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1

Inverse bremsstrahlung heating rate in xenon clusters in the eikonal approximation  

SciTech Connect (OSTI)

We report inverse bremsstrahlung (IB) heating rates in the eikonal approximation (EA). The present analysis is performed using the plasma-screened Rogers and Debye potentials for Xe clusters with two different charge states (6 and 10). We compare the eikonal results with the first Born approximation (FBA) and classical-simulation (CL-sim) (Moll et al., Phys. Plasmas 19, 033303 (2012)) calculations for clusters in infrared light. Calculations have been performed for the field strength of 2.6 Multiplication-Sign 10{sup 8} V/cm. We find that compared to the FBA and CL-sim methods, the IB heating rate in the EA is less sensitive to the choice of the two potentials considered here. The present EA calculation shows that the influence of the inner structure of atomic ion on the heating rate is more prominent for the smaller ion charge (Xe{sup 6+}). In the case of low laser field approximation based on the elastic transport cross sections, it is seen that in contrast to the FBA and classical methods, the heating rate predicted by the EA does not deviate much all over the range of mean kinetic energy of electrons (20-500 eV) considered here for both the charge states of xenon (Xe{sup 6+} and Xe{sup 10+}). Furthermore, for the Rogers potential, EA is found to be in closer agreement with the classical method than the FBA. We also compare the results of the IB heating rate using the present and low-field approximation approaches to the above three methods and observe that the magnitudes of the IB heating rate calculated in the low field approximation are, in general, higher than the corresponding values predicted by the present approach for both the electron-ion potentials.

Dey, R. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Roy, A. C. [School of Mathematical Sciences, Ramakrishna Mission Vivekananda University, Belur Math, 711202 West Bengal (India)

2013-03-15T23:59:59.000Z

2

An Efficient Approximation of the Coronal Heating Rate for use in Global Sun-Heliosphere Simulations  

Science Journals Connector (OSTI)

The origins of the hot solar corona and the supersonically expanding solar wind are still the subject of debate. A key obstacle in the way of producing realistic simulations of the Sun-heliosphere system is the lack of a physically motivated way of specifying the coronal heating rate. Recent one-dimensional models have been found to reproduce many observed features of the solar wind by assuming the energy comes from Alfvén waves that are partially reflected, then dissipated by magnetohydrodynamic turbulence. However, the nonlocal physics of wave reflection has made it difficult to apply these processes to more sophisticated (three-dimensional) models. This paper presents a set of robust approximations to the solutions of the linear Alfvén wave reflection equations. A key ingredient of the turbulent heating rate is the ratio of inward-to-outward wave power, and the approximations developed here allow this to be written explicitly in terms of local plasma properties at any given location. The coronal heating also depends on the frequency spectrum of Alfvén waves in the open-field corona, which has not yet been measured directly. A model-based assumption is used here for the spectrum, but the results of future measurements can be incorporated easily. The resulting expression for the coronal heating rate is self-contained, computationally efficient, and applicable directly to global models of the corona and heliosphere. This paper tests and validates the approximations by comparing the results to exact solutions of the wave transport equations in several cases relevant to the fast and slow solar wind.

Steven R. Cranmer

2010-01-01T23:59:59.000Z

3

An Efficient Approximation of the Coronal Heating Rate for Use in Global Sun-Heliosphere Simulations  

E-Print Network [OSTI]

The origins of the hot solar corona and the supersonically expanding solar wind are still the subject of debate. A key obstacle in the way of producing realistic simulations of the Sun-heliosphere system is the lack of a physically motivated way of specifying the coronal heating rate. Recent one-dimensional models have been found to reproduce many observed features of the solar wind by assuming the energy comes from Alfven waves that are partially reflected, then dissipated by magnetohydrodynamic turbulence. However, the nonlocal physics of wave reflection has made it difficult to apply these processes to more sophisticated (three-dimensional) models. This paper presents a set of robust approximations to the solutions of the linear Alfven wave reflection equations. A key ingredient to the turbulent heating rate is the ratio of inward to outward wave power, and the approximations developed here allow this to be written explicitly in terms of local plasma properties at any given location. The coronal heating al...

Cranmer, Steven R

2009-01-01T23:59:59.000Z

4

Solar Heating Rates: The Importance of Spherical Geometry  

Science Journals Connector (OSTI)

A crucial component of any GCM is a scheme for calculating atmospheric heating rates. Since a detailed treatment of all processes involved is time consuming, many approximations are usually made. An approximation used in virtually all GCM ...

D. J. Lary; M. Balluch

1993-12-01T23:59:59.000Z

5

ARM - Measurement - Radiative heating rate  

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

govMeasurementsRadiative heating rate 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 list of all available measurements, including those recorded for diagnostic or quality assurance purposes. External Instruments MOLTS : Model Output Location Time Series Datastreams MOLTS : Model Output Location Time Series Datastreams MOLTSEDASSNDCLASS1 : Model Output Loc. Time Ser. (MOLTS): EDAS

6

Heat flow in the postquasistatic approximation  

SciTech Connect (OSTI)

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

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

2010-08-15T23:59:59.000Z

7

Heat flow in the postquasistatic approximation  

E-Print Network [OSTI]

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

B. Rodríguez-Mueller; C. Peralta; W. Barreto; L. Rosales

2010-05-10T23:59:59.000Z

8

Combined Retrieval, Microphysical Retrievals and Heating Rates  

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

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

Feng, Zhe

9

Inverse bremsstrahlung heating rate for dense plasmas in laser fields  

SciTech Connect (OSTI)

We report a theoretical analysis of inverse bremsstrahlung heating rate in the eikonal approximation. The present analysis is performed for a dense plasma using the screened electron-ion interaction potential for the ion charge state Z{sub i} = 1 and for both the weak and strong plasma screening cases. We have also compared the eikonal results with the first Born approximation (FBA) [M. Moll et al., New J. Phys. 14, 065010 (2012)] calculation. We find that the magnitudes of inverse bremsstrahlung heating rate within the eikonal approximation (EA) are larger than the FBA values in the weak screening case (? = 0.03 a.u.) in a wide range of field strength for three different initial electron momenta (2, 3, and 4 a.u.). But for strong screening case (? = 0.3 a.u.), the heating rates predicted by the two approximations do not differ much after reaching their maximum values. Furthermore, the individual contribution of photoemission and photoabsorption processes to heating rate is analysed for both the weak and strong screening cases. We find that the single photoemission and photoabsorption rates are the same throughout the field strength while the multiphoton absorption process dominates over the multiphoton emission process beyond the field strength ? 4×10{sup 8} V/cm. The present study of the dependence of heating rate on the screening parameter ranging from 0.01 to 20 shows that whereas the heating rate predicted by the EA is greater than the FBA up to the screening parameter ? = 0.3 a.u., the two approximation methods yield results which are nearly identical beyond the above value.

Dey, R. [D-203, Samruddhi Residency, Motera, Ahmedabad-380009, Gujarat (India)] [D-203, Samruddhi Residency, Motera, Ahmedabad-380009, Gujarat (India); Roy, A. C. [School of Mathematical Sciences, Ramakrishna Mission Vivekananda University, Belur Math 711202, West Bengal (India)] [School of Mathematical Sciences, Ramakrishna Mission Vivekananda University, Belur Math 711202, West Bengal (India)

2013-07-15T23:59:59.000Z

10

Heating Rate Profiles in Galaxy Clusters  

E-Print Network [OSTI]

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

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

2006-01-05T23:59:59.000Z

11

Property:HeatRate | Open Energy Information  

Open Energy Info (EERE)

HeatRate HeatRate Jump to: navigation, search This is a property of type Number. Pages using the property "HeatRate" Showing 25 pages using this property. (previous 25) (next 25) A AES Mendota Biomass Facility + 17,873.6 + APS Biomass I Biomass Facility + 8,911 + Acme Landfill Biomass Facility + 12,916.67 + Adrian Energy Associates LLC Biomass Facility + 13,170.6 + Agrilectric Power Partners Ltd Biomass Facility + 17,327.1 + Al Turi Biomass Facility + 15,600.2 + Alabama Pine Pulp Biomass Facility + 15,826.23 + Albany Landfill Gas Utilization Project Biomass Facility + 11,913.9 + Altamont Gas Recovery Biomass Facility + 10,500 + American Canyon Power Plant Biomass Facility + 10,886.8 + American Ref-Fuel of Delaware Valley Biomass Facility + 18,674.9 +

12

Fabrication and heating rate study of microscopic surface electrode ion traps  

E-Print Network [OSTI]

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

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

2010-09-15T23:59:59.000Z

13

Broadband Heating Rate Profile Project (BBHRP) - SGP ripbe1mcfarlane  

SciTech Connect (OSTI)

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.

Riihimaki, Laura; Shippert, Timothy

2014-11-05T23:59:59.000Z

14

Broadband Heating Rate Profile Project (BBHRP) - SGP ripbe370mcfarlane  

SciTech Connect (OSTI)

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.

Riihimaki, Laura; Shippert, Timothy

2014-11-05T23:59:59.000Z

15

Broadband Heating Rate Profile Project (BBHRP) - SGP ripbe1mcfarlane  

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

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.

Riihimaki, Laura; Shippert, Timothy

16

Broadband Heating Rate Profile Project (BBHRP) - SGP ripbe370mcfarlane  

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

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.

Riihimaki, Laura; Shippert, Timothy

17

Microbase Cloud Products and Associated Heating Rates in the...  

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...

18

Method of calculation of heat generation rates for DWPF glass  

SciTech Connect (OSTI)

The Waste Acceptance Preliminary Specifications (WAPS) require estimates of the heat generation rate of DWPF waste glasses. Estimates of the heat generation rates of projected glass compositions are to be reported in the Waste Form Qualification Report. Similar estimates for actual production glasses are to be reported in the Production Records. In this report, a method of calculating the heat generation rate from the radionuclide inventory is provided. Application of the method to the DWPF Design-Basis glass indicates that the heat generation rate can be accurately estimated from the Sr-90, Y-90, Cs-137, Ba-137m, and Pu-238 contents alone.

Plodinec, M.J.

1992-03-17T23:59:59.000Z

19

Method of calculation of heat generation rates for DWPF glass  

SciTech Connect (OSTI)

The Waste Acceptance Preliminary Specifications (WAPS) require estimates of the heat generation rate of DWPF waste glasses. Estimates of the heat generation rates of projected glass compositions are to be reported in the Waste Form Qualification Report. Similar estimates for actual production glasses are to be reported in the Production Records. In this report, a method of calculating the heat generation rate from the radionuclide inventory is provided. Application of the method to the DWPF Design-Basis glass indicates that the heat generation rate can be accurately estimated from the Sr-90, Y-90, Cs-137, Ba-137m, and Pu-238 contents alone.

Plodinec, M.J.

1993-02-04T23:59:59.000Z

20

Tables for solution of the heat-conduction equation with a time-dependent heating rate  

E-Print Network [OSTI]

Tables are presented for the solution of the transient onedimensional heat flow in a solid body of constant material properties with the heating rate at one boundary dependent on time. These tables allow convenient and ...

Bergles A. E.

1962-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

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

E-Print Network [OSTI]

369 Influence of Heat Transmission Mode on Heating Rates and on the Selection of Patches for Heating in a Mediterranean Lizard Josabel Belliure* Luis M. Carrascal Department of Evolutionary Ecology´ Gutie´rrez Abascal 2, 28006 Madrid, Spain Accepted 6/6/02 ABSTRACT Heliothermy (heat gain by radiation

Carrascal, Luis M.

22

Numerical approximation of null controls for the heat equation through transmutation  

E-Print Network [OSTI]

Numerical approximation of null controls for the heat equation through transmutation Arnaud M components: Fourier filtering, Tychonoff regularization, mixed finite element methods, multi-grid strategies this issue for the heat equation, which is the op- posite paradigm because of its strong dissipativity

Sart, Remi

23

ARM - Evaluation Product - Broadband Heating Rate Profile Project (BBHRP)  

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

ProductsBroadband Heating Rate Profile Project ProductsBroadband Heating Rate Profile Project (BBHRP) Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : Broadband Heating Rate Profile Project (BBHRP) 2000.03.01 - 2006.02.28 Site(s) SGP General Description 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

24

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 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 Northwest National Laboratory Flynn, Connor Pacific Northwest National Laboratory Sivaraman, Chitra Pacific Northwest National Laboratory Turner, David University of Wisconsin-Madison Heck, Patrick University of Wisconsin Rutan, David Analytical Services & Materials, Inc.

25

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

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

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...

26

Prediction of the heat release rate of wood  

SciTech Connect (OSTI)

A model for the heat release rate of wood during flaming combustion was developed during this research. It includes the effects of char shrinkage, multiple chemical components, adsorbed moisture, internal convective cooling and the variation of the thermophysical and thermochemical properties with temperature and the mass retention fraction of the char. It does not include char oxidation or diffusion of moisture and volatile pyrolysis products toward the rear surface. It calculates the time to ignition, mass burning rate, heat release rate, heat of combustion, heat of gasification and depth of char. An important part of this research was the determination of the thermochemical and thermophysical properties required by the model. An apparatus was developed for determining the kinetic parameters and the heat of combustion of the volatiles under conditions similar to those in the interior of a flaming slab of wood. Data were obtained on each of the four major chemical components present in Douglas fir. Thermal diffusivity measurements on Douglas fir and its char yielded an average value of 2.1 {times} 10{sup {minus}7} s{sup 2}/s which was nearly independent of temperature and mass retention fraction of the char for temperature sup to 500{degree}C and for mass-retention fractions above 0.30.

Parker, W.J.

1988-01-01T23:59:59.000Z

27

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 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 atmosphere (TOA) radiative fluxes to various parameter- izations of clouds and cloud microphysics. The SCM was run at the Atmospheric Radiation Measurement (ARM) Program's Southern Great Plains (SGP), Tropical Western Pacific (TWP), and North Slope of Alaska (NSA) sites using forcing data derived from forecast products. The forecast

28

Standby Rates for Combined Heat and Power Systems  

SciTech Connect (OSTI)

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.

Sedano, Richard [Regulatory Assistance Partnership; Selecky, James [Brubaker & Associates, Inc.; Iverson, Kathryn [Brubaker & Associates, Inc.; Al-Jabir, Ali [Brubaker & Associates, Inc.

2014-02-01T23:59:59.000Z

29

Cloud Properties and Radiative Heating Rates for TWP  

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

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.

Comstock, Jennifer

30

Cloud Properties and Radiative Heating Rates for TWP  

SciTech Connect (OSTI)

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.

Comstock, Jennifer

2013-11-07T23:59:59.000Z

31

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

E-Print Network [OSTI]

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

Virginia Tech

32

Property:Heat Recovery Rating | Open Energy Information  

Open Energy Info (EERE)

Rating Rating Jump to: navigation, search This is a property of type Number. Pages using the property "Heat Recovery Rating" Showing 22 pages using this property. D Distributed Generation Study/10 West 66th Street Corp + 300,000 + Distributed Generation Study/615 kW Waukesha Packaged System + 2,500,000 + Distributed Generation Study/Aisin Seiki G60 at Hooligans Bar and Grille + 46,105 + Distributed Generation Study/Arrow Linen + 3,000,000 + Distributed Generation Study/Dakota Station (Minnegasco) + 290,000 + Distributed Generation Study/Elgin Community College + 11,200,000 + Distributed Generation Study/Emerling Farm + 2,000,000 + Distributed Generation Study/Floyd Bennett + 230,000 + Distributed Generation Study/Harbec Plastics + 3,750,000 + Distributed Generation Study/Hudson Valley Community College + 32,500,000 +

33

Insensitivity of the rate of ion motional heating to trap-electrode material over a large temperature range  

E-Print Network [OSTI]

We present measurements of trapped-ion motional-state heating rates in niobium and gold surface-electrode ion traps over a range of trap-electrode temperatures from approximately 4 K to room temperature (295 K) in a single ...

Chiaverini, John

34

Convergence rates of best N-term Galerkin approximations for a class of elliptic sPDEs  

E-Print Network [OSTI]

y U are established. These estimates are of the form N-r , where the rate of convergence r depends only on the decay of the random input expansion. It is shown that r exceeds the benchmark rate 1 of freedom Nd.o.f can be obtained. Here the rate s is determined by both the best N-term approximation rate r

Cohen, Albert

35

Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions  

E-Print Network [OSTI]

Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions by Carl, Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions KTH Nuclear Reactor power is limited by a phenomenon called critical heat flux (CHF). It appears as a sudden detoriation

Haviland, David

36

High rate heating driven decomposition of energetic materials: Diagnostics evaluation  

SciTech Connect (OSTI)

Combustion of energetic materials involves processes in both gas and condensed phases and is governed by coupled thermal, physical, and chemical phenomena. Development of reliable models for design, performance, stability, and hazard analyses requires detailed understanding of three general chemical reaction regimes: (1) initial condensed-phase decomposition, (2) subsequent interaction of decomposition products with the remaining condensed phase, and (3) gas-phase reaction of decomposition products to form the ultimate combustion products. The first two regimes are the least understood and most difficult to study, particularly the initial condensed-phase decomposition. The basic difficulty in studying condensed phase phenomena has been the inability to probe directly chemistry in the condensed phase under isothermal condition and with the spatial and temporal resolution needed at higher temperatures and reaction rates. Thin-film samples provide a means to study condensed-phase chemistry at isothermal conditions and with microsecond temporal resolution. We are developing an experiment system that employs rapidly heated thin- film samples and multiple diagnostics to examine condensed-phase chemistry and monitor evolved gas species. Results from our initial work have been encouraging. Thin-film samples of several energetic materials have been prepared and appear to be representative of bulk materials. Furthermore, preliminary experiments indicate that all the use of these samples with two chemical diagnostic techniques, time-of- flight mass spectrometry (TOFMS) and time-resolved infrared spectral photography (TRISP), is viable. 5 refs., 8 figs.

Trott, W.M.; Renlund, A.M.; Erickson, K.L.; Skocypec, R.D.

1991-01-01T23:59:59.000Z

37

High rate heating driven decomposition of energetic materials: Diagnostics evaluation  

SciTech Connect (OSTI)

Combustion of energetic materials involves processes in both gas and condensed phases and is governed by coupled thermal, physical, and chemical phenomena. Development of reliable models for design, performance, stability, and hazard analyses requires detailed understanding of three general chemical reaction regimes: (1) initial condensed-phase decomposition, (2) subsequent interaction of decomposition products with the remaining condensed phase, and (3) gas-phase reaction of decomposition products to form the ultimate combustion products. The first two regimes are the least understood and most difficult to study, particularly the initial condensed-phase decomposition. The basic difficulty in studying condensed phase phenomena has been the inability to probe directly chemistry in the condensed phase under isothermal condition and with the spatial and temporal resolution needed at higher temperatures and reaction rates. Thin-film samples provide a means to study condensed-phase chemistry at isothermal conditions and with microsecond temporal resolution. We are developing an experiment system that employs rapidly heated thin- film samples and multiple diagnostics to examine condensed-phase chemistry and monitor evolved gas species. Results from our initial work have been encouraging. Thin-film samples of several energetic materials have been prepared and appear to be representative of bulk materials. Furthermore, preliminary experiments indicate that all the use of these samples with two chemical diagnostic techniques, time-of- flight mass spectrometry (TOFMS) and time-resolved infrared spectral photography (TRISP), is viable. 5 refs., 8 figs.

Trott, W.M.; Renlund, A.M.; Erickson, K.L.; Skocypec, R.D.

1991-12-01T23:59:59.000Z

38

Stellar electron-capture rates calculated with the finite-temperature relativistic random-phase approximation  

E-Print Network [OSTI]

We introduce a self-consistent microscopic theoretical framework for modelling the process of electron capture on nuclei in stellar environment, based on relativistic energy density functionals. The finite-temperature relativistic mean-field model is used to calculate the single-nucleon basis and the occupation factors in a target nucleus, and $J^{\\pi} = 0^{\\pm}$, $1^{\\pm}$, $2^{\\pm}$ charge-exchange transitions are described by the self-consistent finite-temperature relativistic random-phase approximation. Cross sections and rates are calculated for electron capture on 54,56Fe and 76,78Ge in stellar environment, and results compared with predictions of similar and complementary model calculations.

YiFei Niu; Nils Paar; Dario Vretenar; Jie Meng

2011-04-09T23:59:59.000Z

39

Numerical study of the global axisymmetric circulation with varying heating and rotation rates  

SciTech Connect (OSTI)

A steady, axisymmetric model of the general circulation is developed as a basis for climate stability studies. The model includes the effects of heating, rotation, and internal friction, but neglects topography. It is assumed that the axisymmetric flow may be modeled by making the Boussinesq and deep convection approximations. The three unknowns are assumed to satisfy appropriate spectral expansions, and the three equations are then rearranged into a Galerkin representation. The number of degrees of freedom retained in the expansions is restricted to eight waves or less, which places the model in the class of highly truncated spectral models. The motions are forced by a specified heating distribution and dissipated through an eddy mixing coefficient formulation. The axisymmetric circulation is tested for stability to quasi-geostrophic disturbances. The orignial set of five primitive equations is reduced to a single equation governing the evolution of quasi-geostrophic potential vorticity. This equation is linearized about the axisymmetric state, and the stability of the disturbances is found by examining the eigenvalues associated with each disturbance. The application of the Boussinesq, deep convection, and quasi-geostrophic assumptions limits the ranges of the heating and rotation rates. For values not too far from typical atmospheric values, the model produces a stability boundary separating Rossby and Hadley flow.

Henderson, H.W.

1982-01-01T23:59:59.000Z

40

Heat resistance and outgrowth of clostridium perfringens spores as affected by the type of heating medium, and heating and cooling rates in ground pork  

E-Print Network [OSTI]

) and cured ground pork (CGP) at 75ºC. The effect of the heating rate on HR, germination and outgrowth of C. perfringens spores in CGP was determined by increasing the temperature from 20 to 75ºC at a rate of 4, 8, and 12ºC/h prior to heating and holding at 75...

Marquez Gonzalez, Mayra

2009-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

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

SciTech Connect (OSTI)

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.

Riihimaki, Laura; Shippert, Timothy

2014-11-05T23:59:59.000Z

42

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

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

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.

Riihimaki, Laura; Shippert, Timothy

43

Method of calculation of heat generation rates for DWPF glass. Revision 1  

SciTech Connect (OSTI)

The Waste Acceptance Preliminary Specifications (WAPS) require estimates of the heat generation rate of DWPF waste glasses. Estimates of the heat generation rates of projected glass compositions are to be reported in the Waste Form Qualification Report. Similar estimates for actual production glasses are to be reported in the Production Records. In this report, a method of calculating the heat generation rate from the radionuclide inventory is provided. Application of the method to the DWPF Design-Basis glass indicates that the heat generation rate can be accurately estimated from the Sr-90, Y-90, Cs-137, Ba-137m, and Pu-238 contents alone.

Plodinec, M.J.

1992-03-17T23:59:59.000Z

44

Method of calculation of heat generation rates for DWPF glass. Revision 2  

SciTech Connect (OSTI)

The Waste Acceptance Preliminary Specifications (WAPS) require estimates of the heat generation rate of DWPF waste glasses. Estimates of the heat generation rates of projected glass compositions are to be reported in the Waste Form Qualification Report. Similar estimates for actual production glasses are to be reported in the Production Records. In this report, a method of calculating the heat generation rate from the radionuclide inventory is provided. Application of the method to the DWPF Design-Basis glass indicates that the heat generation rate can be accurately estimated from the Sr-90, Y-90, Cs-137, Ba-137m, and Pu-238 contents alone.

Plodinec, M.J.

1993-02-04T23:59:59.000Z

45

Heat transfer rate of a closed-loop oscillating heat pipe with check valves using silver nanofluid as working fluid  

Science Journals Connector (OSTI)

This research investigated the effect of aspect ratios (evaporator length to inner diameter of capillary tube), inclination angles, and concentrations of silver nanofluid on the heat transfer rate of a closed-loo...

S. Wannapakhe; S. Rittidech; B. Bubphachot…

2009-06-01T23:59:59.000Z

46

Journal of Thermal Biology 33 (2008) 711 Physiological and behavioral control of heating and cooling rates  

E-Print Network [OSTI]

; Cooling rate; Heating rate; Physiological thermoregulation; Rubber boa; Temperature 1. Introduction Body temperature greatly impacts the ecology, behavior, and physiology of reptiles (Huey, 1982; Peterson, 1987; Peterson et al., 1993). Consequently, many species of reptiles thermoregulate to maintain body temperatures

Dorcas, Michael E.

47

Effect of Turbulence Fluctuations on Surface Heating Rate in Hypersonic Turbulent  

E-Print Network [OSTI]

Effect of Turbulence Fluctuations on Surface Heating Rate in Hypersonic Turbulent Boundary Layers) of reacting hypersonic turbulent boundary layers at conditions typical of reen- try vehicles. Surface heat in designing hypersonic vehicles is to predict aerothermo- dynamic heating. When the boundary layer

Martín, Pino

48

Evidence for thermalization of surface-desorbed molecules at heating rates of 108  

E-Print Network [OSTI]

Evidence for thermalization of surface-desorbed molecules at heating rates of 108 K/s C. R of aniline-d7 from a single-crystal surface 0001 of sapphire Al2O3 at a heating rate on the order of 108 K.e., pulsed heating of the sapphire surface on the nanosecond time scale leads to thermal desorption and rapid

Zare, Richard N.

49

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 ProductsCloud Properties and Radiative Heating Rates for TWP 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 2002.01.01 - 2012.02.08 Site(s) TWP General Description 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

50

Generalized constructal optimization for solidification heat transfer process of slab continuous casting based on heat loss rate  

Science Journals Connector (OSTI)

Abstract Based on constructal theory, generalized constructal optimization of a solidification heat transfer process of slab continuous casting is carried out by taking a complex function as optimization objective. The complex function is composed of the functions of the heat loss rate and surface temperature gradient of the slab subjected to the constraints of shell thickness, surface temperature and liquid core length of the slab. For the specified total water flow rate, the “optimal construct” of the water distribution in the secondary cooling zone is obtained. Comparing the optimal results with the initial ones, it is shown that the complex function, the functions of the heat loss rate and the surface temperature gradient after optimization are decreased by 35.04%, 2.14% and 59.48%, respectively. Therefore, the scheme of the “optimal construct” of the water distribution reduces the heat loss rate and surface temperature gradient of the slab simultaneously, that is, improves its energy retention and quality simultaneously. The optimization results obtained in this paper can provide some guidelines for parameter designs and dynamic operations of the solidification heat transfer process of slab continuous casting.

Huijun Feng; Lingen Chen; Zhihui Xie; Zemin Ding; Fengrui Sun

2014-01-01T23:59:59.000Z

51

Approximating the solar/stellar energy generation rate, luminosity gradient, and the hydrogen content  

Science Journals Connector (OSTI)

In this paper we wish to develop an analytical technique for modelling the energy generation rate and the luminosity gradient for ... 1989) we derive dimensionless variables for the energy generation rate and lum...

John F. Doorish

1994-04-01T23:59:59.000Z

52

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

Broader source: Energy.gov [DOE]

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

53

Investigation of the effects of heating rate on coking of shale during retorting  

SciTech Connect (OSTI)

The retorting of oil shale distributes organic carbon among three possible products: the liquid product, the noncondensible product, and the residual carbon (coke). The production of coke is detrimental because of the economic effects caused by the loss of organic carbon to this relatively intractable carbon form. Two reference oil shales, a Mahogany zone, Parachute Creek Member, Green River Formation oil shale from Colorado and a Clegg Creek Member, New Albany oil shale from Kentucky, were studied to evaluate the conditions that affect coke production during retorting. The variable that was studied in these experiments was the heating rate during retorting because heating rate has been indicated to have a direct effect on coke production (Burnham and Clarkson 1980). The six heating rates investigated covered the range from 1 to 650/degree/C/h (1.8 to 1169/degree/F/h). The data collected during these experiments were evaluated statistically in order to identify trends. The data for the eastern reference oil shale indicated a decrease in coke formation with increases in the heating rate. The liquid and noncondensible product yields both increased with increasing heating rate. The distribution of products in relation to retort heating rate follows the model suggested by Burnham and Clarkson (1980). Coke production during the retorting of western reference oil shale was found to be constant in relation to heating rate. The liquid product yield increased with increasing heating rate but the trend could not be verified at the 95% confidence level. The coke production observed in these experiments does not follow the prediction of the model. This may indicate that coke formation occurs early in the retorting process and may be limited by the availability of organic materials that form coke. 6 refs., 10 tabs.

Guffey, F.D.; Hunter, D.E.

1988-02-01T23:59:59.000Z

54

Closed-form evaluation and approximation considerations of the non-resonant thermonuclear reaction rate  

Science Journals Connector (OSTI)

By use of a highly efficient theory of generalized hypergeometric functions, we show that the non-resonant thermonuclear reaction rate can be evaluated in closed...

H. J. Haubold; R. W. John

1981-04-01T23:59:59.000Z

55

Gas temperature profiles at different flow rates and heating rates suffice to estimate kinetic parameters for fluidised bed combustion  

SciTech Connect (OSTI)

Experimental work on estimation kinetic parameters for combustion was conducted in a bench-scale fluidised bed (FB: 105x200mm). Combustion medium was obtained by using an electrical heater immersed into the bed. The ratio of heating rate (kJ/s) to molar flow rate of air (mol/s) regulated by a rheostat so that the heat of combustion (kJ/mol) can be synthetically obtained by an electrical power supply for relevant O{sub 2}-feedstock concentration (C{sub 0}). O{sub 2}-restriction ratio ({beta}) was defined by the ratio of O{sub 2}-feedstock concentration to O{sub 2}-air concentration (C{sub O{sub 2}-AIR}) at prevailing heating rates. Compressed air at further atmospheric pressure ({approx_equal}102.7kPa) entered the bed that was alumina particles (250{mu}m). Experiments were carried out at different gas flow rates and heating rates. FB was operated with a single charge of (1300g) particles for obtaining the T/T{sub 0} curves, and than C/C{sub 0} curves. The mathematical relationships between temperature (T) and conversion ratio (X) were expressed by combining total energy balance and mass balance in FB. Observed surface reaction rate constants (k{sub S}) was obtained from the combined balances and proposed model was also tested for these kinetic parameters (frequency factor: k{sub 0}, activation energy: E{sub A}, and reaction order: n) obtained from air temperature measurements. It was found that the model curves allow a good description of the experimental data. Thus, reaction rate for combustion was sufficiently expressed. (author)

Suyadal, Y. [Faculty of Engineering, Department of Chemical Engineering, Ankara University, 06100-Tandogan, Ankara (Turkey)

2006-07-15T23:59:59.000Z

56

Carbonization of Coal Effects of Variation of Rate of Heating during the Carbonization of a Typical Coking Coal  

Science Journals Connector (OSTI)

Carbonization of Coal Effects of Variation of Rate of Heating during the Carbonization of a Typical Coking Coal ...

William B. Warren

1935-01-01T23:59:59.000Z

57

Carbonization of Coal Evaluation of Effects of Rate of Heating and of Maximum Temperature on Pyrolysis of a Coking Coal  

Science Journals Connector (OSTI)

Carbonization of Coal Evaluation of Effects of Rate of Heating and of Maximum Temperature on Pyrolysis of a Coking Coal ...

William B. Warren

1935-01-01T23:59:59.000Z

58

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

SciTech Connect (OSTI)

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.

Mamum, Md Abdullah A. [Old Dominion Univ., Norfolk, VA (United States); Elmustafa, Abdelmageed A, [Old Dominion Univ., Norfolk, VA (United States); Stutzman, Marcy L. [JLAB, Newport News, VA (United States); Adderley, Philip A. [JLAB, Newport News, VA (United States); Poelker, Matthew [JLAB, Newport News, VA (United States)

2014-03-01T23:59:59.000Z

59

Heating rates in collisionally opaque alkali-metal atom traps: Role of secondary collisions  

Science Journals Connector (OSTI)

Grazing collisions with background gas are the major cause of trap loss and trap heating in atom traps. To first order, these effects do not depend on the trap density. In collisionally opaque trapped atom clouds, however, scattered atoms with an energy E larger than the effective trap depth Eeff, which are destined to escape from the atom cloud, will have a finite probability for a secondary collision. This results in a contribution to the heating rate that depends on the column density ?nl? of the trapped atoms, i.e., the product of density and characteristic size of the trap. For alkali-metal atom traps, secondary collisions are quite important due to the strong long-range interaction with like atoms. We derive a simple analytical expression for the secondary heating rate, showing a dependency proportional to ?nl??Eeff1/2. When extrapolating to a vanishing column density, only primary collisions with the background gas will contribute to the heating rate. This contribution is rather small, due to the weak long-range interaction of the usual background gas species in an ultrahigh-vacuum system—He, Ne, or Ar—with the trapped alkali-metal atoms. We conclude that the transition between trap-loss collisions and heating collisions is determined by a cutoff energy 200??K<~Eeff<~400??K, much smaller than the actual trap depth E in most magnetic traps. Atoms with an energy Eeffheating rates for the alkali-metal atoms Li through Cs as a function of the effective trap depth, the column density of the trap, and the species in the background gas. The predictions of our model are in good agreement with the experimental data of Myatt for heating rates in high-density 87Rb-atom magnetic traps at JILA, including the effect of the rf shield and the composition of the background gas. It is shown that collisions with atoms from the Oort cloud also contribute to the heating rate. For 85Rb the calculated heating rate is below the experimentally observed value at JILA, supporting the idea that inelastic collisions in the trap are the major source of heating.

H. C. W. Beijerinck

2000-11-15T23:59:59.000Z

60

Photo-heating and supernova feedback amplify each other's effect on the cosmic star formation rate  

E-Print Network [OSTI]

Photo-heating associated with reionisation and kinetic feedback from core-collapse supernovae have previously been shown to suppress the high-redshift cosmic star formation rate. Here we investigate the interplay between photo-heating and supernova feedback using a set of cosmological, smoothed particle hydrodynamics simulations. We show that photo-heating and supernova feedback mutually amplify each other's ability to suppress the star formation rate. Our results demonstrate the importance of the simultaneous, non-independent inclusion of these two processes in models of galaxy formation to estimate the strength of the total negative feedback they exert. They may therefore be of particular relevance to semi-analytic models in which the effects of photo-heating and supernova feedback are implicitly assumed to act independently of each other.

Andreas H. Pawlik; Joop Schaye

2008-12-15T23:59:59.000Z

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

:MEASUREMENTS OF ELECTRON CYCLOlRON HEATING RATES J. D. Barter, J. C. Sprott, K. L. Wong  

E-Print Network [OSTI]

53706 ABSTRACT Electron cyclotron heating rates have been measured for plasmas in a toroidal octupole Energy Corrrrnission. #12;2 Electron cyclotron heating has been a standard technique for producing hot:MEASUREMENTS OF ELECTRON CYCLOlRON HEATING RATES by J. D. Barter, J. C. Sprott, K. L. Wong Jillle

Sprott, Julien Clinton

62

Heat Balance Analysis to Validate the Heat Dissipation Rate of a Man-Made Lake as a Heat Rejection  

E-Print Network [OSTI]

. In addition, the analysis is to identify the most dominant variables for enhancing the lake dissipation rate and hence provide cost-effective measures to enhance the power plant efficiency. The case study power plant has 900 MW of power capacity with five...

Song, L.; Hayes, T.; Dawson, M.

2011-01-01T23:59:59.000Z

63

Heat-rate improvements obtained by retubing condensers with new, enhanced tube types  

SciTech Connect (OSTI)

Significant fuel savings can be achieved at power plants by retubing the condensers with enhanced tubes. Because of the higher overall heat-transfer coefficient, the exhaust steam is condensed at a lower pressure and the plant efficiency is therefore increased or plant heat rate is reduced. Only the spirally indented type of enhanced tube is currently being used in the U.S. and most other countries; however, different types of enhanced tubes have been proposed for power-plant condensers, each with their own set of attributes. This paper determines what attributes and their magnitudes of enhanced tubes lead to the most energy savings as measured by reduction of the plant heat rate. The particular attributes considered are the inside and outside enhancement levels, the inside efficiency index (inside enhancement level divided by pressure-drop increase), and the enhanced-tube fouling-rate multiplier. Two particular condensers were selected because all necessary information were known from previous heat-rate studies such as the condenser geometry, the circulating-water pump and system information, and the low-pressure turbine characteristics. These are {open_quotes}real-world{close_quotes} condensers and therefore the finding will be representative for many other condenser-retubing applications. However, the authors strongly recommend that an economic evaluation be performed at each site to determine the energy savings and payback time. This generic investigation showed that the outside enhancement level is the most important attribute, and a value of about 1.5 can lead to heat-rate savings of about 20 to 40 Btu/kW-hr. Increasing the inside enhancement is less effective because of the increased pressure drop that leads to a reduction of the coolant flow rate and velocity.

Rabas, T.J. [Argonne National Lab., IL (United States); Taborek, J. [Consulting Services, Virginia Beach, VA (United States)

1995-01-01T23:59:59.000Z

64

Heat-affected zone and ablation rate of copper ablated with femtosecond laser  

SciTech Connect (OSTI)

We describe the experimental and molecular dynamics simulation study of crystalline copper (Cu) ablation using femtosecond lasers. This study is focused on the heat-affected zone after femtosecond laser ablation and the laser ablation rate. As a result of the x-ray diffraction measurement on the ablated surface, the crystallinity of the surface is partially changed from a crystal structure into an amorphous one. At the laser fluences below the ablation threshold, the entire laser energy coupled to the Cu target is absorbed, while during the fluence regime over the threshold fluence, the ablation rate depends on the absorption coefficient, and the residual energy which is not used for the ablation, is left in the Cu substrate. The heat-affected zone at the fluences below the threshold is estimated to be greater than that over the threshold fluence. In addition, the laser ablation of Cu is theoretically investigated by a two-temperature model and molecular dynamics (MD) simulation to explain the heat-affected zone and ablation rate. The MD simulation takes into account the electron temperature and thermal diffusion length calculated by the two-temperature model. Variation in the lattice temperature with time and depth is calculated by the MD simulation coupled with the two-temperature model. The experimental ablation rate and the heat-affected zone are theoretically well explained.

Hirayama, Yoichi; Obara, Minoru [Department of Electronics and Electrical Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan)

2005-03-15T23:59:59.000Z

65

Development of an On-Line Expert System: Heat Rate Degradation Expert System Advisor  

E-Print Network [OSTI]

An on-line expert system for fossil-fueled power plants, the "Heat Rate Degradation Expert System Advisor," is being developed. This expert system will operate on a microcomputer and will interface with existing plant data acquisition and/or thermal...

Sopocy, D. M.; Henry, R. E.; Gehl, S.; Divakaruni, S. M.

66

Particle loading rates for HVAC filters, heat exchangers, and ducts Nomenclature  

E-Print Network [OSTI]

Particle loading rates for HVAC filters, heat exchangers, and ducts Nomenclature Afl surface area of floor (m2 ) bf fraction of bypass flow around the filter (dimensionless) Cout outdoor concentration on the filter per volume of air (mg/lm m3 ) Mf,tot total mass deposited on the filter per month of operation (g

Siegel, Jeffrey

67

Melting processes of oligomeric ? and ? isotactic polypropylene crystals at ultrafast heating rates  

SciTech Connect (OSTI)

The melting behaviors of ? (stable) and ? (metastable) isotactic polypropylene (iPP) crystals at ultrafast heating rates are simulated with atomistic molecular dynamics method. Quantitative information about the melting processes of ?- and ?-iPP crystals at atomistic level is achieved. The result shows that the melting process starts from the interfaces of lamellar crystal through random dislocation of iPP chains along the perpendicular direction of lamellar crystal structure. In the melting process, the lamellar crystal gradually expands but the corresponding thickness decreases. The analysis shows that the system expansion lags behind the crystallinity decreasing and the lagging extents for ?- and ?-iPP are significantly different. The apparent melting points of ?- and ?-iPP crystals rise with the increase of the heating rate and lamellar crystal thickness. The apparent melting point of ?-iPP crystal is always higher than that of ?-iPP at differently heating rates. Applying the Gibbs-Thomson rule and the scaling property of the melting kinetics, the equilibrium melting points of perfect ?- and ?-iPP crystals are finally predicted and it shows a good agreement with experimental result.

Ji, Xiaojing [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China)] [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); He, Xuehao, E-mail: xhhe@tju.edu.cn, E-mail: scjiang@tju.edu.cn [Department of Chemistry, School of Science, Tianjin University, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072 (China)] [Department of Chemistry, School of Science, Tianjin University, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072 (China); Jiang, Shichun, E-mail: xhhe@tju.edu.cn, E-mail: scjiang@tju.edu.cn [School of Material, Tianjin University, Tianjin 300072 (China)] [School of Material, Tianjin University, Tianjin 300072 (China)

2014-02-07T23:59:59.000Z

68

Electric field noise above surfaces: a model for heating rate scaling law in ion traps  

E-Print Network [OSTI]

We present a model for the scaling laws of the electric field noise spectral density as a function of the distance, $d$, above a conducting surface. Our analytical approach models the patch potentials by introducing a correlation length, $\\zeta$, of the electric potential on the surface. The predicted scaling laws are in excellent agreement with two different classes of experiments (cold trapped ions and cantilevers), that span at least four orders of magnitude of $d$. According to this model, heating rate in miniature ion traps could be greatly reduced by proper material engineering.

Romain Dubessy; Thomas Coudreau; Luca Guidoni

2008-12-17T23:59:59.000Z

69

Trade-offs between NO{sub x} heat rate and opacity at Morgantown Unit 2  

SciTech Connect (OSTI)

In work carried out at Morgantown Unit 2, PEPCO and Lehigh University developed techniques for optimizing the operation of an ABB-CE LNCFS III low NO{sub x} firing system. Because of marginal ESP capacity, the ability to reduce NO{sub x} is limited by opacity excursions at this unit. Using a parametric boiler testing approach, and guided by neural network techniques for analysis of the data, control settings were identified which minimize the full load heat rate as a function of the target NO{sub x} level, subject to a stack opacity constraint.

D`Agostini, M.; Walsh, R.; Eskenazi, D.; Levy, E. [Lehigh Univ., Bethlehem, PA (United States)] [and others

1996-05-01T23:59:59.000Z

70

Measuring the shock-heating rate in the winds of O stars using X-ray line spectra  

Science Journals Connector (OSTI)

......College, Department of Physics and Astronomy, Swarthmore...Iowa, Department of Physics and Astronomy, Iowa...Technology, Department of Physics and Space Sciences...determine the shock-heating rate due to instabilities...plasma systematically passes through the temperature......

David H. Cohen; Zequn Li; Kenneth G. Gayley; Stanley P. Owocki; Jon O. Sundqvist; Véronique Petit; Maurice A. Leutenegger

2014-01-01T23:59:59.000Z

71

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 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. A. Ferrare National Aeronautics and Space Administration Langley Research Center Hampton, Virginia R. T. Cederwall and S. C. Xie Los Alamos National Laboratory Los Alamos, New Mexico J. A. Ogren National Oceanic and Atmospheric Administration

72

Expert Meeting Report: Exploring the Disconnect Between Rated and Field Performance of Water Heating Systems  

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

Exploring the Disconnect Exploring the Disconnect Between Rated and Field Performance of Water Heating Systems M. Hoeschele and E. Weitzel Alliance for Residential Building Innovation (ARBI) May 2013 NOTICE This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, subcontractors, or affiliated partners makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark,

73

Spectral effects on the transmittance, solar heat gain, and performance rating of glazing systems  

Science Journals Connector (OSTI)

This study investigates the potential changes in Solar Heat Gain Coefficient (SHGC) and Visible Transmittance (VT) ratings of vertical or tilted glazing systems that would result from a deliberate change in the reference spectrum used as Spectral Weighting Function (SWF). This SWF is necessary to evaluate broadband-average optical properties from their spectral values, and obtain the desired rating of such bulk properties. The \\{SWFs\\} currently specified by rating institutions in Europe and North America for SHGC and VT are now outdated, and their inadequacies are discussed. Six potential replacements, which have been recently adopted by ASTM are described, including three direct irradiance spectra and three global irradiance spectrum incident on tilted surfaces of various tilts (20°, 37° and 90°). Some of these spectra have been tailored for use in building energy applications, including Building-Integrated Photovoltaics (BIPV). The effect of tilt on the U-factor and hence SHGC of glazing systems used for skylights on roofs is discussed, using a representative dataset of 37 glazing system specimens. The spectral effects on SHGC induced by a change in the current North American SWF are also obtained for this dataset, and show small to moderate deviations from current ratings (?2% to +7% for windows, and ?3% to +11% for skylights). The variations in VT are within ±2% for most glazing systems. To remove the current inconsistency in the \\{SWFs\\} used for SHGC and VT, it is recommended that a single SWF be used for both properties. For improved accuracy and reliance on active standards, it is also recommended that the SWF for SHGC and VT be either one of the two recent ASTM G197-08 global irradiance spectra, depending on application (incidence on a vertical surface for window applications, and incidence on a 20°-tilted surface for skylight applications). No change in colorimetric calculations (based on the D65 illuminant) is recommended, however.

Christian A. Gueymard; William C. duPont

2009-01-01T23:59:59.000Z

74

Coal plasticity at high heating rates and temperatures. Final technical progress report  

SciTech Connect (OSTI)

Plastic coals are important feedstocks in coke manufacture, coal liquefaction, gasification, and combustion. During these processes, the thermoplastic behavior of these coals is also important since it may contribute to desirable or undesirable characteristics. For example, during liquefaction, the plastic behavior is desired since it leads to liquid-liquid reactions which are faster than solid-liquid reactions. During gasification, the elastic behavior is undesired since it leads to caking and agglomeration of coal particles which result in bed bogging in fixed or fluidized bed gasifiers. The plastic behavior of different coals was studied using a fast-response plastometer. A modified plastometer was used to measure the torque required to turn at constant angular speed a cone-shaped disk embedded in a thin layer of coal. The coal particles were packed between two metal plates which are heated electrically. Heating rates, final temperatures, pressures, and durations of experiment ranged from 200--800 K/s, 700--1300 K, vacuum-50 atm helium, and 0--40 s, respectively. The apparent viscosity of the molten coal was calculated from the measured torque using the governing equation of the cone-and-plate viscometer. Using a concentrated suspension model, the molten coal`s apparent viscosity was related to the quantity of the liquid metaplast present during pyrolysis. Seven coals from Argonne National Laboratory Premium Coal Sample Bank were studied. Five bituminous coals, from high-volatile to low-volatile bituminous, were found to have very good plastic behavior. Coal type strongly affects the magnitude and duration of plasticity. Hvb coals were most plastic. Mvb and lvb coals, though the maximum plasticity and plastic period were less. Low rank coals such as subbituminous and lignite did not exhibit any plasticity in the present studies. Coal plasticity is moderately well correlated with simple indices of coal type such as the elemental C,O, and H contents.

Gerjarusak, S.; Peters, W.A.; Howard, J.B.

1995-05-01T23:59:59.000Z

75

Estimation of Rate of Heat Release by Means of Oxygen Consumption Measurements  

E-Print Network [OSTI]

the heat release of combustible wall linings during full-scale room fire tests, William Parker, Huggett to the release of heat, the combustion process consumes oxygen. As part of his work on the ASTM E 84 tunnel test released per unit mass of material consumed (i.e., the specific heat of combustion), varied greatly

Womeldorf, Carole

76

Differential rates for district heating and the influence on the optimal retrofit strategy for multi-family buildings  

Science Journals Connector (OSTI)

When renovating existing multi-family buildings it is very important to implement the best retrofit strategy possible in order to minimize the remaining life-cycle cost for the building. If the building is heated with district heating this strategy of course changes due to the energy rate used by the utility. It is also very important for the utility that the consumer is encouraged to save energy when there is a need for it, i.e. during peak load conditions. Our paper shows that an accurate cost differential rate provides all these facilities.

Stig-Inge Gustafsson; Björn G. Karlsson; Bertil H. Sjöholm

1987-01-01T23:59:59.000Z

77

Shut-down dose rate analyses for the ITER electron cyclotron-heating upper launcher  

Science Journals Connector (OSTI)

Abstract The electron cyclotron resonance heating upper launcher (ECHUL) is going to be installed in the upper port of the ITER tokamak thermonuclear fusion reactor for plasma mode stabilization (neoclassical tearing modes and the sawtooth instability). The paper reports the latest neutronic modeling and analyses which have been performed for the ITER reference front steering launcher design. It focuses on the port accessibility after reactor shut-down for which dose rate (SDDR) distributions on a fine regular mesh grid were calculated. The results are compared to those obtained for the ITER Dummy Upper Port. The calculations showed that the heterogeneous ECHUL design gives rise to enhanced radiation streaming as compared to the homogenous dummy upper port. Therefore the used launcher geometry was upgraded to a more recent development stage. The inter-comparison shows a significant improvement of the launchers shielding properties but also the necessity to further upgrade the shielding performance. Furthermore, the analysis for the homogenous dummy upper port, which represents optimal shielding inside the launcher, demonstrates that the shielding upgrade also needs to include the launcher's environment.

Bastian Weinhorst; Arkady Serikov; Ulrich Fischer; Lei Lu; Peter Spaeh; Dirk Strauss

2014-01-01T23:59:59.000Z

78

Fuel consumption rate in a heat-powered unit analyzed as a function of the temperature and consumption ratio of the air  

Science Journals Connector (OSTI)

An analysis of fuel consumption for a heat-powered unit in the ... of ceramic materials is given. The heat consumption rate is analyzed as a function of ... generating the working medium, and of the consumption r...

N. A. Tyutin

2006-01-01T23:59:59.000Z

79

Determination of size-specific U-factors and solar heat gain coefficients from rated values at established sizes -- A simplified approach  

SciTech Connect (OSTI)

Organizations such as the National Fenestration Rating Council (NFRC) in the United States and the Canadian Standards Association in Canada have done a vast amount of work to develop standardized procedures for rating the thermal performance of window systems. These procedures provide an excellent means of comparing one window product to another. One limitation to the use of the information produced in these rating procedures is that the data are produced through measurement or simulation for a fixed window size. To use these data in building energy computer simulations, the U-factor and solar heat gain coefficient (SHGC) data need to be available for the actual window sizes used in a building. The window labeling information provided through the window rating procedures in the US and Canada is not enough to calculate size-specific U-factor or SHGC values. Using minimal information that is provided from the rating procedures and making a few simplifying assumptions will allow for /an approximation of the size-specific U-factor and SHGC values. The work presented in this paper outlines a simplified approach to determining size-specific U-factor and SHGC values.

Baker, J.A. [WestLab, Waterloo, Ontario (Canada); Henry, R. [CANMET/Natural Resources, Ottawa, Ontario (Canada)

1997-12-31T23:59:59.000Z

80

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.

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Activation, Heating and Exposure Rates for Mo?99 Experiments with 25?Disk Targets  

SciTech Connect (OSTI)

An MCNPX model of the 25-disk target assembly inside the vacuum cube inside the shielded box was prepared. This was used to calculate heating and photon and neutron fluxes throughout the model. Production rates for photonuclear reaction products were calculated using the photon fluxes and ENDF/B-VII cross sections. Measured isomer to ground state yield ratios were used where available. Where not available the new correlation between spin deficit and isomer to ground state yield ratios presented at AccApp'11 was used. The photonuclear production rates and neutron fluxes were input to CINDER2008 for transmutation calculations. A cross section update file was used to supply (n,n') reactions missing from CINDER2008 libraries. Decay photon spectra produced by CINDER2008 were then used to calculate exposure rates using the MCNPX model. Two electron beam irradiations were evaluated. The first was for a thermal test at 15 MeV with 1300 {micro}A incident on one target end and the second was for a production test at 35 MeV with 350 {micro}A incident on both target ends (700 {micro}A total current on target). For the thermal test 1, 2, 3, 4, 5 and 6 h irradiation times were simulated, each followed by decay time steps out to 42 days. For the production test 6, 12, 18, 24, 30 and 36 h irradiation times were simulated followed by the same decay periods. For all simulations beam FWHMs in x and y were both assumed to be 6 mm. Simulations were run for Mo-100 enriched and natural Mo targets for both tests. It is planned that thermal test will be run for 4 h with natural target disks and production test will be run for 24 h with enriched target disks. Results for these two simulations only are presented in this report. Other results can be made available upon request. Post irradiation exposure rates were calculated at 30 cm distances from left, right, front and back of the following configurations: (1) Shielded box with everything in it (beam pipes, cooling pipes, vacuum cube, target housing weldment and target assembly), (2) Shielded box with everything in it except the target assembly, (3) Shielded box with nothing in it, (4) Target assembly taken outside of shielded box, (5) Target disks in cradle (target assembly with thermocouple weldment and flange removed), (6) Empty cradle, and (7) Target disks alone. Decay photon spectra from the CINDER2008 calculations were used as sources for the exposure rate calculations in the same model used for the flux calculations with beam on. As components were removed to simulate the seven cases considered the material compositions were changed to air and their respective sources were turned off. The MCNPX model geometry is plotted in Figure 1. The left and right detector locations for cases 1, 2 and 3 were 30 cm from the shielded box walls and 30 cm from the beam pipe openings in the left and right sides of the model (they are not in the beam line). A zoomed in plot of the target assembly alone is in Figure 2. Exposure rates for the seven cases are plotted as a function of time after irradiation in Figures 3, 4 and 5. To aid in comparison between the cases, all of these figures have been plotted using the same scale. Figures 3 and 4 are respectively the thermal and production test results for cases 1 through 6. Figure 5 includes case 7 results for both. Differences between cases 1 and 2 for both tests are not statistically significant showing that activation of components other than the target assembly, many of which are also shielding the target assembly, dominates exposure rates outside the shielded box. Case 3 shows the contribution from activation of the shield box itself. In front where shielded box wall is thickest box activation accounts for essentially all of the exposure rate outside. Differences between cases 4 and 5 are also minimal, showing that the contribution to target assembly exposure rates from the thermocouple flange and weldment are small compared to the target disks and cradle. From the numerical results the contribution is about 1%. Results for case 6, the cradle itself, are ini

Kelsey, Charles T. IV [Los Alamos National Laboratory

2012-05-09T23:59:59.000Z

82

forth through the heat exchangers, thereby phasing the rates at which heat is absorbed and rejected from  

E-Print Network [OSTI]

Conditions Charge Pressure (psia) Firing Rate (KBTUH) Frequency (Hz) Power Piston Stroke (in.) Displacer the earlier analysis; these results are shown in Fig. 4. Working Fluid Charge Pressure (psia) Power Level (k was measured as the total enthalpy gain of the refrigerant across the compres- sor. Table 2 shows the range

Oak Ridge National Laboratory

83

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

SciTech Connect (OSTI)

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.

Hufnagel, Todd C.

2014-06-09T23:59:59.000Z

84

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

E-Print Network [OSTI]

and future needs of the power industry follows. The discussion is restricted to steam turbine cycles of fossil or nuclear power plants, although some ECC's can be employed to a wider range of applications, such as analysis of different heat sources... and future needs of the power industry follows. The discussion is restricted to steam turbine cycles of fossil or nuclear power plants, although some ECC's can be employed to a wider range of applications, such as analysis of different heat sources...

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

1981-01-01T23:59:59.000Z

85

Heat Transfer Modeling and Use of Distributed Temperature Measurements to Predict Rate  

E-Print Network [OSTI]

to demonstrate the application of the methodology of rate estimation proposed. Fluid flow rates for steady and transient cases were successfully estimated within engineering accuracy for all three cases. In all three cases, in addition to the traditional downhole...

Hashmi, Gibran Mushtaq

2014-07-08T23:59:59.000Z

86

RATES  

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

Planning & Projects Planning & Projects Power Marketing Rates You are here: SN Home page > Power Marketing > RATES Rates and Repayment Services Rates Current Rates Power Revenue Requirement Worksheet (FY 2014) (Oct 2013 - Sep 2014) (PDF - 30K) PRR Notification Letter (Sep 27, 2013) (PDF - 959K) FY 2012 FP% True-Up Calculations(PDF - 387K) Variable Resource Scheduling Charge FY12-FY16 (October 1, 2012) PRR Forecast FY14-FY17 (May 23, 2013) (PDF - 100K) Forecasted Transmission Rates (May 2013) (PDF - 164K) Past Rates 2013 2012 2011 2010 2009 Historical CVP Transmission Rates (April 2013) (PDF - 287K) Rate Schedules Power - CV-F13 - CPP-2 Transmission - CV-T3 - CV-NWT5 - PACI-T3 - COTP-T3 - CV-TPT7 - CV-UUP1 Ancillary - CV-RFS4 - CV-SPR4 - CV-SUR4 - CV-EID4 - CV-GID1 Federal Register Notices - CVP, COTP and PACI

87

RATES  

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

Marketing > RATES Marketing > RATES RATES Current Rates Past Rates 2006 2007 2008 2009 2010 2011 2012 Rates Schedules Power CV-F13 CPP-2 Transmissions CV-T3 CV-NWT5 PACI-T3 COTP-T3 CV-TPT7 CV-UUP1 Ancillary CV-RFS4 CV-SPR4 CV-SUR4 CV-EID4 CV-GID1 Future and Other Rates SNR Variable Resource Scheduling Charge FY12-FY16 (October 1, 2012) SNR Rates Process Calendar (PDF - 171K) Procedures Informal Process Transmission Action Items List (PDF - 144K) Power Action Item List updated on 4-27-10 (PDF - 155K) Power Action Item List (Quick links to relevant documents) Formal Process Rates Brochure (01/11/2011) (PDF - 900K) Appendix A - Federal Register Notice (01/03/2011) (PDF - 8000K) Appendix B - Central Valley Project Power Repayment Study (PDF - 22,322K) Appendix C - Development of the CVP Cost of Service Study (PDF - 2038K)

88

RATES  

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

RATES RATES Rates Document Library SNR Rates Process Calendar (PDF - 171K) Procedures Informal Process Transmission Action Items List (PDF - 144K) Power Action Item List updated on 4-27-10 (PDF - 155K) Power Action Item List (Quick links to relevant documents) Formal Process Rates Brochure (01/11/2011) (PDF - 900K) Appendix A - Federal Register Notice (01/03/2011) (PDF - 8000K) Appendix B - Central Valley Project Power Repayment Study (PDF - 22,322K) Appendix C - Development of the CVP Cost of Service Study (PDF - 2038K) Appendix D - Western Transmission System Facilities Map (PDF - 274K) Appendix E - Estimated FY12 FP and BR Customer (PDF - 1144K) Appendix F - Forecasted Replacements and Additions FY11 - FY16 (PDF - 491K) Appendix G - Definitions (PDF - 1758K) Appendix H - Acronyms (PDF - 720K)

89

Integrated flue gas treatment for simulataneous emission control and heat rate improvement - demonstration project at Ravenswood  

SciTech Connect (OSTI)

Results are presented for electric-utility, residual-oil fired, field demonstration testing of advanced-design, heat-recovery type, flue gas sub-coolers that incorporate sulfite-alkali-based wet scrubbing for efficient removal of volatile and semi-volatile trace elements, sub-micron solid particulate matter, SO{sub 2} and SO{sub 3}. By innovative adaptation of wet collector system operation with methanol injection into the rear boiler cavity to convert flue-gas NO to No{sub 2}, simultaneous removal of NO{sub x} is also achieved. The focus of this integrated flue gas treatment (IFGT) technology development and demonstration-scale, continuous performance testing is an upward-gas-flow, indirectly water-cooled, condensing heat exchanger fitted with acid-proof, teflon-covered tubes and tubesheets and that provides a unique condensing (non-evaporative) wet-scrubbing mode to address air toxics control objectives of new Clean Air Act, Title III. Advantageous trace-metal condensation/nucleation/agglomeration along with substantially enhanced boiler efficiency is accomplished in the IFGT system by use of boiler makeup water as a heat sink in indirectly cooling boiler flue gas to a near-ambient-temperature, low-absolute-humidity, water-saturated state. Moreover, unique, innocuous, stack systems design encountered with conventional high-humidity, wet-scrubber operations. The mechanical design of this advanced flue-gas cooling/scrubbing equipment is based on more than ten years of commercial application of such units is downward-gas-flow design/operation for energy recovery, e.g. in preheating of makeup water, in residual-oil and natural-gas fired boiler operations.

Heaphy, J.; Carbonara, J.; Cressner, A. [Consolidated Edison Company, New York, NY (United States)] [and others

1995-06-01T23:59:59.000Z

90

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

SciTech Connect (OSTI)

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.

George A. Young; Nathan Lewis

2003-04-05T23:59:59.000Z

91

Heating, Current Drive, Operations and Diagnostics Issues Understand implications of reduced repetition rate, is it adequate for the  

E-Print Network [OSTI]

Heating, Current Drive, Operations and Diagnostics Issues Operations · Understand implications of ECRH to improve startup. Heating · ICRF is the base line heating system, compare with NBI and ECRH withstand the anticipated heat loads? Diagnostics · Capability of beam diagnostics for J(r), E(r), etc

92

Sideband cooling an ion to the quantum ground state in a Penning trap with very low heating rate  

E-Print Network [OSTI]

We report the laser cooling of a single $^{40}\\text{Ca}^+$ ion in a Penning trap to the motional ground state in one dimension. Cooling is performed in the strong binding limit on the 729-nm electric quadrupole $S_{1/2}\\leftrightarrow D_{5/2}$ transition, broadened by a quench laser coupling the $D_{5/2}$ and $P_{3/2}$ levels. We find the final phonon number to be $\\bar{n}=0.014\\pm0.009$. We measure the heating rate of the trap to be very low with $\\dot{\\bar{n}}=2.5\\pm 0.3\\textrm{s}^{-1}$ and a scaled spectral noise density of $\\omega S_{E}(\\omega)\\sim1.6^{-8}\\textrm{V}^2\\textrm{m}^{-2}\\textrm{Hz}^{-1}\\textrm{s}^{-1}$, which is consistent with the large ion-electrode distance. We perform Rabi oscillations on the sideband-cooled ion and observe a coherence time of $0.7\\pm 0.1\\textrm{ms}$, noting that the practical performance is currently limited by the intensity noise of the probe laser.

J. F. Goodwin; G. Stutter; R. C. Thompson; D. M. Segal

2014-07-23T23:59:59.000Z

93

Diabatic Heating and Cooling Rates Derived from In Situ Microphysics Measurements: A Case Study of a Wintertime U.K. Cold Front  

Science Journals Connector (OSTI)

In situ measurements associated with the passage of a kata cold front over the United Kingdom on 29 November 2011 are used to initialize a Lagrangian parcel model for the purpose of calculating rates of diabatic heating and cooling associated with ...

C. Dearden; P. J. Connolly; G. Lloyd; J. Crosier; K. N. Bower; T. W. Choularton; G. Vaughan

2014-09-01T23:59:59.000Z

94

Mechanism of heat-modification inside a glass after irradiation with high-repetition rate femtosecond laser pulses  

SciTech Connect (OSTI)

Accumulation of thermal energies by highly repeated irradiation of femtosecond laser pulses inside a glass induces the heat-modification whose volume is much larger than that of the photoexcited region. It has been proposed that the heat-modification occurs in the region in which the temperature had overcome a threshold temperature during exposure of laser pulses. In order to understand the mechanism of the heat-modification, we investigated the temperature distribution during laser exposure and the threshold temperature by analyzing the volume of the modification based on a thermal diffusion model. We found that the threshold temperature becomes lower with increasing laser exposure time. The dependence of the threshold temperature on the laser exposure time was explained by the deformation mechanism based on the temperature-dependent viscosity and viscoelastic behavior of a glass under a stress loading by thermal expansion. The deformation mechanism also could simulate a tear-drop shape of a heat-modification by simultaneous double-beams' irradiation and the distribution of birefringence in a heat-modification. The mechanism proposed in this study means that the temperature-dependence of the viscosity of a glass should be essential for predicting and controlling the heat-modification.

Shimizu, Masahiro; Miura, Kiyotaka; Hirao, Kazuyuki [Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510 (Japan); Sakakura, Masaaki; Shimotsuma, Yasuhiko [Innovative Collaboration Center, Kyoto University, Kyoto 615-8520 (Japan); Ohnishi, Masatoshi [Qualtec Co., Ltd., 4-230 Sanbocho, Sakai-ku, Sakai-shi, Osaka 590-0906 (Japan); Nakaya, Takayuki [NJC Institute of Technology, Namiki Precision Jewel Co., Ltd., 8-22 Shinden 3-Chome, Adachi-ku, Tokyo 123-8511 (Japan)

2010-10-15T23:59:59.000Z

95

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

E-Print Network [OSTI]

DETERMINATION OF THERMAL-DEGRADATION RATES OF SOME CANDIDATE RANKINE-CYCLE ORGANIC WORKING FLUIDS FOR CONVERSION OF INDUSTRIAL WASTE HEAT INTO POWER Mohan L. Jain, Jack Demirgian, John L. Krazinski, and H. Bushby Argonne National Laboratory..., Argonne, Illinois Howard Mattes and John Purcell U.S. Department of Energy ABSTRACT Serious concerns over the long-term thermal In a previous study [1] based on systems stability of organic working fluids and its effect analysis and covering...

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

1984-01-01T23:59:59.000Z

96

Four-mode Bose-Hubbard model with two greatly differing tunneling rates as a model for the Josephson oscillation of heat  

SciTech Connect (OSTI)

As a model for mesoscopic quantum systems in thermal contact, we consider a four-mode Bose-Hubbard model with two greatly differing tunneling rates. By a series of Holstein-Primakoff transformations, we show that the low-frequency dynamics of this system consists in general of two slow Josephson oscillations, rather than the single slow mode predicted by linear Bogoliubov theory. We identify the second slow Josephson oscillation as a heat exchange mode analogous to second sound.

Strzys, M. P.; Anglin, J. R. [OPTIMAS Research Center and Fachbereich Physik, Technische Universitaet Kaiserslautern, D-67653 Kaiserslautern (Germany)

2010-04-15T23:59:59.000Z

97

7-88 A geothermal power plant uses geothermal liquid water at 160C at a specified rate as the heat source. The actual and maximum possible thermal efficiencies and the rate of heat rejected from this power plant  

E-Print Network [OSTI]

and potential energy changes are zero. 3 Steam properties are used for geothermal water. Properties Using7-31 7-88 A geothermal power plant uses geothermal liquid water at 160ºC at a specified rate saturated liquid properties, the source and the sink state enthalpies of geothermal water are (Table A-4) k

Bahrami, Majid

98

Assessment of Uncertainty in Cloud Radiative Effects and Heating Rates through Retrieval Algorithm Differences: Analysis using 3-years of ARM data at Darwin, Australia  

SciTech Connect (OSTI)

Ground-based radar and lidar observations obtained at the Department of Energy’s Atmospheric Radiation Measurement Program’s Tropical Western Pacific site located in Darwin, Australia are used to retrieve ice cloud properties in anvil and cirrus clouds. Cloud microphysical properties derived from four different retrieval algorithms (two radar-lidar and two radar only algorithms) are compared by examining mean profiles and probability density functions of effective radius (Re), ice water content (IWC), extinction, ice number concentration, ice crystal fall speed, and vertical air velocity. Retrieval algorithm uncertainty is quantified using radiative flux closure exercises. The effect of uncertainty in retrieved quantities on the cloud radiative effect and radiative heating rates are presented. Our analysis shows that IWC compares well among algorithms, but Re shows significant discrepancies, which is attributed primarily to assumptions of particle shape. Uncertainty in Re and IWC translates into sometimes-large differences in cloud radiative effect (CRE) though the majority of cases have a CRE difference of roughly 10 W m-2 on average. These differences, which we believe are primarily driven by the uncertainty in Re, can cause up to 2 K/day difference in the radiative heating rates between algorithms.

Comstock, Jennifer M.; Protat, Alain; McFarlane, Sally A.; Delanoe, Julien; Deng, Min

2013-05-22T23:59:59.000Z

99

Microwave heating for adsorbents regeneration and oil sands coke activation.  

E-Print Network [OSTI]

??Microwave heating has unique advantages compared to convection-radiation heating methods including fast heating rate and selective heating of objects. This thesis studied two applications of… (more)

Chen, Heng

2010-01-01T23:59:59.000Z

100

Including radiative heat transfer and reaction quenching in modeling a Claus plant waste heat boiler  

SciTech Connect (OSTI)

Due to increasingly stringent sulfur emission regulations, improvements are necessary in the modified Claus process. A recently proposed model by Nasato et al. for the Claus plant waste heat boiler (WHB) is improved by including radiative heat transfer, which yields significant changes in the predicted heat flux and the temperature profile along the WHB tube, leading to a faster quenching of chemical reactions. For the WHB considered, radiation accounts for approximately 20% of the heat transferred by convection alone. More importantly, operating the WHB at a higher gas mass flux is shown to enhance reaction quenching, resulting in a doubling of the predicted hydrogen flow rate. This increase in hydrogen flow rate is sufficient to completely meet the hydrogen requirement of the H[sub 2]S recovery process considered, which would eliminate the need for a hydrogen plant.

Karan, K.; Mehrotra, A.K.; Behie, L.A. (Univ. of Calgary, Alberta (Canada). Dept. of Chemical and Petroleum Engineering)

1994-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Fast Approximate Convex Decomposition  

E-Print Network [OSTI]

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

Ghosh, Mukulika

2012-10-19T23:59:59.000Z

102

A comparison of approximate models for radiation in gas turbines  

Science Journals Connector (OSTI)

Approximate equations for radiative heat transfer equations coupled to an equation for the temperature are stated and a comparative numerical study of the different approximations is given. The approximation methods considered here range from moment methods to simplified PN-approximations. Numerical experiments and comparisons in different space dimensions and for various physical situations are presented.

M. Frank; M. Seaid; A. Klar; R. Pinnau; G. Thommes; J. Janicka

2004-01-01T23:59:59.000Z

103

Domestic Heating and Thermal Insulation  

Science Journals Connector (OSTI)

... DIGEST 133 of the Building Research Station, entitled "Domestic Heating and Thermal Insulation" (Pp. 7. London : H.M. Stationery Office, 1960. 4insulation, the standard of heating, the ventilation-rate and the length of the heating season ...

1960-09-17T23:59:59.000Z

104

Tests of Monte Carlo Independent Column Approximation With a Mixed-Layer Ocean Model  

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

Tests of Monte Carlo Independent Column Tests of Monte Carlo Independent Column Approximation With a Mixed-Layer Ocean Model Petri Simo Järvenoja Heikki Järvinen Räisänen Finnish Meteorological Institute Figure 1. Root-mean-square sampling errors in local instant- aneous total (LW+SW) net flux at the surface and total radiative heating rate for the 1COL, CLDS, and REF approaches. Global rms values are given at the upper right hand corner of the plots. 1. Introduction The Monte Carlo Independent Column Approximation (McICA) separates the description of unresolved cloud structure from the radiative transfer solver very flexible ! unbiased with respect to ICA ! However, the radiative fluxes and heating rates contain conditional random errors ("McICA noise"). ? The topic of this poster: All previous tests of McICA

105

HEAT RECOVERY FROM WASTE WATER BY MEANS OF A RECUPERATIVE HEAT EXCHANGER AND A HEAT PUMP  

Science Journals Connector (OSTI)

ABSTRACT The useful heat of warm waste water is generally transferred to cold water using a recuperative heat exchanger. Depending on its design, the heat exchanger is able to utilise up to 90% of the waste heat potential available. The electric energy needed to operate such a system is more than compensated for by an approximately 50-fold gain of useful heat. To increase substantially the waste heat potential available and the amount of heat recovered, the system for recuperative heat exchange can be complemented by a heat pump. Such a heat recovery system on the basis of waste water is being operated in a public indoor swimming pool. Here the recuperative heat exchanger accounts for about 60%, the heat pump for about 40% of the toal heat reclaimed. The system consumes only 1 kWh of electric energy to supply 8 kWh of useful heat. In this way the useful heat of 8 kWh is compensated for by the low consumption of primary energy of 2.8 kWh. Due to the installation of an automatic cleaning device, the heat transfer surfaces on the waste water side avoid deposits so that the troublesome maintenance work required in other cases on the heat exchangers is not required. KEYWORDS Shower drain water, recuperative heat recovery, heat recovery by means of a heat pump, combination of both types of heat recovery, automatic cleaning device for the heat exchangers, ratio of useful heat supply vs. electric energy consumption, economic consideration.

K. Biasin; F.D. Heidt

1988-01-01T23:59:59.000Z

106

A correlated K-distribution model of the heating rates for H[sub 2]O and a molecular mixture in the 0-2500 cm[sup [minus]1] wavelength region in the atmosphere between 0 and 60 km  

SciTech Connect (OSTI)

For this report a prototype infrared radiative transfer model using a correlated k-distribution technique to calculate the transmission between atmospheric levels has been used to calculate the radiative fluxes and heating rates for H[sub 2]O and a mixture of the major molecular absorbers in the atmosphere between 0 and 60 km. The mixture consists of H[sub 2]O, CO[sub 2], O[sub 3], CH[sub 4], and N[sub 2]O. The wave number range considered is 0-2500 cm[sup [minus]1]. The use of the k-distribution method allows 25 cm[sup [minus]1] wave number bins to produce fluxes and heating rates which are within ten percent of the results of detailed line by line calculations.

Grossman, A S; Grant, K E

1992-11-16T23:59:59.000Z

107

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

SciTech Connect (OSTI)

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

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

2013-06-01T23:59:59.000Z

108

The Boussinesq approximation in rapidly rotating flows  

E-Print Network [OSTI]

In the classical formulation of the Boussinesq approximation centrifugal buoyancy effects related to differential rotation, as well as strong vortices in the flow, are neglected. However, these may play an important role in rapidly rotating flows, such as in astrophysical and geophysical applications, and also in turbulent convection. We here provide a straightforward approach resulting in a Boussinesq-type approximation that consistently accounts for centrifugal effects. We further compare our new approach to the classical one in fluid flows confined between two differentially heated and rotating cylinders. The results justify the need of using the proposed approximation in rapidly rotating flows.

Lopez, Jose M; Avila, Marc

2013-01-01T23:59:59.000Z

109

Analysis of the behavior of an experimental absorption heat transformer for water purification for different mass flux rates in the generator  

Science Journals Connector (OSTI)

In the present study, first and second laws of thermodynamics have been used to analyse the performance of an experimental absorption heat transformer for water purification. Irreversibilities, coefficients of performance (COP) and exergy coefficients of performance (ECOP) were determined as function of the mass flow of hot water supplied to the generator and as function of the overall thermal specific energy consumption (OSTEC) parameter defined in this paper. The results showed that the system irreversibilities increase meanwhile the coefficients of performance and the exergy coefficient of performance decrease with an increment of the mass flow of hot water supplied to the generator. Also it was shown that the system performance is better when the production of purified water increases due to the increment of the heat recycled to the generator and evaporator.

Armando Huicochea; Wilfrido Rivera; Hiram Martínez; Javier Siqueiros; Erasmo Cadenas

2013-01-01T23:59:59.000Z

110

Heat Transfer Enhancement in Thermoelectric Power Generation.  

E-Print Network [OSTI]

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

Hu, Shih-yung

2009-01-01T23:59:59.000Z

111

Heat Requirements of Buildings  

Science Journals Connector (OSTI)

... and Ventilating Engineers in a publication entitled “Recommendations for the Computation of Heat Requirements for Buildings” (Pp. iii+41. Is. 9d.) This comprises a section of the ... parts. That on temperature-rise and rates of change gives the recommended values applicable to buildings ranging alphabetically from aircraft sheds to warehouses. The design of heating and ventilating installations ...

1942-02-28T23:59:59.000Z

112

Geothermal heating from Pinkerton Hot Springs at Colorado Timberline Academy, Durango, Colorado. Final technical report  

SciTech Connect (OSTI)

The efforts to establish a greater pool of knowledge in the field of low temperature heat transfer for the application of geothermal spring waters to space heating are described. A comprehensive set of heat loss experiments involving passive radiant heating panels is conducted and the results presented in an easily interpretable form. Among the conclusions are the facts that heating a 65 to 70 F/sup 0/ space with 90 to 100 F/sup 0/ liquids is a practical aim. The results are compared with the much lower rates published in the American Society of Heating Refrigeration and Air Conditioning Engineers SYSTEMS, 1976. A heat exchange chamber consisting of a 1000 gallon three compartment, insulated and buried tank is constructed and a control and pumping building erected over the tank. The tank is intended to handle the flow of geothermal waters from Pinkerton Hot Springs at 50 GPM prior to the wasting of the spring water at a disposal location. Approximately 375,000 Btu per hour should be available for heating assuming a 15 F/sup 0/ drop in water temperature. A combination of the panel heat loss experiments, construction of the heat exchange devices and ongoing collection of heat loss numbers adds to the knowledge available to engineers in sizing low temperature heat systems, useful in both solar and geothermal applications where source temperature may be often below 110 F/sup 0/.

Allen, C.C.; Allen, R.W.; Beldock, J.

1981-11-08T23:59:59.000Z

113

Approximation Algorithms Tandy Warnow  

E-Print Network [OSTI]

size and 1 / . #12;Approximation algorithms for: Minimum Vertex Cover (finding a set of vertices-SAT 3-SAT DIR-HAM-CYCLEINDEPENDENT SET VERTEX COVER GRAPH 3-COLOR HAM-CYCLE TSP SUBSET-SUM SCHEDULINGPLANAR 3-COLOR SET COVER NP-Completeness by definition of NP-completeness #12;NP-hard Optimization

Warnow,Tandy

114

On the Oberbeck-Boussinesq approximation on unbounded domains  

E-Print Network [OSTI]

On the Oberbeck-Boussinesq approximation on unbounded domains Eduard Feireisl and Maria E. Schonbek Abstract We study the Oberbeck-Boussinesq approximation describing the mo- tion of an incompressible, heat that the total energy of any solution of the resulting Oberbeck-Boussinesq system tends to zero with growing time

Schonbek, Maria

115

Thermal single-well injection-withdrawal tracer tests for determining fracture-matrix heat transfer area  

E-Print Network [OSTI]

rates of rocks- to-fluid heat transfer, and thereby thesurface for heat transfer to injected fluids circulating influids, and thereby increase the overall rate of heat transfer

Pruess, K.

2011-01-01T23:59:59.000Z

116

Definition: Heat | Open Energy Information  

Open Energy Info (EERE)

Heat Heat Jump to: navigation, search Dictionary.png Heat Heat is the form of energy that is transferred between systems or objects with different temperatures (flowing from the high-temperature system to the low-temperature system). Also referred to as heat energy or thermal energy. Heat is typically measured in Btu, calories or joules. Heat flow, or the rate at which heat is transferred between systems, has the same units as power: energy per unit time (J/s).[1][2][3][4] View on Wikipedia Wikipedia Definition In physics and chemistry, heat is energy in transfer between a system and its surroundings other than by work or transfer of matter. The transfer can occur in two simple ways, conduction, and radiation, and in a more complicated way called convective circulation. Heat is not a property

117

Spring 2014 Heat Transfer -1  

E-Print Network [OSTI]

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

Virginia Tech

118

Geothermal Heat Pumps- Heating Mode  

Broader source: Energy.gov [DOE]

In winter, fluid passing through this vertical, closed loop system is warmed by the heat of the earth; this heat is then transferred to the building.

119

Cooling characteristics of ground source heat pump with heat exchange methods  

Science Journals Connector (OSTI)

Abstract The objective of this study is to investigate the influence of the cooling performance for a water-to-water ground source heat pump (GSHP) by using the counter flow and parallel flow methods. The GSHP uses R-410A as a refrigerant, and its main components are a scroll compressor, plate heat exchangers as a condenser, an evaporator, a thermostatic expansion valve, a receiver, and an inverter. Based on our modeling results, the heat transfer rate of the counter flow evaporator is higher than that of the parallel flow evaporator for a heat exchanger length greater than 0.42 m. The evaporator length of the GSHP used in this study was set to over 0.5 m. The performance of the water-to-water GSHP was measured by varying the compressor speed and source-side entering water temperature (EWT). The cooling capacity of the GSHP increased with increased compressor \\{RPMs\\} and source side EWT. Also, using the counter flow method, compared to the parallel flow method, improves the COP by approximately 5.9% for an ISO 13256-2 rated condition.

Ohkyung Kwon; KyungJin Bae; Chasik Park

2014-01-01T23:59:59.000Z

120

detonation rate  

Science Journals Connector (OSTI)

detonation rate, detonation velocity, velocity of detonation, V.O.D., detonating velocity, rate of detonation, detonating rate ? Detonationsgeschwindigkeit f

2014-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

The multiple absorption coefficient zonal method (MACZM), an efficient computational approach for the analysis of radiative heat transfer in multidimensional inhomogeneous nongray media  

E-Print Network [OSTI]

of Radiative Heat Transfer, the P-3 Approximation”, AIAAMedia”, Journal of Heat Transfer, Vol. 109, No. 3 (1987),Media”, Numerical Heat Transfer, Part B, Fundamentals, Vol.

Yuen, W W

2006-01-01T23:59:59.000Z

122

Hybrid Heat Pump Design and Application  

E-Print Network [OSTI]

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

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

123

Design Considerations for Industrial Heat Recovery Systems  

E-Print Network [OSTI]

in these high-quality waste heat streams, at today's oil prices, is approximately 12 billion dollars per year. Heat recovery is perhaps one of the largest energy conservation opportunities available to U. S. industries today. The author reviews basic heat...

Bywaters, R. P.

1979-01-01T23:59:59.000Z

124

Compare All CBECS Activities: District Heat Use  

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

District Heat Use 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 trillion Btu of district heat (district steam or district hot water) in 1999. There were only five building types with statistically significant district heat consumption; education buildings used the most total district heat. Figure showing total district heat consumption by building type. If you need assistance viewing this page, please call 202-586-8800. District Heat Consumption per Building by Building Type Health care buildings used the most district heat per building. Figure showing district heat consumption per building by building type. If you need assistance viewing this page, please call 202-586-8800.

125

Approximating European Options by Rebate Barrier Options  

E-Print Network [OSTI]

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

Song, Qingshuo

2011-01-01T23:59:59.000Z

126

Heat storage with CREDA  

SciTech Connect (OSTI)

The principle of operation of ETS or Electric Thermal Storage is discussed in this book. As can be seen by the diagram presented, heating elements buried deep within the core are energized during off-peak periods or periods of lower cost energy. These elements charge the core to a per-determined level, then during the on-peak periods when the cost of electricity is higher or demand is higher, the heat is extracted from the core. The author discusses how this technology has progressed to the ETS equipment of today; this being the finer control of charging rates and extraction of heat from the core.

Beal, T. (Fostoria Industries, Fostoria, OH (US))

1987-01-01T23:59:59.000Z

127

The Broadband Heating Rate Profile (BBHRP) VAP  

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

brown-97.pdf Clothiaux, E. E., T. P. Ackerman, G. G. Mace, K. P. Moran, R. T. Marchand, M. Miller, and B. E. Martner, 2000: Objective determination of cloud heights and...

128

IEA Heat Pump Workshop November 8, 2011  

E-Print Network [OSTI]

Responsible load growth a goal Residential rates low-- $0.01/kWh Sales of air source Heat Pumps a goal #12IEA Heat Pump Workshop November 8, 2011 Atlanta, Georgia #12;Heat Pump Reliability And Installer.3 Million customers 1.1 million residential customers #12;How did Alabama Power Company get into Heat Pump

Oak Ridge National Laboratory

129

Illustrative Calculation of Economics for Heat Pump and "Grid...  

Energy Savers [EERE]

Illustrative Calculation of Economics for Heat Pump and "Grid-Enabled" Water Heaters Illustrative Calculation of Economics for Heat Pump and "Grid-Enabled" Water Heaters Rate...

130

Heat transfer via dropwise condensation on hydrophobic microstructured surfaces .  

E-Print Network [OSTI]

??Dropwise condensation has the potential to greatly increase heat transfer rates. Heat transfer coefficients by dropwise condensation and film condensation on microstructured silicon chips were… (more)

Ruleman, Karlen E. (Karlen Elizabeth)

2009-01-01T23:59:59.000Z

131

STUDY OF FROST GROWTH ON HEAT EXCHANGERS USED AS OUTDOOR COILS IN AIR SOURCE HEAT PUMP SYSTEMS  

E-Print Network [OSTI]

STUDY OF FROST GROWTH ON HEAT EXCHANGERS USED AS OUTDOOR COILS IN AIR SOURCE HEAT PUMP SYSTEMS OF FROST GROWTH ON HEAT EXCHANGERS USED AS OUTDOOR COILS IN AIR SOURCE HEAT PUMP SYSTEMS Dissertation . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 3.5.3 Air Side Heat Transfer Rates . . . . . . . . . . . . . . . . . . 43 3.5.4 Fluid Side Heat

132

Analysis of cross-flow mixed convection with applications to building heat transfer  

SciTech Connect (OSTI)

A numerical simulation model has been developed for partial enclosure with restricted inlet and outlet simulating the building fluid flow and heat transfer scenario. Computed results are presented for a number of geometric configurations over a wide range of Reynolds and Rayleigh numbers and validated with available experimental data. The physical processes were modeled by solving equations for the conservation of mass, momentum, and energy with appropriate boundary conditions. The properties of the fluid were assumed to remain approximately constant over the range of operation and the buoyancy was incorporated using the Boussinesq approximation. The k-{var_epsilon} model was used for the simulation of turbulence. The computed results included the local velocity and temperature and the variation of local heat transfer coefficient along the heated side wall. Computed results showed excellent agreement with experimental data. The flow pattern within the enclosure was found to be quite complex in nature and consisted of a core flow due to forced convection near the central region of the enclosure and strong buoyancy induced flow near the heated side walls. It was found that as the flow rate through the enclosure increased, the enhancement of heat transfer above that for natural convection alone, also increased. The variation of the local heat transfer coefficient over the heated surface was found to be strongly affected by the recirculation of portions of the forced flow within the enclosure as well as the impingement to or separation of flow from the side walls in some regions.

Gao, S.; Rahman, M.M.

1999-07-01T23:59:59.000Z

133

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...

134

Algorithms for Polytope Covering and Approximation, and for Approximate  

E-Print Network [OSTI]

@research.att.com Abstract This paper gives an algorithm for polytope covering: let L and U be sets of points in RdAlgorithms for Polytope Covering and Approximation, and for Approximate Closest-point Queries draft , comprising n points altogether. A cover for L from U is a set C U with L a subset of the convex hull of C

Clarkson, Kenneth L.

135

Algorithms for Polytope Covering and Approximation, and for Approximate  

E-Print Network [OSTI]

@research.att.com Abstract This paper gives an algorithm for polytope covering : let L and U be sets of points in R dAlgorithms for Polytope Covering and Approximation, and for Approximate Closest-point Queries draft , comprising n points altogether. A cover for L from U is a set C #26; U with L a subset of the convex hull

Clarkson, Kenneth L.

136

Algorithms for Polytope Covering and Approximation, and for Approximate  

E-Print Network [OSTI]

an algorithm for polytope covering: let L and U be sets of points in Rd, comprising n points altogether Algorithms for Polytope Covering and Approximation, and for Approximate. A cover for L from U is a set C U with L a subset of the convex hull of C. Suppose c

Clarkson, Kenneth L.

137

Application Study of a Single House Horizontal Heating System  

E-Print Network [OSTI]

It is imperative to get new heating systems into the market and implement rate structures with heat meters for the purpose of energy conservation and environmental protection. Based on analysis of current heating technology, this paper analyzes...

Hang, Y.; Ying, D.

2006-01-01T23:59:59.000Z

138

Research and Development Roadmap for Emerging Water Heating Technologi...  

Energy Savers [EERE]

fuels are split approximately evenly between gas and electric, with other (e.g., fuel oil, propane) representing only 5% of residential water heating energy consumption. Figure...

139

Experimental study on heat transfer characteristics of internal heat exchangers for CO2 system under cooling condition  

Science Journals Connector (OSTI)

This paper presents the heat transfer characteristics of the internal heat exchanger (IHX) for CO2 heat pump system. The influence on the IHX length, the mass flow rate, the shape of IHX, the operating condition,...

Young Chul Kwon; Dae Hoon Kim; Jae Heon Lee…

2009-03-01T23:59:59.000Z

140

The Temperature of Interstellar Clouds from Turbulent Heating  

E-Print Network [OSTI]

To evaluate the effect of turbulent heating in the thermal balance of interstellar clouds, we develop an extension of the log-Poisson intermittency model to supersonic turbulence. The model depends on a parameter, d, interpreted as the dimension of the most dissipative structures. By comparing the model with the probability distribution of the turbulent dissipation rate in a simulation of supersonic and super-Alfvenic turbulence, we find a best-fit value of d=1.64. We apply this intermittency model to the computation of the mass-weighted probability distribution of the gas temperature of molecular clouds, high-mass star-forming cores, and cold diffuse HI clouds. Our main results are: i) The mean gas temperature in molecular clouds can be explained as the effect of turbulent heating alone, while cosmic ray heating may dominate only in regions where the turbulent heating is low; ii) The mean gas temperature in high-mass star-forming cores with typical FWHM of ~6 km/s (corresponding to a 1D rms velocity of 2.5 km/s) may be completely controlled by turbulent heating, which predicts a mean value of approximately 36 K, two to three times larger than the mean gas temperature in the absence of turbulent heating; iii) The intermittency of the turbulent heating can generate enough hot regions in cold diffuse HI clouds to explain the observed CH+ abundance, if the rms velocity on a scale of 1 pc is at least 3 km/s, in agreement with previous results based on incompressible turbulence. Because of its importance in the thermal balance of molecular clouds and high-mass star-forming cores, the process of turbulent heating may be central in setting the characteristic stellar mass and in regulating molecular chemical reactions.

Liubin Pan; Paolo Padoan

2008-06-30T23:59:59.000Z

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Heat Stroke  

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

stress, from exertion or hot environments, places stress, from exertion or hot environments, places workers at risk for illnesses such as heat stroke, heat exhaustion, or heat cramps. Heat Stroke A condition that occurs when the body becomes unable to control its temperature, and can cause death or permanent disability. Symptoms â–  High body temperature â–  Confusion â–  Loss of coordination â–  Hot, dry skin or profuse sweating â–  Throbbing headache â–  Seizures, coma First Aid â–  Request immediate medical assistance. â–  Move the worker to a cool, shaded area. â–  Remove excess clothing and apply cool water to their body. Heat Exhaustion The body's response to an excessive loss of water and salt, usually through sweating. Symptoms â–  Rapid heart beat â–  Heavy sweating â–  Extreme weakness or fatigue â– 

142

Thermosolutal convection from a discrete heat and solute source in a vertical porous annulus  

E-Print Network [OSTI]

on the fluid flow and heat and mass transfer rates. The porous annulus is subject to heat and mass fluxes from, buoyancy ratio and radius ratio are investigated on the flow patterns, and heat and mass transfer rates and the rates of heat and mass transfer strongly depend on the location of the heat and solute source. Further

Lopez, John M.

143

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...

144

Marketing the Klamath Falls Geothermal District Heating system  

SciTech Connect (OSTI)

The Klamath Falls Geothermal District Heating system was completed in 1981 and, until 1992, there was no formal marketing plan for the system. This lack of marketing and the system history of poor availability combined to reduce or eliminate interest in connecting on the part of local building owners and it served only the original 14 government buildings connected at start up. The revenue from these buildings, however, did not cover the entire cost of operating the system. As a result, the city was faced with a difficult decision - develop the revenue required to make the system self-supporting or shut it down. As a result, a marketing strategy for the system was developed. A flat rate was developed in which the rate is negotiable, but for most customers approximates 50% of the gas bill. In addition, the flat rate reduced customer retrofit costs because it is not necessary to buy a meter. Finally, the flat rate is a guaranteed value for the first 10 years of the contract. To reduce retrofit costs, the new marketing plan eliminates the requirement for a customer heat exchanger. New customers are now connected directly into the distribution system with district loop water used as the building heating medium. The state operates two programs which have been used in the marketing plan. The first of these is available only to taxable entities and is referred to as the Business Energy Tax Credit (BETC). This program offers business a 35% tax credit on the costs associated with connection to the geothermal district heat system (retrofit, design, permits, etc.). The second state program is the Small Energy Loan Program (SELP). This program will loan the entire cost of the energy project to the customer. The new marketing strategy for the Klamath Falls system has concentrated on offering the customer an attractive and easy to understand rate structure, reduced retrofit cost and complexity for this building along with an attractive package of financing and tax credits. 1 tab.

Rafferty, K. (Geo-Heat Center, Klamath Falls, OR (United States))

1993-08-01T23:59:59.000Z

145

Forward approximation and backward approximation in fuzzy rough sets  

Science Journals Connector (OSTI)

Abstract It is general to obtain rules by attribute reduction in fuzzy information systems. Instead of obtaining rules by attribute reduction, which may have a negative effect on inducting good rules, the objective of this paper is to extract rules without computing attribute reducts. Forward and backward approximations in fuzzy rough sets are first defined, and their important properties are discussed. Two algorithms based on forward and backward approximations, namely, mine rules based on the forward approximation (MRBFA) and mine rules based on the backward approximation (MRBBA), are proposed for rule extraction. The two algorithms are evaluated by several data sets from the UC Irvine Machine Learning Repository. The experimental results show that both MRBFA and MRBBA achieve better classification performances than the method based on attribute reduction.

Yi Cheng

2015-01-01T23:59:59.000Z

146

Application of release rate data to hazard load calculations  

Science Journals Connector (OSTI)

The author illustrates methods of applying heat, smoke and toxic gas release rate data to calculating fire hazard loading values.

Edwin E. Smith

1974-08-01T23:59:59.000Z

147

Heat Transfer of a Multiple Helical Coil Heat Exchanger Using a Microencapsulated Phase Change Material Slurry  

E-Print Network [OSTI]

The present study has focused on the use of coil heat exchangers (CHEs) with microencapsulated phase change material (MPCM) slurries to understand if CHEs can yield greater rates of heat transfer. An experimental study was conducted using a...

Gaskill, Travis

2012-02-14T23:59:59.000Z

148

Heat collector  

DOE Patents [OSTI]

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.

Merrigan, Michael A. (Santa Cruz, NM)

1984-01-01T23:59:59.000Z

149

Heat collector  

DOE Patents [OSTI]

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.

Merrigan, M.A.

1981-06-29T23:59:59.000Z

150

Consumer Winter Heating Oil Costs  

Gasoline and Diesel Fuel Update (EIA)

5 5 Notes: Using the Northeast as a regional focus for heating oil, the typical oil-heated household consumes about 680 gallons of oil during the winter, assuming that weather is "normal." The previous three winters were warmer than average and generated below normal consumption rates. Last winter, consumers saw large increases over the very low heating oil prices seen during the winter of 1998-1999 but, outside of the cold period in late January/early February they saw relatively low consumption rates due to generally warm weather. Even without particularly sharp cold weather events this winter, we think consumers are likely to see higher average heating oil prices than were seen last winter. If weather is normal, our projections imply New England heating oil

151

Approximation Algorithms for Covering Problems  

E-Print Network [OSTI]

?-approximation for general CIP with {0, 1} variables [24].details of an extension to CIP with general upper bounds onCovering Integer Programs ( CIP ). Given a non-negative cost

Koufogiannakis, Christos

2009-01-01T23:59:59.000Z

152

The Born-Oppenheimer Approximation  

Science Journals Connector (OSTI)

In physics and chemistry the Born-Oppenheimer approximation is a very important method for...1). It is based on the important fact that the molecular Schrödinger operator contains one small parameter, the ratio k

J. M. Combes; P. Duclos; R. Seiler

1981-01-01T23:59:59.000Z

153

Rates - WAPA-137 Rate Order  

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

WAPA-137 Rate Order WAPA-137 Rate Order 2009 CRSP Management Center Customer Rates Second Step Presentation from the June 25, 2009, Customer Meeting Handout Materials from the June 25, 2009, Customer Meeting Customer Comment Letters ATEA CREDA Farmington ITCA AMPUA Rate Adjustment Information The second step of WAPA-137 SLCA/IP Firm Power, CRSP Transmission and Ancillary Services rate adjustment. FERC Approval of Rate Order No. WAPA-137 Notice Of Filing for Rate Order No. WAPA-137 Published Final FRN for Rate Order No. WAPA-137 Letter to Customers regarding the published Notice of Extension of Public Process for Rate Order No. WAPA-137 Published Extension of Public Process for Rate Order No. WAPA-137 FRN Follow-up Public Information and Comment Forum Flier WAPA-137 Customer Meetings and Rate Adjustment Schedule

154

THEORY AND SIIVIULATION OF CYCIDTRON HEATING IN A LINEAR OCIUPOLE  

E-Print Network [OSTI]

conductivity model is used to calculate the cyclotron heating rate (electron or ion) in an arbitrary non been used to calculate the cyclotron heating rate for plasmas in various magnetic field configurations. This paper presents a method of calculating cyclotron heating rates that is based on integration of the local

Sprott, Julien Clinton

155

Rating of Mixed Split Residential Air Conditioners  

E-Print Network [OSTI]

by the indoor fan, the indoor fan is characterized by its power needed to provide this CFM, and the expansion device is characterized by its restrictiveness to the refrigerant flow (explained later). A computer model of a heat pump was used in this study.... The structure of HPSIM is modular. The model consists of 41 subprograms for heat pump component simulation, heat transfer, fluid mechan- ics, and fluid property calculation. The program totals approximately 5000 Fortran statements. UncL -'< Fig. 2...

Domanski, P. A.

1988-01-01T23:59:59.000Z

156

Water Heating | OpenEI  

Open Energy Info (EERE)

Water Heating Water Heating Dataset Summary Description Provides total and average household expenditures on energy for water heating in the United States in 2005. Source EIA Date Released September 01st, 2008 (6 years ago) Date Updated January 01st, 2009 (6 years ago) Keywords Energy Expenditures Residential Water Heating Data application/vnd.ms-excel icon 2005_Total.Expenditures.for_.Water_.Heating_EIA.Sep_.2008.xls (xls, 70.1 KiB) application/vnd.ms-excel icon 2005_Avg.Expenditures.for_.Water_.Heating_EIA.Sep_.2008.xls (xls, 69.1 KiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Time Period 2005 License License Other or unspecified, see optional comment below Comment Rate this dataset Usefulness of the metadata Average vote Your vote

157

Heat Transfer at Small Grashof Numbers  

Science Journals Connector (OSTI)

...January 1957 research-article Heat Transfer at Small Grashof Numbers J. J...physical arguments suggest that the heat transfer from a body, immersed in a fluid...the problem is small. However, heat-transfer rates predicted in this fashion...

1957-01-01T23:59:59.000Z

158

Fusion rates for hydrogen isotopic molecules of relevance for ‘‘cold fusion’’  

Science Journals Connector (OSTI)

In response to the recent announcements of evidence for room-temperature fusion in the electrolysis of D2O, we have analyzed how the fusion rate depends on the reduced mass of the fusing nuclei, the effective mass of a ‘‘heavy’’ electron, and the degree of vibrational excitation. Our results have been obtained both by accurately solving the Schrödinger equation for the hydrogen molecule and by using the WKB approximation. We find that in light of the reported d-d fusion rate, the excess heat in the experiment by Fleischmann, Pons, and Hawkins [J. Electroanal. Chem. 261, 301 (1989)] is difficult to explain in terms of conventional nuclear processes.

K. Szalewicz; J. D. Morgan; III; H. J. Monkhorst

1989-09-01T23:59:59.000Z

159

Effects of the Boussinesq Approximation on the Results of Strongly-Buoyant Plume Calculations  

Science Journals Connector (OSTI)

Nearly all mathematical models which are commonly used to predict the dispersion of chimney gases in the atmosphere or heated water discharges in the aquatic environment employ the so-called Boussinesq approximation. It is part of this ...

M. Schatzmann; A. J. Policastro

1984-01-01T23:59:59.000Z

160

Multidimensional mechanistic modeling of interfacial heat and mass transfer  

SciTech Connect (OSTI)

A combined theoretical and computational study in modeling multidimensional, diabatic vapor/liquid flows is presented. Models have been developed governing kinematic aspects of multiphase flow as well as interfacial mass and heat transfer for flows of condensable gas (vapor) and liquids. The modeling formulation is based on the Reynolds averaged Navier-Stokes (RANS) type multi-field approach which utilizes a complete set of conservation equations for each fluid component 1. The modeled interfacial interactions include energy, mass, and momentum transfer. Emphasis in the model development work has been placed on the mechanisms governing coupled interfacial heat and mass transfer between the liquid and vapor fields (condensation and/or boiling). A method for tracking changes in bubble size is presented and tested. Locally based models of multidimensional effects have been analyzed, including distributions of fluid temperatures and volume fractions. The overall model accounts for both kinematic and thermodynamic nonequilibrium between the component fluids including superheated vapor. The model has been implemented in the NPHASE-CMFD computer code. Results from the kinematic model are compared to experimental data and good agreement is demonstrated. The heat and mass transfer model is parametrically tested to show the multidimensional effects on the rate of heat and mass transfer. These effects are explained in terms of local characteristics of the two-phase flow. The model is applied to a scenario of saturated vapor injected into a subcooled flow through a heated, porous wall. This provides a reasonable approximation to subcooled boiling. The results are found to be dependent on the partitioning of the wall heat flux between direct liquid heating and vapor generation. However, the observed dependencies are explained and the modeling is considered consistent. (authors)

Shaver, D. R.; Antal, S. P.; Podowski, M. Z. [Center for Multiphase Research, Rensselaer Polytechnic Inst., Troy, NY (United States)

2012-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

AGN Heating through Cavities and Shocks  

E-Print Network [OSTI]

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

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

2006-11-04T23:59:59.000Z

162

Heating System Specification Specification of Heating System  

E-Print Network [OSTI]

Appendix A Heating System Specification /* Specification of Heating System (loosely based */ requestHeat : Room ­? bool; 306 #12; APPENDIX A. HEATING SYSTEM SPECIFICATION 307 /* user inputs */ livingPattern : Room ­? behaviour; setTemp : Room ­? num; heatSwitchOn, heatSwitchOff, userReset : simple

Day, Nancy

163

Ancilla Approximable Quantum State Transformations  

E-Print Network [OSTI]

We consider the transformations of quantum states obtainable by a process of the following sort. Combine the given input state with a specially prepared initial state of an auxiliary system. Apply a unitary transformation to the combined system. Measure the state of the auxiliary subsystem. If (and only if) it is in a specified final state, consider the process successful, and take the resulting state of the original (principal) system as the result of the process. We review known information about exact realization of transformations by such a process. Then we present results about approximate realization of finite partial transformations. We consider primarily the issue of approximation to within a specified positive epsilon, but we also address the question of arbitrarily close approximation.

Andreas Blass; Yuri Gurevich

2014-03-30T23:59:59.000Z

164

Quasiclassical Born-Oppenheimer approximations  

E-Print Network [OSTI]

We discuss several problems in quasiclassical physics for which approximate solutions were recently obtained by a new method, and which can also be solved by novel versions of the Born-Oppenheimer approximation. These cases include the so-called bouncing ball modes, low angular momentum states in perturbed circular billiards, resonant states in perturbed rectangular billiards, and whispering gallery modes. Some rare, special eigenstates, concentrated close to the edge or along a diagonal of a nearly rectangular billiard are found. This kind of state has apparently previously escaped notice.

Oleg Zaitsev; R. Narevich; R. E. Prange

2000-09-29T23:59:59.000Z

165

Determination of heat conductivity and thermal diffusivity of waste glass melter feed: Extension to high temperatures  

SciTech Connect (OSTI)

The heat conductivity ({lambda}) and the thermal diffusivity (a) of reacting glass batch, or melter feed, control the heat flux into and within the cold cap, a layer of reacting material floating on the pool of molten glass in an all-electric continuous waste glass melter. After previously estimating {lambda} of melter feed at temperatures up to 680 deg C, we focus in this work on the {lambda}(T) function at T > 680 deg C, at which the feed material becomes foamy. We used a customized experimental setup consisting of a large cylindrical crucible with an assembly of thermocouples, which monitored the evolution of the temperature field while the crucible with feed was heated at a constant rate from room temperature up to 1100°C. Approximating measured temperature profiles by polynomial functions, we used the heat transfer equation to estimate the {lambda}(T) approximation function, which we subsequently optimized using the finite-volume method combined with least-squares analysis. The heat conductivity increased as the temperature increased until the feed began to expand into foam, at which point the conductivity dropped. It began to increase again as the foam turned into a bubble-free glass melt. We discuss the implications of this behavior for the mathematical modeling of the cold cap.

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

2014-05-12T23:59:59.000Z

166

Rate schedule  

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

Firm Power Service Provided by Rate/Charges Firm Power Service Provided by Rate/Charges Rate/Charges Effective Through (or until superceded) Firm Sales (SLIP-F9) Composite Rate SLIP 29.62 mills/kWh 9/30/2015 Demand Charge SLIP $5.18/kW-month 9/30/2015 Energy Charge SLIP 12.19 mills/kWh 9/30/2015 Cost Recovery Charge (CRC) SLIP 0 mills/kWh 9/30/2015 Transmission Service Provided by Current Rates effective10/12 - 9/15 (or until superceded) Rate Schedule Effective Through Firm Point-to-Point Transmission (SP-PTP7) CRSP $1.14 per kW-month $13.69/kW-year $0.00156/kW-hour $0.04/kW-day $0.26/kW-week 10/1/2008-9/30/2015 Network Integration Transmission (SP-NW3) CRSP see rate schedule 10/1/2008-9/30/2015 Non-Firm Point-to-Point Transmission (SP-NFT6) CRSP see rate schedule 10/1/2008-9/30/2015 Ancillary Services Provided by Rate Rate Schedule

167

Effects of the boussinesq approximation on the results of strongly-buoyant plume calculations  

SciTech Connect (OSTI)

Nearly all mathematical models which are commonly used to predict the dispersion of chimney gases in the atmosphere or heated water discharges in the aquatic environment employ the so-called boussinesq approximation. It is part of this approximation that density variations appear solely in the buoyancy term of the momentum equation and are neglected in all other terms.

Schatzmann, M.; Policastro, A.J.

1984-01-01T23:59:59.000Z

168

Heat exchanger containing a component capable of discontinuous movement  

DOE Patents [OSTI]

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.

Wilson, David Gordon (Winchester, MA)

2002-01-01T23:59:59.000Z

169

Heat exchanger containing a component capable of discontinuous movement  

DOE Patents [OSTI]

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.

Wilson, D.G.

1993-11-09T23:59:59.000Z

170

Near-field heat transfer between a nanoparticle and a rough surface  

E-Print Network [OSTI]

In this work we focus on the surface roughness correction to the near-field radiative heat transfer between a nanoparticle and a material with a rough surface utilizing a direct perturbation theory up to second order in the surface profile. We discuss the different distance regimes for the local density of states above the rough material and the heat flux analytically and numerically. We show that the heat transfer rate is larger than that corresponding to a flat surface at short distances. At larger distances it can become smaller due to surface polariton scattering by the rough surface. For distances much smaller than the correlation length of the surface profile, we show that the results converge to a proximity approximation, whereas in the opposite limit the rough surface can be replaced by an equivalent surface layer.

Svend-Age Biehs; Jean-Jacques Greffet

2011-03-11T23:59:59.000Z

171

Minimal universal quantum heat machine  

E-Print Network [OSTI]

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

David Gelbwaser-Klimovsky; Robert Alicki; Gershon Kurizki

2012-09-06T23:59:59.000Z

172

SOOT GENERATION IN FIRES: AN IMPORTANT PARAMETER FOR ACCURATE CALCULATION OF HEAT RELEASE  

E-Print Network [OSTI]

states that heat of complete combustion per unit mass of oxygen consumed is approximately constant similarly states that heat of complete combustion per unit mass of carbon dioxide generated is approximately constant for most organic liquid, gaseous and solid compounds [1]. The heat of combustion per unit mass

Paris-Sud XI, Université de

173

Approximate Method for the Free Energy  

Science Journals Connector (OSTI)

......Articles Approximate Method for the Free Energy Akihide Oguchi Department of Physics...a lower bound of the Helmholtz free energy in the statistical physics. A new approximate expression of the free energy is obtained. This approximate......

Akihide Oguchi

1976-11-01T23:59:59.000Z

174

Approximate convex decomposition and its applications  

E-Print Network [OSTI]

in representations with an unmanageable number of components. In this work, we have developed an approximate technique, called Approximate Convex Decomposition (ACD), which decomposes a given polygon or polyhedron into "approximately convex" pieces that may provide...

Lien, Jyh-Ming

2009-05-15T23:59:59.000Z

175

Efficiency Ratings for the Daiken AC (Americas), Inc.  

E-Print Network [OSTI]

Efficiency Ratings for the Daiken AC (Americas), Inc. Altherma Air-to-Water Source Heat Pump System Description Model No. Capacity (tons) Space Heating Space Cooling SEER Water Heating Efficiency (E.F.)1 CEC Listing Date Heating Combined Hydronic HSPF E.F. Split Altherma LT ERLQ036

176

Geothermal district heating systems  

SciTech Connect (OSTI)

Ten district heating demonstration projects and their present status are described. The projects are Klamath County YMCA, Susanville District Heating, Klamath Falls District Heating, Reno Salem Plaza Condominium, El Centro Community Center Heating/Cooling, Haakon School and Business District Heating, St. Mary's Hospital, Diamond Ring Ranch, Pagosa Springs District Heating, and Boise District Heating.

Budney, G.S.; Childs, F.

1982-01-01T23:59:59.000Z

177

Proceedings of HT'03 2003 Summer Heat Transfer Conference  

E-Print Network [OSTI]

Proceedings of HT'03 2003 Summer Heat Transfer Conference July 21­23, 2003, Las Vegas, Nevada, USA HT2003-47016 A NEW TECHNIQUE FOR HEAT FLUX DETERMINATION D.G. Walker Department of Mechanical@vt.edu ABSTRACT A new method for estimating heat fluxes from heating rate measurements and an approach to measure

Walker, D. Greg

178

Rock Hill Utilities - Water Heater and Heat Pump Rebate Program |  

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

Rock Hill Utilities - Water Heater and Heat Pump Rebate Program Rock Hill Utilities - Water Heater and Heat Pump Rebate Program Rock Hill Utilities - Water Heater and Heat Pump Rebate Program < Back Eligibility Residential Savings Category Heating & Cooling Commercial Heating & Cooling Heat Pumps Appliances & Electronics Water Heating Program Info State South Carolina Program Type Utility Rebate Program Rebate Amount Water Heater: up to $275 Heat Pump Replacement: $400 Provider Rock Hill Utilities Through the SmartChoice program, Rock Hill Utilities offers rebates for water heater and heat pump replacements. Information on financing for heat pumps can also be found on the web site listed above. If both the water heater and heat pump are purchased then the customer may qualify for the Great Rate program. The Great Rate program will add a 25% discount to a

179

Water and Space Heating Heat Pumps  

E-Print Network [OSTI]

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

Kessler, A. F.

1985-01-01T23:59:59.000Z

180

Radiation Pressure Supported AGN Tori with Hard X-Ray and Stellar Heating  

E-Print Network [OSTI]

The dynamics and structure of toroidal obscuration around AGN remain uncertain and controversial. In this paper we extend earlier work on the dynamical role of infrared radiation pressure by adding the effects of two kinds of distributed heating: Compton-heating due to hard X-rays from the nucleus and local starlight heating. We find numerical solutions to the axisymmetric hydrostatic equilibrium, energy balance, and photon diffusion equations including these effects. Within the regime of typical parameters, the two different sources of additional heating have very similar effects: the density profile within the torus becomes shallower both radially and vertically, but for plausible heating rates, there is only minor change (relative to the source-free case) in the distribution of column density with solid angle. The most interesting consequence of distributed heating is that it selects out a relatively narrow range of parameters permitting an equilibrium, particularly $(L/L_E)/\\tau_T$. We discuss the implications of both the narrowness of the permitted range and its approximate coincidence with the range inferred from observations.

Jiming Shi; Julian H. Krolik

2008-02-13T23:59:59.000Z

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Shock-Wave Heating Model for Chondrule Formation: Prevention of Isotopic Fractionation  

E-Print Network [OSTI]

Chondrules are considered to have much information on dust particles and processes in the solar nebula. It is naturally expected that protoplanetary disks observed in present star forming regions have similar dust particles and processes, so study of chondrule formation may provide us great information on the formation of the planetary systems. Evaporation during chondrule melting may have resulted in depletion of volatile elements in chondrules. However, no evidence for a large degree of heavy-isotope enrichment has been reported in chondrules. In order to meet this observed constraint, the rapid heating rate at temperatures below the silicate solidus is required to suppress the isotopic fractionation. We have developed a new shock-wave heating model taking into account the radiative transfer of the dust thermal continuum emission and the line emission of gas molecules and calculated the thermal history of chondrules. We have found that optically-thin shock waves for the thermal continuum emission from dust particles can meet the rapid heating constraint, because the dust thermal emission does not keep the dust particles high temperature for a long time in the pre-shock region and dust particles are abruptly heated by the gas drag heating in the post-shock region. We have also derived the upper limit of optical depth of the pre-shock region using the radiative diffusion approximation, above which the rapid heating constraint is not satisfied. It is about 1 - 10.

Hitoshi Miura; Taishi Nakamoto

2006-07-03T23:59:59.000Z

182

Approximating Metal-Insulator Transitions  

E-Print Network [OSTI]

We consider quantum wave propagation in one-dimensional quasiperiodic lattices. We propose an iterative construction of quasiperiodic potentials from sequences of potentials with increasing spatial period. At each finite iteration step the eigenstates reflect the properties of the limiting quasiperiodic potential properties up to a controlled maximum system size. We then observe approximate metal-insulator transitions (MIT) at the finite iteration steps. We also report evidence on mobility edges which are at variance to the celebrated Aubry-Andre model. The dynamics near the MIT shows a critical slowing down of the ballistic group velocity in the metallic phase similar to the divergence of the localization length in the insulating phase.

C. Danieli; K. Rayanov; B. Pavlov; G. Martin; S. Flach

2014-05-06T23:59:59.000Z

183

Heat transfer and heat exchangers reference handbook  

SciTech Connect (OSTI)

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.

Not Available

1991-01-15T23:59:59.000Z

184

Heating systems for heating subsurface formations  

DOE Patents [OSTI]

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.

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

2011-04-26T23:59:59.000Z

185

Heat Integration and Heat Recovery at a Large Chemical Manufacturing Plant  

E-Print Network [OSTI]

in the hydrogenation process. The hydrogenation process uses a catalyst to react the purified phenol with hydrogen, forming a mixture of cyclohexanone and cyclohexanol. The reaction is exothermic and is cooled with water to control the rate of reaction... Process Heat Recovery The process heat recovery opportunity was identified in the hydrogenation process. The hydrogenation process contains an exothermic reaction which is cooled with water to control the rate of reaction. The heated water...

Togna, K .A.

2012-01-01T23:59:59.000Z

186

Climate, extreme heat, and electricity demand in California  

SciTech Connect (OSTI)

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 as the July 2006 heat wave in California, suggests that peak electricity demand will challenge current supply, as well as future planned supply capacities when population and income growth are taken into account.

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

2008-04-01T23:59:59.000Z

187

Heat exchanger  

DOE Patents [OSTI]

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.

Brackenbury, Phillip J. (Richland, WA)

1986-01-01T23:59:59.000Z

188

Heat exchanger  

DOE Patents [OSTI]

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.

Brackenbury, P.J.

1983-12-08T23:59:59.000Z

189

MARKOV CHAIN APPROXIMATIONS FOR TRANSITION DENSITIES OF LEVY PROCESSES  

E-Print Network [OSTI]

MARKOV CHAIN APPROXIMATIONS FOR TRANSITION DENSITIES OF L´EVY PROCESSES ALEKSANDAR MIJATOVI for the existence of transition densities of X, we establish sharp convergence rates of the normalised probability class with applications in diverse areas such as mathematical finance, risk management, insurance

190

Rough Set Approximations in Formal Concept Analysis  

E-Print Network [OSTI]

Rough Set Approximations in Formal Concept Analysis Y.Y. Yao, Yaohua Chen Department of Computer}@cs.uregina.ca Abstract-- An important topic of rough set theory is the approximation of undefinable sets or concepts of approximation operators. In this paper, the notion of rough set approximations is introduced into formal concept

Yao, Yiyu

191

Jones-Onslow EMC - Residential Heating and Cooling Rebate Program |  

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

Jones-Onslow EMC - Residential Heating and Cooling Rebate Program Jones-Onslow EMC - Residential Heating and Cooling Rebate Program Jones-Onslow EMC - Residential Heating and Cooling Rebate Program < Back Eligibility Residential Savings Category Heating & Cooling Commercial Heating & Cooling Cooling Heat Pumps Program Info State North Carolina Program Type Utility Rebate Program Rebate Amount Central AC (15 SEER or greater): $35 Central AC (16 SEER or greater): $50 Heat Pump (15 SEER or greater): $250 Geothermal Heat Pump (19 EER or greater): $350 Provider Jones-Onslow EMC Jones-Onslow Electric Membership Corporation offers rebates to residential members who install energy efficient heating and cooling equipment. Members can replace an existing central AC or heat pump, which does not have a SEER rating greater than 13, with a central AC, heat pump, or geothermal heat

192

A combined heat-transfer analysis of a single-fiber CVD reactor  

SciTech Connect (OSTI)

In high-temperature applications, structural fibers such as SiC are currently being considered for reinforcement of both ceramic and intermetallic matrices. A combined-conjugated heat-transfer and fluid-flow analysis is presented for coating fibers by CVD in a vertical cylindrical quartz reactor. The numerical model focuses on radiation and natural convection. Three case studies are performed, and the wall temperature predictions are compared to experimental measurements. In the first case, the flowing gas is hydrogen, and conduction is more important than both radiation and convection, in which case measured and predicted wall temperatures agree excellently. In the second, hydrogen is replaced by argon, thus making radiation heat transfer more important than the previous situation. Three radiation models with increasing degrees of sophistication are compared: an approximate nongray model (no wavelength dependence of emissivity), an approximate semigray model, and a rigorous semigray model with view factor calculations. Comparison with experiments suggest that a semigray radiative analysis is needed for correct determination of wall temperatures. The third involves argon at a lower flow rate, where natural convection effects are more pronounced. Checking the validity of the Boussinesq approximation by incorporating the explicit dependence of density on temperature in the model shows a slight difference between the velocity fields predicted using the Boussinesq approximation and those obtained using the explicit dependence of density on temperature. However, there is negligible difference between the temperature fields predicted in the two cases.

Kassemi, M.; Gokoglu, S.A.; Panzarella, C.H.; Veitch, L.C. (NASA Lewis Research Center, Cleveland, OH (United States))

1993-10-01T23:59:59.000Z

193

Segmented heat exchanger  

DOE Patents [OSTI]

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.

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

2010-12-14T23:59:59.000Z

194

Heat Trace and Functional Determinant in One Dimension  

E-Print Network [OSTI]

We study the spectral properties of the Laplace type operator on the circle. We discuss various approximations for the heat trace, the zeta function and the zeta-regularized determinant. We obtain a differential equation for the heat kernel diagonal and a recursive system for the diagonal heat kernel coefficients, which enables us to find closed approximate formulas for the heat trace and the functional determinant which become exact in the limit of infinite radius. The relation to the generalized KdV hierarchy is discussed as well.

Ivan G Avramidi

2014-06-05T23:59:59.000Z

195

Developing Anthropogenic Heating Profiles for Urban Areas Across the United States  

E-Print Network [OSTI]

and approximate state-wide fuel efficiency. Heat added by buildings take into account electricity (e.g., AC systems, appliances) and heating fuel usage. The building component relies on both population and climate, as heating and cooling degree days are proportional to the amount of heating fuel and electricity used

Hall, Sharon J.

196

Thermohydraulic Simulation of Heat Exchanger Networks  

Science Journals Connector (OSTI)

The determination of network temperatures is carried out together with the evaluation of flow rates and pressures along the network, considering head losses in heat exchangers and associated piping. ... The HEN responsible to distribute cooling water in an industrial unit is composed by three heat exchangers in parallel. ... However, the cooling water distribution among the three exchangers presents a considerable unbalance, where heat exchanger E-101 receives much less cooling water than the design specification. ...

Viviane B. G. Tavares; Eduardo M. Queiroz; Andre? L. H. Costa

2010-04-26T23:59:59.000Z

197

Heat transfer in the spin-boson model: A comparative study in the incoherent tunneling regime  

Science Journals Connector (OSTI)

We study the transfer of heat in the nonequilibrium spin-boson model with an Ohmic dissipation. In the nonadiabatic limit we derive a formula for the thermal conductance based on a rate equation formalism at the level of the noninteracting blip approximation, valid for temperatures T>TK, with TK as the Kondo temperature. We evaluate this expression analytically assuming either weak or strong couplings, and demonstrate that our results agree with exact relations. Far-from-equilibrium situations are further examined, showing a close correspondence to the linear response limit.

Dvira Segal

2014-07-31T23:59:59.000Z

198

Fabric composite heat pipe technology development  

SciTech Connect (OSTI)

Testing has been performed on a variety of fabric composite technology feasibility issues. These include an evaluation of the effective radiation heat transfer rate from a heated metallic surface covered by a ceramic fabric with the intent of determining the effective emissivity'' of the combination of materials, studies of the wicking properties of ceramic fabrics, and the construction of fabric composite heat pipes to test their working properties under both steady state and transient conditions. Results of these experiments shown that fabric composite combinations have greatly enhanced effective emissivities'' resulting from the increases surface area of the fabric, ceramic fabrics can work very well as the wick for heat pipes, ceramic fabric heat pipes have been demonstrated to operate under typical space conditions, and large mass reductions are possible by using fabric composite heat pipes for heat rejection radiator systems.

Klein, A.C.; Gulshan-Ara, Z.; Kiestler, W.; Snuggerud, R.; Marks, T.S. (Department of Nuclear Engineering, Oregon State University, Corvallis, Oregon 97331 (United States))

1993-01-10T23:59:59.000Z

199

Multifamily Individual Heating and Ventilation Systems, Lawrence...  

Energy Savers [EERE]

each apartment were much higher than the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) 62.2 rate; an extensive system of ductwork, smoke and...

200

Condensing Heat Exchanger for Optimization of Energy Efficiency  

E-Print Network [OSTI]

out, rapid deterioration, due to acid corrosion, of the outlet duct and stack would result. With the development of the condensing heat exchanger, boiler efficiency can now exceed 90%. Approximately 1% gain in boiler efficiency can be expected...

Carrigan, J. F.; Johnson, D. W.; DiVitto, J. G.; Schulze, K. H.

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Influence of Infrared Radiation on Attic Heat Transfer  

E-Print Network [OSTI]

roof temperatures. It was found that a radiant barrier such as aluminum foil can reduce the heat flux significantly. Experimental results were compared to a Three-Region approximate solution developed at Oak Ridge National Laboratories (ORNL). The model...

Katipamula, S.; Turner, W. D.; Murphy, W. E.; O'Neal, D. L.

1985-01-01T23:59:59.000Z

202

ORIGINAL ARTICLE Approximate Truth and Descriptive Nesting  

E-Print Network [OSTI]

ORIGINAL ARTICLE Approximate Truth and Descriptive Nesting Jeffrey Alan Barrett Received: 7 July. This paper presents a notion of local probable approximate truth in terms of descriptive nesting relations

Barrett, Jeffrey A.

203

Exergoeconomic evaluation on the optimum heating circuit system of Simav geothermal district heating system  

Science Journals Connector (OSTI)

Simav is one of the most important 15 geothermal areas in Turkey. It has several geothermal resources with the mass flow rate ranging from 35 to 72 kg/s and temperature from 88 to 148 °C. Hence, these geothermal resources are available to use for several purposes, such as electricity generation, district heating, greenhouse heating, and balneological purposes. In Simav, the 5000 residences are heated by a district heating system in which these geothermal resources are used. Beside this, a greenhouse area of 225,000 m2 is also heated by geothermal. In this study, the working conditions of the Simav geothermal district heating system have been optimized. In this paper, the main characteristics of the system have been presented and the impact of the parameters of heating circuit on the system are investigated by the means of energy, exergy, and life cycle cost (LCC) concepts. As a result, the optimum heating circuit has been determined as 60/49 °C.

Oguz Arslan; M.Arif Ozgur; Ramazan Kose; Abtullah Tugcu

2009-01-01T23:59:59.000Z

204

Multi topological approximations of rough set theory  

Science Journals Connector (OSTI)

In this paper, we generalise Pawlak's approximation spaces to topological approximation spaces. These topological approximation spaces are generated using many topological notions such as regular open sets, semi-open sets, pre-open sets, ?-open sets, ?-open sets and ?-open sets and others. The basic definitions and properties of these topological approximation spaces are introduced and sufficiently illustrated. We put all topological generalisations in one generalisation called m-generalisation spaces.

A.S. Salama; O.G. El-Barbary

2013-01-01T23:59:59.000Z

205

Hydrotreater feed/effluent heat exchange  

SciTech Connect (OSTI)

This patent describes a hydrotreating process for catalytically hydrogenating a hydrocarbon stock. It comprises dividing the hydrocarbon stock into two portions comprising a major portion and a minor portion, mixing the major portion with hydrogen to form a major portion mixture at a first temperature, and passing the major portion mixture through a multiple pass tube furnace to yield a heated major portion mixture at a first reactor inlet temperature, passing the heated major portion mixture to a hydrogenation catalyst containing reactor, thereby hydrogenating and heating the major portion mixture by heat of reaction to a reactor outlet temperature, withdrawing a hot hydrogenated stock from the reactor at the reactor outlet temperature wherein the hot hydrogenated stock comprises the entire reactor effluent, mixing the minor portion with hydrogen to form a minor portion mixture at about the first temperature, heating the minor portion mixture by indirect heat exchange with the hot hydrogenated stock to a second reactor inlet temperature approximately equal to the first reactor inlet temperature and then passing the minor portion to the first hydrogenation catalyst containing reactor in the absence of additional heating, the minor portion in an amount sufficient to quench the hot hydrogenated stock to a third temperature approximately equal to the first reactor inlet temperature.

Steinberg, R.M.; Deshpande, V.A.

1991-08-13T23:59:59.000Z

206

Floatable solar heat modules  

SciTech Connect (OSTI)

A floating solar heat module for swimming pools comprises a solid surface for conducting heat from the sun's rays to the water and further includes a solid heat storage member for continual heating even during the night. A float is included to maintain the solar heat module on the surface of the pool. The solid heat storage medium is a rolled metal disk which is sandwiched between top and bottom heat conducting plates, the top plate receiving the heat of the sun's rays through a transparent top panel and the bottom plate transferring the heat conducted through the top plate and rolled disk to the water.

Ricks, J.W.

1981-09-29T23:59:59.000Z

207

Paving materials for heat island mitigation  

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

Paving materials for heat island mitigation Paving materials for heat island mitigation Title Paving materials for heat island mitigation Publication Type Report Year of Publication 1997 Authors Pomerantz, Melvin, Hashem Akbari, Allan Chen, Haider Taha, and Arthur H. Rosenfeld Keywords Cool Pavements, Heat Island Abstract This report summarizes paving materials suitable for urban streets, driveways, parking lots and walkways. The authors evaluate materials for their abilities to reflect sunlight, which will reduce their temperatures. This in turn reduces the excess air temperature of cities (the heat island effect). The report presents the compositions of the materials, their suitability for particular applications, and their approximate costs (in 1996). Both new and resurfacing are described. They conclude that, although light-colored materials may be more expensive than conventional black materials, a thin layer of light-colored pavement may produce energy savings and smog reductions whose long-term worth is greater than the extra cost.

208

Decay-phase Cooling and Inferred Heating of M- and X-class Solar Flares  

Science Journals Connector (OSTI)

In this paper, the cooling of 72 M- and X-class flares is examined using GOES/XRS and SDO/EVE. The observed cooling rates are quantified and the observed total cooling times are compared with the predictions of an analytical zero-dimensional hydrodynamic model. We find that the model does not fit the observations well, but does provide a well-defined lower limit on a flare's total cooling time. The discrepancy between observations and the model is then assumed to be primarily due to heating during the decay phase. The decay-phase heating necessary to account for the discrepancy is quantified and found be ~50% of the total thermally radiated energy, as calculated with GOES. This decay-phase heating is found to scale with the observed peak thermal energy. It is predicted that approximating the total thermal energy from the peak is minimally affected by the decay-phase heating in small flares. However, in the most energetic flares the decay-phase heating inferred from the model can be several times greater than the peak thermal energy.

Daniel F. Ryan; Phillip C. Chamberlin; Ryan O. Milligan; Peter T. Gallagher

2013-01-01T23:59:59.000Z

209

Approximation Algorithms for Maximization Problems arising in  

E-Print Network [OSTI]

Approximation Algorithms for Maximization Problems arising in Graph Partitioning Thesis for the M of size k that maximizes : Max­k­Vertex Cover : the weight of edges incident with vertices in U . Max a number of approximation algorithms based on linear and semidefinite programming, and obtain approximation

Langberg, Michael

210

Direct Observation of Born-Oppenheimer Approximation  

E-Print Network [OSTI]

Direct Observation of Born-Oppenheimer Approximation Breakdown in Carbon Nanotubes Adam W of the theoretically predicted breakdown of the Born-Oppenheimer approximation in individual single-walled carbon nanotubes. The Born-Oppenheimer (BO) or adiabatic approximation is widely used to simplify the very complex

Cronin, Steve

211

Mathematical Analysis of Born{Oppenheimer Approximations  

E-Print Network [OSTI]

Mathematical Analysis of Born{Oppenheimer Approximations George A. Hagedorn and Alain Joye concerning Born{Oppenheimer approximations in molecular quantum mechanics. Introduction The goal of this paper is to review rigorous mathematical results concerning Born{Oppenheimer approximations. We make

Hagedorn, George A.

212

Truth approximation via abductive belief change  

Science Journals Connector (OSTI)

......in Model-Based Reasoning and Abduction Truth approximation via abductive belief change...of belief change, on the one hand, and truth approximation, construed as increasing...or beliefs does lead them closer to the truth, and hence tracks truth approximation......

Gustavo Cevolani

2013-12-01T23:59:59.000Z

213

Estimates of heat flow from Cenozoic seafloor using global depth and age data  

E-Print Network [OSTI]

-independent estimate of the total heat output of Cenozoic seafloor is 18.6 to 20.5 TW, which leads to a global output: Oceanic heat flow; Global heat budget; Subsidence rate 1. Introduction The total heat output of the EarthEstimates of heat flow from Cenozoic seafloor using global depth and age data Meng Wei , David

Sandwell, David T.

214

Heat Pump for High School Heat Recovery  

E-Print Network [OSTI]

ICEBO2006, Shenzhen, China Renewable Energy Resources and a Greener Future Vol.VIII-12-1 Heat Pump for High School Bathroom Heat Recovery Kunrong Huang Hanqing Wang Xiangjiang Zhou Associate professor Professor Professor School...

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

2006-01-01T23:59:59.000Z

215

Industrial heat pumps - types and costs  

SciTech Connect (OSTI)

Confusion about energy savings and economics is preventing many potentially beneficial applications for industrial heat pumps. The variety of heat pumps available and the lack of a standard rating system cause some of this confusion. The authors illustrate how a simple categorization based on coefficient of performance (COP) can compare the cost of recovering waste energy with heat pumps. After evaluating examples in which the cost of energy delivered was calculated based on estimates of capital cost, operating costs, and maintenance costs, they compare heat pumps from the various categories on the basis of economics. 6 references, 6 figures, 1 table.

Chappell, R.N.; Bliem, C.J. Jr.; Mills, J.I.; Demuth, O.J.; Plaster, D.S.

1985-08-01T23:59:59.000Z

216

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...

217

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

Open Energy Info (EERE)

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

218

San Bernardino District Heating District Heating Low Temperature...  

Open Energy Info (EERE)

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

219

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...

220

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...

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Midland District Heating District Heating Low Temperature Geothermal...  

Open Energy Info (EERE)

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

222

Combined Heat and Power, Waste Heat, and District Energy | Department...  

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

Combined Heat and Power, Waste Heat, and District Energy Combined Heat and Power, Waste Heat, and District Energy Presentation-given at the Fall 2011 Federal Utility Partnership...

223

Waste Heat Management Options for Improving Industrial Process Heating Systems  

Broader source: Energy.gov [DOE]

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.

224

Guide to Geothermal Heat Pumps  

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

Geothermal Heat Pumps Work Using a heat exchanger, a geothermal heat pump can move heat from one space to another. In summer, the geothermal heat pump extracts heat from a building...

225

Waste Heat Recovery – Submerged Arc Furnaces (SAF)  

E-Print Network [OSTI]

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

O'Brien, T.

2008-01-01T23:59:59.000Z

226

AMBIPOLAR DIFFUSION HEATING IN TURBULENT SYSTEMS  

SciTech Connect (OSTI)

The temperature of the gas in molecular clouds is a key determinant of the characteristic mass of star formation. Ambipolar diffusion (AD) is considered one of the most important heating mechanisms in weakly ionized molecular clouds. In this work, we study the AD heating rate using two-fluid turbulence simulations and compare it with the overall heating rate due to turbulent dissipation. We find that for observed molecular clouds, which typically have Alfven Mach numbers of {approx}1 and AD Reynolds numbers of {approx}20, about 70% of the total turbulent dissipation is in the form of AD heating. AD has an important effect on the length scale where energy is dissipated: when AD heating is strong, most of the energy in the cascade is removed by ion-neutral drift, with a comparatively small amount of energy making it down to small scales. We derive a relation for the AD heating rate that describes the results of our simulations to within a factor of two. Turbulent dissipation, including AD heating, is generally less important than cosmic-ray heating in molecular clouds, although there is substantial scatter in both.

Li, Pak Shing [Astronomy Department, University of California, Berkeley, CA 94720 (United States); Myers, Andrew [Physics Department, University of California, Berkeley, CA 94720 (United States); McKee, Christopher F., E-mail: psli@astron.berkeley.edu, E-mail: atmyers@berkeley.edu, E-mail: cmckee@berkeley.edu [Physics Department and Astronomy Department, University of California, Berkeley, CA 94720 (United States)

2012-11-20T23:59:59.000Z

227

The Effect of Magnetic Turbulence Energy Spectra and Pickup Ions on the Heating of the  

E-Print Network [OSTI]

The Effect of Magnetic Turbulence Energy Spectra and Pickup Ions on the Heating of the Solar Wind C02101 (2010)], we have incorporated in the heating model the energy cascade rate based on Iroshnikov scale. Since in steady state, the heating rate is essentially the same as the energy cascade rate

Ng, Chung-Sang

228

Woven heat exchanger  

DOE Patents [OSTI]

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.

Piscitella, R.R.

1984-07-16T23:59:59.000Z

229

HEAT STORAGE AND ADVECTION IN THE NORTH PACIFIC OCEAN  

E-Print Network [OSTI]

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

Luther, Douglas S.

230

Towards Intelligent District Heating.  

E-Print Network [OSTI]

??A district heating system consists of one or more production units supplying energy in the form of heated water through a distribution pipe network to… (more)

Johansson, Christian

2010-01-01T23:59:59.000Z

231

Total Space Heat-  

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

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...

232

ARM - Heat Index Calculations  

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

FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans Heat Index Calculations Heat Index is an index that combines air temperature and relative...

233

HEATING AND COOLING PROTOSTELLAR DISKS  

SciTech Connect (OSTI)

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

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

2011-05-10T23:59:59.000Z

234

Predicting free laminar convection heat transfer on curvilinear surfaces  

SciTech Connect (OSTI)

Free laminar convection on an isothermal surface of cylindrical and axisymmetric bodies of arbitrary cross section is considered in the Boussinesq approximation. The problem is solved by the method of generalized similarity in its local approximation. Universal formulae are obtained for calculating the local Nusselt number. Prediction of convection on a heated horizontal cylindrical and sphere are given as examples of the method.

Stepanyants, L.G.; Shelukho, S.I.

1989-07-01T23:59:59.000Z

235

Electron Cyclotron Heating in a Non-Uniform Magnetic Field  

E-Print Network [OSTI]

Electron Cyclotron Heating in a Non-Uniform Magnetic Field by J.e. Sprott December 1968 Presented pulse. IN1RODUCTION Most previous theories of electron cyclotron resonance heating have dealt primarily will outline a simple theoretical model which can be used to estimate the electron cyclotron heating rate

Sprott, Julien Clinton

236

ARM - Measurement - Sensible heat flux  

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

govMeasurementsSensible heat flux govMeasurementsSensible heat flux 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 : Sensible heat flux The time rate of flow for the energy transferred from a warm or hot surface to whatever is touching it, typically air. Categories Surface Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments CO2FLX : Carbon Dioxide Flux Measurement Systems ECOR : Eddy Correlation Flux Measurement System EBBR : Energy Balance Bowen Ratio Station

237

ARM - Measurement - Latent heat flux  

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

govMeasurementsLatent heat flux govMeasurementsLatent heat flux 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 : Latent heat flux The time rate of flow for the specific enthalpy difference between two phases of a substance at the same temperature, typically water. Categories Surface Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments CO2FLX : Carbon Dioxide Flux Measurement Systems ECOR : Eddy Correlation Flux Measurement System EBBR : Energy Balance Bowen Ratio Station

238

Experimental techniques for measuring temperature and velocity fields to improve the use and validation of building heat transfer models  

SciTech Connect (OSTI)

When modeling thermal performance of building components and envelopes, researchers have traditionally relied on average surface heat-transfer coefficients that often do not accurately represent surface heat-transfer phenomena at any specific point on the component being evaluated. The authors have developed new experimental techniques that measure localized surface heat-flow phenomena resulting from convection. The data gathered using these new experimental procedures can be used to calculate local film coefficients and validate complex models of room and building envelope heat flows. These new techniques use a computer-controlled traversing system to measure both temperatures and air velocities in the boundary layer near the surface of a building component, in conjunction with current methods that rely on infrared (IR) thermography to measure surface temperatures. Measured data gathered using these new experimental procedures are presented here for two specimens: (1) a Calibrated Transfer Standard (CTS) that approximates a constant-heat-flux, flat plate; and (2) a dual-glazed, low-emittance (low-e), wood-frame window. The specimens were tested under steady-state heat flow conditions in laboratory thermal chambers. Air temperature and mean velocity data are presented with high spatial resolution (0.25- to 25-mm density). Local surface heat-transfer film coefficients are derived from the experimental data by means of a method that calculates heat flux using a linear equation for air temperature in the inner region of the boundary layer. Local values for convection surface heat-transfer rate vary from 1 to 4.5 W/m{sup 2} {center_dot} K. Data for air velocity show that convection in the warm-side thermal chamber is mixed forced/natural, but local velocity maximums occur from 4 to 8 mm from the window glazing.

Griffith, Brent; Turler, Daniel; Goudey, Howdy; Arasteh, Dariush

1998-04-01T23:59:59.000Z

239

Cab Heating and Cooling  

SciTech Connect (OSTI)

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.

Damman, Dennis

2005-10-31T23:59:59.000Z

240

Water Heating Products and Services | Department of Energy  

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

Water Heating Products and Services Water Heating Products and Services Water Heating Products and Services May 29, 2012 - 7:04pm Addthis Choosing an efficient water heater will help you save money and Energy. | Photo Credit Energy Department Choosing an efficient water heater will help you save money and Energy. | Photo Credit Energy Department Use the following links to get product information and locate professional services for water heating. Product Information Solar Pool Heating Systems Florida Solar Energy Center Listing of solar pool heating systems evaluated by the Florida Solar Energy Center. Certified Solar Collectors and Systems Solar Rating and Certification Corporation Information on solar collectors and pool heating systems certified under the various Solar Rating and Certification Corporation's rating programs.

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Water Heating Products and Services | Department of Energy  

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

Water Heating Products and Services Water Heating Products and Services Water Heating Products and Services May 29, 2012 - 7:04pm Addthis Choosing an efficient water heater will help you save money and Energy. | Photo Credit Energy Department Choosing an efficient water heater will help you save money and Energy. | Photo Credit Energy Department Use the following links to get product information and locate professional services for water heating. Product Information Solar Pool Heating Systems Florida Solar Energy Center Listing of solar pool heating systems evaluated by the Florida Solar Energy Center. Certified Solar Collectors and Systems Solar Rating and Certification Corporation Information on solar collectors and pool heating systems certified under the various Solar Rating and Certification Corporation's rating programs.

242

Effects of heat stress on mammalian reproduction  

Science Journals Connector (OSTI)

...University of Florida, , PO Box 110910...combustion of fuel stuffs to achieve a high metabolic rate (i.e. heat...to changes in energy balance and nutrient...on conception rate of dairy cattle...Hereford cattle in Florida. J. Anim. Sci...University of Florida, PO Box 110910...

2009-01-01T23:59:59.000Z

243

Rates & Repayment  

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

Environmental Review-NEPA Financial Data Operations Planning & Projects Power Marketing Rates Rate Adjustments Transmission Ancillary Services Rates WAPA-137 Rate Order Environmental Review-NEPA Financial Data Operations Planning & Projects Power Marketing Rates Rate Adjustments Transmission Ancillary Services Rates WAPA-137 Rate Order Rates and Repayment Services Rates Current and Historical Rate Information Collbran Power Rates CRSP Power Rates CRSP Transmission System Rates CRSP Management Center interest rates Falcon-Amistad Power Rates Provo River Power Rates Rio Grande Power Rates Seedskadee Power Rates SLCA/IP Power Rates Rate Schedules & Supplemental Rate Information Current Rates for Firm Power, Firm & Non-firm Transmission Service, & Ancillary Services Current Transmission & Ancillary Services Rates Tariffs Components of the SLCA/IP Existing Firm Power Rate Cost Recovery Charge (CRC) Page MOA Concerning the Upper Colorado River Basin

244

COSMIC RAY HEATING OF THE WARM IONIZED MEDIUM  

SciTech Connect (OSTI)

Observations of line ratios in the Milky Way's warm ionized medium suggest that photoionization is not the only heating mechanism present. For the additional heating to explain the discrepancy, it would have to have a weaker dependence on the gas density than the cooling rate, {Lambda}n{sub e}{sup 2}. Reynolds et al. suggested turbulent dissipation or magnetic field reconnection as possible heating sources. We investigate here the viability of MHD-wave mediated cosmic ray heating as a supplemental heating source. This heating rate depends on the gas density only through its linear dependence on the Alfven speed, which goes as n{sub e}{sup -1/2}. We show that, scaled to appropriate values of cosmic ray energy density, cosmic ray heating can be significant. Furthermore, this heating is stable to perturbations. These results should also apply to warm ionized gas in other galaxies.

Wiener, Joshua; Peng Oh, S. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States)] [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Zweibel, Ellen G. [Departments of Astronomy and Physics, and Center for Magnetic Self-Organization, University of Wisconsin-Madison, Madison, WI 53706 (United States)] [Departments of Astronomy and Physics, and Center for Magnetic Self-Organization, University of Wisconsin-Madison, Madison, WI 53706 (United States)

2013-04-10T23:59:59.000Z

245

Estimate sequence methods: extensions and approximations  

E-Print Network [OSTI]

Aug 11, 2009 ... Estimate sequence methods: extensions and approximations ... or both, and draw some guidelines on the design of further estimate sequence ...

Michel Baes

2009-08-11T23:59:59.000Z

246

Born-Oppenheimer approximation in open systems  

E-Print Network [OSTI]

We generalize the standard Born-Oppenheimer approximation to the case of open quantum systems. We define the zeroth order Born-Oppenheimer approximation of an open quantum system as the regime in which its effective Hamiltonian can be diagonalized with fixed slowly changing variables. We then establish validity and invalidity conditions for this approximation for two kinds of dissipations--the spin relaxation and the dissipation of center-of-mass motion. As an example, the Born-Oppenheimer approximation of a two-level open system is analyzed.

X. L. Huang; X. X. Yi

2009-09-16T23:59:59.000Z

247

Born-Oppenheimer approximation in open systems  

Science Journals Connector (OSTI)

We generalize the standard Born-Oppenheimer approximation to the case of open quantum systems. We define the zeroth-order Born-Oppenheimer approximation for an open quantum system as the regime in which its effective Hamiltonian can be diagonalized with fixed slowly changing variables. We then establish validity and invalidity conditions for this approximation for two types of dissipations—the spin relaxation and the dissipation of center-of-mass motion. As an example, the Born-Oppenheimer approximation for a two-level open system is analyzed.

X. L. Huang and X. X. Yi

2009-09-11T23:59:59.000Z

248

Resonances and the thermonuclear reaction rate  

E-Print Network [OSTI]

We present an approximate analytic expression for thermonuclear reaction rate of charged particles when the cross section contains a single narrow or wide resonance described by a Breit-Wigner shape. The resulting expression is uniformly valid as the effective energy and resonance energy coalesce. We use our expressions to calculate the reaction rate for $^{12}$C(p,$\\gamma$)$^{13}$N.

M. S. Hussein; M. Ueda; A. J. Sargeant; M. P. Pato

2003-07-21T23:59:59.000Z

249

Isothermal heat measurements of TBP-nitric acid solutions  

SciTech Connect (OSTI)

Net heats of reaction were measured in an isothermal calorimeter for both single phase (organic) and two phase (organic and aqueous) TBP/HNO{sub 3} reacting solutions at temperatures above 100 C. The oxidation rate constant was determined to be 5.4E-4 min{sup {minus}1} at 110 C for an open ``vented`` system as compared to 1.33 E-3 min{sup {minus}1} in the closed system. The heat released per unit material oxidized was also reduced. The oxidation in both phases was found to be first order in nitric acid and pseudo-zero order in butylnitrate and water. The hydrolysis (esterification) rate constant determined by Nichols` (1.33E-3 min{sup {minus}1}) fit the experimental data from this work well. Forced evaporation of the volatile components by the product gases from oxidation resulted in a cooling mechanism which more than balanced the heat from the oxidation reaction in the two-phased systems. Rate expressions were derived and rate constants determined for both the single and two phase systems. An approximating mathematical model was developed to fit the experimental data and to extrapolate beyond the experimental conditions. This model shows that one foot of ``reacting`` 14.3M HNO{sub 3} aqueous phase solution at 121 C will transport sufficient water to the organic phase to replace evaporative losses, maintaining endothermicity, for organic layers up to 12.2 + 6.0 feet deep. If the pressure in a reacting system is allowed to increase due to insufficient venting the temperature of the organic phase would increase in temperature to reach a new equilibrium. The rate of oxidation would increase not only due to the increase in temperature but also from the increased concentration of dissolved HNO{sub 3} reduction products. Another important factor is that the cooling system described in this work becomes less effective as the total pressure increases. These factors probably contributed to the explosion at Tomsk.

Smith, J.R.; Cavin, W.S.

1994-12-16T23:59:59.000Z

250

Validity of several approximations for the turbulent buoyant jet in a stagnant neutrally-stratified ambient  

SciTech Connect (OSTI)

A series of approximations are usually made in deriving integral model equations for the dispersion of a round turbulent buoyant jet into a stagnant neutrally-stratified ambient fluid. The magnitudes of differences in model predictions caused by making four of these approximations are calculated as a function of the initial densimetric Froude number and the initial relative density difference. The four approximations studied are (1) the Boussinesq approximation, (2) the use of a common Gaussian width for both mean axial velocity and mean temperature (or concentration) excess, (3) the neglect of fluctuation-correlation terms, and (4) the assumption of a linear relationship between excess density and excess temperature (or concentration). The four approximations are studied singly and then cumulatively as the predictions of the two models, one with and one without all approximations, are compared to seven low Froude number data cases. Results show that the Boussinesq approximation produces percentage differences in predictions which are about half of the initial relative density difference expressed in percentage. Use of a common Gaussian width for velocity and temperature produces differences from 6% to 30% depending on the entrainment assumption used. Fluctuation correlation effects rarely exceed 8%. Lastly, at Froude numbers below about 10 the correct nonlinear equation of state must often be used for heated waste jets to acheive accurate results, and the correct air equation of state may also be needed for low Froude number heated air jets, depending on the initial diameter and velocity.

Ponce, T.C.

1982-01-01T23:59:59.000Z

251

Rotary magnetic heat pump  

DOE Patents [OSTI]

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.

Kirol, L.D.

1987-02-11T23:59:59.000Z

252

Thulium-170 heat source  

SciTech Connect (OSTI)

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.

Walter, C.E.; Van Konynenburg, R.; VanSant, J.H.

1990-09-06T23:59:59.000Z

253

Thulium-170 heat source  

DOE Patents [OSTI]

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.

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

1992-01-01T23:59:59.000Z

254

Heat Treating Apparatus  

DOE Patents [OSTI]

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.

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

2002-09-10T23:59:59.000Z

255

Multiple pollutant removal using the condensing heat exchanger: Phase 1 final report, November 1995--June 1997. Addendum 2: Task 3 topical report -- Long term wear test  

SciTech Connect (OSTI)

Long-term operation of a condensing heat exchanger under typical coal-fired flue gas conditions was investigated in Phase 1, Task 3 of the Multiple Pollutant Removal Using the Condensing Heat Exchanger test program. The specific goal of this task was to determine the amount of wear, if any, on the Teflon{reg_sign}-covered heat transfer tubes in a condensing heat exchanger. A pilot-scale single-stage condensing heat exchanger (CHX{reg_sign}) was operated under typical coal-fired flue gas conditions on a continuous basis for a period of approximately 10 months. Operating conditions and particulate loadings for the test unit were monitored, Teflon{reg_sign} film thickness measurements were conducted, and surface replications (which duplicate the surface finish at the microscopic level) were taken at various times during the test. Data from the test indicate that virtually no decrease in Teflon{reg_sign} thickness was observed for the coating on the first two rows of heat exchanger tubes, even at high inlet particulate loadings (400 mg/dscm [0.35 lb/10{sup 6} Btu]). Evidence of wear was present only at the microscopic level, and even then was very minor in severity. Operation at high inlet particulate loadings resulted in accumulated ash deposits within the heat exchanger. Installation of a modified (higher flow rate) wash nozzle manifold substantially reduced subsequent deposit formation.

Kudlac, G.A.

1998-06-01T23:59:59.000Z

256

Radiative heating of the ISCCP upper level cloud regimes and its impact on the large-scale tropical circulation  

E-Print Network [OSTI]

Radiative heating of the ISCCP upper level cloud regimes and its impact on the large-scale tropical 2012; accepted 14 December 2012; published 31 January 2013. [1] Radiative heating profiles. The resulting radiative heating profiles have maxima of approximately 1 K/day near 12 km, with equal heating

257

Solar heat collector  

SciTech Connect (OSTI)

An evacuated double-tubing solar heat collector is described comprising: an inner tube having an open end and a closed end; a selective absorption film applied over an exterior surface of the inner tube; an outer tube having an open end and a closed end; the inner tube being constructed to be received within the outer tube; and a substantially continuous annular coil spring ring being substantially found in cross section and of a predetermined thickness. The coil spring ring is disposed between and engages an interior surface of the outer tube and the exterior surface of the inner tube for spacing and resiliently supporting the inner tube relative to the outer tube. The ring is freely rotatably positioned to be moved axially along the length of the inner tube due only to frictional forces exerted on the coil spring. The coil spring ring is positioned on the inner tube at approximately a middle position along the length of the inner tube by being initially positioned on the inner tube adjacent to the closed end thereof and rotated upon itself axially along the inner tube only by frictional engagement with the interior surface of the outer tube as the inner tube is inserted into the open end of the outer tube and moved to a fully inserted position within the outer tube. The open end of the inner tube and the open end of the outer tube are fused to form a junction and hermetically sealed.

Takeuchi, H.; Mikiya, T.

1987-03-17T23:59:59.000Z

258

Constructal multi-scale package of vertical channels with natural convection and maximal heat transfer density. CONSTRUCTAL DESIGN: THE GENERATION OF MULTI-SCALE HEAT  

E-Print Network [OSTI]

transfer density. CONSTRUCTAL DESIGN: THE GENERATION OF MULTI-SCALE HEAT AND FLUID FLOW STRUCTURES-scale structures in natural convection with the objective of maximizing the heat transfer density, or the heat transfer rate per unit of volume§ . The flow volume is filled with vertical equidistant heated blades

Kihm, IconKenneth David

259

CharacteristicGalerkin and Mixed Finite Element Approximation of Contamination by Compressible  

E-Print Network [OSTI]

Characteristic­Galerkin and Mixed Finite Element Approximation of Contamination by Compressible­disposal contamination in porous media is modeled by a coupled system of partial differential equations for the brine, radionuclides, and heat and by a mixed finite element method for the pressure and velocity

Chou, So-Hsiang

260

Delivery Cost Approximations for Inventory Routing Problems in a Rolling Horizon Framework  

E-Print Network [OSTI]

Delivery Cost Approximations for Inventory Routing Problems in a Rolling Horizon Framework Patrick Research Program, grant ARP-003 1 #12;Abstract The inventory routing problem considered in this paper is concerned with the repeated distribution of a commodity, such as heating oil, over a long period of time

Jaillet, Patrick

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Force approximation for a plasma actuator operating in atmospheric air Kunwar Pal Singh and Subrata Roya  

E-Print Network [OSTI]

Force approximation for a plasma actuator operating in atmospheric air Kunwar Pal Singh and Subrata to the actuator, dielectric heating, and power required to maintain the atmospheric pressure plasma during Roya Computational Plasma Dynamics Laboratory and Test Facility, Department of Mechanical and Aerospace

Roy, Subrata

262

Thermoelectric heat exchange element  

DOE Patents [OSTI]

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.

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

2007-08-14T23:59:59.000Z

263

The Observer Algorithm for Visibility Approximation  

E-Print Network [OSTI]

other algorithms do. We test this algorithm in several settings: rural, mountainous and urban areasThe Observer Algorithm for Visibility Approximation Per-Magnus OLSSON a and Patrick DOHERTY present a novel algorithm for visibility approximation that is sub- stantially faster than ray casting

Doherty, Patrick

264

APPROXIMATE TAXI FARES From Midway -$35  

E-Print Network [OSTI]

APPROXIMATE TAXI FARES From Midway - $35 From O'Hare - $60 From Downtown - $35 MIDWAY Midway International Airport is approximately eight miles west of the University of Chicago campus. Midway is easily transportation, shuttle, car, and taxi. FROM MIDWAY AIRPORT Follow the airport signs to the CTA Orange Line

Issa, Naoum

265

Optimal Tree Approximation with Wavelets Richard Baraniuk  

E-Print Network [OSTI]

simply represented: the energy from a singularity localizes along one branch of the tree (see Figure 1Optimal Tree Approximation with Wavelets Richard Baraniuk Department of Electrical and Computer on trees and point out that an optimal tree approximant exists and is easily computed. The optimal tree

266

Rough Set Approximations in Formal Concept Analysis  

E-Print Network [OSTI]

Rough Set Approximations in Formal Concept Analysis Yiyu Yao and Yaohua Chen Department of Computer}@cs.uregina.ca Abstract. A basic notion shared by rough set analysis and formal concept anal- ysis is the definability to each other based on defin- ability. In this paper, the notion of rough set approximations is introduced

Yao, Yiyu

267

Heat Integrate Heat Engines in Process Plants  

E-Print Network [OSTI]

and refrigeration systems. In many instances these real heat engines may appear as a complex process consisting of flash vessels, heat exchangers, compressors, furnaces, etc. See Figure 18a, which shows a simplified diagram of a "steam Rankine cycle." How... and rejection profiles of the real machine. For example, the heat acceptance and re jection profiles for the steam Rankine cycle shown in Figure 18a have been drawn on T,H coordinates in Figure 18b. Thus providing we know the heat acceptance and rejection...

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

268

Neutron imaging of alkali metal heat pipes  

SciTech Connect (OSTI)

High-temperature heat pipes are two-phase, capillary driven heat transfer devices capable of passively providing high thermal fluxes. Such a device using a liquid-metal coolant can be used as a solution for successful thermal management on hypersonic flight vehicles. Imaging of the liquid-metal coolant inside will provide valuable information in characterizing the detailed heat and mass transport. Neutron imaging possesses an inherent advantage from the fact that neutrons penetrate the heat pipe metal walls with very little attenuation, but are significantly attenuated by the liquid metal contained inside. Using the BT-2 beam line at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland, preliminary efforts have been conducted on a nickel-sodium heat pipe. The contrast between the attenuated beam and the background is calculated to be approximately 3%. This low contrast requires sacrifice in spatial or temporal resolution so efforts have since been concentrated on lithium (Li) which has a substantially larger neutron attenuation cross section. Using the CG-1D beam line at the High Flux Isotope Reactor (HFIR) of Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, the first neutron images of high-temperature molybdenum (Mo)-Li heat pipes have been achieved. The relatively high neutron cross section of Li allows for the visualization of the Li working fluid inside the heat pipes. The evaporator region of a gravity assisted cylindrical heat pipe prototype 25 cm long was imaged from start-up to steady state operation up to approximately 900 C. In each corner of the square bore inside, the capillary action raises the Li meniscus above the bulk Li pool in the evaporator region. As the operational temperature changes, the meniscus shapes and the bulk meniscus height also changes. Furthermore, a three-dimensional tomographic image is also reconstructed from the total of 128 projection images taken 1.4o apart in which the Li had already cooled and solidified.

Kihm, Ken [University of Tennessee, Knoxville (UTK); Kirchoff, Eric [University of Tennessee, Knoxville (UTK); Golden, Matt [University of Tennessee, Knoxville (UTK); Rosenfeld, J. [Thermacore Inc.; Rawal, S. [Lockheed Martin Space Systems Company; Pratt, D. [United States Air Force Research Laboratory, Wright-Patterson Air Force Base; Bilheux, Hassina Z [ORNL; Walker, Lakeisha MH [ORNL; Voisin, Sophie [ORNL; Hussey, Dan [NIST Center for Neutron Research (NCRN), Gaithersburg, MD

2013-01-01T23:59:59.000Z

269

Numerical and experimental investigation of buoyancy effects in a plate heat exchanger  

Science Journals Connector (OSTI)

This paper presents an experimental and numerical investigation of the hydrodynamic and thermal fields in a two-channel chevron-type plate heat exchanger (PHE) under mixed convection conditions. Eight pairs of experiments were performed, with water on both sides, with Reynolds number varying between approximately 100 and 400. Each pair consisted of two experiments: one with aiding mixed convection and the other with opposing mixed convection conditions. The temperature distributions on the end-plates, the outlet temperatures, the heat flux and the Nusselt number obtained in the two positions of the PHE were compared. A validation of the numerical model in this flow regime has been made in order to analyze numerically the pressure losses and the flow structure. Comparisons of the experimental data obtained for the fluid outlet temperatures, heat transfer rate and Nusselt number showed that the heat transfer is improved under aiding mixed convection conditions. The numerical data analysis shows that opposing mixed convection deteriorates the symmetry of the flow distribution inside the PHE's channels and that aiding buoyancy forces cause higher pressure losses.

Iulian Gherasim; Matthew Taws; Nicolas Galanis; Cong Tam Nguyen

2013-01-01T23:59:59.000Z

270

ACCURATE CALCULATIONS OF HEAT RELEASE IN FIRES S. Brohez', C. Delvosalle', G. Marlair2  

E-Print Network [OSTI]

values of the heat of combustion per unit mass of oxygen consumed and carbon dioxide generated are used calorimetry states that heat of complete combustion per unit mass of oxygen consumed is approximately constant an average value of the heat of combustion to be 13.1 Id per gram of oxygen consumed with a ± 5% variation

Paris-Sud XI, Université de

271

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

E-Print Network [OSTI]

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

Boyer, Edmond

272

System Modeling of Gas Engine Driven Heat Pump  

SciTech Connect (OSTI)

To improve the system performance of the GHP, modeling and experimental study has been made by using desiccant system in cooling operation (particularly in high humidity operations) and suction line waste heat recovery to augment heating capacity and efficiency. The performance of overall GHP system has been simulated by using ORNL Modulating Heat Pump Design Software, which is used to predict steady-state heating and cooling performance of variable-speed vapor compression air-to-air heat pumps for a wide range of operational variables. The modeling includes: (1) GHP cycle without any performance improvements (suction liquid heat exchange and heat recovery) as a baseline (both in cooling and heating mode), (2) the GHP cycle in cooling mode with desiccant system regenerated by waste heat from engine incorporated, (3) GHP cycle in heating mode with heat recovery (recovered heat from engine). According to the system modeling results, by using desiccant system regenerated by waste heat from engine, the SHR can be lowered to 40%. The waste heat of the gas engine can boost the space heating efficiency by 25% in rated operating conditions.

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

2012-01-01T23:59:59.000Z

273

Heating Cooling Flows with Weak Shock Waves  

E-Print Network [OSTI]

The discovery of extended, approximately spherical weak shock waves in the hot intercluster gas in Perseus and Virgo has precipitated the notion that these waves may be the primary heating process that explains why so little gas cools to low temperatures. This type of heating has received additional support from recent gasdynamical models. We show here that outward propagating, dissipating waves deposit most of their energy near the center of the cluster atmosphere. Consequently, if the gas is heated by (intermittent) weak shocks for several Gyrs, the gas within 30-50 kpc is heated to temperatures that far exceed observed values. This heating can be avoided if dissipating shocks are sufficiently infrequent or weak so as not to be the primary source of global heating. Local PV and viscous heating associated with newly formed X-ray cavities are likely to be small, which is consistent with the low gas temperatures generally observed near the centers of groups and clusters where the cavities are located.

W. G. Mathews; A. Faltenbacher; F. Brighenti

2005-11-05T23:59:59.000Z

274

Heat transfer system  

DOE Patents [OSTI]

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.

McGuire, Joseph C. (Richland, WA)

1982-01-01T23:59:59.000Z

275

Wound tube heat exchanger  

DOE Patents [OSTI]

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.

Ecker, Amir L. (Duncanville, TX)

1983-01-01T23:59:59.000Z

276

Heat Exchangers for Solar Water Heating Systems | Department of Energy  

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

Heat Exchangers for Solar Water Heating Systems Heat Exchangers for Solar Water Heating Systems Heat Exchangers for Solar Water Heating Systems May 30, 2012 - 3:40pm Addthis 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, because it is a good thermal conductor and has greater resistance to corrosion. Types of Heat Exchangers Solar water heating systems use three types of heat exchangers: Liquid-to-liquid A liquid-to-liquid heat exchanger uses a heat-transfer fluid that

277

Dynamics of heat transfer between nano systems  

E-Print Network [OSTI]

We develop a dynamical theory of heat transfer between two nano systems. In particular, we consider the resonant heat transfer between two nanoparticles due to the coupling of localized surface modes having a finite spectral width. We model the coupled nanosystem by two coupled quantum mechanical oscillators, each interacting with its own heat bath, and obtain a master equation for the dynamics of heat transfer. The damping rates in the master equation are related to the lifetimes of localized plasmons in the nanoparticles. We study the dynamics towards the steady state and establish connection with the standard theory of heat transfer in steady state. For strongly coupled nano particles we predict Rabi oscillations in the mean occupation number of surface plasmons in each nano particle.

Svend-Age Biehs; Girish S. Agarwal

2012-10-18T23:59:59.000Z

278

Cryogenic heat exchanger with turbulent flows  

Science Journals Connector (OSTI)

An evaporator-type cryogenic heat exchanger is designed and built for introducing fluid–solid heat exchange phenomena to undergraduates in a practical and efficient way. The heat exchanger functions at liquid nitrogen temperature and enables cooling of N2 and He gases from room temperatures. We present first the experimental results of various parameters which characterize the heat exchanger (efficiency, number of transfer units, heat exchange coefficient, etc) as a function of the mass flow rate of the gas to be cooled. An analysis of the Nu–Re diagram is also presented. All experiments were conducted with N2 gas. The scope of this tool is readily extended to research purposes.

Jay Amrit; Christelle Douay; Francis Dubois; Gérard Defresne

2012-01-01T23:59:59.000Z

279

Control system for fluid heated steam generator  

DOE Patents [OSTI]

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

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

1984-05-29T23:59:59.000Z

280

PSNC Energy (Gas) - Green Building Rate Discount | Department of Energy  

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

PSNC Energy (Gas) - Green Building Rate Discount PSNC Energy (Gas) - Green Building Rate Discount PSNC Energy (Gas) - Green Building Rate Discount < Back Eligibility Commercial Residential Savings Category Heating & Cooling Home Weatherization Construction Commercial Weatherization Commercial Heating & Cooling Design & Remodeling Solar Lighting Windows, Doors, & Skylights Heating Buying & Making Electricity Water Heating Wind Program Info State North Carolina Program Type Utility Rate Discount Rebate Amount $0.05 discount/therm Provider PSNC Energy This discounted rate is available to commercial customers whose building meets the U.S. Green Building Council's Leadership in Energy and Environmental Design (LEED) certification or equivalent. To qualify, the customer must be on the Rate 125. Qualifying customers pay $.05 per therm

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

HEATING 7. 1 user's manual  

SciTech Connect (OSTI)

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.

Childs, K.W.

1991-07-01T23:59:59.000Z

282

Expert Meeting Report: Exploring the Disconnect Between Rated and Field  

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

Exploring the Disconnect Between Rated and Exploring the Disconnect Between Rated and Field Performance of Water Heating Systems Expert Meeting Report: Exploring the Disconnect Between Rated and Field Performance of Water Heating Systems 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

283

Solar heating for indoor community swimming pool  

SciTech Connect (OSTI)

This project demonstrates the application of solar technology to an existing public indoor swimming pool. An application makes use of a new type of solar collector material called SolaRoll. The pool water is cycled through collectors made of the material mounted on the pool's dome roof, reducing reliance on natural gas and fuel oil. Approximately 60% of the energy to heat pool water will be provided. The specific objective of the project is to reduce reliance on natural gas and fuel oil consumption used to heat the community's pool and in so doing provide an example for residential applications.

Not Available

1984-01-01T23:59:59.000Z

284

Surface-induced heating of cold polar molecules  

E-Print Network [OSTI]

We study the rotational and vibrational heating of diatomic molecules placed near a surface at finite temperature on the basis of macroscopic quantum electrodynamics. The internal molecular evolution is governed by transition rates that depend on both temperature and position. Analytical and numerical methods are used to investigate the heating of several relevant molecules near various surfaces. We determine the critical distances at which the surface itself becomes the dominant source of heating and we investigate the transition between the long-range and short-range behaviour of the heating rates. A simple formula is presented that can be used to estimate the surface-induced heating rates of other molecules of interest. We also consider how the heating depends on the thickness and composition of the surface.

Stefan Yoshi Buhmann; M. R. Tarbutt; Stefan Scheel; E. A. Hinds

2008-06-18T23:59:59.000Z

285

RADIATIVE HEATING OF THE SOLAR CORONA  

SciTech Connect (OSTI)

We investigate the effect of solar visible and infrared radiation on electrons in the Sun's atmosphere using a Monte Carlo simulation of the wave-particle interaction and conclude that sunlight provides at least 40% and possibly all of the power required to heat the corona, with the exception of dense magnetic flux loops. The simulation uses a radiation waveform comprising 100 frequency components spanning the solar blackbody spectrum. Coronal electrons are heated in a stochastic manner by low coherence solar electromagnetic radiation. The wave 'coherence time' and 'coherence volume' for each component is determined from optical theory. The low coherence of solar radiation allows moving electrons to gain energy from the chaotic wave field which imparts multiple random velocity 'kicks' to these particles causing their velocity distribution to broaden or heat. Monte Carlo simulations of broadband solar radiative heating on ensembles of 1000 electrons show heating at per particle levels of 4.0 x 10{sup -21} to 4.0 x 10{sup -20} W, as compared with non-loop radiative loss rates of {approx}1 x 10{sup -20} W per electron. Since radiative losses comprise nearly all of the power losses in the corona, sunlight alone can explain the elevated temperatures in this region. The volume electron heating rate is proportional to density, and protons are assumed to be heated either by plasma waves or through collisions with electrons.

Moran, Thomas G., E-mail: moran@grace.nascom.nasa.gov [Physics Department, Catholic University of America, 200 Hannan Hall, Washington, DC 20064 (United States) and NASA/GSFC, Code 671, Greenbelt, MD 20771 (United States)

2011-10-20T23:59:59.000Z

286

Approximate Stokes Drift Profiles in Deep Water  

Science Journals Connector (OSTI)

A deep-water approximation of the Stokes drift velocity profile is explored as an alternative to the monochromatic profile. The alternative profile investigated relies on the same two quantities required for the monochromatic profile, namely, the ...

Øyvind Breivik; Peter A. E. M. Janssen; Jean-Raymond Bidlot

2014-09-01T23:59:59.000Z

287

Quasiclassical Approximation for Slow Neutron Scattering  

Science Journals Connector (OSTI)

......Approximation for Slow Neutron Scattering Takeo Nishigori Department...formula for the differential scattering cross section of a slow neutron is derived along the line...of Spherical Rotors and Neutron Scattering Juichiro Hama and Tuto......

Takeo Nishigori

1970-06-01T23:59:59.000Z

288

Rough Approximate Operators: Axiomatic Rough Set Theory  

Science Journals Connector (OSTI)

In rough set theory, the upper and lower approximations are ... are two abstract operators acting on the power set of U, the universe of discourse. ... The proof is an easy application of point set topology. Simi...

T. Y. Lin; Qing Liu

1994-01-01T23:59:59.000Z

289

On the Born-Oppenheimer approximation  

Science Journals Connector (OSTI)

We discuss the validity of the Born-Oppenheimer approximation for molecular levels. It is shown...1/4...and prescriptions are given for their calculation. In particular to fourth order some adiabatic corrections ...

J. M. Combes

1975-01-01T23:59:59.000Z

290

NONLINEAR APPROXIMATIONS FOR ELECTRONIC STRUCTURE CALCULATIONS  

E-Print Network [OSTI]

NONLINEAR APPROXIMATIONS FOR ELECTRONIC STRUCTURE CALCULATIONS G. BEYLKIN AND T. S. HAUT Abstract. We present a new method for electronic structure calculations based on novel algorithms for nonlinear numerical calculus suitable for electronic structure calculations. For any spatial orbital

Beylkin, Gregory

291

Approximate inference in Gaussian graphical models  

E-Print Network [OSTI]

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

Malioutov, Dmitry M., 1981-

2008-01-01T23:59:59.000Z

292

A fresh look at the adhesion approximation  

E-Print Network [OSTI]

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

Thomas Buchert

1997-11-04T23:59:59.000Z

293

Geothermal Heat Pumps  

Broader source: Energy.gov [DOE]

The Geothermal Technologies Office focuses only on electricity generation. For additional information about geothermal heating and cooling and ground source heat pumps, please visit the U.S. Department of Energy (DOE)'s Buildings Technologies Office.

294

HEAT TRANSFER FLUIDS  

E-Print Network [OSTI]

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

Lenert, Andrej

2012-01-01T23:59:59.000Z

295

Residential heating oil price  

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

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...

296

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...

297

Residential heating oil price  

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

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...

298

Residential heating oil price  

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

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...

299

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.

300

Ductless Heat Pumps  

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

Water Heaters Showerheads Residential Weatherization Performance Tested Comfort Systems Ductless Heat Pumps New Construction Residential Marketing Toolkit Retail Sales...

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Heat Pump Water Heaters  

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

Water Heaters Showerheads Residential Weatherization Performance Tested Comfort Systems Ductless Heat Pumps New Construction Residential Marketing Toolkit Retail Sales...

302

Solar heat receiver  

DOE Patents [OSTI]

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.

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

1982-09-29T23:59:59.000Z

303

Electric resistive space heating  

Science Journals Connector (OSTI)

The cost of heating residential buildings using electricity is compared to the cost employing gas or oil. (AIP)

David Bodansky

1985-01-01T23:59:59.000Z

304

An improved proximity force approximation for electrostatics  

SciTech Connect (OSTI)

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.

Fosco, Cesar D. [Centro Atomico Bariloche, Comision Nacional de Energia Atomica, R8402AGP Bariloche (Argentina) [Centro Atomico Bariloche, Comision Nacional de Energia Atomica, R8402AGP Bariloche (Argentina); Instituto Balseiro, Universidad Nacional de Cuyo, R8402AGP Bariloche (Argentina); Lombardo, Fernando C. [Departamento de Fisica Juan Jose Giambiagi, FCEyN UBA, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina) [Departamento de Fisica Juan Jose Giambiagi, FCEyN UBA, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina); IFIBA (Argentina)] [Argentina; Mazzitelli, Francisco D., E-mail: fdmazzi@cab.cnea.gov.ar [Centro Atomico Bariloche, Comision Nacional de Energia Atomica, R8402AGP Bariloche (Argentina); Departamento de Fisica Juan Jose Giambiagi, FCEyN UBA, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina)

2012-08-15T23:59:59.000Z

305

Extended quasiparticle approximation and Brueckner theory  

Science Journals Connector (OSTI)

The time-dependent Green’s function method provides a basic theory for nuclear dynamics and heavy-ion collisions. The spectral function plays an important role in this theory containing information on correlations in the medium. These are usually neglected by using a quasiparticle approximation. In order to evaluate this particular approach it is important to establish in the static limit a link between this method and other traditional nuclear many-body theories such as the Brueckner approach. Using a self-consistent T-matrix approximation for the self-energy in the Green’s-function approach, treating particles and holes on equal footing, the self-energy can be obtained and compared with the Brueckner expression. In the quasiparticle limit it contains terms up to and analogous to the Brueckner second order rearrangement energy. In an extended quasiparticle approximation (EQP) which does not violate the sum rule for the spectral function the Brueckner third-order rearrangement energy can also be reproduced. The latter approximation constitutes a bridge between the Brueckner and Green’s-function methods. It assumes small absorption (and energy dependence) of the mean field. Some numerical estimates of the different approximation schemes that we discuss are shown. An iteration scheme for applying the EQP approximation is suggested.

H. S. Köhler and Rudi Malfliet

1993-09-01T23:59:59.000Z

306

CYCLOTRON HEATING NFR THE MULTIPOLE B = 0 AXIS J. C. Sprott  

E-Print Network [OSTI]

CYCLOTRON HEATING NFR THE MULTIPOLE B = 0 AXIS by J. C. Sprott November 1973 PLP 536 Plasma Studies of the author and major professor. #12;Ion and Electron Cyclotron heating rates in multipoles are generally = 0 axis in a multipole. The average cyclotron heating rate is given by d--= dt where TIB G 0 = TI

Sprott, Julien Clinton

307

Liquid heat capacity lasers  

DOE Patents [OSTI]

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.

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

2007-05-01T23:59:59.000Z

308

Heat Transfer Guest Editorial  

E-Print Network [OSTI]

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

Kandlikar, Satish

309

Acoustic Heating Peter Ulmschneider  

E-Print Network [OSTI]

Acoustic Heating Peter Ulmschneider lnstitut fiir Theoretische Astrophysik der Universitat waves are a viable and prevalent heating mechanism both in early- and in late-type stars. Acoustic heating appears to be a dominant mechanism for situations where magnetic fields are weak or absent

Ulmschneider, Peter

310

Ammoniated salt heat pump  

SciTech Connect (OSTI)

A thermochemical heat pump/energy storage system using liquid ammoniate salts is described. The system, which can be used for space heating or cooling, provides energy storage for both functions. The bulk of the energy is stored as chemical energy and thus can be stored indefinitely. The system is well suited to use with a solar energy source or industrial waste heat.

Haas, W.R.; Jaeger, F.J.; Giordano, T.J.

1981-01-01T23:59:59.000Z

311

Pioneering Heat Pump Project  

Broader source: Energy.gov [DOE]

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

312

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

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

DOE Announces Award of a Contract to Repurchase Heating Oil for the DOE Announces 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 Northeast Home Heating Oil Reserve (NEHHOR). The purchased oil is expected to be delivered to the Hess First Reserve terminal at Perth Amboy, NJ in New York Harbor later this week. The award resulted from a solicitation issued on June 23, 2008, to repurchase heating oil using $3 million in funds appropriated after the

313

Heat deliverability of homogeneous geothermal reservoirs  

SciTech Connect (OSTI)

For the last two decades, the petroleum industry has been successfully using simple inflow performance relationships (IPR's) to predict oil deliverability. In contrast, the geothermal industry lacked a simple and reliable method to estimate geothermal wells' heat deliverability. To address this gap in the standard geothermal-reservoir-assessment arsenal, we developed generalized dimensionless geothermal inflow performance relationships (GIPR's). These ''reference curves'' may be regarded as an approximate general solution of the equations describing the practically important case of radial 2-phase inflow. Based on this approximate solution, we outline a straightforward approach to estimate the reservoir contribution to geothermal wells heat and mass deliverability for 2-phase reservoirs. This approach is far less costly and in most cases as reliable as numerically modeling the reservoir, which is the alternative for 2-phase inflow.

Iglesias, Eduardo R.; Moya, Sara L.

1991-01-01T23:59:59.000Z

314

Home Heating | Department of Energy  

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

Home Heating Everything you need to know about home heating, including how heating systems work, the different types on the market and proper maintenance. Read more Thermostats...

315

Water Heating | Department of Energy  

Energy Savers [EERE]

Energy Saver Water Heating Water Heating Infographic: Water Heaters 101 Infographic: Water Heaters 101 Everything you need to know about saving money on water heating costs....

316

Sand Mountain Electric Cooperative - Residential Heat Pump Loan Program |  

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

Sand Mountain Electric Cooperative - Residential Heat Pump Loan Sand Mountain Electric Cooperative - Residential Heat Pump Loan Program Sand Mountain Electric Cooperative - Residential Heat Pump Loan Program < Back Eligibility Residential Savings Category Heating & Cooling Commercial Heating & Cooling Heat Pumps Program Info State Alabama Program Type Utility Loan Program Rebate Amount 7% interest rate 5 or 10 year pay schedule maximum of $12,000 Provider Sand Mountain Electric Cooperative The Sand Mountain Electric Cooperative offers a heat pump loan program to eligible residential members. To qualify, members must have had power with Sand Mountain Electric Cooperative for at least one year, have the home electric bill and deeds in the same name, and pass a credit check. Heat pumps must be installed by a [http://www.smec.coop/heatpumpcontractors.htm

317

Intermountain Gas Company (IGC) - Gas Heating Rebate Program | Department  

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

Intermountain Gas Company (IGC) - Gas Heating Rebate Program Intermountain Gas Company (IGC) - Gas Heating Rebate Program Intermountain Gas Company (IGC) - Gas Heating Rebate Program < Back Eligibility Residential Savings Category Heating & Cooling Commercial Heating & Cooling Heating Program Info State Idaho Program Type Utility Rebate Program Rebate Amount Furnace: $200/unit Provider Customer Service The Intermountain Gas Company's (IGC) Gas Heating Rebate Program offers customers a $200 per unit rebate when they convert to a high efficiency natural gas furnace that replaces a heating system using another energy source. New furnaces must meet a minimum AFUE efficiency rating of 90%, and the home must have been built at least three years prior to the furnace conversion to qualify for the rebate. Visit IGC's program web site for more

318

Calculations of Heat-Capacities of Adsorbates  

E-Print Network [OSTI]

PHYSICAL REVIEW B VOLUME 14, NUMBER 7 1 OCTOBER 1976 Calculations of heat capacities of adsorbates W. R. Lawrence and R. E. Allen Department of Physics, Texas A& M University, College Station, Texas 77843 (Received 2 September 1975) The phonon... the substrate has a perfect (100) surface and the adsorbate goes down as a solid monolayer in registry with the substrate. The quasiharmonic approximation was used, and the results for Ne adsorbates were considerably different from those obtained...

LAWRENCE, WR; Allen, Roland E.

1976-01-01T23:59:59.000Z

319

Utility Rate Discounts | Open Energy Information  

Open Energy Info (EERE)

Discounts Discounts Jump to: navigation, search A few electric utilities offer rate discounts to encourage residential energy efficiency. For homes that meet certain energy efficiency criteria, such as those established by the federal Energy Star program, the owner or tenant is awarded a percentage discount on each monthÂ’s electric bill. [1] Contents 1 Utility Rate Discount Incentives 2 References Utility Rate Discount Incentives CSV (rows 1 - 14) Incentive Incentive Type Place Applicable Sector Eligible Technologies Active Cleco Power - Power Miser New Home Program (Louisiana) Utility Rate Discount Louisiana Residential Building Insulation Central Air conditioners Clothes Washers Comprehensive Measures/Whole Building Doors Duct/Air sealing Furnaces Heat pumps

320

Magnetars as cooling neutron stars with internal heating  

E-Print Network [OSTI]

We study thermal structure and evolution of magnetars as cooling neutron stars with a phenomenological heat source in a spherical internal layer. We explore the location of this layer as well as the heating rate that could explain high observable thermal luminosities of magnetars and would be consistent with the energy budget of neutron stars. We conclude that the heat source should be located in an outer magnetar's crust, at densities rho heat intensity of the order of 1e20 erg/s/cm^3. Otherwise the heat energy is mainly emitted by neutrinos and cannot warm up the surface.

A. D. Kaminker; D. G. Yakovlev; A. Y. Potekhin; N. Shibazaki; P. S. Shternin; O. Y. Gnedin

2006-05-18T23:59:59.000Z

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Residential Heating Oil Prices  

Gasoline and Diesel Fuel Update (EIA)

This chart highlights residential heating oil prices for the current and This chart highlights residential heating oil prices for the current and past heating season. As you can see, prices have started the heating season, about 40 to 50 cents per gallon higher than last year at this time. The data presented are from EIA's State Heating Oil and Propane Program. We normally collect and publish this data twice a month, but given the low stocks and high prices, we started tracking the prices weekly. These data will also be used to determine the price trigger mechanism for the Northeast Heating Oil Reserve. The data are published at a State and regional level on our web site. The slide is to give you some perspective of what is happening in these markets, since you probably will get a number of calls from local residents about their heating fuels bills

322

Active microchannel heat exchanger  

DOE Patents [OSTI]

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.

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

2001-01-01T23:59:59.000Z

323

Nanofluid heat capacities  

Science Journals Connector (OSTI)

Significant increases in the heat capacity of heat transfer fluids are needed not only to reduce the costs of liquid heating and cooling processes but also to bring clean energy producing technologies like concentrating solar power (CSP) to price parity with conventional energy generation. It has been postulated that nanofluids could have higher heat capacities than conventional fluids. In this work nano- and micron-sized particles were added to five base fluids (poly-? olefin mineral oil ethylene glycol a mixture of water and ethylene glycol and calcium nitrate tetrahydrate) and the resulting heat capacities were measured and compared with those of the neat base fluids and the weighted average of the heat capacities of the components. The particles used were inert metals and metal oxides that did not undergo any phase transitions over the temperature range studied. In the nanofluids studied here we found no increase in heat capacity upon the addition of the particles larger than the experimental error.

Anne K. Starace; Judith C. Gomez; Jun Wang; Sulolit Pradhan; Greg C. Glatzmaier

2011-01-01T23:59:59.000Z

324

A model for improvement of water heating heat exchanger designs for residential heat pump water heaters.  

E-Print Network [OSTI]

??Heat pump water heaters are a promising technology to reduce energy use and greenhouse gas emissions. A key component is the water heating heat exchanger.… (more)

Weerawoot, Arunwattana

2010-01-01T23:59:59.000Z

325

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

SciTech Connect (OSTI)

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.

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

2011-01-01T23:59:59.000Z

326

PERFORMANCE OF A STIRLING ENGINE POWERED HEAT ACTIVATED HEAT PUMP  

E-Print Network [OSTI]

PERFORMANCE OF A STIRLING ENGINE POWERED HEAT ACTIVATED HEAT PUMP W. D. C. Richards and W. L. Auxer General Electric Company Space Division King of Prussia, Pa. ABSTRACT A heat activated heat pump (HAHP for space heating since it directly utilizes the engine waste heat in addition to the energy obtained

Oak Ridge National Laboratory

327

Chlorite Dissolution Rates  

SciTech Connect (OSTI)

Spreadsheets provides measured chlorite rate data from 100 to 300C at elevated CO2. Spreadsheet includes derived rate equation.

Carroll, Susan

2013-07-01T23:59:59.000Z

328

Chlorite Dissolution Rates  

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

Spreadsheets provides measured chlorite rate data from 100 to 300C at elevated CO2. Spreadsheet includes derived rate equation.

Carroll, Susan

329

Impingement cooling and heat transfer measurement using transient liquid crystal technique  

E-Print Network [OSTI]

A heat transfer study on jet impingement cooling is presented. The study focuses on the effect of impingement jet flow rate, jet angle, and flow exit direction on various target surface heat transfer distributions. A two-channel test section...

Huang, Yizhe

2012-06-07T23:59:59.000Z

330

Anisotropic turbulent model for solar coronal heating  

E-Print Network [OSTI]

Context : We present a self-consistent model of solar coronal heating, originally developed by Heyvaert & Priest (1992), in which we include the dynamical effect of the background magnetic field along a coronal structure by using exact results from wave MHD turbulence (Galtier et al. 2000). Aims : We evaluate the heating rate and the microturbulent velocity for comparison with observations in the quiet corona, active regions and also coronal holes. Methods :The coronal structures are assumed to be in a turbulent state maintained by the slow erratic motions of the magnetic footpoints. A description for the large-scale and the unresolved small-scale dynamics are given separately. From the latter, we compute exactly (or numerically for coronal holes) turbulent viscosites that are finally used in the former to close self-consistently the system and derive the heating flux expression. Results : We show that the heating rate and the turbulent velocity compare favorably with coronal observations. Conclusions : Although the Alfven wave turbulence regime is strongly anisotropic, and could reduce a priori the heating efficiency, it provides an unexpected satisfactory model of coronal heating for both magnetic loops and open magnetic field lines.

B. Bigot; S. Galtier; H. Politano

2007-12-12T23:59:59.000Z

331

Power Rate Cases (pbl/rates)  

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

Choices (2003-06) Power Function Review (PFR) Firstgov Power Rate Cases BPA's wholesale power rates are set to recover its costs and repay the U.S. Treasury for the Federal...

332

High-rate HMDSO-based coatings in open air using atmospheric-pressure plasma jet  

Science Journals Connector (OSTI)

This work deals with the high-rate and dust-free formation of carbon-containing silicon oxide (SiOC) coatings in open air without substrate heating using an atmospheric-pressure (AP) plasma jet. The AP plasma was excited by a 13.56-MHz radio frequency (RF) power. Hexamethyldisiloxane and oxygen (O2) were used as the source gases. By optimizing the O2 flow rate and RF power, SiOC films were readily fabricated at deposition rates higher than 100 nm/s without suffering from particulate contaminations of the film surface. Additionally, an inorganic SiO2-like film exhibiting O/Si atomic ratio of approximately 2 was obtained at a deposition rate of ~ 13 nm/s, the value of which is still greater than those obtained in other AP plasma sources. Further systematic studies are needed to see if good-quality inorganic SiO2-like films can be obtained with higher rates.

H. Kakiuchi; K. Higashida; T. Shibata; H. Ohmi; T. Yamada; K. Yasutake

2012-01-01T23:59:59.000Z

333

Stochastic Approximation and Its Application in MCMC  

E-Print Network [OSTI]

) is known as observational noise, which is de ned as follows: t+1 = H t+1( t; xt+1) h t+1( t); In 1951, Robin and Monro introduced the so-called Robbins - Monro algorithm (1951) to solve the integration equation and the algorithm works as follows...: Algorithm 1.1.1. Stochastic Approximation 1 a. Generate Xt+1 g t(x), where t indexes the iteration. b. Set t+1 = t + atH( t; Xt+1), where at is the gain factor. This Robbins a^ Monro algorithm is the most popular stochastic approximation method used...

Cheng, Yichen

2013-05-31T23:59:59.000Z

334

Heat pump system  

DOE Patents [OSTI]

An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

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

1983-01-01T23:59:59.000Z

335

Analyzing the efficiency of a heat pump assisted drain water heat recovery system that uses a vertical inline heat exchanger  

Science Journals Connector (OSTI)

Abstract The purpose of the present study is to accumulate knowledge on how a drain water heat recovery system using a vertical inline heat exchanger and a heat pump performs under different drain water flow profile scenarios. Investigating how the intermittent behavior of the drain water influences the performance for this type of system is important because it gives insight on how the system will perform in a real life situation. The scenarios investigated are two 24 h drain water flow rate schedules and one shorter schedule representing a three minute shower. The results from the present paper add to the knowledge on how this type of heat recovery system performs in a setting similar to a multi-family building and how sizing influences the performance. The investigation shows that a heat recovery system of this type has the possibility to recover a large portion of the available heat if it has been sized to match the drain water profile. Sizing of the heat pump is important for the system performance; sizing of the storage tank is also important but not as critical.

Jörgen Wallin; Joachim Claesson

2014-01-01T23:59:59.000Z

336

Compressor Selection and Equipment Sizing for Cold Climate Heat Pumps  

SciTech Connect (OSTI)

In order to limit heating capacity degradation at -25 C (-13 F) ambient to 25%, compared to the nominal rating point capacity at 8.3 C (47 F), an extensive array of design and sizing options were investigated, based on fundamental equipment system modeling and building energy simulation. Sixteen equipment design options were evaluated in one commercial building and one residential building, respectively in seven cities. The energy simulation results were compared to three baseline cases: 100% electric resistance heating, a 9.6 HSPF single-speed heat pump unit, and 90% AFUE gas heating system. The general recommendation is that variable-speed compressors and tandem compressors, sized such that their rated heating capacity at a low speed matching the building design cooling load, are able to achieve the capacity goal at low ambient temperatures by over-speeding, for example, a home with a 3.0 ton design cooling load, a tandem heat pump could meet this cooling load running a single compressor, while running both compressors to meet heating load at low ambient temperatures in a cold climate. Energy savings and electric resistance heat reductions vary with building types, energy codes and climate zones. Oversizing a heat pump can result in larger energy saving in a less energy efficient building and colder regions due to reducing electric resistance heating. However, in a more energy-efficient building or for buildings in warmer climates, one has to consider balance between reduction of resistance heat and addition of cyclic loss.

Shen, Bo [ORNL] [ORNL; Abdelaziz, Omar [ORNL] [ORNL; Rice, C Keith [ORNL] [ORNL

2014-01-01T23:59:59.000Z

337

Gravitational wave heating of stars and accretion discs  

Science Journals Connector (OSTI)

......suppression of the heating rate if the forcing period...accretion discs. black hole physics|gravitational waves...the tidal disruption rate of stars due to the refilling...the medium that the GW passes through. The dissipation rate of the GW energy gives......

Gongjie Li; Bence Kocsis; Abraham Loeb

2012-10-01T23:59:59.000Z

338

Policies supporting Heat Pump Technologies  

E-Print Network [OSTI]

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

Oak Ridge National Laboratory

339

Bypass valve and coolant flow controls for optimum temperatures in waste heat recovery systems  

DOE Patents [OSTI]

Implementing an optimized waste heat recovery system includes calculating a temperature and a rate of change in temperature of a heat exchanger of a waste heat recovery system, and predicting a temperature and a rate of change in temperature of a material flowing through a channel of the waste heat recovery system. Upon determining the rate of change in the temperature of the material is predicted to be higher than the rate of change in the temperature of the heat exchanger, the optimized waste heat recovery system calculates a valve position and timing for the channel that is configurable for achieving a rate of material flow that is determined to produce and maintain a defined threshold temperature of the heat exchanger, and actuates the valve according to the calculated valve position and calculated timing.

Meisner, Gregory P

2013-10-08T23:59:59.000Z

340

On the efficient path integral evaluation of thermal rate constants within the quantum instanton approximation  

E-Print Network [OSTI]

an adaptive umbrella sampling can be used effectively to construct such a free energy surface. The overall computational procedure is illustrated by the application to a hydrogen exchange reaction in gas phase, which'' model.2 Though SC instanton methods have been widely used3­7 in chemistry and condensed matter physics

Miller, William H.

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Wastewater recycling and heat reclamation project: Red Lion Central Laundry, Portland, Oregon  

SciTech Connect (OSTI)

This report discusses water, energy, and cost savings that can be achieved in a commercial laundry through the use of a wastewater recycling and heat recovery system. Cost savings are achieved through reductions in water use, reduction in sewage charges (typically based on water use), reductions in water heating energy, and potential reductions in water treatment chemicals because the recycled water has already been treated with soaps and conditioners. A recovery system saves water by recycling wash water that would normally be dumped into the city sewage system. Recycling the wash water produces considerable energy savings because the recycled water has a higher temperature than fresh water. As a result, a hot water heater consumes less energy to heat the recycled water. The demonstration project discussed in this report was based in a large commercial laundry in Portland, Oregon. The laundry serves a large hotel/motel chain and processes an average of 25,000 pounds of laundry per day. A wastewater recovery system using a membrane microfiltration unit (MFU) was installed in the laundry in September 1995. Time series data of the water and energy consumption of the laundry were taken before and after installation of the MFU. Energy savings were measured by performing a thermal energy balance around the washing machines. Water savings were calculated by metering volumetric flow rates. After a period of approximately five months, the MFU has achieved final results of 52 percent savings in water consumption and 44 percent savings in energy to heat water. This five-month period represents a learning curve during which several small technical improvements were made to the MFU and laundry staff adjusted laundry operations to maximize the benefits of the MFU. An economic analysis discusses the impact of capital investment, daily consumption, and local utility rates on the payback period.

Garlick, T.F.; Halverson, M.A.; Ledbetter, M.R.

1997-06-01T23:59:59.000Z

342

Fluidized bed heat treating system  

DOE Patents [OSTI]

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

Ripley, Edward B; Pfennigwerth, Glenn L

2014-05-06T23:59:59.000Z

343

Radiative heat transfer in 2D Dirac materials  

E-Print Network [OSTI]

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

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

2015-02-02T23:59:59.000Z

344

Flameless heat generator  

SciTech Connect (OSTI)

A heating device generates heat by working a liquid in a closed container with a rotating stack of finely perforate square plates and recovering the heat from the thus heated liquid. In one embodiment a stack of a multiplicity of flat square plates radially offset one from another is rotated in an oil bath in a container under an inner perforate non-rotating cover over which is a similar non-rotating cover that is imperforate. The thermal energy developed through the mechanical working of the liquid is transferred to the main liquid bath and is then removed, as for example, by circulating air or a liquid around the outside of the container with the thus heated air or liquid being used to heat a house or the like.

Leary, C. L.; Leary, G. C.

1983-12-13T23:59:59.000Z

345

APPROXIMATION ALGORITHMS FOR CLUSTERING A Dissertation  

E-Print Network [OSTI]

develop new algorithmic techniques that will find application in a wide range of settings. We consider problems such as the stochastic versions of the set cover, vertex cover, and facility location problemsAPPROXIMATION ALGORITHMS FOR CLUSTERING PROBLEMS A Dissertation Presented to the Faculty

Swamy, Chaitanya

346

Symbolic Test Selection Based on Approximate Analysis  

E-Print Network [OSTI]

Symbolic Test Selection Based on Approximate Analysis Bertrand Jeannet, Thierry J´eron, Vlad Rusu}@irisa.fr Abstract. This paper addresses the problem of generating symbolic test cases for testing the conformance. The challenge we consider is the selection of test cases according to a test purpose, which is here a set

Paris-Sud XI, Université de

347

Approximate Relational Reasoning by Stochastic Propositionalization  

E-Print Network [OSTI]

Approximate Relational Reasoning by Stochastic Propositionalization Nicola Di Mauro, Teresa M fold recognition Nicola Di Mauro · Teresa M.A. Basile · Stefano Ferilli · Floriana Esposito Department.com c Springer-Verlag Berlin Heidelberg 2010 #12;82 N. Di Mauro et al. and drug design are relational

Di Mauro, Nicola

348

Correcting the diffusion approximation at the boundary  

E-Print Network [OSTI]

, 2011 The diffusion approximation to the radiative transport equation applies for light that has solutions of the radiative transport equation to evaluate each of their accuracy. Nonetheless, nearly all transport equation · I þ aI þ sLI ¼ 0; ð1:1� governs continuous light propagation in tissues [1

Kim, Arnold D.

349

Approximating the Permanent with Belief Propagation  

E-Print Network [OSTI]

, then use Bethe free energy to approximate this partition function. After deriving some speedups to standard, not to mention relatively high polynomial running times that discourage their usage in practical applications-connected networks such as trees. In certain special loopy graph cases, including graphs with a single loop

Huang, Bert

350

Approximated Distributions of Sampling Inequality Indices  

Science Journals Connector (OSTI)

Often, in finite samples, the true level of the confidence intervals for natural estimators of inequality indices belonging to the Gini family differs greatly from their nominal level, which is based on the asymptotic confidence limits. This paper ... Keywords: Gini index family, Gram-Charlier approximation, Monte Carlo experiment, algebraic computer software, income distribution

Paola Palmitesta; Corrado Provasi; Cosimo Spera

1999-06-01T23:59:59.000Z

351

Approximate Inference and Protein-Folding  

E-Print Network [OSTI]

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

Weiss, Yair

352

Waste Heat Management Options: Industrial Process Heating Systems  

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

Heat Management Options Heat Management Options Industrial Process Heating Systems By Dr. Arvind C. Thekdi E-mail: athekdi@e3minc.com E3M, Inc. August 20, 2009 2 Source of Waste Heat in Industries * Steam Generation * Fluid Heating * Calcining * Drying * Heat Treating * Metal Heating * Metal and Non-metal Melting * Smelting, agglomeration etc. * Curing and Forming * Other Heating Waste heat is everywhere! Arvind Thekdi, E3M Inc Arvind Thekdi, E3M Inc 3 Waste Heat Sources from Process Heating Equipment * Hot gases - combustion products - Temperature from 300 deg. F. to 3000 deg.F. * Radiation-Convection heat loss - From temperature source of 500 deg. F. to 2500 deg. F. * Sensible-latent heat in heated product - From temperature 400 deg. F. to 2200 deg. F. * Cooling water or other liquids - Temperature from 100 deg. F. to 180 deg. F.

353

A Nontoxic System for 41.8°C Whole-Body Hyperthermia: Results of a Phase I Study Using a Radiant Heat Device  

Science Journals Connector (OSTI)

...metabolic rate, volume of distribution, and individual drug...the neck. Evaporative heat loss from the head was minimized...to prevent evaporative heat losses. Following this, the...8 C was equal to the heat losses from the covered patient...

H. Ian Robins; Warren H. Dennis; Alan J. Neville; Linda M. Shecterle; Patricia A. Martin; Jeffrey Grossman; Thomas E. Davis; Susan R. Neville; Wilma K. Gillis; and Ben F. Rusy

1985-08-01T23:59:59.000Z

354

Numerical Studies of Fluid Leakage from a Geologic Disposal Reservoir for CO2 Show Self-Limiting Feedback between Fluid Flow and Heat Transfer  

E-Print Network [OSTI]

Feedback between Fluid Flow and Heat Transfer Karsten Pruessfeedback between fluid flow and heat transfer tends to limitfluid mobility (viscosity and relative permeability effects), are countered by effects arising from limitations in the rate of conductive heat transfer.

Pruess, Karsten

2005-01-01T23:59:59.000Z

355

Mechanical Compression Heat Pumps  

E-Print Network [OSTI]

MECHANICAL COMPRESSION HEAT PUMPS Thomas-L. Apaloo and K. Kawamura Mycom Corporation, Los Angeles, California J. Matsuda, Mayekawa Mfg. Co., Tokyo, Japan ABSTRACT Mechanical compression heat pumping is not new in industrial applications.... In fact, industry history suggests that the theoretical concept was developed before 1825. Heat pump manufacturers gained the support of consultants and end-users when the energy crisis hit this country in 1973. That interest, today, has been...

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

356

Sorption heat engines  

E-Print Network [OSTI]

For a simple free energy generating device - driven by thermal cycling and based on alternating adsorption and desorption - that has not been explicitly recognized as heat engine the name sorption heat engine is proposed. The mechanism is generally applicable to the fields of physics, chemistry, geology, and possibly, if relevant to the origin of life, biology. Four kinds of sorption heat engines are distinguished depending on the occurrence of changes in composition of the adsorbent or adsorbate during the thermal cycle.

Muller, A W J; Muller, Anthonie W. J.; Schulze-Makuch, Dirk

2005-01-01T23:59:59.000Z

357

Sputtering and heating of Titan's upper atmosphere  

Science Journals Connector (OSTI)

...Although, the plasma energy deposition...viable, but the plasma heating is inadequate...be true: another non-thermal process must be active...composition of the ambient plasma near Titan's orbit...used to test the atmospheric loss rate. Prior...

2009-01-01T23:59:59.000Z

358

Process for heating coal-oil slurries  

DOE Patents [OSTI]

Controlling gas to slurry volume ratio to achieve a gas holdup of about 0.4 when heating a flowing coal-oil slurry and a hydrogen containing gas stream allows operation with virtually any coal to solvent ratio and permits operation with efficient heat transfer and satisfactory pressure drops. The critical minimum gas flow rate for any given coal-oil slurry will depend on numerous factors such as coal concentration, coal particle size distribution, composition of the solvent (including recycle slurries), and type of coal. Further system efficiency can be achieved by operating with multiple heating zones to provide a high heat flux when the apparent viscosity of the gas saturated slurry is highest. Operation with gas flow rates below the critical minimum results in system instability indicated by temperature excursions in the fluid and at the tube wall, by a rapid increase and then decrease in overall pressure drop with decreasing gas flow rate, and by increased temperature differences between the temperature of the bulk fluid and the tube wall. At the temperatures and pressures used in coal liquefaction preheaters the coal-oil slurry and hydrogen containing gas stream behaves essentially as a Newtonian fluid at shear rates in excess of 150 sec[sup [minus]1]. The gas to slurry volume ratio should also be controlled to assure that the flow regime does not shift from homogeneous flow to non-homogeneous flow. Stable operations have been observed with a maximum gas holdup as high as 0.72. 29 figs.

Braunlin, W.A.; Gorski, A.; Jaehnig, L.J.; Moskal, C.J.; Naylor, J.D.; Parimi, K.; Ward, J.V.

1984-01-03T23:59:59.000Z

359

Process for heating coal-oil slurries  

DOE Patents [OSTI]

Controlling gas to slurry volume ratio to achieve a gas holdup of about 0.4 when heating a flowing coal-oil slurry and a hydrogen containing gas stream allows operation with virtually any coal to solvent ratio and permits operation with efficient heat transfer and satisfactory pressure drops. The critical minimum gas flow rate for any given coal-oil slurry will depend on numerous factors such as coal concentration, coal particle size distribution, composition of the solvent (including recycle slurries), and type of coal. Further system efficiency can be achieved by operating with multiple heating zones to provide a high heat flux when the apparent viscosity of the gas saturated slurry is highest. Operation with gas flow rates below the critical minimum results in system instability indicated by temperature excursions in the fluid and at the tube wall, by a rapid increase and then decrease in overall pressure drop with decreasing gas flow rate, and by increased temperature differences between the temperature of the bulk fluid and the tube wall. At the temperatures and pressures used in coal liquefaction preheaters the coal-oil slurry and hydrogen containing gas stream behaves essentially as a Newtonian fluid at shear rates in excess of 150 sec.sup. -1. The gas to slurry volume ratio should also be controlled to assure that the flow regime does not shift from homogeneous flow to non-homogeneous flow. Stable operations have been observed with a maximum gas holdup as high as 0.72.

Braunlin, Walter A. (Spring, TX); Gorski, Alan (Lovington, NM); Jaehnig, Leo J. (New Orleans, LA); Moskal, Clifford J. (Oklahoma City, OK); Naylor, Joseph D. (Houston, TX); Parimi, Krishnia (Allison Park, PA); Ward, John V. (Arvada, CO)

1984-01-03T23:59:59.000Z

360

Efficiency of some heat engines at maximum?power conditions  

Science Journals Connector (OSTI)

In the present paper a simple model is presented for a heat engine where the power output is limited by the rate of heat supply (and/or heat release). The model leads to a variety of results. Some of them are established laws such as the Carnot law the Curzon–Ahlborn efficiency and the Castañs efficiency. Other results are new and are related to phenomena as different as geothermal energy conversion and the Penfield paradox of electric circuits.

Alexis De Vos

1985-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Combined Heat and Power  

Office of Environmental Management (EM)

energy costs and 31 emissions while also providing more resilient and reliable electric power and thermal energy 1 . CHP 32 systems combine the production of heat (for both...

362

Waste Heat Recovery  

Office of Environmental Management (EM)

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

363

Solar Heating in Uppsala.  

E-Print Network [OSTI]

?? The housing corporation Uppsalahem has installed asolar heating system in the neighbourhood Haubitsen,which was renovated in 2011. This report examineshow much energy the solar… (more)

Blomqvist, Emelie; Häger, Klara

2012-01-01T23:59:59.000Z

364

HEATS: Thermal Energy Storage  

SciTech Connect (OSTI)

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

None

2012-01-01T23:59:59.000Z

365

Solar heating in Colombia.  

E-Print Network [OSTI]

?? This report describes the process of a thesis implemented in Colombia concerning solar energy. The project was to install a self-circulating solar heating system,… (more)

Skytt, Johanna

2012-01-01T23:59:59.000Z

366

Photovoltaic roof heat flux  

E-Print Network [OSTI]

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

Samady, Mezhgan Frishta

2011-01-01T23:59:59.000Z

367

Passive solar space heating  

SciTech Connect (OSTI)

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

Balcomb, J.D.

1980-01-01T23:59:59.000Z

368

Combined Heat & Power  

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

available today." -American Council for an Energy-Efficient Economy What is Combined Heat & Power (CHP)? Federal Utility Partnership Working Group May 7 - 8, 2014 Virginia...

369

Heat rejection system  

DOE Patents [OSTI]

A cooling system for rejecting waste heat consists of a cooling tower incorporating a plurality of coolant tubes provided with cooling fins and each having a plurality of cooling channels therein, means for directing a heat exchange fluid from the power plant through less than the total number of cooling channels to cool the heat exchange fluid under normal ambient temperature conditions, means for directing water through the remaining cooling channels whenever the ambient temperature rises above the temperature at which dry cooling of the heat exchange fluid is sufficient and means for cooling the water.

Smith, Gregory C. (Richland, WA); Tokarz, Richard D. (Richland, WA); Parry, Jr., Harvey L. (Richland, WA); Braun, Daniel J. (Richland, WA)

1980-01-01T23:59:59.000Z

370

Heat transfer dynamics  

SciTech Connect (OSTI)

As heat transfer technology increases in complexity, it becomes more difficult for those without thermal dynamics engineering training to choose between competitive heat transfer systems offered to meet their drying requirements. A step back to the basics of heat transfer can help professional managers and papermakers make informed decisions on alternative equipment and methods. The primary forms of heat and mass transfer are reviewed with emphasis on the basics, so a practical understanding of each is gained. Finally, the principles and benefits of generating infrared energy by combusting a gaseous hydrocarbon fuel are explained.

Smith, T.M. (Marsden, Inc., Pennsauken, NJ (United States))

1994-08-01T23:59:59.000Z

371

ARM - Atmospheric Heat Budget  

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

ListAtmospheric Heat Budget Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About...

372

Heat Transfer Enhancement for Finned-tube Heat Exchangers with Winglets  

SciTech Connect (OSTI)

This paper presents the results of an experimental study of forced convection heat transfer in a narrow rectangular duct fitted with a circular tube and/or a delta-winglet pair. The duct was designed to simulate a single passage in a fin-tube heat exchanger. Heat transfer measurements were obtained using a transient technique in which a heated airflow is suddenly introduced to the test section. High-resolution local fin-surface temperature distributions were obtained at several times after initiation of the transient using an imaging infrared camera. Corresponding local fin-surface heat transfer coefficient distributions were then calculated from a locally applied one-dimensional semi-infinite inverse heat conduction model. Heat transfer results were obtained over an airflow rate ranging from 1.51 x 10-3 to 14.0 x 10-3 kg/s. These flow rates correspond to a duct-height Reynolds number range of 670 – 6300 with a duct height of 1.106 cm and a duct width-toheight ratio, W/H, of 11.25. The test cylinder was sized such that the diameter-to-duct height ratio, D/H is 5. Results presented in this paper reveal visual and quantitative details of local fin-surface heat transfer distributions in the vicinity of a circular tube, a delta-winglet pair, and a combination of a circular tube and a delta-winglet pair. Comparisons of local and average heat transfer distributions for the circular tube with and without winglets are provided. Overall mean finsurface Nusselt-number results indicate a significant level of heat transfer enhancement associated with the deployment of the winglets with the circular cylinder. At the lowest Reynolds numbers (which correspond to the laminar operating conditions of existing geothermal air-cooled condensers), the enhancement level is nearly a factor of two. At higher Reynolds numbers, the enhancement level is close to 50%.

O'Brien, James Edward; Sohal, Manohar Singh

2000-11-01T23:59:59.000Z

373

The Spatial and Temporal Dependence of Coronal Heating by Alfven Wave Turbulence  

E-Print Network [OSTI]

The solar atmosphere may be heated by Alfven waves that propagate up from the convection zone and dissipate their energy in the chromosphere and corona. To further test this theory, we consider wave heating in an active region observed on 2012 March 7. A potential field model of the region is constructed, and 22 field lines representing observed coronal loops are traced through the model. Using a three-dimensional (3D) reduced magneto-hydrodynamics (MHD) code, we simulate the dynamics of Alfven waves in and near the observed loops. The results for different loops are combined into a single formula describing the average heating rate Q as function of position within the observed active region. We suggest this expression may be approximately valid also for other active regions, and therefore may be used to construct 3D, time-dependent models of the coronal plasma. Such models are needed to understand the role of thermal non-equilibrium in the structuring and dynamics of the Sun's corona.

Asgari-Targhi, M; Cranmer, S R; DeLuca, E E

2013-01-01T23:59:59.000Z

374

Union Power Cooperative - Residential Energy Efficient Heat Pump Loan  

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

Union Power Cooperative - Residential Energy Efficient Heat Pump Union Power Cooperative - Residential Energy Efficient Heat Pump Loan Program Union Power Cooperative - Residential Energy Efficient Heat Pump Loan Program < Back Eligibility Residential Savings Category Heating & Cooling Commercial Heating & Cooling Heat Pumps Maximum Rebate $7,500 Program Info State North Carolina Program Type Utility Loan Program Rebate Amount up to $7,500 Provider Union Power Cooperative Union Power Cooperative offers low interest loans to help its residential customers finance new, energy-efficient heat pumps. Interest rates, currently at 9%, will be fixed for the term of the loan. Loans can be up to $7,500 over five years. Customers pay back the loan with payments on monthly electric bills. There is a one time loan filing fee of $42. Contact

375

Dixie Electric Cooperative - Residential Heat Pump Loan Program |  

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

Dixie Electric Cooperative - Residential Heat Pump Loan Program Dixie Electric Cooperative - Residential Heat Pump Loan Program Dixie Electric Cooperative - Residential Heat Pump Loan Program < Back Eligibility Residential Savings Category Heating & Cooling Commercial Heating & Cooling Heat Pumps Home Weatherization Windows, Doors, & Skylights Maximum Rebate $5,000 Program Info State Alabama Program Type Utility Loan Program Rebate Amount up to $5,000 Provider Dixie Electric Cooperative Dixie Electric Cooperative, a Touchstone Electric Cooperative, offers the Energy Resources Conservation (ERC) loan to residential customers pursue energy efficiency measures. The program allows a maximum loan of $5,000 at a 5% interest rate. Funds can be used for improvements, upgrades, gas to electric conversions, or installation of a heat pump system. The payments

376

Heat Pumps | Department of Energy  

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

Heat Pumps Heat Pumps Heat Pumps Geothermal heat pumps are expensive to install but pay for themselves over time in reduced heating and cooling costs. Learn more about how geothermal heat pumps heat and cool buildings by concentrating the naturally existing heat contained within the earth -- a clean, reliable, and renewable source of energy. In moderate climates, heat pumps can be an energy-efficient alternative to furnaces and air conditioners. Several types of heat pumps are available, including air-source; geothermal; ductless, mini-split; and absorption heat pumps. Learn more about the different options and how to use your heat pump efficiently to save money and energy at home. Featured Heat Pump Systems A heat pump can provide an alternative to using your air conditioner. | Photo courtesy of iStockPhoto/LordRunar.

377

Union Light, Heat & Power Co | Open Energy Information  

Open Energy Info (EERE)

Union Light, Heat & Power Co Union Light, Heat & Power Co Jump to: navigation, search Name Union Light, Heat & Power Co Place Kentucky Utility Id 19446 References Energy Information Administration.[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Utility Rate Schedules Grid-background.png No rate schedules available. Average Rates No Rates Available The following table contains monthly sales and revenue data for Union Light, Heat & Power Co (Kentucky). Month RES REV (THOUSAND $) RES SALES (MWH) RES CONS COM REV (THOUSAND $) COM SALES (MWH) COM CONS IND_REV (THOUSAND $) IND SALES (MWH) IND CONS OTH REV (THOUSAND $) OTH SALES (MWH) OTH CONS TOT REV (THOUSAND $) TOT SALES (MWH) TOT CONS

378

Haywood EMC- Residential Heat Pump and Weatherization Loan Program  

Broader source: Energy.gov [DOE]

Haywood EMC offers a low interest loan to their residential customers to finance the purchase of an energy efficient heat pump and certain weatherization measures. The current interest rate is 5%...

379

Waste Heat Recovery from Industrial Process Heating Equipment -  

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

Waste Heat Recovery from Industrial Process Heating Equipment - Waste Heat Recovery from Industrial Process Heating Equipment - Cross-cutting Research and Development Priorities Speaker(s): Sachin Nimbalkar Date: January 17, 2013 - 11:00am Location: 90-2063 Seminar Host/Point of Contact: Aimee McKane Waste heat is generated from several industrial systems used in manufacturing. The waste heat sources are distributed throughout a plant. The largest source for most industries is exhaust / flue gases or heated air from heating systems. This includes the high temperature gases from burners in process heating, lower temperature gases from heat treat, dryers, and heaters, heat from heat exchangers, cooling liquids and gases etc. The previous studies and direct contact with the industry as well as equipment suppliers have shown that a large amount of waste heat is not

380

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ........................... 1,870 1,276 322 138 133 43.0 29.4 7.4 3.2 3.1 Building Floorspace (Square Feet) 1,001 to 5,000 ........................... 243 151 34 40 18 78.7 48.9 11.1 13.0 5.7 5,001 to 10,000 .......................... 202 139 31 29 Q 54.8 37.6 8.5 7.9 Q 10,001 to 25,000 ........................ 300 240 31 21 7 42.5 34.1 4.4 3.0 1.1 25,001 to 50,000 ........................ 250 182 40 11 Q 41.5 30.2 6.6 1.9 Q 50,001 to 100,000 ...................... 236 169 41 8 19 35.4 25.2 6.2 1.2 2.8 100,001 to 200,000 .................... 241 165 54 7 16 36.3 24.8 8.1 1.0 2.4 200,001 to 500,000 .................... 199 130 42 11 16 35.0 22.8 7.5 1.9 2.8 Over 500,000 ............................. 198

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings ............................. 2,037 1,378 338 159 163 42.0 28.4 7.0 3.3 3.4 Building Floorspace (Square Feet) 1,001 to 5,000 ........................... 249 156 35 41 18 78.6 49.1 11.0 12.9 5.6 5,001 to 10,000 .......................... 218 147 32 31 7 54.8 37.1 8.1 7.9 1.7 10,001 to 25,000 ........................ 343 265 34 25 18 43.8 33.9 4.4 3.2 2.3 25,001 to 50,000 ........................ 270 196 41 13 Q 40.9 29.7 6.3 2.0 2.9 50,001 to 100,000 ...................... 269 186 45 13 24 35.8 24.8 6.0 1.8 3.2 100,001 to 200,000 .................... 267 182 56 10 19 35.4 24.1 7.4 1.3 2.6 200,001 to 500,000 .................... 204 134 43 11 17 34.7 22.7 7.3 1.8 2.9 Over 500,000 .............................

382

Steady response to heating: Gaussian heat source  

E-Print Network [OSTI]

+ prescribed latent heating => "Matsuno-Gill model" Moisture equation for precipitation term ¡ Can make. of Equatorial Waves Filter out "background spectrum": ¡ Can see all different wave types! Especially Kelvin #12;Equatorial Waves Alternative theory for wave speed: ¡ Higher vertical mode structure causes phase

Frierson, Dargan

383

Proceedings of Heat Transfer 2003: ASME Summer Heat Transfer Conference  

E-Print Network [OSTI]

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

Kandlikar, Satish

384

Enhancing the heat transfer in a heat treatment furnace through improving the combustion process in the radiation tubes  

Science Journals Connector (OSTI)

......predicted and measured data. The CFD simulations...methods to improve the heat transfer rate and provide quantitative data which can be used...important in the combustion and the heat transfer processes...models on hydrogen-hydrocarbon combustion modelling......

E. M. Elmabrouk; Y. Wu

2012-02-01T23:59:59.000Z

385

Chemical heat pump  

DOE Patents [OSTI]

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

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

1984-01-01T23:59:59.000Z

386

Chemical heat pump  

DOE Patents [OSTI]

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.

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

1984-01-01T23:59:59.000Z

387

Chemical heat pump  

DOE Patents [OSTI]

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

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

1984-01-01T23:59:59.000Z

388

Chemical heat pump  

DOE Patents [OSTI]

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.

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

1981-01-01T23:59:59.000Z

389

Microchannel heat sink assembly  

DOE Patents [OSTI]

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

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

1992-03-24T23:59:59.000Z

390

IEEE TRANSACTIONS ON AUTOMATIC CONTROL, VOL. 58, NO. 12, DECEMBER 2013 2995 An Optimal Approximate Dynamic Programming  

E-Print Network [OSTI]

IEEE TRANSACTIONS ON AUTOMATIC CONTROL, VOL. 58, NO. 12, DECEMBER 2013 2995 An Optimal Approximate rates and the stock market (the low-dimensional exogenous state). · Each week a state has to make

Powell, Warren B.

391

Heat transfer and film cooling with steam injection  

E-Print Network [OSTI]

for both coolants was determined for similar blowing rates and was used as a basis for comparisons. Heat transfer coefficients were calcula- ted from the experimental data using a transient analysis. DEDICATION To my wife and family. ACKNOWLEDGEMENTS... LIST OF TABLES PAGE TABLE 1 Variation in the Blowing Rate ------------ 55 TABLE 2 TABLE 3 Typical Air Film Cooling Effectiveness Data Typical Steam Film Cooling Effectiveness Data 62 62 1X LIST OF FIGURES PAGE Figure 1 Comparison of Heat...

Conklin, Gary Eugene

1982-01-01T23:59:59.000Z

392

Vibrational Superposition States Without Rotating Wave Approximation  

E-Print Network [OSTI]

We propose a scheme to generate superpositions of coherent states for the vibrational motion of a laser cooled trapped-ion. It is based on the interaction with a standing wave making use of the counter-rotating terms, i.e. not applying the rotating wave approximation. We also show that the same scheme can be exploited for quantum state measurement, i.e. with the same scheme non-classical states may be reconstructed

Mancini, S; Tombesi, P

2000-01-01T23:59:59.000Z

393

Limit theorems for stochastic approximation algorithms  

E-Print Network [OSTI]

We prove a central limit theorem applicable to one dimensional stochastic approximation algorithms that converge to a point where the error terms of the algorithm do not vanish. We show how this applies to a certain class of these algorithms that in particular covers a generalized P\\'olya urn model, which is also discussed. In addition, we show how to scale these algorithms in some cases where we cannot determine the limiting distribution but expect it to be non-normal.

Renlund, Henrik

2011-01-01T23:59:59.000Z

394

Covering based approximation – a new type approach  

Science Journals Connector (OSTI)

The rough set theory, proposed by Pawlak is termed as basic (traditional) rough set theory and it has been extended in many directions. Covering based rough set is one of the extensions of the basic rough set theory. A covering is a generalisation of notion of partitioned rough set (Pawalk rough set) introduced by W. Zakowski. In this article it is introduced a new type of covering-based rough set in which both lower and upper approximation operators are improved.

Debadutta Mohanty

2010-01-01T23:59:59.000Z

395

Automating Logic Rectification by Approximate SPFDs  

Science Journals Connector (OSTI)

In the digital VLSI cycle, a netlist is often modified to correct design errors, perform small specification changes or implement incremental rewiring-based optimization operations. Most existing automated logic rectification tools use a small set of ... Keywords: SAT-based algorithm, approximate SPFD, digital VLSI cycle, design errors, incremental rewiring-based optimization operations, automated logic rectification tools, predefined logic transformations, memory/time explosion problem

Yu-Shen Yang; S. Sinha; A. Veneris; R. K. Brayton

2007-01-01T23:59:59.000Z

396

E-Print Network 3.0 - acid combustion rate Sample Search Results  

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

air flows are established to provide local and overall... content, and the combustion gas heat loss rate. ... Source: Columbia University - Waste-to-Energy Research and Technology...

397

Comparison of Numerical and Analytical Solutions of Heat Equation in R1n  

E-Print Network [OSTI]

Example Analytical Calculation of Heat Equation in 1-D 4 4 2-D Matrix Methods for Numerical Approximations Bibliography 11 8 Appendices 11 8.1 Graphs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 8.2 Matlab Code

Marzuola, Jeremy

398

Comparison of Heating Methods for In-Situ Oil Shale Extraction  

E-Print Network [OSTI]

Oil shales are lamellar, non-porous, impermeable hydrocarbon bearing rocks that contain organic matter called kerogen which, when heated at pyrolysis temperature of approximately 600-800 ?, thermo-chemically decomposes to liberate hydrocarbons...

Hazra, Kaushik Gaurav

2014-04-29T23:59:59.000Z

399

Solar heating system  

DOE Patents [OSTI]

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

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

1982-01-01T23:59:59.000Z

400

VISCOSITY AND RELAXATION APPROXIMATIONS FOR HYPERBOLIC SYSTEMS OF CONSERVATION LAWS  

E-Print Network [OSTI]

VISCOSITY AND RELAXATION APPROXIMATIONS FOR HYPERBOLIC SYSTEMS deal with the approximation of conservation * *laws via viscosity or relaxation. The following topics are covered: The general structure of viscosity and relaxation approximations is discu

Tzavaras, Athanasios E.

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Nonlinear adaptive control using radial basis function approximants  

E-Print Network [OSTI]

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

Petersen, Jerry Lee

1993-01-01T23:59:59.000Z

402

Knapsack Problems with Sigmoid Utilities: Approximation Algorithms via Hybrid Optimization$  

E-Print Network [OSTI]

Knapsack Problems with Sigmoid Utilities: Approximation Algorithms via Hybrid Optimization$ Vaibhav with sigmoid utilities. We merge approximation algorithms from discrete optimization with algorithms from continuous optimization to develop approximation algorithms for these NP-hard problems with sigmoid utilities

Bullo, Francesco

403

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

E-Print Network [OSTI]

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

Jafar, Farial A

2011-01-01T23:59:59.000Z

404

E-Print Network 3.0 - activation decay heat Sample Search Results  

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

h 1 in the dark... . Filtration reduced decay rates by various amounts, averaging 20%. Heat-labile, high... the loss of active degradative materials incurred by ... Source:...

405

Radiant Heating | Department of Energy  

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

Radiant Heating Radiant Heating Radiant Heating June 24, 2012 - 5:52pm Addthis In-wall radiant heating in a house under construction near Denver. | Photo courtesy of Warren Gretz, NREL. In-wall radiant heating in a house under construction near Denver. | Photo courtesy of Warren Gretz, NREL. Radiant heating systems supply heat directly to the floor or to panels in the wall or ceiling of a house. The systems depend largely on radiant heat transfer -- the delivery of heat directly from the hot surface to the people and objects in the room via infrared radiation. Radiant heating is the effect you feel when you can feel the warmth of a hot stovetop element from across the room. When radiant heating is located in the floor, it is often called radiant floor heating or simply floor heating.

406

Radiant Heating | Department of Energy  

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

Radiant Heating Radiant Heating Radiant Heating June 24, 2012 - 5:52pm Addthis In-wall radiant heating in a house under construction near Denver. | Photo courtesy of Warren Gretz, NREL. In-wall radiant heating in a house under construction near Denver. | Photo courtesy of Warren Gretz, NREL. Radiant heating systems supply heat directly to the floor or to panels in the wall or ceiling of a house. The systems depend largely on radiant heat transfer -- the delivery of heat directly from the hot surface to the people and objects in the room via infrared radiation. Radiant heating is the effect you feel when you can feel the warmth of a hot stovetop element from across the room. When radiant heating is located in the floor, it is often called radiant floor heating or simply floor heating.

407

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

E-Print Network [OSTI]

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

Noël Martin; Michael Urban

2015-01-05T23:59:59.000Z

408

Influence of variable property effects on natural convection flows in asymmetrically-heated vertical channels  

SciTech Connect (OSTI)

The influence of variable property effects on the laminar air flow induced by natural convection in a vertical, asymmetrically-heated channel is investigated. A full-elliptic model that accounts for variations of viscosity and thermal conductivity with temperature and determines the density from the state equation, has been solved numerically for cases for which variable property effects are important, particularly for conditions for which flow reversals may appear. The corresponding numerical results are compared with those obtained from an alternative model in which all thermophysical properties are assumed to be constant and the Boussinesq approximation is used. It has been found that variable property effects have a strong influence, not reported in previous works, on the recirculation patterns, and may produce, for certain ranges of parameters that roughly coincide with those for which flow reversals exist, an increase in the mass flow rate induced in the channel.

Zamora, B. [Univ. de Murcia (Spain)] [Univ. de Murcia (Spain); Hernandez, J. [Ciudad Universitaria, Madrid (Spain)] [Ciudad Universitaria, Madrid (Spain)

1997-12-01T23:59:59.000Z

409

Cooling power of the dilution refrigerator with a perfect continuous counterflow heat exchanger  

Science Journals Connector (OSTI)

The model of the perfect continuous counterflow heat exchanger introduced by Frossati et al. to describe the performance of dilution refrigerators is solved rigorously with the proper boundary condition. Unlike the original solution by Frossati et al. the present solution gives the refrigerator cooling power which is in good agreement with experimental data over the entire temperature range. The analysis of the cooling power using the present result allows more detailed evaluation of the refrigerator performance than has been possible with the analysis of the base temperature. An approximate expression for the cooling power is discussed which simplifies the prediction of the cooling rate of a large thermal load such as a copper nuclear?demagnetization stage.

Y. Takano

1994-01-01T23:59:59.000Z

410

Energy Department Invests to Save on Heating, Cooling and Lighting |  

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

to Save on Heating, Cooling and Lighting to Save on Heating, Cooling and Lighting Energy Department Invests to Save on Heating, Cooling and Lighting August 14, 2013 - 1:39pm Addthis News Media Contact (202) 586-4940 WASHINGTON - As part of the Obama Administration's efforts to reduce energy bills for American families and businesses and reduce greenhouse gas emissions, the Energy Department today announced 12 projects to develop innovative heating, cooling and insulation technologies as well as open source energy efficiency software to help homes and commercial buildings save energy and money. These projects will receive an approximately $11 million Energy Department investment, matched by about $1 million in private sector funding. "Energy efficient technologies - from improved heating and cooling

411

A new conceptual cold-end design of boilers for coal-fired power plants with waste heat recovery  

Science Journals Connector (OSTI)

Abstract After conducting an in-depth analysis of the conventional boiler cold-end design for waste heat recovery, this work proposed a new conceptual boiler cold-end design integrated with the steam cycle in a 1000 MW CFPP, in which the preheating of air was divided into high-temperature air preheater (HTAP), main air preheater (MAP) and low-temperature air preheater (LTAP). The HTAP and an economizer were installed in separate flue ducts, and the low temperature economizer (LTE) was situated between the MAP and the LTAP in the main flue duct to heat the condensed water. In the proposed boiler cold-end design, the flue gas waste heat was not only used to heat condensed water, but also to further preheat the combustion air. The air temperature at the air-preheater outlet increases and part of the steam bleeds with high exergy can be saved, resulting in greater energy-savings and better economics. Results showed that, for a typical 1000 MW CFPP in China, using the proposed boiler cold-end design for waste heat recovery could produce 13.3 MWe additional net power output with a heat rate reduction of approximately 112.0 kJ/kW h and could yield a net benefit of up to $85.8 M per year, which is much greater than those of the conventional cases. Exergy destruction is also reduced from 49.9 MWth in the conventional boiler cold-end design to 39.6 MWth in the proposed design.

Yongping Yang; Cheng Xu; Gang Xu; Yu Han; Yaxiong Fang; Dongke Zhang

2015-01-01T23:59:59.000Z

412

Relating magnetic reconnection to coronal heating  

E-Print Network [OSTI]

It is clear that the solar corona is begin heated and that coronal magnetic fields undergo reconnection all the time. Here we attempt to show that these two facts are in fact related - i.e. coronal reconnection generates heat. This attempt must address the fact that topological change of field lines does not automatically generate heat. We present one case of flux emergence where we have measured the rate of coronal magnetic reconnection and the rate of energy dissipation in the corona. The ratio of these two, $P/\\dot{\\Phi}$, is a current comparable to the amount of current expected to flow along the boundary separating the emerged flux from the pre-existing flux overlying it. We can generalize this relation to the overall corona in quiet Sun or in active regions. Doing so yields estimates for the contribution to corona heating from magnetic reconnection. These estimated rates are comparable to the amount required to maintain the corona at its observed temperature.

Longcope, Dana W

2015-01-01T23:59:59.000Z

413

The Monte Carlo Independent Column Approximation’s Conditional Random Noise: Impact on Simulated Climate  

Science Journals Connector (OSTI)

The Monte Carlo Independent Column Approximation (McICA) method for computing domain-average radiative fluxes is unbiased with respect to the full ICA, but its flux estimates contain conditional random noise. Results for five experiments are used ...

P. Räisänen; H. W. Barker; J. N. S. Cole

2005-11-01T23:59:59.000Z

414

Tushino - 3 district heating project/Moscow  

SciTech Connect (OSTI)

The contract for supply and installation of Honeywell control equipment at the district heating plant in Moscow suburb of Tushino was signed between the Mayor of Moscow and Honeywell in December 1991. Total contract value is US$3 million. The aim is to demonstrate on a pilot project the potential energy savings and improved pleat safety which can be achieved by means of electronic control of latest design. The Honeywell contract basically covers modernization of instrumentation and control of the gas fired heating plant, comprising water preparation and 4 boilers, of 100 Gcal/h each, i.e., 400 Gcal/h total. The plant is feeding the hot water network which has 60 heat exchanger stations connected. The heat exchangers (thermal rating between 2 to 10 Gcal/h each) supply hot water mainly to residential building blocks for apartment heating and domestic hot water. Honeywell`s responsibility covers engineering, supply of TDC 3000 micro-processor based control system for the boilers and DeltaNet Excel control for the Heat Exchangers. The contract also includes installation and start-up of the total control system.

Mayer, H.W.

1995-09-01T23:59:59.000Z

415

UF{sub 6} pressure excursions during cylinder heating  

SciTech Connect (OSTI)

As liquid UF{sub 6} inside a cylinder changes from a liquid to a solid, it forms a porous solid which occupies approximately the same volume as that of the liquid before cooling. Simultaneously as the liquid cools, UF{sub 6} vapor in the cylinder ullage above the liquid desublimes on the upper region of the inner cylinder wall. This solid is a dense, glass-like material which can accumulate to a significant thickness. The thickness of the solid coating on the upper cylinder wall and directly behind the cylinder valve area will vary depending on the conditions during the cooling stage. The amount of time lapsed between UF{sub 6} solidification and UF{sub 6} liquefaction can also affect the UF{sub 6} coating. This is due to the daily ambient heat cycle causing the coating to sublime from the cylinder wall to cooler areas, thus decreasing the thickness. Structural weakening of the dense UF{sub 6} layer also occurs due to cylinder transport vibration and thermal expansion. During cylinder heating, the UF{sub 6} nearest the cylinder wall will liquefy first. As the solid coating behind the cylinder valve begins to liquefy, it results in increased pressure depending upon the available volume for expansion. At the Paducah Gaseous Diffusion Plant (PGDP) during the liquefaction of the UF{sub 6} in cylinders in the UF{sub 6} feed and sampling autoclaves, this pressure increase has resulted in the activation of the systems rupture discs which are rated at 100 pounds per square inch differential.

Brown, P.G. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

1991-12-31T23:59:59.000Z

416

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

E-Print Network [OSTI]

-807. (5) K. Kesavan. The Use of Dissociating Gases As the Working Fluid in Thermodynamic Power Conversion Cycles, Ph.D. thesis. Carnegie-Mellon University, 1978, Ann Arbor, MI: University Microfilms International, 1978. 5. Heat amplifier with a gas...ABSTRACT Chemical heat pumps utilize working fluids which undergo reversible chemical changes. Mechanically driven reactive heat pump cycles or, alternatively, hl~a: driven heat pumps in which either heat engine or heat pump working fluid...

Kirol, L. D.

417

Chemical heat pump cools as well as heats  

Science Journals Connector (OSTI)

Chemical heat pump cools as well as heats ... Innovative heat pump uses methanol refrigerant, calcium chloride absorber to use and store solar energy for heating, air conditioning, hot water ... Though the EIC heat pump is similar in concept to other chemical heat pumps now being used or developed, it does offer a number of innovations, not the least of which are its novel refrigerant (methanol) and absorption medium (calcium chloride). ...

RON DAGANI

1980-10-20T23:59:59.000Z

418

Integrating preconcentrator heat controller  

DOE Patents [OSTI]

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

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

2007-10-16T23:59:59.000Z

419

Recovering the Heat Dissipated by the Digital Switching Equipment  

E-Print Network [OSTI]

to the atrrosphere by the cool ing plant servicing the digital switcher, to heat other parts of the building. Energy prices have not, in the past, diffe red considerably from the average inflation rate of the economy as a whole. This situation crea ted little... to water heat exchanger, using either double bundle condenser or other types of systems readily available. The system includes heat recovery chiller using integral double bund les or external heat exchangers, either moun ted in series or in parallel...

Karasseferian, V. V.; Desjardins, R.

1983-01-01T23:59:59.000Z

420

Longitudinal variation of tides in the MLT region: 2. Relative effects of solar radiative and latent heating  

E-Print Network [OSTI]

of solar radiative and latent heating Xiaoli Zhang,1 Jeffrey M. Forbes,1 and Maura E. Hagan2 Received 11 study examines the relative importance of radiative heating and latent heating in accounting (GSWM) and new tidal heating rates derived from International Satellite Cloud Climatology Project (ISCCP

Forbes, Jeffrey

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

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

Open Energy Info (EERE)

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

422

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

Office of Environmental Management (EM)

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

423

Heat treatment furnace  

DOE Patents [OSTI]

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

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

2014-10-21T23:59:59.000Z

424

Molecular heat pump  

E-Print Network [OSTI]

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

Dvira Segal; Abraham Nitzan

2005-10-11T23:59:59.000Z

425

Nonlinearity and memory effects in low temperature heat propagation  

E-Print Network [OSTI]

and bismuth at temperatures below where the materials reached their peak thermal conductivity (approximately of nonlinearity and memory on the propagation of heat waves through crystalline materials at low tempera- tures transverse and longitudinal mechanical waves). This material-dependent temperature of peak thermal

Saxton, Katarzyna

426

Heat pumps and under floor heating as a heating system for Finnish low-rise residential buildings.  

E-Print Network [OSTI]

??In bachelor’s thesis the study of under floor heating system with ground source heat pump for the heat transfers fluid heating is considered. The case… (more)

Chuduk, Svetlana

2010-01-01T23:59:59.000Z

427

Development of dual temperature ammines for heat pump latent heat storage application. Final report  

SciTech Connect (OSTI)

Ammoniated Complex Compounds can be used as working fluids in space heating and cooling heat pumps and storage systems. This report describes the theoretical and experimental development of complex compound working fluids for a heat pump-storage system. A computerized data base was developed for the preliminary selection of candidate working fluids. The selected substances were experimentally investigated. Several concepts using two ammoniated complex compounds or one complex compound and the plain ligand were developed. A subscale prototype was built using the NaBr-n NH/sub 3/ complex and NH/sub 3/ as the ligand. Two heat exchanger designs were tested and compared in terms of optimum reaction rates. A computer simulation was written to predict the performance of a complex compound heat pump-storage system. The results were compared with a simulation of a conventional R22 heat pump cycle. The influence of additives in the NaBr-n NH/sub 3/ complex was investigated with respect to the adsorption and desprption rates.

Rockenfeller, U.

1986-03-01T23:59:59.000Z

428

Generalized Polya urns via stochastic approximation  

E-Print Network [OSTI]

We collect, survey and develop methods of (one-dimensional) stochastic approximation in a framework that seems suitable to handle fairly broad generalizations of Polya urns. To show the applicability of the results we determine the limiting fraction of balls in an urn with balls of two colors. We consider two models generalizing the Polya urn, in the first one ball is drawn and replaced with balls of (possibly) both colors according to which color was drawn. In the second, two balls are drawn simultaneously and replaced along with balls of (possibly) both colors according to what combination of colors were drawn.

Renlund, Henrik

2010-01-01T23:59:59.000Z

429

2659 heat insulation [n] (2)  

Science Journals Connector (OSTI)

constr....(Protection against heat provided by heat-shielding materials in the outer walls of a building to prevent heat build-up in hot regions or in temperate climates during the summer. In tempera...

2010-01-01T23:59:59.000Z

430

Heat Transfer and Convection Currents  

Science Journals Connector (OSTI)

...October 1965 research-article Heat Transfer and Convection Currents D. C...convection in a medium with internal heat generation is discussed semi-quantitatively...States English United Kingdom 1966 Heat transfer and convection currents Tozer D...

1965-01-01T23:59:59.000Z

431

Heat and Sound Insulation Materials  

Science Journals Connector (OSTI)

Of the three heat transfer processes: heat conduction, convection and radiation, convectional heat transfer is reduced by fiber and foam insulation materials1, 2). Air circulation is prevented by compartmentalizi...

Dr. Andre Knop; Dr. Louis A. Pilato

1985-01-01T23:59:59.000Z

432

Residential heating oil prices decline  

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

heating oil prices decline The average retail price for home heating oil is 3.48 per gallon. That's down 4.5 cents from a week ago, based on the residential heating fuel survey by...

433

ANALYTIC APPROXIMATION OF CARBON CONDENSATION ISSUES IN TYPE II SUPERNOVAE  

SciTech Connect (OSTI)

I present analytic approximations for some issues related to condensation of graphite, TiC, and silicon carbide in oxygen-rich cores of supernovae of Type II. Increased understanding, which mathematical analysis can support, renders researchers more receptive to condensation in O-rich supernova gases. Taking SN 1987A as typical, my first analysis shows why the abundance of CO molecules reaches an early maximum in which free carbon remains more abundant than CO. This analysis clarifies why O-rich gas cannot oxidize C if {sup 56}Co radioactivity is as strong as in SN 1987A. My next analysis shows that the CO abundance could be regarded as being in chemical equilibrium if the CO molecule is given an effective binding energy rather than its laboratory dissociation energy. The effective binding energy makes the thermal dissociation rate of CO equal to its radioactive dissociation rate. This preserves possible relevance for the concept of chemical equilibrium. My next analysis shows that the observed abundances of CO and SiO molecules in SN 1987A rule out frequent suggestions that equilibrium condensation of SUNOCONs has occurred following atomic mixing of the He-burning shell with more central zones in such a way as to reproduce roughly the observed spectrum of isotopes in SUNOCONs while preserving C/O > 1. He atoms admixed along with the excess carbon would destroy CO and SiO molecules, leaving their observed abundances unexplained. The final analysis argues that a chemical quasiequilibrium among grains (but not gas) may exist approximately during condensation, so that its computational use is partially justified as a guide to which mineral phases would be stable against reactions with gas. I illustrate this point with quasiequilibrium calculations by Ebel and Grossman that have shown that graphite is stable even when O/C >1 if prominent molecules are justifiably excluded from the calculation of chemical equilibrium.

Clayton, Donald D., E-mail: claydonald@gmail.com [Department of Physics and Astronomy, Clemson University, Clemson, SC (United States)

2013-01-01T23:59:59.000Z

434

Advances in induction heating  

SciTech Connect (OSTI)

Electric induction heating, in situ, can distill (underground) high-heat-value (HHV) gas, coal tar, bitumen, and shale oil. This technique permits potentially lower cost exploitation of the solid fossil fuels: coal, oil shale, tar sand, and heavy oil. The products, when brought to the surface in gaseous form and processed, yield chemical feedstocks, natural gas, and petroleum. Residual coke can be converted, in situ, to low-heat-value (LHV) gas by a conventional water-gas process. LHV can be burned at the surface to generate electricity at low cost. The major cost of the installation will have been paid for by the HHV gas and tar distilled from the coal. There are 2 mechanisms of heating by electric induction. One uses displacement currents induced from an electric field. The other uses eddy currents induced by a magnetic field.

Not Available

1980-06-16T23:59:59.000Z

435

Solar Heating Contractor Licensing  

Broader source: Energy.gov [DOE]

Michigan offers a solar heating contractor specialty license to individuals who have at least three years of experience installing solar equipment under the direction of a licensed solar contractor...

436

Heating and cooling system  

SciTech Connect (OSTI)

Heating and cooling of dwelling houses and other confined spaces is facilitated by a system in which thermal energy is transported between an air heating and cooling system in the dwelling and a water heat storage sink or source, preferably in the form of a swimming pool or swimming pool and spa combination. Special reversing valve circuitry and the use of solar collectors and liquid-to-liquid heat exchangers on the liquid side of the system , and special air valves and air modules on the air side of the system, enhance the system's efficiency and make it practical in the sense that systems employing the invention can utilize existing craft skills and building financing arrangements and building codes, and the like, without major modification.

Krumhansl, M.U.

1982-10-12T23:59:59.000Z

437

Solar heated swimming pool  

SciTech Connect (OSTI)

A swimming pool construction incorporating solar heating means to heat the pool water to a desired level. The pool includes a surrounding safety fence supported by a plurality of fence supports which are hollow and which include internal passageways. The pool water is passed through the pool support passageways whereupon it absorbs heat from the sidewalls of the fence supports, the surfaces of which have been heated by solar radiation. The fence supports can be made of plastic or other materials, but preferably are dark for improved absorptivity. The pool water can be passed serially through each of the fence supports and suitable thermostat control means can be provided to limit the water temperature increase.

Pettit, F.M.

1984-10-02T23:59:59.000Z

438

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, J. K. Anderson, G. Fiksel, B. Hudson, S. C. Prager, J. S. Sarff, and J. C. Wright...

439

Wood Heating Fuel Exemption  

Broader source: Energy.gov [DOE]

This statute exempts from the state sales tax all wood or "refuse-derived" fuel used for heating purposes. The law does not make any distinctions about whether the qualified fuels are used for...

440

Absorption Heat Pump Developments  

Science Journals Connector (OSTI)

The implementation of both new thermodynamic cycles and new suitable fluids makes it possible to considerably widen the capacity to recover and upgrade low level heat contained particularly in industrial therm...

G. Cohen; A. Rojey

1983-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Curling in the heat  

Science Journals Connector (OSTI)

... heat sensor, shown here, has been developed by Jim Gimzewski and colleagues at IBM Riis-chlikon specifically for studies of surface reactions . A spin-off of the scanning probe ...

David A. King

1994-04-21T23:59:59.000Z

442

Upper bounds of the rates of decay for solutions of the Boussinesq equations  

Science Journals Connector (OSTI)

In this paper, upper bounds of the L 2-decay rate for the Boussinesq equations are considered. Using the L 2...decay rate of solutions for the heat equation, and assuming that the ...

Ying Liu

2011-01-01T23:59:59.000Z

443

ABSORPTION-DELAY MODELS OF HEAT TRANSPORT R.E. SHOWALTER AND D.B. VISARRAGA  

E-Print Network [OSTI]

ABSORPTION-DELAY MODELS OF HEAT TRANSPORT R.E. SHOWALTER AND D.B. VISARRAGA Abstract. A temperature jump in the water traveling through a pipe is delayed by the absorption of heat into the pipe wall transfer, absorption, memory, kinetic models, approximation. 1 #12;2 R.E. SHOWALTER AND D.B. VISARRAGA 1

444

JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER Vol. 16, No. 3, JulySeptember 2002  

E-Print Network [OSTI]

JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER Vol. 16, No. 3, July­September 2002 Three against the sizes of time increment and grid cell and angular discrete order are examined. The false order in SN approximation n = number of angular discretization Q = radiative heat ux R = re ectance r

Guo, Zhixiong "James"

445

Approximation method for spin-½ Ising models  

Science Journals Connector (OSTI)

An approximation for calculating the thermodynamic properties of spin-½ Ising models is described. The method is based on the formulation of Kramers and Wannier for the square lattice, and involves expressing the free energy in terms of the limiting maximum eigenvalue of a matrix sequence which represents the contribution from a single spin of the lattice. The application of this formulation to various two- and three-dimensional lattices shows that many of these are characterized by an identically structured matrix sequence with exactly two nonvanishing elements in each row and column. To explore the potential of using this similarity and its simplicity for analyzing Ising models we consider the two-dimensional square lattice in an external field and approximate the doubly infinite lattice by a semi-infinite one consisting of n (?10) infinitely long rows. Calculations are carried out and compared with (1) Onsager's formula for the free energy, (2) the Onsanger-Yang formula for the spontaneous magnetization, and (3) values calculated from series. Except for the region around the critical point where the correlation length exceeds n lattice spacings, substantial agreement—to better than 12 places of decimals in some cases—is obtained. As an additional measure of the potential of this method, a value for the critical exponent ? is computed by the extrapolation of the magnetization along the critical isotherm. The result is found to be in excellent agreement with the known value for ?.

Solomon Gartenhaus

1983-02-01T23:59:59.000Z

446

The effects of various approximations on electron-electron scattering calculations in QCLs  

E-Print Network [OSTI]

The effects of various approximations on electron-electron scattering calculations in QCLs Philip which are sometimes ignored in calculating electron-electron scattering rates. These effects include depends on the effects of electron transport. Electron-electron scattering is an essential mechanism

Massachusetts at Lowell, University of

447

Water Heating | Department of Energy  

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

to cut your water heating bill. Estimating Costs and Efficiency of Storage, Demand, and Heat Pump Water Heaters A water heater's energy efficiency is determined by the energy...

448

Heat flux limiting sleeves  

DOE Patents [OSTI]

A heat limiting tubular sleeve extending over only a portion of a tube having a generally uniform outside diameter, the sleeve being open on both ends, having one end thereof larger in diameter than the other end thereof and having a wall thickness which decreases in the same direction as the diameter of the sleeve decreases so that the heat transfer through the sleeve and tube is less adjacent the large diameter end of the sleeve than adjacent the other end thereof.

Harris, William G. (Tampa, FL)

1985-01-01T23:59:59.000Z

449

Heat Waves, Global Warming, and Mitigation  

E-Print Network [OSTI]

Heat Waves, Global Warming, and Mitigation Ann E. Carlson*II. HEAT WAVE DEFINITIONS .. A . HCHANGE AND HEAT WAVES .. CLIMATE III. IV. HEAT

Carlson, Ann E.

2008-01-01T23:59:59.000Z

450

CONDENSATION As noted previously, heat energy imparted to water as it  

E-Print Network [OSTI]

CONDENSATION As noted previously, heat energy imparted to water as it evaporates is returned to liquid water as vapor condenses. During low tide, the rate of evaporation typically exceeds the rate

Brody, James P.

451

An Improved Approximation Algorithm For Vertex Cover with Hard Capacities  

E-Print Network [OSTI]

An Improved Approximation Algorithm For Vertex Cover with Hard Capacities #3; Rajiv Gandhi y Eran-hard as it generalizes the well-known vertex cover problem. Previously, approximation algorithms with an approximation version of this problem is at least as hard as set cover; in addition, they developed a 3-approximation

Srinivasan, Aravind

452

On the mathematical treatment of the Born-Oppenheimer approximation.  

E-Print Network [OSTI]

On the mathematical treatment of the Born-Oppenheimer approximation. Thierry Jecko AGM, UMR 8088 du the main ideas used by mathematicians to show the accuracy of the Born-Oppenheimer approximation of the approximation in Chemistry. We contribute in this way to the discussion on the Born-Oppenheimer approximation

Paris-Sud XI, Université de

453

Stress Alters Rates and Types of Loss of Heterozygosity in Candida albicans  

Science Journals Connector (OSTI)

...noncommercial use, distribution, and reproduction...Types of Loss of Heterozygosity...stress, heat stress...1999. The distribution of rates...1985. Heat shock induces chromosome loss in the yeast...1949. The distribution of the numbers...types of loss of heterozygosity...stress, heat stress...

A. Forche; D. Abbey; T. Pisithkul; M. A. Weinzierl; T. Ringstrom; D. Bruck; K. Petersen; J. Berman

2011-08-01T23:59:59.000Z

454

rates | OpenEI  

Open Energy Info (EERE)

rates rates Dataset Summary Description This dataset, compiled by NREL and Ventyx, provides average residential, commercial and industrial electricity rates by zip code for both investor owned utilities (IOU) and non-investor owned utilities. Note: the file includes average rates for each utility, but not the detailed rate structure data found in the database available via the zip-code look-up feature on the OpenEI Utilities page (http://en.openei.org/wiki/Gateway:Utilities). The data was released by NREL/Ventyx in February 2011. Source NREL and Ventyx Date Released February 24th, 2012 (2 years ago) Date Updated Unknown Keywords electric rates rates US utilities Data text/csv icon IOU rates by zipcode (csv, 1.7 MiB) text/csv icon Non-IOU rates by zipcode (csv, 2.1 MiB)

455

Convective heat flow probe  

DOE Patents [OSTI]

A convective heat flow probe device is provided which measures heat flow and fluid flow magnitude in the formation surrounding a borehole. The probe comprises an elongate housing adapted to be lowered down into the borehole; a plurality of heaters extending along the probe for heating the formation surrounding the borehole; a plurality of temperature sensors arranged around the periphery of the probe for measuring the temperature of the surrounding formation after heating thereof by the heater elements. The temperature sensors and heater elements are mounted in a plurality of separate heater pads which are supported by the housing and which are adapted to be radially expanded into firm engagement with the walls of the borehole. The heat supplied by the heater elements and the temperatures measured by the temperature sensors are monitored and used in providing the desired measurements. The outer peripheral surfaces of the heater pads are configured as segments of a cylinder and form a full cylinder when taken together. A plurality of temperature sensors are located on each pad so as to extend along the length and across the width thereof, with a heating element being located in each pad beneath the temperature sensors. An expansion mechanism driven by a clamping motor provides expansion and retraction of the heater pads and expandable packet-type seals are provided along the probe above and below the heater pads.

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

1984-01-09T23:59:59.000Z

456

Intrinsically irreversible heat engine  

DOE Patents [OSTI]

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

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

1984-01-01T23:59:59.000Z

457

Sustainable heat extraction from abandoned mine tunnels: A numerical model  

Science Journals Connector (OSTI)

Abandoned mines are often associated with enduring liabilities which involve significant costs for decades after the decommissioning of the mine. Using a decommissioned mine as a geothermal resource can offset the environmental costs by supplying green heat to the communities living in and around the mine area. In this paper a numerical assessment of geothermal heat extraction from underground mine workings using an open loop geothermal system is carried out. In this study our focus is on fully flooded mines where the heat flow from the rock mass to the mine cavities is dominantly controlled by conduction in the rock mass. The sustainable heat flux into the mine workings is assessed using a transient two-dimensional axisymmetric heat transfer model. Finite volume method is applied to solve the model and simulate the transient temperature fields in the rock mass and within the water (flowing through cavities). The model is capable of controlling the rate of heat extraction through continuous adjustment of the rate of water flow through the mine. Sustainable rate of heat extraction is calculated for seasonally varied heat loads and for different project life cycles. It is shown that with proper resource management each kilometre of a typical deep underground mine tunnel can produce about 150?kW of usable heat in a sustainable manner. The model is validated by comparing its results with other published models and realistic data available from Springhill mine Nova Scotia Canada. It is found that the sustainable heat extraction is controlled dominantly by virgin rock temperature thermal conductivity of the rock mass and seasonal heat load variations.

S. A. Ghoreishi Madiseh; Mory M. Ghomshei; F. P. Hassani; F. Abbasy

2012-01-01T23:59:59.000Z

458

Solar collector for fluid heating system  

SciTech Connect (OSTI)

A solar collector for use in either an upfeed forced hot water heating system or a downfeed system features a pair of serpentine coils arranged in opposing flow relationship within a shallow insulated collector housing having a sealed glass closure panel. The two serpentine coils lie in spaced parallel planes within the housing, and the two coils are offset laterally so that their individual longitudinal loops overlap laterally by approximately one-half the width of each loop. The flow of heated fluid in each serpentine coil is controlled independently of the other coil by a temperature-responsive modulating valve connected in each coil close to the outlet end thereof within the housing. Efficiency of operation and practicality and economy of construction are featured.

Wilson, D.C.

1980-09-30T23:59:59.000Z

459

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 radiative transfer models - Spectrally resolved far-IR radiances, accurate PWV * Need to validate both clear sky (WV) absorption and cirrus scattering properties in these normally opaque bands Scientific Objectives * Conduct clear sky radiative closure studies in order to reduce uncertainties

460

Castor-1C spent fuel storage cask decay heat, heat transfer, and shielding analyses  

SciTech Connect (OSTI)

This report documents the decay heat, heat transfer, and shielding analyses of the Gesellschaft fuer Nuklear Services (GNS) CASTOR-1C cask used in a spent fuel storage demonstration performed at Preussen Elektra's Wurgassen nuclear power plant. The demonstration was performed between March 1982 and January 1984, and resulted in cask and fuel temperature data and cask exterior surface gamma-ray and neutron radiation dose rate measurements. The purpose of the analyses reported here was to evaluate decay heat, heat transfer, and shielding computer codes. The analyses consisted of (1) performing pre-look predictions (predictions performed before the analysts were provided the test data), (2) comparing ORIGEN2 (decay heat), COBRA-SFS and HYDRA (heat transfer), and QAD and DOT (shielding) results to data, and (3) performing post-test analyses if appropriate. Even though two heat transfer codes were used to predict CASTOR-1C cask test data, no attempt was made to compare the two codes. The codes are being evaluated with other test data (single-assembly data and other cask data), and to compare the codes based on one set of data may be premature and lead to erroneous conclusions.

Rector, D.R.; McCann, R.A.; Jenquin, U.P.; Heeb, C.M.; Creer, J.M.; Wheeler, C.L.

1986-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Reduce Your Heating Bills with Better Insulation | Department of Energy  

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

Reduce Your Heating Bills with Better Insulation Reduce Your Heating Bills with Better Insulation Reduce Your Heating Bills with Better Insulation October 3, 2008 - 11:09am Addthis John Lippert If you pay your own energy bills, you don't need to be reminded that energy prices are escalating. Energy price projections for this coming winter are not encouraging. According to the Energy Information Administration, residential natural gas prices during the upcoming heating season (October though March) are projected to average $14.93 per Mcf, an increase of about 17% compared to last year's heating season. Residential heating oil prices are projected to average $4.13 per gallon this winter, an increase of about 25%. What if you live in an all-electric house? Many utilities are continuing to pursue retail electricity rate increases in response to power generation

462

Reduce Your Heating Bills with Better Insulation | Department of Energy  

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

Reduce Your Heating Bills with Better Insulation Reduce Your Heating Bills with Better Insulation Reduce Your Heating Bills with Better Insulation October 3, 2008 - 11:09am Addthis John Lippert If you pay your own energy bills, you don't need to be reminded that energy prices are escalating. Energy price projections for this coming winter are not encouraging. According to the Energy Information Administration, residential natural gas prices during the upcoming heating season (October though March) are projected to average $14.93 per Mcf, an increase of about 17% compared to last year's heating season. Residential heating oil prices are projected to average $4.13 per gallon this winter, an increase of about 25%. What if you live in an all-electric house? Many utilities are continuing to pursue retail electricity rate increases in response to power generation

463

Heat Transfer from Augmented Flames and Plasma Jets Based on Magnetically Rotated Arcs  

Science Journals Connector (OSTI)

...November 1971 research-article Heat Transfer from Augmented Flames and Plasma...Jones F. J. Weinberg Rates of heat transfer to the inner surface of a surrounding...experimental data on a computer to yield heat transfer coefficients is developed on this...

1971-01-01T23:59:59.000Z

464

Heat–transfer effects of coalescence of bubbles from various site distributions  

Science Journals Connector (OSTI)

...October 2003 research-article Heat-transfer effects of coalescence of bubbles...FL 32611, USA A boiling-heat-transfer study with controlled coalescence...data-acquisition system, we found that the heat-transfer enhancement rate becomes higher...

2003-01-01T23:59:59.000Z

465

On the Effect of Porous Layers on Melting Heat Transfer in an Enclosure  

E-Print Network [OSTI]

On the Effect of Porous Layers on Melting Heat Transfer in an Enclosure E. A. Ellinger* and C. To enhance heat transfer, the porous layers are located in regions where the melting rates for a pure the porous layer and the pure fluid layer cause strong variations in heat transfer, melt convection

Beckermann, Christoph

466

Eric Moulton, Ferri Hassani, Pejman Nekoovaght Microwave-Assisted Heating in Rock  

E-Print Network [OSTI]

Eric Moulton, Ferri Hassani, Pejman Nekoovaght Microwave-Assisted Heating in Rock INTRODUCTION to expensive replacements. Expansive heating through microwaves breaks up the rock, which reduces the stress the mechanisms and parameters governing the heating rate of a material. Department of Mining and Materials

Barthelat, Francois

467

Heat generation from electronics increases with the advent of high-density integrated circuit technology. To  

E-Print Network [OSTI]

1 Abstract Heat generation from electronics increases with the advent of high-density integrated circuit technology. To come up with the heat generation, microscale cooling has been thought as a promising technology. Prediction of heat transfer rate is crucial in design of microscale cooling device

Boyer, Edmond

468

Simulation of Infrared Laser Heating of Silica Using Heat Conduction and Multifrequency Radiation Diffusion Equations Adapted for Homogeneous Refractive Lossy Media  

SciTech Connect (OSTI)

Localized, transient heating of materials using micro-scale, highly absorbing laser light has been used in many industries to anneal, melt and ablate material with high precision. Accurate modeling of the relative contributions of conductive, convective and radiative losses as a function of laser parameters is essential to optimizing micro-scale laser processing of materials. In bulk semi-transparent materials such as silicate glass melts, radiation transport is known to play a significantly larger role as the temperature increases. Conventionally, radiation is treated in the frequency-averaged diffusive limit (Rosseland approximation). However, the role and proper treatment of radiative processes under rapidly heated, high thermal gradient conditions, often created through laser-matter interactions, is at present not clear. Starting from the radiation transport equation for homogeneous, refractive lossy media, they derive the corresponding time-dependent multi-frequency diffusion equations. Zeroth and first moments of the transport equation couple the energy density, flux and pressure tensor. The system is closed by neglecting the temporal derivative of the flux and replacing the pressure tensor by its diagonal analogue. The radiation equations are coupled to a diffusion equation for the matter temperature. They are interested in modeling infrared laser heating of silica over sub-millimeter length scales, and at possibly rapid rates. Hence, in contrast to related work, they retain the temporal derivative of the radiation field. They derive boundary conditions at a planar air-silica interface taking account of reflectivities obtained from the Fresnel relations that include absorption. The effect of a temperature-dependent absorption index is explored through construction of a multi-phonon dielectric function that includes mode dispersion. The spectral dimension is discretized into a finite number of intervals yielding a system of multigroup diffusion equations. Simulations are presented. To demonstrate the bulk heat loss due to radiation and the effect of the radiation's temporal derivative, they model cooling of a silica slab, initially at 2500 K, for 10 s. Retaining the derivative enables correctly modeling the loss of photons initially present in the slab. Other simulations model irradiating silica discs (of approximately 5 mm radii and thickness) with a CO2 laser: {lambda} = 10.59 and 4.6 um, Gaussian profile, r{sub 0} = 0.5 mm for 1/e decay. By surrounding the disks in room-temperature air, they make use of the boundary conditions described above.

Shestakov, A I; Matthews, M J; Vignes, R M; Stolken, J S

2010-10-28T23:59:59.000Z

469

heat transfer | OpenEI Community  

Open Energy Info (EERE)

85 85 Varnish cache server Home Groups Community Central Green Button Applications Developer Utility Rate FRED: FRee Energy Database More Public Groups Private Groups Features Groups Blog posts Content Stream Documents Discussions Polls Q & A Events Notices My stuff Energy blogs 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation: XID: 2142229585 Varnish cache server heat transfer Home Dc's picture Submitted by Dc(15) Member 15 November, 2013 - 13:26 Living Walls ancient building system architect biomimicry building technology cooling cu daylight design problem energy use engineer fred andreas geothermal green building heat transfer heating living walls metabolic adjustment net zero pre-electricity Renewable Energy Solar university of colorado utility grid Wind

470

Radiative Heat Transfer between Neighboring Particles  

E-Print Network [OSTI]

The near-field interaction between two neighboring particles is known to produce enhanced radiative heat transfer. We advance in the understanding of this phenomenon by including the full electromagnetic particle response, heat exchange with the environment, and important radiative corrections both in the distance dependence of the fields and in the particle absorption coefficients. We find that crossed terms of electric and magnetic interactions dominate the transfer rate between gold and SiC particles, whereas radiative corrections reduce it by several orders of magnitude even at small separations. Radiation away from the dimer can be strongly suppressed or enhanced at low and high temperatures, respectively. These effects must be taken into account for an accurate description of radiative heat transfer in nanostructured environments.

Alejandro Manjavacas; F. Javier Garcia de Abajo

2012-01-26T23:59:59.000Z

471

Fuzzy predictive control of district heating network  

Science Journals Connector (OSTI)

This paper presents a concept for controlling the supply temperature in district heating networks (DHNs) using model predictive control. Due to the inherent non-linearity in the response characteristics caused by varying flow rates the use of fuzzy dynamic matrix control (DMC) is proposed. The fuzzy partitions of the local finite impulse response (FIR) models are constructed by an axis-orthogonal, incremental partitioning scheme. Furthermore, a novel approach for determining future fuzzy trajectory based on heat load forecasts is implemented. It is demonstrated that the fuzzy DMC performs well for the case study considered. In addition, different set point strategies are applied and the results are evaluated with respect to operational costs. In this context it is shown that the trade-off between pumping and heat loss cost plays an important role in minimising overall costs.

S. Grosswindhager; M. Kozek; Andreas Voigt; Lukas Haffner

2013-01-01T23:59:59.000Z

472

Local Heat Transfer for Finned-Tube Heat Exchangers using Oval Tubes  

SciTech Connect (OSTI)

This paper presents the results of an experimental study of forced convection heat transfer in a narrow rectangular duct fitted with either a circular tube or an elliptical tube in crossflow. The duct was designed to simulate a single passage in a fin-tube heat exchanger. Heat transfer measurements were obtained using a transient technique in which a heated airflow is suddenly introduced to the test section. High-resolution local fin-surface temperature distributions were obtained at several times after initiation of the transient using an imaging infrared camera. Corresponding local fin-surface heat transfer coefficient distributions were then calculated from a locally applied one-dimensional semi-infinite inverse heat conduction model. Heat transfer results were obtained over an airflow rate ranging from 1.56 x 10-3 to 15.6 x 10-3 kg/s. These flow rates correspond to a duct-height Reynolds number range of 630 – 6300 with a duct height of 1.106 cm and a duct width-toheight ratio, W/H, of 11.25. The test cylinder was sized such that the diameter-to-duct height ratio, D/H is 5. The elliptical tube had an aspect ratio of 3:1 and a/H equal to 4.33. Results presented in this paper reveal visual and quantitative details of local fin-surface heat transfer distributions in the vicinity of circular and oval tubes and their relationship to the complex horseshoe vortex system that forms in the flow stagnation region. Fin surface stagnation-region Nusselt numbers are shown to be proportional to the square-root of Reynolds number.

O'Brien, James Edward; Sohal, Manohar Singh

2000-08-01T23:59:59.000Z

473

Polynomial Approximations for Continuous Linear Programs  

E-Print Network [OSTI]

where the cost rate c(t), the right hand side vector b(t) as well as the matrices. G(t) and H(t, ...... the jth industry in order to produce a unit output of good j. Thus, in ...

2012-04-05T23:59:59.000Z

474

FEMP--Geothermal Heat Pumps  

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

heat pump-like an air conditioner or refrigera- heat pump-like an air conditioner or refrigera- tor-moves heat from one place to another. In the summer, a geothermal heat pump (GHP) operating in a cooling mode lowers indoor temperatures by transferring heat from inside a building to the ground outside or below it. Unlike an air condition- er, though, a heat pump's process can be reversed. In the winter, a GHP extracts heat from the ground and transfers it inside. Also, the GHP can use waste heat from summer air-conditioning to provide virtually free hot-water heating. The energy value of the heat moved is typically more than three times the electricity used in the transfer process. GHPs are efficient and require no backup heat because the earth stays at a relatively moderate temperature throughout the year.

475

Quasi-linear heating and acceleration in bi-Maxwellian plasmas  

SciTech Connect (OSTI)

Quasi-linear acceleration and heating rates are derived for drifting bi-Maxwellian distribution functions in a general nonrelativistic case for arbitrary wave vectors, propagation angles, and growth/damping rates. The heating rates in a proton-electron plasma due to ion-cyclotron/kinetic Alfvén and mirror waves for a wide range of wavelengths, directions of propagation, and growth or damping rates are explicitly computed.

Hellinger, Petr [Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague (Czech Republic)] [Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague (Czech Republic); Passot, Thierry; Sulem, Pierre-Louis [Université de Nice Sophia Antipolis, CNRS, Observatoire de la Côte d'Azur, BP 4229, 06304 Nice Cedex 4 (France)] [Université de Nice Sophia Antipolis, CNRS, Observatoire de la Côte d'Azur, BP 4229, 06304 Nice Cedex 4 (France); Trávní?ek, Pavel M. [Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague (Czech Republic) [Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague (Czech Republic); Space Sciences Laboratory, University of Berkeley, 7 Gauss Way, Berkeley, California 94720 (United States)

2013-12-15T23:59:59.000Z

476

Historical Interest Rates  

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

Current and Historical Interest Rates Current and Historical Interest Rates The table lists interest rates, from the project's inception through the present, for all projects with repayment supervised by the CRSP MC. The latest available interest rate is used for all future interest rate calculations. The Amistad-Falcon, Collbran, Provo River, and Rio Grande Projects are all assigned the average daily "Yield Rate" calculated by the U.S. Treasury, on an annual basis, for Treasury bonds having terms of 15 years or more remaining to maturity. The calculated yield rate is rounded to the nearest one-eighth of one percent. The yield rate is based upon the bond's interest rate, as well as its market value. The Colorado River Storage Project and its participating projects, Dolores and Seedskadee, are assigned the average daily "Coupon Rate," annualized for the same U.S. Treasury bonds used in "Yield Rate" calculations. The coupon rate is the interest rate that the bond carries upon its face.

477

Solar air heating system for combined DHW and space heating  

E-Print Network [OSTI]

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

478

PreHeat: Controlling Home Heating Using Occupancy Prediction  

E-Print Network [OSTI]

@comp.lancs.ac.uk ABSTRACT Home heating is a major factor in worldwide energy use. Our system, PreHeat, aims to more, and measuring actual gas consumption and occupancy. In UK homes PreHeat both saved gas and reduced MissTime (the Home heating uses more energy than any other residential energy expenditure including air conditioning

Krumm, John

479

PERPENDICULAR ION HEATING BY REDUCED MAGNETOHYDRODYNAMIC TURBULENCE  

SciTech Connect (OSTI)

Recent theoretical studies argue that the rate of stochastic ion heating in low-frequency Alfvén-wave turbulence is given by Q = c{sub 1}((?u){sup 3}/?)exp (– c{sub 2}/?), where ?u is the rms turbulent velocity at the scale of the ion gyroradius ?, ? = ?u/v{sub i}, v{sub i} is the perpendicular ion thermal speed, and c{sub 1} and c{sub 2} are dimensionless constants. We test this theoretical result by numerically simulating test particles interacting with strong reduced magnetohydrodynamic (RMHD) turbulence. The heating rates in our simulations are well fit by this formula. The best-fit values of c{sub 1} are ?1. The best-fit values of c{sub 2} decrease (i.e., stochastic heating becomes more effective) as the Reynolds number and the number of grid points in the RMHD simulations increase. As an example, in a 1024{sup 2} × 256 RMHD simulation with a dissipation wavenumber of the order of the inverse ion gyroradius, we find c{sub 2} = 0.21. We show that stochastic heating is significantly stronger in strong RMHD turbulence than in a field of randomly phased Alfvén waves with the same power spectrum, because coherent structures in strong RMHD turbulence increase orbit stochasticity in the regions where ions are heated most strongly. We find that c{sub 1} increases by a factor of ?3 while c{sub 2} changes very little as the ion thermal speed increases from values <heating in the solar wind.

Xia, Qian; Perez, Jean C.; Chandran, Benjamin D. G. [Space Science Center and Department of Physics, University of New Hampshire, Durham, NH (United States); Quataert, Eliot, E-mail: qdy2@unh.edu, E-mail: benjamin.chandran@unh.edu, E-mail: jeanc.perez@unh.edu, E-mail: eliot@astro.berkeley.edu [Astronomy Department and Theoretical Astrophysics Center, 601 Campbell Hall, The University of California, Berkeley, CA 94720 (United States)

2013-10-20T23:59:59.000Z

480

The Approximability Behaviour of Some Combinatorial Problems with Respectto the Approximability of a Class of Maximum Independent Set Problems  

Science Journals Connector (OSTI)

We prove that the existence of a polynomial time ?-approximation algorithm (where ? < 1 is a fixed constant) for a class of independent set problems, leads to a polynomial time approximation algorithm with approximation ratio strictly ... Keywords: NP-complete problem, convex programming, independent set, polynomial time approximation algorithm, quadratic programming, vertex covering

Marc Demange; Vangelis Th. Paschos

1997-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "approximate heat rates" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Influence of circumferential solar heat flux distribution on the heat transfer coefficients of linear Fresnel collector absorber tubes  

Science Journals Connector (OSTI)

Abstract The absorber tubes of solar thermal collectors have enormous influence on the performance of the solar collector systems. In this numerical study, the influence of circumferential uniform and non-uniform solar heat flux distributions on the internal and overall heat transfer coefficients of the absorber tubes of a linear Fresnel solar collector was investigated. A 3D steady-state numerical simulation was implemented based on ANSYS Fluent code version 14. The non-uniform solar heat flux distribution was modelled as a sinusoidal function of the concentrated solar heat flux incident on the circumference of the absorber tube. The k–? model was employed to simulate the turbulent flow of the heat transfer fluid through the absorber tube. The tube-wall heat conduction and the convective and irradiative heat losses to the surroundings were also considered in the model. The average internal and overall heat transfer coefficients were determined for the sinusoidal circumferential non-uniform heat flux distribution span of 160°, 180°, 200° and 240°, and the 360° span of circumferential uniform heat flux for 10 m long absorber tubes of different inner diameters and wall thicknesses with thermal conductivity of 16.27 W/mK between the Reynolds number range of 4000 and 210,000 based on the inlet temperature. The results showed that the average internal heat transfer coefficients for the 360° span of circumferential uniform heat flux with different concentration ratios on absorber tubes of the same inner diameters, wall thicknesses and thermal conductivity were approximately the same, but the average overall heat transfer coefficient increased with the increase in the concentration ratios of the uniform heat flux incident on the tubes. Also, the average internal heat transfer coefficient for the absorber tube with a 360° span of uniform heat flux was approximately the same as that of the absorber tubes with the sinusoidal circumferential non-uniform heat flux span of 160°, 180°, 200° and 240° for the heat flux of the same concentration ratio, but the average overall heat transfer coefficient for the uniform heat flux case was higher than that of the non-uniform flux distributions. The average axial local internal heat transfer coefficient for the 360° span of uniform heat flux distribution on a 10 m long absorber tube was slightly higher than that of the 160°, 200° and 240° span of non-uniform flux distributions at the Reynolds number of 4 000. The average internal and overall heat transfer coefficients for four absorber tubes of different inner diameters and wall thicknesses and thermal conductivity of 16.27 W/mK with 200° span of circumferential non-uniform flux were found to increase with the decrease in the inner-wall diameter of the absorber tubes. The numerical results showed good agreement with the Nusselt number experimental correlations for fully developed turbulent flow available in the literature.

Izuchukwu F. Okafor; Jaco Dirker; Josua P. Meyer

2014-01-01T23:59:59.000Z

482

Examining the Impact of Spatial Development Patterns on Regional Heat Island Effect in Metropolitan Regions of the United States  

E-Print Network [OSTI]

Effects of the Urban Structure on Heat Morality,? he argued that higher death rates in cities are due to climate modification (temperature, wind speed, radiant heat, and microclimatic effect) accompanied by urbanization. Based on case studies of historic...

Kim, Heeju

2013-07-08T23:59:59.000Z

483

Semiclassical approximation to supersymmetric quantum gravity  

SciTech Connect (OSTI)

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.

Kiefer, Claus; Lueck, Tobias; Moniz, Paulo [Institut fuer Theoretische Physik, Universitaet zu Koeln, Zuelpicher Strasse 77, 50937 Cologne (Germany); Astronomy Unit, School of Mathematical Sciences, Queen Mary College, University of London, Mile End Road, London E1 4NS (United Kingdom)

2005-08-15T23:59:59.000Z

484

Adiabatic Approximation, Semiclassical Scattering, and Unidirectional Invisibility  

E-Print Network [OSTI]

The transfer matrix of a possibly complex and energy-dependent scattering potential can be identified with the $S$-matrix of a two-level time-dependent non-Hermitian Hamiltonian H(t). We show that the application of the adiabatic approximation to H(t) corresponds to the semiclassical description of the original scattering problem. In particular, the geometric part of the phase of the evolving eigenvectors of H(t) gives the pre-exponential factor of the WKB wave functions. We use these observations to give an explicit semiclassical expression for the transfer matrix. This allows for a detailed study of the semiclassical unidirectional reflectionlessness and invisibility. We examine concrete realizations of the latter in the realm of optics.

Ali Mostafazadeh

2014-01-17T23:59:59.000Z

485

Cost Analysis Rate Settin  

E-Print Network [OSTI]

Cost Analysis and Rate Settin for Animal Research Facilities #12;#12;Cost Analysis and Rate ... .. . ...................... . . . ................................. . .... 7 Chapter 2 Preparation for Cost Analysis ......................................................... 9 Chapter 3 Assignment of Costs to Animal Research Facility Cost Centers

Baker, Chris I.

486

Subcooled Boiling Near a Heated Wall  

SciTech Connect (OSTI)

Experimental measurements of void fraction, bubble frequency, and velocity are obtained in subcooled R-134a flowing over a heated flat plate near an unheated wall and compared to analytical predictions. The measurements were obtained for a fixed system pressure and mass flow rate (P = 2.4 MPa and w = 106 kg/hr) at various inlet liquid temperatures. During the experiments, electrical power was applied at a constant rate to one side of the test section. The local void fraction data, acquired with a hot-film anemometer probe, showed the existence of a significant peak near the heated wall and a smaller secondary peak near the unheated wall for the larger inlet subcoolings. Local vapor velocity data, taken with the hot-film probe and a laser Doppler velocimeter, showed broad maxima near the centerline between the heated and unheated plates. Significant temperature gradients near the heated wall were observed for large inlet subcooling. Bubble size data, inferred from measurements of void fraction, bubble frequency and vapor velocity, when combined with the measured bubble chord length distributions illustrate the transition from pure three dimensional spherical to two-dimensional planar bubble flow, the latter being initiated when the bubbles fill the gap between the plates. These various two-phase flow measurements were used for development of a multidimensional, four-field calculational method; comparisons of the data to the calculations show reasonable agreement.

T.A. Trabold; C.C. Maneri; P.F. Vassallo; D.M. Considine

2000-10-27T23:59:59.000Z

487

Influence of roughness on near-field heat transfer between two plates  

E-Print Network [OSTI]

The surface roughness correction to the near-field heat transfer between two rough bulk materials is discussed by using second-order perturbation theory. The results allow for estimating the impact of surface roughness to the heat transfer in recent experiments between two plates and between a microsphere and a plate (using the Derjaguin approximation). Furthermore, we show that the proximity approximation for describing rough surfaces is valid for distances much smaller than the correlation length of the surface roughness even if the heat transfer is dominated by the coupling of surface modes.

Svend-Age Biehs; Jean-Jacques Greffet

2011-03-11T23:59:59.000Z

488

Stochastic quasi-steady state approximations for asymptotic solutions of the chemical master equation  

SciTech Connect (OSTI)

In this paper, we propose two methods to carry out the quasi-steady state approximation in stochastic models of enzyme catalytic regulation, based on WKB asymptotics of the chemical master equation or of the corresponding partial differential equation for the generating function. The first of the methods we propose involves the development of multiscale generalisation of a WKB approximation of the solution of the master equation, where the separation of time scales is made explicit which allows us to apply the quasi-steady state approximation in a straightforward manner. To the lowest order, the multi-scale WKB method provides a quasi-steady state, Gaussian approximation of the probability distribution. The second method is based on the Hamilton-Jacobi representation of the stochastic process where, as predicted by large deviation theory, the solution of the partial differential equation for the corresponding characteristic function is given in terms of an effective action functional. The optimal transition paths between two states are then given by those paths that maximise the effective action. Such paths are the solutions of the Hamilton equations for the Hamiltonian associated to the effective action functional. The quasi-steady state approximation is applied to the Hamilton equations thus providing an approximation to the optimal transition paths and the transition time between two states. Using this approximation we predict that, unlike the mean-field quasi-steady approximation result, the rate of enzyme catalysis depends explicitly on the initial number of enzyme molecules. The accuracy and validity of our approximated results as well as that of our predictions regarding the behaviour of the stochastic enzyme catalytic models are verified by direct simulation of the stochastic model using Gillespie stochastic simulation algorithm.

Alarcón, Tomás [Centre de Recerca Matemàtica, Edifici C, Campus de Bellaterra, 08193 Bellaterra (Barcelona) (Spain) [Centre de Recerca Matemàtica, Edifici C, Campus de Bellaterra, 08193 Bellaterra (Barcelona) (Spain); Departament de Matemàtiques, Universitat Atonòma de Barcelona, 08193 Bellaterra (Barcelona) (Spain)

2014-05-14T23:59:59.000Z

489

Heat exchanger-accumulator  

DOE Patents [OSTI]

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

Ecker, Amir L. (Dallas, TX)

1980-01-01T23:59:59.000Z

490

PROTON, ELECTRON, AND ION HEATING IN THE FAST SOLAR WIND FROM NONLINEAR COUPLING BETWEEN ALFVENIC AND FAST-MODE TURBULENCE  

SciTech Connect (OSTI)

In the parts of the solar corona and solar wind that experience the fewest Coulomb collisions, the component proton, electron, and heavy ion populations are not in thermal equilibrium with one another. Observed differences in temperatures, outflow speeds, and velocity distribution anisotropies are useful constraints on proposed explanations for how the plasma is heated and accelerated. This paper presents new predictions of the rates of collisionless heating for each particle species, in which the energy input is assumed to come from magnetohydrodynamic (MHD) turbulence. We first created an empirical description of the radial evolution of Alfven, fast-mode, and slow-mode MHD waves. This model provides the total wave power in each mode as a function of distance along an expanding flux tube in the high-speed solar wind. Next, we solved a set of cascade advection-diffusion equations that give the time-steady wavenumber spectra at each distance. An approximate term for nonlinear coupling between the Alfven and fast-mode fluctuations is included. For reasonable choices of the parameters, our model contains enough energy transfer from the fast mode to the Alfven mode to excite the high-frequency ion cyclotron resonance. This resonance is efficient at heating protons and other ions in the direction perpendicular to the background magnetic field, and our model predicts heating rates for these species that agree well with both spectroscopic and in situ measurements. Nonetheless, the high-frequency waves comprise only a small part of the total Alfvenic fluctuation spectrum, which remains highly two dimensional as is observed in interplanetary space.

Cranmer, Steven R.; Van Ballegooijen, Adriaan A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2012-08-01T23:59:59.000Z

491

Proton heating by parallel Alfven wave cascade  

SciTech Connect (OSTI)

In a recent series of papers, the present authors developed a kinetic theory for low-frequency turbulence propagating parallel to the ambient magnetic field. Making use of this theory, it was shown that low-frequency Alfvenic turbulence may cascade to ion-cyclotron frequency range and beyond by nonlinear three-wave decay processes. The significance of such a finding is that it may lead to the proton heating by cyclotron resonance. However, the actual proton heating process was not demonstrated. The present paper complements the previous works by including the proton heating in the discussion. It is found that the left-hand circularly polarized Alfven-cyclotron turbulence leads to a moderate heating of the protons in the perpendicular direction and cooling in the parallel direction. It is also found that ion-acoustic turbulence is generated by the decay instability process. Finally, the heating rate is shown to increase in inverse proportion to the time scale of the wave source.

Yoon, P. H.; Fang, T.-M. [Massachusetts Technological Laboratory, Inc., 330 Pleasant Street, Belmont, Massachusetts 02478 (United States)

2009-06-15T23:59:59.000Z

492

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

SciTech Connect (OSTI)

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

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

2013-01-01T23:59:59.000Z

493

Utility Rate Discount | Open Energy Information  

Open Energy Info (EERE)

Discount Discount Jump to: navigation, search A few electric utilities offer rate discounts to encourage residential energy efficiency. For homes that meet certain energy efficiency criteria, such as those established by the federal Energy Star program, the owner or tenant is awarded a percentage discount on each monthÂ’s electric bill. [1] Utility Rate Discount Incentives CSV (rows 1 - 14) Incentive Incentive Type Place Applicable Sector Eligible Technologies Active Cleco Power - Power Miser New Home Program (Louisiana) Utility Rate Discount Louisiana Residential Building Insulation Central Air conditioners Clothes Washers Comprehensive Measures/Whole Building Doors Duct/Air sealing Furnaces Heat pumps Water Heaters Windows Yes Dominion North Carolina Power - Energy Saver Home Plus (North Carolina) Utility Rate Discount North Carolina Residential Water Heaters

494

The Extended Fe Distribution in the Intracluster Medium and the Implications Regarding AGN Heating  

Science Journals Connector (OSTI)

We present a systematic analysis of XMM-Newton observations of eight cool-core clusters of galaxies and determine the Fe distribution in the intracluster medium relative to the stellar distribution in the central dominant galaxy (CDG). Our analysis shows that the Fe is significantly more extended than the stellar mass in the CDG in all of the clusters in our sample, with a slight trend of increasing extent with increasing central cooling time. The excess Fe within the central 100 kpc in these clusters can be produced by Type Ia supernovae from the CDG over the past 3-7 Gyr. Since the excess Fe primarily originates from the CDG, it is a useful probe for determining the motion of the gas and the mechanical energy deposited by AGN outbursts over the past ~5 Gyr in the centers of clusters. We explore two possible mechanisms for producing the greater extent of the Fe relative to the stars in the CDG, bulk expansion of the gas and turbulent diffusion of the Fe. Assuming that the gas and Fe expand together, we find that a total energy of 1060-1061 erg s?1 must have been deposited into the central 100 kpc of these clusters in order to produce the currently observed Fe distributions. Since the required enrichment time for the excess Fe is approximately 5 Gyr in these clusters, this gives an average AGN mechanical power over this time of 1043-1044 erg s?1. The extended Fe distribution in cluster cores can also arise from turbulent diffusion. Assuming a steady state (i.e., the outward mass flux of Fe across a given surface is equal to the mass injection rate of Fe within that surface), we find that diffusion coefficients of 1029-1030 cm2 s?1 are required in order to maintain the currently observed Fe profiles. We find that heating by both turbulent diffusion of entropy and dissipation are important heating mechanisms in cluster cores. In half of the clusters with central cooling times greater than 1 Gyr, we find that heating by turbulent diffusion of entropy alone can balance radiative losses. In the remaining clusters, some additional heating by turbulent dissipation, with turbulent velocities of 150-300 km s?1, is required in order to balance radiative cooling. We also find that the average Type Ia supernova fraction within the central 100 kpc of these clusters is 0.53 (roughly twice the solar value), on the basis of the Si-to-Fe mass ratio. This implies a total (Type Ia plus core-collapse) supernova heating rate of less than 10% of the bolometric X-ray luminosity within the centers of clusters.

Laurence P. David; Paul E. J. Nulsen

2008-01-01T23:59:59.000Z

495

Mixed convection flow and heat transfer in entrance region of rectangular ducts rotating about a parallel axis  

SciTech Connect (OSTI)

The objective of the present work is to investigate the laminar mixed convection flow and heat transfer in the entrance region of heated rectangular ducts rotating about a parallel axis. Heating conditions of isothermal and iso-flux are both considered. Boussinesq approximation is invoked to take into account buoyancy effect induced by centrifugal force. Navier-Stokes/Boussinesq system can be cast into a dimensionless form, in which five governing parameters, the Prandtl number Pr, rotational Reynolds number J, rotational Grashof number Gr{sub {Omega}}, aspect ratio {gamma} and the eccentricity E, are involved. Mechanisms of secondary vortex development in the ducts are explored by a theoretical analysis on vorticity transport equation. The values of Pr and E are fixed as 0.7 and 10, respectively. For various combinations of the other thee parameters, a vorticity-velocity method implemented with a marching technique is employed to solve the resultant three-dimensional system for simultaneously developing flow and temperature fields. The emphasis is placed on the rotational effects, including both coriolis force and centrifugal buoyancy; on the non-isothermal flow and the related