National Library of Energy BETA

Sample records for approximate heat rates

  1. ARM - Measurement - Radiative heating rate

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

    govMeasurementsRadiative heating rate ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Radiative heating rate The heating rate due to the divergence of long and shortwave radiative flux. Categories Radiometric, Atmospheric State Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a

  2. Combined Retrieval, Microphysical Retrievals and Heating Rates

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

    Feng, Zhe

    2013-02-22

    Microphysical retrievals and heating rates from the AMIE/Gan deployment using the PNNL Combined Retrieval.

  3. Combined Retrieval, Microphysical Retrievals and Heating Rates

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

    Feng, Zhe

    Microphysical retrievals and heating rates from the AMIE/Gan deployment using the PNNL Combined Retrieval.

  4. Combined Retrieval, Microphysical Retrievals and Heating Rates...

    Office of Scientific and Technical Information (OSTI)

    Shortwave broadband total upwelling irradiance; Liquid water content; Liquid water path; Radiative heating rate Dataset File size NAView Dataset View Dataset DOI: 10.5439116949

  5. MULTI-SCALE MODELING AND APPROXIMATION ASSISTED OPTIMIZATION OF BARE TUBE HEAT EXCHANGERS

    SciTech Connect (OSTI)

    Bacellar, Daniel; Ling, Jiazhen; Aute, Vikrant; Radermacher, Reinhard; Abdelaziz, Omar

    2014-01-01

    Air-to-refrigerant heat exchangers are very common in air-conditioning, heat pump and refrigeration applications. In these heat exchangers, there is a great benefit in terms of size, weight, refrigerant charge and heat transfer coefficient, by moving from conventional channel sizes (~ 9mm) to smaller channel sizes (< 5mm). This work investigates new designs for air-to-refrigerant heat exchangers with tube outer diameter ranging from 0.5 to 2.0mm. The goal of this research is to develop and optimize the design of these heat exchangers and compare their performance with existing state of the art designs. The air-side performance of various tube bundle configurations are analyzed using a Parallel Parameterized CFD (PPCFD) technique. PPCFD allows for fast-parametric CFD analyses of various geometries with topology change. Approximation techniques drastically reduce the number of CFD evaluations required during optimization. Maximum Entropy Design method is used for sampling and Kriging method is used for metamodeling. Metamodels are developed for the air-side heat transfer coefficients and pressure drop as a function of tube-bundle dimensions and air velocity. The metamodels are then integrated with an air-to-refrigerant heat exchanger design code. This integration allows a multi-scale analysis of air-side performance heat exchangers including air-to-refrigerant heat transfer and phase change. Overall optimization is carried out using a multi-objective genetic algorithm. The optimal designs found can exhibit 50 percent size reduction, 75 percent decrease in air side pressure drop and doubled air heat transfer coefficients compared to a high performance compact micro channel heat exchanger with same capacity and flow rates.

  6. Broadband Heating Rate Profile Project (BBHRP) - SGP ripbe1mcfarlane

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

    Riihimaki, Laura; Shippert, Timothy

    2014-11-05

    The objective of the ARM Broadband Heating Rate Profile (BBHRP) Project is to provide a structure for the comprehensive assessment of our ability to model atmospheric radiative transfer for all conditions. Required inputs to BBHRP include surface albedo and profiles of atmospheric state (temperature, humidity), gas concentrations, aerosol properties, and cloud properties. In the past year, the Radiatively Important Parameters Best Estimate (RIPBE) VAP was developed to combine all of the input properties needed for BBHRP into a single gridded input file. Additionally, an interface between the RIPBE input file and the RRTM was developed using the new ARM integrated software development environment (ISDE) and effort was put into developing quality control (qc) flags and provenance information on the BBHRP output files so that analysis of the output would be more straightforward. This new version of BBHRP, sgp1bbhrpripbeC1.c1, uses the RIPBE files as input to RRTM, and calculates broadband SW and LW fluxes and heating rates at 1-min resolution using the independent column approximation. The vertical resolution is 45 m in the lower and middle troposphere to match the input cloud properties, but is at coarser resolution in the upper atmosphere. Unlike previous versions, the vertical grid is the same for both clear-sky and cloudy-sky calculations.

  7. Broadband Heating Rate Profile Project (BBHRP) - SGP ripbe370mcfarlane

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

    Riihimaki, Laura; Shippert, Timothy

    2014-11-05

    The objective of the ARM Broadband Heating Rate Profile (BBHRP) Project is to provide a structure for the comprehensive assessment of our ability to model atmospheric radiative transfer for all conditions. Required inputs to BBHRP include surface albedo and profiles of atmospheric state (temperature, humidity), gas concentrations, aerosol properties, and cloud properties. In the past year, the Radiatively Important Parameters Best Estimate (RIPBE) VAP was developed to combine all of the input properties needed for BBHRP into a single gridded input file. Additionally, an interface between the RIPBE input file and the RRTM was developed using the new ARM integrated software development environment (ISDE) and effort was put into developing quality control (qc) flags and provenance information on the BBHRP output files so that analysis of the output would be more straightforward. This new version of BBHRP, sgp1bbhrpripbeC1.c1, uses the RIPBE files as input to RRTM, and calculates broadband SW and LW fluxes and heating rates at 1-min resolution using the independent column approximation. The vertical resolution is 45 m in the lower and middle troposphere to match the input cloud properties, but is at coarser resolution in the upper atmosphere. Unlike previous versions, the vertical grid is the same for both clear-sky and cloudy-sky calculations.

  8. Spatially resolved heat release rate measurements in turbulent premixed flames

    SciTech Connect (OSTI)

    Ayoola, B.O.; Kaminski, C.F.; Balachandran, R.; Mastorakos, E.; Frank, J.H.

    2006-01-01

    Heat release rate is a fundamental property of great importance for the theoretical and experimental elucidation of unsteady flame behaviors such as combustion noise, combustion instabilities, and pulsed combustion. Investigations of such thermoacoustic interactions require a reliable indicator of heat release rate capable of resolving spatial structures in turbulent flames. Traditionally, heat release rate has been estimated via OH or CH radical chemiluminescence; however, chemiluminescence suffers from being a line-of-sight technique with limited capability for resolving small-scale structures. In this paper, we report spatially resolved two-dimensional measurements of a quantity closely related to heat release rate. The diagnostic technique uses simultaneous OH and CH{sub 2}O planar laser-induced fluorescence (PLIF), and the pixel-by-pixel product of the OH and CH{sub 2}O PLIF signals has previously been shown to correlate well with local heat release rates. Results from this diagnostic technique, which we refer to as heat release rate imaging (HR imaging), are compared with traditional OH chemiluminescence measurements in several flames. Studies were performed in lean premixed ethylene flames stabilized between opposed jets and with a bluff body. Correlations between bulk strain rates and local heat release rates were obtained and the effects of curvature on heat release rate were investigated. The results show that the heat release rate tends to increase with increasing negative curvature for the flames investigated for which Lewis numbers are greater than unity. This correlation becomes more pronounced as the flame gets closer to global extinction.

  9. Sensitivity of Radiative Fluxes and Heating Rates to Cloud Microphysics

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

    Sensitivity of Radiative Fluxes and Heating Rates to Cloud Microphysics S. F. Iacobellis and R. C. J. Somerville Scripps Institution of Oceanography University of California, San Diego La Jolla, California G. M. McFarquhar University of Illinois at Urbana-Champaign Urbana, Illinois D. L. Mitchell Desert Research Institute Reno, Nevada Introduction A single-column model (SCM) is used to examine the sensitivity of basic quantities such as atmospheric radiative heating rates and surface and top of

  10. Status of the Broadband Heating Rate Profile (BBHRP) VAP

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

    Status of the Broadband Heating Rate Profile (BBHRP) VAP Mlawer, Eli Atmospheric & Environmental Research, Inc. Clough, Shepard Atmospheric and Environmental Research Delamere, Jennifer Atmospheric and Environmental Research, Inc. Miller, Mark Brookhaven National Laboratory Johnson, Karen Brookhaven National Laboratory Troyan, David Brookhaven National Laboratory Jensen, Michael Brookhaven National Laboratory Shippert, Timothy Pacific Northwest National Laboratory Long, Chuck Pacific

  11. High heating rate thermal desorption for molecular surface sampling

    DOE Patents [OSTI]

    Ovchinnikova, Olga S.; Van Berkel, Gary J.

    2016-03-29

    A method for analyzing a sample having at least one analyte includes the step of heating the sample at a rate of at least 10.sup.6 K/s to thermally desorb at least one analyte from the sample. The desorbed analyte is collected. The analyte can then be analyzed.

  12. Standby Rates for Combined Heat and Power Systems

    SciTech Connect (OSTI)

    Sedano, Richard; Selecky, James; Iverson, Kathryn; Al-Jabir, Ali

    2014-02-01

    Improvements in technology, low natural gas prices, and more flexible and positive attitudes in government and utilities are making distributed generation more viable. With more distributed generation, notably combined heat and power, comes an increase in the importance of standby rates, the cost of services utilities provide when customer generation is not operating or is insufficient to meet full load. This work looks at existing utility standby tariffs in five states. It uses these existing rates and terms to showcase practices that demonstrate a sound application of regulatory principles and ones that do not. The paper also addresses areas for improvement in standby rates.

  13. Selection, Evaluation, And Rating of Compact Heat exchangers

    Energy Science and Technology Software Center (OSTI)

    2014-10-07

    SEARCH determines and optimizes the design of a compact heat exchanger for specified process conditions. The user specifies process boundary conditions including the fluid state and flow rate and SEARCH will determine the optimum flow arrangement, channel geometry, and mechanical design for the unit. Fluids are modeled using NUST Refprop or tabulated values. A variety of thermal-hydraulic correlations are available including user-defined equations to accurately capture the heat transfer and pressure drop behavior of themore » process flows.« less

  14. Cloud Properties and Radiative Heating Rates for TWP

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

    Comstock, Jennifer

    2013-11-07

    A cloud properties and radiative heating rates dataset is presented where cloud properties retrieved using lidar and radar observations are input into a radiative transfer model to compute radiative fluxes and heating rates at three ARM sites located in the Tropical Western Pacific (TWP) region. The cloud properties retrieval is a conditional retrieval that applies various retrieval techniques depending on the available data, that is if lidar, radar or both instruments detect cloud. This Combined Remote Sensor Retrieval Algorithm (CombRet) produces vertical profiles of liquid or ice water content (LWC or IWC), droplet effective radius (re), ice crystal generalized effective size (Dge), cloud phase, and cloud boundaries. The algorithm was compared with 3 other independent algorithms to help estimate the uncertainty in the cloud properties, fluxes, and heating rates (Comstock et al. 2013). The dataset is provided at 2 min temporal and 90 m vertical resolution. The current dataset is applied to time periods when the MMCR (Millimeter Cloud Radar) version of the ARSCL (Active Remotely-Sensed Cloud Locations) Value Added Product (VAP) is available. The MERGESONDE VAP is utilized where temperature and humidity profiles are required. Future additions to this dataset will utilize the new KAZR instrument and its associated VAPs.

  15. Cloud Properties and Radiative Heating Rates for TWP

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

    Comstock, Jennifer

    A cloud properties and radiative heating rates dataset is presented where cloud properties retrieved using lidar and radar observations are input into a radiative transfer model to compute radiative fluxes and heating rates at three ARM sites located in the Tropical Western Pacific (TWP) region. The cloud properties retrieval is a conditional retrieval that applies various retrieval techniques depending on the available data, that is if lidar, radar or both instruments detect cloud. This Combined Remote Sensor Retrieval Algorithm (CombRet) produces vertical profiles of liquid or ice water content (LWC or IWC), droplet effective radius (re), ice crystal generalized effective size (Dge), cloud phase, and cloud boundaries. The algorithm was compared with 3 other independent algorithms to help estimate the uncertainty in the cloud properties, fluxes, and heating rates (Comstock et al. 2013). The dataset is provided at 2 min temporal and 90 m vertical resolution. The current dataset is applied to time periods when the MMCR (Millimeter Cloud Radar) version of the ARSCL (Active Remotely-Sensed Cloud Locations) Value Added Product (VAP) is available. The MERGESONDE VAP is utilized where temperature and humidity profiles are required. Future additions to this dataset will utilize the new KAZR instrument and its associated VAPs.

  16. Diagnosis system to improve heat rate in fossil power plants

    SciTech Connect (OSTI)

    Arroyo-Figueroa, G.; Villavicencio R., A.

    1996-05-01

    Today fossil fuel power plants is showing a trend toward full automation. This increases the difficulty for human operators to follow in detail the progress of power plants, and also limit the contribution of human operators to diagnostic task. Therefore, automated and intelligent fault diagnostic systems have been intensively investigated. Despite several successful examples of diagnostic systems, often called expert systems, the development task of a diagnostic system still remains empiric and is unique for each system. This paper discusses the design of a Diagnostic System to improve Heat Rate for fossil fuel power plant. The approach is characterized as an fault tree diagnostic system. The prototype of this system has showed the benefits and the feasibility of using this system to diagnose equipment in power plants.

  17. Minimally allowed neutrinoless double beta decay rates from approximate flavor symmetries

    SciTech Connect (OSTI)

    Jenkins, James [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States) and Northwestern University, Department of Physics and Astronomy, Evanston, Illinois 60208 (United States)

    2009-06-01

    Neutrinoless double beta decay ({beta}{beta}0{nu}) is among the only realistic probes of Majorana neutrinos. In the standard scenario, dominated by light neutrino exchange, the process amplitude is proportional to m{sub ee}, the e-e element of the Majorana mass matrix. Naively, current data allow for vanishing m{sub ee}, but this should be protected by an appropriate flavor symmetry. All such symmetries lead to mass matrices inconsistent with oscillation phenomenology. I perform a spurion analysis to break all possible Abelian symmetries that guarantee vanishing {beta}{beta}0{nu} rates and search for minimally allowed values. I survey 230 broken structures to yield m{sub ee} values and current phenomenological constraints under a variety of scenarios. This analysis also extracts predictions for both neutrino oscillation parameters and kinematic quantities. Assuming reasonable tuning levels, I find that m{sub ee}>4x10{sup -6} eV at 99% confidence. Bounds below this value might indicate the Dirac neutrino nature or the existence of new light (eV-MeV scale) degrees of freedom that can potentially be probed elsewhere.

  18. Minimally allowed beta beata 0_nu rates from approximate flavor symmetries

    SciTech Connect (OSTI)

    Jenkins, James [Los Alamos National Laboratory

    2008-01-01

    Neutrinoless double beta decay ({beta}{beta}0{nu}) is the only realistic probe of Majorana neutrinos. In the standard scenario, dominated by light neutrino exchange, the process amplitude is proportional to m{sub ee} , the e - e element of the Majorana mass matrix. This is expected to hold true for small {beta}{beta}{nu} rates ({Gamma}{sub {beta}{beta}0{nu}}), even in the presence of new physics. Naively, current data allows for vanishing m{sub ee} , but this should be protected by an appropriate flavor symmetry. All such symmetries lead to mass matrices inconsistent with oscillation phenomenology. Hence, Majorana neutrinos imply nonzero {Gamma}{sub {beta}{beta}0{nu}}. I perform a spurion analysis to break all possible abelian symmetries that guarantee {Gamma}{sub {beta}{beta}0{nu}} = 0 and search for minimally allowed m{sub ee} values. Specifically, I survey 259 broken structures to yield m{sub ee} values and current phenomenological constraints under a variety of scenarios. This analysis also extracts predictions for both neutrino oscillation parameters and kinematic quantities. Assuming reasonable tuning levels, I find that m{sub ee} > 4 x 10{sup -6} eV at 99% confidence. Bounds below this value would indicate the Dirac neutrino nature or the existence of new light (eV-MeV scale) degrees of freedom that can potentially be probed elsewhere. This limit can be raised by improvements in neutrino parameter measurements, particularly of the reactor mixing angle, depending on the best fit parameter values. Such improvements will also significantly constrain the available model space and aid in future constructions.

  19. Broadband Heating Rate Profile Project (BBHRP) - SGP 1bbhrpripbe1mcfarlane

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

    Riihimaki, Laura; Shippert, Timothy

    2014-11-05

    The objective of the ARM Broadband Heating Rate Profile (BBHRP) Project is to provide a structure for the comprehensive assessment of our ability to model atmospheric radiative transfer for all conditions. Required inputs to BBHRP include surface albedo and profiles of atmospheric state (temperature, humidity), gas concentrations, aerosol properties, and cloud properties. In the past year, the Radiatively Important Parameters Best Estimate (RIPBE) VAP was developed to combine all of the input properties needed for BBHRP into a single gridded input file. Additionally, an interface between the RIPBE input file and the RRTM was developed using the new ARM integrated software development environment (ISDE) and effort was put into developing quality control (qc) flags and provenance information on the BBHRP output files so that analysis of the output would be more straightforward. This new version of BBHRP, sgp1bbhrpripbeC1.c1, uses the RIPBE files as input to RRTM, and calculates broadband SW and LW fluxes and heating rates at 1-min resolution using the independent column approximation. The vertical resolution is 45 m in the lower and middle troposphere to match the input cloud properties, but is at coarser resolution in the upper atmosphere. Unlike previous versions, the vertical grid is the same for both clear-sky and cloudy-sky calculations.

  20. In-Cylinder Mechanisms of PCI Heat-Release Rate Control by Fuel Reactivity

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

    Stratification | Department of Energy Mechanisms of PCI Heat-Release Rate Control by Fuel Reactivity Stratification In-Cylinder Mechanisms of PCI Heat-Release Rate Control by Fuel Reactivity Stratification Explores in-cylinder mechanisms by which fuel reactivity stratification via a two fuel system affects premixed charge compression ignition heat release rate to achieve diesel-like efficiency deer11_kokjohn.pdf (3.98 MB) More Documents & Publications Heavy-Duty Low-Temperature and

  1. Heating from free-free absorption and the mass-loss rate of the progenitor stars to supernovae

    SciTech Connect (OSTI)

    Björnsson, C.-I.; Lundqvist, P. E-mail: peter@astro.su.se

    2014-06-01

    An accurate determination of the mass-loss rate of the progenitor stars to core-collapse supernovae is often limited by uncertainties pertaining to various model assumptions. It is shown that under conditions when the temperature of the circumstellar medium is set by heating due to free-free absorption, observations of the accompanying free-free optical depth allow a direct determination of the mass-loss rate from observed quantities in a rather model-independent way. The temperature is determined self-consistently, which results in a characteristic time dependence of the free-free optical depth. This can be used to distinguish free-free heating from other heating mechanisms. Since the importance of free-free heating is quite model dependent, this also makes possible several consistency checks of the deduced mass-loss rate. It is argued that the free-free absorption observed in SN 1993J is consistent with heating from free-free absorption. The deduced mass-loss rate of the progenitor star is, approximately, 10{sup –5} M {sub ☉} yr{sup –1} for a wind velocity of 10 km s{sup –1}.

  2. ARM - PI Product - Cloud Properties and Radiative Heating Rates for TWP

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

    ProductsCloud Properties and Radiative Heating Rates for TWP ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Cloud Properties and Radiative Heating Rates for TWP A cloud properties and radiative heating rates dataset is presented where cloud properties retrieved using lidar and radar observations are input into a radiative transfer model to compute radiative fluxes and heating rates at three ARM sites

  3. Analysis of Heat Rate Improvement Potential at Coal-Fired Power...

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

    Analysis of Heat Rate Improvement Potential at Coal-Fired Power Plants Release date: May 19, ... can vary depending in part on the type of equipment installed at a generating plant. ...

  4. Heat-Rate Improvement Obtained by Retubing Power-Plant Condenser Enhanced Tubes

    Energy Science and Technology Software Center (OSTI)

    1994-01-21

    A utility will only retube a condenser with enhanced tubes if the incremental cost of the enhanced tubes can be offset with reduced fuel costs. The reduced fuel cost is obtained for some units because of the higher heat-transfer coefficient of enhanced tubes. They lead to improved condenser performance measured by a lower condenser pressure and therefore a more efficient power plant. However, the higher haet-transfer coefficients do not always guarantee that enhanced tubes willmore » be more cost effective. Other issues must be considered such as the cooling-water flow reduction due to the increased pressure drop, the low-pressure turbine heat-rate variation with backpressure, and the cooling-water pump and system characteristics. These and other parameters must be considered to calculate the efficiency improvement of the power plant as commonly measured by the quantity known as the heat rate. Knowing the heat-rate improvement, the fuel cost, and the incremental increase of the enhanced tubes from the supplier, the payback time can be determined. This program calculates the heat-rate improvement that can be obtained by retubing a power plant condenser with enhanced tubes of a particular type called Korodense LPD made by Wolverine Tube, Inc. The fuel savings are easily established knowing the heat-rate improvement. All electrical utilities are potential users because a condenser is used as the heat sink for every power plant.« less

  5. An analysis of representative heating load lines for residential HSPF ratings

    SciTech Connect (OSTI)

    Rice, C. Keith; Shen, Bo; Shrestha, Som S.

    2015-07-01

    This report describes an analysis to investigate representative heating loads for single-family detached homes using current EnergyPlus simulations (DOE 2014a). Hourly delivered load results are used to determine binned load lines using US Department of Energy (DOE) residential prototype building models (DOE 2014b) developed by Pacific Northwest National Laboratory (PNNL). The selected residential single-family prototype buildings are based on the 2006 International Energy Conservation Code (IECC 2006) in the DOE climate regions. The resulting load lines are compared with the American National Standards Institute (ANSI)/Air-Conditioning, Heating, and Refrigeration Institute (AHRI) Standard 210/240 (AHRI 2008) minimum and maximum design heating requirement (DHR) load lines of the heating seasonal performance factor (HSPF) ratings procedure for each region. The results indicate that a heating load line closer to the maximum DHR load line, and with a lower zero load ambient temperature, is more representative of heating loads predicted for EnergyPlus prototype residential buildings than the minimum DHR load line presently used to determine HSPF ratings. An alternative heating load line equation was developed and compared to binned load lines obtained from the EnergyPlus simulation results. The effect on HSPF of the alternative heating load line was evaluated for single-speed and two-capacity heat pumps, and an average HSPF reduction of 16% was found. The alternative heating load line relationship is tied to the rated cooling capacity of the heat pump based on EnergyPlus autosizing, which is more representative of the house load characteristics than the rated heating capacity. The alternative heating load line equation was found to be independent of climate for the six DOE climate regions investigated, provided an adjustable zero load ambient temperature is used. For Region IV, the default DOE climate region used for HSPF ratings, the higher load line results in an ~28

  6. The Effect of Heat Treatments and Coatings on the Outgassing Rate of Stainless Steel Chambers

    SciTech Connect (OSTI)

    Mamum, Md Abdullah A.; Elmustafa, Abdelmageed A,; Stutzman, Marcy L.; Adderley, Philip A.; Poelker, Matthew

    2014-03-01

    The outgassing rates of four nominally identical 304L stainless steel vacuum chambers were measured to determine the effect of chamber coatings and heat treatments. One chamber was coated with titanium nitride (TiN) and one with amorphous silicon (a-Si) immediately following fabrication. One chamber remained uncoated throughout, and the last chamber was first tested without any coating, and then coated with a-Si following a series of heat treatments. The outgassing rate of each chamber was measured at room temperatures between 15 and 30 deg C following bakes at temperatures between 90 and 400 deg C. Measurements for bare steel showed a significant reduction in the outgassing rate by more than a factor of 20 after a 400 deg C heat treatment (3.5 x 10{sup 12} TorrL s{sup -1}cm{sup -2} prior to heat treatment, reduced to 1.7 x 10{ sup -13} TorrL s{sup -1}cm{sup -2} following heat treatment). The chambers that were coated with a-Si showed minimal change in outgassing rates with heat treatment, though an outgassing rate reduced by heat treatments prior to a-Si coating was successfully preserved throughout a series of bakes. The TiN coated chamber exhibited remarkably low outgassing rates, up to four orders of magnitude lower than the uncoated stainless steel. An evaluation of coating composition suggests the presence of elemental titanium which could provide pumping and lead to an artificially low outgassing rate. The outgassing results are discussed in terms of diffusion-limited versus recombination-limited processes.

  7. Microbase Cloud Products and Associated Heating Rates in the Tropical Western Pacific

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

    Microbase Cloud Products and Associated Heating Rates in the Tropical Western Pacific J. H. Mather and S. A. McFarlane Pacific Northwest National Laboratory Richland, Washington Introduction The microbase value added product (Miller et al. 2003) provides a standardized framework for calculating and storing continuous retrievals of cloud microphysical properties including liquid water content (LWC), ice water content (IWC), and cloud droplet size. Microbase is part of the larger broadband heating

  8. Kinetics of silicide formation over a wide range of heating rates spanning six orders of magnitude

    SciTech Connect (OSTI)

    Molina-Ruiz, Manel; Lopeanda, Aitor F.; Gonzalez-Silveira, Marta; Garcia, Gemma; Clavaguera-Mora, Maria T. [Grup de Nanomaterials i Microsistemes, Departament de Fsica, Universitat Autnoma de Barcelona, 08193 Bellaterra (Spain); Peral, Inma [ALBA Synchrotron Light Facility, 08290 Cerdanyola del Valls (Spain); Rodrguez-Viejo, Javier, E-mail: javier.rodriguez@uab.cat [Grup de Nanomaterials i Microsistemes, Departament de Fsica, Universitat Autnoma de Barcelona, 08193 Bellaterra (Spain); MATGAS Research Centre, UAB Campus, 08193 Bellaterra (Spain)

    2014-07-07

    Kinetic processes involving intermediate phase formation are often assumed to follow an Arrhenius temperature dependence. This behavior is usually inferred from limited data over narrow temperature intervals, where the exponential dependence is generally fully satisfied. However, direct evidence over wide temperature intervals is experimentally challenging and data are scarce. Here, we report a study of silicide formation between a 12?nm film of palladium and 15?nm of amorphous silicon in a wide range of heating rates, spanning six orders of magnitude, from 0.1 to 10{sup 5?}K/s, or equivalently more than 300?K of variation in reaction temperature. The calorimetric traces exhibit several distinct exothermic events related to interdiffusion, nucleation of Pd{sub 2}Si, crystallization of amorphous silicon, and vertical growth of Pd{sub 2}Si. Interestingly, the thickness of the initial nucleation layer depends on the heating rate revealing enhanced mass diffusion at the fastest heating rates during the initial stages of the reaction. In spite of this, the formation of the silicide strictly follows an Arrhenius temperature dependence over the whole temperature interval explored. A kinetic model is used to fit the calorimetric data over the complete heating rate range. Calorimetry is complemented by structural analysis through transmission electron microscopy and both standard and in-situ synchrotron X-ray diffraction.

  9. ITER Generic Diagnostic Upper Port Plug Nuclear Heating and Personnel Dose Rate Assesment

    SciTech Connect (OSTI)

    Russell E. Feder and Mahmoud Z. Youssef

    2009-01-28

    Neutronics analysis to find nuclear heating rates and personnel dose rates were conducted in support of the integration of diagnostics in to the ITER Upper Port Plugs. Simplified shielding models of the Visible-Infrared diagnostic and of a large aperture diagnostic were incorporated in to the ITER global CAD model. Results for these systems are representative of typical designs with maximum shielding and a small aperture (Vis-IR) and minimal shielding with a large aperture. The neutronics discrete-ordinates code ATTILA and SEVERIAN (the ATTILA parallel processing version) was used. Material properties and the 500 MW D-T volume source were taken from the ITER Brand Model MCNP benchmark model. A biased quadrature set equivelant to Sn=32 and a scattering degree of Pn=3 were used along with a 46-neutron and 21-gamma FENDL energy subgrouping. Total nuclear heating (neutron plug gamma heating) in the upper port plugs ranged between 380 and 350 kW for the Vis-IR and Large Aperture cases. The Large Aperture model exhibited lower total heating but much higher peak volumetric heating on the upper port plug structure. Personnel dose rates are calculated in a three step process involving a neutron-only transport calculation, the generation of activation volume sources at pre-defined time steps and finally gamma transport analyses are run for selected time steps. ANSI-ANS 6.1.1 1977 Flux-to-Dose conversion factors were used. Dose rates were evaluated for 1 full year of 500 MW DT operation which is comprised of 3000 1800-second pulses. After one year the machine is shut down for maintenance and personnel are permitted to access the diagnostic interspace after 2-weeks if dose rates are below 100 ?Sv/hr. Dose rates in the Visible-IR diagnostic model after one day of shutdown were 130 ?Sv/hr but fell below the limit to 90 ?Sv/hr 2-weeks later. The Large Aperture style shielding model exhibited higher and more persistent dose rates. After 1-day the dose rate was 230 ?Sv/hr but

  10. Recent Developments on the Broadband Heating Rate Profile Value-Added Product

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

    Recent Developments on the Broadband Heating Rate Profile Value-Added Product E. J. Mlawer, J. S. Delamere, and S. A. Clough Atmospheric and Environmental Research, Inc. Cambridge, Massachusetts M. A. Miller and K. L. Johnson Brookhaven National Laboratory Upton, New York T. R. Shippert and C. N. Long Pacific Northwest National Laboratory Richland, Washington R. G. Ellingson Florida State University Tallahassee, Florida M. H. Zhang State University of New York - Stony Brook Albany, New York R.

  11. 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.

  12. Building America Expert Meeting: Exploring the Disconnect Between Rated and Field Performance of Water Heating Systems

    Broader source: Energy.gov [DOE]

    Water heating represents a major residential energy end use, especially in highly efficient homes where space conditioning loads and energy use has been significantly reduced. Future efforts to reduce water heating energy use requires the development of an improved understanding of equipment performance, as well as recognizing system interactions related to the distribution system and the fixture use characteristics. By bringing together a group of water heating experts, we hope to advance the shared knowledge on key water heating performance issues and identify additional data needs that will further this critical research area.

  13. SISGR - In situ characterization and modeling of formation reactions under extreme heating rates in nanostructured multilayer foils

    SciTech Connect (OSTI)

    Hufnagel, Todd C.

    2014-06-09

    Materials subjected to extreme conditions, such as very rapid heating, behave differently than materials under more ordinary conditions. In this program we examined the effect of rapid heating on solid-state chemical reactions in metallic materials. One primary goal was to develop experimental techniques capable of observing these reactions, which can occur at heating rates in excess of one million degrees Celsius per second. One approach that we used is x-ray diffraction performed using microfocused x-ray beams and very fast x-ray detectors. A second approach is the use of a pulsed electron source for dynamic transmission electron microscopy. With these techniques we were able to observe how the heating rate affects the chemical reaction, from which we were able to discern general principles about how these reactions proceed. A second thrust of this program was to develop computational tools to help us understand and predict the reactions. From atomic-scale simulations were learned about the interdiffusion between different metals at high heating rates, and about how new crystalline phases form. A second class of computational models allow us to predict the shape of the reaction front that occurs in these materials, and to connect our understanding of interdiffusion from the atomistic simulations to measurements made in the laboratory. Both the experimental and computational techniques developed in this program are expected to be broadly applicable to a wider range of scientific problems than the intermetallic solid-state reactions studied here. For example, we have already begun using the x-ray techniques to study how materials respond to mechanical deformation at very high rates.

  14. Method and apparatus for active control of combustion rate through modulation of heat transfer from the combustion chamber wall

    DOE Patents [OSTI]

    Roberts, Jr., Charles E.; Chadwell, Christopher J.

    2004-09-21

    The flame propagation rate resulting from a combustion event in the combustion chamber of an internal combustion engine is controlled by modulation of the heat transfer from the combustion flame to the combustion chamber walls. In one embodiment, heat transfer from the combustion flame to the combustion chamber walls is mechanically modulated by a movable member that is inserted into, or withdrawn from, the combustion chamber thereby changing the shape of the combustion chamber and the combustion chamber wall surface area. In another embodiment, heat transfer from the combustion flame to the combustion chamber walls is modulated by cooling the surface of a portion of the combustion chamber wall that is in close proximity to the area of the combustion chamber where flame speed control is desired.

  15. Zero-point cooling and heating-rate measurements of a single {sup 88}Sr{sup +} ion

    SciTech Connect (OSTI)

    Letchumanan, V.; Wilpers, G.; Brownnutt, M.; Gill, P.; Sinclair, A. G.

    2007-06-15

    A single {sup 88}Sr{sup +} ion has been cooled to the zero point of its axial motion in a radio frequency endcap trap. A ground-state occupation probability of 98.6(8)% was achieved using resolved sideband laser cooling on the 674 nm {sup 2}S{sub 1/2}-{sup 2}D{sub 5/2} quadrupole transition. The ion's heating rate was measured to be 0.054(4) quanta/ms, implying a spectral density of electric field noise comparable to the other reported values, summarized in the paper by Deslauriers et al. [Phys. Rev. A 70, 043048 (2004)]. Low heating rates were only observed using a trap that had minimal exposure to atomic flux.

  16. 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

  17. Economic analysis of solar industrial process heat systems: a methodology to determine annual required revenue and internal rate of return

    SciTech Connect (OSTI)

    Dickinson, W.C.; Brown, K.C.

    1981-08-11

    To permit an economic evaluation of solar industrial process heat systems, a methodology was developed to determine the annual required revenue and the internal rate of return. First, a format is provided to estimate the solar system's installed cost, annual operating and maintenance expenses, and net annual solar energy delivered to the industrial process. Then an expression is presented that gives the annual required revenue and the price of solar energy. The economic attractiveness of the potential solar investment can be determined by comparing the price of solar energy with the price of fossil fuel, both expressed in levelized terms. This requires calculation of the internal rate of return on the solar investment or, in certain cases, the growth rate of return.

  18. Rapid heating tensile tests of hydrogen-charged high-energy-rate-forged 316L stainless steel

    SciTech Connect (OSTI)

    Mosley, W.C.

    1989-05-19

    316L stainless steel is a candidate material for construction of equipment that will be exposed to tritium. Proper design of the equipment will require an understanding of how tritium and its decay product helium affect mechanical properties. This memorandum describes results of rapid heating tensile testing of hydrogen-charged specimens of high-energy-rate-forged (HERF) 316L stainless steel. These results provide a data base for comparison with uncharged and tritium-charged-and-aged specimens to distinguish the effects of hydrogen and helium. Details of the experimental equipment and procedures and results for uncharged specimens were reported previously. 3 refs., 10 figs.

  19. The Stress Corrosion Crack Growth Rate of Alloy 600 Heat Affected Zones Exposed to High Purity Water

    SciTech Connect (OSTI)

    George A. Young; Nathan Lewis

    2003-04-05

    Grain boundary chromium carbides improve the resistance of nickel based alloys to primary water stress corrosion cracking (PWSCC). However, in weld heat affected zones (HAZ's), thermal cycles from fusion welding can solutionize beneficial grain boundary carbides, produce locally high residual stresses and strains, and promote PWSCC. The present research investigates the crack growth rate of an A600 HAZ as a function of test temperature. The A600 HAZ was fabricated by building up a gas-tungsten-arc-weld deposit of EN82H filler metal onto a mill-annealed A600 plate. Fracture mechanics based, stress corrosion crack growth rate testing was performed in high purity water between 600 F and 680 F at an initial stress intensity factor of 40 ksi {radical}in and at a constant electrochemical potential. The HAZ samples exhibited significant SCC, entirely within the HAZ at all temperatures tested. While the HAZ samples showed the same temperature dependence for SCC as the base material (HAZ: 29.8 {+-} 11.2{sub 95%} kcal/mol vs A600 Base: 35.3 {+-} 2.58{sub 95%} kcal/mol), the crack growth rates were {approx} 30X faster than the A600 base material tested at the same conditions. The increased crack growth rates of the HAZ is attributed to fewer intergranular chromium rich carbides and to increased plastic strain in the HAZ as compared to the unaffected base material.

  20. Heat Release Rates

    Broader source: Energy.gov [DOE]

    Supporting Technical Document for the Radiological Release Accident Investigation Report (Phase II Report)

  1. Research, development, and testing of a prototype two-stage low-input rate oil burner for variable output heating system applications

    SciTech Connect (OSTI)

    Krajewski, R.F.; Butcher, T.A.

    1997-09-01

    The use of a Two-Stage Fan Atomized Oil Burner (TSFAB) in space and water heating applications will have dramatic advantages in terms of it`s potential for a high Annual Fuel Utilization Efficiency (AFUE) and/or Energy Factor (EF) rating for the equipment. While demonstrations of a single rate burner in an actual application have already yielded sufficient confidence that space and domestic heating loads can be met at a single low firing rate, this represents only a narrow solution to the diverse nature of building space heating and domestic water loads that the industry must address. The mechanical development, proposed control, and testing of the Two-Stage burner is discussed in terms of near term and long term goals.

  2. ITER Generic Diagnostic Upper Port Plug Nuclear Heating and Personnel Dose Rate Assesment Neutronics Analysis using the ATTILA Discrete Ordinates Code

    SciTech Connect (OSTI)

    Russell Feder and Mahmoud Z. Yousef

    2009-05-29

    Neutronics analysis to find nuclear heating rates and personnel dose rates were conducted in support of the integration of diagnostics in to the ITER Upper Port Plugs. Simplified shielding models of the Visible-Infrared diagnostic and of the ECH heating system were incorporated in to the ITER global CAD model. Results for these systems are representative of typical designs with maximum shielding and a small aperture (Vis-IR) and minimal shielding with a large aperture (ECH). The neutronics discrete-ordinates code ATTILA and SEVERIAN (the ATTILA parallel processing version) was used. Material properties and the 500 MW D-T volume source were taken from the ITER Brand Model MCNP benchmark model. A biased quadrature set equivelant to Sn=32 and a scattering degree of Pn=3 were used along with a 46-neutron and 21-gamma FENDL energy subgrouping. Total nuclear heating (neutron plug gamma heating) in the upper port plugs ranged between 380 and 350 kW for the Vis-IR and ECH cases. The ECH or Large Aperture model exhibited lower total heating but much higher peak volumetric heating on the upper port plug structure. Personnel dose rates are calculated in a three step process involving a neutron-only transport calculation, the generation of activation volume sources at pre-defined time steps and finally gamma transport analyses are run for selected time steps. ANSI-ANS 6.1.1 1977 Flux-to-Dose conversion factors were used. Dose rates were evaluated for 1 full year of 500 MW DT operation which is comprised of 3000 1800-second pulses. After one year the machine is shut down for maintenance and personnel are permitted to access the diagnostic interspace after 2-weeks if dose rates are below 100 ?Sv/hr. Dose rates in the Visible-IR diagnostic model after one day of shutdown were 130 ?Sv/hr but fell below the limit to 90 ?Sv/hr 2-weeks later. The Large Aperture or ECH style shielding model exhibited higher and more persistent dose rates. After 1-day the dose rate was 230 ?Sv

  3. Tips: Heat Pumps | Department of Energy

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

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

  4. Heat release characteristics of stratified-charge rotary engines

    SciTech Connect (OSTI)

    Dimpelfeld, P.; Humke, A.

    1987-01-01

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

  5. Approximate option pricing

    SciTech Connect (OSTI)

    Chalasani, P.; Saias, I.; Jha, S.

    1996-04-08

    As increasingly large volumes of sophisticated options (called derivative securities) are traded in world financial markets, determining a fair price for these options has become an important and difficult computational problem. Many valuation codes use the binomial pricing model, in which the stock price is driven by a random walk. In this model, the value of an n-period option on a stock is the expected time-discounted value of the future cash flow on an n-period stock price path. Path-dependent options are particularly difficult to value since the future cash flow depends on the entire stock price path rather than on just the final stock price. Currently such options are approximately priced by Monte carlo methods with error bounds that hold only with high probability and which are reduced by increasing the number of simulation runs. In this paper the authors show that pricing an arbitrary path-dependent option is {number_sign}-P hard. They show that certain types f path-dependent options can be valued exactly in polynomial time. Asian options are path-dependent options that are particularly hard to price, and for these they design deterministic polynomial-time approximate algorithms. They show that the value of a perpetual American put option (which can be computed in constant time) is in many cases a good approximation to the value of an otherwise identical n-period American put option. In contrast to Monte Carlo methods, the algorithms have guaranteed error bounds that are polynormally small (and in some cases exponentially small) in the maturity n. For the error analysis they derive large-deviation results for random walks that may be of independent interest.

  6. Vapor pressure and evaporation rate of certain heat-resistant compounds in a vacuum at high temperatures

    SciTech Connect (OSTI)

    Bolgar, A.S.; Verkhoglyadova, T.S.; Samsonov, G.V.

    1985-02-01

    The vapor pressure and evaporation rate of borides of titanium, zirconium, and chrome and of strontium and carbides of titanium, zirconium, and chrome, molybdenum silicide and nitrides of titanium, niobium, and tantalum in a vacuum were studied. It is concluded that all subject compounds evaporate by molecular structures except AlB sub 12' which dissociates, losing the aluminum.

  7. Tips: Heat Pumps | Department of Energy

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

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

  8. Evaluating temperature and fuel stratification for heat-release rate control in a reactivity-controlled compression-ignition engine using optical diagnostics and chemical kinetics modeling

    SciTech Connect (OSTI)

    Musculus, Mark P. B.; Kokjohn, Sage L.; Reitz, Rolf D.

    2015-04-23

    We investigated the combustion process in a dual-fuel, reactivity-controlled compression-ignition (RCCI) engine using a combination of optical diagnostics and chemical kinetics modeling to explain the role of equivalence ratio, temperature, and fuel reactivity stratification for heat-release rate control. An optically accessible engine is operated in the RCCI combustion mode using gasoline primary reference fuels (PRF). A well-mixed charge of iso-octane (PRF = 100) is created by injecting fuel into the engine cylinder during the intake stroke using a gasoline-type direct injector. Later in the cycle, n-heptane (PRF = 0) is delivered through a centrally mounted diesel-type common-rail injector. This injection strategy generates stratification in equivalence ratio, fuel blend, and temperature. The first part of this study uses a high-speed camera to image the injection events and record high-temperature combustion chemiluminescence. Moreover, the chemiluminescence imaging showed that, at the operating condition studied in the present work, mixtures in the squish region ignite first, and the reaction zone proceeds inward toward the center of the combustion chamber. The second part of this study investigates the charge preparation of the RCCI strategy using planar laser-induced fluorescence (PLIF) of a fuel tracer under non-reacting conditions to quantify fuel concentration distributions prior to ignition. The fuel-tracer PLIF data show that the combustion event proceeds down gradients in the n-heptane distribution. The third part of the study uses chemical kinetics modeling over a range of mixtures spanning the distributions observed from the fuel-tracer fluorescence imaging to isolate the roles of temperature, equivalence ratio, and PRF number stratification. The simulations predict that PRF number stratification is the dominant factor controlling the ignition location and growth rate of the reaction zone. Equivalence ratio has a smaller, but still significant

  9. Geothermal Heat Pump Manufacturing Activities

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

    8 Geothermal heat pump shipments by origin, 2008 and 2009 (rated capacity in tons) Origin ... Administration (EIA), Form EIA-902, "Annual Geothermal Heat Pump Manufacturers Survey

  10. Geothermal Heat Pump Manufacturing Activities

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

    0 Geothermal heat pump domestic shipments by customer type, 2008 and 2009 (rated capacity ... Administration (EIA), Form EIA-902, "Annual Geothermal Heat Pump Manufacturers Survey

  11. Geothermal Heat Pump Manufacturing Activities

    Gasoline and Diesel Fuel Update (EIA)

    1 Geothermal heat pump domestic shipments by sector and model type, 2009 (rated capacity ... Administration (EIA), Form EIA-902, "Annual Geothermal Heat Pump Manufacturers Survey

  12. Geothermal Heat Pump Manufacturing Activities

    Gasoline and Diesel Fuel Update (EIA)

    Rated capacity of geothermal heat pump shipments by model type, 2000 - 2009 (tons) ARI-320 ... Administration (EIA), Form EIA-902, "Annual Geothermal Heat Pump Manufacturers Survey."

  13. 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.

  14. Approximate circuits for increased reliability

    DOE Patents [OSTI]

    Hamlet, Jason R.; Mayo, Jackson R.

    2015-08-18

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

  15. Approximate circuits for increased reliability

    DOE Patents [OSTI]

    Hamlet, Jason R.; Mayo, Jackson R.

    2015-12-22

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

  16. 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.

  17. Compare All CBECS Activities: District Heat Use

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

    District Heat Use Compare Activities by ... District Heat Use Total District Heat Consumption by Building Type Commercial buildings in the U.S. used a total of approximately 433...

  18. Evaluating temperature and fuel stratification for heat-release rate control in a reactivity-controlled compression-ignition engine using optical diagnostics and chemical kinetics modeling

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

    Musculus, Mark P. B.; Kokjohn, Sage L.; Reitz, Rolf D.

    2015-04-23

    We investigated the combustion process in a dual-fuel, reactivity-controlled compression-ignition (RCCI) engine using a combination of optical diagnostics and chemical kinetics modeling to explain the role of equivalence ratio, temperature, and fuel reactivity stratification for heat-release rate control. An optically accessible engine is operated in the RCCI combustion mode using gasoline primary reference fuels (PRF). A well-mixed charge of iso-octane (PRF = 100) is created by injecting fuel into the engine cylinder during the intake stroke using a gasoline-type direct injector. Later in the cycle, n-heptane (PRF = 0) is delivered through a centrally mounted diesel-type common-rail injector. This injectionmore » strategy generates stratification in equivalence ratio, fuel blend, and temperature. The first part of this study uses a high-speed camera to image the injection events and record high-temperature combustion chemiluminescence. Moreover, the chemiluminescence imaging showed that, at the operating condition studied in the present work, mixtures in the squish region ignite first, and the reaction zone proceeds inward toward the center of the combustion chamber. The second part of this study investigates the charge preparation of the RCCI strategy using planar laser-induced fluorescence (PLIF) of a fuel tracer under non-reacting conditions to quantify fuel concentration distributions prior to ignition. The fuel-tracer PLIF data show that the combustion event proceeds down gradients in the n-heptane distribution. The third part of the study uses chemical kinetics modeling over a range of mixtures spanning the distributions observed from the fuel-tracer fluorescence imaging to isolate the roles of temperature, equivalence ratio, and PRF number stratification. The simulations predict that PRF number stratification is the dominant factor controlling the ignition location and growth rate of the reaction zone. Equivalence ratio has a smaller, but still

  19. Explicit approximations to estimate the perturbative diffusivity in the presence of convectivity and damping. I. Semi-infinite slab approximations

    SciTech Connect (OSTI)

    Berkel, M. van; Zwart, H. J.; Tamura, N.; Ida, K.; Hogeweij, G. M. D.; Inagaki, S.; Baar, M. R. de

    2014-11-15

    In this paper, a number of new approximations are introduced to estimate the perturbative diffusivity (χ), convectivity (V), and damping (τ) in cylindrical geometry. For this purpose, the harmonic components of heat waves induced by localized deposition of modulated power are used. The approximations are based on semi-infinite slab approximations of the heat equation. The main result is the approximation of χ under the influence of V and τ based on the phase of two harmonics making the estimate less sensitive to calibration errors. To understand why the slab approximations can estimate χ well in cylindrical geometry, the relationships between heat transport models in slab and cylindrical geometry are studied. In addition, the relationship between amplitude and phase with respect to their derivatives, used to estimate χ, is discussed. The results are presented in terms of the relative error for the different derived approximations for different values of frequency, transport coefficients, and dimensionless radius. The approximations show a significant region in which χ, V, and τ can be estimated well, but also regions in which the error is large. Also, it is shown that some compensation is necessary to estimate V and τ in a cylindrical geometry. On the other hand, errors resulting from the simplified assumptions are also discussed showing that estimating realistic values for V and τ based on infinite domains will be difficult in practice. This paper is the first part (Part I) of a series of three papers. In Part II and Part III, cylindrical approximations based directly on semi-infinite cylindrical domain (outward propagating heat pulses) and inward propagating heat pulses in a cylindrical domain, respectively, will be treated.

  20. Miniature heat pumps for portable and distributed space conditioning applications

    SciTech Connect (OSTI)

    Drost, M.K.; Friedrich, M.

    1997-12-31

    The Pacific Northwest National Laboratory (PNNL) is developing a miniature absorption heat pump for a range of microclimate control applications, including manportable cooling and distributed space conditioning. The miniature absorption heat pump will be sized to provide 350 W cooling, will have dimensions of 9 cm x 9 cm x 6 cm, and will weigh approximately 0.65 kg. Compared to a macroscale absorption heat pump, this represents reduction in volume by a factor of 60. A complete manportable cooling system including the heat pump, an air-cooled heat exchanger, batteries, and fuel is estimated to weight between 4 and 5 kg, compared to the 10 kg weight of alternative systems. Size and weight reductions are obtained by developing a device that can simultaneously take advantage of the high heat and mass transfer rates attainable in microscale structures while being large enough to allow electric powered pumping.

  1. Approximate Model for Turbulent Stagnation Point Flow.

    SciTech Connect (OSTI)

    Dechant, Lawrence

    2016-01-01

    Here we derive an approximate turbulent self-similar model for a class of favorable pressure gradient wedge-like flows, focusing on the stagnation point limit. While the self-similar model provides a useful gross flow field estimate this approach must be combined with a near wall model is to determine skin friction and by Reynolds analogy the heat transfer coefficient. The combined approach is developed in detail for the stagnation point flow problem where turbulent skin friction and Nusselt number results are obtained. Comparison to the classical Van Driest (1958) result suggests overall reasonable agreement. Though the model is only valid near the stagnation region of cylinders and spheres it nonetheless provides a reasonable model for overall cylinder and sphere heat transfer. The enhancement effect of free stream turbulence upon the laminar flow is used to derive a similar expression which is valid for turbulent flow. Examination of free stream enhanced laminar flow suggests that the rather than enhancement of a laminar flow behavior free stream disturbance results in early transition to turbulent stagnation point behavior. Excellent agreement is shown between enhanced laminar flow and turbulent flow behavior for high levels, e.g. 5% of free stream turbulence. Finally the blunt body turbulent stagnation results are shown to provide realistic heat transfer results for turbulent jet impingement problems.

  2. 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.

  3. Explicit approximations to estimate the perturbative diffusivity in the presence of convectivity and damping. II. Semi-infinite cylindrical approximations

    SciTech Connect (OSTI)

    Berkel, M. van; Hogeweij, G. M. D.; Tamura, N.; Ida, K.; Zwart, H. J.; Inagaki, S.; Baar, M. R. de

    2014-11-15

    In this paper, a number of new explicit approximations are introduced to estimate the perturbative diffusivity (χ), convectivity (V), and damping (τ) in a cylindrical geometry. For this purpose, the harmonic components of heat waves induced by localized deposition of modulated power are used. The approximations are based upon the heat equation in a semi-infinite cylindrical domain. The approximations are based upon continued fractions, asymptotic expansions, and multiple harmonics. The relative error for the different derived approximations is presented for different values of frequency, transport coefficients, and dimensionless radius. Moreover, it is shown how combinations of different explicit formulas can yield good approximations over a wide parameter space for different cases, such as no convection and damping, only damping, and both convection and damping. This paper is the second part (Part II) of a series of three papers. In Part I, the semi-infinite slab approximations have been treated. In Part III, cylindrical approximations are treated for heat waves traveling towards the center of the plasma.

  4. Plasma Physics Approximations in Ares

    SciTech Connect (OSTI)

    Managan, R. A.

    2015-01-08

    Lee & More derived analytic forms for the transport properties of a plasma. Many hydro-codes use their formulae for electrical and thermal conductivity. The coefficients are complex functions of Fermi-Dirac integrals, Fn( μ/θ ), the chemical potential, μ or ζ = ln(1+e μ/θ ), and the temperature, θ = kT. Since these formulae are expensive to compute, rational function approximations were fit to them. Approximations are also used to find the chemical potential, either μ or ζ . The fits use ζ as the independent variable instead of μ/θ . New fits are provided for Aα (ζ ),Aβ (ζ ), ζ, f(ζ ) = (1 + e-μ/θ)F1/2(μ/θ), F1/2'/F1/2, Fcα, and Fcβ. In each case the relative error of the fit is minimized since the functions can vary by many orders of magnitude. The new fits are designed to exactly preserve the limiting values in the non-degenerate and highly degenerate limits or as ζ→ 0 or ∞. The original fits due to Lee & More and George Zimmerman are presented for comparison.

  5. 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.

  6. Geothermal District Heating Economics

    Energy Science and Technology Software Center (OSTI)

    1995-07-12

    GEOCITY is a large-scale simulation model which combines both engineering and economic submodels to systematically calculate the cost of geothermal district heating systems for space heating, hot-water heating, and process heating based upon hydrothermal geothermal resources. The GEOCITY program simulates the entire production, distribution, and waste disposal process for geothermal district heating systems, but does not include the cost of radiators, convectors, or other in-house heating systems. GEOCITY calculates the cost of district heating basedmore » on the climate, population, and heat demand of the district; characteristics of the geothermal resource and distance from the distribution center; well-drilling costs; design of the distribution system; tax rates; and financial conditions.« less

  7. Expert Meeting Report: Exploring the Disconnect Between Rated...

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

    Exploring the Disconnect Between Rated and Field Performance of Water Heating Systems M. ... Between Rated and Field Performance of Water Heating Systems Prepared for: The National ...

  8. 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.

  9. An approximation technique for jet impingement flow

    SciTech Connect (OSTI)

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

    2015-03-10

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

  10. Magnetic reconnection under anisotropic magnetohydrodynamic approximation

    SciTech Connect (OSTI)

    Hirabayashi, K.; Hoshino, M.

    2013-11-15

    We study the formation of slow-mode shocks in collisionless magnetic reconnection by using one- and two-dimensional collisionless MHD codes based on the double adiabatic approximation and the Landau closure model. We bridge the gap between the Petschek-type MHD reconnection model accompanied by a pair of slow shocks and the observational evidence of the rare occasion of in-situ slow shock observations. Our results showed that once magnetic reconnection takes place, a firehose-sense (p{sub ?}>p{sub ?}) pressure anisotropy arises in the downstream region, and the generated slow shocks are quite weak comparing with those in an isotropic MHD. In spite of the weakness of the shocks, however, the resultant reconnection rate is 10%30% higher than that in an isotropic case. This result implies that the slow shock does not necessarily play an important role in the energy conversion in the reconnection system and is consistent with the satellite observation in the Earth's magnetosphere.

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

    SciTech Connect (OSTI)

    Abdelaziz, Omar; Shrestha, Som S

    2014-01-01

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

  12. HEAT TRANSFER METHOD

    DOE Patents [OSTI]

    Gambill, W.R.; Greene, N.D.

    1960-08-30

    A method is given for increasing burn-out heat fluxes under nucleate boiling conditions in heat exchanger tubes without incurring an increase in pumping power requirements. This increase is achieved by utilizing a spinning flow having a rotational velocity sufficient to produce a centrifugal acceleration of at least 10,000 g at the tube wall. At this acceleration the heat-transfer rate at burn out is nearly twice the rate which can be achieved in a similar tube utilizing axial flow at the same pumping power. At higher accelerations the improvement over axial flow is greater, and heat fluxes in excess of 50 x 10/sup 6/ Btu/hr/sq ft can be achieved.

  13. The Broadband Heating Rate Profile (BBHRP) VAP

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

    National Laboratory Richland, Washington R. G. Ellingson Florida State University Tallahassee, Florida M. H. Zhang State University of New York at Albany Albany, New York Stony ...

  14. Property:HeatRate | Open Energy Information

    Open Energy Info (EERE)

    Landfi Biomass Facility + 12,916.67 + Atlantic County Util Biomass Facility + 13,648 + Avon Energy Partners LLC Biomass Facility + 10,366.7 + B BJ Gas Recovery Biomass Facility +...

  15. 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.

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

    SciTech Connect (OSTI)

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

    2009-08-31

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

  17. Rate Information

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

    links Financial Information Financial Public Processes Asset Management Cost Verification Process Rate Cases Rate Information Current Power Rates Current Transmission Rates...

  18. Approximate error conjugation gradient minimization methods

    DOE Patents [OSTI]

    Kallman, Jeffrey S

    2013-05-21

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

  19. 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...

  20. Total Space Heating Water Heating Cook-

    Gasoline and Diesel Fuel Update (EIA)

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

  1. Total Space Heating Water Heating Cook-

    Gasoline and Diesel Fuel Update (EIA)

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

  2. Total Space Heating Water Heating Cook-

    Gasoline and Diesel Fuel Update (EIA)

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

  3. Total Space Heating Water Heating Cook-

    Gasoline and Diesel Fuel Update (EIA)

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

  4. 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...

  5. Whistler turbulence heating of electrons and ions: Three-dimensional particle-in-cell simuations

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

    Gary, S. Peter; Hughes, R. Scott; Wang, Joseph

    2016-01-14

    In this study, the decay of whistler turbulence in a collisionless, homogeneous, magnetized plasma is studied using three-dimensional particle-in-cell simulations. The simulations are initialized with a narrowband, relatively isotropic distribution of long wavelength whistler modes. A first ensemble of simulations at electron betamore » $${\\beta }_{{\\rm{e}}}$$ = 0.25 and ion-to-electron mass ratio $${m}_{{\\rm{i}}}$$/$${m}_{{\\rm{e}}}$$ = 400 is carried out on a domain cube of dimension $$L{\\omega }_{\\mathrm{pi}}$$/c = 5.12 where $${\\omega }_{\\mathrm{pi}}$$ is the ion plasma frequency. The simulations begin with a range of dimensionless fluctuating field energy densities, $${\\epsilon }_{{\\rm{o}}}$$, and follow the fluctuations as they cascade to broadband, anisotropic turbulence which dissipates at shorter wavelengths, heating both electrons and ions. The electron heating is stronger and preferentially parallel/antiparallel to the background magnetic field $${{\\boldsymbol{B}}}_{{\\rm{o}}};$$ the ion energy gain is weaker and is preferentially in directions perpendicular to $${{\\boldsymbol{B}}}_{{\\rm{o}}}$$. The important new results here are that, over 0.01 < $${\\epsilon }_{{\\rm{o}}}$$ < 0.25, the maximum rate of electron heating scales approximately as $${\\epsilon }_{{\\rm{o}}}$$, and the maximum rate of ion heating scales approximately as $${\\epsilon }_{{\\rm{o}}}^{1.5}$$. A second ensemble of simulations at $${\\epsilon }_{{\\rm{o}}}$$ = 0.10 and $${\\beta }_{{\\rm{e}}}$$ = 0.25 shows that, over 25 < $${m}_{{\\rm{i}}}$$/$${m}_{{\\rm{e}}}\\;$$< 1836, the ratio of the maximum ion heating rate to the maximum electron heating rate scales approximately as $${m}_{{\\rm{e}}}$$/$${m}_{{\\rm{i}}}$$.« less

  6. A Survey of Techniques for Approximate Computing

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

    Mittal, Sparsh

    2016-03-18

    Approximate computing trades off computation quality with the effort expended and as rising performance demands confront with plateauing resource budgets, approximate computing has become, not merely attractive, but even imperative. Here, we present a survey of techniques for approximate computing (AC). We discuss strategies for finding approximable program portions and monitoring output quality, techniques for using AC in different processing units (e.g., CPU, GPU and FPGA), processor components, memory technologies etc., and programming frameworks for AC. Moreover, we classify these techniques based on several key characteristics to emphasize their similarities and differences. Finally, the aim of this paper is tomore » provide insights to researchers into working of AC techniques and inspire more efforts in this area to make AC the mainstream computing approach in future systems.« less

  7. Drag reducing effects of polymer additives in a plate heat exchanger for the OTEC system

    SciTech Connect (OSTI)

    Kim, N.; Yoon, S.; Kim, C.; Seo, T.

    1999-07-01

    Experiments were undertaken for a 15kW Alfa-Laval plate heat exchanger utilizing polyethylene oxide as a polymer additive. Concentrations of polymer additives were 5, 10, 20, 30, 40, 50, 100, 200 and 400 wppm at 25 C and mass flow rates were 0.6kg/s, 0.7kg/s, 0.8kg/s and 0.9kg/s in normal operating ranges of the plate heat exchanger. The maximum effects of drag reductions were found at 20 wppm polymer concentration and at approximately 0.7kg/s of mass flow rate. The results show that there exist optimum polymer concentration and at approximately 0.7kg/s of mass flow rate. The results show that there exist optimum polymer concentration and mass flow rate for the plate heat exchanger for maximum drag reduction effects. In most cases, drag reduction of approximately 20% has been obtained. It means considerable savings in pumping power for a large size OTEC plant.

  8. An improved proximity force approximation for electrostatics

    SciTech Connect (OSTI)

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

    2012-08-15

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

  9. Geothermal Heat Pump Manufacturing Activities

    Gasoline and Diesel Fuel Update (EIA)

    ARI-320 ARI-325330 ARI-870 Other Non-ARI Rated 2008 13.1 19.5 17.5 13.5 2009 14.6 20.4 18.2 14.3 ARI-320 Water-Source Heat Pumps. ARI-325 Ground Water-Source Heat Pumps. ...

  10. Geothermal Heat Pump Manufacturing Activities

    Gasoline and Diesel Fuel Update (EIA)

    ARI-320 ARI-325330 ARI-870 Other Non-ARI Rated 2008 4.4 4.0 4.2 3.6 2009 3.9 4.1 4.3 3.8 ARI-320 Water-Source Heat Pumps. ARI-325 Ground Water-Source Heat Pumps. ARI-330 ...

  11. Heat collector

    DOE Patents [OSTI]

    Merrigan, M.A.

    1981-06-29

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

  12. Heat collector

    DOE Patents [OSTI]

    Merrigan, Michael A.

    1984-01-01

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

  13. Approximations of very weak solutions to boundary-value problems.

    SciTech Connect (OSTI)

    Berggren, Martin Olof

    2003-03-01

    Standard weak solutions to the Poisson problem on a bounded domain have square-integrable derivatives, which limits the admissible regularity of inhomogeneous data. The concept of solution may be further weakened in order to define solutions when data is rough, such as for inhomogeneous Dirichlet data that is only square-integrable over the boundary. Such very weak solutions satisfy a nonstandard variational form (u, v) = G(v). A Galerkin approximation combined with an approximation of the right-hand side G defines a finite-element approximation of the very weak solution. Applying conforming linear elements leads to a discrete solution equivalent to the text-book finite-element solution to the Poisson problem in which the boundary data is approximated by L{sub 2}-projections. The L{sub 2} convergence rate of the discrete solution is O(h{sub s}) for some s {element_of} (0,1/2) that depends on the shape of the domain, asserting a polygonal (two-dimensional) or polyhedral (three-dimensional) domain without slits and (only) square-integrable boundary data.

  14. Low-order modeling of internal heat transfer in biomass particle pyrolysis

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

    Wiggins, Gavin M.; Daw, C. Stuart; Ciesielski, Peter N.

    2016-05-11

    We present a computationally efficient, one-dimensional simulation methodology for biomass particle heating under conditions typical of fast pyrolysis. Our methodology is based on identifying the rate limiting geometric and structural factors for conductive heat transport in biomass particle models with realistic morphology to develop low-order approximations that behave appropriately. Comparisons of transient temperature trends predicted by our one-dimensional method with three-dimensional simulations of woody biomass particles reveal good agreement, if the appropriate equivalent spherical diameter and bulk thermal properties are used. Here, we conclude that, for particle sizes and heating regimes typical of fast pyrolysis, it is possible to simulatemore » biomass particle heating with reasonable accuracy and minimal computational overhead, even when variable size, aspherical shape, anisotropic conductivity, and complex, species-specific internal pore geometry are incorporated.« less

  15. 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)

  16. Acoustically enhanced heat exchange and drying apparatus

    DOE Patents [OSTI]

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

    1987-07-10

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

  17. 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.

  18. Thermal effects and sudden decay approximation in the curvaton scenario

    SciTech Connect (OSTI)

    Kitajima, Naoya; Takesako, Tomohiro; Yokoyama, Shuichiro; Langlois, David; Takahashi, Tomo E-mail: langlois@apc.univ-paris7.fr E-mail: takesako@icrr.u-tokyo.ac.jp

    2014-10-01

    We study the impact of a temperature-dependent curvaton decay rate on the primordial curvature perturbation generated in the curvaton scenario. Using the familiar sudden decay approximation, we obtain an analytical expression for the curvature perturbation after the decay of the curvaton. We then investigate numerically the evolution of the background and of the perturbations during the decay. We first show that the instantaneous transfer coefficient, related to the curvaton energy fraction at the decay, can be extended into a more general parameter, which depends on the net transfer of the curvaton energy into radiation energy or, equivalently, on the total entropy ratio after the complete curvaton decay. We then compute the curvature perturbation and compare this result with the sudden decay approximation prediction.

  19. Cooperative heat transfer and ground coupled storage system

    DOE Patents [OSTI]

    Metz, P.D.

    A cooperative heat transfer and ground coupled storage system wherein collected solar heat energy is ground stored and permitted to radiate into the adjacent ground for storage therein over an extended period of time when such heat energy is seasonally maximally available. Thereafter, when said heat energy is seasonally minimally available and has propagated through the adjacent ground a substantial distance, the stored heat energy may be retrieved by a circumferentially arranged heat transfer means having a high rate of heat transfer.

  20. Cooperative heat transfer and ground coupled storage system

    DOE Patents [OSTI]

    Metz, Philip D.

    1982-01-01

    A cooperative heat transfer and ground coupled storage system wherein collected solar heat energy is ground stored and permitted to radiate into the adjacent ground for storage therein over an extended period of time when such heat energy is seasonally maximally available. Thereafter, when said heat energy is seasonally minimally available and has propagated through the adjacent ground a substantial distance, the stored heat energy may be retrieved by a circumferentially arranged heat transfer means having a high rate of heat transfer.

  1. Second derivatives for approximate spin projection methods

    SciTech Connect (OSTI)

    Thompson, Lee M.; Hratchian, Hrant P.

    2015-02-07

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

  2. Rate Schedules

    Broader source: Energy.gov [DOE]

    One of the major responsibilities of Southeastern is to design, formulate, and justify rate schedules. Repayment studies prepared by the agency determine revenue requirements and appropriate rate...

  3. 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...

  4. 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.

  5. 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)...

  6. Relativistic Random Phase Approximation At Finite Temperature

    SciTech Connect (OSTI)

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

    2009-08-26

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

  7. Waste Heat to Power Market Assessment

    SciTech Connect (OSTI)

    Elson, Amelia; Tidball, Rick; Hampson, Anne

    2015-03-01

    Waste heat to power (WHP) is the process of capturing heat discarded by an existing process and using that heat to generate electricity. In the industrial sector, waste heat streams are generated by kilns, furnaces, ovens, turbines, engines, and other equipment. In addition to processes at industrial plants, waste heat streams suitable for WHP are generated at field locations, including landfills, compressor stations, and mining sites. Waste heat streams are also produced in the residential and commercial sectors, but compared to industrial sites these waste heat streams typically have lower temperatures and much lower volumetric flow rates. The economic feasibility for WHP declines as the temperature and flow rate decline, and most WHP technologies are therefore applied in industrial markets where waste heat stream characteristics are more favorable. This report provides an assessment of the potential market for WHP in the industrial sector in the United States.

  8. Rate of reduction of ore-carbon composites: Part II. Modeling of reduction in extended composites

    SciTech Connect (OSTI)

    Fortini, O.M.; Fruehan, R.J.

    2005-12-01

    A new process for ironmaking was proposed using a rotary hearth furnace and an iron bath smelter to produce iron employing wood charcoal as an energy source and reductant. This paper examines reactions in composite pellet samples with sizes close to sizes used in industrial practice (10 to 16 min in diameter). A model was constructed using the combined kinetic mechanism developed in Part I of this series of articles along with equations for the computation of pellet temperature and shrinkage during the reaction. The analysis of reaction rates measured for pellets with wood charcoal showed that heat transfer plays a significant role in their overall rate of reaction at elevated temperatures. The slower rates measured in pellets containing coal char show that the intrinsic kinetics of carbon oxidation is more significant than heat transfer. Model calculations suggest that the rates are highly sensitive to the thermal conductivity of pellets containing wood charcoal and are less sensitive to the external conditions of heat transfer. It was seen that the changes in pellet surface area and diameter due to shrinkage introduce little change on reaction rates. The model developed provides an adequate description of pellets of wood charcoal up to circa 90% of reduction. Experimentally determined rates of reduction of iron oxide by wood charcoal were approximately 5 to 10 times faster than rates measured in pellets with coal char.

  9. 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.

  10. Heat exchanger for power generation equipment

    DOE Patents [OSTI]

    Nirmalan, Nirm Velumylm; Bowman, Michael John

    2005-06-14

    A heat exchanger for a turbine is provided wherein the heat exchanger comprises a heat transfer cell comprising a sheet of material having two opposed ends and two opposed sides. In addition, a plurality of concavities are disposed on a surface portion of the sheet of material so as to cause hydrodynamic interactions and affect a heat transfer rate of the turbine between a fluid and the concavities when the fluid is disposed over the concavities.

  11. Comparison of Methods for Calculating Radiative Heat Transfer

    SciTech Connect (OSTI)

    Schock, Alfred; Abbate, M J

    2012-01-19

    Various approximations for calculating radioactive heat transfer between parallel surfaces are evaluated. This is done by applying the approximations based on total emissivities to a special case of known spectral emissivities, for which exact heat transfer calculations are possible. Comparison of results indicates that the best approximation is obtained by basing the emissivity of the receiving surface primarily on the temperature of the emitter. A specific model is shown to give excellent agreement over a very wide range of values.

  12. Semiclassical approximation to supersymmetric quantum gravity

    SciTech Connect (OSTI)

    Kiefer, Claus; Lueck, Tobias; Moniz, Paulo

    2005-08-15

    We develop a semiclassical approximation scheme for the constraint equations of supersymmetric canonical quantum gravity. This is achieved by a Born-Oppenheimer type of expansion, in analogy to the case of the usual Wheeler-DeWitt equation. The formalism is only consistent if the states at each order depend on the gravitino field. We recover at consecutive orders the Hamilton-Jacobi equation, the functional Schroedinger equation, and quantum gravitational correction terms to this Schroedinger equation. In particular, the following consequences are found: (i) the Hamilton-Jacobi equation and therefore the background spacetime must involve the gravitino, (ii) a (many-fingered) local time parameter has to be present on super Riem {sigma} (the space of all possible tetrad and gravitino fields) (iii) quantum supersymmetric gravitational corrections affect the evolution of the very early Universe. The physical meaning of these equations and results, in particular, the similarities to and differences from the pure bosonic case, are discussed.

  13. Heat exchanger containing a component capable of discontinuous movement

    DOE Patents [OSTI]

    Wilson, David Gordon

    2001-04-17

    Regenerative heat exchangers are described for transferring heat between hot and cold fluids. The heat exchangers have seal-leakage rates significantly less than those of conventional regenerative heat exchangers because the matrix is discontinuously moved and is releasably sealed while in a stationary position. Both rotary and modular heat exchangers are described. Also described are methods for transferring heat between a hot and cold fluid using the discontinuous movement of matrices.

  14. Heat exchanger containing a component capable of discontinuous movement

    DOE Patents [OSTI]

    Wilson, D.G.

    1993-11-09

    Regenerative heat exchangers are described for transferring heat between hot and cold fluids. The heat exchangers have seal-leakage rates significantly less than those of conventional regenerative heat exchangers because the matrix is discontinuously moved and is releasably sealed while in a stationary position. Both rotary and modular heat exchangers are described. Also described are methods for transferring heat between a hot and cold fluid using the discontinuous movement of matrices. 11 figures.

  15. Heat exchanger containing a component capable of discontinuous movement

    DOE Patents [OSTI]

    Wilson, David G.

    1993-01-01

    Regenerative heat exchangers are described for transferring heat between hot and cold fluids. The heat exchangers have seal-leakage rates significantly less than those of conventional regenerative heat exchangers because the matrix is discontinuously moved and is releasably sealed while in a stationary position. Both rotary and modular heat exchangers are described. Also described are methods for transferring heat between a hot and cold fluid using the discontinuous movement of matrices.

  16. Heat exchanger containing a component capable of discontinuous movement

    DOE Patents [OSTI]

    Wilson, David Gordon

    2002-01-01

    Regenerative heat exchangers are described for transferring heat between hot and cold fluids. The heat exchangers have seal-leakage rates significantly less than those of conventional regenerative heat exchangers because the matrix is discontinuously moved and is releasably sealed while in a stationary position. Both rotary and modular heat exchangers are described. Also described are methods for transferring heat between a hot and cold fluid using the discontinuous movement of matrices.

  17. 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.

  18. 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.

  19. Finance & Rates

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

    all of its costs in the rates it charges customers for wholesale electricity and transmission services. The agency is committed to careful cost management consistent with its...

  20. Examination of frit vent from Sixty-Watt Heat Source simulant fueled clad vent set

    SciTech Connect (OSTI)

    Ulrich, G.B.

    1995-11-01

    The flow rate and the metallurgical condition of a frit vent from a simulant-fueled clad vent set (CVS) that had been hot isostatically pressed (HIP) for the Sixty-Watt Heat Source program were evaluated. The flow rate form the defueled vent cup subassembly was reduced approximately 25% from the original flow rate. No obstructions were found to account for the reduced flow rate. Measurements indicate that the frit vent powder thickness was reduced about 30%. Most likely, the powder was compressed during the HIP operation, which increased the density of the powder layer and thus reduced the flow rate of the assembly. All other observed manufacturing attributes appeared to be normal, but the vent hole activation technique needs further refinement before it is used in applications requiring maximum CVS integrity.

  1. Molecular Solid EOS based on Quasi-Harmonic Oscillator approximation for phonons

    SciTech Connect (OSTI)

    Menikoff, Ralph

    2014-09-02

    A complete equation of state (EOS) for a molecular solid is derived utilizing a Helmholtz free energy. Assuming that the solid is nonconducting, phonon excitations dominate the specific heat. Phonons are approximated as independent quasi-harmonic oscillators with vibrational frequencies depending on the specific volume. The model is suitable for calibrating an EOS based on isothermal compression data and infrared/Raman spectroscopy data from high pressure measurements utilizing a diamond anvil cell. In contrast to a Mie-Gr ̈uneisen EOS developed for an atomic solid, the specific heat and Gr ̈uneisen coefficient depend on both density and temperature.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Bond selective chemistry beyond the adiabatic approximation

    SciTech Connect (OSTI)

    Butler, L.J.

    1993-12-01

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

  8. OBSERVATIONAL TEST OF STOCHASTIC HEATING IN LOW-{beta} FAST-SOLAR-WIND STREAMS

    SciTech Connect (OSTI)

    Bourouaine, Sofiane; Chandran, Benjamin D. G.

    2013-09-10

    Spacecraft measurements show that protons undergo substantial perpendicular heating during their transit from the Sun to the outer heliosphere. In this paper, we use Helios 2 measurements to investigate whether stochastic heating by low-frequency turbulence is capable of explaining this perpendicular heating. We analyze Helios 2 magnetic field measurements in low-{beta} fast-solar-wind streams between heliocentric distances r = 0.29 AU and r = 0.64 AU to determine the rms amplitude of the fluctuating magnetic field, {delta}B{sub p}, near the proton gyroradius scale {rho}{sub p}. We then evaluate the stochastic heating rate Q{sub stoch} using the measured value of {delta}B{sub p} and a previously published analytical formula for Q{sub stoch}. Using Helios measurements we estimate the ''empirical'' perpendicular heating rate Q{sub Up-Tack emp} = (k{sub B}/m{sub p}) BV (d/dr) (T{sub Up-Tack p}/B) that is needed to explain the T{sub p} profile. We find that Q{sub stoch} {approx} Q{sub emp}, but only if a key dimensionless constant appearing in the formula for Q{sub stoch} lies within a certain range of values. This range is approximately the same throughout the radial interval that we analyze and is consistent with the results of numerical simulations of the stochastic heating of test particles in reduced magnetohydrodynamic turbulence. These results support the hypothesis that stochastic heating accounts for much of the perpendicular proton heating occurring in low-{beta} fast-wind streams.

  9. 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.

  10. Climate, extreme heat, and electricity demand in California

    SciTech Connect (OSTI)

    Miller, N.L.; Hayhoe, K.; Jin, J.; Auffhammer, M.

    2008-04-01

    Climate projections from three atmosphere-ocean climate models with a range of low to mid-high temperature sensitivity forced by the Intergovernmental Panel for Climate Change SRES higher, middle, and lower emission scenarios indicate that, over the 21st century, extreme heat events for major cities in heavily air-conditioned California will increase rapidly. These increases in temperature extremes are projected to exceed the rate of increase in mean temperature, along with increased variance. Extreme heat is defined here as the 90 percent exceedance probability (T90) of the local warmest summer days under the current climate. The number of extreme heat days in Los Angeles, where T90 is currently 95 F (32 C), may increase from 12 days to as many as 96 days per year by 2100, implying current-day heat wave conditions may last for the entire summer, with earlier onset. Overall, projected increases in extreme heat under the higher A1fi emission scenario by 2070-2099 tend to be 20-30 percent higher than those projected under the lower B1 emission scenario, ranging from approximately double the historical number of days for inland California cities (e.g. Sacramento and Fresno), up to four times for previously temperate coastal cities (e.g. Los Angeles, San Diego). These findings, combined with observed relationships between high temperature and electricity demand for air-conditioned regions, suggest potential shortfalls in transmission and supply during T90 peak electricity demand periods. When the projected extreme heat and peak demand for electricity are mapped onto current availability, maintaining technology and population constant only for demand side calculations, we find the potential for electricity deficits as high as 17 percent. Similar increases in extreme heat days are suggested for other locations across the U.S. southwest, as well as for developing nations with rapidly increasing electricity demands. Electricity response to recent extreme heat events, such

  11. 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.

  12. 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.

  13. Particle-number conservation in static-path approximation for thermal superfluid systems

    SciTech Connect (OSTI)

    Kaneko, K.; Schiller, A.

    2007-12-15

    By applying particle-number projection to the static-path approximation (SPA), the heat capacity and the breakdown of pairing correlations are investigated in the thermally excited, superfluid systems {sup 172}Yb, {sup 94}Mo, and {sup 56}Fe. For the heavy nucleus {sup 172}Yb, the heat capacities in both the SPA and the number-projected SPA (NPSPA) exhibit an S shape; the difference between the SPA and NPSPA heat-capacity curves is not very large and the particle-number projection thereby enhances the S shape already seen in the SPA. The temperature at which the S-shape of heat capacity curve occurs parallels the temperature of the breakdown of pairing correlations as indicated by the effective pairing gap. However, for the comparatively lighter nuclei {sup 94}Mo and {sup 56}Fe, the SPA does not produce an S-shaped heat capacity on its own; only after particle-number projection the S shape appears in the heat-capacity curve. For {sup 94}Mo, we compare the NPSPA result with thermal odd-even mass differences, which are regarded as a direct measure of the pairing gap.

  14. Approximate simulation of CO[sub 2] and H[sub 2]S absorption into aqueous alkanolamines

    SciTech Connect (OSTI)

    Glasscock, D.A.; Rochelle, G.T. . Dept. of Chemical Engineering)

    1993-08-01

    Rigorous and approximate methods are compared for the simulation of CO[sub 2] absorption into aqueous alkanolamine mixtures of methyldiethanolamine and diethanolamine. In addition, data for the mixtures containing monoethanolamine and the simultaneous absorption of CO[sub 2] and H[sub 2]S are presented. For the rigorous approach, the simplified eddy diffusivity theory is used to simulate the liquid-phase hydrodynamic characteristics. The approximation methods examined are the pseudo-first-order approximation, the interpolation approximation of Wellek et al. (1978), the algebraic combined flux (ACFLUX) approximation and the modified combined flux (MCFLUX) approximation. The latter approximation utilizes the reaction zone concept to determine the kinetic preference of the absorbing gas at the gas-liquid interface. Under the range of conditions studied, the MCFLUX approximation predicts very accurately the CO[sub 2] and H[sub 2]S flux rates in mixed amine systems, as compared with the rigorous solution of the differential equations.

  15. Radiative Heating in Underexplored Bands Campaign (RHUBC)

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

    Bands Campaign (RHUBC) D. Turner and E. Mlawer RHUBC Breakout Session 2008 ARM Science Team Meeting 13 March, 2008 Norfolk, Virginia Motivation * Radiative heating/cooling in the mid-troposphere modulate the vertical motions of the atmosphere - This heating/cooling occurs primarily in water vapor absorption bands that are opaque at the surface * Approximately 40% of the OLR comes from the far-IR * Until recently, the observational tools were not available to evaluate the accuracy of the far-IR

  16. DOE to Sell 35,000 Barrels of Oil from the Northeast Home Heating Oil Reserve

    Broader source: Energy.gov [DOE]

    WASHINGTON, DC - The U.S. Department of Energy announced today that it will sell approximately 35,000 barrels of home heating oil from the Northeast Home Heating Oil Reserve (NEHHOR).  The Reserve...

  17. Comparison of Alternatives to the 2004 Vacuum Vessel Heat Transfer...

    Office of Scientific and Technical Information (OSTI)

    as well as including a small safety-rated pump and HX in parallel to the main circulation pump and HX. The Vacuum Vessel (VV) Primary Heat Transfer System (PHTS) removes heat...

  18. Multiple source heat pump

    DOE Patents [OSTI]

    Ecker, Amir L.

    1983-01-01

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

  19. Heat release analysis of engine pressure data

    SciTech Connect (OSTI)

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

    1984-01-01

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

  20. Heating 7. 2 user's manual

    SciTech Connect (OSTI)

    Childs, K.W.

    1993-02-01

    HEATING is a general-purpose conduction heat transfer program written in Fortran 77. HEATING can solve steady-state and/or transient heat conduction problems in one-, two-, or three-dimensional Cartesian, cylindrical, or spherical coordinates. A model may include multiple materials, and the thermal conductivity, density, and specific heat of each material may be both time- and temperature-dependent. The thermal conductivity may also be anisotropic. Materials may undergo change of phase. Thermal properties of materials may be input or may be extracted from a material properties library. Heat-generation rates may be dependent on time, temperature, and position, and boundary temperatures may be time- and position-dependent. The boundary conditions, which may be surface-to-environment or surface-to-surface, may be specified temperatures or any combination of prescribed heat flux, forced convection, natural convection, and radiation. The boundary condition parameters may be time- and/or temperature-dependent. General gray-body radiation problems may be modeled with user-defined factors for radiant exchange. The mesh spacing may be variable along each axis. HEATING uses a runtime memory allocation scheme to avoid having to recompile to match memory requirements for each specific problem. HEATING utilizes free-form input. Three steady-state solution techniques are available: point-successive-overrelaxation iterative method with extrapolation, direct-solution, and conjugate gradient. Transient problems may be solved using any one of several finite-difference schemes: Crank-Nicolson implicit, Classical Implicit Procedure (CIP), Classical Explicit Procedure (CEP), or Levy explicit method. The solution of the system of equations arising from the implicit techniques is accomplished by point-successive-overrelaxation iteration and includes procedures to estimate the optimum acceleration parameter.

  1. Solar heating panel

    SciTech Connect (OSTI)

    Ellsworth, R.L.

    1983-01-18

    A solar heating panel for collecting solar heat energy and method for making same having a heat insulative substrate with a multiplicity of grooves and structural supporting ribs formed therein covered by a thin, flexible heat conductive film to form fluid conducting channels which in turn are connected to manifolds from which fluid is directed into the channels and heated fluid is removed therefrom.

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

    Energy Savers [EERE]

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

  3. Multifamily Individual Heating and Ventilation Systems, Lawrence...

    Energy Savers [EERE]

    than the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) 62.2 rate; an extensive system of ductwork, smoke and fre dampers, and duct chases ...

  4. Absorption heat pump system

    DOE Patents [OSTI]

    Grossman, G.

    1982-06-16

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

  5. Absorption heat pump system

    DOE Patents [OSTI]

    Grossman, Gershon

    1984-01-01

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

  6. Concentrating solar heat collector

    SciTech Connect (OSTI)

    Fattor, A.P.

    1980-09-23

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

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

    Open Energy Info (EERE)

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

  8. Philip District Heating District Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

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

  9. Kethcum District Heating District Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

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

  10. Midland District Heating District Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

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

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

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

    Northeast Home Heating Oil Reserve System (Heating Oil) PIA - Northeast Home Heating Oil Reserve System (Heating Oil) (3.31 MB) More Documents & Publications PIA - WEB Physical ...

  12. Convergence properties of polynomial chaos approximations for L2 random variables.

    SciTech Connect (OSTI)

    Field, Richard V., Jr. (.,; .); Grigoriu, Mircea (Cornell University, Ithaca, NY)

    2007-03-01

    Polynomial chaos (PC) representations for non-Gaussian random variables are infinite series of Hermite polynomials of standard Gaussian random variables with deterministic coefficients. For calculations, the PC representations are truncated, creating what are herein referred to as PC approximations. We study some convergence properties of PC approximations for L{sub 2} random variables. The well-known property of mean-square convergence is reviewed. Mathematical proof is then provided to show that higher-order moments (i.e., greater than two) of PC approximations may or may not converge as the number of terms retained in the series, denoted by n, grows large. In particular, it is shown that the third absolute moment of the PC approximation for a lognormal random variable does converge, while moments of order four and higher of PC approximations for uniform random variables do not converge. It has been previously demonstrated through numerical study that this lack of convergence in the higher-order moments can have a profound effect on the rate of convergence of the tails of the distribution of the PC approximation. As a result, reliability estimates based on PC approximations can exhibit large errors, even when n is large. The purpose of this report is not to criticize the use of polynomial chaos for probabilistic analysis but, rather, to motivate the need for further study of the efficacy of the method.

  13. Woven heat exchanger

    DOE Patents [OSTI]

    Piscitella, R.R.

    1984-07-16

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

  14. Total Space Heat-

    Gasoline and Diesel Fuel Update (EIA)

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

  15. Total Space Heat-

    Gasoline and Diesel Fuel Update (EIA)

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

  16. Total Space Heat-

    Gasoline and Diesel Fuel Update (EIA)

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

  17. Waste Heat Recovery

    Office of Environmental Management (EM)

    - PRE-DECISIONAL - DRAFT 1 Waste Heat Recovery 1 Technology Assessment 2 Contents 3 1. ... 2 4 1.1. Introduction to Waste Heat Recovery ......

  18. DOE Announces Award of a Contract to Repurchase Heating Oil for the

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

    Northeast Home Heating Oil Reserve | Department of Energy Award of a Contract to Repurchase Heating Oil for the Northeast Home Heating Oil Reserve DOE Announces Award of a Contract to Repurchase Heating Oil for the Northeast Home Heating Oil Reserve July 23, 2008 - 2:15pm Addthis WASHINGTON, DC - The U.S. Department of Energy today announced the award of a contract to Hess Corporation for the delivery of approximately 808,625 gallons (approximately 19,250 barrels) of home heating oil for the

  19. Rates Meetings and Workshops (pbl/rates)

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

    Rate Case Workshops Other Power Rates-Related Workshops July 1, 2004 - Rates and Finances Workshop (updated June 25, 2004) (financial and rate forecasts and scenarios for FY...

  20. Guide to Geothermal Heat Pumps

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

    among the most effcient and comfortable heating and cooling technologies available because they use the earth's natural heat to provide heating, cooling, and often, water heating. ...

  1. Helically coiled tube heat exchanger

    SciTech Connect (OSTI)

    Harris, A.M.

    1981-08-18

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

  2. Increasing Confidence In Geothermal Heat Pump Design Methods...

    Office of Scientific and Technical Information (OSTI)

    ... rate in the ground heat exchangers, allowed us to determine the thermal properties of the soil formation being experienced by the operating GHP system. Outputs from the models ...

  3. Grid-Interactive Renewable Water Heating Economic and Environmental...

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

    1 Grid-Interactive Renewable Water Heating Economic and Environmental Value Grid-interactive renewable water heaters have smart controls that quickly change their charge rate and ...

  4. Energy and IAQ Implications of Alternative Minimum Ventilation Rates in California Retail and School Buildings

    SciTech Connect (OSTI)

    Dutton, Spencer M.; Fisk, William J.

    2015-01-01

    For a stand-alone retail building, a primary school, and a secondary school in each of the 16 California climate zones, the EnergyPlus building energy simulation model was used to estimate how minimum mechanical ventilation rates (VRs) affect energy use and indoor air concentrations of an indoor-generated contaminant. The modeling indicates large changes in heating energy use, but only moderate changes in total building energy use, as minimum VRs in the retail building are changed. For example, predicted state-wide heating energy consumption in the retail building decreases by more than 50% and total building energy consumption decreases by approximately 10% as the minimum VR decreases from the Title 24 requirement to no mechanical ventilation. The primary and secondary schools have notably higher internal heat gains than in the retail building models, resulting in significantly reduced demand for heating. The school heating energy use was correspondingly less sensitive to changes in the minimum VR. The modeling indicates that minimum VRs influence HVAC energy and total energy use in schools by only a few percent. For both the retail building and the school buildings, minimum VRs substantially affected the predicted annual-average indoor concentrations of an indoor generated contaminant, with larger effects in schools. The shape of the curves relating contaminant concentrations with VRs illustrate the importance of avoiding particularly low VRs.

  5. Cab Heating and Cooling

    SciTech Connect (OSTI)

    Damman, Dennis

    2005-10-31

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

  6. Rotary magnetic heat pump

    DOE Patents [OSTI]

    Kirol, L.D.

    1987-02-11

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

  7. Rotary magnetic heat pump

    DOE Patents [OSTI]

    Kirol, Lance D.

    1988-01-01

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

  8. Direct fired heat exchanger

    DOE Patents [OSTI]

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

    1986-01-01

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

  9. Woven heat exchanger

    DOE Patents [OSTI]

    Piscitella, Roger R.

    1987-01-01

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

  10. Woven heat exchanger

    DOE Patents [OSTI]

    Piscitella, Roger R.

    1987-05-05

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

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

    Office of Scientific and Technical Information (OSTI)

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

  12. Charge-conjugation symmetric complete impulse approximation for...

    Office of Scientific and Technical Information (OSTI)

    from the spectator quark (referred to as the relativistic impulse approximation). In this study we also include the contributions from the poles of the quark which interacts with ...

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

    SciTech Connect (OSTI)

    Ledoux, Veerle; Van Daele, Marnix

    2010-09-30

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

  14. A Multithreaded Algorithm for Network Alignment Via Approximate...

    Office of Scientific and Technical Information (OSTI)

    The best current approaches are entirely heuristic, and are iterative in nature. They generate real-valued heuristic approximations that must be rounded to find integer solutions. ...

  15. Quasiparticle random-phase approximation with interactions from...

    Office of Scientific and Technical Information (OSTI)

    Quasiparticle random-phase approximation with interactions from the Similarity Renormalization Group Citation Details In-Document Search Title: Quasiparticle random-phase ...

  16. Evaporative heat transfer in beds of sensible heat pellets

    SciTech Connect (OSTI)

    Arimilli, R.V.; Moy, C.A.

    1989-03-01

    An experimental study of boiling/evaporative heat transfer from heated spheres in vertical packed beds with downward liquid-vapor flow of Refrigerant-113 was conducted. Surface superheats of 1 to 50{degrees}C, mass flow rates of 1.7 to 5.6 Kg/min, sphere diameters of 1.59 and 2.54 cm, quality (i.e., mass fraction of vapor) of the inlet flow of 0.02 to 1.0, and two surface conditions were considered. Instrumented smooth and rough aluminum spheres were used to measure the heat transfer coefficients under steady state conditions. Heat transfer coefficients were independently determined for each sphere at three values three values of surface superheat. The quantitative results of this extensive experimental study are successfully correlated. The correlation equation for the boiling heat transfer coefficients is presented in terms of a homogeneous model. The correlation may be used in the development of numerical models to simulate the transient thermal performance of packed bed thermal energy storage unit while operating as an evaporator. The boiling of the liquid-vapor flow around the spheres in the packed bed was visually observed with a fiber-optic baroscope and recorded on a videotape. The visualization results showed qualitatively the presence of four distinct flow regimes. One of these occurs under saturated inlet conditions and are referred to as the Low-quality, Medium-quality, and High-quality Regimes. The regimes are discussed in detail in this paper.

  17. Thulium-170 heat source

    DOE Patents [OSTI]

    Walter, Carl E.; Van Konynenburg, Richard; VanSant, James H.

    1992-01-01

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

  18. Heat Treating Apparatus

    DOE Patents [OSTI]

    De Saro, Robert; Bateman, Willis

    2002-09-10

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

  19. Thermoelectric heat exchange element

    DOE Patents [OSTI]

    Callas, James J.; Taher, Mahmoud A.

    2007-08-14

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

  20. Waste Heat Management Options for Improving Industrial Process Heating

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

    Systems | Department of Energy Waste Heat Management Options for Improving Industrial Process Heating Systems Waste Heat Management Options for Improving Industrial Process Heating Systems This presentation covers typical sources of waste heat from process heating equipment, characteristics of waste heat streams, and options for recovery including Combined Heat and Power. Waste Heat Management Options for Improving Industrial Process Heating Systems (August 20, 2009) (494.7 KB) More

  1. Heat Exchangers for Solar Water Heating Systems | Department of Energy

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

    Exchangers for Solar Water Heating Systems Heat Exchangers for Solar Water Heating Systems Image of a heat exchanger. | Photo from iStockphoto.com Image of a heat exchanger. | Photo from iStockphoto.com Solar water heating systems use heat exchangers to transfer solar energy absorbed in solar collectors to the liquid or air used to heat water or a space. Heat exchangers can be made of steel, copper, bronze, stainless steel, aluminum, or cast iron. Solar heating systems usually use copper,

  2. Properties of the Boltzmann equation in the classical approximation

    SciTech Connect (OSTI)

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

    2014-12-30

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

  3. Properties of the Boltzmann equation in the classical approximation

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

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

    2014-12-30

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

  4. Properties of the Boltzmann equation in the classical approximation

    SciTech Connect (OSTI)

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

    2014-12-30

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

  5. Comparison of natural convection heat exchangers for solar water heating systems

    SciTech Connect (OSTI)

    Davidson, J.; Liu, W.

    1998-09-15

    Thermosyphon heat exchangers are used in indirect solar water heating systems to avoid using a pump to circulate water from the storage tank to the heat exchanger. In this study, the authors consider the effect of heat exchanger design on system performance. They also compare performance of a system with thermosyphon flow to the same system with a 40W pump in the water loop. In the first part of the study, the authors consider the impact of heat exchanger design on the thermal performance of both one- and two-collector solar water heaters. The comparison is based on Solar Rating and Certification Corporation (SRCC) OG300 simulations. The thermosyphon heat exchangers considered are (1) a one-pass, double wall, 0.22 m{sup 2}, four tube-in-shell heat exchanger manufactured by AAA Service and Supply, Inc., (the Quad-Rod); (2) a two-pass, double wall, 0.2 m{sup 2}, tube-in-shell made by Heliodyne, Inc., but not intended for commercial development; (3) a one-pass, single wall, 0.28 m{sup 2}, 31 tube-in-shell heat exchanger from Young Radiator Company, and (4) a one-pass single-wall, 0.61 m{sup 2}, four coil-in-shell heat exchanger made by ThermoDynamics Ltd. The authors compare performance of the systems with thermosyphon heat exchangers to a system with a 40 W pump used with the Quad-Rod heat exchanger. In the second part of the study, the effects of reducing frictional losses through the heat exchanger and/or the pipes connecting the heat exchanger to the storage tank, and increasing heat transfer area are evaluated in terms of OG300 ratings.

  6. Wound tube heat exchanger

    DOE Patents [OSTI]

    Ecker, Amir L.

    1983-01-01

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

  7. Heat transfer system

    DOE Patents [OSTI]

    Not Available

    1980-03-07

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

  8. Heat transfer system

    DOE Patents [OSTI]

    McGuire, Joseph C.

    1982-01-01

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

  9. Higher-degree linear approximations of nonlinear systems

    SciTech Connect (OSTI)

    Karahan, S.

    1989-01-01

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

  10. Power Rates Announcements (pbl/rates)

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

    WP-10 Rate Case WP-07 Rate Case WP-07 Supplemental Rate Case ASC Methodology Adjustments (2007-2009) Adjustments (2002-2006) Previous Rate Cases Financial Choices (2003-06) Power...

  11. Current BPA Power Rates (pbl/rates)

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

    and Workshops WP-10 Rate Case WP-07 Rate Case WP-07 Supplemental Rate Case ASC Methodology Adjustments (2007-2009) Adjustments (2002-2006) Previous Rate Cases Financial...

  12. Communication: Improved pair approximations in local coupled-cluster methods

    SciTech Connect (OSTI)

    Schwilk, Max; Werner, Hans-Joachim; Usvyat, Denis

    2015-03-28

    In local coupled cluster treatments the electron pairs can be classified according to the magnitude of their energy contributions or distances into strong, close, weak, and distant pairs. Different approximations are introduced for the latter three classes. In this communication, an improved simplified treatment of close and weak pairs is proposed, which is based on long-range cancellations of individually slowly decaying contributions in the amplitude equations. Benchmark calculations for correlation, reaction, and activation energies demonstrate that these approximations work extremely well, while pair approximations based on local second-order Møller-Plesset theory can lead to errors that are 1-2 orders of magnitude larger.

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

    SciTech Connect (OSTI)

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

    1993-03-01

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

  14. Total Space Heat-

    Gasoline and Diesel Fuel Update (EIA)

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

  15. Fusion heating technology

    SciTech Connect (OSTI)

    Cole, A.J.

    1982-06-01

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

  16. 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 ...

  17. ARM - Heat Index Calculations

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

    Study Hall About ARM Global Warming FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans Heat Index Calculations Heat Index is an index that ...

  18. Electron Heat Transport Measured

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

    Heat Transport Measured in a Stochastic Magnetic Field T. M. Biewer, * C. B. Forest, ... limit of s &29; 1, RR assumed the electron heat flux to be diffusive, obeying Fourier's ...

  19. HEATING 7. 1 user's manual

    SciTech Connect (OSTI)

    Childs, K.W.

    1991-07-01

    HEATING is a FORTRAN program designed to solve steady-state and/or transient heat conduction problems in one-, two-, or three- dimensional Cartesian, cylindrical, or spherical coordinates. A model may include multiple materials, and the thermal conductivity, density, and specific heat of each material may be both time- and temperature-dependent. The thermal conductivity may be anisotropic. Materials may undergo change of phase. Thermal properties of materials may be input or may be extracted from a material properties library. Heating generation rates may be dependent on time, temperature, and position, and boundary temperatures may be time- and position-dependent. The boundary conditions, which may be surface-to-boundary or surface-to-surface, may be specified temperatures or any combination of prescribed heat flux, forced convection, natural convection, and radiation. The boundary condition parameters may be time- and/or temperature-dependent. General graybody radiation problems may be modeled with user-defined factors for radiant exchange. The mesh spacing may be variable along each axis. HEATING is variably dimensioned and utilizes free-form input. Three steady-state solution techniques are available: point-successive-overrelaxation iterative method with extrapolation, direct-solution (for one-dimensional or two-dimensional problems), and conjugate gradient. Transient problems may be solved using one of several finite-difference schemes: Crank-Nicolson implicit, Classical Implicit Procedure (CIP), Classical Explicit Procedure (CEP), or Levy explicit method (which for some circumstances allows a time step greater than the CEP stability criterion). The solution of the system of equations arising from the implicit techniques is accomplished by point-successive-overrelaxation iteration and includes procedures to estimate the optimum acceleration parameter.

  20. Evaluation of Heat Checking and Washout of Heat Resistant Superalloys...

    Office of Scientific and Technical Information (OSTI)

    Evaluation of Heat Checking and Washout of Heat Resistant Superalloys and Coatings for Die inserts Citation Details In-Document Search Title: Evaluation of Heat Checking and ...

  1. Buildings","All Buildings with Water Heating","Water-Heating...

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

    5. Water-Heating Energy Sources, Number of Buildings, 1999" ,"Number of Buildings (thousand)" ,"All Buildings","All Buildings with Water Heating","Water-Heating Energy Sources Used ...

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

    Office of Energy Efficiency and Renewable Energy (EERE)

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

  3. Integral approximations to classical diffusion and smoothed particle hydrodynamics

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

    Du, Qiang; Lehoucq, R. B.; Tartakovsky, A. M.

    2014-12-31

    The contribution of the paper is the approximation of a classical diffusion operator by an integral equation with a volume constraint. A particular focus is on classical diffusion problems associated with Neumann boundary conditions. By exploiting this approximation, we can also approximate other quantities such as the flux out of a domain. Our analysis of the model equation on the continuum level is closely related to the recent work on nonlocal diffusion and peridynamic mechanics. In particular, we elucidate the role of a volumetric constraint as an approximation to a classical Neumann boundary condition in the presence of physical boundary.more » The volume-constrained integral equation then provides the basis for accurate and robust discretization methods. As a result, an immediate application is to the understanding and improvement of the Smoothed Particle Hydrodynamics (SPH) method.« less

  4. Second post-Newtonian approximation of Einstein-aether theory

    SciTech Connect (OSTI)

    Xie Yi; Huang Tianyi

    2008-06-15

    In this paper, second post-Newtonian approximation of Einstein-aether theory is obtained by Chandrasekhar's approach. Five parametrized post-Newtonian parameters in first post-Newtonian approximation are presented after a time transformation and they are identical with previous works, in which {gamma}=1, {beta}=1, and two preferred-frame parameters remain. Meanwhile, in second post-Newtonian approximation, a parameter, which represents third order nonlinearity for gravity, is zero--the same as in general relativity. For an application for future deep space laser ranging missions, we reduce the metric coefficients for light propagation in a case of N point masses as a simplified model of the Solar System. The resulting light deflection angle in second post-Newtonian approximation poses another constraint on the Einstein-aether theory.

  5. Exact and approximate Kohn-Sham potentials in ensemble density...

    Office of Scientific and Technical Information (OSTI)

    Title: Exact and approximate Kohn-Sham potentials in ensemble density-functional theory Authors: Yang, Zeng-hui ; Trail, John R. ; Pribram-Jones, Aurora ; Burke, Kieron ; Needs, ...

  6. Abrasion resistant heat pipe

    DOE Patents [OSTI]

    Ernst, Donald M. (Leola, PA)

    1984-10-23

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

  7. Abrasion resistant heat pipe

    DOE Patents [OSTI]

    Ernst, D.M.

    1984-10-23

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

  8. Solar heat receiver

    DOE Patents [OSTI]

    Hunt, Arlon J.; Hansen, Leif J.; Evans, David B.

    1985-01-01

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

  9. MA HEAT Loan Overview

    Broader source: Energy.gov [DOE]

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

  10. Residential heating oil price

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

    heating oil price decreases The average retail price for home heating oil fell 7.6 cents from a week ago to $2.97 per gallon. That's down $1.05 from a year ago, based on the residential heating fuel survey by the U.S. Energy Information Administration. Heating oil prices in the New England region fell to $2.94 per gallon, down 6.7 cents from last week, and down $1.07

  11. Residential heating oil price

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

    heating oil price decreases The average retail price for home heating oil fell 6.3 cents from a week ago to $2.91 per gallon. That's down $1.10 from a year ago, based on the residential heating fuel survey by the U.S. Energy Information Administration. Heating oil prices in the New England region fell to $2.88 per gallon, down 6.8 cents from last week, and down $1.13

  12. Residential heating oil price

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

    heating oil price decreases The average retail price for home heating oil fell 7.5 cents from a week ago to $2.84 per gallon. That's down $1.22 from a year ago, based on the residential heating fuel survey by the U.S. Energy Information Administration. Heating oil prices in the New England region fell to $2.80 per gallon, down 7.4 cents from last week, and down $1.23

  13. Residential heating oil price

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

    heating oil price decreases The average retail price for home heating oil fell 4.1 cents from a week ago to $2.89 per gallon, based on the residential heating fuel survey by the U.S. Energy Information Administration. Heating oil prices in the New England region fell to $2.84 per gallon, down 5.4 cents from last week

  14. Residential heating oil price

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

    heating oil price decreases The average retail price for home heating oil fell 3.6 cents from a week ago to $3.04 per gallon. That's down 99.4 cents from a year ago, based on the residential heating fuel survey by the U.S. Energy Information Administration. Heating oil prices in the New England region fell to $3.01 per gallon, down 3.6 cents from last week, and down $1.01

  15. Solar heat receiver

    DOE Patents [OSTI]

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

    1982-09-29

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

  16. ARM - Evaluation Product - Broadband Heating Rate Profile Project...

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

    information on the BBHRP output files so that analysis of the output would be more straightforward. This new version of BBHRP, sgp1bbhrpripbeC1.c1, uses the RIPBE files as input to...

  17. Property:Heat Recovery Rating | Open Energy Information

    Open Energy Info (EERE)

    + 2,000 + Distributed Generation StudyPatterson Farms CHP System Using Renewable Biogas + 1,366,072 + Distributed Generation StudySUNY Buffalo + 600,000 + Distributed...

  18. Broadband Heating Rate Profile Project (BBHRP) - SGP ripbe370mcfarlane...

    Office of Scientific and Technical Information (OSTI)

    Additionally, an interface between the RIPBE input file and the RRTM was developed using the new ARM integrated software development environment (ISDE) and effort was put into ...

  19. Broadband Heating Rate Profile Project (BBHRP) - SGP ripbe1mcfarlane...

    Office of Scientific and Technical Information (OSTI)

    Additionally, an interface between the RIPBE input file and the RRTM was developed using the new ARM integrated software development environment (ISDE) and effort was put into ...

  20. Cloud Properties and Radiative Heating Rates for TWP (Dataset...

    Office of Scientific and Technical Information (OSTI)

    This Combined Remote Sensor Retrieval Algorithm (CombRet) produces vertical profiles of liquid or ice water content (LWC or IWC), droplet effective radius (re), ice crystal ...

  1. Heat pipes for industrial waste heat recovery

    SciTech Connect (OSTI)

    Merrigan, M.A.

    1981-01-01

    Development work on the high temperature ceramic recuperator at Los Alamos National Laboratory is described and involved material investigations, fabrication methods development, compatibility tests, heat pipe operation, and the modeling of application conditions based on current industrial usage. Solid ceramic heat pipes, ceramic coated refractory pipes, and high-temperature oxide protected metallic pipes have been investigated. Economic studies of the use of heat-pipe based recuperators in industrial furnaces have been conducted and payback periods determined as a function of material, fabrication, and installation cost.

  2. Waste Heat Recovery

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

    - PRE-DECISIONAL - DRAFT 1 Waste Heat Recovery 1 Technology Assessment 2 Contents 3 1. Introduction to the Technology/System ............................................................................................... 2 4 1.1. Introduction to Waste Heat Recovery .......................................................................................... 2 5 1.2. Challenges and Barriers for Waste Heat Recovery ..................................................................... 13 6 1.3. Public

  3. Liquid heat capacity lasers

    DOE Patents [OSTI]

    Comaskey, Brian J.; Scheibner, Karl F.; Ault, Earl R.

    2007-05-01

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

  4. HEAT TRANSFER MEANS

    DOE Patents [OSTI]

    Fraas, A.P.; Wislicenus, G.F.

    1961-07-11

    A heat exchanger is adapted to unifomly cool a spherical surface. Equations for the design of a spherical heat exchanger hav~g tubes with a uniform center-to-center spining are given. The heat exchanger is illustrated in connection with a liquid-fueled reactor.

  5. Heat pipe effect in porous medium

    SciTech Connect (OSTI)

    Joseph, M.

    1992-12-01

    In this thesis a parametric study of the thermal and hydrologic characteristics of the fractured porous tuffs at Yucca Mountain, Nevada was conducted. The effects of different fracture and matrix properties including permeability, thermal conductivity, specific heat, porosity, and tortuosity on heat pipe performance in the vicinity of the waste package were observed. Computer simulations were carried out using TOUGH code on a Cray YMP-2 supercomputer. None of the fracture parameters affected the heat pipe performance except the mobility of the liquid in the fracture. Matrix permeability and thermal conductivity were found to have significant effect on the heat pipe performance. The effect of mass injection was studied for liquid water and air injected at the fracture boundary. A high rate of mass injection was required to produce any effect on the heat pipe. The fracture-matrix equilibrium is influenced by the matrix permeability and the matrix thermal conductivity.

  6. Control system for fluid heated steam generator

    DOE Patents [OSTI]

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

    1984-05-29

    A control system for controlling the location of the nucleate-boiling region in a fluid heated steam generator comprises means for measuring the temperature gradient (change in temperature per unit length) of the heating fluid along the steam generator; means for determining a control variable in accordance with a predetermined function of temperature gradients and for generating a control signal in response thereto; and means for adjusting the feedwater flow rate in accordance with the control signal.

  7. Control system for fluid heated steam generator

    DOE Patents [OSTI]

    Boland, James F.; Koenig, John F.

    1985-01-01

    A control system for controlling the location of the nucleate-boiling region in a fluid heated steam generator comprises means for measuring the temperature gradient (change in temperature per unit length) of the heating fluid along the steam generator; means for determining a control variable in accordance with a predetermined function of temperature gradients and for generating a control signal in response thereto; and means for adjusting the feedwater flow rate in accordance with the control signal.

  8. Port Graham Biomass Community Heat Project

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

    Sink, Chugachmiut Recipient Principal Investigator For Port Graham Village Council US Department of Energy Office of Indian Energy & Economic Development-May 5, 2015 Port Graham population of 177 (2010 Census) Southern tip of Kenai Peninsula, about 28-miles off the road system from Homer, Alaska, accessible by air or water only Unemployment rate 22%; 44.6% out of labor force; Median household income $18,942 Heat 5-community buildings with cord wood biomass heating system Displace

  9. Geothermal Heat Pump Manufacturing Activities

    Gasoline and Diesel Fuel Update (EIA)

    defined as geothermal heat pump unit with all the necessary functional components, except for installation materials. These include geothermal heat pump, air handler, heat ...

  10. Solar Process Heat Basics | NREL

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

    Solar Process Heat Basics Commercial and industrial buildings may use the same solar technologies-photovoltaics, passive heating, daylighting, and water heating-that are used for ...

  11. A corrosive resistant heat exchanger

    DOE Patents [OSTI]

    Richlen, S.L.

    1987-08-10

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

  12. Current Power Rates

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

    links Financial Information Financial Public Processes Asset Management Cost Verification Process Rate Cases Rate Information Current Power Rates Current Transmission Rates...

  13. Current Transmission Rates

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

    links Financial Information Financial Public Processes Asset Management Cost Verification Process Rate Cases Rate Information Current Power Rates Current Transmission Rates...

  14. Previous Power Rates

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

    links Financial Information Financial Public Processes Asset Management Cost Verification Process Rate Cases Rate Information Current Power Rates Current Transmission Rates...

  15. Previous Transmission Rates

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

    links Financial Information Financial Public Processes Asset Management Cost Verification Process Rate Cases Rate Information Current Power Rates Current Transmission Rates...

  16. Heat recovery casebook

    SciTech Connect (OSTI)

    Lawn, J.

    1980-10-01

    Plants and factories could apply a great variety of sources and uses for valuable waste heat. Applications may be evaluated on the basis of real use for a specific waste heat, high-enough temperature and quality of work, and feasibility of mechanical heat transfer method. Classification may be by temperature, application, heat-transfer equipment, etc. Many buildings and industrial processes lend themselves well to heat-recovery strategies. Five case histories describe successful systems used by the Continental Corporation Data Center; Nabisco, Inc.; Kasper Foundry Company; Seven Up Bottling Company of Indiana; and Lehr Precision Tool company. (DCK)

  17. 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.

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

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

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

  19. Heat pump apparatus

    DOE Patents [OSTI]

    Nelson, Paul A.; Horowitz, Jeffrey S.

    1983-01-01

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

  20. SU-E-T-196: Heat Diffusion Modeling for Digital Holographic Interferometry Dosimetry

    SciTech Connect (OSTI)

    Cavan, A; Meyer, J

    2014-06-01

    Purpose: We have previously demonstrated that with Digital Holographic Interferometry (DHI) 2D spatial calorimetric measurements of high dose rate radiation sources can be obtained. The impact of heat transfer must be considered when undertaking any form of calorimetric measurement, as the radiation induced temperature distributions are subject to degradation due to heat diffusion. Unaccounted for, this limits the accuracy of the approach especially for long delivery times. Methods: 3D modelling of the heat diffusion in water was undertaken, and two different approaches developed to account for this effect. The mathematical framework to describe heat diffusion in 3D was applied, with the differential equations solved numerically using an implicit method. The first approach involved the comparison of the DHI measurements to an independent dose model of the source. The model was forward modeled to account for the heat diffusion during irradiation, allowing a direct comparison to validate the measured results. The second approach involved the correction of the measured data directly, by comparing the temperature distribution of two instances and subtracting the effects of heat diffusion of the first distribution from the second instance. This required the use of the Abel transform to approximate the 3D dose distribution from the 2D DHI results, thus limiting the approach to radiation applications possessing cylindrical symmetry. Results: The first approach resulted in higher accuracy and was more straightforward, but has a major limitation in that the measured results are only able to be utilized in comparison with an independent dose model. The applicability of the second approach is affected by noise in the measurement data and introduces higher uncertainties, but results in higher usability of the final data. Conclusion: Both approaches were implemented, and if used in conjunction would provide the most utility for the interpretation and use of DHI measurements.

  1. Active microchannel heat exchanger

    DOE Patents [OSTI]

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

    2001-01-01

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

  2. ACHILLES: Heat Transfer in PWR Core During LOCA Reflood Phase

    Energy Science and Technology Software Center (OSTI)

    2013-11-01

    1. NAME AND TITLE OF DATA LIBRARY ACHILLES -Heat Transfer in PWR Core During LOCA Reflood Phase. 2. NAME AND TITLE OF DATA RETRIEVAL PROGRAMS N/A 3. CONTRIBUTOR AEA Technology, Winfrith Technology Centre, Dorchester DT2 8DH United Kingdom through the OECD Nuclear Energy Agency Data Bank, Issy-les-Moulineaux, France. 4. DESCRIPTION OF TEST FACILITY The most important features of the Achilles rig were the shroud vessel, which contained the test section, and the downcomer. These maymore » be thought of as representing the core barrel and the annular downcomer in the reactor pressure vessel. The test section comprises a cluster of 69 rods in a square array within a circular shroud vessel. The rod diameter and pitch (9.5 mm and 12.6 mm) were typical of PWR dimensions. The internal diameter of the shroud vessel was 128 mm. Each rod was electrically heated over a length of 3.66 m, which is typical of the nuclear heated length in a PWR fuel rod, and each contained 6 internal thermocouples. These were arranged in one of 8 groupings which concentrated the thermocouples in different axial zones. The spacer grids were at prototypic PWR locations. Each grid had two thermocouples attached to its trailing edge at radial locations. The axial power profile along the rods was an 11 step approximation to a "chopped cosine". The shroud vessel had 5 heating zones whose power could be independently controlled. 5. DESCRIPTION OF TESTS The Achilles experiments investigated the heat transfer in the core of a Pressurized Water Reactor during the re-flood phase of a postulated large break loss of coolant accident. The results provided data to validate codes and to improve modeling. Different types of experiments were carried out which included single phase cooling, re-flood under low flow conditions, level swell and re-flood under high flow conditions. Three series of experiments were performed. The first and the third used the same test section but the second used another test section

  3. ACHILLES: Heat Transfer in PWR Core During LOCA Reflood Phase

    SciTech Connect (OSTI)

    2013-11-01

    1. NAME AND TITLE OF DATA LIBRARY ACHILLES -Heat Transfer in PWR Core During LOCA Reflood Phase. 2. NAME AND TITLE OF DATA RETRIEVAL PROGRAMS N/A 3. CONTRIBUTOR AEA Technology, Winfrith Technology Centre, Dorchester DT2 8DH United Kingdom through the OECD Nuclear Energy Agency Data Bank, Issy-les-Moulineaux, France. 4. DESCRIPTION OF TEST FACILITY The most important features of the Achilles rig were the shroud vessel, which contained the test section, and the downcomer. These may be thought of as representing the core barrel and the annular downcomer in the reactor pressure vessel. The test section comprises a cluster of 69 rods in a square array within a circular shroud vessel. The rod diameter and pitch (9.5 mm and 12.6 mm) were typical of PWR dimensions. The internal diameter of the shroud vessel was 128 mm. Each rod was electrically heated over a length of 3.66 m, which is typical of the nuclear heated length in a PWR fuel rod, and each contained 6 internal thermocouples. These were arranged in one of 8 groupings which concentrated the thermocouples in different axial zones. The spacer grids were at prototypic PWR locations. Each grid had two thermocouples attached to its trailing edge at radial locations. The axial power profile along the rods was an 11 step approximation to a "chopped cosine". The shroud vessel had 5 heating zones whose power could be independently controlled. 5. DESCRIPTION OF TESTS The Achilles experiments investigated the heat transfer in the core of a Pressurized Water Reactor during the re-flood phase of a postulated large break loss of coolant accident. The results provided data to validate codes and to improve modeling. Different types of experiments were carried out which included single phase cooling, re-flood under low flow conditions, level swell and re-flood under high flow conditions. Three series of experiments were performed. The first and the third used the same test section but the second used another test section, similar in

  4. Subsurface heaters with low sulfidation rates

    DOE Patents [OSTI]

    John, Randy Carl; Vinegar, Harold J

    2013-12-10

    A system for heating a hydrocarbon containing formation includes a heater having an elongated ferromagnetic metal heater section. The heater is located in an opening in a formation. The heater section is configured to heat the hydrocarbon containing formation. The exposed ferromagnetic metal has a sulfidation rate that goes down with increasing temperature of the heater, when the heater is in a selected temperature range.

  5. Variational principles with Pad approximants for tearing mode analysis

    SciTech Connect (OSTI)

    Cole, Andrew J.; Finn, John M.

    2014-03-15

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

  6. 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.

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

    SciTech Connect (OSTI)

    Xing, Lu; Cullin, James; Spitler, Jeffery; Im, Piljae; Fisher, Daniel

    2011-01-01

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

  8. Geothermal Heat Pump Manufacturing Activities

    Gasoline and Diesel Fuel Update (EIA)

    ARI-320 Water-Source Heat Pumps 10 ARI-325 Ground Water-Source Heat Pumps 13 ARI-330 Ground Source Closed-Loop Heat Pumps 11 ARI-870 Direct Geoexhange Heat Pumps 2 Other Non-ARI ...

  9. PNCA-02 Rate Case (rates/ratecases)

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

    Proposed Adjustment to the Rate for Interchange Energy Imbalances Under the Pacific Northwest Coordination Agreement (PNCA-02 Rate Case) (updated on April 26, 2002) BPA has issued...

  10. Fokker-Planck approximation of monoenergetic transport processes

    SciTech Connect (OSTI)

    Boergers, C.; Larsen, E.W.

    1994-12-31

    For transport problems with highly forward-peaked scattering, the transport equation is often approximated by the Fokker-Planck equation or, if large-angle scattering is deemed sufficiently important, by the Boltzmann-Fokker-Planck equation. In this paper, we state a simple, necessary, and sufficient condition for the validity of the simpler Fokker-Planck approximation for monoenergetic particle transport. We also show that for screened Rutherford scattering, the Fokker-Planck approximation is only marginally valid and is inaccurate unless the scattering is extremely forward peaked. (The same is true for more sophisticated models of elastic scattering of charged particles. In this paper, we restrict ourselves to screened Rutherford scattering for simplicity). More details on the results presented here will be given in forthcoming publications.