gas during the drying is estimated as low in all of the three used methods.

  2. Structural stability of 1100[degree]C heated Pd/k during absorption cycling in protium. [Palladium supported on kieselguhr

    SciTech Connect (OSTI)

    Fisher, I.A.

    1993-03-12

    Pd/k is a hydride forming packing material which is used in the Thermal Cycling Absorption Process (TCAP). Palladium is supported on kieselguhr to create a packing material which will provide adequate void space to prevent excessive pressure drops and flow restrictions. The use of unsupported palladium would result in blockage of columns and clogging of filters due to the small particle size of unsupported palladium hydride powder. During pilot scale demonstrations, it was noted that the Pd/k packing material had degraded causing severe flow restrictions within the TCAP column. A solution to the problem involved the heating of Pd/k at 1,110[degree]C to strengthen the packing material, and render it more resistant to breakdown. The 1, 100[degree]C heated Pd/k has been shown to be more resistant to mechanical breakdown than the Pd/k prior to heat treatment. Two primary modes of Pd/k particle degradation have been identified: mechanical breakdown caused by particle fluidization and degradation caused by absorption/desorption cycling. Absorption/desorption cycling causes the palladium particles within the packing to expanded and contract upon formation and decomposition of the hydride, respectively. This expansion and contraction causes large localized stresses within the packing material, which if these stresses can not be accommodated within the packing will cause the material to crack and degrade. The purpose of this report is to document the results of the absorption/desorption cycling of 1,100[degree]C heated Pd/k and compare these results to the results obtained from the absorption/desorption cycling of Pd/k which had not been heated at 1, 100[degree]C.

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

    SciTech Connect (OSTI)

    Vilim, R. B.; Nuclear Engineering Division

    2009-03-12

    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

  4. Zeolite Y adsorbents with high vapor uptake capacity and robust cycling stability for potential applications in advanced adsorption heat pumps

    SciTech Connect (OSTI)

    Li, XS; Narayanan, S; Michaelis, VK; Ong, TC; Keeler, EG; Kim, H; Mckay, IS; Griffin, RG; Wang, EN

    2015-01-01

    Modular and compact adsorption heat pumps (AHPs) promise an energy-efficient alternative to conventional vapor compression based heating, ventilation and air conditioning systems. A key element in the advancement of AHPs is the development of adsorbents with high uptake capacity, fast intracrystalline diffusivity and durable hydrothermal stability. Herein, the ion exchange of NaY zeolites with ingoing Mg2+ ions is systematically studied to maximize the ion exchange degree (IED) for improved sorption performance. It is found that beyond an ion exchange threshold of 64.1%, deeper ion exchange does not benefit water uptake capacity or characteristic adsorption energy, but does enhance the vapor diffusivity. In addition to using water as an adsorbate, the uptake properties of Mg, Na-Y zeolites were investigated using 20 wt.% MeOH aqueous solution as a novel anti-freeze adsorbate, revealing that the MeOH additive has an insignificant influence on the overall sorption performance. We also demonstrated that the lab-scale synthetic scalability is robust, and that the tailored zeolites scarcely suffer from hydrothermal stability even after successive 108-fold adsorption/desorption cycles. The samples were analyzed using N-2 sorption, Al-27/Si-29 MAS NMR spectroscopy, ICP-AES, dynamic vapor sorption, SEM, Fick's 2nd law and D-R equation regressions. Among these, close examination of sorption isotherms for H2O and N-2 adsorbates allows us to decouple and extract some insightful information underlying the complex water uptake phenomena. This work shows the promising performance of our modified zeolites that can be integrated into various AHP designs for buildings, electronics, and transportation applications. (C) 2014 Elsevier Inc. All rights reserved.

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

    DOE Patents [OSTI]

    Labinov, Solomon D.; Christian, Jeffrey E.

    2003-10-07

    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.

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

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

    More Documents & Publications Biodiesel Impact on Engine Lubricant Oil Dilution Statistical Analysis of Transient Cycle Test Results in a 40 CFR Part 1065 Engine Dynamometer Test ...

  7. A Highly Efficient Six-Stroke Internal Combustion Engine Cycle with Water Injection for In-Cylinder Exhaust Heat Recovery

    SciTech Connect (OSTI)

    Conklin, Jim; Szybist, James P

    2010-01-01

    A concept is presented here that adds two additional strokes to the four-stroke Otto or Diesel cycle that has the potential to increase fuel efficiency of the basic cycle. The engine cycle can be thought of as a 4 stroke Otto or Diesel cycle followed by a 2-stroke heat recovery steam cycle. Early exhaust valve closing during the exhaust stroke coupled with water injection are employed to add an additional power stroke at the end of the conventional four-stroke Otto or Diesel cycle. An ideal thermodynamics model of the exhaust gas compression, water injection at top center, and expansion was used to investigate this modification that effectively recovers waste heat from both the engine coolant and combustion exhaust gas. Thus, this concept recovers energy from two waste heat sources of current engine designs and converts heat normally discarded to useable power and work. This concept has the potential of a substantial increase in fuel efficiency over existing conventional internal combustion engines, and under appropriate injected water conditions, increase the fuel efficiency without incurring a decrease in power density. By changing the exhaust valve closing angle during the exhaust stroke, the ideal amount of exhaust can be recompressed for the amount of water injected, thereby minimizing the work input and maximizing the mean effective pressure of the steam expansion stroke (MEPsteam). The value of this exhaust valve closing for maximum MEPsteam depends on the limiting conditions of either one bar or the dew point temperature of the expansion gas/moisture mixture when the exhaust valve opens to discard the spent gas mixture in the sixth stroke. The range of MEPsteam calculated for the geometry of a conventional gasoline spark-ignited internal combustion engine and for plausible water injection parameters is from 0.75 to 2.5 bars. Typical combustion mean effective pressures (MEPcombustion) of naturally aspirated gasoline engines are up to 10 bar, thus this

  8. Base-Load and Peak Electricity from a Combined Nuclear Heat and Fossil Combined-Cycle Plant

    SciTech Connect (OSTI)

    Conklin, James C.; Forsberg, Charles W.

    2007-07-01

    A combined-cycle power plant is proposed that uses heat from a high-temperature reactor and fossil fuel to meet base-load and peak electrical demands. The high temperature gas turbine produces shaft power to turn an electric generator. The hot exhaust is then fed to a heat recovery steam generator (HRSG) that provides steam to a steam turbine for added electrical power production. A simplified computational model of the thermal power conversion system was developed in order to parametrically investigate two different steady-state operation conditions: base load nuclear heat only from an Advanced High Temperature Reactor (AHTR), and combined nuclear heat with fossil heat to increase the turbine inlet temperature. These two cases bracket the expected range of power levels, where any intermediate power level can result during electrical load following. The computed results indicate that combined nuclear-fossil systems have the potential to offer both low-cost base-load electricity and lower-cost peak power relative to the existing combination of base-load nuclear plants and separate fossil-fired peak-electricity production units. In addition, electric grid stability, reduced greenhouse gases, and operational flexibility can also result with using the conventional technology presented here for the thermal power conversion system coupled with the AHTR. (authors)

  9. Base-Load and Peak Electricity from a Combined Nuclear Heat and Fossil Combined-Cycle Plant

    SciTech Connect (OSTI)

    Conklin, Jim; Forsberg, Charles W

    2007-01-01

    A combined-cycle power plant is proposed that uses heat from a high-temperature reactor and fossil fuel to meet base-load and peak electrical demands. The high-temperature gas turbine produces shaft power to turn an electric generator. The hot exhaust is then fed to a heat recovery steam generator (HRSG) that provides steam to a steam turbine for added electrical power production. A simplified computational model of the thermal power conversion system was developed in order to parametrically investigate two different steady-state operation conditions: base load nuclear heat only from an Advanced High Temperature Reactor (AHTR), and combined nuclear heat with fossil heat to increase the turbine inlet temperature. These two cases bracket the expected range of power levels, where any intermediate power level can result during electrical load following. The computed results indicate that combined nuclear-fossil systems have the potential to offer both low-cost base-load electricity and lower-cost peak power relative to the existing combination of base-load nuclear plants and separate fossil-fired peak-electricity production units. In addition, electric grid stability, reduced greenhouse gases, and operational flexibility can also result with using the conventional technology presented here for the thermal power conversion system coupled with the AHTR.

  10. Parametric study of a silica gel-water adsorption refrigeration cycle -- The influence of thermal capacitance and heat exchanger UA-values on cooling capacity, power density, and COP

    SciTech Connect (OSTI)

    Boelman, E.C.; Saha, B.B.; Kashiwagi, Takao

    1997-12-31

    The influence of heat exchanger UA-values (adsorber/desorber, evaporator, and condenser) is investigated for an adsorption chiller, with consideration given to the thermal capacitance of the adsorber/desorber by means of a lumped-parameter cycle simulation model developed by the authors and co-workers for the single-stage silica gel-water adsorption chiller. The closed-cycle-type chiller, for use in air conditioning, is driven by low-grade waste heat (85 C [185 F]) and cooled by water at 31 C (88 F) and operates on relatively short cycle times (420 seconds adsorption/desorption; 30 second adsorber/desorber sensible cooling and heating). The results showed cycle performance to be considerably affected by the thermal capacitance and UA-value of the adsorber/desorber, which is attributed to the severe sensible cooling/heating requirements resulting from batched cycle operation. The model is also sensitive to the evaporator UA-value--but to a lesser extent. The condenser UA-value is the least sensitive parameter due to the working pair adsorption behavior in the temperature range defined for desorption and condensation.

  11. Waste heat recovery from adiabatic diesel engines by exhaust-driven Brayton cycles

    SciTech Connect (OSTI)

    Khalifa, H.E.

    1983-12-01

    This report presents an evaluation of Brayton Bottoming Systems (BBS) as waste heat recovery devices for future adiabatic diesel engines in heavy duty trucks. Parametric studies were performed to evaluate the influence of external and internal design parameters on BBS performance. Conceptual design and trade-off studies were undertaken to estimate the optimum configuration, size, and cost of major hardware components. The potential annual fuel savings of long-haul trucks equipped with BBS were estimated. The addition of a BBS to a turbocharged, nonaftercooled adiabatic engine would improve fuel economy by as much as 12%. In comparison with an aftercooled, turbocompound engine, the BBS-equipped turbocharged engine would offer a 4.4% fuel economy advantage. It is also shown that, if installed in tandem with an aftercooled turbocompound engine, the BBS could effect a 7.2% fuel economy improvement. The cost of a mass-produced 38 Bhp BBS is estimated at about $6460 or $170/Bhp. Technical and economic barriers that would hinder the commercial introduction of bottoming systems were identified.

  12. 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

    2013-09-01

    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

  13. 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.; Lee, J. I.

    2012-07-01

    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)

  14. Numerical Studies of Fluid Leakage from a Geologic DisposalReservoir for CO2 Show Self-Limiting Feedback between Fluid Flow and HeatTransfer

    SciTech Connect (OSTI)

    Pruess, Karsten

    2005-03-22

    Leakage of CO2 from a hypothetical geologic storage reservoir along an idealized fault zone has been simulated, including transitions between supercritical, liquid, and gaseous CO2. We find strong non-isothermal effects due to boiling and Joule-Thomson cooling of expanding CO2. Leakage fluxes are limited by limitations in conductive heat transfer to the fault zone. The interplay between multiphase flow and heat transfer effects produces non-monotonic leakage behavior.

  15. Employee Show

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

    Where Science Inspires Art Fermilab Employee Art Show 2015 Exhibition Dates -September 18, 2015 November 30, 2015 Reception - September 23, 2015 5 7pm Eligibility: Any current...

  16. Light Show

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

    9 Lightning - Nature's Light Show Lightning provides one of nature's most spectacular displays of energy. Though fascinating to observe, lightning can be dangerous and deadly. Protecting ARM instruments from lightning damage is vital. Putting equipment worth millions of dollars into open fields (Photo: NOAA) ARM Facilities Newsletter is published by Argonne National Laboratory, a multiprogram laboratory operated by The University of Chicago under contract W-31-109-Eng-38 with the U.S. Department

  17. Investigating potential efficiency improvement for light-duty transportation applications through simulation of an organic Rankine cycle for waste-heat recovery

    SciTech Connect (OSTI)

    Edwards, Kevin Dean; Wagner, Robert M

    2010-01-01

    Modern diesel engines used in light-duty transportation applications have peak brake thermal efficiencies in the range of 40-42% for high-load operation with substantially lower efficiencies at realistic road-load conditions. Thermodynamic energy and exergy analysis reveals that the largest losses from these engines are due to heat loss and combustion irreversibility. Substantial improvement in overall engine efficiency requires reducing or recovering these losses. Unfortunately, much of the heat transfer either occurs at relatively low temperatures resulting in large entropy generation (such as in the air-charge cooler), is transferred to low-exergy flow streams (such as the oil and engine coolant), or is radiated or convected directly to the environment. While there are significant opportunities for recovery from the exhaust and EGR cooler for heavy-duty applications, the potential benefits of such a strategy for light-duty applications are unknown due to transient operation, low-load operation at typical driving conditions, and the added mass of the system. We have developed an organic Rankine cycle model using GT-Suite to investigate the potential for efficiency improvement through waste-heat recovery from the exhaust and EGR cooler of a light-duty diesel engine. Results from steady-state and drive-cycle simulations are presented, and we discuss strategies to address operational difficulties associated with transient drive cycles and competition between waste-heat recovery systems, turbochargers, aftertreatment devices, and other systems for the limited thermal resources.

  18. Heat

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

    Release date: April 2015 Revised date: May 2016 Heat pumps Furnaces Indiv- idual space heaters District heat Boilers Pack- aged heating units Other All buildings 87,093 80,078 11,846 8,654 20,766 5,925 22,443 49,188 1,574 Building floorspace (square feet) 1,001 to 5,000 8,041 6,699 868 1,091 1,747 Q 400 3,809 Q 5,001 to 10,000 8,900 7,590 1,038 1,416 2,025 Q 734 4,622 Q 10,001 to 25,000 14,105 12,744 1,477 2,233 3,115 Q 2,008 8,246 Q 25,001 to 50,000 11,917 10,911 1,642 1,439 3,021 213 2,707

  19. " "," ",,," Steam Turbines Supplied by Either Conventional or Fluidized Bed Boilers",,,"Conventional Combusion Turbines with Heat Recovery",,,"Combined-Cycle Combusion Turbines",,,"Internal Combusion Engines with Heat Recovery",,," Steam Turbines Supplied by Heat Recovered from High-Temperature Processes",,,," "

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

    3 Relative Standard Errors for Table 8.3;" " Unit: Percents." " "," ",,," Steam Turbines Supplied by Either Conventional or Fluidized Bed Boilers",,,"Conventional Combusion Turbines with Heat Recovery",,,"Combined-Cycle Combusion Turbines",,,"Internal Combusion Engines with Heat Recovery",,," Steam Turbines Supplied by Heat Recovered from High-Temperature Processes",,,," " " "," "

  20. ,,,"with Any"," Steam Turbines Supplied by Either Conventional or Fluidized Bed Boilers",,,"Conventional Combusion Turbines with Heat Recovery",,,"Combined-Cycle Combusion Turbines",,,"Internal Combusion Engines with Heat Recovery",,," Steam Turbines Supplied by Heat Recovered from High-Temperature Processes",,,," "

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

    3 Relative Standard Errors for Table 8.3;" " Unit: Percents." ,,,"Establishments" ,,,"with Any"," Steam Turbines Supplied by Either Conventional or Fluidized Bed Boilers",,,"Conventional Combusion Turbines with Heat Recovery",,,"Combined-Cycle Combusion Turbines",,,"Internal Combusion Engines with Heat Recovery",,," Steam Turbines Supplied by Heat Recovered from High-Temperature Processes",,,," "

  1. 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.

    1981-11-02

    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.

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

    DOE Patents [OSTI]

    Berry, Gregory F.; Minkov, Vladimir; Petrick, Michael

    1988-01-01

    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.

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

    DOE Patents [OSTI]

    Berry, Gregory F.; Minkov, Vladimir; Petrick, Michael

    1988-01-05

    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.

  4. Thermodynamic analysis of adsorption refrigeration cycles

    SciTech Connect (OSTI)

    Saha, B.B.; Akisawa, Atsushi; Kashiwagi, Takao

    1997-12-31

    High- and mid-temperature waste heat can be recovered by using existing heat pump technologies. However, heat utilization near environmental temperatures still faces technical hurdles. Silica gel-water adsorption cycles have a distinct advantage over other systems in their ability to be driven by near-ambient temperature heat. Waste heat (above 60 C) can be exploited by using conventional silica gel-water adsorption chiller. The advanced silica gel-water adsorption chiller can operate effectively by utilizing low-grade waste heat ({approximately}50 C) as the driving source with a cooling source of 30 C. In this paper, the effect of operating temperatures on cycle performance is discussed from the thermodynamic viewpoint. The temperature effectiveness and the entropy generation number on cycle time are analyzed. For a comparatively short cycle time, adsorber/desorber heat exchanger temperature effectiveness reaches up to 92% after only 200 sec. The entropy generation number N{sub s} is defined by the ratio between irreversibility generated during a cycle and availability of the heat transfer fluid. The result showed that for the advanced adsorption cycle the entropy generation number N{sub s} is smaller for hot water temperature between 45 to 55 C with a cooling source of 30 C, while for the conventional cycle N{sub s} is smaller for hot water temperature between 65 to 75 C /with the same cooling source temperature.

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

    SciTech Connect (OSTI)

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

    2011-01-01

    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.

  6. Results of heat tests of the TGE-435 main boiler in the PGU-190/220 combined-cycle plant of the Tyumen' TETs-2 cogeneration plant

    SciTech Connect (OSTI)

    A.V. Kurochkin; A.L. Kovalenko; V.G. Kozlov; A.I. Krivobok

    2007-01-15

    Special features of operation of a boiler operating as a combined-cycle plant and having its own furnace and burner unit are descried. The flow of flue gases on the boiler is increased due to feeding of exhaust gases of the GTU into the furnace, which intensifies the convective heat exchange. In addition, it is not necessary to preheat air in the convective heating surfaces (the boiler has no air preheater). The convective heating surfaces of the boiler are used for heating the feed water, thus replacing the regeneration extractions of the steam turbine (HPP are absent in the circuit) and partially replacing the preheating of condensate (the LPP in the circuit of the unit are combined with preheaters of delivery water). Regeneration of the steam turbine is primarily used for the district cogeneration heating purposes. The furnace and burner unit of the exhaust-heat boiler (which is a new engineering solution for the given project) ensures utilization of not only the heat of the exhaust gases of the GTU but also of their excess volume, because the latter contains up to 15% oxygen that oxidizes the combustion process in the boiler. Thus, the gas temperature at the inlet to the boiler amounts to 580{sup o}C at an excess air factor a = 3.50; at the outlet these parameters are utilized to T{sub out} = 139{sup o}C and a{sub out} = 1.17. The proportions of the GTU/boiler loads that can actually be organized at the generating unit (and have been checked by testing) are presented and the proportions of loads recommended for the most efficient operation of the boiler are determined. The performance characteristics of the boiler are presented for various proportions of GTU/boiler loads. The operating conditions of the superheater and of the convective trailing heating surfaces are presented as well as the ecological parameters of the generating unit.

  7. 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

    2013-09-01

    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.

  8. Thermodynamic analysis of a possible CO{sub 2}-laser plant included in a heat engine cycle

    SciTech Connect (OSTI)

    Bisio, G.; Rubatto, G.

    1998-07-01

    In these last years, several plants have been realized in some industrialized countries to recover pressure exergy from various fluids. That has been done by means of suitable turbines in particular for blast-furnace top gas and natural gas. Various papers have examined the topic, considering pros and cons. High-power CO{sub 2}-lasers are being more and more widely used for welding, drilling and cutting in machine shops. In the near future different kinds of metal surface treatments will probably become routine practice with laser units. The industries benefiting most from high power lasers will be: the automotive industry, shipbuilding, the offshore industry, the aerospace industry, the nuclear and the chemical processing industries. Both degradation and cooling problems may be alleviated by allowing the gas to flow through the laser tube and by reducing its pressure outside this tube. Thus, a thermodynamic analysis on high-power CO{sub 2}-lasers with particular reference to a possible energy recovery is justified. In previous papers the critical examination of the concept of efficiency has led one of the present authors to the definition of an operational domain in which the process can be achieved. This domain is confined by regions of no entropy production (upper limit) and no useful effects (lower limit). On the basis of these concepts and of what has been done for pressure exergy recovery from other fluids, exergy investigations and an analysis of losses are performed for a cyclic process including a high performance CO2 laser. Thermodynamic analysis of flow processes in a CO{sub 2}-laser plant shows that the inclusion of a turbine in this plant allows us to recover the most part of the exergy necessary for the compressor; in addition, the water consumption for the refrigeration in the heat exchanger is reduced.

  9. Coupled modeling of a directly heated tubular solar receiver for supercritical carbon dioxide Brayton cycle: Optical and thermal-fluid evaluation

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

    Ortega, Jesus; Khivsara, Sagar; Christian, Joshua; Ho, Clifford; Yellowhair, Julius; Dutta, Pradip

    2016-05-30

    In single phase performance and appealing thermo-physical properties supercritical carbon dioxide (s-CO2) make a good heat transfer fluid candidate for concentrating solar power (CSP) technologies. The development of a solar receiver capable of delivering s-CO2 at outlet temperatures ~973 K is required in order to merge CSP and s-CO2 Brayton cycle technologies. A coupled optical and thermal-fluid modeling effort for a tubular receiver is undertaken to evaluate the direct tubular s-CO2 receiver’s thermal performance when exposed to a concentrated solar power input of ~0.3–0.5 MW. Ray tracing, using SolTrace, is performed to determine the heat flux profiles on the receivermore » and computational fluid dynamics (CFD) determines the thermal performance of the receiver under the specified heating conditions. Moreover, an in-house MATLAB code is developed to couple SolTrace and ANSYS Fluent. CFD modeling is performed using ANSYS Fluent to predict the thermal performance of the receiver by evaluating radiation and convection heat loss mechanisms. Understanding the effects of variation in heliostat aiming strategy and flow configurations on the thermal performance of the receiver was achieved through parametric analyses. Finally, a receiver thermal efficiency ~85% was predicted and the surface temperatures were observed to be within the allowable limit for the materials under consideration.« less

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

    SciTech Connect (OSTI)

    Piyush Sabharwall; Mike Patterson; Vivek Utgikar; Fred Gunnerson

    2008-09-01

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

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

    SciTech Connect (OSTI)

    Neises, T.; Turchi, C.

    2013-09-01

    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.

  12. "Integrated Gasification Combined Cycle"

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

    Turbine",,"X" " - Heat Recovery Steam Generator",,,"X" " - Gasifier",,"X" " - Balance of Plant",,,"X" "Conventional Natural Gas Combined Cycle" " - Conventional Combustion Turbine"...

  13. 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

    2012-04-26

    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.

  14. Coupled modeling of a directly heated tubular solar receiver for supercritical carbon dioxide Brayton cycle: Structural and creep-fatigue evaluation

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

    Ortega, Jesus; Khivsara, Sagar; Christian, Joshua; Ho, Clifford; Dutta, Pradip

    2016-06-06

    A supercritical carbon dioxide (sCO2) Brayton cycle is an emerging high energy-density cycle undergoing extensive research due to the appealing thermo-physical properties of sCO2 and single phase operation. Development of a solar receiver capable of delivering sCO2 at 20 MPa and 700 °C is required for implementation of the high efficiency (~50%) solar powered sCO2 Brayton cycle. In this work, extensive candidate materials are review along with tube size optimization using the ASME Boiler and Pressure Vessel Code. Moreover, temperature and pressure distribution obtained from the thermal-fluid modeling (presented in a complementary publication) are used to evaluate the thermal andmore » mechanical stresses along with detailed creep-fatigue analysis of the tubes. For resulting body stresses were used to approximate the lifetime performance of the receiver tubes. A cyclic loading analysis is performed by coupling the Strain-Life approach and the Larson-Miller creep model. The structural integrity of the receiver was examined and it was found that the stresses can be withstood by specific tubes, determined by a parametric geometric analysis. The creep-fatigue analysis display the damage accumulation due to cycling and the permanent deformation on the tubes showed that the tubes can operate for the full lifetime of the receiver.« less

  15. Heat pump system

    DOE Patents [OSTI]

    Swenson, Paul F.; Moore, Paul B.

    1979-01-01

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

  16. Heat pump system

    DOE Patents [OSTI]

    Swenson, Paul F.; Moore, Paul B.

    1982-01-01

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

  17. Minimize Boiler Short Cycling Losses, Energy Tips: STEAM, Steam...

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

    6 Minimize Boiler Short Cycling Losses Boiler "short cycling" occurs when an oversized boiler quickly satisfes process or space heating demands, and then shuts down until heat is ...

  18. Air-Source Heat Pump Basics | Department of Energy

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

    Air-Source Heat Pump Basics Air-Source Heat Pump Basics August 19, 2013 - 11:03am Addthis Air-source heat pumps transfer heat between the inside of a building and the outside air. How Air-Source Heat Pumps Work This diagram of a split-system heat pump heating cycle shows refrigerant circulating through a closed loop that passes through the wall of a house. Inside the house the refrigerant winds through indoor coils, with a fan blowing across them, and outside the house is another fan and another

  19. Variable pressure power cycle and control system

    DOE Patents [OSTI]

    Goldsberry, Fred L.

    1984-11-27

    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.

  20. Fast Reactor Fuel Cycle Cost Estimates for Advanced Fuel Cycle...

    Office of Scientific and Technical Information (OSTI)

    Title: Fast Reactor Fuel Cycle Cost Estimates for Advanced Fuel Cycle Studies Authors: Harrison, Thomas J 1 + Show Author Affiliations ORNL ORNL Publication Date: 2013-01-01 ...

  1. Fuel Cell Power Model Elucidates Life-Cycle Costs for Fuel Cell-Based Combined Heat, Hydrogen, and Power (CHHP) Production Systems (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2010-11-01

    This fact sheet describes NREL's accomplishments in accurately modeling costs for fuel cell-based combined heat, hydrogen, and power systems. Work was performed by NREL's Hydrogen Technologies and Systems Center.

  2. The turbulent cascade and proton heating in the solar wind during solar minimum

    SciTech Connect (OSTI)

    Coburn, Jesse T.; Smith, Charles W.; Vasquez, Bernard J.; Stawarz, Joshua E.; Forman, Miriam A.

    2013-06-13

    Solar wind measurements at 1 AU during the recent solar minimum and previous studies of solar maximum provide an opportunity to study the effects of the changing solar cycle on in situ heating. Our interest is to compare the levels of activity associated with turbulence and proton heating. Large-scale shears in the flow caused by transient activity are a source that drives turbulence that heats the solar wind, but as the solar cycle progresses the dynamics that drive the turbulence and heat the medium are likely to change. The application of third-moment theory to Advanced Composition Explorer (ACE) data gives the turbulent energy cascade rate which is not seen to vary with the solar cycle. Likewise, an empirical heating rate shows no significan changes in proton heating over the cycle.

  3. Superfluid thermodynamic cycle refrigerator

    DOE Patents [OSTI]

    Swift, Gregory W.; Kotsubo, Vincent Y.

    1992-01-01

    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.

  4. Superfluid thermodynamic cycle refrigerator

    DOE Patents [OSTI]

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

    1992-12-22

    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.

  5. Geothermal Energy Featured on NBC's Today Show

    Broader source: Energy.gov [DOE]

    In Iceland, there are five major geothermal power plants which produce about 26% (2006) of the country's electricity. In addition, geothermal heating meets the heating and hot water requirements for around 87% of the nation's buildings. As part of its "Ends of the Earth" series, NBC's Today Show presented a feature on the use of geothermal energy in Iceland.

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

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

    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 Cycle Cost ...

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

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

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

  8. Show Me PACE

    Broader source: Energy.gov [DOE]

    In July 2010 Missouri enacted the Property Assessed Clean Energy Act. In June 2015, Show Me PACE was established under this law as a Clean Energy Development Board. PACE financing allows property...

  9. New energy-conserving passive solar single-family homes. Cycle 5, Category 2 HUD solar heating and cooling demonstration program

    SciTech Connect (OSTI)

    Not Available

    1981-01-01

    The 91 new single-family, energy-conserving passive solar homes described represent award winning designs of the series of five demonstration cycles of the HUD program. Information is presented to help builders and lenders to understand passive solar design, to recognize passive solar buildings, and to provide specific design, construction, and marketing suggestions and details. The first section describes the concept of passive solar energy, explains the various functions which passive solar systems must perform, and discusses the various types of passive systems found in the Cycle 5 projects. The second section discusses each of the 91 solar homes. The third section details the issues of climate requirements and site design concerns, gives examples of building construction, and suggests how to market solar homes. The appendices address more technical aspects of the design and evaluation of passive solar homes.

  10. Experimental investigation of an advanced adsorption refrigeration cycle

    SciTech Connect (OSTI)

    Saha, B.B.; Kashiwagi, Takao

    1997-12-31

    Experimental measurements are made for a silica gel-water advanced absorption refrigeration chiller (1.2-kW [4,095-Btu/h] cooling capacity) to evaluate its performance under different temperature and adsorption/desorption cycle time conditions. This paper describes the operating principle of the chiller, outlines the experimental hardware, and discusses results obtained by varying the cooling and hot water inlet temperatures and adsorption/desorption cycle times, as well as their agreement with the simulated results given by a lumped parameter model. The chiller performance is analyzed in terms of cooling capacity and coefficient of performance (COP). Excellent qualitative agreement was obtained between the experimental data and simulated results. The results showed the advanced three-stage cycle to be particularly well suited for operation with low-grade-temperature waste heat as the driving source, since it worked with small regenerating temperature lifts (heat source-heat sink temperature) of 10 to 30 K.

  11. 2015 Washington Auto Show

    Broader source: Energy.gov [DOE]

    Secretary of Energy Ernest Moniz attended the 2015 Washington Auto Show in Washington, DC on January 22, 2015. He delivered brief remarks on the Energy Department's role in electric and fuel cell vehicle technology, announced more than $55 million in funding opportunities to support fuel-efficient vehicle technologies and visited several of the exhibits featuring recent additions to the vehicles market.

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

    SciTech Connect (OSTI)

    Smith, K.; Thornton, M.

    2009-04-01

    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.

  13. Absorption heat pump system

    DOE Patents [OSTI]

    Grossman, Gershon; Perez-Blanco, Horacio

    1984-01-01

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

  14. Efficiency combined cycle power plant

    SciTech Connect (OSTI)

    Pavel, J.; Meyers, G.A.; Baldwin, T.S.

    1990-06-12

    This patent describes a method of operating a combined cycle power plant. It comprises: flowing exhaust gas from a combustion turbine through a heat recovery steam generator (HRSG); flowing feed water through an economizer section of the HRSG at a flow rate and providing heated feed water; flowing a first portion of the heated feed water through an evaporator section of the HRSG and producing saturated steam at a production rate, the flow rate of the feed water through the economizer section being greater than required to sustain the production rate of steam in the evaporator section; flowing fuel for the turbine through a heat exchanger; and, flowing a second portion of the heated feed water provided by the economizer section through the heat exchanger then to an inlet of the economizer section, thereby heating the fuel flowing through the heat exchanger.

  15. TITAN'S TRANSPORT-DRIVEN METHANE CYCLE

    SciTech Connect (OSTI)

    Mitchell, Jonathan L.

    2012-09-10

    The mechanisms behind the occurrence of large cloud outbursts and precipitation on Titan have been disputed. A global- and annual-mean estimate of surface fluxes indicated only 1% of the insolation, or {approx}0.04 W m{sup -2}, is exchanged as sensible and/or latent fluxes. Since these fluxes are responsible for driving atmospheric convection, it has been argued that moist convection should be quite rare and precipitation even rarer, even if evaporation globally dominates the surface-atmosphere energy exchange. In contrast, climate simulations indicate substantial cloud formation and/or precipitation. We argue that the top-of-atmosphere (TOA) radiative imbalance is diagnostic of horizontal heat transport by Titan's atmosphere, and thus constrains the strength of the methane cycle. Simple calculations show the TOA radiative imbalance is {approx}0.5-1 W m{sup -2} in Titan's equatorial region, which implies 2-3 MW of latitudinal heat transport by the atmosphere. Our simulation of Titan's climate suggests this transport may occur primarily as latent heat, with net evaporation at the equator and net accumulation at higher latitudes. Thus, the methane cycle could be 10-20 times previous estimates. Opposing seasonal transport at solstices, compensation by sensible heat transport, and focusing of precipitation by large-scale dynamics could further enhance the local, instantaneous strength of Titan's methane cycle by a factor of several. A limited supply of surface liquids in regions of large surface radiative imbalance may throttle the methane cycle, and if so, we predict more frequent large storms over the lakes district during Titan's northern summer.

  16. 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.

    1980-07-01

    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)

  17. Data mining of space heating system performance in affordable housing

    SciTech Connect (OSTI)

    Ren, Xiaoxin; Yan, Da; Hong, Tianzhen

    2015-02-16

    The space heating in residential buildings accounts for a considerable amount of the primary energy use. Therefore, understanding the operation and performance of space heating systems becomes crucial in improving occupant comfort while reducing energy use. This study investigated the behavior of occupants adjusting their thermostat settings and heating system operations in a 62-unit affordable housing complex in Revere, Massachusetts, USA. The data mining methods, including clustering approach and decision trees, were used to ascertain occupant behavior patterns. Data tabulating ON/OFF space heating states was assessed, to provide a better understanding of the intermittent operation of space heating systems in terms of system cycling frequency and the duration of each operation. The decision tree was used to verify the link between room temperature settings, house and heating system characteristics and the heating energy use. The results suggest that the majority of apartments show fairly constant room temperature profiles with limited variations during a day or between weekday and weekend. Data clustering results revealed six typical patterns of room temperature profiles during the heating season. Space heating systems cycled more frequently than anticipated due to a tight range of room thermostat settings and potentially oversized heating capacities. In conclusion, from this study affirm data mining techniques are an effective method to analyze large datasets and extract hidden patterns to inform design and improve operations.

  18. Data mining of space heating system performance in affordable housing

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

    Ren, Xiaoxin; Yan, Da; Hong, Tianzhen

    2015-02-16

    The space heating in residential buildings accounts for a considerable amount of the primary energy use. Therefore, understanding the operation and performance of space heating systems becomes crucial in improving occupant comfort while reducing energy use. This study investigated the behavior of occupants adjusting their thermostat settings and heating system operations in a 62-unit affordable housing complex in Revere, Massachusetts, USA. The data mining methods, including clustering approach and decision trees, were used to ascertain occupant behavior patterns. Data tabulating ON/OFF space heating states was assessed, to provide a better understanding of the intermittent operation of space heating systems inmore » terms of system cycling frequency and the duration of each operation. The decision tree was used to verify the link between room temperature settings, house and heating system characteristics and the heating energy use. The results suggest that the majority of apartments show fairly constant room temperature profiles with limited variations during a day or between weekday and weekend. Data clustering results revealed six typical patterns of room temperature profiles during the heating season. Space heating systems cycled more frequently than anticipated due to a tight range of room thermostat settings and potentially oversized heating capacities. In conclusion, from this study affirm data mining techniques are an effective method to analyze large datasets and extract hidden patterns to inform design and improve operations.« less

  19. Supercritical carbon dioxide cycle control analysis.

    SciTech Connect (OSTI)

    Moisseytsev, A.; Sienicki, J. J.

    2011-04-11

    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

  20. Heat pipe array heat exchanger

    DOE Patents [OSTI]

    Reimann, Robert C.

    1987-08-25

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

  1. Gas-fueled absorption heat pump

    SciTech Connect (OSTI)

    Florette, M.; Peuportier, B.

    1982-01-01

    To determine the feasibility of using an absorption heat pump for residential space heating, French investigators are studying both theoretically and experimentally, the performance of the absorption cycle in terms of its efficiency and suitability to space-heating conditions. A 10-kW pilot unit is supplying data on design criteria, heat-exchange fluid selection, and heat and mass balances.

  2. Geothermal Heat Pumps - Heating Mode | Department of Energy

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

    Heating Mode Geothermal Heat Pumps - Heating Mode In winter, fluid passing through this vertical, closed loop system is warmed by the heat of the earth; this heat is then transferred to the building. Heating Mode Animated Slide (PowerPoint 493 KB) Note: To view this animation in PowerPoint use 'Slide Show' mode. Simple illustration showing the transfer of heat from the ground to a building space to provide space heating. Simple illustration showing the transfer of heat from the ground to a

  3. 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

    2011-11-01

    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

  4. UGE Scheduler Cycle Time

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

    UGE Scheduler Cycle Time UGE Scheduler Cycle Time Genepool Cycle Time Genepool Daily Genepool Weekly Phoebe Cycle Time Phoebe Daily Phoebe Weekly What is the Scheduler Cycle? The...

  5. Open cycle thermoacoustics

    SciTech Connect (OSTI)

    Reid, Robert Stowers

    2000-01-01

    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.

  6. Stirling cycle rotary engine

    SciTech Connect (OSTI)

    Chandler, J.A.

    1988-06-28

    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.

  7. ARM - Atmospheric Heat Budget

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

    The Atmospheric Heat Budget shows where the atmospheric heat energy comes from and where it goes. Practically all this energy ultimately comes from the sun in the form of the ...

  8. A general simulation model for Stirling cycles

    SciTech Connect (OSTI)

    Schulz, S.; Schwendig, F.

    1996-01-01

    A mathematical model for the calculation of the Stirling cycle and of similar processes is presented. The model comprises a method to reproduce schematically any kind of process configuration, including free piston engines. The differential balance equations describing the process are solved by a stable integration algorithm. Heat transfer and pressure loss are calculated by using new correlations, which consider the special conditions of the periodic compression/expansion respectively of the oscillating flow. A comparison between experimental data achieved by means of a test apparatus and calculated data shows a good agreement.

  9. Advanced regenerative absorption refrigeration cycles

    DOE Patents [OSTI]

    Dao, Kim

    1990-01-01

    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).

  10. Modeling Energy Recovery Using Thermoelectric Conversion Integrated with an Organic Rankine Bottoming Cycle

    SciTech Connect (OSTI)

    Miller, Erik W.; Hendricks, Terry J.; Peterson, Richard B.

    2009-07-01

    Hot engine exhaust represents a resource that is often rejected to the environment without further utilization. This resource is most prevalent in the transportation sector, but stationary engine-generator systems also typically do not utilize this resource. Engine exhaust is a source of high grade thermal energy that can potentially be utilized by various approaches to produce electricity or to drive heating and cooling systems. This paper describes a model system that employs thermoelectric conversion as a topping cycle integrated with an organic Rankine bottoming cycle for waste heat utilization. This approach is being developed to fully utilize the thermal energy contained in hot exhaust streams. The model is composed of a high temperature heat exchanger which extracts thermal energy for driving the thermoelectric conversion elements. However, substantial sensible heat remains in the exhaust stream after emerging from the heat exchanger. The model incorporates a closely integrated bottoming cycle to utilize this remaining thermal energy in the exhaust stream. The model has many interacting parameters that define combined system quantities such as overall output power, efficiency, and total energy utilization factors. In addition, the model identifies a maximum power operating point for the system. That is, the model can identify the optimal amount of heat to remove from the exhaust flow to run through the thermoelectric elements. Removing too much or too little heat from the exhaust stream in this stage will reduce overall cycle performance. The model has been developed such that heat exchanger UAh values, thermal resistances, ZT values, and multiple thermoelectric elements can be investigated in the context of system operation. The model also has the ability to simultaneously determine the effect of each cycle design parameter on the performance of the overall system, thus giving the ability to utilize as much waste heat as possible. Key analysis results are

  11. Absorption Heat Pumps | Department of Energy

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

    an ammonia-water absorption cycle to provide heating and cooling. As in a standard heat pump, the refrigerant (in this case, ammonia) is condensed in one coil to release its...

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

    SciTech Connect (OSTI)

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

    2008-07-17

    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.

  13. Performance evaluation of a combined-cycle cogeneration system

    SciTech Connect (OSTI)

    Huang, F.F.; Naumowicz, T.

    1999-07-01

    A methodology for performance evaluation of a combined-cycle cogeneration system has been presented. Results for such a system using an advanced gas-turbine as the prime mover show that it is a very versatile system. It can produce a large power-to-heat ratio together with a high second-law efficiency over a wide range of process steam pressures. This work also demonstrates once again that the most appropriate and useful performance parameters for decision-making in cogeneration system design are the second-law efficiency and the power-to-heat ratio.

  14. Use of oxide decompositions in advanced thermochemical hydrogen cycles for solar heat sources. Experimental results on the low-temperature reactions for the tricobalt tetraoxide-cobalt monoxide pair

    SciTech Connect (OSTI)

    Jones, W.M.; Bowman, M.G.

    1982-01-01

    The concept of utilizing oxide decompositions in advanced thermochemical hydrogen cycles for solar heat sources is introduced. It has particular interest in allowing direct transmission of energy to the process through an air window. A cycle for the Co/sub 3/O/sub 4/-CoO pair would be, schematically: (1) Co/sub 3/O/sub 4/ = 3CoO + 1/2 O/sub 2/; (2) I/sub 2/(s,1) + Mg(OH)/sub 2/ + 3CoO = MgI/sub 2/(aq) + Co/sub 3/O/sub 4/ + H/sub 2/O(1); (3) H/sub 2/O + MgI/sub 2/(aq) = MgO + 2HI; (4) 2 HI = H/sub 2/ + I/sub 2/; (5) MgO + H/sub 2/O = Mg(OH)/sub 2/. Reaction (2) should give a high concentration of MgI/sub 2/ that would be favorable for (3). The solutions would also contain iodine dissolved as polyiodide, partly offsetting this advantage. Preliminary results indicate that reaction (2) is slow at 150/sup 0/C. It is surmised that the mechanism of (2) consists of the iodine disproportionation reaction (6), followed by reaction (7). (6) I/sub 2/(s,1) + Mg(OH)/sub 2/ = 5/6 MgI/sub 2/(aq) + 1/6 Mg(IO/sub 3/)/sub 2/(aq) + H/sub 2/O(1); (7) 1/6 Mg(IO/sub 3/)/sub 2/(aq) + 3 CoO = 1/6 MgI/sub 2/(aq) + Co/sub 3/O/sub 4/. Other workers have found (6) to be relatively fast and with a good yield at 150/sup 0/C. We have found the independently studied reaction (7) to be sufficiently slow at 150/sup 0/C to account for the slowness of (2). The yield of (7) was found to be proportional to the square root of the time, which suggests that iodate must diffuse through an adherent, accumulating Co/sub 3/O/sub 4/ layer. Since (7) is much faster when Mg(IO/sub 3/)/sub 2/ is replaced by KIO/sub 3/, the Mg/sup 2 +/ ion may catalyze formation of an adherent Co/sub 3/O/sub 4/ spinel layer. The reactivity of CoO in the KIO/sub 3/ analog of (7) is greatly decreased by exposure to high temperature.

  15. Chemical heat pump

    DOE Patents [OSTI]

    Greiner, Leonard

    1980-01-01

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

  16. Improving the efficiency and availability analysis of a modified reheat regenerative Rankine cycle

    SciTech Connect (OSTI)

    Bassily, A.M.

    1999-07-01

    Reheating in a reheat regenerative steam power cycle increases efficiency by increasing the average temperature of heat reception, but also increases the irreversibility of feed water heaters by raising the temperature of the superheated steam used for the regenerative process. This paper introduces some modifications to the regular reheat regenerative steam power cycle that reduce the irreversibility of the regenerative process. An availability analysis of the modified cycle and the regular reheat regenerative cycle as well as a comparison study between both cycles is done. The results indicate that a gain in energy efficiency of up to 2.5% as the steam generator pressure varies is obtained when applying such modifications at the same conditions of pressure, temperature's number of reheating stages, and feed water heaters. The availability analysis showed that such increase in efficiency is due to the reduction of the irreversibility of the regeneration process of the modified cycle.

  17. Home Heating

    Broader source: Energy.gov [DOE]

    Your choice of heating technologies impacts your energy bill. Learn about the different options for heating your home.

  18. Development of advanced low-temperature heat transfer fluids for district heating and cooling, final report

    SciTech Connect (OSTI)

    Cho, Y.I.; Lorsch, H.G.

    1991-03-31

    The feasibility of adding phase change materials (PCMS) and surfactants to the heat transfer fluids in district cooling systems was investigated. It increases the thermal capacity of the heat transfer fluid and therefore decreases the volume that needs to be pumped. It also increases the heat transfer rate, resulting in smaller heat exchangers. The thermal behavior of two potential PCMS, hexadecane and tetradecane paraffin wax, was experimentally evaluated. The heat of fusion of these materials is approximately 60% of that of ice. They exhibit no supercooling and are stable under repeated thermal cycling. While test results for laboratory grade materials showed good agreement with data in the literature, both melting point and heat of fusion for commercial grade hexadecane were found to be considerably lower than literature values. PCM/water mixtures were tested in a laboratory-scale test loop to determine heat transfer and flow resistance properties. For 10% and 25% PCM/water slurries, the heat transfer enhancement was found to be approximately 18 and 30 percent above the value for water, respectively. Within the turbulent region, there is only a minor pumping penalty from the addition of up to 25% PCM to the water. Research is continuing on these fluids in order to determine their behavior in large-size loops and to arrive at optimum formulations.

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

    DOE Patents [OSTI]

    Hansen, Anthony D. A.; Jaklevic, Joseph M.

    1996-01-01

    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.

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

    DOE Patents [OSTI]

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

    1996-04-16

    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.

  1. Rankine cycle system and method

    DOE Patents [OSTI]

    Ernst, Timothy C.; Nelson, Christopher R.

    2014-09-09

    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.

  2. Guidelines for Supplier, Vendor Shows

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

    Guidelines for Supplier, Vendor Shows Guidelines for SupplierVendor or Professional Local Trade FairsShows As a premier national research and development laboratory, LANL seeks...

  3. Stirling engine heating system

    SciTech Connect (OSTI)

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

    1988-06-28

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

  4. CHP Industrial Bottoming and Topping Cycle with Energy Information...

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

    illustrates the CHP bottoming cycle. 3 In a bottoming cycle, which is also referred to as Waste Heat to Power (WHP), fuel is first used to provide thermal input to a furnace or...

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

    DOE Patents [OSTI]

    Szybist, James P; Conklin, James C

    2012-10-23

    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.

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

    Open Energy Info (EERE)

    Environmental and Life Cycle Cost Reduction Potential of Ground Source Heat Pump (GSHP) in Hot and Humid Climate Geothermal Project Jump to: navigation, search Last modified on...

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

    SciTech Connect (OSTI)

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

    1992-08-01

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

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

    SciTech Connect (OSTI)

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

    1992-01-01

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

  9. Absorption-heat-pump system

    DOE Patents [OSTI]

    Grossman, G.; Perez-Blanco, H.

    1983-06-16

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

  10. Electrochemical heat engine

    DOE Patents [OSTI]

    Elliott, Guy R. B.; Holley, Charles E.; Houseman, Barton L.; Sibbitt, Jr., Wilmer L.

    1978-01-01

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

  11. Backstage at the Daily Show

    Broader source: Energy.gov [DOE]

    Backstage footage from Secretary Chu's appearance on the Daily Show where he discuses the green room candy dish and possible lighting considerations.

  12. High efficiency Brayton cycles using LNG

    SciTech Connect (OSTI)

    Morrow, Charles W.

    2006-04-18

    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.

  13. GAX absorption cycle design process

    SciTech Connect (OSTI)

    Priedeman, D.K.; Christensen, R.N.

    1999-07-01

    This paper presents an absorption system design process that relies on computer simulations that are validated by experimental findings. An ammonia-water absorption heat pump cycle at 3 refrigeration tons (RT) and chillers at 3.3 RT and 5 RT (10.5 kW, 11.6 kW, and 17.6 kW) were initially modeled and then built and tested. The experimental results were used to calibrate both the cycle simulation and the component simulations, yielding computer design routines that could accurately predict component and cycle performance. Each system was a generator-absorber heat exchange (GAX) cycle, and all were sized for residential and light commercial use, where very little absorption equipment is currently used. The specific findings of the 5 RT (17.6 kW) chiller are presented. Modeling incorporated a heat loss from the gas-fired generator and pressure drops in both the evaporator and absorber. Simulation results and experimental findings agreed closely and validated the modeling method and simulation software.

  14. Methods and compositions for rapid thermal cycling

    DOE Patents [OSTI]

    Beer, Neil Reginald; Benett, William J.; Frank, James M.; Deotte, Joshua R.; Spadaccini, Christopher

    2015-10-27

    The rapid thermal cycling of a material is targeted. A microfluidic heat exchanger with an internal porous medium is coupled to tanks containing cold fluid and hot fluid. Fluid flows alternately from the cold tank and the hot tank into the porous medium, cooling and heating samples contained in the microfluidic heat exchanger's sample wells. A valve may be coupled to the tanks and a pump, and switching the position of the valve may switch the source and direction of fluid flowing through the porous medium. A controller may control the switching of valve positions based on the temperature of the samples and determined temperature thresholds. A sample tray for containing samples to be thermally cycled may be used in conjunction with the thermal cycling system. A surface or internal electrical heater may aid in heating the samples, or may replace the necessity for the hot tank.

  15. Methods and compositions for rapid thermal cycling

    DOE Patents [OSTI]

    Beer, Neil Reginald; Benett, William J; Frank, James M; Deotte, Joshue R; Spadaccini, Christopher

    2015-11-06

    The rapid thermal cycling of a material is targeted. A microfluidic heat exchanger with an internal porous medium is coupled to tanks containing cold fluid and hot fluid. Fluid flows alternately from the cold tank and the hot tank into the porous medium, cooling and heating samples contained in the microfluidic heat exchanger's sample wells. A valve may be coupled to the tanks and a pump, and switching the position of the valve may switch the source and direction of fluid flowing through the porous medium. A controller may control the switching of valve positions based on the temperature of the samples and determined temperature thresholds. A sample tray for containing samples to be thermally cycled may be used in conjunction with the thermal cycling system. A surface or internal electrical heater may aid in heating the samples, or may replace the necessity for the hot tank.

  16. Heat transfer research for ocean thermal energy conversion

    SciTech Connect (OSTI)

    Kreith, F.; Bharathan, D.

    1988-02-01

    In this lecture an overview of the heat and mass-transfer phenomena of importance in ocean thermal energy conversion (OTEC) is presented with particular emphasis on open-cycle OTEC systems. Also included is a short historical review of OTEC developments in the past century and a comparison of open and closed-cycle thermodynamics. Finally, results of system analyses, showing the effect of plant size on cost and the near-term potential of using OTEC for combined power production and desalination systems, are briefly discussed.

  17. Heat transfer research for ocean thermal energy conversion

    SciTech Connect (OSTI)

    Kreith, F.; Bharathan, D.

    1987-03-01

    In this lecture an overview of the heat- and mass-transfer phenomena of importance in ocean thermal energy conversion (OTEC) is presented with particular emphasis on open-cycle OTEC systems. Also included is a short historical review of OTEC developments in the past century and a comparison of open- and closed-cycle thermodynamics. Finally, results of system analyses, showing the effect of plant size on cost and the near-term potential of using OTEC for combined power production and desalination systems are briefly discussed.

  18. Energy recovery system using an organic rankine cycle

    DOE Patents [OSTI]

    Ernst, Timothy C

    2013-10-01

    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.

  19. Method for processing LNG for rankine cycle

    SciTech Connect (OSTI)

    Aoki, I.; Matsumoto, O.

    1983-06-14

    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.

  20. ShowMe3D

    Energy Science and Technology Software Center (OSTI)

    2012-01-05

    ShowMe3D is a data visualization graphical user interface specifically designed for use with hyperspectral image obtained from the Hyperspectral Confocal Microscope. The program allows the user to select and display any single image from a three dimensional hyperspectral image stack. By moving a slider control, the user can easily move between images of the stack. The user can zoom into any region of the image. The user can select any pixel or region from themore » displayed image and display the fluorescence spectrum associated with that pixel or region. The user can define up to 3 spectral filters to apply to the hyperspectral image and view the image as it would appear from a filter-based confocal microscope. The user can also obtain statistics such as intensity average and variance from selected regions.« less

  1. Analysis of Energy, Environmental and Life Cycle Cost Reduction Potential

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

    of Ground Source Heat Pump (GSHP) in Hot and Humid Climate | Department of Energy 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 Cycle Cost Reduction Potential of Ground Source Heat Pump (GSHP) in Hot and Humid Climate Project objectives: Gather and analyze independently the available technical, cost, financial incentive data on installed GSHP/HGSHP applications in

  2. Induced natural convection thermal cycling device

    DOE Patents [OSTI]

    Heung, Leung Kit

    2002-08-13

    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.

  3. Combined rankine and vapor compression cycles

    DOE Patents [OSTI]

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

    2005-04-19

    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.

  4. Heat exchanger

    DOE Patents [OSTI]

    Daman, Ernest L.; McCallister, Robert A.

    1979-01-01

    A heat exchanger is provided having first and second fluid chambers for passing primary and secondary fluids. The chambers are spaced apart and have heat pipes extending from inside one chamber to inside the other chamber. A third chamber is provided for passing a purge fluid, and the heat pipe portion between the first and second chambers lies within the third chamber.

  5. Pros and cons of power combined cycle in Venezuela

    SciTech Connect (OSTI)

    Alvarez, C.; Hernandez, S.

    1997-09-01

    In Venezuela combined cycle power has not been economically attractive to electric utility companies, mainly due to the very low price of natural gas. Savings in cost of natural gas due to a higher efficiency, characteristic of this type of cycle, does not compensate additional investments required to close the simple cycle (heat recovery steam generator (HRSG) and steam turbine island). Low gas prices have contributed to create a situation characterized by investors` reluctance to commit capital in gas pipe lines and associated equipment. The Government is taking measures to improve economics. Recently (January 1, 1997), the Ministry of Energy and Mines raised the price of natural gas, and established a formula to tie its price to the exchange rate variation (dollar/bolivar) in an intent to stimulate investments in this sector. This is considered a good beginning after a price freeze for about three years. Another measure that has been announced is the implementation of a corporate policy of outsourcing to build new gas facilities such as pipe lines and measuring and regulation stations. Under these new circumstances, it seems that combined cycle will play an important role in the power sector. In fact, some power generation projects are considering building new plants using this technology. An economical comparative study is presented between simple and combined cycles power plant. Screening curves are showed with a gas price forecast based on the government decree recently issued, as a function of plant capacity factor.

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

    SciTech Connect (OSTI)

    Edwin A. Harvego; Michael G. McKellar

    2011-05-01

    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

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

    SciTech Connect (OSTI)

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

    2014-01-01

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

  8. UGE Scheduler Cycle Time

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

    UGE Scheduler Cycle Time UGE Scheduler Cycle Time Genepool Cycle Time Genepool Scheduler Cycle Time Genepool Jobs Dispatched / Hour What is the Scheduler Cycle? The Univa Grid Engine Scheduler cycle performs a number of important tasks, including: Prioritizing Jobs Reserving Resources for jobs requesting more resources (slots / memory) Dispatching jobs or tasks to the compute nodes Evaluating job dependencies The "cycle time" is the length of time it takes the scheduler to complete all

  9. Nonlinear heat-release/acoustic model for thermoacoustic instability in lean premixed combustors

    SciTech Connect (OSTI)

    Peracchio, A.A.; Proscia, W.M.

    1999-07-01

    Lean premixed combustors, such as those used in industrial gas turbines to achieve low emissions, are often susceptible to thermoacoustic combustion instabilities, which manifest themselves as pressure and heat release oscillations in the combustor. These oscillations can result in increased noise and decreased durability due to vibration and flame motion. A physically based nonlinear parametric model has been developed that captures this instability. It describes the coupling of combustor acoustics with the rate of heat release. The model represents this coupling by accounting for the effect of acoustic pressure fluctuations on the varying fuel/air ratio being delivered to the flame, causing a fluctuating heat release due to both fuel air ratio variations and flame front oscillations. If the phasing of the fluctuating heat release and pressure are proper, an instability results that grows into a limit cycle. The nonlinear nature of the model predicts the onset of the instability and additionally captures the resulting limit cycle. Tests of a lean premixed nozzle at engine scale and engine operating conditions in the UTRC single nozzle rig, conducted under DARPA contract, exhibited instabilities. Parameters from the model were adjusted so that analytical results were consistent with relevant experimental data from this test. The parametric model captures the limit cycle behavior over a range of mean fuel air ratios, showing the instability amplitude (pressure and heat release) to increase and limit cycle frequency to decrease as mean fuel air ratio is reduced.

  10. Total Space Heating Water Heating Cook-

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

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

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. Modifications and Optimization of the Organic Rankine Cycle

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

    Modifications and Optimization of the Organic Rankine Cycle Improved Recovery of Waste Heat in Industrial Processes Introduction Waste heat from turbines and engines used in industrial ap- plications along with waste heat from industrial processes are exceptionally abundant sources of energy. If even a fraction of this waste heat could be economically converted to useful elec- tricity, it would have a tangible and very positive impact on the economic health, energy consumption, and carbon

  17. 2013 Planning Cycle

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

    Projects Expand Projects Skip navigation links Ancillary and Control Area Services (ACS) Practices Forum Attachment K 2015 Planning Cycle 2014 Planning Cycle 2013 Planning...

  18. 2014 Planning Cycle

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

    Projects Expand Projects Skip navigation links Ancillary and Control Area Services (ACS) Practices Forum Attachment K 2015 Planning Cycle 2014 Planning Cycle 2013 Planning...

  19. 2015 Planning Cycle

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

    Projects Expand Projects Skip navigation links Ancillary and Control Area Services (ACS) Practices Forum Attachment K 2015 Planning Cycle 2014 Planning Cycle 2013 Planning...

  20. Fuel cycle cost uncertainty from nuclear fuel cycle comparison

    SciTech Connect (OSTI)

    Li, J.; McNelis, D.; Yim, M.S.

    2013-07-01

    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.

  1. Future Heating | Open Energy Information

    Open Energy Info (EERE)

    London, England, United Kingdom Sector: Solar Product: Designs and installs solar passive water heating systems. Coordinates: 51.506325, -0.127144 Show Map Loading map......

  2. Transposed critical temperature Rankine thermodynamic cycle

    SciTech Connect (OSTI)

    Pope, W.L.; Doyle, P.A.

    1980-04-01

    The transposed critical temperature (TPCT) is shown to be an extremely important thermodynamic property in the selection of the working fluid and turbine states for optimized geothermal power plants operating on a closed organic (binary) Rankine cycle. When the optimum working fluid composition and process states are determined for given source and sink conditions (7 parameter optimization), turbine inlet states are found to be consistently adjacent to the low pressure side of the working fluids' TPCT line on pressure-enthalpy coordinates. Although the TPCT concepts herein may find numerous future applications in high temperature, advanced cycles for fossil or nuclear fired steam power plants and in supercritical organic Rankine heat recovery bottoming cycles for Diesel engines, this discussion is limited to moderate temperature (150 to 250/sup 0/C) closed simple organic Rankine cycle geothermal power plants. Conceptual design calculations pertinent to the first geothermal binary cycle Demonstration Plant are included.

  3. Triple-effect absorption chiller cycles

    SciTech Connect (OSTI)

    DeVault, R.C. ); Grossman, G. )

    1992-01-01

    Gas-fired absorption chillers are widely used for air-conditioning buildings. Even the highest efficiency double-effect absorption chillers used more primary energy for air-conditioning buildings than the better electric chillers. Two different triple-effect absorption chiller cycles are capable of substantial performance improvement over equivalent double-effect cycles. One cycle uses two condensers and two absorbers to achieve the triple effect.'' A second cycle, the Double-Condenser Coupled Triple-Effect, uses three condensers as well as a third condenser subcooler (which exchanges heat with the lowest temperature first-effect generator). These triple-effect absorption cycles have the potential to be as energy efficient (on a primary fuel basis) as the best electric chillers. 19 refs.

  4. Triple-effect absorption chiller cycles

    SciTech Connect (OSTI)

    DeVault, R.C.; Grossman, G.

    1992-06-01

    Gas-fired absorption chillers are widely used for air-conditioning buildings. Even the highest efficiency double-effect absorption chillers used more primary energy for air-conditioning buildings than the better electric chillers. Two different triple-effect absorption chiller cycles are capable of substantial performance improvement over equivalent double-effect cycles. One cycle uses two condensers and two absorbers to achieve the ``triple effect.`` A second cycle, the Double-Condenser Coupled Triple-Effect, uses three condensers as well as a third condenser subcooler (which exchanges heat with the lowest temperature first-effect generator). These triple-effect absorption cycles have the potential to be as energy efficient (on a primary fuel basis) as the best electric chillers. 19 refs.

  5. A Finite Element Model Of Self-Resonating Bimorph Microcantilever For Fast Temperature Cycling In A Pyroelectric Energy Harvester

    SciTech Connect (OSTI)

    Mostafa, Salwa; Lavrik, Nickolay V; Bannuru, Thirumalesh; Rajic, Slobodan; Islam, Syed K; Datskos, Panos G; Hunter, Scott Robert

    2011-01-01

    A self resonating bimorph cantilever structure for fast temperature cycling in a pyroelectric energy harvester has been modeled using a finite element method. The effect of constituting material properties and system parameters on the frequency and magnitude of temperature cycling and the efficiency of energy recycling using the proposed structure has been investigated. Results show that thermal contact conductance and heat source temperature play a key role in dominating the cycling frequency and efficiency of energy recycling. An optimal solution for the most efficient energy scavenging process has been sought by studying the performance trend with different variable parameters such as thermal contact conductance, heat source temperature, device aspect ratio and constituent materials of varying thermal conductivity and expansion coefficients.

  6. Field measurement of the interactions between heat pumps and attic duct systems in residential buildings

    SciTech Connect (OSTI)

    Modera, M.P.; Jump, D.A.

    1994-11-01

    Research efforts to improve residential heat-pump performance have tended to focus on laboratory and theoretical studies of the machine itself, with some limited field research having been focused on in-situ performance and installation issues. One issue that has received surprisingly little attention is the interaction between the heat pump and the duct system to which it is connected. This paper presents the results of a field study that addresses this interaction. Field performance measurements before and after sealing and insulating the duct systems were made on three heat pumps. From the pre-retrofit data it was found that reductions in heat-pump capacity due to low outdoor temperatures and/or coil frosting are accompanied by lower duct-system energy delivery efficiencies. The conduction loss reductions, and thus the delivery temperature improvements, due to adding duct insulation were found to vary widely depending on the length of the particular duct section, the thermal mass of that duct section, and the cycling characteristics of the heat-pump. In addition, it was found that the use of strip-heat back-up decreased after the retrofits, and that heat-pump cycling increased dramatically after the retrofits, which respectively increase and decrease savings due to the retrofits. Finally, normalized energy use for the three systems which were operated consistently pre- and post-retrofit showed an average reduction of 19% after retrofit, which corresponds to a chance in overall distribution-system efficiency of 24%.

  7. Organic rankine cycle fluid

    DOE Patents [OSTI]

    Brasz, Joost J.; Jonsson, Ulf J.

    2006-09-05

    A method of operating an organic rankine cycle system wherein a liquid refrigerant is circulated to an evaporator where heat is introduced to the refrigerant to convert it to vapor. The vapor is then passed through a turbine, with the resulting cooled vapor then passing through a condenser for condensing the vapor to a liquid. The refrigerant is one of CF.sub.3CF.sub.2C(O)CF(CF.sub.3).sub.2, (CF.sub.3).sub.2 CFC(O)CF(CF.sub.3).sub.2, CF.sub.3(CF.sub.2).sub.2C(O)CF(CF.sub.3).sub.2, CF.sub.3(CF.sub.2).sub.3C(O)CF(CG.sub.3).sub.2, CF.sub.3(CF.sub.2).sub.5C(O)CF.sub.3, CF.sub.3CF.sub.2C(O)CF.sub.2CF.sub.2CF.sub.3, CF.sub.3C(O)CF(CF.sub.3).sub.2.

  8. Heat collector

    DOE Patents [OSTI]

    Merrigan, M.A.

    1981-06-29

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

  9. Heat collector

    DOE Patents [OSTI]

    Merrigan, Michael A.

    1984-01-01

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

  10. Combined cycle power plant incorporating coal gasification

    DOE Patents [OSTI]

    Liljedahl, Gregory N.; Moffat, Bruce K.

    1981-01-01

    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.

  11. HEAT EXCHANGER

    DOE Patents [OSTI]

    Fox, T.H. III; Richey, T. Jr.; Winders, G.R.

    1962-10-23

    A heat exchanger is designed for use in the transfer of heat between a radioactive fiuid and a non-radioactive fiuid. The exchanger employs a removable section containing the non-hazardous fluid extending into the section designed to contain the radioactive fluid. The removable section is provided with a construction to cancel out thermal stresses. The stationary section is pressurized to prevent leakage of the radioactive fiuid and to maintain a safe, desirable level for this fiuid. (AEC)

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

    SciTech Connect (OSTI)

    Kanzaka, M. ); Iwabuchi, M. )

    1991-01-01

    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.

  13. Corrosive resistant heat exchanger

    DOE Patents [OSTI]

    Richlen, Scott L.

    1989-01-01

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

  14. Performance analysis of an OTEC plant and a desalination plant using an integrated hybrid cycle

    SciTech Connect (OSTI)

    Uehara, Haruo; Miyara, Akio; Ikegami, Yasuyuki; Nakaoka, Tsutomu

    1996-05-01

    A performance analysis of an OTEC plant using an integrated hybrid cycle (I-H OTEC Cycle) has been conducted. The I-H OTEC cycle is a combination of a closed-cycle OTEC plant and a spray flash desalination plant. In an I-H OTEC cycle, warm sea water evaporates the liquid ammonia in the OTEC evaporator, then enters the flash chamber and evaporates itself. The evaporated steam enters the desalination condenser and is condensed by the cold sea water passed through the OTEC condenser. The optimization of the I-H OTEC cycle is analyzed by the method of steepest descent. The total heat transfer area of heat exchangers per net power is used as an objective function. Numerical results are reported for a 10 MW I-H OTEC cycle with plate-type heat exchangers and ammonia as working fluid. The results are compared with those of a joint hybrid OTEC cycle (J-H OTEC Cycle).

  15. Total Space Heating Water Heating Cook-

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

    Tables Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ... 634 578 46 1 Q 116.4 106.3...

  16. Metal-Organic Heat Carrier Nanofluids

    SciTech Connect (OSTI)

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

    2013-09-01

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

  17. Fuel Cycle Subcommittee

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

    to NEAC Fuel Cycle Subcommittee Meeting of May 1, 2014 Washington, DC May 28, 2014 Al ... for the May 1, 2014 Fuel Cycle Subcommittee meeting and list of presenters is given below. ...

  18. Water Cycle Pilot Study

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

    1 Water Cycle Pilot Study To learn more about Earth's water cycle, the U.S. Department of Energy (DOE) has established a multi-laboratory science team representing five DOE ...

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

    SciTech Connect (OSTI)

    Wright, Steven Alan; Parma, Edward J., Jr.; Suo-Anttila, Ahti Jorma; Al Rashdan, Ahmad; Tsvetkov, Pavel Valeryevich; Vernon, Milton E.; Fleming, Darryn D.; Rochau, Gary Eugene

    2011-05-01

    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.

  20. ARM - The Hydrologic Cycle

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

    Hydrologic Cycle Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About ARM Global Warming FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans The Hydrologic Cycle The hydrologic cycle is the cycle through which water passes from sea to land and from land to sea. Water vapor enters the air through the evaporation of water. Water vapor in the air eventually condenses

  1. Heating apparatus

    SciTech Connect (OSTI)

    Page, V. J.

    1981-02-10

    A solar energy heating apparatus is described comprising means for concentrating solar energy incident thereon at an absorption station, an absorber located at the said absorption station for absorbing solar energy concentrated thereat, a first passageway associated with the said energy concentrating means for directing fluid so as to be preheated by the proportion of the incident energy absorbed by the said means, a second passageway associated with the absorber for effecting principal heating of fluid directed therethrough. The second passageway is such that on directing fluid through the first passageway it is initially preheated by the proportion of the incident energy absorbed by the energy concentrating means, the preheated fluid thereafter being directed to the second passageway where the principal heating takes place.

  2. Kalex Advanced Low Temp Geothemal Power Cycle | Department of Energy

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

    Kalex Advanced Low Temp Geothemal Power Cycle Kalex Advanced Low Temp Geothemal Power Cycle Kalex Advanced Low Temp Geothemal Power Cycle presentation at the April 2013 peer review meeting held in Denver, Colorado. kalex_low_temp_peer2013.pdf (173.69 KB) More Documents & Publications Osmotic Heat Engine for Energy Production from Low Temperature Geothemal Resources Chena Hot Springs Resort - Electric Power Generation Using Geothermal Fluid Coproduced from Oil and/or Gas Wells Single-well Low

  3. Hybrid solar central receiver for combined cycle power plant

    DOE Patents [OSTI]

    Bharathan, Desikan; Bohn, Mark S.; Williams, Thomas A.

    1995-01-01

    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.

  4. Hybrid solar central receiver for combined cycle power plant

    DOE Patents [OSTI]

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

    1995-05-23

    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.

  5. Organic Rankine Cycle for Light Duty Passenger Vehicles | Department of

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

    Energy for Light Duty Passenger Vehicles Organic Rankine Cycle for Light Duty Passenger Vehicles Dynamic model of organic Rankine cycle with R245fa working fluid and conservative component efficiencies predict power generation in excess of electrical accessory load demand under highway drive cycle deer11_hussain.pdf (688.58 KB) More Documents & Publications Vehicle Fuel Economy Improvement through Thermoelectric Waste Heat Recovery Automotive Thermoelectric Generator Design Issues

  6. A novel radio frequency assisted heat pump dryer

    SciTech Connect (OSTI)

    Marshall, M.G.; Metaxas, A.C.

    1999-09-01

    This paper compares an experimental heat pump batch dryer with the implementation of volumetric Radio Frequency (RF) heating, in the combination drying of crushed brick particulate. Results are presented showing overall improvements in drying. A simplified mathematical drying model including the RF energy source has been developed using mass and energy conservation, confirming the experimental results. Drying is a widespread, energy intensive industrial unit operation. The economics of a drying process operation largely depend upon the dryers performance and ultimately the cost of energy consumption. To enhance the performance of a drying system, the damp air stream that exits the drying chamber can be recycled to reclaim the enthalpy of evaporation that it carries, by using a heat pump (Hodgett, 1976). However, because the medium that dries is still warm air, this system also suffers from heat transfer limitations, particularly towards the falling drying rate period. Such limitations in drying performance can be overcome with the use of Radio Frequency (RF) energy which generates heat volumetrically within the wet material by the combined mechanisms of dipole rotation and conduction effects which speeds up the drying process (Metaxas et al, 1983). Despite the clear advantages that heat pumps and high frequency heating offer for drying, the combination of these two techniques until recently has not been studied (Kolly et al, 1990; Marshall et al, 1995).A series of experiments carried out comprising a motor driven heat pump which was retro-fitted with the ability of imparting RF energy into a material at various stages of the drying cycle are described and compared with a mathematical model.

  7. Power systems utilizing the heat of produced formation fluid

    DOE Patents [OSTI]

    Lambirth, Gene Richard

    2011-01-11

    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.

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

    Energy Savers [EERE]

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

  9. Heat exchanger

    DOE Patents [OSTI]

    Wolowodiuk, Walter

    1976-01-06

    A heat exchanger of the straight tube type in which different rates of thermal expansion between the straight tubes and the supply pipes furnishing fluid to those tubes do not result in tube failures. The supply pipes each contain a section which is of helical configuration.

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

    SciTech Connect (OSTI)

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

    2014-07-01

    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.

  11. Performance of supercritical CO{sub 2} Brayton cycle with additive gases at varying critical points for SFR application

    SciTech Connect (OSTI)

    Jeong, W. S.; Jeong, Y. H.

    2012-07-01

    The supercritical carbon dioxide Brayton cycle (S-CO{sub 2} cycle) has received attention as alternative to the energy conversion system for a Sodium-cooled Fast Reactor (SFR). The high cycle efficiency of S-CO{sub 2} cycle is attributed to significantly reduced compressor work. This is because the compressor operates like a pump in the vicinity of CO{sub 2} critical point. To make use of this feature, the minimum cycle operating range of S-CO{sub 2} cycle, which is the main compressor inlet condition, should be located close to the critical point of CO{sub 2}. This translated into that the critical point of CO{sub 2} is the limitation of the lowest cycle condition of S-CO{sub 2} cycles. To increase the flexibility and broaden the applicability of the cycle, changing the critical point of CO{sub 2} by mixing additive gases could be adopted. An increase in the efficiency of the S-CO{sub 2} cycle could be achieved by decreasing critical point of CO{sub 2}. In addition, increasing critical point of CO{sub 2} could be utilized to obtain improved cycle performances at ascending heat sink temperature of hot arid areas. Due to the rapid fluctuations of thermo-physical properties of gas mixtures near the critical point, an in-house cycle analysis code coupled to NIST property database was developed. Several gases were selected as potential additives through the screening process for thermal stability and chemical interaction with sodium. By using the developed cycle code, optimized cycles of each gas mixture were compared with the reference case of S-CO{sub 2} cycle. For decreased critical temperatures, CO{sub 2}-Xe and CO{sub 2}-Kr showed an increase in the total cycle efficiency. At increasing critical temperatures, the performance of CO{sub 2}-H{sub 2}S and CO{sub 2}-cyclohexane is superior to S-CO{sub 2}cycle when the compressor inlet temperature is above the critical temperature of CO{sub 2}. (authors)

  12. SUPERCRITICAL STEAM CYCLE FOR NUCLEAR POWER PLANT

    SciTech Connect (OSTI)

    Tsiklauri, Georgi V.; Talbert, Robert J.; Schmitt, Bruce E.; Filippov, Gennady A.; Bogojavlensky, Roald G.; Grishanin, Evgeny I.

    2005-07-01

    Revolutionary improvement of the nuclear plant safety and economy with light water reactors can be reached with the application of micro-fuel elements (MFE) directly cooled by a supercritical pressure light-water coolant-moderator. There are considerable advantages of the MFE as compared with the traditional fuel rods, such as: Using supercritical and superheated steam considerably increases the thermal efficiency of the Rankine cycle up to 44-45%. Strong negative coolant and void reactivity coefficients with a very short thermal delay time allow the reactor to shutdown quickly in the event of a reactivity or power excursion. Core melting and the creation of corium during severe accidents are impossible. The heat transfer surface area is larger by several orders of magnitude due to the small spherical dimensions of the MFE. The larger heat exchange surface significantly simplifies residual heat removal by natural convection and radiation from the core to a subsequent passive system of heat removal.

  13. Pipeline bottoming cycle study. Final report

    SciTech Connect (OSTI)

    Not Available

    1980-06-01

    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.

  14. Method and apparatus for fuel gas moisturization and heating

    DOE Patents [OSTI]

    Ranasinghe, Jatila; Smith, Raub Warfield

    2002-01-01

    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.

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

    SciTech Connect (OSTI)

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

    1998-07-01

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

  16. Fourier heat conduction as a phenomenon described within the scope of the second law

    SciTech Connect (OSTI)

    Jesudason, Christopher G.

    2014-12-10

    unfortunately linked to mechanical reversibility, that has discouraged such an association. The modeling is based on an application of a 'recoverable transition', defined and developed earlier on ideas derived from thermal desorption of particles from a surface where the Fourier heat conduction process is approximated as a series of such desorption processes. We recall that the original Carnot engine required both adiabatic and isothermal steps to complete the zero entropy cycle, and this construct lead to the consequent deduction that any Second law statement that refers to heat-work conversion processes are only globally relevant. Here, on the other hand, we examine Fourier heat conduction from MD simulation and model this process as a zero-entropy forward scattering process relative to each of the atoms in the lattice chain being treated as a system where the Carnot cycle can be applied individually. The equations developed predicts the 'work' done to be equal to the energy transfer rate. 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.

  17. New Regenerative Cycle for Vapor Compression Refrigeration

    SciTech Connect (OSTI)

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

    2010-01-26

    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.

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

    SciTech Connect (OSTI)

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

    2005-05-31

    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.

  19. 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

    2011-11-01

    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.

  20. Show Me Ethanol LLC | Open Energy Information

    Open Energy Info (EERE)

    Show Me Ethanol LLC Jump to: navigation, search Name: Show Me Ethanol, LLC Place: Carrollton, Missouri Zip: 64633 Product: Developing an ethanol project in Carrollton, Missouri....

  1. Detroit Auto Show 2012 | Department of Energy

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

    Detroit Auto Show 2012 Detroit Auto Show 2012 Addthis 1 of 10 Energy Secretary Steven Chu with Chrysler Chief Executive Sergio Marchionne. Image: Hantz Leger (Energy Department ...

  2. CWS-Fired Residential Warm-Air Heating System. Quarterly report, November 1, 1988--January 31, 1989

    SciTech Connect (OSTI)

    Balsavich, J.; Becker, F.E.; Smolensky, L.A.

    1989-03-01

    Work continued on life-cycle testing, optimization, and refining of the second-generation furnace assembly as well as the auxiliary subsystems. Emphasis of combustor testing was to determine optimum size and location of air inlets in primary combustion chambers; it was found that using a single air inlet about 70 degrees upsteam from the agglomeration site produces a combustion efficiency of 99.0% while producing no agglomeration. The test of the fouling effect on heat exchanger performance showed a steady decrease in time of the overall heat transfer coefficient. Particle size distribution of fly ash in the baghouse showed 50% of the particles smaller than 11.2 microns.

  3. Northeast Home Heating Oil Reserve (NEHHOR) Weekly Trigger Report...

    Office of Environmental Management (EM)

    Weekly Trigger Report Northeast Home Heating Oil Reserve (NEHHOR) Weekly Trigger Report The weekly report for the current heating oil season shows the differential levels required ...

  4. Fuel Cycle Subcommittee

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

    to NEAC Fuel Cycle Subcommittee Meeting of October 30, 2014 Washington, DC December 1, 2014 Al Sattelberger (Chair), Carol Burns, Margaret Chu, Raymond Juzaitis, Chris Kouts, Sekazi Mtingwa, Ronald Omberg, Joy Rempe, Dominique Warin I. Introduction 1 The agenda for the October 30, 2014 Fuel Cycle Subcommittee meeting is given below. The meeting provided members an overview of various research efforts funded by the Department of Energy Office of Nuclear Energy (DOE-NE) Fuel Cycle Technologies

  5. Fuel Cycle Subcommittee

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

    Report to NEAC Fuel Cycle Subcommittee Meeting of October 22, 2015 Washington, DC December 7, 2015 Al Sattelberger (Chair), Carol Burns, Margaret Chu, Raymond Juzaitis, Chris Kouts, Sekazi Mtingwa, Ronald Omberg, Joy Rempe, Dominique Warin 2 I. Introduction The agenda for the October 22, 2015 Fuel Cycle Subcommittee meeting is given below. The meeting provided members an overview of several research efforts funded by the DOE Office of Nuclear Energy's Fuel Cycle Technologies (FCT) program and

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

    SciTech Connect (OSTI)

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

    2010-09-15

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

  7. 10 MWe power cycle

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

    MWe power cycle - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy ...

  8. Waste heat driven absorption refrigeration process and system

    DOE Patents [OSTI]

    Wilkinson, William H.

    1982-01-01

    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.

  9. A two-dimensional model for the heat transfer on the external circuit of a Stirling engine for a dish/Stirling system

    SciTech Connect (OSTI)

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

    1998-07-01

    In this paper the {kappa}-{var{underscore}epsilon} turbulent model for the incompressible fluid flow has been used to describe the heat transfer and gas dynamical processes on the external circuit of a Stirling Engine as used on a Solar Dish/Stirling System. The problem considered, in this work for a cavity-type heat receiver of the Stirling Engine, is that of the heat transfer in the body of the shell of the heat exchangers of the engine due to the thermal conductivity, the convective heat transfer between the working fluid and the walls of the engine internal gas circuit and the heat transfer due to the forced convection of the air in the cavity and in the attached air domain. The boundary conditions employed on the engines internal circuit were obtained using the developed one-dimensional second level mathematical model of the engine working cycle. Physical models for the distribution of the solar insolation on the bottom and side walls of the heat receiver have been taken into account and the temperature fields for the heat receiver and the air velocity have been obtained for the case when the heat receiver is affected by wind. The numerical results show that it is in the region of the boundary of the input window of the heat receiver where there is the largest reduction in the temperature in the shell of the heat exchangers and this is due to the convection of the air.

  10. Heat transfer and heat exchangers reference handbook

    SciTech Connect (OSTI)

    Not Available

    1991-01-15

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

  11. Heating systems for heating subsurface formations

    DOE Patents [OSTI]

    Nguyen, Scott Vinh; Vinegar, Harold J.

    2011-04-26

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

  12. Heat exchanger

    DOE Patents [OSTI]

    Brackenbury, P.J.

    1983-12-08

    A heat exchanger comparising a shell attached at its open end to one side of a tube sheet and a detachable head connected to the other side of said tube sheet. The head is divided into a first and second chamber in fluid communication with a nozzle inlet and nozzle outlet, respectively, formed in said tube sheet. A tube bundle is mounted within said shell and is provided with inlets and outlets formed in said tube sheet in communication with said first and second chambers, respectively.

  13. Heat exchanger

    DOE Patents [OSTI]

    Brackenbury, Phillip J.

    1986-01-01

    A heat exchanger comparising a shell attached at its open end to one side of a tube sheet and a detachable head connected to the other side of said tube sheet. The head is divided into a first and second chamber in fluid communication with a nozzle inlet and nozzle outlet, respectively, formed in said tube sheet. A tube bundle is mounted within said shell and is provided with inlets and outlets formed in said tube sheet in communication with said first and second chambers, respectively.

  14. Heat exchanger

    DOE Patents [OSTI]

    Brackenbury, Phillip J.

    1986-04-01

    A heat exchanger comparising a shell attached at its open end to one side of a tube sheet and a detachable head connected to the other side of said tube sheet. The head is divided into a first and second chamber in fluid communication with a nozzle inlet and nozzle outlet, respectively, formed in said tube sheet. A tube bundle is mounted within said shell and is provided with inlets and outlets formed in said tube sheet in communication with said first and second chambers, respectively.

  15. Life Cycle Cost Estimate

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

    1997-03-28

    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.

  16. Power Plant Cycling Costs

    SciTech Connect (OSTI)

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

    2012-07-01

    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.

  17. Analysis of a graphite foam-NaCl latent heat storage system for...

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

    Analysis of a graphite foam-NaCl latent heat storage system for supercritical CO2 power cycles for concentrated solar power Title Analysis of a graphite foam-NaCl latent heat...

  18. WASTE HEAT-TO-POWER IN SMALL-SCALE INDUSTRY USING SCROLL EXPANDER...

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

    WASTE HEAT-TO-POWER 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 ...

  19. Dehumidifying Heat Pipes | Department of Energy

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

    Dehumidifying Heat Pipes Dehumidifying Heat Pipes In order to make a room comfortable in hot, humid climates, an air conditioner must lower the indoor humidity level as well as the air temperature. If an air conditioner fails to lower the humidity adequately, the air will be cool, but will feel uncomfortably damp. Inappropriately sized air conditioners are prone to this problem; large units quickly cool the air, but cycle off before they can properly dehumidify it. In extremely humid climates,

  20. Li-Ion polymer cells thermal property changes as a function of cycle-life

    SciTech Connect (OSTI)

    Maleki, Hossein; Wang, Hsin; Porter, Wallace D; Hallmark, Jerry

    2014-01-01

    The impact of elevated temperature chargeedischarge cycling on thermal conductivity (K-value) of Lithium Ion Polymer (LIP) cells of various chemistries from three different manufacturers was investigated. These included high voltage (Graphite/LiCoO2:3.0e4.35 V), wide voltage (Si:C/LiCoO2:2.7e4.35 V) and conventional (Graphite/LiCoO2:3.0e4.2 V) chemistries. Investigation results show limited variability within the in-plane and through-plane K-values for the fresh cells with graphite-based anodes from all three suppliers. After 500 cycles at 45 C, in-plane and through-plane K-values of the high voltage cells reduced less vs. those for the wide voltage cells. Such results suggest that high temperature cycling could have a greater impact on thermal properties of Si:C cells than on the LIP cells with graphite (Gr) anode cells we tested. This difference is due to the excess swelling of Si:C-anode based cells vs. Gr-anode cells during cycling, especially at elevated temperatures. Thermal modeling is used to evaluate the impact of K-value changes, due to cycles at 45 C, on the cells internal heat propagation under internal short circuit condition that leads to localized meltdown of the separator.

  1. 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

    2012-06-01

    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.

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

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

    Bunsen Wong during the Thermochemical Energy Storage Workshop on January 8, 2013. PDF icon ... Packaging Components Thermochemical Energy Storage 2014 SunShot Initiative Portfolio ...

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

    Broader source: Energy.gov [DOE]

    This presentation summarizes the introduction given by Bunsen Wong during the Thermochemical Energy Storage Workshop on January 8, 2013.

  4. Organic flash cycles for efficient power production

    DOE Patents [OSTI]

    Ho, Tony; Mao, Samuel S.; Greif, Ralph

    2016-03-15

    This disclosure provides systems, methods, and apparatus related to an Organic Flash Cycle (OFC). In one aspect, a modified OFC system includes a pump, a heat exchanger, a flash evaporator, a high pressure turbine, a throttling valve, a mixer, a low pressure turbine, and a condenser. The heat exchanger is coupled to an outlet of the pump. The flash evaporator is coupled to an outlet of the heat exchanger. The high pressure turbine is coupled to a vapor outlet of the flash evaporator. The throttling valve is coupled to a liquid outlet of the flash evaporator. The mixer is coupled to an outlet of the throttling valve and to an outlet of the high pressure turbine. The low pressure turbine is coupled to an outlet of the mixer. The condenser is coupled to an outlet of the low pressure turbine and to an inlet of the pump.

  5. Heat pipe methanator

    DOE Patents [OSTI]

    Ranken, William A.; Kemme, Joseph E.

    1976-07-27

    A heat pipe methanator for converting coal gas to methane. Gravity return heat pipes are employed to remove the heat of reaction from the methanation promoting catalyst, transmitting a portion of this heat to an incoming gas pre-heat section and delivering the remainder to a steam generating heat exchanger.

  6. Structural and Evolutionary Analyses Show Unique Stabilization...

    Office of Scientific and Technical Information (OSTI)

    Title: Structural and Evolutionary Analyses Show Unique Stabilization Strategies in the Type IV Pili of Clostridium difficile Authors: Piepenbrink, Kurt H. ; Maldarelli, Grace A. ; ...

  7. Development of an Ionic-Liquid Absorption Heat Pump

    SciTech Connect (OSTI)

    Holcomb, Don

    2011-03-29

    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.

  8. PBMR as an Ideal Heat Source for High-Temperature Process Heat Applications

    SciTech Connect (OSTI)

    Correia, Michael; Greyvenstein, Renee; Silady, Fred; Penfield, Scott

    2006-07-01

    The Pebble Bed Modular Reactor (PBMR) is an advanced helium-cooled, graphite-moderated High Temperature Gas-cooled Reactor (HTGR). A 400 MWt PBMR Demonstration Power Plant (DPP) for the production of electricity is being developed in South Africa. This PBMR technology is also an ideal heat source for process heat applications, including Steam Methane Reforming, steam for Oil Sands bitumen recovery, Hydrogen Production and co-generation (process heat and/or electricity and/or process steam) for petrochemical industries. The cycle configuration used to transport the heat of the reactor to the process plant or to convert the reactor's heat into electricity or steam directly influences the cycle efficiency and plant economics. The choice of cycle configuration depends on the process requirements and is influenced by practical considerations, component and material limitations, maintenance, controllability, safety, performance, risk and cost. This paper provides an overview of the use of a PBMR reactor for process applications and possible cycle configurations are presented for applications which require high temperature process heat and/or electricity. (authors)

  9. Status report on survey of alternative heat pumping technologies

    SciTech Connect (OSTI)

    Fischer, S.

    1998-07-01

    The Department of Energy is studying alternative heat pumping technologies to identify possible cost effective alternatives to electric driven vapor compression heat pumps, air conditioners, and chillers that could help reduce CO{sub 2} emissions. Over thirty different technologies are being considered including: engine driven systems, fuel cell powered systems, and alternative cycles. Results presented include theoretical efficiencies for all systems as well as measured performance of some commercial, prototype, or experimental systems. Theoretical efficiencies show that the alternative electric-driven technologies would have HSPFs between 4 and 8 Btu/Wh (1.2 to 2.3 W/W) and SEERs between 3 and 9.5 Btu/Wh (0.9 and 2.8 W/W). Gas-fired heat pump technologies have theoretical seasonal heating gCOPs from 1.1 to 1.7 and cooling gCOPs from 0.95 to 1.6 (a SEER 12 Btu/Wh electric air conditioner has a primary energy efficiency of approximately 1.4 W/W).

  10. Dual source heat pump

    DOE Patents [OSTI]

    Ecker, Amir L.; Pietsch, Joseph A.

    1982-01-01

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

  11. Segmented heat exchanger

    DOE Patents [OSTI]

    Baldwin, Darryl Dean; Willi, Martin Leo; Fiveland, Scott Byron; Timmons, Kristine Ann

    2010-12-14

    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.

  12. Terrestrial Carbon Cycle

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

    cycle Terrestrial Carbon Cycle "Only about half of the CO2 released into the atmosphere by human activities currently resides in the atmosphere, the rest absorbed on land and in the oceans. The period over which the carbon will be sequestered is unclear, and the efficiency of future sinks is unknown." US Carbon Cycle Research Plan "We" desire to be able to predict the future spatial and temporal distribution of sources and sinks of atmospheric CO2 and their interaction

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

    SciTech Connect (OSTI)

    Chang, Ho-Myung; Park, Jae Hoon; Gwak, Kyung Hyun; Choe, Kun Hyung

    2014-01-29

    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.

  14. The Future of Home Heating | Department of Energy

    Office of Environmental Management (EM)

    Technical Information Exchange on Pyrolysis Oil: Potential for a Renewab;e Heating Oil Substation Fuel in New England Performance of Biofuels and Biofuel Blends A Life-Cycle ...

  15. 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.

  16. Duty Cycle Software Model

    Energy Science and Technology Software Center (OSTI)

    2010-12-31

    The Software consists of code which is capable of processing a large volume of data to create a “duty cycle” which is representative of how equipment will function under certain conditions.

  17. Power Plant Cycling Costs

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

    ... Intertek APTECH has organized the cycling cost data in consultation with NREL and WECC by the following eight generator plant types: 1. Small coal-fired sub-critical steam (35-299 ...

  18. Electrically heated DPF start-up strategy

    SciTech Connect (OSTI)

    Gonze, Eugene V; Ament, Frank

    2012-04-10

    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.

  19. 2016 Washington Auto Show | Department of Energy

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

    Washington Auto Show 2016 Washington Auto Show Addthis 1 of 20 Energy Secretary Ernest Moniz sits in the driver's seat of the all-electric Chevrolet Bolt at the Washington Auto Show. When it debuts on the road later this year, the Bolt will offer drivers about 200 miles of electric range. Image: Simon Edelman, Energy Department Date taken: 2016-01-21 09:45 2 of 20 The 2016 next-generation Chevrolet Volt builds on the success of its previous version, which was the first plug-in hybrid electric

  20. Post-Show Tips | Department of Energy

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

    Post-Show Tips Post-Show Tips These guidelines are designed to help you with the post-show process. This page includes tips for tearing down your exhibit, shipping the exhibit, and collecting your bills. "Tearing Down" the Exhibit Take down the display and roll up display graphics with image-side out and using sheet spacers to separate graphics. Take note of any repairs that need to be made to the display-these will need to be reported to Marilyn Burgess after the event. Pack up unused

  1. Pre-Show Checklist | Department of Energy

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

    Pre-Show Checklist Pre-Show Checklist Before you leave for your event, you should check that you are prepared and ready to go. This checklist was designed to remind you of the steps you are required to take before leaving for your event. Exhibit (Booth) Space and EERE Display Reserved Reserve exhibit space with the show as soon as possible. The longer you wait, the more expensive exhibit space will be. The purchase of a 10' x 10' exhibit space (typically, the smallest exhibit space available) is

  2. 2013 Washington Auto Show | Department of Energy

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

    Washington Auto Show 2013 Washington Auto Show Addthis 1 of 10 While at the Washington Auto Show, Energy Secretary Steven Chu visited Nissan to see the 2013 Leaf. | Photo courtesy of Sarah Gerrity, Energy Department. Date taken: 2013-01-31 13:50 2 of 10 The new Nissan Leaf is being built at the company's Smyrna, Tennessee, Vehicle Assembly Plant -- helping to cut the price of its electric vehicle. | Photo courtesy of Sarah Gerrity, Energy Department. Date taken: 2013-01-31 13:49 3 of 10 Energy

  3. Forest Carbon Cycle

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

    forest carbon cycle Forest Carbon Cycle Terrestrial carbon stocks above- and belowground (in humus and litter layers, woody debris, and mineral soil) are not only sensitive to physical environmental controls (e.g., temperature, precipitation, soil moisture) but also to land use history/management, disturbance, "quality" of carbon input (a reflection of plant carbon allocation and species controls), and the microbial community. The relative importance of these controls on soil carbon

  4. Wetland (peat) Carbon Cycle

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

    wetland peat carbon cycle Wetland (peat) Carbon Cycle Methane (CH4) is an important greenhouse gas, twenty times more potent than CO2, but atmospheric concentrations of CH4 under future climate change are uncertain. This is in part because many climate-sensitive ecosystems release both CH4 and carbon dioxide (CO2) and it is unknown how these systems will partition future releases of carbon to the atmosphere. Ecosystem observations of CH4 emissions lack mechanistic links to the processes that

  5. Operation and analysis of a supercritical CO2 Brayton cycle.

    SciTech Connect (OSTI)

    Wright, Steven Alan; Radel, Ross F.; Vernon, Milton E.; Pickard, Paul S.; Rochau, Gary Eugene

    2010-09-01

    Sandia National Laboratories is investigating advanced Brayton cycles using supercritical working fluids for use with solar, nuclear or fossil heat sources. The focus of this work has been on the supercritical CO{sub 2} cycle (S-CO2) which has the potential for high efficiency in the temperature range of interest for these heat sources, and is also very compact, with the potential for lower capital costs. The first step in the development of these advanced cycles was the construction of a small scale Brayton cycle loop, funded by the Laboratory Directed Research & Development program, to study the key issue of compression near the critical point of CO{sub 2}. This document outlines the design of the small scale loop, describes the major components, presents models of system performance, including losses, leakage, windage, compressor performance, and flow map predictions, and finally describes the experimental results that have been generated.

  6. International Builders' Show | Department of Energy

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

    Builders' Show International Builders' Show February 14, 2008 - 11:29am Addthis Remarks as Prepared for Delivery by Secretary Bodman Thank you, Andy, and thank you all for being here. The world has reached an energy crossroads. Rising global energy demand and the need for more environmentally-responsible energy production and consumption have presented us with a number of global challenges that require global solutions. Every American has a role to play in meeting these challenges. And that's

  7. Effect of organics on nuclear cycles

    SciTech Connect (OSTI)

    Riddle, J.M. . Chemistry Services Section)

    1992-07-01

    Organics entering the nuclear cycle undergo hydrolysis or radiolysis and form carboxylic acids, acetic, formic, and propionic acids being the most prominent. Sequestered sulfur, halogens, metal species, and silica may also be released. The corrosion effects of halogens and sulfate are reasonably well understood. Historically, organic acids at low levels (e.g., 10 to 50 ppb) in nuclear cycles have been viewed as a nuisance or as potentially detrimental. This study reviews literature references of the effects of organics in nuclear cycles. Sources of organics and corrosion effects on plant materials are given from various references. Acetate can neutralize caustic in PWR steam generator crevices, whereas formate and oxalate as sodium salts can decompose to sodium carbonate. Sodium carbonate in crevices hydrolyzes to carbon dioxide and sodium hydroxide, which promotes SCC and IGA of Alloy 600. Formate and oxalate can act as oxygen scavengers in the BWR cycle and mitigate IGSCC of austenitic stainless steel. No firm evidence exists that organic acids have caused corrosion in turbines, piping, or heat exchangers in nuclear cycles, although organic acids at high levels can cause specific corrosion effects as a result of low pH.

  8. Conceptual design and techno-economic assessment of integrated solar combined cycle system with DSG technology

    SciTech Connect (OSTI)

    Nezammahalleh, H.; Farhadi, F.; Tanhaemami, M.

    2010-09-15

    Direct steam generation (DSG) in parabolic trough collectors causes an increase to competitiveness of solar thermal power plants (STPP) by substitution of oil with direct steam generation that results in lower investment and operating costs. In this study the integrated solar combined cycle system with DSG technology is introduced and techno-economic assessment of this plant is reported compared with two conventional cases. Three considered cases are: an integrated solar combined cycle system with DSG technology (ISCCS-DSG), a solar electric generating system (SEGS), and an integrated solar combined cycle system with HTF (heat transfer fluid) technology (ISCCS-HTF). This study shows that levelized energy cost (LEC) for the ISCCS-DSG is lower than the two other cases due to reducing O and M costs and also due to increasing the heat to electricity net efficiency of the power plant. Among the three STPPs, SEGS has the lowest CO{sub 2} emissions, but it will operate during daytime only. (author)

  9. Beowawe Binary Bottoming Cycle

    Broader source: Energy.gov [DOE]

    Project objectives: Demonstrate the technical and economic feasibility of electricity generation from the nonconventional geothermal resources of 205°F by extracting waste heat from the brine to power a binary power plant.

  10. An analytical approach to multi-cylinder regenerative machines with application to 3-cylinder heat-aided Stirling heat pump

    SciTech Connect (OSTI)

    Yagyu, Sumio; Fujishima, Ichiro; Corey, J.; Isshiki, Naotsugu

    1996-12-31

    This paper describes a method for analysis and optimization of multi-cylinder regenerative machines. The authors have devised this method in a project at KUBOTA to develop an improved gas engine-driven heat pump using both shaft power and exhaust heat sources. Based on combinations of included Stirling cycles, this analytical approach allows use of well-established and validated Stirling simulation models to optimize partial systems. The technique further provides a method of integrating such optimal partial-system Stirling cycles into a complex combination system. It is shown that this remains an optimum solution for the three-cylinder heat-assisted heat pump case. Results from hardware tests of the main Stirling heat pump cycle (2-cylinders) are given and compared with analytical expectations using Sage simulation code. This is extended to validate Sage modeling of 3-cylinder machines.