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Note: This page contains sample records for the topic "operating heat rate" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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1

Heat Rate Program Guidelines  

Science Conference Proceedings (OSTI)

Power plant facilities with performance or heat rate improvement programs perform better than those that do not have those programs. A heat rate improvement program typically provides sufficient information for decision making with respect to timely maintenance actions and/or operational adjustments. Monitoring the performance of any power plant component includes the trending of parameters that also describe the performance of other plant components, providing insight and information on improving ...

2012-12-31T23:59:59.000Z

2

2011 Heat Rate Improvement Conference  

Science Conference Proceedings (OSTI)

With the rising cost of fuel and the strong possibility of CO2 emissions regulations and limitations in the near future, utilities and power generation companies are focusing on power plant heat rate and performance. The Electric Power Research Institute (EPRI) 17th Heat Rate Improvement Conference is the latest in a series of meetings designed to assist attendees in addressing problems with power plant performance and in identifying cost-effective solutions for achieving and sustaining heat rate improve...

2011-03-28T23:59:59.000Z

3

Heat Transfer Operators Associated with Quantum Operations  

E-Print Network (OSTI)

Any quantum operation applied on a physical system is performed as a unitary transformation on a larger extended system. If the extension used is a heat bath in thermal equilibrium, the concomitant change in the state of the bath necessarily implies a heat exchange with it. The dependence of the average heat transferred to the bath on the initial state of the system can then be found from the expectation value of a hermitian operator, which is named as the heat transfer operator (HTO). The purpose of this article is the investigation of the relation between the HTOs and the associated quantum operations. Since, any given quantum operation on a system can be realized by different baths and unitaries, many different HTOs are possible for each quantum operation. On the other hand, there are also strong restrictions on the HTOs which arise from the unitarity of the transformations. The most important of these is the Landauer erasure principle. This article is concerned with the question of finding a complete set of restrictions on the HTOs that are associated with a given quantum operation. An answer to this question has been found only for a subset of quantum operations. For erasure operations, these characterizations are equivalent to the generalized Landauer erasure principle. For the case of generic quantum operations however, it appears that the HTOs obey further restrictions which cannot be obtained from the entropic restrictions of the generalized Landauer erasure principle.

Ç. Aksak; S. Turgut

2010-02-03T23:59:59.000Z

4

ARM - Measurement - Radiative heating rate  

NLE Websites -- All DOE Office Websites (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

5

Heat Rate Improvement Reference Manual  

Science Conference Proceedings (OSTI)

Performance optimization of fossil power plants is a high priority within the electric utilities in the new competitive environment. This manual can help utility engineers establish a heat rate improvement program.

1998-07-27T23:59:59.000Z

6

EPRI's Twelfth Heat Rate Improvement Conference Proceedings  

Science Conference Proceedings (OSTI)

The Twelfth Heat Rate Improvement Conference, sponsored by EPRI's Heat Rate and Cost Optimization Value Package, is the latest in a series of meetings designed to assist utilities in addressing problems with power plant performance and in identifying cost-effective solutions for achieving and maintaining heat rate improvement. The last conference was held in Baltimore in September 1998.

2001-01-22T23:59:59.000Z

7

2007 EPRI Heat Rate Improvement Conference Proceedings  

Science Conference Proceedings (OSTI)

Due to the rising cost of fuel and the growing possibility of carbon taxes in the not-too-distant future, utilities are once again focusing on the heat rate and performance of coal-fired power plants. The fifteenth Heat Rate Improvement Conference is the latest in this series of meetings designed to assist utilities in addressing problems with power plant performance and in identifying cost-effective solutions for achieving and maintaining heat rate improvement.

2007-03-30T23:59:59.000Z

8

Proceedings 2013 Heat Rate Improvement Conference  

Science Conference Proceedings (OSTI)

With the rising cost of fuel and the strong possibility of CO2 emissions regulations and limitations in the near future, utilities and power generation companies are focusing on power plant heat rate and performance. The 18th Heat Rate Improvement Conference is the latest in a series of meetings designed to assist attendees in addressing problems with power plant performance and identifying cost-effective solutions for achieving and sustaining heat rate ...

2013-04-05T23:59:59.000Z

9

Operational dose rate visualization techniques  

SciTech Connect

The analysis of the gamma ray dose rate in the vicinity of a radiation source can be greatly aided by the use of recent state-of-the-art visualization techniques. The method involves calculating dose rates at thousands of locations within a complex geometry system. This information is then processed to create contour plots of the dose rate. Additionally, when these contour plots are created, animations can be created that dynamically display the dose rate as the shields or sources are moved.

Schwarz, R.A.; Morford, R.J.; Carter, L.L.; Jones, G.B.; Greenborg, J.

1994-01-01T23:59:59.000Z

10

Evaluation of Methodologies to Provide Comparative Heat Rates  

Science Conference Proceedings (OSTI)

Power generating companiesand even more so, their coal-fired facilitieshave struggled with the comparison of heat rate values from different periods of time. Comparing a unit's July heat rate to that recorded in January has been difficult because of several factors. First, the ambient temperatures are significantly different and manifest in operational and performance changes whose adjustments, although understood, contain uncertainty. The additional effects of variations in capacity and load following f...

2012-03-13T23:59:59.000Z

11

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

12

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 +

13

Survey of Impacts of Environmental Controls on Plant Heat Rate  

Science Conference Proceedings (OSTI)

Environmental controls for sulfur and nitrogen oxides, particulates, mercury, and other pollutants reduce the efficiency of power plants. This report documents the impacts of state-of-the-art environmental controls on power plant heat rate and identifies ways these impacts may be reduced through operating and design changes.

2009-12-07T23:59:59.000Z

14

Radiative Heating Rates for Saharan Dust  

Science Conference Proceedings (OSTI)

A combined longwave and shortwave radiative transfer model was used to determine effects of Saharan dust on the radiative fluxes and heating/cooling rates in the atmosphere. Cases are treated for cloud-free and overcast conditions over the ocean ...

Toby N. Carlson; Stanley G. Benjamin

1980-01-01T23:59:59.000Z

15

Self-consistent microwave plasma heating rates  

SciTech Connect

Under conditions within a hot overdense plasma corona where the field frequency is much less than the electron plasma frequency and the field period is much less than the hydrodynamic expansion time it is shown that electron field reversal heating can exceed the combined classical heating rates due to inverse bremsstrahlung (skin effect) and field pressure (PdV) by a factor approximately v/ sub e//2v/sub i/ (half the ratio of electron and ion thermal velocities). In particular this rate can exceed the inertial expansion cooling rate at a collisionless corona density of approximately 1 percent solid core density and could be realized experimentally at core temperatures approximately 3--5 keV and microwave field intensities approximately 1 MG. (auth)

Ensley, D.L.; White, R.H.

1975-10-01T23:59:59.000Z

16

Renewable Combined Heat and Power Dairy Operations  

E-Print Network (OSTI)

horsepower Guascor model SFGLD-560 biogas-fired lean burn internal combustion (IC) engine and generator set and modify the existing biogas toelectricity combined heat and power (CHP) system operated at Fiscalini bacteria to remove hydrogen sulfide presented in the biogas. Source: Fiscalini Farms Term: March 2011

17

Design and demonstration of heat pipe cooling for NASP and evaluation of heating methods at high heating rates  

SciTech Connect

An evaluation of two heating methods for demonstration of NASP leading edge heat pipe technology was conducted. The heating methods were and rf induction heated plasma jet and direct rf induction. Tests were conducted to determine coupling from the argon plasma jet on a surface physically similar to a heat pipe. A molybdenum tipped calorimeter was fabricated and installed in an rf induction heated plasma jet for the test. The calorimetric measurements indicated a maximum power coupling of approximately 500 W/cm{sup 2} with the rf plasma jet. The effect of change in gas composition on the heating rate was investigated using helium. An alternative to the plasma heating of a heat pipe tip, an rf concentrator was evaluated for coupling to the hemispherical tip of a heat pipe. A refractory metal heat pipe was designed, fabricated, and tested for the evaluation. The heat pipe was designed for operation at 1400 to 1900 K with power input to 1000 W/cm{sup 2} over a hemispherical nose tip. Power input of 800 W/cm{sup 2} was demonstrated using the rf concentrator. 2 refs., 13 figs.

Merrigan, M.A.; Sena, J.T.

1989-01-01T23:59:59.000Z

18

Operating and Maintaining Your Heat Pump | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Operating and Maintaining Your Heat Pump Operating and Maintaining Your Heat Pump Operating and Maintaining Your Heat Pump June 24, 2012 - 3:22pm Addthis Changing filters regularly is an important part of maintaining a heat pump system. | Photo courtesy of ©iStockphoto/BanksPhotos Changing filters regularly is an important part of maintaining a heat pump system. | Photo courtesy of ©iStockphoto/BanksPhotos What does this mean for me? Learn to operate and maintain your heat pump system properly to maximize energy and money savings. You can do many operational and maintenance tasks yourself. Proper operation of your heat pump will save energy. Do not set back the heat pump's thermostat if it causes the backup heating to come on -- backup heating systems are usually more expensive to operate. Continuous indoor

19

High Heating Rate Thermal Desorption for Molecular Surface ...  

High Heating Rate Thermal Desorption for Molecular Surface Sampling Note: The technology described above is an early stage opportunity. Licensing ...

20

Table A6. Approximate Heat Rates for Electricity, and Heat Content ...  

U.S. Energy Information Administration (EIA)

State energy information, detailed and overviews. Maps. ... Table A6. Approximate Heat Rates for Electricity, and Heat Content of Electricity, 1949-2011

Note: This page contains sample records for the topic "operating heat rate" 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

Rainfall and Radiative Heating Rates from TOGA COARE Atmospheric Budgets  

Science Conference Proceedings (OSTI)

Atmospheric heat and moisture budgets are used to determine rainfall and radiative heating rates over the western Pacific warm pool during the Tropical Ocean Global Atmosphere Coupled Ocean–Atmosphere Response Experiment (TOGA COARE). Results are ...

Richard H. Johnson; Paul E. Ciesielski

2000-05-01T23:59:59.000Z

22

Methods to Mitigate the Effect of Increased Cycling and Load Following on Heat Rate  

Science Conference Proceedings (OSTI)

Most of the U.S. coal-fired plants currently in service were designed for baseload operation. Today, however, actual generation conditions dictate that many of these units operate in a continuous transient mode, following generation demand. As such, they often experience large load changes throughout the day that result in a poorer plant heat rate. Reducing the throttle pressure, also known as sliding pressure, reduces throttling losses and is a potential method to reduce the heat rate penalties ...

2012-12-14T23:59:59.000Z

23

Evaluation of Peak Heat Release Rates in Electrical Cabinet Fires  

Science Conference Proceedings (OSTI)

The purpose of this report is to reanalyze the peak heat release rates (HRRs) from fires occurring in electrical cabinets of nuclear power plants.

2012-02-23T23:59:59.000Z

24

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

NLE Websites -- All DOE Office Websites (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...

25

Definition: Rated Electrical Operating Conditions | Open Energy...  

Open Energy Info (EERE)

operate.1 Related Terms system References Glossary of Terms Used in Reliability Standards An LikeLike UnlikeLike You like this.Sign Up to see what your friends like. inline...

26

Heat Rate Improvement Reference Manual: Training Guidelines  

Science Conference Proceedings (OSTI)

Performance optimization of fossil power plants has always been a high priority within the electric power industry. However, it has become of paramount importance in meeting the challenges mandated by operating within a competitive environment. Recently, many power producers have downsized and currently lack experienced staff required to maintain optimal performance. Thus, a resource was needed to capture the lost experience to aid in the retaining of less experienced personnel. The objective of this pro...

1999-12-07T23:59:59.000Z

27

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

NLE Websites -- All DOE Office Websites (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

28

Solar Heating Rates: The Importance of Spherical Geometry  

Science Conference Proceedings (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

29

Radiative Heating and Cooling Rates in the Middle Atmosphere  

Science Conference Proceedings (OSTI)

One of the limitations to the accurate calculation of radiative heating and cooling rates in the stratosphere and mesosphere has been the lack of accurate data on the atmospheric temperature and composition. Data from the LIMS experiment on ...

John C. Gille; Lawrence V. Lyjak

1986-10-01T23:59:59.000Z

30

Evaluation of Fuel Quality Impacts on Heat Rate  

Science Conference Proceedings (OSTI)

The drive to leverage fuel switching to meet more stringent SO2 and NOX emissions requirements has led to both a reduction in power station efficiency and a poorer net plant heat rate (NPHR) in many cases. The root causes include higher fuel moisture content, lower fuel energy content, poorer combustion efficiency, increased station service, and decreased unit capability. This report demonstrates the sensitivity of the key metrics of power station efficiency and heat rate to coal quality parameters, vari...

2010-12-09T23:59:59.000Z

31

Turbine Cycle Heat Rate Monitoring: Technology and Application  

Science Conference Proceedings (OSTI)

Research has been completed on available technology for monitoring turbine cycle heat rate and factors affecting the successful deployment of this technology in fossil generating plants. Information has been gathered from interviews with experienced industry plant staff and vendors. Trends were noted and are described in this report. The report is recommended as guidance for power generation fleets and individual plants seeking to establish a successful program for heat rate reduction.

2006-12-20T23:59:59.000Z

32

Research of Heat Storage Tank Operation Modes in Cogeneration Plant.  

E-Print Network (OSTI)

??The dissertation investigates typical operation modes of the heat storage tank in the small-scale cogeneration (CHP) plant, analyses formation of thermal stratifi-cation in such storage… (more)

Streckien?, Giedr?

2011-01-01T23:59:59.000Z

33

Description and operation of Haakon School geothermal-heating system  

SciTech Connect

To encourage the development of hydrothermal energy, twenty-three demonstration projects were funded. The Haakon School project is one of twelve such projects. The geothermal direct-use heating system at the Haakon School complex in Philip, South Dakota is described and information gained during approximately three heating seasons of operation is presented.

Childs, F.W.; Kirol, L.D.; Sanders, R.D.; McLatchy, M.J.

1983-10-01T23:59:59.000Z

34

Coal plasticity at high heating rates and temperatures  

SciTech Connect

The broad objective of this project is to obtain improved, quantitative understanding of the transient plasticity of bituminous coals under high heating rates and other reaction and pretreatment conditions of scientific and practical interest. To these ends the research plan is to measure the softening and resolidification behavior of two US bituminous coals with a rapid-heating, fast response, high-temperature coal plastometer, previously developed in this laboratory. Specific measurements planned for the project include determinations of apparent viscosity, softening temperature, plastic period, and resolidificationtime for molten coal: (1) as a function of independent variations in coal type, heating rate, final temperature, gaseous atmosphere (inert, 0{sub 2} or H{sub 2}), and shear rate; and (2) in exploratory runs where coal is pretreated (preoxidation, pyridine extraction, metaplast cracking agents), before heating. The intra-coal inventory and molecular weight distribution of pyridine extractables will also be measured using a rapid quenching, electrical screen heater coal pyrolysis reactor. The yield of extractables is representative of the intra-coal inventory of plasticing agent (metaplast) remaining after quenching. Coal plasticity kinetics will then be mathematically modeled from metaplast generation and depletion rates, via a correlation between the viscosity of a suspension and the concentration of deformable medium (here metaplast) in that suspension. Work during this reporting period has been concerned with re-commissioning the rapid heating rate plastometer apparatus.

Darivakis, G.S.; Peters, W.A.; Howard, J.B.

1990-01-01T23:59:59.000Z

35

Status of the Broadband Heating Rate Profile (BBHRP) VAP  

NLE Websites -- All DOE Office Websites (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.

36

Retrofits for Improved Heat Rate and Availability: Circulating Water Heat Recovery Retrofits  

Science Conference Proceedings (OSTI)

Circulating water heat recovery is a means of directly increasing the thermal efficiency of a power plant. If only fuel savings are considered, the economic benefit is often only marginal. However, when increased megawatt output and heat-rate improvements are included in the economic analysis, such retrofits can be attractive, with break-even fuel costs sometimes approaching $1/million Btu.

1990-11-20T23:59:59.000Z

37

Demonstration of EPRI Heat Rate Guidelines at Southern California Edison Ormond Beach Unit 2  

Science Conference Proceedings (OSTI)

Using EPRI's heat rate improvement guidelines, Southern California Edison Company (SCE) developed a heat rate improvement program and realized significant fuel cost reduction. Other utilities can follow SCE's example to develop their own effective heat rate improvement programs.

1992-10-01T23:59:59.000Z

38

Mold Heating and Cooling Pump Package Operator Interface Controls Upgrade  

SciTech Connect

The modernization of the Mold Heating and Cooling Pump Package Operator Interface (MHC PP OI) consisted of upgrading the antiquated single board computer with a proprietary operating system to off-the-shelf hardware and off-the-shelf software with customizable software options. The pump package is the machine interface between a central heating and cooling system that pumps heat transfer fluid through an injection or compression mold base on a local plastic molding machine. The operator interface provides the intelligent means of controlling this pumping process. Strict temperature control of a mold allows the production of high quality parts with tight tolerances and low residual stresses. The products fabricated are used on multiple programs.

Josh A. Salmond

2009-08-07T23:59:59.000Z

39

Table A6. Approximate Heat Rates for Electricity, and Heat Content ...  

U.S. Energy Information Administration (EIA)

Total Fossil Fuels 6,7: ... 7 The fossil-fuels heat rate is used as the thermal conversion factor for ... approximate the quantity of fossil fuels replaced by these ...

40

Design and operation of solar thermal heat transfer systems  

Science Conference Proceedings (OSTI)

The importance of heat transfer systems in the collection and use of solar energy is discussed. The success or failure of many solar energy systems has been determined by the design of the heat transfer system. This report includes a short summary of some of the DOE sponsored solar industrial process heat sites. From the design, construction, and operation of these systems many lessons were learned which will be important to designers and potential users of solar thermal systems. Also included is a discussion of solar collector foundation over-design that has increased the collector system costs.

Rush, E.E.

1985-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "operating heat rate" 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

Parametric Analysis of a 6500-Btu/kWh Heat Rate Dispersed Generator  

Science Conference Proceedings (OSTI)

Cost and performance assessments of two alternative system designs for a 2-MW molten carbonate fuel cell power plant yielded encouraging results: a 6500-Btu/kWh heat rate and a total plant investment of $1200-$1300/kW. Differences between the two designs establish a permissible range of operating conditions for the fuel cell that will help guide its development.

1985-08-14T23:59:59.000Z

42

Sensitivity of Radiative Fluxes and Heating Rates to Cloud Microphysics  

NLE Websites -- All DOE Office Websites (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

43

Rate of Change of Heat Storage of the World Ocean  

Science Conference Proceedings (OSTI)

Results or a Fourier analysis of climatological fields of the monthly rate of change of heat storage for the world ocean are presented. The amplitude and Phase of the first harmonic are shown, as well as the percent variance of the annual cycle ...

Sydney Levitus

1987-04-01T23:59:59.000Z

44

Entirely passive heat pipe apparatus capable of operating against gravity  

DOE Patents (OSTI)

The disclosure is directed to an entirely passive heat pipe apparatus capable of operating against gravity for vertical distances in the order of 3 to 7 meters and more. A return conduit into which an inert gas is introduced is used to lower the specific density of the working fluid so that it may be returned a greater vertical distance from condenser to evaporator.

Koenig, Daniel R. (Santa Fe, NM)

1982-01-01T23:59:59.000Z

45

Existing and Past Methods of Test and Rating Standards Related to Integrated Heat Pump Technologies  

Science Conference Proceedings (OSTI)

This report evaluates existing and past US methods of test and rating standards related to electrically operated air, water, and ground source air conditioners and heat pumps, 65,000 Btu/hr and under in capacity, that potentiality incorporate a potable water heating function. Two AHRI (formerly ARI) standards and three DOE waivers were identified as directly related. Six other AHRI standards related to the test and rating of base units were identified as of interest, as they would form the basis of any new comprehensive test procedure. Numerous other AHRI and ASHRAE component test standards were also identified as perhaps being of help in developing a comprehensive test procedure.

Reedy, Wayne R. [Sentech, Inc.

2010-07-01T23:59:59.000Z

46

Operation and design of selected industrial process heat field tests  

DOE Green Energy (OSTI)

The DOE program of solar industrial process heat field tests has shown solar energy to be compatible with numerous industrial needs. Both the operational projects and the detailed designs of systems that are not yet operational have resulted in valuable insights into design and hardware practice. Typical of these insights are the experiences discussed for the four projects reviewed. Future solar IPH systems should benefit greatly not only from the availability of present information, but also from the wealth of operating experience from projects due to start up in 1981.

Kearney, D. W.

1981-02-01T23:59:59.000Z

47

Heat exchanger efficiently operable alternatively as evaporator or condenser  

DOE Patents (OSTI)

A heat exchanger adapted for efficient operation alternatively as evaporator or condenser and characterized by flexible outer tube having a plurality of inner conduits and check valves sealingly disposed within the outer tube and connected with respective inlet and outlet master flow conduits and configured so as to define a parallel flow path for a first fluid such as a refrigerant when flowed in one direction and to define a serpentine and series flow path for the first fluid when flowed in the opposite direction. The flexible outer tube has a heat exchange fluid, such as water, flowed therethrough by way of suitable inlet and outlet connections. The inner conduits and check valves form a package that is twistable so as to define a spiral annular flow path within the flexible outer tube for the heat exchange fluid. The inner conduits have thin walls of highly efficient heat transfer material for transferring heat between the first and second fluids. Also disclosed are specific materials and configurations.

Ecker, Amir L. (Dallas, TX)

1981-01-01T23:59:59.000Z

48

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 +

49

AFBC - operation of small scale demonstration for greenhouse heating  

SciTech Connect

A 2.2 million Btu/hr unit prototype AFBC system was installed in 1995 at Cedar Lane Farms, a commercial nursery in Ohio. The AFBC is in operation and is heating hot water for greenhouse temperature control. A team consisting of the Energy and Environmental Research Corporation, the Ohio Agricultural Research and Development Center of Ohio State University and the Will-Burt Company developed this technology with funding support from the Ohio Coal Development Office and the U.S. Department of Energy. The system is fully automated with little operator attention being required. Operating experience at Cedar Lane Farms has shown that only 2 hours per day of operation attention is required for the system. The system includes flyash/sorbent reinjection and underbed coal/limestone feed. These features provide for good limestone utilization; a Ca/S (in coal) ratio of 2.5 will maintain an SO{sub 2} emissions level of 1.2 lb/10{sup 6} Btu when burning high sulfur (3.2%) Ohio coal. A baghouse is used to control particulate emissions. Based on the success of the prototype unit, a design has been recently completed for a commercial size 10 x 10{sup 6} Btu/hr capacity range. Multiple AFBC units can be used to provide larger heat outputs. Potential coal-fired AFBC users include institutions (schools, hospitals, prisons, government), light industry (agricultural, food processing), commercial users (shopping centers), and large residential users (apartment complexes). 6 figs., 1 tab.

Ashworth, R.A.; Plessinger, D.A.; Webner, R.L.; Machamer, T.

1996-12-31T23:59:59.000Z

50

TRANSIENT HEAT TRANSFER ANALYSIS FOR SRS RADIOACTIVE TANK OPERATION  

SciTech Connect

The primary objective of the present work is to perform a heat balance study for type-I waste tank to assess the impact of using submersible mixer pumps during waste removal. The temperature results calculated by the model will be used to evaluate the temperatures of the slurry waste under various tank operating conditions. A parametric approach was taken to develop a transient model for the heat balance study for type-I waste tanks such as Tank 11, during waste removal by SMP. The tank domain used in the present model consists of two SMP?s for sludge mixing, one STP for the waste removal, cooling coil system with 36 coils, and purge gas system. The sludge waste contained in Tank 11 also has a decay heat load of about 43 W/m{sup 3} mainly due to the emission of radioactive gamma rays. All governing equations were established by an overall energy balance for the tank domain, and they were numerically solved. A transient heat balance model used single waste temperature model, which represents one temperature for the entire waste liquid domain contained in the tank at each transient time.

Lee, S.

2013-06-27T23:59:59.000Z

51

A Simple Strategy for Optimal Operation of Heat Exchanger V. LERSBAMRUNGSUK1  

E-Print Network (OSTI)

A Simple Strategy for Optimal Operation of Heat Exchanger Networks V. LERSBAMRUNGSUK1 , S for optimal operation of heat exchanger networks. Optimal operation in this context requires that 1) all of heat exchanger networks are analyzed and used to identify if the operation is structurally feasible

Skogestad, Sigurd

52

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

E-Print Network (OSTI)

#12;forth through the heat exchangers, thereby phasing the rates at which heat is absorbed balance as shown in Fig. 3 still indi- cated a greater heat loss to the engine coolant than predicted. This was caused by excessive heat leak- age from the hot to the cold working spaces, primarily by the flow leakage

Oak Ridge National Laboratory

53

The Influence of Different Inflow Water Rate and Temperature on Heat Exchange Performance of Underground Heat Pump  

Science Conference Proceedings (OSTI)

in the paper, the influence of different inflow water rate and temperature on heat exchange performance of underground heat pump were discussed by experiment, two vital parameters was defined to measure the properties of ground heat exchanger: Energy ... Keywords: heat pump, underground tube, influential factors, parameters

Zheng Min; Li Bai-yi

2011-11-01T23:59:59.000Z

54

Consumer benefits of electricity-price-driven heat pump operation in future smart grids  

Science Conference Proceedings (OSTI)

This paper describes the financial benefits of consumers while applying different operating modes to their heat pump. In order to evaluate the different operating modes a single family house with heating system has been modeled and simulated with different ...

Christoph Molitor; Ferdinanda Ponci; Antonello Monti; Davide Cali; Dirk Muller

2011-11-01T23:59:59.000Z

55

NGNP/HTE full-power operation at reduced high-temperature heat exchanger temperatures.  

Science Conference Proceedings (OSTI)

Operation of the Next Generation Nuclear Plant (NGNP) with reduced reactor outlet temperature at full power was investigated for the High Temperature Electrolysis (HTE) hydrogen-production application. The foremost challenge for operation at design temperature is achieving an acceptably long service life for heat exchangers. In both the Intermediate Heat Exchanger (IHX) and the Process Heat Exchanger (PHX) (referred to collectively as high temperature heat exchangers) a pressure differential of several MPa exists with temperatures at or above 850 C. Thermal creep of the heat exchanger channel wall may severely limit heat exchanger life depending on the alloy selected. This report investigates plant performance with IHX temperatures reduced by lowering reactor outlet temperature. The objective is to lower the temperature in heat transfer channels to the point where existing materials can meet the 40 year lifetime needed for this component. A conservative estimate for this temperature is believed to be about 700 C. The reactor outlet temperature was reduced from 850 C to 700 C while maintaining reactor power at 600 MWt and high pressure compressor outlet at 7 MPa. We included a previously reported design option for reducing temperature at the PHX. Heat exchanger lengths were adjusted to reflect the change in performance resulting from coolant property changes and from resizing related to operating-point change. Turbomachine parameters were also optimized for the new operating condition. An integrated optimization of the complete system including heat transfer equipment was not performed. It is estimated, however, that by performing a pinch analysis the combined plant efficiency can be increased from 35.5 percent obtained in this report to a value between 38.5 and 40.1 percent. Then after normalizing for a more than three percent decrease in commodities inventory compared to the reference plant, the commodities-normalized efficiency lies between 40.0 and 41.3. This compares with a value of 43.9 for the reference plant. This latter plant has a reactor outlet temperature of 850 C and the two high temperature heat exchangers. The reduction in reactor outlet temperature from 850 C to 700 C reduces the tritium permeability rate in the IHX metal by a factor of three and thermal creep by five orders of magnitude. The design option for reducing PHX temperature from 800 C to 200 C reduces the permeability there by three orders of magnitude. In that design option this heat exchanger is the single 'choke-point' for tritium migration from the nuclear to the chemical plant.

VIlim, R.; Nuclear Engineering Division

2009-03-12T23:59:59.000Z

56

SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer  

NLE Websites -- All DOE Office Websites (Extended Search)

High Operating Temperature Liquid High Operating Temperature Liquid Metal Heat Transfer Fluids to someone by E-mail Share SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer Fluids on Facebook Tweet about SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer Fluids on Twitter Bookmark SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer Fluids on Google Bookmark SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer Fluids on Delicious Rank SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer Fluids on Digg Find More places to share SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer Fluids on AddThis.com... Concentrating Solar Power Systems Components Competitive Awards

57

Energy ratings for metal oxide varistors under repetitively pulsed operation  

DOE Green Energy (OSTI)

Nonlinear resistors can be used to improve the energy transfer efficiency of inductive energy storage systems that use resistive transfer elements. Improved energy transfer efficiency can result in significant cost savings in some large systems if the cost of the nonlinear resistor is less than the cost of the energy storage and charging hardware that the resistor replaces. This report describes experimental tests that were done to determine appropriate energy ratings for ZnO Metal Oxide Varistors (MOVs) for pulsed conditions from 10 to 20 ms long. Tests were performed first on single MOV units which were forced to failure in a small number of shots. Then several sets of matched pairs were operated under identical conditions to investigate current sharing and the statistics of failure. Test results show that the standard rating method used by manufacturers relating peak current, pulse length, and expected lifetime are adequate, but somewhat conservative. The manufacturers' energy ratings project to a very economical nonlinear transfer resistor. 7 refs., 4 figs., 1 tab.

Melton, J.G.

1989-01-01T23:59:59.000Z

58

PERFORMANCE OF A SINGLE-ROW HEAT EXCHANGER AT LOW IN-TUBE FLOW RATES  

E-Print Network (OSTI)

PERFORMANCE OF A SINGLE-ROW HEAT EXCHANGER AT LOW IN-TUBE FLOW RATES A Thesis Submitted April 1995 #12;PERFORMANCE OF A SINGLE-ROW HEAT EXCHANGER AT LOW IN-TUBE FLOW RATES by Xiangwei Zhao Abstract The steady and time-dependentbehavior of a single-row heat exchanger with water and air in the in

Sen, Mihir

59

Study of Operating Control Strategies for Hybrid Ground Source Heat Pump System with Supplemental Cooling Tower  

Science Conference Proceedings (OSTI)

Ground source heat pump for cooling-dominated commercial buildings may utilize supplemental cooling towers to reduce system first cost and to improve system performance. The use of hybrid ground source heat pump (HGSP) can reduce the size of the ground-loop ... Keywords: hybrid ground source heat pump, supplement heat rejection, control strategies, operating performance

Wang Jinggang; Gao Xiaoxia; Yin Zhenjiang; Li Fang

2009-07-01T23:59:59.000Z

60

Evaluation of Methodologies for Real-Time Incremental Heat Rate Determination  

Science Conference Proceedings (OSTI)

Reduced staffing, tighter budgets, ISOs, and increased competition have created the need for maintaining up-to-date incremental heat rate information. Combining recent advances in analytics with modern performance monitoring packages and data historians may provide the capability for closer-to-real-time incremental heat rate determination. Many power generating companies either rely on historic data or slow and labor intensive testing to establish incremental heat rate curves. Those curves are ...

2013-11-26T23:59:59.000Z

Note: This page contains sample records for the topic "operating heat rate" 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

Investigation of several critical issues in screen mesh heat pipe manufacturing and operation.  

E-Print Network (OSTI)

??The PhD thesis with the title “Investigation of several critical issues in screen mesh heat pipe manufacturing and operation” presented hereafter describes work carried out… (more)

Engelhardt, Andreas

2010-01-01T23:59:59.000Z

62

EFFECT OF HEATING RATE ON THE THERMODYNAMIC PROPERTIES OF PULVERIZED COAL  

SciTech Connect

This final technical report describes work performed under DOE Grant No. DE-FG22-96PC96224 during the period September 24, 1996 to September 23, 1999 which covers the entire performance period of the project. During this period, modification, alignment, and calibration of the measurement system, measurement of devolatilization time-scales for single coal particles subjected to a range of heating rates and temperature data at these time-scales, and analysis of the temperature data to understand the effect of heating rates on coal thermal properties were carried out. A new thermodynamic model was developed to predict the heat transfer behavior for single coal particles using one approach based on the analogy for thermal property of polymers. Results of this model suggest that bituminous coal particles behave like polymers during rapid heating on the order of 10{sup 4}-10{sup 5} K/s. At these heating rates during the early stages of heating, the vibrational part of the heat capacity of the coal molecules appears to be still frozen but during the transition from heat-up to devolatilization, the heat capacity appears to attain a sudden jump in its value as in the case of polymers. There are a few data available in the coal literature for low heating rate experiments (10{sup 2}-10{sup 3} K/s) conducted by UTRC, our industrial partner, in this project. These data were obtained for a longer heating duration on the order of several seconds as opposed to the 10 milliseconds heating time of the single particle experiments discussed above. The polymer analogy model was modified to include longer heating time on the order of several seconds to test these data. However, the model failed to predict these low heating rate data. It should be noted that UTRC's work showed reasonably good agreement with Merrick model heat capacity predictions at these low heating rates, but at higher heating rates UTRC observed that coal thermal response was heat flux dependent. It is concluded that at combustion level heating rates (10{sup 4}-10{sup 5} K/s) coal structural changes are delayed and attendant increases in heat capacity and thermal conductivity are pushed to higher temperatures or require significant hold times to become manifest.

Ramanathan Sampath

2000-01-01T23:59:59.000Z

63

The New French Operational Polarimetric Radar Rainfall Rate Product  

Science Conference Proceedings (OSTI)

In 2012 the Météo France metropolitan operational radar network consists of 24 radars operating at C and S bands. In addition, a network of four X-band gap-filler radars is being deployed in the French Alps. The network combines polarimetric and ...

Jordi Figueras i Ventura; Pierre Tabary

2013-08-01T23:59:59.000Z

64

Control Structure Selection for Optimal Operation of a Heat Exchanger Network  

E-Print Network (OSTI)

Control Structure Selection for Optimal Operation of a Heat Exchanger Network Johannes J--We consider the control structure design for a heat exchanger network (HEN), where a stream is split of temperature measurements. Index Terms--Control structure selection, Self-optimizing con- trol, Heat exchanger

Skogestad, Sigurd

65

High Operating Temperature Heat Transfer Fluids for Solar Thermal...  

NLE Websites -- All DOE Office Websites (Extended Search)

Heat Transfer Fluids for Solar Thermal Power Generation UCLA, UCB, Yale Award Number: DE-EE0005941 | January 9, 2013 | Sungtaek Ju 1.1 Thermochemistry modeling Identified promising...

66

Method for starting and operating an advanced regenerative parallel compound dual fluid heat engine-advanced Cheng cycle(ACC)  

SciTech Connect

In a Cheng cycle, dual fluid heat engine of the type is described having: (i) a gas turbine engine including a compressor for compressing a first working fluid, having a compressor outlet, a combustion chamber in fluid communication with the compressor outlet, a turbine unit having an inlet in fluid communication with the combustion chamber for performing work by expansion of working fluid, and a turbine exhaust; (ii) a heat recovery steam generator coupled to the turbine exhaust for heating a second working fluid having a superheater with an outlet and an inlet, an evaporator having an outlet coupled to the superheater inlet and an evaporator inlet, a heat recovery boiler between the evaporator inlet and outlet having a drum; (iii) an injector for introducing heated second working fluid from the heat recovery steam generator into the gas turbine; (iv) a coolant inlet port for introducing coolant to at least one of turbine nozzles and blades in the gas turbine; and (v) control valve means for selectively throttling flow rate of second working fluid into the gas turbine connected upstream of the injector; (vi) a compressed gas source and pressure regulator selectively in communication with the drum; (vii) a sensor system coupled to gas turbine engine and the heat recovery steam generator for temperature and pressure detection; and (viii) a control system for operating fuel flow to the gas turbine; a method of operation of the heat engine comprising: (a) initializing start conditions in the gas turbine engine and the heat recovery steam generator with the control system; (b) setting the control valve means for idle flow condition of the heat engine; (c) pressurizing the drum with the compressed gas source, (d) starting the gas turbine engine from idle to full load; (e) throttling second working fluid flow rate with the control valve means and shutting off the compressed gas source.

Cheng, D.Y.

1993-08-10T23:59:59.000Z

67

Relationship between the shear viscosity and heating rate in metallic glasses below the glass transition  

Science Conference Proceedings (OSTI)

It has been shown that first-order irreversible structural relaxation with distributed activation energies must lead to a linear decrease of the logarithm of Newtonian shear viscosity with the logarithm of heating rate upon linear heating of glass. Such a behavior is indeed observed in the experiments on metallic glasses. Structural relaxation-induced viscous flow leads to infra-low-frequency Maxwell viscoelastic internal friction, which is predicted to increase with the heating rate.

Khonik, Vitaly A.; Kobelev, N. P. [Department of General Physics, State Pedagogical University, Lenin Street 86, 394043 Voronezh (Russian Federation); Institute for Solid State Physics, Chernogolovka, 142432 Moscow District (Russian Federation)

2008-04-01T23:59:59.000Z

68

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

NLE Websites -- All DOE Office Websites (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

69

High energy bursts from a solid state laser operated in the heat capacity limited regime  

DOE Patents (OSTI)

High energy bursts are produced from a solid state laser operated in a heat capacity limited regime. Instead of cooling the laser, the active medium is thermally well isolated. As a result, the active medium will heat up until it reaches some maximum acceptable temperature. The waste heat is stored in the active medium itself. Therefore, the amount of energy the laser can put out during operation is proportional to its mass, the heat capacity of the active medium, and the temperature difference over which it is being operated. The high energy burst capacity of a heat capacity operated solid state laser, together with the absence of a heavy, power consuming steady state cooling system for the active medium, will make a variety of applications possible. Alternately, cooling takes place during a separate sequence when the laser is not operating. Industrial applications include new material working processes.

Albrecht, Georg (Livermore, CA); George, E. Victor (Livermore, CA); Krupke, William F. (Pleasanton, CA); Sooy, Walter (Pleasanton, CA); Sutton, Steven B. (Manteca, CA)

1996-01-01T23:59:59.000Z

70

High energy bursts from a solid state laser operated in the heat capacity limited regime  

DOE Patents (OSTI)

High energy bursts are produced from a solid state laser operated in a heat capacity limited regime. Instead of cooling the laser, the active medium is thermally well isolated. As a result, the active medium will heat up until it reaches some maximum acceptable temperature. The waste heat is stored in the active medium itself. Therefore, the amount of energy the laser can put out during operation is proportional to its mass, the heat capacity of the active medium, and the temperature difference over which it is being operated. The high energy burst capacity of a heat capacity operated solid state laser, together with the absence of a heavy, power consuming steady state cooling system for the active medium, will make a variety of applications possible. Alternately, cooling takes place during a separate sequence when the laser is not operating. Industrial applications include new material working processes. 5 figs.

Albrecht, G.; George, E.V.; Krupke, W.F.; Sooy, W.; Sutton, S.B.

1996-06-11T23:59:59.000Z

71

Nuclear mass inventory, photon dose rate and thermal decay heat of spent research reactor fuel assemblies  

SciTech Connect

This document has been prepared to assist research reactor operators possessing spent fuel containing enriched uranium of United States origin to prepare part of the documentation necessary to ship this fuel to the United States. Data are included on the nuclear mass inventory, photon dose rate, and thermal decay heat of spent research reactor fuel assemblies. Isotopic masses of U, Np, Pu and Am that are present in spent research reactor fuel are estimated for MTR, TRIGA and DIDO-type fuel assembly types. The isotopic masses of each fuel assembly type are given as functions of U-235 burnup in the spent fuel, and of initial U-235 enrichment and U-235 mass in the fuel assembly. Photon dose rates of spent MTR, TRIGA and DIDO-type fuel assemblies are estimated for fuel assemblies with up to 80% U-235 burnup and specific power densities between 0.089 and 2.857 MW/kg[sup 235]U, and for fission product decay times of up to 20 years. Thermal decay heat loads are estimated for spent fuel based upon the fuel assembly irradiation history (average assembly power vs. elapsed time) and the spent fuel cooling time.

Pond, R.B.; Matos, J.E.

1996-12-31T23:59:59.000Z

72

Geothermal Heat Pump Systems in Schools: Construction, Maintenance and Operating Costs  

Science Conference Proceedings (OSTI)

Geothermal heat pumping and cooling systems are still not widely used to heat and cool buildings. They are an unknown to most architects and engineers. The electric utility industry has recognized them as being a very energy-efficient way to heat and cool buildings using electricity. The Tennessee Valley Authority (TVA) has assisted in design and installation of many geothermal systems, particularly in school buildings. With a number of geothermal heat pump systems in schools in operation in the TVA regi...

2000-12-13T23:59:59.000Z

73

Operation characteristics of cylindrical miniature grooved heat pipe using aqueous CuO nanofluids  

Science Conference Proceedings (OSTI)

An experimental study was performed to investigate the operation characteristics of a cylindrical miniature grooved heat pipe using aqueous CuO nanofluid as the working fluid at some steady cooling conditions. The experiments were carried out under both the steady operation process and the unsteady startup process. The experiment results show that substituting the nanofluid for water as the working fluid can apparently improve the thermal performance of the heat pipe for steady operation. The total heat resistance and the maximum heat removal capacity of the heat pipe using nanofluids can maximally reduce by 50% and increase by 40% compared with that of the heat pipe using water, respectively. For unsteady startup process, substituting the nanofluid for water as the working fluid, cannot only improve the thermal performance, but also reduce significantly the startup time. (author)

Wang, Guo-Shan; Song, Bin; Liu, Zhen-Hua [School of Mechanical Engineering, Shanghai Jiaotong University, 200240 Shanghai (China)

2010-11-15T23:59:59.000Z

74

Dependency of Heat Transfer Rate on the Brinkman Number in Microchannels  

E-Print Network (OSTI)

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 but is not clearly understood yet. This work proposes a new correlation between heat transfer rate and Brinkman number which is nondimensional number of viscosity, flow velocity and temperature. It is expected that the equation proposed by this work can be useful to design microchannel cooling device.

H. S. Park

2008-01-07T23:59:59.000Z

75

High Operating Temperature Liquid Metal Heat Transfer Fluids  

NLE Websites -- All DOE Office Websites (Extended Search)

Liquid Metal Liquid Metal Heat Transfer Fluids UCLA, UCB, Yale DE-EE0005941 | April 15, 2013 | Ju 1.1 Thermochemistry modeling * Continue CALPHAD based calculations to search for optimal ternary alloy compositions. * Initiate development of liquid density models. 1.2 Combinatorial synthesis and characterization * Pipe-Liquid interaction of compositional library * More alloys, alloy additions and effect on liquidus temperatures * Iteratively optimize the compositions. 1.3 Corrosion characterization and mitigation * Tune static corrosion testing systems for testing over an extended period of time. * Perform analysis of the micro mechanical testing on the oxide layers. 1.4 Heat transfer characterization and modeling * Complete the construction of the flow loop and perform experiments to measure

76

Partial fuel stratification to control HCCI heat release rates : fuel composition and other factors affecting pre-ignition reactions of two-stage ignition fuels.  

DOE Green Energy (OSTI)

Homogeneous charge compression ignition (HCCI) combustion with fully premixed charge is severely limited at high-load operation due to the rapid pressure-rise rates (PRR) which can lead to engine knock and potential engine damage. Recent studies have shown that two-stage ignition fuels possess a significant potential to reduce the combustion heat release rate, thus enabling higher load without knock.

Dec, John E.; Sjoberg, Carl-Magnus G.; Cannella, William (Chevron USA Inc.); Yang, Yi; Dronniou, Nicolas

2010-11-01T23:59:59.000Z

77

EFFECT OF HEATING RATE ON THE THERMODYNAMIC PROPERTIES OF PULVERIZED COAL  

Science Conference Proceedings (OSTI)

This semi-annual technical progress report describes work performed under DOE Grant No. DE-FG22-96PC96224 during the period March 24, 1999 to September 23, 1999 which covers the last (sixth) six months of the project. During this reporting period, extraction of devolatilization time-scales and temperature data at these time-scales analyzing the high-speed films taken during the experiments was complete. Also a new thermodynamic model was developed to predict the heat transfer behavior for coal particles subjected to a range of heating rates using one approach based on the analogy of polymers. Sensitivity analyses of this model suggest that bituminous coal particles behave like polymers during rapid heating on the order of 10{sup 4}-10{sup 7} K/s. At these heating rates during the early stages within the first few milliseconds of heating time, the vibrational part of the heat capacity of the coal molecules appears to be still frozen but during the transition from heat-up to devolatization, the heat capacity appears to attain a sudden jump in its value as in the case of polymers. There are few data available in the coal literature for 10{sup 2}-10{sup 3} K/s obtained by UTRC in their previous studies. These data were obtained for a longer heating duration on the order of several seconds as opposed to the 10 milliseconds heating time in the single particle experiments discussed above. The polymer analogy model is being modified to include longer heating time on the order of several seconds to test these data. It is expected that the model might still do a good job in the case of these larger heating time but very low heating rate experiments. Completion of the numerical analysis of the experimental data and preparation of the final report are in progress.

Ramanathan Sampath

1999-11-02T23:59:59.000Z

78

On the Effects of Cumulus Dimensions on Longwave Irradiance and Heating Rate Calculations  

Science Conference Proceedings (OSTI)

A model of a cumulus cloud field, parameterized as right circular cylinders, has been used to estimate the uncertainties in longwave radiation calculations of irradiances and heating rates caused by neglecting the dimensions of the clouds. The ...

Robert G. Ellingson

1982-04-01T23:59:59.000Z

79

The Impact of Polar Stratospheric Clouds on the Heating Rates of the Winter Polar Stratosphere  

Science Conference Proceedings (OSTI)

We have computed the perturbation to the infrared radiative heating rates of the lower stratosphere due to the occurrence of polar stratospheric clouds (PSCs) during the winter season in the Antarctic and Arctic regions. The calculations were ...

James B. Pollack; Christopher P. McKay

1985-02-01T23:59:59.000Z

80

Calculating Monthly Radiative Fluxes and Heating Rates fromMonthly Cloud Observations  

Science Conference Proceedings (OSTI)

The radiative transfer model from NCAR’s general circulation model CCM3 is modified to calculate monthly radiative fluxes and heating rates from monthly observations of cloud properties from the International Satellite Cloud Climatology Project ...

John W. Bergman; Harry H. Hendon

1998-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "operating heat rate" 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

An Efficient Method for Online Calculations of Photolysis and Heating Rates  

Science Conference Proceedings (OSTI)

The authors present a computationally highly efficient method for the online calculation of photolysis and heating rates, which is especially suited for coupled transport–chemistry models. For this purpose, the spectral range 178.6 nm ? ? ? 752.5 ...

J. Landgraf; P. J. Crutzen

1998-03-01T23:59:59.000Z

82

High Operating Temperature Liquid Metal Heat Transfer Fluids (Fact Sheet)  

DOE Green Energy (OSTI)

The University of California, Los Angeles, the University of California, Berkeley, and Yale University is one of the 2012 SunShot CSP R&D awardees for their Multidisciplinary University Research Initiative (MURI): High Operating Temperature (HOT) Fluids. This fact sheet explains the motivation, description, and impact of the project.

Not Available

2012-12-01T23:59:59.000Z

83

Solar heating and cooling of residential buildings: sizing, installation and operation of systems. 1980 edition  

DOE Green Energy (OSTI)

This manual was prepared as a text for a training course on solar heating and cooling of residential buildings. The course and text are directed toward sizing, installation, operation, and maintenance of solar systems for space heating and hot water supply, and solar cooling is treated only briefly. (MHR)

None

1980-09-01T23:59:59.000Z

84

Model of home heating and calculation of rates of return to household energy conservation investment  

Science Conference Proceedings (OSTI)

This study attempts to find out if households' investments on energy conservation yield expected returns. It first builds a home-heating regression model, then uses the results of the model to calculate the rates of return for households' investments on the energy conservation. The home heating model includes housing characteristics, economic and demographic variables, appliance related variables, and regional dummy variables. Housing characteristic variables are modeled according to the specific physical relationship between the house and its heating requirement. Data from the Residential Energy Consumption Survey (RECS) of 1980-1981 is used for the empirical testing of the model. The model is estimated for single-detached family houses separately for three major home-heating fuel types: electricity, natural gas and fuel oil. Four scenarios are used to calculate rates of return for each household. The results show in the Northern areas the rates of return in most of the cases are a lot higher than market interest rates. In the Western and Southern areas, with few exceptions, the rates of return are lower than market interest rates. The variation of heating degree days and energy prices can affect the rates of return up to 20 percentage points.

Hsueh, L.M.

1984-01-01T23:59:59.000Z

85

High energy bursts from a solid state laser operated in the heat capacity limited regime  

DOE Patents (OSTI)

Solid state laser technology is a very well developed field and numerous embodiments and modes of operation have been demonstrated. A more recent development has been the pumping of a solid state laser active medium with an array of diode lasers (diode pumping, for short). These diode pump packages have previously been developed to pump solid state lasers with good efficiency, but low average power. This invention is a method and the resulting apparatus for operating a solid state laser in the heat capacity mode. Instead of cooling the laser, the active medium will heat up until it reaches some maximum acceptable temperature. The waste heat is stored in the active medium itself.

Albrecht, G.; George, E.V.; Krupke, W. [and others

1994-12-31T23:59:59.000Z

86

Development and extended operation of a high power radiation loaded heat pipe  

SciTech Connect

A high temperature, high power molybdenum-lithium heat pipe has been fabricated and tested at 1500 K for 1700 hours with radiant heat rejection. Power throughput during the test was approximately 14 kW, corresponding to an axial flux density of 11 kW/cm/sup 2/ for the 1.59 cm diameter heat pipe. Radial flux density was 70 W/cm/sup 2/ over an evaporator length of 40.0 cm. Condenser length was approximately 150 cm with radiant heat rejection from the condenser to a coaxial water cooled radiation calorimeter. A plasma sprayed, high emissivity coating was used on the condenser surface to increase the radiant heat rejection during the tests. The heat pipe was operated for 514 hours at steady state conditions before being damaged during a planned shutdown for test equipment maintenance. The damage was repaired and the initial 1000 hour test period completed without further incident. After physical examination of the heat pipe at 1000 hours the test was resumed and the heat pipe operated at the same conditions for an additional 700 hours before conclusion of this test phase.

Merrigan, M.A.; Keddy, E.S.; Runyan, J.R.; Martinez, H.E.

1984-06-01T23:59:59.000Z

87

Combined Operation of Solar Energy Source Heat Pump, Low-vale Electricity and Floor Radiant System  

E-Print Network (OSTI)

Today energy sources are decreasing and saving energy conservation becomes more important. Therefore, it becomes an important investigative direction how to use reproducible energy sources in the HVAC field. The feasibility and necessity of using solar energy, low-vale electricity as heat sources in a floor radiant system are analyzed. This paper presents a new heat pump system and discusses its operational modes in winter.

Liu, G.; Guo, Z.; Hu, S.

2006-01-01T23:59:59.000Z

88

Optimal Operation of a Waste Incineration Plant for District Heating Johannes Jaschke, Helge Smedsrud, Sigurd Skogestad*, Henrik Manum  

E-Print Network (OSTI)

Optimal Operation of a Waste Incineration Plant for District Heating Johannes J¨aschke, Helge@chemeng.ntnu.no off-line. This systematic approach is here applied to a waste incineration plant for district heating. In district heating networks, operators usually wish to ob- tain the lowest possible return temperature

Skogestad, Sigurd

89

Evaluation of Next Generation Nuclear Power Plant (NGNP) Intermediate Heat Exchanger (IHX) Operating Conditions  

DOE Green Energy (OSTI)

This report summarizes results of a preliminary evaluation to determine the operating conditions for the Next Generation Nuclear Plant (NGNP) Intermediate Heat Exchanger (IHX) that will transfer heat from the reactor primary system to the demonstration hydrogen production plant(s). The Department of Energy is currently investigating two primary options for the production of hydrogen using a high temperature reactor as the power source. These options are the High Temperature Electrolysis (HTE) and Sulfur-Iodine (SI) thermochemical hydrogen production processes. However, since the SI process relies entirely on process heat from the reactor, while the HTE process relies primarily on electrical energy with only a small amount of process heat required, the design of the IHX is dictated by the SI process heat requirements. Therefore, the IHX operating conditions were defined assuming 50 MWt is available for the production of hydrogen using the SI process. Three configurations for the intermediate loop were evaluated, including configurations for both direct and indirect power conversion systems. The HYSYS process analysis software was used to perform sensitivity studies to determine the influence of reactor outlet temperatures, intermediate loop working fluids (helium and molten salt), intermediate loop pressures, and intermediate loop piping lengths on NGNP performance and IHX operating conditions. The evaluation of NGNP performance included assessments of overall electric power conversion efficiency and estimated hydrogen production efficiency. Based on these evaluations, recommended IHX operating conditions are defined.

E. A. Harvego

2006-04-01T23:59:59.000Z

90

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

E-Print Network (OSTI)

In this paper, life cycle cost analysis (LCCA) of waste heat operated vapour absorption air conditioning system (VARS) incorporated in a building cogeneration system is presented and discussed. The life cycle cost analysis (LCCA) based on present worth cost (PWC) method, which covers the initial costs, operating costs, maintenance costs, replacement costs and salvage values is the useful tool to merit various cooling and power generation systems for building applications. A life cycle of 23 years was used to calculate the PWC of the system for annual operating hours of 8760 and the same is compared with the electric based vapour compression chiller (VCRS) of same capacity. The life cycle cost (LCC) of waste heat operated absorption chiller is estimated to be US $ 1.5 million which is about 71.5 % low compared to electric powered conventional vapour compression chiller. From the analysis it was found that the initial cost of VARS system was 125 % higher than that of VCRS, while the PWC of operating cost of VARS was 78.2 % lower compared to VCRS. The result shows that the waste heat operated VARS would be preferable from the view point of operating cost and green house gas emission reduction.

Saravanan, R.; Murugavel, V.

2010-01-01T23:59:59.000Z

91

Cold End Inserts for Process Gas Waste Heat Boilers Air Products, operates hydrogen production plants, which utilize large waste heat boilers (WHB)  

E-Print Network (OSTI)

Cold End Inserts for Process Gas Waste Heat Boilers Overview Air Products, operates hydrogen production plants, which utilize large waste heat boilers (WHB) to cool process syngas. The gas enters satisfies all 3 design criteria. · Correlations relating our experimental results to a waste heat boiler

Demirel, Melik C.

92

On energy exchange rate and entropy production operators in quantum fluctuation-dissipation relations  

E-Print Network (OSTI)

For quantum systems with externally time-varied Hamiltonians a definition of operators of system's energy change rate (work per unit time) and entropy production observables is suggested and discussed in the context of rigorous statistical equalities (generalized fluctuation-dissipation relations) under the Jordan-symmetrized chronological operator ordering rule.

Yu. E. Kuzovlev

2013-05-15T23:59:59.000Z

93

Tropical Precipitation Rates during SOP-1, FGGE, Estimated from Heat and Moisture Budgets  

Science Conference Proceedings (OSTI)

This study presents global estimates of precipitation rates from 30°N to 30°S, derived from the “apparent” heat source (Q1) and “apparent” moisture sink (Q2) budgets using the NASA Goddard Laboratory for Atmospheres Level III-b analyses collected ...

Catherine B. Pedigo; Dayton G. Vincent

1990-03-01T23:59:59.000Z

94

Scale Dependence of Solar Heating Rates in Convective Cloud Systems with Implications to General Circulation Models  

Science Conference Proceedings (OSTI)

The authors examine 3D solar radiative heating rates within tropical convective–cirrus systems to identify the scales that contribute significantly to the spatial average over a climate model’s grid cell (i.e., its grid mean), and determine their ...

A. M. Vogelmann; V. Ramanathan; I. A. Podgorny

2001-04-01T23:59:59.000Z

95

Heart rate fluctuations in post?operative and brain?death patients  

Science Conference Proceedings (OSTI)

The power spectra of heart rate in patients receiving intensive care were calculated and the relation between gain and frequency discussed. 1/f fluctuations in heart rate can be observed in both post?operative and brain?death patients in the intensive care unit. These results suggested that 1/f fluctuations are a fundamental human phenomenon.

Toshiyo Tamura; Kazuki Nakajima; Tuyoshi Maekawa; Yoshiyuki Soejima; Yasuhiro Kuroda; Akio Tateishi

1993-01-01T23:59:59.000Z

96

EFFECT OF HEATING RATE ON THE THERMODYNAMIC PROPERTIES OF PULVERIZED COAL  

SciTech Connect

This semi-annual technical progress report describes work performed under DOE Grant No. DE-FG22-96PC96224 during the period September 24, 1998 to March 23, 1999 which covers the fifth six months of the project. Devolatilization is an important initial step in virtually all commercial fossil fuel applications such as combustion, gasification, and liquefaction. Characterization of the temperature history of pulverized coal particles under high heating rates, representative of coal combustors, is critical to the understanding of devolatilization. During this reporting period, characterization experiments were continued from the previous reporting period and completed to a total of 28 single coal particles. These particles were caught in the electrodynamic balance and their volume, external surface area, mass, and density were measured. The same single particles were then heated bidirectionally with a pulsed (10 ms pulse width) Nd:YAG laser beams of equal intensity with heating rates (10{sup 4} - 10{sup 7} K/s) representative of coal combustors. The temporal power variation in the laser pulse was monitored for use in the heat transfer analysis by an ultra-fast fiber optic uv light transmitter included in the beam path and coupled to a silicon photodiode. Transient surface temperatures of the particles were measured using a single-color pyrometer. Dynamics of volatile evolution and particle swelling were recorded using well established time-resolved high-speed cinematography. Presently, extraction of devolatilization time-scales and temperature data at these time-scales running the high-speed films taken during the experiments employing a 16mm movie projector are in progress. Heat transfer analyses for the devolatilization time-scales, and temperature measurements (and hence an understanding of the effect of heating rates on coal thermal properties) are also in progress. Shipment of the donated heated grid system components from our industrial partner, United Technologies Research Center (UTRC), CT to CAU was complete during the previous reporting period. Testing of the heated grid system components at CAU and sensitivity analyses of the heated grid heat transfer calculations are also in progress.

Ramanathan Sampath

1999-04-29T23:59:59.000Z

97

Entirely passive heat-pipe apparatus capable of operating against gravity  

DOE Patents (OSTI)

The disclosure is directed to an entirely passive heat pipe apparatus capable of operating against gravity for vertical distances in the order of 3 to 7 and more. A return conduit into which an inert gas is introduced is used to lower the specific density of the working fluid so that it may be returned a greater vertical distance from condenser to evaporator.

Koenig, D.R.

1981-02-11T23:59:59.000Z

98

Understanding Utility Rates or How to Operate at the Lowest $/BTU  

E-Print Network (OSTI)

This paper is intended to give the reader knowledge into utility marketing strategies, rates, and services. Although water is a utility service, this paper will concern itself with the energy utilities, gas and electric. Commonality and diversity exist in the strategies and rates of the gas and electric utilities. Both provide services at no charge which make energy operation for their customers easier, safer and more economical. It is important to become familiar with utility strategies, rates, and services because energy knowledge helps your business operate at the lowest energy cost ($/BTU).

Phillips, J. N.

1993-03-01T23:59:59.000Z

99

Investigation of component failure rates for pulsed versus steady state tokamak operation  

Science Conference Proceedings (OSTI)

This report presents component failure rate data sources applicable to magnetic fusion systems, and defines multiplicative factors to adjust these data for specific use on magnetic fusion experiment designs. The multipliers address both long pulse and steady state tokamak operation. Thermal fatigue and radiation damage are among the leading reasons for large multiplier values in pulsed operation applications. Field failure rate values for graphite protective tiles are presented, and beryllium tile failure rates in laboratory testing are also given. All of these data can be used for reliability studies, safety analyses, design tradeoff studies, and risk assessments.

Cadwallader, L.C.

1992-07-01T23:59:59.000Z

100

Establishing low-power operating limits for liquid metal heat pipes  

SciTech Connect

Liquid metal heat pipes operated at power throughputs well below their design point for long durations may fail as a result of the working fluid migrating to a cold region within the pipe, freezing there, and hot returning to the evaporator section. Eventually sufficient working fluid inventory may be lost to the cold region to cause a local dry-out condition in the evaporator. A joint experimental and analytical effort between the Air Force Phillips Laboratory and Los Alamos National Laboratory is underway to investigate the phenomena. Experiments include both high temperature liquid metal and low temperature organic heat pipes. To date, a low temperature working fluid has been selected and its performance in a heat pipe validated. Additionally, a low-temperature heat pipe has been fabricated and is presently being tested.

Secary, J. (Phillips Lab., Kirtland AFB, NM (United States)); Merrigan, M.A.; Keddy, M.D. (Los Alamos National Lab., NM (United States))

1992-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "operating heat rate" 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

Establishing low-power operating limits for liquid metal heat pipes  

SciTech Connect

Liquid metal heat pipes operated at power throughputs well below their design point for long durations may fail as a result of the working fluid migrating to a cold region within the pipe, freezing there, and hot returning to the evaporator section. Eventually sufficient working fluid inventory may be lost to the cold region to cause a local dry-out condition in the evaporator. A joint experimental and analytical effort between the Air Force Phillips Laboratory and Los Alamos National Laboratory is underway to investigate the phenomena. Experiments include both high temperature liquid metal and low temperature organic heat pipes. To date, a low temperature working fluid has been selected and its performance in a heat pipe validated. Additionally, a low-temperature heat pipe has been fabricated and is presently being tested.

Secary, J. [Phillips Lab., Kirtland AFB, NM (United States); Merrigan, M.A.; Keddy, M.D. [Los Alamos National Lab., NM (United States)

1992-05-01T23:59:59.000Z

102

Elimination of Heat-Shielding for Geothermal Tools Operating Up To 300 Degress Celsius  

DOE Green Energy (OSTI)

This report focuses Sandia National Laboratories' effort to create high-temperature logging tools for geothermal applications not requiring heat-shielding. Tool electronics can operate up to 300 C with a few limiting components operating to 250 C. Second generation electronics are needed to increase measurement accuracy and extend the operating range to 300 and then 350 C are identified. Custom development of high-temperature batteries and assembling techniques are touched on. Outcomes of this work are discussed and new directions for developing high-temperature industry are suggested.

HENFLING,JOSEPH A.; NORMANN,RANDY A.

1999-10-07T23:59:59.000Z

103

SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer  

NLE Websites -- All DOE Office Websites (Extended Search)

High Operating Temperature Liquid Metal Heat Transfer Fluids High Operating Temperature Liquid Metal Heat Transfer Fluids UCLA logo University of California Berkeley logo Yale logo Four graphics in a grid that represent the sputtering technique being used in this project. Combinatorial screening and high throughput characterization of materials will be used to identify, develop, and demonstrate metal alloys that meet the MURI HOT Fluids targets suitable for CSP applications. The University of California, Los Angeles, the University of California, Berkeley, and Yale University The University of California, Los Angeles (UCLA), along with partners at the University of California, Berkeley, and Yale University, under the 2012 Multidisciplinary University Research Initiative (MURI): High Operating Temperature (HOT) Fluids funding opportunity, is investigating the use of metal alloys as a heat transfer fluid (HTF) in concentrating solar power (CSP) systems operating at temperatures in excess of 800°C. By allowing higher temperature operation, CSP systems can achieve greater efficiencies and thereby reduce the overall cost of electricity production.

104

EFFECT OF HEATING RATE ON THE THERMODYNAMIC PROPERTIES OF PULVERIZED COAL  

SciTech Connect

This semi-annual technical progress report describes work performed under DOE Grant No. DE-FG22-96PC96224 during the period March 24, 1998 to September 23, 1998 which covers the fourth six months of the project. Existing laser heating set-up at the Single Particle Laboratory, Federal Energy Technology Center, Morgantown, WV would work only in the range of 10 to 10 4 5 K/s. During this reporting period, appropriate changes were made to the laser heating system to heat particles in the range of 10 to 10 K/s. Also, calibration for all the components of the 4 7 electrodynamic balance measurement system including single-color pyrometer and heating laser was successfully completed. Following the calibration, a large number of single coal particles were caught in the electrodynamic balance and their volume, external surface area, mass, and density were measured. The same single particles were then heated bidirectionally with a pulsed (10 ms pulse width) Nd:YAG laser beams of equal intensity. The temporal power variation in the laser pulse was monitored for use in the heat transfer analysis by an ultra-fast fiber optic uv light transmitter included in the beam path and coupled to a silicon photodiode. Measurements of changes in particle size that accompanied rapid heating was made by means of the high-speed diode array imaging system discussed in our previous reports. Dynamics of volatile evolution and particle swelling were recorded using well established time-resolved high-speed cinematography. Measurements of the radiant emissive power from the heated and cooled (when the laser is turned off) particles was made using the single-color pyrometer. The above experiments are being repeated for a significant number of coal particles for a number of heating rates in between 10 - 10 K/s at FETC, Morgantown. 4 7 Shipment of the donated heated grid system components from our industrial partner, United Technologies Research Center (UTRC), CT to CAU was complete during this reporting period. Testing of the heated grid system components at CAU is also in progress.

RAMANATHAN SAMPATH

1998-10-27T23:59:59.000Z

105

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 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 modelbased 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. Key words: interplanetary medium – magnetohydrodynamics (MHD) – solar wind – Sun: corona – turbulence – waves Online-only material: tar file of source code 1.

Steven R. Cranmer

2010-01-01T23:59:59.000Z

106

Impacts of time-of-use rates on the optimal sizing and operation of cogeneration systems  

SciTech Connect

For customers with a cogeneration system (CGS), a mixed-integer programming and nonlinear programming model is used to examine effects of time-of-use (TOU) rates on the optimal operation of the constituent equipment as well as the optimal sizing. Three customers are selected for case studies: a hotel, a hospital, and an office building. Effects of an on-peak/off-peak energy charge ratio on purchased power share in the total electricity demand are saturated at the ratio of 5. As the energy charge ratio is raised, cheaper off-peak power substitutes for city gas and the operating cost decreases. The responses of the hotel and the hospital are similar. The simulation results included in this paper indicate that properly designed TOU rates can provide commercial customers an incentive to operate a CGS with an appropriate mix of the self-generation and commercial power.

Asano, H.; Sagai, S.; Imamura, E. (Central Research Inst. of Electric Power Industry, Tokyo (Japan)); Ito, K.; Yokoyama, R. (Osaka Prefectural Univ., Sakai (Japan))

1992-11-01T23:59:59.000Z

107

Energy savings from operation and maintenance training for apartment boiler heating systems  

SciTech Connect

The Portland Energy Office provided operation and maintenance (O M) training to the operators of boiler heating systems for ten low-income apartment complexes in the Fall of 1990. This study tracked energy usage before and after O M training to see if savings occurred. Training was provided on both weatherized and non-weatherized apartments to find out if weatherization impacted the amount of O M savings to be obtained. Also, energy savings from the O M training and building shell weatherization are compared. The O M training averaged about four hours per building. Content was adjusted at each site to match needs of the boiler and operator. The Energy Office also provided a boiler tune-up by a service technician. The training stressed low-cost and no-cost measures which operators could either do themselves or hire service help to implement. It also emphasized boiler safety. Nine of the ten apartment complexes in the study used less energy per heating degree-day after the O M help. Average savings were 10%. Four apartments chosen randomly as controls had negative savings; they used slightly more energy during the same post-O M time frame. Weatherized and unweatherized apartments showed similar savings after the O M help, 10% and 11% percent respectively. Savings from weatherization of six of the apartments in the winter of 1988--1989 were also measured. A low average of only 4% was observed, reflecting negative savings in two buildings.

1992-02-01T23:59:59.000Z

108

Residential and commercial space heating and cooling with possible greenhouse operation; Baca Grande development, San Luis Valley, Colorado. Final report  

DOE Green Energy (OSTI)

A feasibility study was performed to evaluate the potential of multipurpose applications of moderate-temperature geothermal waters in the vicinity of the Baca Grande community development in the San Luis Valley, Colorado. The project resource assessment, based on a thorough review of existing data, indicates that a substantial resource likely exists in the Baca Grande region capable of supporting residential and light industrial activity. Engineering designs were developed for geothermal district heating systems for space heating and domestic hot water heating for residences, including a mobile home park, an existing motel, a greenhouse complex, and other small commercial uses such as aquaculture. In addition, a thorough institutional analysis of the study area was performed to highlight factors which might pose barriers to the ultimate commercial development of the resource. Finally, an environmental evaluation of the possible impacts of the proposed action was also performed. The feasibility evaluation indicates the economics of the residential areas are dependent on the continued rate of housing construction. If essentially complete development could occur over a 30-year period, the economics are favorable as compared to existing alternatives. For the commercial area, the economics are good as compared to existing conventional energy sources. This is especially true as related to proposed greenhouse operations. The institutional and environmental analyses indicates that no significant barriers to development are apparent.

Goering, S.W.; Garing, K.L.; Coury, G.E.; Fritzler, E.A.

1980-05-01T23:59:59.000Z

109

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.

Dubessy, Romain; Guidoni, Luca

2008-01-01T23:59:59.000Z

110

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

111

Sensitivity of shortwave radiative flux density, forcing, and heating rates to the aerosol vertical profile  

SciTech Connect

The effect of the aerosol vertical distribution on the solar radiation profiles, for idealized and measured profiles of optical properties (extinction and single-scattering albedo (SSA)) during the May 2003 Atmospheric Radiation Measurement (ARM) Aerosol Intensive Observation Period (AIOP), has been investigated using the Rapid Radiative Transfer Model Shortwave (RRTM_SW) code. Calculated profiles of down-welling and up-welling solar fluxes during the AIOP have been compared with the data measured by up- and down-looking solar broadband radiometers aboard a profiling research aircraft. The measured profiles of aerosol extinction, SSA, and water vapor obtained from the same aircraft that carried the radiometers served as the inputs for the model calculations. It is noteworthy that for this study, the uplooking radiometers were mounted on a stabilized platform that kept the radiometers parallel with respect to the earth’s horizontal plane. The results indicate that the shape of the aerosol extinction profiles has very little impact on direct radiative forcings at the top of atmosphere and surface in a cloud-free sky. However, as long as the aerosol is not purely scattering, the shape of the extinction profiles is important for forcing profiles. Identical extinction profiles with different absorption profiles drastically influence the forcing and heating rate profiles. Using aircraft data from 19 AIOP profiles over the Southern Great Plains (SGP), we are able to achieve broadband down-welling solar flux closure within 0.8% (bias difference) or 1.8% (rms difference), well within the expected measurement uncertainty of 1 to 3%. The poorer agreement in up-welling flux (bias -3.7%, rms 10%) is attributed to the use of inaccurate surface albedo data. The sensitivity tests reveal the important role accurate, vertically resolved aerosol extinction data plays in tightening flux closure. This study also suggests that in the presence of a strongly absorbing substance, aircraft flux measurements from a stabilized platform have the potential to determine heating rate profiles. These measurement-based heating rate profiles provide useful data for heating rate closure studies and indirect estimates of single scattering albedo assumed in radiative transfer calculations.

Guan, Hong; Schmid, Beat; Bucholtz, Anthony; Bergstrom, Robert

2010-03-31T23:59:59.000Z

112

Comments on the use of boiler efficiencies to determine unit heat rate  

SciTech Connect

The expression for boiler efficiency defined in ASME PTC4.1 was developed for evaluating boiler performance, carrying out acceptance tests on boilers and computing the effects of changes in parameters such as fuel characteristics on boiler performance. While satisfactory for applications such as these, this particular definition of boiler efficiency can result in substantial errors when used for computing unit performance. Sample calculations are presented for a 600 MW coal fired unit which show errors in net unit heat rate of 1 to 3 percent due to inconsistent definitions for boiler efficiency.

Levy, E.K.; Sarunac, N. (Lehigh Univ., Bethlehem, PA (USA). Energy Research Center); Leyse, R. (Electric Power Research Inst., Palo Alto, CA (USA))

1990-01-01T23:59:59.000Z

113

Guide to Combined Heat and Power Systems for Boiler Owners and Operators  

Science Conference Proceedings (OSTI)

Combined heat and power (CHP) or cogeneration is the sequential production of two forms of useful energy from a single fuel source. In most CHP applications, chemical energy in fuel is converted to both mechanical and thermal energy. The mechanical energy is generally used to generate electricity, while the thermal energy or heat is used to produce steam, hot water, or hot air. Depending on the application, CHP is referred to by various names including Building Cooling, Heating, and Power (BCHP); Cooling, Heating, and Power for Buildings (CHPB); Combined Cooling, Heating, and Power (CCHP); Integrated Energy Systems (IES), or Distributed Energy Resources (DER). The principal technical advantage of a CHP system is its ability to extract more useful energy from fuel compared to traditional energy systems such as conventional power plants that only generate electricity and industrial boiler systems that only produce steam or hot water for process applications. By using fuel energy for both power and heat production, CHP systems can be very energy efficient and have the potential to produce electricity below the price charged by the local power provider. Another important incentive for applying cogeneration technology is to reduce or eliminate dependency on the electrical grid. For some industrial processes, the consequences of losing power for even a short period of time are unacceptable. The primary objective of the guide is to present information needed to evaluate the viability of cogeneration for new or existing industrial, commercial, and institutional (ICI) boiler installations and to make informed CHP equipment selection decisions. Information presented is meant to help boiler owners and operators understand the potential benefits derived from implementing a CHP project and recognize opportunities for successful application of cogeneration technology. Topics covered in the guide follow: (1) an overview of cogeneration technology with discussions about benefits of applying cogeneration technology and barriers to implementing cogeneration technology; (2) applicable federal regulations and permitting issues; (3) descriptions of prime movers commonly used in CHP applications, including discussions about design characteristics, heat-recovery options and equipment, fuels and emissions, efficiency, maintenance, availability, and capital cost; (4) electrical generators and electrical interconnection equipment; (5) cooling and dehumidification equipment; (6) thermodynamic cycle options and configurations; (7) steps for evaluating the technical and economic feasibility of applying cogeneration technology; and (8) information sources.

Oland, CB

2004-08-19T23:59:59.000Z

114

On-Line Heat Rate Monitor Assessment, Part 2: Results of the Demonstration and Application of Exergetic Systems' Calculational Engine  

Science Conference Proceedings (OSTI)

This report summarizes EPRI demonstrations of Exergetic Systems' Calculational Engine, an on-line heat rate monitor, at two pulverized-coal-fired plants. It also summarizes results from independent installations and tests of the Calculational Engine.

2004-12-27T23:59:59.000Z

115

Latent Heating and Cooling Rates in Developing and Nondeveloping Tropical Disturbances during TCS-08: TRMM PR versus ELDORA Retrievals  

Science Conference Proceedings (OSTI)

Unique sets of Electra Doppler Radar (ELDORA) observations in both developing and nondeveloping tropical disturbances in the western North Pacific are used to retrieve latent heating and cooling rates. During the reintensification of Sinlaku, ...

Myung-Sook Park; Russell L. Elsberry

2013-01-01T23:59:59.000Z

116

A Comparative Analysis of Upper-Ocean Heat Content Variability from an Ensemble of Operational Ocean Reanalyses  

Science Conference Proceedings (OSTI)

Ocean heat content (HC) is one of the key indicators of climate variability and also provides ocean memory critical for seasonal and decadal predictions. The availability of multiple operational ocean analyses (ORAs) now routinely produced around ...

Yan Xue; Magdalena A. Balmaseda; Tim Boyer; Nicolas Ferry; Simon Good; Ichiro Ishikawa; Arun Kumar; Michele Rienecker; Anthony J. Rosati; Yonghong Yin

2012-10-01T23:59:59.000Z

117

Burnup increase and Power Up-rate - Operation history of KKL  

Science Conference Proceedings (OSTI)

The Leibstadt nuclear power plant in Switzerland? (KKL), a GE BWR/6 boiling water reactor with an up-rated thermal power of 3600 MW and a nominal net electrical output of 1145 W has been operated for more than 20 years. The core today consists of 648 modern 10x10 assemblies with part length rods which results in a power density of 32 kW/kg Uranium or 63 kW/dm{sup 3}. The plant is operated in a 12 month cycle with shut downs in August. During the last 15 years the transformation of the core was carefully monitored and different fuel assemblies and control rods have been evaluated for an optimized performance of the core. Experience has been gained on core design with control cell core operation and a number of operational issues like change of the isothermal temperature coefficient (ITC), water chemistry with zinc addition and operation with failed fuel. The fuel and fuel assembly behavior has been monitored with numerous fuel inspections on lead use assemblies and selected reload batch assemblies. They have established a good understanding of an optimal fuel performance up to high burnup and the inspection techniques applied in the spent fuel pool on site normally during the outage. (authors)

Ledergerber, G.; Kaufmann, W.; Ritter, A.; Greiner, D. [Kernkraftwerk Leibstadt AG, CH-5325 Leibstadt (Switzerland); Parmar, Y.; Jacot-Guillarmod, R.; Krouthen, J. [Nordostschweizerische Kraftwerke AG, CH-5400 Baden (Switzerland)

2007-07-01T23:59:59.000Z

118

Evaluation of the heating operation and transmission district: Feasibility of cogeneration. Final report  

Science Conference Proceedings (OSTI)

The General Services Administration, through its National Capital Region, operates a district heating system - called the Heating Operation and Transmission District - that provides steam to approximately 100 government buildings in Washington, D.C. HOTD is examining a host of options that will improve its ability to provide reliable, environmentally sound, and cost-effective service to its customers. This report evaluates one of those options - cogeneration, a technology that would enable HOTD to produce steam and electricity simultaneously. The study concluded that, under current regulations, cogeneration is not attractive economically because the payback period (15 years) exceeds Federal return-on-investment guidelines. However, if the regulatory environment changes to allow wheeling (transmission of power by a non-utility power producer to another user), cogeneration would be attractive; HOTD would save anywhere from $38 million to $118 million and the investment would pay back in 7 to 10 years. Although incorporating cogeneration into the HOTD system has no strong benefit at this time, the report recommends that GSA reevaluate cogeneration in one or two years because Federal regulations regarding wheeling are under review. It also recommends that GSA work with the District of Columbia government to develop standards for cogeneration.

Cable, J.H.; Gilday, L.T.; Moss, M.E.

1995-11-01T23:59:59.000Z

119

Latent Heating and Cooling Rates in Developing and Nondeveloping Tropical Disturbances during TCS-08: Radar-Equivalent Retrievals from Mesoscale Numerical Models and ELDORA  

Science Conference Proceedings (OSTI)

Latent heating and cooling rates have a critical role in predicting tropical cyclone formation and intensification. In a prior study, Park and Elsberry estimated the latent heating and cooling rates from aircraft Doppler radar [Electra Doppler ...

Myung-Sook Park; Andrew B. Penny; Russell L. Elsberry; Brian J. Billings; James D. Doyle

2013-01-01T23:59:59.000Z

120

Influence of Mean Zonal Motion and Meridional Temperature Gradients on the Solar Semidiurnal Atmospheric Tide: A Revised Spectral Study with Improved Heating Rates  

Science Conference Proceedings (OSTI)

Calculations of the semidiurnal atmospheric tide at solstice using improved heating rates are presented. The heating rates for solar absorption by water vapor are based on a global water vapor distribution (Jenne, 1969, 1975; Jenne et al., 1974), ...

R. L. Walterscheid; J. G. DeVore; S. V. Venkateswaran

1980-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "operating heat rate" 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
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121

Real-Time Combined Heat and Power Operational Strategy Using a Hierarchical Optimization Algorithm  

Science Conference Proceedings (OSTI)

Existing attempts to optimize the operation of Combined Heat and Power (CHP) systems for building applications have two major limitations: the electrical and thermal loads are obtained from historical weather profiles; and the CHP system models ignore transient responses by using constant equipment efficiencies. This paper considers the transient response of a building combined with a hierarchical CHP optimal control algorithm to obtain a real-time integrated system that uses the most recent weather and electric load information. This is accomplished by running concurrent simulations of two transient building models. The first transient building model uses current as well as forecast input information to obtain short term predictions of the thermal and electric building loads. The predictions are then used by an optimization algorithm, i.e., a hierarchical controller, that decides the amount of fuel and of electrical energy to be allocated at the current time step. In a simulation, the actual physical building is not available and, hence, to simulate a real-time environment, a second, building model with similar but not identical input loads are used to represent the actual building. A state-variable feedback loop is completed at the beginning of each time step by copying, i.e., measuring, the state variable from the actual building and restarting the predictive model using these ?measured? values as initial conditions. The simulation environment presented in this paper features nonlinear effects such as the dependence of the heat exchanger effectiveness on their operating conditions. The results indicate that the CHP engine operation dictated by the proposed hierarchical controller with uncertain weather conditions have the potential to yield significant savings when compared to conventional systems using current values of electricity and fuel prices.

Yun, Kyung Tae; Cho, Heejin; Luck, Rogelio; Mago, Pedro J.

2011-06-01T23:59:59.000Z

122

Operator renewal theory and mixing rates for dynamical systems with infinite measure  

E-Print Network (OSTI)

We develop a theory of operator renewal sequences in the context of infinite ergodic theory. For large classes of dynamical systems preserving an infinite measure, we determine the asymptotic behaviour of iterates $L^n$ of the transfer operator. This was previously an intractable problem. Examples of systems covered by our results include (i) parabolic rational maps of the complex plane and (ii) (not necessarily Markovian) nonuniformly expanding interval maps with indifferent fixed points. In addition, we give a particularly simple proof of pointwise dual ergodicity (asymptotic behaviour of $\\sum_{j=1}^nL^j$) for the class of systems under consideration. In certain situations, including Pomeau-Manneville intermittency maps, we obtain higher order expansions for $L^n$ and rates of mixing. Also, we obtain error estimates in the associated Dynkin-Lamperti arcsine laws.

Melbourne, Ian

2010-01-01T23:59:59.000Z

123

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

NLE Websites -- All DOE Office Websites (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

124

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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,

125

Optimizing the operation of an urban district heating system by means of variable speed drives  

Science Conference Proceedings (OSTI)

In this work is presenting an urban district heating system which is subjected to a modernization process. The urban district heating system is composed by the pumping station of the primary heat carrier and the district heating stations. The modernization ... Keywords: district heating system, energetic efficiency, pumping station, static frequency converter, testing

Sorin Ioan Deaconu; Gabriel Nicolae Popa; Iosif Popa

2008-07-01T23:59:59.000Z

126

Design and technology of heat pipes for cooling and heat exchange  

SciTech Connect

This new book presents a comprehensive account of heat pipe design, technology, and operation. It is based on insights and techniques developed by the author during more than twenty years of investigating high-performance heat pipe systems. The book provides information on a unique device with the capability to transport heat isothermally at high rates with no external power input. Emphasis is on high-performance liquid metal heat pipes, although nonliquid metal heat pipes are treated, as well. The first three chapters deal with the nonmathematical background for understanding heat pipe operation and heat transport capability. Remaining chapters detail heat pipe characteristics and design methods. Of special interest are simplified equations for obtaining heat pipe heat transport limits, heat pipe heat exchangers, heat pipe transient behavior, and inverted (nonwetting) heat pipes. Operational boundaries on heat pipe temperature and heat transport rate are described, and step-by-step procedures are given for involved calculations.

Silverstein, C.C.

1992-01-01T23:59:59.000Z

127

Proof of Operation in a Planar Loop Heat Pipe (LHP) Based on CPS Wick.  

E-Print Network (OSTI)

??As electronic design allows higher throughput in small packages, dissipating the heat load becomes a critical design factor. Available cooling approaches, such as extruded heat… (more)

Suh, Junwoo

2005-01-01T23:59:59.000Z

128

Crack growth rates of irradiated austenitic stainless steel weld heat affected zone in BWR environments.  

Science Conference Proceedings (OSTI)

Austenitic stainless steels (SSs) are used extensively as structural alloys in the internal components of reactor pressure vessels because of their superior fracture toughness. However, exposure to high levels of neutron irradiation for extended periods can exacerbate the corrosion fatigue and stress corrosion cracking (SCC) behavior of these steels by affecting the material microchemistry, material microstructure, and water chemistry. Experimental data are presented on crack growth rates of the heat affected zone (HAZ) in Types 304L and 304 SS weld specimens before and after they were irradiated to a fluence of 5.0 x 10{sup 20} n/cm{sup 2} (E > 1 MeV) ({approx} 0.75 dpa) at {approx}288 C. Crack growth tests were conducted under cycling loading and long hold time trapezoidal loading in simulated boiling water reactor environments on Type 304L SS HAZ of the H5 weld from the Grand Gulf reactor core shroud and on Type 304 SS HAZ of a laboratory-prepared weld. The effects of material composition, irradiation, and water chemistry on growth rates are discussed.

Chopra, O. K.; Alexandreanu, B.; Gruber, E. E.; Daum, R. S.; Shack, W. J.; Energy Technology

2006-01-31T23:59:59.000Z

129

Preliminary operational results of the low-temperature solar industrial process heat field tests  

DOE Green Energy (OSTI)

Six solar industrial process heat field tests have been in operation for a year or more - three are hot water systems and three are hot air systems. All are low-temperature projects (process heat at temperatures below 212/sup 0/F). Performance results gathered by each contractor's data acquisition system are presented and project costs and problems encountered are summarized. Flat-plate, evacuated-tube, and line-focus collectors are all represented in the program, with collector array areas ranging from 2500 to 21,000 ft/sup 2/. Collector array efficiencies ranged from 12% to 36% with net system efficiencies from 8% to 33%. Low efficiencies are attributable in some cases to high thermal losses and, for the two projects using air collectors, are due in part to high parasitic power consumption. Problems have included industrial effluents on collectors, glazing and absorber surface failures, excessive thermal losses, freezing and overheating, control problems, and data acquisition system failure. With design and data acquisition costs excluded costs of the projects ranged from $25/ft/sup 2/ to $87/ft/sup 2/ and $499/(MBtu/yr) to $1537/(MBtu/yr).

Kutscher, C.F.; Davenport, R.L.

1980-06-01T23:59:59.000Z

130

Army Solid State Laser Program: Design, Operation, and Mission Analysis for a Heat-Capacity Laser  

DOE Green Energy (OSTI)

Solid-state lasers have held great promise for the generation of high-average-power, high-quality output beams for a number of decades. However, the inherent difficulty of scaling the active solid-state gain media while continuing to provide efficient cooling has limited demonstrated powers to <5kW. Even at the maximum demonstrated average powers, the output is most often delivered as continuous wave (CW) or as small energy pulses at high pulse repetition frequency (PRF) and the beam divergence is typically >10X the diffraction limit. Challenges posed by optical distortions and depolarization arising from internal temperature gradients in the gain medium of a continuously cooled system are only increased for laser designs that would attempt to deliver the high average power in the form of high energy pulses (>25J) from a single coherent optical aperture. Although demonstrated phase-locking of multiple laser apertures may hold significant promise for the future scaling of solid-state laser systems,1 the continuing need for additional technical development and innovation coupled with the anticipated complexity of these systems effectively limits this approach for near-term multi-kW laser operation outside of a laboratory setting. We have developed and demonstrated a new operational mode for solid-state laser systems in which the cooling of the gain medium is separated in time from the lasing cycle. In ''heat-capacity'' operation, no cooling takes place during lasing. The gain medium is pumped very uniformly and the waste heat from the excitation process is stored in the solid-state gain medium. By depositing the heat on time scales that are short compared to thermal diffusion across the optical aperture, very high average power operation is possible while maintaining low optical distortions. After a lasing cycle, aggressive cooling can then take place in the absence of lasing, limited only by the fracture limit of the solid-state medium. This mode of operation is ideally suited for applications that require 1-30s engagements at very high average power. If necessary, multiple laser apertures can provide continuous operation. Land Combat mission analysis of a stressing air defense scenario including a dense attack of rockets, mortars, and artillery has indicated that multiple HEL weapon systems, based on the solid state, heat capacity laser concept, can provide significantly improved protection of high value battlefield assets. We will present EADSIM results for two government-supplied scenarios, one with temporally high threat density over a fairly large defended area, and one with fewer threats concentrating on a single defended asset. Implications for weapon system requirements will be presented. In order to demonstrate the operation of a high average power heat-capacity laser system, we have developed a flashlamp-pumped Nd:glass laser with output energies in the range of 500-1000J/pulse in a 10 x 10cm{sup 2} beam. With a repetition frequency of 20Hz, an average power of 13kW has been demonstrated for operational periods of up to 10s using a stable optical resonator (see enclosed figure). Using an M=1.4 unstable resonator, a beam divergence of 5X diffraction-limited has been measured with no active wavefront correction. An adaptively corrected unstable resonator that incorporates an intracavity deformable mirror controlled by feedback from an external wavefront sensor will provide <2X diffraction-limited output integrated over an entire 10s run at an average power of 10kW. A very similar laser architecture in which the Nd:glass is replaced by Nd:GGG and the flashlamps are replaced by large diode-laser arrays will enable the scaling of the output average power from the demonstrated 10kW to 100kW (500J/pulse at 200Hz). Risk reduction experiments for diode-pumped Nd:GGG, the fabrication of large Nd:GGG amplifier slabs, as well as the progress toward a sub-scale amplifier testbed pumped by diode arrays with total of 1MW peak power will also be presented.

Dane, C B; Flath, L; Rotter, M; Fochs, S; Brase, J; Bretney, K

2001-05-18T23:59:59.000Z

131

Coal plasticity at high heating rates and temperatures. First technical progress report for the fourth quarter 1989  

SciTech Connect

The broad objective of this project is to obtain improved, quantitative understanding of the transient plasticity of bituminous coals under high heating rates and other reaction and pretreatment conditions of scientific and practical interest. To these ends the research plan is to measure the softening and resolidification behavior of two US bituminous coals with a rapid-heating, fast response, high-temperature coal plastometer, previously developed in this laboratory. Specific measurements planned for the project include determinations of apparent viscosity, softening temperature, plastic period, and resolidificationtime for molten coal: (1) as a function of independent variations in coal type, heating rate, final temperature, gaseous atmosphere (inert, 0{sub 2} or H{sub 2}), and shear rate; and (2) in exploratory runs where coal is pretreated (preoxidation, pyridine extraction, metaplast cracking agents), before heating. The intra-coal inventory and molecular weight distribution of pyridine extractables will also be measured using a rapid quenching, electrical screen heater coal pyrolysis reactor. The yield of extractables is representative of the intra-coal inventory of plasticing agent (metaplast) remaining after quenching. Coal plasticity kinetics will then be mathematically modeled from metaplast generation and depletion rates, via a correlation between the viscosity of a suspension and the concentration of deformable medium (here metaplast) in that suspension. Work during this reporting period has been concerned with re-commissioning the rapid heating rate plastometer apparatus.

Darivakis, G.S.; Peters, W.A.; Howard, J.B.

1990-01-01T23:59:59.000Z

132

Modeling and Experimental Research on Ground-Source Heat Pump in Operation by Neural Network  

Science Conference Proceedings (OSTI)

Ground source Heat Pump(GSHP) is becoming the more and more focus of the world¡¯s attention as a HVAC technique of energy saving and environment protection. This paper first introduced the experiment for Ground-Source water/water Heat Pump. The heat ... Keywords: Ground-Source Heat Pump(GSHP), Neural Network(NN) Predication modeling

Jianping Chen; Zhiwei Lian; Lizheng Tan; Weifeng Zhu; Weiqiang Zhang

2011-02-01T23:59:59.000Z

133

Heat transfer rates for filmwise, dropwise, and superhydrophobic condensation on silicon substrates  

E-Print Network (OSTI)

Condensation, a two-phase heat transfer processes, is commonly utilized in industrial systems. Condensation heat transfer can be optimized by using surfaces in which dropwise condensation (DWC) occurs, and even further ...

Hery, Travis M

2011-01-01T23:59:59.000Z

134

Characterizing (rating) the performance of large photovoltaic arrays for all operating conditions  

DOE Green Energy (OSTI)

A new method has been developed for characterizing the electrical performance of photovoltaic arrays. The method provides both a ``rating`` at standard reporting conditions and a rigorous yet straightforward model for predicting array performance at all operating conditions. For the first time, the performance model handles the influences of irradiance, module temperature, solar spectrum, solar angle-of-incidence, and temperature coefficients, in a practical way. Validity of the procedure was confirmed during field testing of a 25-kW array recently installed by Arizona Public Service Co. on Carol Spring Mountain (which powers microwave, ceullular phone, and TV communictions equipment). This paper describes the characterization procedure, measured array performance, and the predictive model.

King, D.L. [Sandia National Labs., Albuquerque, NM (United States); Eckert, P.E. [Arizona Public Service Co., Phoenix, AZ (United States)

1996-06-01T23:59:59.000Z

135

Influence of Transfer Efficiency of the Outdoor Pipe Network and Boiler Operating Efficiency on the Building Heat Consumption Index  

E-Print Network (OSTI)

This paper analyzes the influence of transfer efficiency of the outdoor pipe network and operating efficiency of the boiler on the building heat consumption index, on the premise of saving up to 65 percent energy in different climates. The results show that transfer efficiency is not influenced by the climate, and the influence is in accordance with that in other climates. The article also presents data on the energy consumption caused by the improvement of the transfer efficiency of the outdoor pipe network and the operating efficiency of the boiler, and the calculated formula for the building heat consumption index on the condition of saving 65 percent energy.

Fang, X.; Wang, Z.; Liu, H.

2006-01-01T23:59:59.000Z

136

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

SciTech Connect

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.

Hoeschele, M.; Weitzel, E.

2013-05-01T23:59:59.000Z

137

MEASURED AND CALCULATED HEATING AND DOSE RATES FOR THE HFIR HB4 BEAM TUBE AND COLD SOURCE  

SciTech Connect

The High Flux Isotope Reactor at the Oak Ridge National Laboratory was upgraded to install a cold source in horizontal beam tube number 4. Calculations were performed and measurements were made to determine heating within the cold source and dose rates within and outside a shield tunnel surrounding the beam tube. This report briefly describes the calculations and presents comparisons of the measured and calculated results. Some calculated dose rates are in fair to good agreement with the measured results while others, particularly those at the shield interfaces, differ greatly from the measured results. Calculated neutron exposure to the Teflon seals in the hydrogen transfer line is about one fourth of the measured value, underpredicting the lifetime by a factor of four. The calculated cold source heating is in good agreement with the measured heating.

Slater, Charles O [ORNL; Primm, Trent [ORNL; Pinkston, Daniel [ORNL; Cook, David Howard [ORNL; Selby, Douglas L [ORNL; Ferguson, Phillip D [ORNL; Bucholz, James A [ORNL; Popov, Emilian L [ORNL

2009-03-01T23:59:59.000Z

138

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

Science Conference Proceedings (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

139

Induction Heating Stress Improvement Effectiveness on Crack Growth in Operating Plants (BWRVIP-61)  

Science Conference Proceedings (OSTI)

New reports of intergranular stress corrosion cracking prompted this review of factors that could influence the performance of the pipe cracking remedy known as induction heating stress improvement.

1999-01-27T23:59:59.000Z

140

Operational and maintenance instruction manual for the Ingham County Geriatric Medical Care Facility solar water-heating system  

DOE Green Energy (OSTI)

The Ingham County solar system consists of approximately 10,000 square feet of solar collectors connected in a closed configuration loop. The primary loop solution is a 1:12 mixture of water and propylene glycol which flows through the tube side of a heat exchanger connected to the primary storage tank. The heat energy which is supplied to the primary storage tank is subsequently used to preheat the temperature of the laundry water, kitchen water, and domestic potable water. Included in this report are: detailed drawings and flow chart; operational methodology; preventive maintenance instructions; general instructions and safety precautions; and a corrective maintenance and tabulation of failure modes. Appendices include: manufacturers technical manual and component specifications; IBM data sensors and responsibilities; digital county monitor operations manual; and on site monitor operations manual. Reference CAPE-2834. (LS)

Not Available

1983-07-29T23:59:59.000Z

Note: This page contains sample records for the topic "operating heat rate" 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

Heating Rate within the Upper Ocean in Relation to its Bio–optical State  

Science Conference Proceedings (OSTI)

Solar radiation absorption and local heating within the upper layers of the open ocean are strongly influenced by the abundance of phytoplankton as depicted by the chlorophyll concentration. According to whether this concentration is high or low, ...

André Morel; David Antoine

1994-07-01T23:59:59.000Z

142

RATES  

NLE Websites -- All DOE Office Websites (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)

143

RATES  

NLE Websites -- All DOE Office Websites (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

144

Rod Bundle Heat Transfer for Pressurized Water Reactors at Operating Conditions  

Science Conference Proceedings (OSTI)

Currently available heat transfer correlations for subcooled forced convection and subcooled boiling have not been validated with rod-array data at typical PWR fluid conditions. At the present time, rod bundle heat transfer processes cannot be analyzed with sufficient accuracy to make sound decisions regarding changes that might avoid an Axial Offset Anomaly (AOA).

2000-07-14T23:59:59.000Z

145

RATES  

NLE Websites -- All DOE Office Websites (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)

146

Comparison between a spray column and a sieve tray column operating as liquid-liquid heat exchangers  

DOE Green Energy (OSTI)

The performance of a spray column and a sieve tray column was compared as a liquid-liquid heat exchanger. In carrying out these studies a 15.2 cm (6.0 in.) diameter column, 183 cm (6.0 ft) tall was utilized. The performance of the spray column as a heat exchanger was shown to correlate with the model of Letan-Kehat which has as a basis that the heat transfer is dominated by the wakeshedding characteristics of the drops over much of the column length. This model defines several hydrodynamic zones along the column of which the wake formation zone at the bottom appears to have the most efficient heat transfer. The column was also operated with four perforated plates spaced two column diameters apart in order to take advantage of the wake formation zone heat transfer. The plates induce coalescence of the dispersed phase and reformation of the drops, and thus cause a repetition of the wake formation zone. It is shown that the overall volumetric heat transfer coefficient in a perforated plate column is increased by a minimum of eleven percent over that in a spray column. A hydrodynamic model that predicts the performance of a perforated plate column is suggested.

Keller, A.; Jacobs, H.R.; Boehm, R.F.

1980-12-01T23:59:59.000Z

147

MODEL FOR ALFVEN WAVE TURBULENCE IN SOLAR CORONAL LOOPS: HEATING RATE PROFILES AND TEMPERATURE FLUCTUATIONS  

Science Conference Proceedings (OSTI)

It has been suggested that the solar corona may be heated by dissipation of Alfven waves that propagate up from the solar photosphere. According to this theory, counterpropagating Alfven waves are subject to nonlinear interactions that lead to turbulent decay of the waves and heating of the chromospheric and coronal plasma. To test this theory, better models for the dynamics of Alfven waves in coronal loops are required. In this paper, we consider wave heating in an active region observed with the Solar Dynamics Observatory in 2010 May. First a three-dimensional (3D) magnetic model of the region is constructed, and ten magnetic field lines that match observed coronal loops are selected. For each loop we construct a 3D magnetohydrodynamic model of the Alfven waves near the selected field line. The waves are assumed to be generated by footpoint motions inside the kilogauss magnetic flux elements at the two ends of the loop. Based on such models, we predict the spatial and temporal profiles of the heating along the selected loops. We also estimate the temperature fluctuations resulting from such heating. We find that the Alfven wave turbulence model can reproduce the observed characteristics of the hotter loops in the active region core, but the loops at the periphery of the region have large expansion factors and are predicted to be thermally unstable.

Asgari-Targhi, M.; Van Ballegooijen, A. A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street MS-15, Cambridge, MA 02138 (United States)

2012-02-10T23:59:59.000Z

148

Measured Performance and Analysis of Ground Source Heat Pumps for Space Conditioning and for Water Heating in a Low-Energy Test House Operated under Simulated Occupancy Conditions  

Science Conference Proceedings (OSTI)

In this paper we present measured performance and efficiency metrics of Ground Source Heat Pumps (GSHPs) for space conditioning and for water heating connected to a horizontal ground heat exchanger (GHX) loop. The units were installed in a 345m2 (3700ft2) high-efficiency test house built with structural insulated panels (SIPs), operated under simulated occupancy conditions, and located in Oak Ridge, Tennessee (USA) in US Climate Zone 4 . The paper describes distinctive features of the building envelope, ground loop, and equipment, and provides detailed monthly performance of the GSHP system. Space conditioning needs of the house were completely satisfied by a nominal 2-ton (7.0 kW) water-to-air GSHP (WA-GSHP) unit with almost no auxiliary heat usage. Recommendations for further improvement through engineering design changes are identified. The comprehensive set of data and analyses demonstrate the feasibility and practicality of GSHPs in residential applications and their potential to help achieve source energy and greenhouse gas emission reduction targets set under the IECC 2012 Standard.

Ally, Moonis Raza [ORNL; Munk, Jeffrey D [ORNL; Baxter, Van D [ORNL; Gehl, Anthony C [ORNL

2012-01-01T23:59:59.000Z

149

A Test of a Lapse Rate/Wind Speed Model for Estimating Heat Island Magnitude in an Urban Airshed  

Science Conference Proceedings (OSTI)

In the winter of 1975/76 a helicopter was used to obtain temperature profiles across the city of Calgary. This operation was supported by airborne measurements of wind speed and lapse rate at the edge of the city, upwind. Regression analysis ...

Lawrence C. Nkemdirim

1980-06-01T23:59:59.000Z

150

Heat Recovery Steam Generators for Combined Cycle Applications: HRSG Procurement, Design, Construction, and Operation Update  

Science Conference Proceedings (OSTI)

Design alternatives and procurement approaches for heat recovery steam generators, supplemental firing duct burners, and ancillary steam systems are addressed in this report. Power engineers and project developers will find an up-to-date, comprehensive resource for planning, specification and preliminary design in support of combined cycle plant development.

2005-03-29T23:59:59.000Z

151

Operator splitting approach applied to oscillatory flow and heat transfer in a tube  

Science Conference Proceedings (OSTI)

The method of operator splitting is applied to an advection-diffusion model as it occurs in a pulse tube. Firstly, the governing equations of the simplified model are studied and the mathematical description is derived. Then the splitting approach is ... Keywords: 35L65, 65M06, 80A20, Domain decomposition, Operator splitting, Pulse tube, Recuperator, Taylor dispersion

R. Widura; M. Lehn; K. Muralidhar; R. Scherer

2008-02-01T23:59:59.000Z

152

Evaluation and Analysis of an Integrated PEM Fuel Cell with Absorption Cooling and Water Heating System for Sustainable Building Operation  

E-Print Network (OSTI)

In this paper, a parametric study of a PEM fuel cell integrated with a double effect absorption system is carried out in order to study the effect of different operating conditions on the efficiency of the PEM fuel cell, utilization factor of the over all system, COPs of the double effect cooling and heating system, and power and heat output of the PEM fuel cell. It is found that the efficiency of the cell decreases, ranging from 46.2% to 24.4% with increase in membrane thickness and current density, and at the same time the COP increases ranging from 0.65 to 1.52. The heat and power output of the fuel cell decreases from 10.54 kW to 5.12 kW, and 9.12 kW to 6.99 kW, respectively for the increase in membrane thickness. However, when the temperature of the cell is increased the heat and power output increases from 5.12 kW to 10.54 kW, and 6.9 kW to 7.02 kW, respectively. The COP is found to be decreasing ranging from 1.53 to 0.33 with the increase in temperature of the cell and heat input to the HTG. As for the utilization factor, it increases ranging from 17% to 87% with increase in the temperature of the cell and heat input to the HTG. This study reveals that an integrated PEM fuel cell with a double effect absorption cooling systems has a very high potential to be an economical and environmental solution as compared with conventional systems of high electricity and natural gas prices which emit lots of harmful gasses and are not that efficient.

Gadalla, M.; Ratlamwala, T.; Dincer, I.

2010-01-01T23:59:59.000Z

153

Operating Range Comments Details on page 149 Curve of constant assigned power rating  

E-Print Network (OSTI)

Flat motor �6 mm, brushless, 0.03 Watt Axial preload > 0.03 N defined through magnetic force between. permissible winding temperature +100°C Weight of motor 0.35 g 8 pole permanent magnet 3 phased coil stator term operation The motor may be briefly overloaded (recurring). Motor with high resistance winding

Ida, Nathan

154

Exergy Analysis and Operational Efficiency of a Horizontal Ground Source Heat Pump System Operated in a Low-Energy Test House under Simulated Occupancy Conditions  

SciTech Connect

This paper presents data, analyses, measures of performance, and conclusions for a ground-source heat pump (GSHP) providing space conditioning to a 345m2 house whose envelope is made of structural insulated panels (SIP). The entire thermal load of this SIP house with RSI-3.7 (RUS-21) walls, triple pane windows with a U-factor of 1.64 W/m2 K (0.29 Btu/h ft2 oF) and solar heat gain coefficient (SHGC) of 0.25, a roof assembly with overall thermal resistance of about RSI-8.8 (RUS-50) and low leakage rates of 0.74 ACH at 50Pa was satisfied with a 2.16-Ton (7.56 kW) GSHP unit consuming negligible (9.83kWh) auxiliary heat during peak winter season. The highest and lowest heating COP achieved was 4.90 (October) and 3.44 (February), respectively. The highest and lowest cooling COP achieved was 6.09 (April) and 3.88 (August). These COPs are calculated on the basis of the total power input (including duct, ground loop, and control power losses ). The second Law (Exergy) analysis provides deep insight into how systemic inefficiencies are distributed among the various GSHP components. Opportunities for design and further performance improvements are identified. Through Exergy analysis we provide a true measure of how closely actual performance approaches the ideal, and it unequivocally identifies, better than energy analysis does, the sources and causes of lost work, the root cause of system inefficiencies.

Ally, Moonis Raza [ORNL; Baxter, Van D [ORNL; Munk, Jeffrey D [ORNL; Gehl, Anthony C [ORNL

2012-01-01T23:59:59.000Z

155

Nuclear mass inventory, photon dose rate and thermal decay heat of spent research reactor fuel assemblies  

SciTech Connect

As part of the Department of Energy`s spent nuclear fuel acceptance criteria, the mass of uranium and transuranic elements in spent research reactor fuel must be specified. These data are, however, not always known or readily determined. It is the purpose of this report to provide estimates of these data for some of the more common research reactor fuel assembly types. The specific types considered here are MTR, TRIGA and DIDO fuel assemblies. The degree of physical protection given to spent fuel assemblies is largely dependent upon the photon dose rate of the spent fuel material. These data also, are not always known or readily determined. Because of a self-protecting dose rate level of radiation (dose rate greater than 100 ren-x/h at I m in air), it is important to know the dose rate of spent fuel assemblies at all time. Estimates of the photon dose rate for spent MTR, TRIGA and DIDO-type fuel assemblies are given in this report.

Pond, R.B.; Matos, J.E.

1996-05-01T23:59:59.000Z

156

Method and apparatus for operating a self-starting air heating system  

DOE Patents (OSTI)

A self-starting, fuel fired, air heating system including a fuel burner fired vapor generator, a turbine, and a condenser connected in a closed circuit such that the vapor output from the vapor generator is conducted to the turbine and then to the condenser where it is condensed for return to the vapor generator. The turbine drives an air blower which passes air over the condenser for cooling the condenser and heating the air. Also, a condensate pump is driven by the turbine. The disclosure is particularly concerned with a method and apparatus which on start-up prevents the vapor generator's vapor output from being conducted to the turbine until a predetermined pressure differential has been achieved. However, after the vapor flow is once permitted, it cannot again be prevented until after the fuel burner has been shut off and restarted.

Heinrich, Charles E. (Mentor, OH)

1983-12-06T23:59:59.000Z

157

Coal flow aids reduce coke plant operating costs and improve production rates  

Science Conference Proceedings (OSTI)

Chemical coal flow aids can provide many benefits to coke plants, including improved production rates, reduced maintenance and lower cleaning costs. This article discusses the mechanisms by which coal flow aids function and analyzes several successful case histories. 2 refs., 10 figs., 1 tab.

Bedard, R.A.; Bradacs, D.J.; Kluck, R.W.; Roe, D.C.; Ventresca, B.P.

2005-06-01T23:59:59.000Z

158

Documentation of the operation of an arc-heated hydrogen atom source  

DOE Green Energy (OSTI)

A detailed description of the operation is given including establishment of an argon arc, changeover to hydrogen, and parameters of the hydrogen arc. A table of arc parameters for an 18 hour period is included. (GHT)

Way, K.R.; Yang, S.C.; Stwalley, W.C.

1976-02-11T23:59:59.000Z

159

The Role of Latent Heat Release in Explosive Cyclogenesis: Three Examples Based on ECMWF Operational Forecasts  

Science Conference Proceedings (OSTI)

Operational forecasts from the European Centre for Medium Range Weather Forecasts of three cases of explosive cyclogenesis of large magnitude that occurred in the North Atlantic during a 1-week period in January 1986 are presented, and results of ...

Richard J. Reed; Mark D. Albright; Adrian J. Sammons; Per Undén

1988-09-01T23:59:59.000Z

160

Thermionic converter with differentially heated cesium-oxygen source and method of operation  

DOE Green Energy (OSTI)

A thermionic converter having an emitter, a collector, and a source of cesium vapor is provided, wherein the source of cesium vapor is differentially heated so that said source has a hotter end and a cooler end, with cesium vapor evaporating from said hotter end into the space between the emitter and the collector and with cesium vapor condensing at said cooler end. The condensed cesium vapor migrates through a porous element from the cooler end to the hotter end.

Rasor, N.S.; Riley, D.R.; Murray, C.S.; Geller, C.B.

1998-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "operating heat rate" 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

Solar water-heating system for the Ingham County geriatric medical care facility, Okemos, Michigan. Operational and maintenance instruction manual  

DOE Green Energy (OSTI)

The objectives of the Ingham County Solar Project include: the demonstration of a major operational supplement to fossil fuels, thereby reducing the demand for non-renewable energy sources, demonstration of the economic and technical feasibility of solar systems as an important energy supplement over the expected life of the building, and to encourage Michigan industry to produce and incorporate solar systems in their own facility. The Ingham County solar system consists of approximately 10,000 square feet of solar collectors connected in a closed configuration loop. The primary loop solution is a mixture of water and propylene glycol which flows through the tube side of a heat exchanger connected to the primary storage tank. The heat energy which is supplied to the primary storage tank is subsequently utilized to increase the temperature of the laundry water, kitchen water, and domestic potable water.

Not Available

1983-07-29T23:59:59.000Z

162

Effect of Heating Rate on the Thermodynamic Properties of Pulverized Coal  

SciTech Connect

This semi-annual technical progress report describes work performed under DOE Grant No.DE-FG22-96PC96224 during the period September 24, 1997 to April 23, 1998 which covers the third six months of the project. During this reporting period, several components of the electrodynamic balance measurement system, Single Particle Laboratory, Federal Energy Technology center, Morgantown, WV, were successfully calibrated. A large number of single polystyrenespheres covering a size range of 80 - 200 microns in diameter were caught in the electrodynamic balance. The size counts of their projected images obtained using the top video-based imaging system, bottom video-based imaging system, and diode-array imaging system were calibrated against the actual size of the particles to within ± 3 microns. Signals obtained by the particle position control system were also calibrated against the actual movement of a polystyrene particle in the balance to within ± 1 microns. Presently, calibration of the Single Color Pyrometer to measure coal particle temperature histories is in progress. Donation agreement for the Heated-Grid measurement system from our industrial partner, United Technologies Research Center (UTRC), CT, was obtained and the arrangement for the completion of the shipment of the grid system components from UTRC to CAU is in progress. Several theoretical analyses were conducted to improve the model performance of the present work and the results were compared with data available from our previous studies. These activities resulted in several publications including three conference papers, and one student poster paper during this reporting period.

Ramanathan Sampath

1998-05-01T23:59:59.000Z

163

Data Assimilation of Satellite-Derived Heating Rates as Proxy Surface Wetness Data into a Regional Atmospheric Mesoscale Model. Part I: Methodology  

Science Conference Proceedings (OSTI)

A satellite data assimilation method is developed which incorporates satellite-observed infrared heating rates into a mesoscale atmospheric model to retrieve model soil moisture. The method builds upon previous work with the model’s surface ...

Andrew S. Jones; Ingrid C. Guch; Thomas H. Vonder Haar

1998-03-01T23:59:59.000Z

164

Data Assimilation of Satellite-Derived Heating Rates as Proxy Surface Wetness Data into a Regional Atmospheric Mesoscale Model. Part II: A Case Study  

Science Conference Proceedings (OSTI)

A satellite data assimilation method is applied which incorporates satellite-observed heating infrared rates into a mesoscale atmospheric model to retrieve model soil moisture. In a 3D case study, the method is successful at retrieving realistic ...

Andrew S. Jones; Ingrid C. Guch; Thomas H. Vonder Haar

1998-03-01T23:59:59.000Z

165

Experimental Study on Operating Characteristic of the System of Ground Source Heat Pump Combined with Floor Radiant Heating of Capillary Tube  

Science Conference Proceedings (OSTI)

At first, the article presented particularly the working theory of the system of ground source heat pump combined with floor radiant heating of capillary tube, the characteristic of soil layers and the arrangement form of capillary tube mat and the floor ... Keywords: Ground source heat pump, Capillary tube, Radiant heating, Characteristic, Experiment

Yunzhun Fu; Cai Yingling; Jing Li; Yeyu Wang

2009-10-01T23:59:59.000Z

166

Operating efficiencies of a Lysholm, helical expander for Brayton-Cycle heat engines  

Science Conference Proceedings (OSTI)

Operating tests on a Lysholm helical expander have been done to develop a data base for comparing the performance of helical expanders with turbine expanders by using simple scaling arguments. The eventual goal of such work would be to develop a rugged and reliable ceramic helical expander for operating at temperatures up to 1300/sup 0/C (2400/sup 0/F). The authors used a 127.5 mm (5.020 in.) metal expander on which they measured seven performance variables against applied pressure ratio at six shaft speeds and an inlet gas temperture of 100/sup 0/C (212/sup 0/F). The data system included: a torque and angular-speed cell to measure power; flow, pressure, and temperature instrumentation; and a data reduction program. Test results are presented in seven data plots; equations for computing the performance variables are tabulated. Adiabatic efficiency was found to be at least 85% in the pressure ratio range of 2.75 to 5.00. Performance is strongly influenced by gas leakage. Large machines with clearance ratios the same as smaller machines would benefit by size scaling effects. The authors expect that ceramic helical expanders for 1300/sup 0/C service would be able to operate at adiabatic efficiencies higher than 85%.

Myers, B.; Deis, G.; Shell, T.

1986-01-01T23:59:59.000Z

167

Operating efficiencies of a Lysholm helical expander for Brayton-cycle heat engines  

Science Conference Proceedings (OSTI)

Operating tests on a Lysholm helical expander have been done to develop a data base for comparing the performance of helical expanders with turbine expanders by using simple scaling arguments. The eventual goal of such work would be to develop a rugged and reliable ceramic helical expander for operating at temperatures up to 1300/sup 0/C (2400/sup 0/F). We used a 127.5 mm (5.020 in.) metal expander on which we measured seven performance variables against applied pressure ratio at six shaft speeds and an inlet gas temperature of 100/sup 0/C (212/sup 0/F). Our data system included: a torque and angular-speed cell to measure power; flow, pressure, and temperature instrumentation; and a data reduction program. Test results are presented in seven data plots; equations for computing the performance variables are tabulated. Adiabatic efficiency was found to be at least 85% in the pressure ratio range of 2.75 to 5.00. Performance is strongly influenced by gas leakage. Large machines with clearance ratios the same as smaller machines would benefit by size scaling effects. We expect that ceramic helical expanders for 1300/sup 0/C service would be able to operate at adiabatic efficiencies higher than 85%. 9 refs., 12 figs., 1 tab.

Myers, B.; Deis, G.; Shell, T.

1986-01-01T23:59:59.000Z

168

Refinery Operable Utilization Rate  

U.S. Energy Information Administration (EIA)

-No Data Reported; --= Not Applicable; NA = Not Available; W = Withheld to avoid disclosure of individual company data. Notes: Totals may not equal sum ...

169

Furnace Design and Operation  

Science Conference Proceedings (OSTI)

...S. Lampman, Energy-Efficient Heat-Treating Furnace Design and Operation, Heat Treating, Vol 4, ASM Handbook, ASM International,

170

Equatorial Waves in the Upper Troposphere and Lower Stratosphere Forced by Latent Heating Estimated from TRMM Rain Rates  

Science Conference Proceedings (OSTI)

Equatorial atmospheric waves in the upper troposphere and lower stratosphere (UTLS), excited by latent heating, are investigated by using a global spectral model. The latent heating profiles are derived from the 3-hourly Tropical Rainfall ...

Jung-Hee Ryu; M. Joan Alexander; David A. Ortland

2011-10-01T23:59:59.000Z

171

THERMAL DESIGN METHODOLOGY FOR LOW FLOW RATE SINGLE-PHASE AND TWO-PHASE MICRO-CHANNEL HEAT SINKS  

E-Print Network (OSTI)

in Engine Cooling Systems,'' Experimental Heat Transfer, Fluid Mechanics, and Thermodynamics 1997, June 1997, ``A Correlation for Boiling Heat Transfer to Saturated Fluids in Convective Flow,'' Ind. Eng. Chem the engines in automotive applications. Heat is transferred essentially under subcooled flow boiling

Qu, Weilin

172

Doubly Fed Induction Generator in an Offshore Wind Power Plant Operated at Rated V/Hz: Preprint  

NLE Websites -- All DOE Office Websites (Extended Search)

Doubly Fed Induction Generator Doubly Fed Induction Generator in an Offshore Wind Power Plant Operated at Rated V/Hz Preprint Eduard Muljadi, Mohit Singh, and Vahan Gevorgian To be presented at the IEEE Energy Conversion Congress and Exhibition Raleigh, North Carolina September 15-20, 2012 Conference Paper NREL/CP-5500-55573 June 2012 NOTICE The submitted manuscript has been offered by an employee of the Alliance for Sustainable Energy, LLC (Alliance), a contractor of the US Government under Contract No. DE-AC36-08GO28308. Accordingly, the US Government and Alliance retain a nonexclusive royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes. This report was prepared as an account of work sponsored by an agency of the United States government.

173

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. The heat pump part of the system heats or cools a house or other structure through a combination of evaporation and absorption or, conversely, condensation and desorption, in a pair of containers. A set of automatic controls change the system for operation during winter and summer months and for daytime and nighttime operation to satisfactorily heat and cool a house during an entire year. The absorber chamber is subjected to solar heating during regeneration cycles and is covered by one or more layers of glass or other transparent material. Daytime home air used for heating the home is passed at appropriate flow rates between the absorber container and the first transparent cover layer in heat transfer relationship in a manner that greatly reduce eddies and resultant heat loss from the absorbant surface to ambient atmosphere.

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

1980-01-01T23:59:59.000Z

174

Heat pipe heat amplifier  

SciTech Connect

In a heat pipe combination consisting of a common condenser section with evaporator sections at either end, two working fluids of different vapor pressures are employed to effectively form two heat pipe sections within the same cavity to support an amplifier mode of operation.

Arcella, F.G.

1978-08-15T23:59:59.000Z

175

Measured Impact on Space Conditioning Energy Use in a Residence Due to Operating a Heat Pump Water Heater inside the Conditioned Space  

Science Conference Proceedings (OSTI)

The impact on space conditioning energy use due to operating a heat pump water heater (HPWH) inside the conditioned space is analyzed based on 2010-2011 data from a research house with simulated occupancy and hot water use controls. The 2700 ft2 (345 m2) house is located in Oak Ridge, TN (mixed-humid climate) and is equipped with a 50 gallon (189 l) HPWH that provided approximately 55 gallons/d (208 l/d) of hot water at 120 F (46 C) to the house during the test period. The HPWH has been operated every other week from December 2010 through November 2011 in two modes; a heat pump only mode, and a standard mode that utilizes 15355 Btu/hr (4500 W) resistance heating elements. The energy consumption of the air-source heat pump (ASHP) that provides space conditioning for the house is compared for the two HPWH operating modes with weather effects taken into account. Impacts during the heating and cooling seasons are compared.

Munk, Jeffrey D [ORNL; Ally, Moonis Raza [ORNL; Baxter, Van D [ORNL

2012-01-01T23:59:59.000Z

176

Heat transfer characteristics of a three-phase volume boiling direct contact heat exchanger  

DOE Green Energy (OSTI)

The advantages of direct contact heat transfer over heat transfer utilizing conventional metallic heat exchangers are listed. The performance characteristics of a three-phase direct contact heat exchanger in near counterflow operation were evaluated using water as the continuous phase fluid and refrigerant 113 as the dispersed phase fluid. Conclusions are drawn from the results having to do with refrigerant injection technique, vessel operating height, mass flow rate of refrigerant, water inlet temperature, operation at pinch point temperature differences below 13 to 20/sup 0/C, and operation with a dispersed phase fluid less dense than water. (MHR)

Blair, C.K.; Boehm, R.F.; Jacobs, H.R.

1976-03-01T23:59:59.000Z

177

Optimizing the heat pipe for operation in a magnetic field when liquid-metal working fluids are used  

SciTech Connect

A novel method for reducing the magnetohydrodynamic (MHD) pressure drops in the liquid metal flow in a heat pipe wick is described. By flattening the heat pipe, the eddy current return path in the metallic heat pipe wall is inreased significantly, thereby increasing the effective wall resistance. This, in turn, reduces the magnitude of the MHD pressure drop. The same principle can also be applied to flows of liquid metal coolants in a magnetic field.

Werner, R.W.; Hoffman, M.A.

1981-05-18T23:59:59.000Z

178

Heat and Buoyancy Budgets and Mixing Rates in the Upper Thermocline of the Indian and Global Oceans  

Science Conference Proceedings (OSTI)

Diapycnal and diathermal diffusivity values in the upper thermocline are estimated from buoyancy and heat budgets for water volumes bounded by isopycnals and isotherms, the air–sea interface, and coastline where applicable. Comprehensive analysis ...

Huai-Min Zhang; Lynne D. Talley

1998-10-01T23:59:59.000Z

179

Topic 14. Retrofit and optimal operation of the building energy systems Performances of Low Temperature Radiant Heating Systems  

E-Print Network (OSTI)

panel system are given by its energy (the consumption of gas for heating, electricity for pumps for residential buildings are increasingly used. According to some studies, this figure exceeds 50% (Kilkis et al of new calculation methods. However, in terms of heat transfer modelling, there are several analytical

Paris-Sud XI, Université de

180

A Modified Analytical Method for Simulating Cyclic Operation of Vertical U-Tube Ground-Coupled Heat Pumps  

E-Print Network (OSTI)

A modified analytical model is presented which discretizes the ground-coupled heat exchanger of a ground-coupled heat pump and utilized a separate cylindrical source solution for each element. First law expressions are utilized for each element to derive a set of fully implicit finite difference equations for the pipe wall temperature and the fluid temperature profile inside the ground-coupled heat exchanger. This method entails less computational overhead than methods which utilize numerical solutions inside the soil, and comes closer than previous analytical methods to satisfying the constant heat flux assumption of the original analytical solution. The thermal capacitance effects of the fluid inside the ground-coupled heat exchanger are included to allow proper prediction of the entering water temperature (EWT) profile at start-up. Comparisons with experimental data on EWT, capacity, energy input and cycling are provided.

Dobson, M. K.; O'Neal, D. L.; Aldred, W.

1994-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "operating heat rate" 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

Heat transfer and heat exchangers reference handbook  

Science Conference Proceedings (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

182

Operations & Maintenance  

NLE Websites -- All DOE Office Websites (Extended Search)

Rates Operations & Maintenance Operations OASIS: WACM (Note: this site is not hosted by Western and requires a digital certificate and login for full access.) wesTTrans Common...

183

Doubly Fed Induction Generator in an Offshore Wind Power Plant Operated at Rated V/Hz: Preprint  

DOE Green Energy (OSTI)

This paper introduces the concept of constant Volt/Hz operation of offshore wind power plants. The deployment of offshore WPPs requires power transmission from the plant to the load center inland. Since this power transmission requires submarine cables, there is a need to use High-Voltage Direct Current transmission, which is economical for transmission distances longer than 50 kilometers. In the concept presented here, the onshore substation is operated at 60 Hz synced with the grid, and the offshore substation is operated at variable frequency and voltage, thus allowing the WPP to be operated at constant Volt/Hz.

Muljadi, E.; Singh, M.; Gevorgian, V.

2012-06-01T23:59:59.000Z

184

NBSBR 84-2867 Test Procedures for Rating  

E-Print Network (OSTI)

NBSBR 84-2867 Test Procedures for Rating Residential Heating and Cooling Absorption Equipment U HEATING AND COOLING ABSORPTION EQUIPMENT Brian Weber Reinhard Radermacher David Didion U.S. DEPARTMENT-fired absorption devices operating in either the heating or cooling modes. These procedures are designed to include

Oak Ridge National Laboratory

185

Performance Testing Residential Heat Pump Water Heaters under South- and Central-Florida Climate Conditions: Hot, Humid Climate and Warm Ground Water Pose Unusual Operating Environment for Heat Pump Water Heaters  

Science Conference Proceedings (OSTI)

Heat pump water heaters (HPWHs) are known to provide considerable energy savings compared with electric resistance devices in many applications. However, as their performance is climate-dependent, it is important to understand their operation in extreme climates. Southern and Central Florida presents an extreme climate for HPWHs, as the air temperature, humidity, and entering water temperatures are all high nearly year-round. This report examines HPWH performance in the Florida Power & Light ...

2013-09-30T23:59:59.000Z

186

Volatile compound evolution from the programmed temperature pyrolysis of Big Clifty and McKittrick tar sands at a 10 degrees C/min heating rate  

DOE Green Energy (OSTI)

Big Clifty (Kentucky) and McKittrick (California) tar sands were pyrolyzed at a 10{degrees}C/min heating rate from room temperature to 900{degrees}C. The volatile compounds were detected on-line and in real time by tandem mass spectrometry using MS and MS/MS detection. This paper reports the programmed temperature pyrolysis behaviors of Big Clifty and McKittrick tar sands and compares their results. 48 refs., 10 figs., 3 tabs.

Reynolds, J.G.

1989-11-01T23:59:59.000Z

187

Self-contained passive solar heating system  

SciTech Connect

A self-contained passive solar heating system includes first and second heat pipes, each having a refrigerant medium therein, a condenser portion and an evaporator portion, with the condenser portion of the first heat pipe being coupled to the evaporator portion of the second heat pipe for transferring heat thereto when the pressure within the first heat pipe is greater than the pressure within the second heat pipe. The evaporator portion of the first heat pipe is adapted to be exposed to a source of heat and the condenser portion of the second heat pipe contacts a medium to be heated. A temperature control mechanism may be installed as the coupling between the first and second heat pipes for uncoupling the same when the temperature within the first heat pipe falls below a predetermined temperature. Also, a third heat pipe may be provided having a thermostatic portion operatively connected to the condenser portion of the second heat pipe by a piston means so that changes in pressure within the thermostatic portion occasioned by changes in temperature of the medium to be heated will cause movement of the pistons to vary the size of the condensing portion of the second heat pipe to increase or decrease the rate of heat transfer to the medium.

Maldonado, E.A.; Woods, J.E.

1983-05-10T23:59:59.000Z

188

High temperature heat pipes for waste heat recovery  

SciTech Connect

Operation of heat pipes in air at temperatures above 1200/sup 0/K has been accomplished using SiC as a shell material and a chemical vapor deposit (CVD) tungsten inner liner for protection of the ceramic from the sodium working fluid. The CVD tungsten has been used as a distribution wick for the gravity assisted heat pipe through the development of a columnar tungsten surface structure, achieved by control of the metal vapor deposition rate. Wick performance has been demonstrated in tests at approximately 2 kW throughput with a 19-mm-i.d. SiC heat pipe. Operation of ceramic heat pipes in repeated start cycle tests has demonstrated their ability to withstand temperature rise rates of greater than 1.2 K/s.

Merrigan, M.A.; Keddy, E.S.

1980-01-01T23:59:59.000Z

189

Operation of a low temperature absorption chiller at rating point and at reduced evaporator temperature. Final report  

DOE Green Energy (OSTI)

The returned SAM 015 (fifteen ton Solar Absorption Machine) chiller was given a cursory visual inspection, some obvious problems were remedied, and then it was placed on a test stand to get a measure of dirty performance. It was then given a standard acid clean, the water side of the tubes was brushed clean, and then the machine was retested. The before and after cleaning data were compared to equivalent data taken before the machine was shipped. The second part of our work statement was to experimentally demonstrate the technical feasibility of operating the chiller at evaporator temperatures below O/sup 0/C (32/sup 0/F) and identify any operational problems.

Best, R.; Biermann, W.; Reimann, R.

1985-01-01T23:59:59.000Z

190

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)

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

Bahrami, Majid

191

Liquid metal heat pipe behavior under transient cooling and heating  

SciTech Connect

This paper describes the results of an experimental investigation of the transient behavior of a liquid metal heat pipe. A 0.457 m long, screen-wick, sodium heat pipe with 0.0127 m outer diameter was tested in sodium loop facility. The heat pipe reversed under a pulse heat load applied at the condenser. The time at which the heat pipe reversed was dependent of the heat pipe properties, the sodium loop flow rate and heating conditions at the condenser. The start-up and the operational shut-down by forced cooling of the condenser were also studied. During the start-up process, at least part of the heat pipe was active. The active region extended gradually down to the end of the condenser until all working fluid in the heat pipe was molten. With forced cooling at the condenser, the heat pipe approached its heat transport limit before section of the condenser became frozen. The measured heat transport limit was in agreement with the theoretical value. 5 refs.

Nguyen, H.X.; Hahn, T.O.; Hahn, O.J.; Chow, L.C.; Tagavi, K.A.; Morgan, M.J. (Kentucky, University, Lexington (United States) USAF, Wright Laboratory, Wright-Patterson AFB, OH (United States))

1992-01-01T23:59:59.000Z

192

Heat Sink Performance Analysis through Numerical Technique  

E-Print Network (OSTI)

The increase in dissipated power per unit area of electronic components sets higher demands on the performance of the heat sink. Also if we continue at our current rate of miniaturisation, laptops and other electronic devices can get heated up tremendously. Hence we require a better heat dissipating system to overcome the excess heat generating problem of using nanoelectronics, which is expected to power the next generation of computers. To handle the excessive and often unpredictable heating up of high performance electronic components like microprocessors, we need to predict the temperature profile of the heat sink used. This also helps us to select the best heat sink for the operating power range of any microprocessor. Understanding the temperature profile of a heat sink and a microprocessor helps us to handle its temperature efficiently for a range of loads. In this work, a method to estimate the normal response of a heat sink to various loads of a microprocessor is explained.

Aravindh, B Sri; Nair, T R Gopalakrishnan

2010-01-01T23:59:59.000Z

193

ABSORPTION HEAT PUMP IN THE DISTRICT HEATING  

E-Print Network (OSTI)

#12;ABSORPTION HEAT PUMP IN THE DISTRICT HEATING PLANT Dr.sc.ing. Agnese Lickrastina M.Sc. Normunds European Heat Pump Summit 2013, Nuremberg, 15-16.10.2013 · Riga District Heating company · Operation #12;JSC RGAS SILTUMS · the biggest District Heating company in Latvia and in the Baltic states

Oak Ridge National Laboratory

194

Cavity-enhanced radiative emission rate in a single-photon-emitting diode operating at 0.5 GHz  

E-Print Network (OSTI)

We report the observation of a Purcell enhancement in the electroluminescence decay rate of a single quantum dot, embedded in a microcavity light-emitting-diode structure. Lateral confinement of the optical mode was achieved using an annulus of low-refractive-index aluminium oxide, formed by wet oxidation. The same layer acts as a current aperture, reducing the active area of the device without impeding the electrical properties of the p-i-n diode. This allowed single photon electroluminescence to be demonstrated at repetition rates up to 0.5 GHz.

David J. P. Ellis; Anthony J. Bennett; Samuel J. Dewhurst; Christine A. Nicoll; David A. Ritchie; Andrew J. Shields

2008-04-04T23:59:59.000Z

195

Quarterly technical progress report No. 2, December 20-March 19, 1982. Second quarterly report on the effect of rapid heating rate on coal nitrogen and sulfur release  

Science Conference Proceedings (OSTI)

A laser pyrolysis technique is applied to the investigation of the effects of heating rate on release of coal-bound sulfur and nitrogen. An experimental system characterization and calibration has been completed. A detailed documentation was prepared describing the 3-color pyrometer and the data analysis technique. The coal particle feed system has been calibrated to provide accurate mass flow rate at pre-selected particle velocities. The first batch of samples submitted for chemical analysis will be used for the determination of kinetics parameters at a high heating rate (approximately equal to 10/sup 6/ K/s). The coal used presently is a Montana Rosebud. Two other coals are available; one is ILL No. 6 (through EERC) which will need to be pulverized and the second is a Pitt. hv-A (through KVB). It was confirmed that sieve and drag size distribution of coal differ significantly, and that particle shape effects may be significant in the modelling of particle dynamics.

Gat, N.

1982-04-26T23:59:59.000Z

196

System Modeling of Gas Engine Driven Heat Pump  

SciTech Connect

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

2012-01-01T23:59:59.000Z

197

Micro-Columnated Loop Heat Pipe: The Future of Electronic Substrates  

E-Print Network (OSTI)

Loop Heat Pipes . . . . . . . . . . . . . . . . . . . .Heat Pipes . . . . . . . . . . . . . . . . . . . . . . . .of operation of a heat pipe [13]. . . . . . . . . . . . . .

Dhillon, Navdeep Singh

2012-01-01T23:59:59.000Z

198

Dual source heat pump  

DOE Patents (OSTI)

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

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

1982-01-01T23:59:59.000Z

199

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

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

200

Oil shale retorting: a correlation of selected infrared absorbance bands with process heating rates and oil yeild  

DOE Green Energy (OSTI)

The measured absorbance for specific infrared bands of Colorado shale oil is correlated with process oil yield and retorting rate. The results show excellent correlations using bands associated with olefinic groups (910, 990 and 1640 cm/sup -1/); analyses were carried out using both quantitative and qualitative infrared methods. No pretreatment of the crude shale oil is required. The results are encouraging enough that, with further development, the method may have potential use as an on-line monitoring technique for various retorting processes.

Evans, R.A.; Campbell, J.H.

1979-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "operating heat rate" 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

Energy savings from operation and maintenance training for apartment boiler heating systems. An energy study on ten low-income apartments  

SciTech Connect

The Portland Energy Office provided operation and maintenance (O&M) training to the operators of boiler heating systems for ten low-income apartment complexes in the Fall of 1990. This study tracked energy usage before and after O&M training to see if savings occurred. Training was provided on both weatherized and non-weatherized apartments to find out if weatherization impacted the amount of O&M savings to be obtained. Also, energy savings from the O&M training and building shell weatherization are compared. The O&M training averaged about four hours per building. Content was adjusted at each site to match needs of the boiler and operator. The Energy Office also provided a boiler tune-up by a service technician. The training stressed low-cost and no-cost measures which operators could either do themselves or hire service help to implement. It also emphasized boiler safety. Nine of the ten apartment complexes in the study used less energy per heating degree-day after the O&M help. Average savings were 10%. Four apartments chosen randomly as controls had negative savings; they used slightly more energy during the same post-O&M time frame. Weatherized and unweatherized apartments showed similar savings after the O&M help, 10% and 11% percent respectively. Savings from weatherization of six of the apartments in the winter of 1988--1989 were also measured. A low average of only 4% was observed, reflecting negative savings in two buildings.

1992-02-01T23:59:59.000Z

202

Analysis of Cyclic Variability of Heat Release for High-EGR GDI Engine Operation with Observations on Implications for Effective Control  

Science Conference Proceedings (OSTI)

Operation of spark-ignition (SI) engines with high levels of charge dilution through exhaust gas recirculation (EGR) achieves significant engine efficiency gains while maintaining stoichiometric operation for compatibility with three-way catalysts. Dilution levels, however, are limited by cyclic variability-including significant numbers of misfires-that becomes more pronounced with increasing dilution. This variability has been shown to have both stochastic and deterministic components. Stochastic effects include turbulence, mixing variations, and the like, while the deterministic effect is primarily due to the nonlinear dependence of flame propagation rates and ignition characteristics on the charge composition, which is influenced by the composition of residual gases from prior cycles. The presence of determinism implies that an increased understanding the dynamics of such systems could lead to effective control approaches that allow operation near the edge of stability, effectively extending the dilution limit. This nonlinear dependence has been characterized previously for homogeneous charge, port fuel-injected (PFI) SI engines operating fuel-lean as well as with inert diluents such as bottled N2 gas. In this paper, cyclic dispersion in a modern boosted gasoline direct injection (GDI) engine using a cooled external EGR loop is examined, and the potential for improvement with effective control is evaluated through the use of symbol sequence statistics and other techniques from chaos theory. Observations related to the potential implications of these results for control approaches that could effectively enable engine operation at the edge of combustion stability are noted.

Kaul, Brian C [ORNL; Wagner, Robert M [ORNL; Green Jr, Johney Boyd [ORNL

2013-01-01T23:59:59.000Z

203

Impact of a revised $^{25}$Mg(p,$?$)$^{26}$Al reaction rate on the operation of the Mg-Al cycle  

E-Print Network (OSTI)

Proton captures on Mg isotopes play an important role in the Mg-Al cycle active in stellar H-burning regions. In particular, low-energy nuclear resonances in the $^{25}$Mg(p,$\\gamma$)$^{26}$Al reaction affect the production of radioactive $^{26}$Al$^{gs}$ as well as the resulting Mg/Al abundance ratio. Reliable estimations of these quantities require precise measurements of the strengths of low-energy resonances. Based on a new experimental study performed at LUNA, we provide revised rates of the $^{25}$Mg(p,$\\gamma$)$^{26}$Al$^{gs}$ and the $^{25}$Mg(p,$\\gamma$)$^{26}$Al$^{m}$ reactions with corresponding uncertainties. In the temperature range 50 to 150 MK, the new recommended rate of the $^{26}$Al$^{m}$ production is up to 5 times higher than previously assumed. In addition, at T$=100$ MK, the revised total reaction rate is a factor of 2 higher. Note that this is the range of temperature at which the Mg-Al cycle operates in an H-burning zone. The effects of this revision are discussed. Due to the significantly larger $^{25}$Mg(p,$\\gamma$)$^{26}$Al$^{m}$ rate, the estimated production of $^{26}$Al$^{gs}$ in H-burning regions is less efficient than previously obtained. As a result, the new rates should imply a smaller contribution from Wolf-Rayet stars to the galactic $^{26}$Al budget. Similarly, we show that the AGB extra-mixing scenario does not appear able to explain the most extreme values of $^{26}$Al/$^{27}$Al, i.e. $>10^{-2}$, found in some O-rich presolar grains. Finally, the substantial increase of the total reaction rate makes the hypothesis of a self-pollution by massive AGBs a more robust explanation for the Mg-Al anticorrelation observed in Globular-Cluster stars.

O. Straniero; G. Imbriani; F. Strieder; D. Bemmerer; C. Broggini; A. Caciolli; P. Corvisiero; H. Costantini; S. Cristallo; A. DiLeva; A. Formicola; Z. Elekes; Zs. Fülöp; G. Gervino; A. Guglielmetti; C. Gustavino; Gy. Gyürky; M. Junker; A. Lemut; B. Limata; M. Marta; C. Mazzocchi; R. Menegazzo; L. Piersanti; P. Prati; V. Roca; C. Rolfs; C. Rossi Alvarez; E. Somorjai; F. Terrasi; H. P. Trautvetter

2012-11-28T23:59:59.000Z

204

Multiple source heat pump  

DOE Patents (OSTI)

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

Ecker, Amir L. (Duncanville, TX)

1983-01-01T23:59:59.000Z

205

Heating Rates in Tropical Anvils  

Science Conference Proceedings (OSTI)

The interaction of infrared and solar radiation with tropical cirrus anvils is addressed. Optical properties of the anvils are inferred from satellite observations and from high-altitude aircraft measurements. An infrared multiple-scattering ...

Thomas P. Ackerman; Kuo-Nan Liou; Francisco P. J. Valero; Leonhard Pfister

1988-05-01T23:59:59.000Z

206

Impact of a revised $^{25}$Mg(p,$\\gamma$)$^{26}$Al reaction rate on the operation of the Mg-Al cycle  

E-Print Network (OSTI)

Proton captures on Mg isotopes play an important role in the Mg-Al cycle active in stellar H-burning regions. In particular, low-energy nuclear resonances in the $^{25}$Mg(p,$\\gamma$)$^{26}$Al reaction affect the production of radioactive $^{26}$Al$^{gs}$ as well as the resulting Mg/Al abundance ratio. Reliable estimations of these quantities require precise measurements of the strengths of low-energy resonances. Based on a new experimental study performed at LUNA, we provide revised rates of the $^{25}$Mg(p,$\\gamma$)$^{26}$Al$^{gs}$ and the $^{25}$Mg(p,$\\gamma$)$^{26}$Al$^{m}$ reactions with corresponding uncertainties. In the temperature range 50 to 150 MK, the new recommended rate of the $^{26}$Al$^{m}$ production is up to 5 times higher than previously assumed. In addition, at T$=100$ MK, the revised total reaction rate is a factor of 2 higher. Note that this is the range of temperature at which the Mg-Al cycle operates in an H-burning zone. The effects of this revision are discussed. Due to the significa...

Straniero, O; Strieder, F; Bemmerer, D; Broggini, C; Caciolli, A; Corvisiero, P; Costantini, H; Cristallo, S; DiLeva, A; Formicola, A; Elekes, Z; Fülöp, Zs; Gervino, G; Guglielmetti, A; Gustavino, C; Gyürky, Gy; Junker, M; Lemut, A; Limata, B; Marta, M; Mazzocchi, C; Menegazzo, R; Piersanti, L; Prati, P; Roca, V; Rolfs, C; Alvarez, C Rossi; Somorjai, E; Terrasi, F; Trautvetter, H P

2012-01-01T23:59:59.000Z

207

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

NLE Websites -- All DOE Office Websites (Extended Search)

exchanger. | Photo from iStockphoto.com Heat Exchangers for Solar Water Heating Systems Rooftop solar water heaters need regular maintenance to operate at peak efficiency. |...

208

Comparative performance of two types of evacuated tubular solar collectors in a residential heating and cooling system. Final report, October 1 1977-September 30 1978 (including 1974-1977 operating results comparisons)  

DOE Green Energy (OSTI)

Two types of evacuated tubular solar collectors have been operated in space heating, cooling, and domestic hot water heating systems in Colorado State University Solar House I. An experimental collector from Corning Glass works supplied heat to the system from January 1977 through February 1978, and an experimental collector from the Phillips Research Laboratory, Aachen, which is currently in use, has been operating since August 1978. A flat absorber plate inside a single-walled glass tube is used in the Corning design, whereas heat is conducted through a single glass wall to an external heat exchanger plate in the Philips collector. The respective aperture areas are 50.0 m/sup 2/ and 44.7 m/sup 2/. Since system designs and conditions of operation were not identical, efficiencies and energy deliveries of the two evacuated tubular collectors should not be compared without recognition of these factors. But in comparison with conventional flat plate collectors, both types show substantially reduced heat losses and improved efficiency.

Loef, G.O.G.; Duff, W.S.

1979-09-01T23:59:59.000Z

209

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

210

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

211

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

212

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

213

Rates & Repayment  

NLE Websites -- All DOE Office Websites (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

214

Niobium 1% zirconium/potassium and titanium/potassium life-test heat pipe design and testing  

SciTech Connect

Experimental lifetime performance studies currently in progress use Niobium-1% Zirconium (Nb-1Zr) and Titanium (Ti) heat pipes with potassium (K) as the working fluid. A heat pipe life-test matrix has been developed for testing the heat pipes. Because the corrosion rates in alkali metal heat pipes are affected by temperature and working fluid evaporation flux, the variable parameters of the experimental matrix are established as steady operating temperature and input heat flux density. Total impurity inventory is a factor in corrosion rate so impurity levels are being evaluated in the heat pipe materials before and after testing. Eight Nb-1Zr/K heat pipes were designed, fabricated, and tested. Two of the heat pipes have completed testing whereas the other six are currently in test. These are gravity-assist heat pipes operating in a reflux mode. The heat pipes are tested by sets, one set of two and two sets of three heat pipes. Three Ti/K heat pipes are also in life test. These heat pipes are tested as a set in a horizontal position in a capillary pumped annular flow mode. Each of the heat pipes is encapsulated in a quartz vacuum container with a water calorimeter over the vacuum container for power throughput measurements. Thermocouples are attached to the heat pipes for measuring temperature. Heat input to the heat pipes is via an rf coil. The heat pipes are operating at between 800 and 900 K, with heat input fluxes of 13.8 to 30 W/sq cm. Of the Nb-1Zr/K heat pipes, two of the heat pipes have been in operation for 14,000 hours, three over 10,000 hours, and three over 7,000 hours. The Ti/K heat pipes have been in operation for 1,266 hours. 5 refs., 4 figs., 1 tab.

Sena, J.T.; Merrigan, M.A.

1989-01-01T23:59:59.000Z

215

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 the different forms of heating systems suited for single household metering. We introduce especially the single house horizontal spanning system and show how to select the heat flow rate of the radiator. We also study the distribution rule of the heat intermedium of horizontal heating system. To simplify the workload of engineering process and make the design more accurate, a new method for calculating the average temperature of the intermedium and the heat flow rate of this heating system is put forward. Comparison is also made between the system in question and the heating system in series. A few important questions are raised and discussed, such as the computation of combining different forms of radiators, the verification of the pipe radiation, the end of the radiator without spanning pipe, and the selection of the pipe diameter. At the same time, we study the influence of the horizontal heating system on the whole heating network, describe the characteristics of a single household horizontal heating system and the importance of its hydraulic computation, and analyze the influence of the gravitational head to this heating system. We also study the hydraulic condition of the single house horizontal system and the relationship of each party under the adjustment. In addition, the operation of single household horizontal heating system is verified in a real project, and its reliability is testified. This paper provides a method for further research on related issues of a single household metering heating system and is valuable for design, operation and management.

Hang, Y.; Ying, D.

2006-01-01T23:59:59.000Z

216

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

217

Current developments in oil shale research at the Laramie Energy Research Center. [Review of studies in 4 areas: concurrent gasification and retorting; high pressure retorting; abnormal heating rate of interior of large blocks of oil shale; and in-situ combustion  

DOE Green Energy (OSTI)

Current oil shale research being conducted at the Laramie Energy Research Center is many faceted, and some of the recent developments in these areas are presented. Concurrent gasification and retorting of oil shale where the effects of operating pressure and amounts of oxygen and water injection on quality and quantity of gas and oil produced is being studied. This work has resulted in off gas with heating values varying from 50 to 1,300 Btu/ft/sup 3/ and oil recovery of up to 80 vol percent of Fischer assay. The effects of retorting atmosphere, pressure, and external heating rate are being studied in a high pressure batch retort. Results from this work indicate that a nitrogen atmosphere decreases oil yield slightly while a hydrogen atmosphere increases the oil yield significantly. Large blocks of oil shale are being retorted in a 150-ton aboveground retort to study the abnormal heating rate of the interior of the blocks. This could be caused by an oxidation exotherm similar to that found in limited DTA studies. Some early results from the Rock Springs site 9 in-situ experiment are also presented. This is the fifth in-situ combustion experiment and is being performed in a 40-foot-thick oil shale bed having an average Fischer assay of 23 gallons per ton.

Jacobson, I.A. Jr.; Burwell, E.L.; Harak, A.E.; Long, A.; Wise, R.L.

1976-01-01T23:59:59.000Z

218

Energy extraction operations: some preliminary results  

DOE Green Energy (OSTI)

An experimental project being conducted by the Los Alamos Scientific Laboratory (LASL) has extracted thermal energy from Precambrian granitic rock by injection and circulating water through fractured zones or reservoirs. Two boreholes were drilled to depths of about 3 km (10,000 ft) in a location selected for high heat flow and an apparent lack of faulting. Bottom-hole temperature was 205/sup 0/C (400/sup 0/F). The holes were connected at depth by hydraulic fracturing to form a flow path and heat extraction surface. Energy has been extracted at rates exceeding 5 MW(t) in three operations totaling 2847 h. These operations are summarized.

Hendron, R.H.

1979-01-01T23:59:59.000Z

219

Heat exchanger  

DOE Patents (OSTI)

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

Wolowodiuk, Walter (New Providence, NJ)

1976-01-06T23:59:59.000Z

220

Energy Efficiency Interest Rate Reduction Program | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Interest Rate Reduction Program Energy Efficiency Interest Rate Reduction Program Eligibility Residential Savings For Heating & Cooling Home Weatherization Construction Commercial...

Note: This page contains sample records for the topic "operating heat rate" 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

METHOD OF OPERATING A CALUTRON  

DOE Patents (OSTI)

A method of operating an electromagnetic isotope separator of the calutron class is reported whereby uranium tetrachloride is produced at a controlled rate within the source rather than betng introduced therein as was formerly practiced. This is accomplished by placing a uranium-bearing material, such as uranium metal, uranium trichloride, or uranium carbide in the charge receptacle of the calutron, heating this material to about to produce uranium tetrachloride vapor at a rate controlled by the chlorine gas flow into the source. The vapor is subsequently ionized by an electric arc and mass separated by conventional calutron methods.

Davidson, P.H.

1960-01-12T23:59:59.000Z

222

Advanced Heat Transfer and Thermal Storage Fluids  

DOE Green Energy (OSTI)

The design of the next generation solar parabolic trough systems for power production will require the development of new thermal energy storage options with improved economics or operational characteristics. Current heat-transfer fluids such as VP-1?, which consists of a eutectic mixture of biphenyl and diphenyl oxide, allow a maximum operating temperature of ca. 300 C, a limit above which the vapor pressure would become too high and would require pressure-rated tanks. The use of VP-1? also suffers from a freezing point around 13 C that requires heating during cold periods. One of the goals for future trough systems is the use of heat-transfer fluids that can act as thermal storage media and that allow operating temperatures around 425 C combined with lower limits around 0 C. This paper presents an outline of our latest approach toward the development of such thermal storage fluids.

Moens, L.; Blake, D.

2005-01-01T23:59:59.000Z

223

RELAP5/MOD3 simulation of the loss of residual heat removal during midloop operation experiment conducted at the ROSA-IV/ Large Scale Test Facility  

E-Print Network (OSTI)

The modeling of the complex thermal hydraulics Of reactor systems involves the use Of experimental test systems as well as numerical codes. A simulation of the loss of residual heat removal (RHR) during midloop operations was performed using the RELAP5/MOD3 thermal hydraulic code. The experiment was conducted at the Rig of Safety Assessment (ROSA)-IV/ Large Scale Test Facility (LSTF). The experiment involved a 5% cold leg break along with the loss of the RHR system-The transient was simulated for 3040 seconds. The ROSA-1-V/]LsTF is one of the largest test facilities in the world and is located in Japan. It is a volumetrically scaled (1/48) full height, two loop model of a Westinghouse four loop pressurized water reactor (PWR). The facility consists of pressure vessel, two symmetric loops, a pressurizer and a full emergency core cooling system (ECCS) system. The transient was run on the CRAY-YMP supercomputer at Texas A&M university. Core boiling and primary pressurization followed the initiation of the transient. The time to core boiling was overpredicted. Almost all Primary parameters were predicted well until the occurrence of the loop seal clearing (LSC) at 2400 seconds. The secondary side temperatures were in good agreement with the experimental data until the LSC. Following the LSC, the steam condensation in the tubes was not calculated. This resulted in the overprediction of primary pressures after the LSC. Also, the temperatures in the hot and the cold legs were overpredicted. Because there was no significant condensation in the U-tubes, the core remained uncovered. Moreover, the LSC did not recover. Consequently, secondary side temperatures were underpredicted after the LSC. This indicated the deficiency of the condensation model. The core temperature excursion at the time of the LSC was not predicted, though there was good agreement between the experimental and calculated data for the rest of the transient. Severe oscillations were calculated throughout the course of the transient. Overall, there was reasonable qualitative agreement between the measured and the calculated data.

Banerjee, Sibashis Sanatkumar

1994-01-01T23:59:59.000Z

224

Dehumidification Performance of Air Conditioning Systems in Supermarkets: Field Demonstration with Heat Pipe Heat Exchangers in Delchamps Supermarket, Gulf Breeze, Florida  

Science Conference Proceedings (OSTI)

Lower humidity in supermarkets translates to reduced operational cost from refrigeration equipment. A demonstration project at a Florida supermarket showed that use of a heat pipe heat exchanger (HPHX) improved the HVAC system's dehumidification performance; but lower airflow rates, with or without an HPHX, also provided significant dehumidification enhancements.

1996-07-27T23:59:59.000Z

225

Method of measuring heat influx of a cryogenic transfer system  

DOE Patents (OSTI)

A method is provided for measuring the heat influx of a cryogenic transfer system. A gaseous phase of the cryogen used during normal operation of the system is passed through the system. The gaseous cryogen at the inlet to the system is tempered to duplicate the normal operating temperature of the system inlet. The temperature and mass flow rate of the gaseous cryogen is measured at the outlet of the system, and the heat capacity of the cryogen is determined. The heat influx of the system is then determined from known thermodynamic relationships.

Niemann, Ralph C. (Downers Grove, IL); Zelipsky, Steven A. (Tinley Park, IL); Rezmer, Ronald R. (Lisle, IL); Smelser, Peter (Bruner, MO)

1981-01-01T23:59:59.000Z

226

Industrial Waste Heat Recovery Using Heat Pipes  

E-Print Network (OSTI)

For almost a decade now, heat pipes with secondary finned surfaces have been utilized in counter flow heat exchangers to recover sensible energy from industrial exhaust gases. Over 3,000 such heat exchangers are now in service, recovering an estimated energy equivalent of nearly 1.1 million barrels of oil annually. Energy recovered by these units has been used to either preheat process supply air or to heat plant comfort make-up air. Heat pipe heat exchangers have been applied to an ever-expanding variety of industrial processes. One notable application in recent years has been for combustion airs preheat of fired heaters in petroleum refineries and petrochemical plants. Another recent development has been a waste heat recovery boiler using heat pipes. This device has a number of advantageous features. Field operational experience of several units in service has been excellent.

Ruch, M. A.

1981-01-01T23:59:59.000Z

227

Geothermal heating for Caliente, Nevada  

DOE Green Energy (OSTI)

Utilization of geothermal resources in the town of Caliente, Nevada (population 600) has been the objective of two grants. The first grant was awarded to Ferg Wallis, part-owner and operator of the Agua Caliente Trailer Park, to assess the potential of hot geothermal water for heating the 53 trailers in his park. The results from test wells indicate sustainable temperatures of 140/sup 0/ to 160/sup 0/F. Three wells were drilled to supply all 53 trailers with domestic hot water heating, 11 trailers with space heating and hot water for the laundry from the geothermal resource. System payback in terms of energy cost-savings is estimated at less than two years. The second grant was awarded to Grover C. Dils Medical Center in Caliente to drill a geothermal well and pipe the hot water through a heat exchanger to preheat air for space heating. This geothermal preheater served to convert the existing forced air electric furnace to a booster system. It is estimated that the hospital will save an average of $5300 in electric bills per year, at the current rate of $.0275/KWH. This represents a payback of approximately two years. Subsequent studies on the geothermal resource base in Caliente and on the economics of district heating indicate that geothermal may represent the most effective supply of energy for Caliente. Two of these studies are included as appendices.

Wallis, F.; Schaper, J.

1981-02-01T23:59:59.000Z

228

Heat pipe array heat exchanger  

DOE Patents (OSTI)

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

Reimann, Robert C. (Lafayette, NY)

1987-08-25T23:59:59.000Z

229

Heat transfer system  

DOE Patents (OSTI)

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

Not Available

1980-03-07T23:59:59.000Z

230

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

231

Data Center Rating Infrastructure Rating Development  

NLE Websites -- All DOE Office Websites (Extended Search)

in Portfolio Manager on June 7, 2010. The questions below are designed to help data center owners and operators better understand the rating and benchmark their buildings in...

232

Heat pipe technology quarterly literature review. Volume 1, Number 3  

SciTech Connect

A bibliography containing 110 citations is presented. The citations are arranged in five sections on general information on heat pipes, heat pipe applications, heat pipe theory, heat pipe design, development, and fabrication, and heat pipe testing and operation.

Srinivasan, R.; Gonzales, R.W. (eds.)

1983-01-01T23:59:59.000Z

233

Modeling of wire-on-tube heat exchangers using finite element method  

Science Conference Proceedings (OSTI)

Wire-on-tube heat exchangers are analysed under normal operating conditions (free convection) using finite element method. Galerkin's weighted residual method is used to minimise the errors. The effects of ambient temperatures and mass flow rates of ... Keywords: finite element method, free convection, phase change, wire on-tube heat exchangers

G. A. Quadir; G. M. Krishnan; K. N. Seetharamu

2002-03-01T23:59:59.000Z

234

Customer Sited Combined Heat and Power on Maui: A Case Study  

Science Conference Proceedings (OSTI)

This report documents the experience of Maui Electric Company (MECO) in developing and operating a 150 kW combined heat and power (CHP) project at a resort on Maui. Tests conducted during the project evaluated the heat rate and performance of the packaged CHP system, which had been originally designed for natural gas fueling but was fueled by commercial propane in this application.

2005-02-14T23:59:59.000Z

235

ION CYCLOTRON RESONANCE HEATING IN A TOROIDAL OCTUPOLE J. C. Sprott and J. D. Barter  

E-Print Network (OSTI)

steady state ion temperature calculated from the theoretical heating rate S and charge exchange losses be achieved with ohmic heating alone. Many of the Tokamak-related problems can be studied on toroidal operation except for a modulation of the plasma potential of '" 100 volts at the rf frequency and a high

Sprott, Julien Clinton

236

Heat pump having improved defrost system  

DOE Patents (OSTI)

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

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

1998-12-08T23:59:59.000Z

237

Heat pump having improved defrost system  

DOE Patents (OSTI)

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

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

1998-01-01T23:59:59.000Z

238

GEOCITY: a computer code for calculating costs of district heating using geothermal resources  

DOE Green Energy (OSTI)

GEOCITY is a computer simulation model developed to study the economics of district heating using geothermal energy. GEOCITY calculates the cost of district heating based on climate, population, resource characteristics, and financing conditions. The principal input variables are minimum temperature, heating degree days, population size and density, resource temperature and distance from load center, and the interest rate. From this input data the model designs the transmission and district heating systems. From this design, GEOCITY calculates the capital and operating costs for the entire system, including the production and disposal of the geothermal water. GEOCITY consists of two major submodels: the geothermal reservoir model and the distribution system model. The distribution system model calculates the cost of heat by simulating the design and the operation of the district heating system. The reservoir model calculates the cost of energy by simulating the discovery, development and operation of a geothermal resource and the transmission of this energy to a distribution center.

McDonald, C.L.; Bloomster, C.H.; Schulte, S.C.

1977-02-01T23:59:59.000Z

239

Interface Heat Transfer Effects for Solidification Processes  

Science Conference Proceedings (OSTI)

The solidification rate of a casting is governed by the rate of heat extraction, which in turn is dominated by the rate of heat transfer across the casting-mold ...

240

Capture of Heat Energy from Diesel Engine Exhaust  

DOE Green Energy (OSTI)

Diesel generators produce waste heat as well as electrical power. About one-third of the fuel energy is released from the exhaust manifolds of the diesel engines and normally is not captured for useful applications. This project studied different waste heat applications that may effectively use the heat released from exhaust of Alaskan village diesel generators, selected the most desirable application, designed and fabricated a prototype for performance measurements, and evaluated the feasibility and economic impact of the selected application. Exhaust flow rate, composition, and temperature may affect the heat recovery system design and the amount of heat that is recoverable. In comparison with the other two parameters, the effect of exhaust composition may be less important due to the large air/fuel ratio for diesel engines. This project also compared heat content and qualities (i.e., temperatures) of exhaust for three types of fuel: conventional diesel, a synthetic diesel, and conventional diesel with a small amount of hydrogen. Another task of this project was the development of a computer-aided design tool for the economic analysis of selected exhaust heat recovery applications to any Alaskan village diesel generator set. The exhaust heat recovery application selected from this study was for heating. An exhaust heat recovery system was fabricated, and 350 hours of testing was conducted. Based on testing data, the exhaust heat recovery heating system showed insignificant effects on engine performance and maintenance requirements. From measurements, it was determined that the amount of heat recovered from the system was about 50% of the heat energy contained in the exhaust (heat contained in exhaust was evaluated based on environment temperature). The estimated payback time for 100% use of recovered heat would be less than 3 years at a fuel price of $3.50 per gallon, an interest rate of 10%, and an engine operation of 8 hours per day. Based on experimental data, the synthetic fuel contained slightly less heat energy and fewer emissions. Test results obtained from adding different levels of a small amount of hydrogen into the intake manifold of a diesel-operated engine showed no effect on exhaust heat content. In other words, both synthetic fuel and conventional diesel with a small amount of hydrogen may not have a significant enough effect on the amount of recoverable heat and its feasibility. An economic analysis computer program was developed on Visual Basic for Application in Microsoft Excel. The program was developed to be user friendly, to accept different levels of input data, and to expand for other heat recovery applications (i.e., power, desalination, etc.) by adding into the program the simulation subroutines of the desired applications. The developed program has been validated using experimental data.

Chuen-Sen Lin

2008-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "operating heat rate" 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

Quantifying Energy Savings by Improving Boiler Operation  

E-Print Network (OSTI)

On/off operation and excess combustion air reduce boiler energy efficiency. This paper presents methods to quantify energy savings from switching to modulation control mode and reducing excess air in natural gas fired boilers. The methods include calculation of combustion temperature, calculation of the relationship between internal convection coefficient and gas flow rate, and calculation of overall heat transfer assuming a parallel-flow heat exchanger model. The method for estimating savings from changing from on/off to modulation control accounts for purge and drift losses through the boiler and the improved heat transfer within the boiler due to the reduced combustion gas flow rate. The method for estimating savings from reducing excess combustion air accounts for the increased combustion temperature, reduced internal convection coefficient and increased residence time of combustion gasses in the boiler. Measured boiler data are used to demonstrate the accuracy of the methods.

Carpenter, K.; Kissock, J. K.

2005-01-01T23:59:59.000Z

242

Absorption heat pump system  

DOE Patents (OSTI)

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

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

1984-01-01T23:59:59.000Z

243

FEMP--Geothermal Heat Pumps  

NLE Websites -- All DOE Office Websites (Extended Search)

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...

244

Ground Source Heat Pump Sub-Slab Heat Exchange Loop Performance in a Cold Climate  

SciTech Connect

This report presents a cold-climate project that examines an alternative approach to ground source heat pump (GSHP) ground loop design. The innovative ground loop design is an attempt to reduce the installed cost of the ground loop heat exchange portion of the system by containing the entire ground loop within the excavated location beneath the basement slab. Prior to the installation and operation of the sub-slab heat exchanger, energy modeling using TRNSYS software and concurrent design efforts were performed to determine the size and orientation of the system. One key parameter in the design is the installation of the GSHP in a low-load home, which considerably reduces the needed capacity of the ground loop heat exchanger. This report analyzes data from two cooling seasons and one heating season. Upon completion of the monitoring phase, measurements revealed that the initial TRNSYS simulated horizontal sub-slab ground loop heat exchanger fluid temperatures and heat transfer rates differed from the measured values. To determine the cause of this discrepancy, an updated model was developed utilizing a new TRNSYS subroutine for simulating sub-slab heat exchangers. Measurements of fluid temperature, soil temperature, and heat transfer were used to validate the updated model.

Mittereder, N.; Poerschke, A.

2013-11-01T23:59:59.000Z

245

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 compared. Heat transfer ...

Ruleman, Karlen E. (Karlen Elizabeth)

2009-01-01T23:59:59.000Z

246

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

247

Subject: Changes to the 2001 NCEP Operational MRF/AVN  

E-Print Network (OSTI)

on Sundqvist et al.(1989). The precipitation rate P is parameterized following Zhao and Carr (1997) for ice with respect to water phase or ice phase depending on the temperature. Unlike the operational model, the new changes were in parameterization of cloud material, modification of the radiation heat loss from clouds

248

Heat pump apparatus  

DOE Patents (OSTI)

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

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

1983-01-01T23:59:59.000Z

249

CONTROL SYSTEM FOR SOLAR HEATING and COOLING  

E-Print Network (OSTI)

l U CONTROL SYSTEM FOR SOLAR HEATING AND COOLING* M.Wahlig,be capable of operating solar heating and cooling systemsand now transferred to ERDA, on solar heating and cooling of

Dols, C.

2010-01-01T23:59:59.000Z

250

Radiant Heating  

Energy.gov (U.S. Department of Energy (DOE))

Radiant heating systems involve supplying heat directly to the floor or to panels in the walls or ceiling of a house. The systems depend largely on radiant heat transfer: the delivery of heat...

251

Heat pump with freeze-up prevention  

DOE Patents (OSTI)

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

Ecker, Amir L. (Dallas, TX)

1981-01-01T23:59:59.000Z

252

Enhancement of heat transfer for ground source heat pump systems.  

E-Print Network (OSTI)

??Uptake of geothermal heat pump (GSHP) systems has been slow in some parts of the world due to the unpredictable operational performance, large installation space… (more)

Mori, Hiromi

2010-01-01T23:59:59.000Z

253

Tips: Heat Pumps | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Heat Pumps Heat Pumps Tips: Heat Pumps June 24, 2013 - 5:48pm Addthis Heat pumps can be a cost-effective choice in moderate climates, especially if you heat your home with electricity. Heat pumps can be a cost-effective choice in moderate climates, especially if you heat your home with electricity. Heat pumps are the most efficient form of electric heating in moderate climates. Because they move heat rather than generate heat, heat pumps can provide equivalent space conditioning at as little as one quarter of the cost of operating conventional heating or cooling appliances. A heat pump does double duty as a central air conditioner by collecting the heat inside your house and pumping it outside. There are three types of heat pumps: air-to-air, water source, and geothermal. They collect heat from the air, water, or ground outside your

254

Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for Concentrating Solar Power Plants  

Science Conference Proceedings (OSTI)

A key technological issue facing the success of future Concentrating Solar Thermal Power (CSP) plants is creating an economical Thermal Energy Storage (TES) system. Current TES systems use either sensible heat in fluids such as oil, or molten salts, or use thermal stratification in a dual-media consisting of a solid and a heat-transfer fluid. However, utilizing the heat of fusion in inorganic molten salt mixtures in addition to sensible heat , as in a Phase change material (PCM)-based TES, can significantly increase the energy density of storage requiring less salt and smaller containers. A major issue that is preventing the commercial use of PCM-based TES is that it is difficult to discharge the latent heat stored in the PCM melt. This is because when heat is extracted, the melt solidifies onto the heat exchanger surface decreasing the heat transfer. Even a few millimeters of thickness of solid material on heat transfer surface results in a large drop in heat transfer due to the low thermal conductivity of solid PCM. Thus, to maintain the desired heat rate, the heat exchange area must be large which increases cost. This project demonstrated that the heat transfer coefficient can be increase ten-fold by using forced convection by pumping a hyper-eutectic salt mixture over specially coated heat exchanger tubes. However,only 15% of the latent heat is used against a goal of 40% resulting in a projected cost savings of only 17% against a goal of 30%. Based on the failure mode effect analysis and experience with pumping salt at near freezing point significant care must be used during operation which can increase the operating costs. Therefore, we conclude the savings are marginal to justify using this concept for PCM-TES over a two-tank TES. The report documents the specialty coatings, the composition and morphology of hypereutectic salt mixtures and the results from the experiment conducted with the active heat exchanger along with the lessons learnt during experimentation.

Mathur, Anoop [Terrafore Inc.] [Terrafore Inc.

2013-08-14T23:59:59.000Z

255

Heat pipe technology issues  

SciTech Connect

Critical high temperature, high power applications in space nuclear power designs are near the current state of the art of heat pipe technology in terms of power density, operating temperature, and lifetime. Recent heat pipe development work at Los Alamos National Laboratory has involved performance testing of typical space reactor heat pipe designs to power levels in excess of 19 kW/cm/sup 2/ axially and 300 W/cm/sup 2/ radially at temperatures in the 1400 to 1500 K range. Operation at conditions in the 10 kW/cm/sup 2/ range has been sustained for periods of up to 1000 hours without evidence of performance degradation. The effective length for heat transport in these heat pipes was from 1.0 to 1.5 M. Materials used were molybdenum alloys with lithium employed as the heat pipe operating fluid. Shorter, somewhat lower power, molybdenum heat pipes have been life tested at Los Alamos for periods of greater than 25,000 hours at 1700 K with lithium and 20,000 hours at 1500/sup 0/K with sodium. These life test demonstrations and the attendant performance limit investigations provide an experimental basis for heat pipe application in space reactor design and represent the current state-of-the-art of high temperature heat pipe technology.

Merrigan, M.A.

1984-04-01T23:59:59.000Z

256

THERMAL STUDY OF THE DIII-D MACHINE HEAT REMOVAL CAPACITY  

Science Conference Proceedings (OSTI)

OAK-B135 With each plasma shot, the DIII-D tokamak dissipates 0.5 to 1.0 GJ of energy. Plasma shots may occur as frequently as every ten minutes, and the energy is removed in the form of heat by a cooling water system. to remove heat from the machine, cooling water circulates through each major heat source. These sources include the power supplies, motor/generator, rf current drives, neutral beam power supplies, magnetic field coils, and vacuum vessel. The cooling water system consists of isolated primary and secondary cooling loops separated by intermediate heat exchangers. As future DIII-D plans include operation during summer months and longer pulse duration, the cooling system's overall heat removal capability and performance efficiency must be assessed. Temperature and flow data from around the DIII-D facility are collected by a programmable logic controller (PLC); the data are used to analyze the heat generating sources, the heat transfer rate to intermediate heat exchangers, and the ultimate heat rejection to the environment via the cooling towers. A comparison of the original DIII-D machine design versus the actual performance determines the margin of heat removal capacity. projections of the heat removal rate for various longer plasma shots are made. Improvements in design and/or operational procedure will be necessary to attain the desired pulse duration.

YIP,H; ADERSON,P.M; HOLTROP,K.L; HARRISON,S

2003-10-01T23:59:59.000Z

257

Systematic Method for Evaluating Extraction and Injection Flow Rates for 100-KR-4 and 100-HR-3 Groundwater Operable Unit Pump-and-Treat Interim Actions for Hydraulic Containment  

Science Conference Proceedings (OSTI)

This document describes a systematic method to develop flow rate recommendations for Pump-and-Treat (P&T) extraction and injection wells in 100-KR-4 and 100-HR-3 Groundwater Operable Units (OU) of the Hanford Site. Flow rate recommendations are developed as part of ongoing performance monitoring and remedy optimization of the P&T interim actions to develop hydraulic contairnnent of the dissolved chromium plume in groundwater and protect the Columbia River from further discharges of groundwater from inland. This document details the methodology and data required to infer the influence of individual wells near the shoreline on hydraulic containment and river protection and develop flow rate recommendations to improve system performance and mitigate potential shortcomings of the system configuration in place.

Spiliotopoulos, Alexandros A.

2013-03-20T23:59:59.000Z

258

System for measuring the effect of fouling and corrosion on heat transfer under simulated OTEC conditions. [HTAU and LABTTF codes  

DOE Green Energy (OSTI)

A complete system designed to measure, with high precision, changes in heat transfer rates due to fouling and corrosion of simulated heat exchanger tubes, at sea and under OTEC conditions is described. All aspects of the system are described in detail, including theory, mechanical design, electronics design, assembly procedures, test and calibration, operating procedures, laboratory results, field results, and data analysis programs.

Fetkovich, J.G.

1976-12-01T23:59:59.000Z

259

Switchable heat pipe assembly  

SciTech Connect

The heat pipe assembly is formed into an H-shape or a Y-shape. The H-shaped configuration comprises two heat pipes, each having condenser and evaporator sections with wicking therein coupled by a tube with wick at their evaporator sections. The Y-shaped configuration utilizes a common evaporator section in place of the two evaporator sections of the H-shaped configuration. In both configurations, the connection between the vapor spaces of the two heat pipes equalizes vapor pressure within the heat pipes. Although both heat pipes have wicks, they have sufficient fluid only to saturate a single pipe. If heat is applied to the condenser section of one of the pipes, this heat pipe becomes inoperative since all the fluid is transferred to the second pipe which can operate with a lower thermal load.

Sun, T.H.; Basiulis, A.

1977-02-15T23:59:59.000Z

260

Field Performance of Heat Recovery Chillers and Heat Recovery Heat Pumps  

Science Conference Proceedings (OSTI)

Heat recovery chillers and heat recovery heat pumps operate at high efficiency and excellent economy by simultaneously providing both heating and cooling. Although this technology has been in use for more than thirty years and all major chiller manufacturers offer heat recovery models, applications are not yet widespread. One of the barriers to using this technology is the lack of measured performance information on the devices. This project was undertaken to identify and summarize existing sources of pe...

1994-05-18T23:59:59.000Z

Note: This page contains sample records for the topic "operating heat rate" 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

SSA Operations  

NLE Websites -- All DOE Office Websites (Extended Search)

Area Operations (SSA-Ops) Area Operations (SSA-Ops) "BOREAS Ops" was located at the Snodrifters Lodge, in Candle Lake, Saskatchewan. Radiosonde balloon launch at Ops The NASA Helicopter lands at Ops A meeting at the Snodrifter's Lodge Release of a radiosonde at the SSA operations center in Candle Lake. Back to the BOREAS Photo Page Index Other Sites: NSA Photos ||NSA-BP Photos | NSA-Fen Photos | NSA-OA Photos | NSA-OBS Photos | NSA-OJP Photos | NSA-UBS Photos | NSA-YJP Photos | NSA-Ops Photos SSA Photos || SSA-Airport Photos | SSA-Fen Photos | SSA-Mix Photos | SSA-OA Photos | SSA-OBS Photos | SSA-OJP Photos | SSA-YA Photos | SSA-YJP Photos | SSA-Ops Photos | ORNL DAAC Home || ORNL Home || NASA || Privacy, Security, Notices || Data Citation || Rate Us || Help | User Services - Tel: +1 (865) 241-3952 or E-mail: uso@daac.ornl.gov

262

BOREAS Operations  

NLE Websites -- All DOE Office Websites (Extended Search)

Study Area Operations/Thompson Airport (NSA-Ops) Study Area Operations/Thompson Airport (NSA-Ops) NSA Operations (NSA-Ops) The Keewatin Air Hanger: site of BOREAS Ops 1994 Dr. Piers Sellers working in Ops, 1994 BOREAS "Air Force" The NASA C-130 The University of Wyoming King Air The NASA Helicopter The NRC Twin Otter The NCAR Electra The Ontario Chieftain Back to the BOREAS Photo Page Index Other Sites: NSA Photos ||NSA-BP Photos | NSA-Fen Photos | NSA-OA Photos | NSA-OBS Photos | NSA-OJP Photos | NSA-UBS Photos | NSA-YJP Photos | NSA-Ops Photos SSA Photos || SSA-Airport Photos | SSA-Fen Photos | SSA-Mix Photos | SSA-OA Photos | SSA-OBS Photos | SSA-OJP Photos | SSA-YA Photos | SSA-YJP Photos | SSA-Ops Photos | ORNL DAAC Home || ORNL Home || NASA || Privacy, Security, Notices || Data Citation || Rate Us || Help |

263

FEMP--Geothermal Heat Pumps  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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.

264

Experimental and theoretical investigation of operational and survivability issues in thermal radiators for thermionic space nuclear power systems. Final report  

SciTech Connect

Heat pipes are a promising candidate for spacecraft radiators. This report describes a program designed to investigate the mass migration phenomenon in heat pipes. The program involved experiments to observe and measure the mass migration rates in both high and low operating temperature heat pipes. The low-temperature experiments were intended to simulate the operation of high-temperature, liquid metal heat pipes. Octadecane was the selected low-temperature working fluid. It is a paraffin and exhibits some of the characteristics of liquid metal working fluids. Sodium was the working fluid used in the high temperature experiment. A one-dimensional compressible flow model was developed for describing the hydrodynamics of rarefied vapor flow in heat pipe condensers. This model was compared with experimental data for the low-temperature octadecane heat pipes and the high-temperature sodium heat pipe. The model was found to satisfactorily predict the temperature profiles and location of freeze-fronts for the low-temperature heat pipes. Mass migration rate predictions using the model were satisfactory for the low-temperature heat pipes as well. However, the mass migration prediction for the high-temperature, sodium heat pipe was not in agreement with experimental data. An analytical model which accounts for property variations in the radial as well as longitudinal directions is recommended. A one-dimensional model was unsatisfactory for predicting mass migration rates in liquid metal heat pipes.

Keddy, M.D.

1994-03-15T23:59:59.000Z

265

Heat and mass exchanger  

Science Conference Proceedings (OSTI)

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

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

2011-06-28T23:59:59.000Z

266

TRANSPARENT HEAT MIRRORS FOR PASSIVE SOLAR HEATING APPLICATIONS  

E-Print Network (OSTI)

deposition rates and production costs were reviewed todiscussion of heat mirror production cost Most of our effortcoating plastic film. Production costs for coating glass

Selkowitz, S.

2011-01-01T23:59:59.000Z

267

Environmental Impact Statement (EIS) for the Transfer of the Heat Source / Radioisotope Themoelectric Generator Assembly and Test Operations From the Mound Site  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

031 031 Federal Register / Vol. 63, No. 191 / Friday, October 2, 1998 / Notices SUPPLEMENTARY INFORMATION: The package listing contains the following information: (1) Title of the information collection package; (2) current OMB control number; (3) type of respondents; (4) estimated number of responses annually; (5) estimated total burden hours, annually, including recordkeeping hours required to provide the information; (6) purpose; and (7) number of collections. Package Title: Legal. Current OMB No.: 1910-0800. Type of Respondents: DOE management and operating contractors, and offsite contractors. Estimated Number of Responses: 2,719. Estimated Total Burden Hours: 21,052. Purpose: This information is required by the Department to ensure that legal resources and requirements are

268

Waste Heat Reduction and Recovery for Improving Furnace Efficiency, Productivity and Emissions Performance: A BestPractices Process Heating Technical Brief  

DOE Green Energy (OSTI)

This technical brief is a guide to help plant operators reduce waste heat losses associated with process heating equipment.

Not Available

2004-11-01T23:59:59.000Z

269

Heat pipe development status  

SciTech Connect

Test heat pipes have been operated in the 1400 K to 1700 K range for periods in excess of 20,000 hours with the objective of understanding and controlling corrosion and failure mechanisms. The results of a post test analysis of one of these heat pipes that was operated for 25,216 hours at 1700 K are reviewed and the implications for heat pipe lifetime discussed. An in-process report of an investigation of transient heat pipe behavior is presented. This investigation is being conducted as a result of restart problems encountered during life test of a 2 m. radiation cooled heat pipe. The results of a series of shut-down tests from power and temperature are given and probable causes of the restart problem discussed.

Merrigan, M.A.

1984-01-01T23:59:59.000Z

270

Fundamental heat transfer experiments of heat pipes for turbine cooling  

SciTech Connect

Fundamental heat transfer experiments were carried out for three kinds of heat pipes that may be applied to turbine cooling in future aero-engines. In the turbine cooling system with a heat pipe, heat transfer rate and start-up time of the heat pipe are the most important performance criteria to evaluate and compare with conventional cooling methods. Three heat pipes are considered, called heat pipe A, B, and C, respectively. All heat pipes have a stainless steel shell and nickel sintered powder metal wick. Sodium (Na) was the working fluid for heat pipes A and B; heat pipe C used eutectic sodium-potassium (NaK). Heat pipes B and C included noncondensible gas for rapid start-up. There were fins on the cooling section of heat pipes. In the experiments, an infrared image furnace supplied heat to the heat pipe simulating turbine blade surface conditions. In the results, heat pipe B demonstrated the highest heat flux of 17 to 20 W/cm{sup 2}. The start-up time was about 6 minutes for heat pipe B and about 6 minutes for heat pipe A. Thus, adding noncondensible gas effectively reduced start-up time. Although NaK is a liquid phase at room temperature, the start-up time of heat pipe C (about 7 to 8 minutes) was not shorter than the heat pipe B. The effect of a gravitational force on heat pipe performance was also estimated by inclining the heat pipe at an angle of 90 deg. There was no significant gravitational dependence on heat transport for heat pipes including noncondensible gas.

Yamawaki, S. [Ishikawajima-Harima Heavy Industries Co., Ltd., Tokyo (Japan); Yoshida, T.; Taki, M.; Mimura, F. [National Aerospace Lab., Tokyo (Japan)

1998-07-01T23:59:59.000Z

271

Method of measuring heat influx of a cryogenic transfer system. [Patent application  

DOE Patents (OSTI)

A method is provided for measuring the heat influx of a cryogenic transfer system. A gaseous phase of the cryogen used during normal operation of the system is passed through the system. The gaseous cryogen at the inlet to the system is tempered to duplicate the normal operating temperature of the system inlet. The temperature and mass flow rate of the gaseous cryogen is measured at the outlet of the system, and the heat capacity of the cryogen is determined. The heat influx of the system is then determined from known thermodynamic relationships.

Niemann, R.C.; Zelipsky, S.A.; Rezmer, R.R.; Smelser, P.

1980-10-29T23:59:59.000Z

272

Heating Alloys  

Science Conference Proceedings (OSTI)

...are used in many varied applications--from small household appliances to large industrial process heating systems and furnaces. In appliances or industrial process heating, the heating elements are usually either open

273

Infrared Thermography applied to measurement of Heat transfer coefficient of water in a pipe heated by Joule effect  

E-Print Network (OSTI)

. Internal sources of heat are due to convection from flow of the heat transfer fluid through the pipes. Heat (material, diameter, spacing, and burial depth), (4) system flow rates, (5) heat transfer fluid properties · heat transfer fluid = 42% propylene glycol @ a flow rate of 350 gpm · heat pump model = Water Furnace

274

Passive heat transfer means for nuclear reactors  

DOE Patents (OSTI)

An improved passive cooling arrangement is disclosed for maintaining adjacent or related components of a nuclear reactor within specified temperature differences. Specifically, heat pipes are operatively interposed between the components, with the vaporizing section of the heat pipe proximate the hot component operable to cool it and the primary condensing section of the heat pipe proximate the other and cooler component operable to heat it. Each heat pipe further has a secondary condensing section that is located outwardly beyond the reactor confinement and in a secondary heat sink, such as air ambient the containment, that is cooler than the other reactor component. Means such as shrouding normally isolated the secondary condensing section from effective heat transfer with the heat sink, but a sensor responds to overheat conditions of the reactor to open the shrouding, which thereby increases the cooling capacity of the heat pipe. By having many such heat pipes, an emergency passive cooling system is defined that is operative without electrical power.

Burelbach, James P. (Glen Ellyn, IL)

1984-01-01T23:59:59.000Z

275

Heating Systems  

Energy.gov (U.S. Department of Energy (DOE))

A variety of heating technologies are available today. In addition to heat pumps, which are discussed separately, many homes and buildings use the following approaches:

276

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

277

ASSESSMENT OF COMBINED HEAT AND POWER SYSTEM "PREMIUM POWER" APPLICATIONS IN CALIFORNIA  

E-Print Network (OSTI)

heat and power; distributed generation; premium powerand operation of distributed generation, combined heat andcost combination of distributed generation technologies that

Norwood, Zack

2010-01-01T23:59:59.000Z

278

NGNP Process Heat Utilization: Liquid Metal Phase Change Heat Exchanger  

DOE Green Energy (OSTI)

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

Piyush Sabharwall; Mike Patterson; Vivek Utgikar; Fred Gunnerson

2008-09-01T23:59:59.000Z

279

Simulation and analysis of district-heating and -cooling systems  

DOE Green Energy (OSTI)

A computer simulation model, GEOCITY, was developed to study the design and economics of district heating and cooling systems. GEOCITY calculates the cost of district heating based on climate, population, energy source, and financing conditions. The principal input variables are minimum temperature, heating degree-days, population size and density, energy supply temperature and distance from load center, and the interest rate. For district cooling, maximum temperature and cooling degree-hours are required. From this input data the model designs the fluid transport and district heating systems. From this design, GEOCITY calculates the capital and operating costs for the entire system. GEOCITY was originally developed to simulate geothermal district heating systems and thus, in addition to the fluid transport and distribution models, it includes a reservoir model to simulate the production of geothermal energy from geothermal reservoirs. The reservoir model can be adapted to simulate the supply of hot water from any other energy source. GEOCITY has been used extensively and has been validated against other design and cost studies. GEOCITY designs the fluid transport and distribution facilities and then calculates the capital and operating costs for the entire system. GEOCITY can simulate nearly any financial and tax structure through varying the rates of return on equity and debt, the debt-equity ratios, and tax rates. Both private and municipal utility systems can be simulated.

Bloomster, C.H.; Fassbender, L.L.

1983-03-01T23:59:59.000Z

280

The Broadband Heating Rate Profile (BBHRP) VAP  

NLE Websites -- All DOE Office Websites (Extended Search)

Ellingson Florida State University Tallahassee, Florida M. H. Zhang State University of New York at Albany Albany, New York Stony Brook R. A. Ferrare National Aeronautics and...

Note: This page contains sample records for the topic "operating heat rate" 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

Nitrogen heat pipe for cryocooler thermal shunt  

SciTech Connect

A nitrogen heat pipe was designed, built and tested for the purpose of providing a thermal shunt between the two stages of a Gifford-McMahan (GM) cryocooler during cooldown. The nitrogen heat pipe has an operating temperature range between 63 and 123 K. While the heat pipe is in the temperature range during the system cooldown, it acts as a thermal shunt between the first and second stage of the cryocooler. The heat pipe increases the heat transfer to the first stage of the cryocooler, thereby reducing the cooldown time of the system. When the heat pipe temperature drops below the triple point, the nitrogen working fluid freezes, effectively stopping the heat pipe operation. A small heat leak between cryocooler stages remains because of axial conduction along the heat pipe wall. As long as the heat pipe remains below 63 K, the heat pipe remains inactive. Heat pipe performance limits were measured and the optimum fluid charge was determined.

Prenger, F.C.; Hill, D.D.; Daney, D.E.; Daugherty, M.A. [Los Alamos National Lab., NM (United States); Green, G.F.; Roth, E.W. [Naval Surface Warfare Center, Annapolis, MD (United States)

1995-09-01T23:59:59.000Z

282

Heat pipe transient response approximation.  

SciTech Connect

A simple and concise routine that approximates the response of an alkali metal heat pipe to changes in evaporator heat transfer rate is described. This analytically based routine is compared with data from a cylindrical heat pipe with a crescent-annular wick that undergoes gradual (quasi-steady) transitions through the viscous and condenser boundary heat transfer limits. The sonic heat transfer limit can also be incorporated into this routine for heat pipes with more closely coupled condensers. The advantages and obvious limitations of this approach are discussed. For reference, a source code listing for the approximation appears at the end of this paper.

Reid, R. S. (Robert Stowers)

2001-01-01T23:59:59.000Z

283

Ceramic heat pipes for high temperature heat removal  

SciTech Connect

Difficulties in finding metal or protected metal components that exhibit both strength and corrosion resistance at high temperature have severely restricted the application of effective heat recovery techniques to process heat furnaces. A potential method of overcoming this restriction is to use heat pipes fabricated from ceramic materials to construct counterflow recuperators. A development program has been initiated to demonstrate the technical and eventually the economical feasibility of ceramic heat pipes and ceramic heat pipe recuperators. The prime candidate for heat pipe construction is SiC. Closed-end tubes of this material have been prepared by chemical vapor deposition (CVD). These tubes were lined internally with tungsten by a subsequent CVD operation, partially filled with sodium, and sealed by brazing a tungsten lined SiC plug into the open-end with a palladium--cobalt alloy. Heat pipes constructed in this manner have been successfully operated in vacuum at temperatures of 1225/sup 0/K and in air at a temperature of 1125/sup 0/K. The heat source used initially for the air testing was an induction heated metallic sleeve in thermal contact with the test unit. Subsequent testing has shown that a silicon carbide heat pipe can be successfully operated with natural gas burners providing the input heat. Methods of fabricating and testing these devices are described.

Keddy, E.S.; Ranken, W.A.

1978-01-01T23:59:59.000Z

284

Waste Heat Recovery from Industrial Smelting Exhaust Gas  

Science Conference Proceedings (OSTI)

For a cost efficient capture of more valuable heat (higher exergy), heat exchangers should operate on the exhaust gases upstream of the gas treatment plants.

285

Heat Tint Effects on General Corrosion Resistance of Stainless Steels  

Science Conference Proceedings (OSTI)

The heat tint is usually created during a welding operation. The heat tint creates an oxide ... Reformer Inlet Hair-pin-pipe Weld Cracking · Remedy of Deficiencies

286

JGI - Operations  

NLE Websites -- All DOE Office Websites (Extended Search)

Operations The Operations Department sees to it that JGI has the best possible facilities and support, ensuring that its operations are conducted in accordance with the...

287

Power Operations  

NLE Websites -- All DOE Office Websites (Extended Search)

Power Operations Outage Coordination Standards of Conduct Transmission Planning You are here: SN Home page > Power Operations Power Operations Western's Sierra Nevada Region...

288

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

E-Print Network (OSTI)

An irreversible cycle model of a heat pump operating between two variable-temperature heat reservoirs is established and used to analyze the performance of the heat pump affected by heat resistances, heat leakage and internal dissipation of the working substance. The coefficient of performance of the heat pump is optimized for a given heating load. The characteristic curves of the coefficient of performance versus power input are generated. The influence of intake temperatures of heat reservoirs, thermal capacity of heat reservoirs, efficiency of heat exchangers, heat leak and internal irreversibilities on the performance of the system is discussed. The optimal ratio of the times spent on two processes of heat transfer to and from the working substance is determined. Some new results which are conducive to the optimal design and operation of real heat pump systems are obtained.

Huang, Y.; Sun, D.

2006-01-01T23:59:59.000Z

289

A Comparison of Mass Rate and Steam Quality Reductions to Optimize Steamflood Performance  

SciTech Connect

Many operators of steamdrive projects will reduce the heat injection rate as the project matures. The major benefit of this practice is to reduce the fuel costs and thus extend the economic life of the project. However, there is little industry consensus on whether the heat cuts should take the form of: (1) mass rate reductions while maintaining the same high steam quality, or (2) steam quality decreases while keeping the same mass rate. Through the use of a commercial three-phase, three-dimensional simulator, the oil recovery schedules obtained when reducing the injected steam mass rate or quality with time were compared under a variety of reservoir and operating conditions. The simulator input was validated for Kern River Field conditions by using the guidelines developed by Johnson, et at. (1989) for four steamflood projects in Kern River. The results indicate that for equivalent heat injection rates, decreasing the steam injection mass rate at a constant high quality will yield more economic oil than reducing the steam quality at a constant mass rate. This conclusion is confirmed by a sensitivity analysis which demonstrates the importance of the gravity drainage/steam zone expansion mechanism in a low-pressure, heavy oil steamflood with gravity segregation. Furthermore, the impact of discontinuous silts and nonuniform initial temperatures within the steamflood zone was studied, indicating again that a decreasing mass rate injection strategy is a superior operating practice.

Messner, Gregory L.

1999-08-09T23:59:59.000Z

290

Critical reaction rates in hypersonic combustion chemistry  

DOE Green Energy (OSTI)

High Mach number flight requires that the scramjet propulsion system operate at a relatively low static inlet pressure and a high inlet temperature. These two constraints can lead to extremely high temperatures in the combustor, yielding high densities of radical species and correspondingly poor chemical combustion efficiency. As the temperature drops in the nozzle expansion, recombination of these excess radicals can produce more product species, higher heat yield, and potentially more thrust. The extent to which the chemical efficiency can be enhanced in the nozzle expansion depends directly on the rate of the radical recombination reactions. A comprehensive assessment of the important chemical processes and an experimental validation of the critical rate parameters is therefore required if accurate predictions of scramjet performance are to be obtained. This report covers the identification of critical reactions, and the critical reaction rates in hypersonic combustion chemistry. 4 refs., 2 figs.

Oldenborg, R.C.; Harradine, D.M.; Loge, G.W.; Lyman, J.L.; Schott, G.L.; Winn, K.R.

1989-01-01T23:59:59.000Z

291

HEAT TRANSFER METHOD  

DOE Patents (OSTI)

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

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

1960-08-30T23:59:59.000Z

292

Geothermal direct contact heat exchange. Final report  

DOE Green Energy (OSTI)

A glass direct contact heat exchange column was operated in the laboratory. The column was operated at atmospheric pressure using hot water and normal hexane. Column internals testing included an empty column, sieve trays, disk-and-doughnut trays, and two types of packing. Operation was very smooth in all cases and the minimum temperature approaches varied from less than 1/sup 0/C for packing to 13/sup 0/C for the empty column. High heat transfer rates were obtained in all cases, however, columns should be sized on the basis of liquid and vapor traffic. The solubilities of hydrocarbons were determined for normal hexane, pentane and butane in water and sodium chloride and calcium chloride brines at various temperatures. The values seem to be internally consistent and salt content was found to depress hydrocarbon solubility. Laboratory stripping tests showed that gas stripping can be used to remove hydrocarbon from reject hot water from the direct contact heat exchange column. Although the gas volumes required are small, stripping gas requirements cannot be accurately predicted without testing. A computer program was used to study the effect of operating variables on the thermodynamic cycle efficiencies. Optimum efficiencies for the moderate brine conditions studied were obtained with isopentane as working fluid and relatively low operating pressure. A preliminary design for a 50 MWe plant was prepared and plant capital cost and operating cost were estimated. These costs were combined with previously developed brine production and power transmission costs to provide an estimate of the cost of delivered power for a geothermal field at Heber, California. A pilot plant program is described that would be suitable for continuing the investigation of the direct contact process in the field. The program includes a suggested schedule and the estimated cost.

Sims, A.V.

1977-06-10T23:59:59.000Z

293

Heat Conduction  

Science Conference Proceedings (OSTI)

Table 2   Differential equations for heat conduction in solids...conduction in solids General form with variable thermal properties General form with constant thermal properties General form, constant properties, without heat

294

Waste Heat Recovery Power Generation with WOWGen  

E-Print Network (OSTI)

WOW operates in the energy efficiency field- one of the fastest growing energy sectors in the world today. The two key products - WOWGen® and WOWClean® provide more energy at cheaper cost and lower emissions. •WOWGen® - Power Generation from Industrial Waste Heat •WOWClean® - Multi Pollutant emission control system. Current power generation technology uses only 35% of the energy in a fossil fuel and converts it to useful output. The remaining 65% is discharged into the environment as waste heat at temperatures ranging from 300°F to 1,200°F. This waste heat can be captured using the WOWGen® technology and turned into electricity. This efficiency is up to twice the rate of competing technologies. Compelling economics and current environmental policy are stimulating industry interest. WOWGen® power plants can generate between 1 - 25 MW of electricity. Project payback is between two to five years with IRR of 15% 30%. Nearly anywhere industrial waste heat is present, the WOW products can be applied. Beneficial applications of heat recovery power generation can be found in Industry (e.g. steel, glass, cement, lime, pulp and paper, refining and petrochemicals), Power Generation (CHP, biomass, biofuel, traditional fuels, gasifiers, diesel engines) and Natural Gas (pipeline compression stations, processing plants). Sources such as stack flue gases, steam, diesel exhaust, hot oil or combinations of sources can be used to generate power. WOWGen® can also be used with stand alone power plants burning fossil fuels or using renewable energy sources such as solar and biomass.

Romero, M.

2009-05-01T23:59:59.000Z

295

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

296

Heat exchanger  

DOE Patents (OSTI)

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

Daman, Ernest L. (Westfield, NJ); McCallister, Robert A. (Mountain Lakes, NJ)

1979-01-01T23:59:59.000Z

297

Solar heat pipe feedback turbogenerator  

SciTech Connect

The conversion of radiant heat to electricity by a heat pipe-turbogenerator combination is described. The heat pipe-tubogenerator assembly is suitably externally insulated, as by a vacuum shield, to prevent heat losses and heat is recovered from the condenser portion of the heat pipe and returned to the evaporator portions. An application of the generic invention is discussed which it is employed on wall or roof portions of a building and serves as at least a partial supporting structure for these. In another application the solar heat pipe feedback turbogenerator may be incorporated in or used with reflective means, such as reflective sheet material of large area positioned to direct solar radiation onto the evaporator section of the heat pipe. The reflective means may be changed in position to follow the sun to produce maximum power during operation.

Decker, B.J.

1978-10-24T23:59:59.000Z

298

Absorption-heat-pump system  

DOE Patents (OSTI)

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

Grossman, G.; Perez-Blanco, H.

1983-06-16T23:59:59.000Z

299

Magnetic refrigeration apparatus with heat pipes  

DOE Patents (OSTI)

A magnetic refrigerator operating in the 4 to 20 K range utilizes heat pipes to transfer heat to and from the magnetic material at the appropriate points during the material's movement. In one embodiment circular disks of magnetic material can be interleaved with the ends of the heat pipes. In another embodiment a mass of magnetic material reciprocatingly moves between the end of the heat pipe or pipes that transmits heat from the object of cooling to the magnetic material and the end of the heat pipe or pipes that transmits heat from the magnetic material to a heat sink.

Barclay, J.A.; Prenger, F.C. Jr.

1985-10-25T23:59:59.000Z

300

Magnetic refrigeration apparatus with heat pipes  

DOE Patents (OSTI)

A magnetic refrigerator operating in the 4 to 20 K range utilizes heat pipes to transfer heat to and from the magnetic material at the appropriate points during the material's movement. In one embodiment circular disks of magnetic material can be interleaved with the ends of the heat pipes. In another embodiment a mass of magnetic material reciprocatingly moves between the end of the heat pipe of pipes that transmits heat from the object of cooling to the magnetic material and the end of the heat pipe or pipes that transmits heat from the magnetic material to a heat sink.

Barclay, John A. (Los Alamos, NM); Prenger, Jr., F. Coyne (Madison, WI)

1987-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "operating heat rate" 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

Energy Basics: Heat Pump Water Heaters  

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

for optimum operation in either summer or winter. Homeowners primarily install geothermal heat pumps-which draw heat from the ground during the winter and from the indoor air...

302

Nonlinear thermomechanical finite-element modeling, analysis and characterization of multi-turn oscillating heat pipes .  

E-Print Network (OSTI)

??Oscillating heat pipes (OHPs) are promising heat dissipation devices for modern electronic systems due to their high heat transfer rate, simple construction and low manufacturing… (more)

Peng, Hao

2012-01-01T23:59:59.000Z

303

Microchannel Heat Exchangers with Carbon Dioxide  

Science Conference Proceedings (OSTI)

The objective of the present study was to determine the performance of CO{sub 2} microchannel evaporators and gas coolers in operational conditions representing those of residential heat pumps. A set of breadboard prototype microchannel evaporators and gas coolers was developed and tested. The refrigerant in the heat exchangers followed a counter cross-flow path with respect to the airflow direction. The test conditions corresponded to the typical operating conditions of residential heat pumps. In addition, a second set of commercial microchannel evaporators and gas coolers was tested for a less comprehensive range of operating conditions. The test results were reduced and a comprehensive data analysis, including comparison with the previous studies in this field, was performed. Capacity and pressure drop of the evaporator and gas cooler for the range of parameters studied were analyzed and are documented in this report. A gas cooler performance prediction model based on non-dimensional parameters was also developed and results are discussed as well. In addition, in the present study, experiments were conducted to evaluate capacities and pressure drops for sub-critical CO{sub 2} flow boiling and transcritical CO{sub 2} gas cooling in microchannel heat exchangers. An extensive review of the literature failed to indicate any previous systematic study in this area, suggesting a lack of fundamental understanding of the phenomena and a lack of comprehensive data that would quantify the performance potential of CO{sub 2} microchannel heat exchangers for the application at hand. All experimental tests were successfully conducted with an energy balance within {+-}3%. The only exceptions to this were experiments at very low saturation temperatures (-23 C), where energy balances were as high as 10%. In the case of evaporators, it was found that a lower saturation temperature (especially when moisture condensation occurs) improves the overall heat transfer coefficient significantly. However, under such conditions, air side pressure drop also increases when moisture condensation occurs. An increase in airflow rate also increases the overall heat transfer coefficient. Air side pressure drop mainly depends on airflow rate. For the gas cooler, a significant portion of the heat transfer occurred in the first heat exchanger module on the refrigerant inlet side. The temperature and pressure of CO{sub 2} significantly affect the heat transfer and fluid flow characteristics due to some important properties (such as specific heat, density, and viscosity). In the transcritical region, performance of CO{sub 2} strongly depends on the operating temperature and pressure. Semi-empirical models were developed for predictions of CO{sub 2} evaporator and gas cooler system capacities. The evaporator model introduced two new factors to account for the effects of air-side moisture condensate and refrigerant outlet superheat. The model agreed with the experimental results within {+-}13%. The gas cooler model, based on non-dimensional parameters, successfully predicted the experimental results within {+-}20%. Recommendations for future work on this project include redesigning headers and/or introducing flow mixers to avoid flow mal-distribution problems, devising new defrosting techniques, and improving numerical models. These recommendations are described in more detail at the end of this report.

Zhao, Y.; Ohadi, M.M.; Radermacher, R.

2001-09-15T23:59:59.000Z

304

Rate Schedules  

Energy.gov (U.S. Department of Energy (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...

305

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. 11 figs.

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

1984-12-25T23:59:59.000Z

306

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

307

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

1984-01-01T23:59:59.000Z

308

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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...

309

Experimental study on turbulent natural convection heat transfer in ...  

Science Conference Proceedings (OSTI)

Feb 16, 2010 ... ments are conducted to investigate flow and heat transfer ... turbulent region, the heat transfer deterioration occurs for a bubble flow rate Q = 33 ...

310

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

311

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...

312

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ... 222 194 17...

313

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings ... 2,100...

314

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ... 1,928 1,316...

315

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

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

316

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

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

317

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

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

318

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

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

319

Heat Pipes: An Industrial Application  

E-Print Network (OSTI)

This paper reviews the basics of heat pipe exchangers. Included are how they are constructed, how they operate, where they have application, and various aspects of evaluating a potential application. After discussing the technical aspects of heat pipe exchangers, an industrial case history is presented. The case history involves a retrofit project which added heat pipes to five natural draft process heaters with a combined heat duty of 150 M Btu/hr. A heat recovery of 15 M Btu/hr has resulted from the flue gas/combustion air interchange. The paper will include design considerations, and operating and maintenance history since early 1980. A second application for heat pipes with a 12 M Btu/hr duty installed in 1983 will also be discussed.

Murray, F.

1984-01-01T23:59:59.000Z

320

Operational Demonstration Program | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Operational Demonstration Program Operational Demonstration Program Operational Demonstration Program < Back Eligibility Commercial Savings Category Heating & Cooling Commercial Heating & Cooling Heating Home Weatherization Commercial Weatherization Sealing Your Home Cooling Construction Design & Remodeling Windows, Doors, & Skylights Ventilation Heat Pumps Appliances & Electronics Commercial Lighting Lighting Manufacturing Buying & Making Electricity Bioenergy Alternative Fuel Vehicles Hydrogen & Fuel Cells Water Energy Sources Solar Water Heating Wind Maximum Rebate $500,000 Program Info Funding Source CEFIA Start Date 2005 State Connecticut Program Type Industry Recruitment/Support Rebate Amount $150,000 - $500,000 Provider Clean Energy Finance and Investment Authority This program is currently closed. Applications were due in February 2012.

Note: This page contains sample records for the topic "operating heat rate" 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

German central solar heating plants with seasonal heat storage  

Science Conference Proceedings (OSTI)

Central solar heating plants contribute to the reduction of CO{sub 2}-emissions and global warming. The combination of central solar heating plants with seasonal heat storage enables high solar fractions of 50% and more. Several pilot central solar heating plants with seasonal heat storage (CSHPSS) built in Germany since 1996 have proven the appropriate operation of these systems and confirmed the high solar fractions. Four different types of seasonal thermal energy stores have been developed, tested and monitored under realistic operation conditions: Hot-water thermal energy store (e.g. in Friedrichshafen), gravel-water thermal energy store (e.g. in Steinfurt-Borghorst), borehole thermal energy store (in Neckarsulm) and aquifer thermal energy store (in Rostock). In this paper, measured heat balances of several German CSHPSS are presented. The different types of thermal energy stores and the affiliated central solar heating plants and district heating systems are described. Their operational characteristics are compared using measured data gained from an extensive monitoring program. Thus long-term operational experiences such as the influence of net return temperatures are shown. (author)

Bauer, D.; Marx, R.; Nussbicker-Lux, J.; Ochs, F.; Heidemann, W. [Institute of Thermodynamics and Thermal Engineering (ITW), University of Stuttgart, Pfaffenwaldring 6, D-70550 Stuttgart (Germany); Mueller-Steinhagen, H. [Institute of Thermodynamics and Thermal Engineering (ITW), University of Stuttgart, Pfaffenwaldring 6, D-70550 Stuttgart (Germany); Institute of Technical Thermodynamics (ITT), German Aerospace Centre (DLR), Stuttgart (Germany)

2010-04-15T23:59:59.000Z

322

Frostless heat pump having thermal expansion valves  

DOE Patents (OSTI)

A heat pump system having an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant and further having a compressor, an interior heat exchanger, an exterior heat exchanger, a heat pump reversing valve, an accumulator, a thermal expansion valve having a remote sensing bulb disposed in heat transferable contact with the refrigerant piping section between said accumulator and said reversing valve, an outdoor temperature sensor, and a first means for heating said remote sensing bulb in response to said outdoor temperature sensor thereby opening said thermal expansion valve to raise suction pressure in order to mitigate defrosting of said exterior heat exchanger wherein said heat pump continues to operate in a heating mode.

Chen, Fang C [Knoxville, TN; Mei, Viung C [Oak Ridge, TN

2002-10-22T23:59:59.000Z

323

Passive Core Decay Heat Removal Performance Guideline  

Science Conference Proceedings (OSTI)

Passive decay heat removal systems operate without pumps when normal heat removal systems are not available. Safety is ensured by confirming that an adequate thermal margin is provided to accommodate various operating conditions, design uncertainties, and degradation. Guidelines to ensure adequate thermal performance are provided for three different system configurations.This report introduces utility systems engineers to the design and operation of passive decay heat removal systems and ...

2013-11-26T23:59:59.000Z

324

CH Packaging Operations Manual  

Science Conference Proceedings (OSTI)

This procedure provides instructions for assembling the CH Packaging Drum payload assembly, Standard Waste Box (SWB) assembly, Abnormal Operations and ICV and OCV Preshipment Leakage Rate Tests on the packaging seals, using a nondestructive Helium (He) Leak Test.

Washington TRU Solutions LLC

2005-06-13T23:59:59.000Z

325

Discussions on Disposal Forms of Auxiliary Heat Source in Surface Water Heat Pump System  

E-Print Network (OSTI)

This paper presents two common forms of auxiliary heat source in surface water heat pump system and puts forward the idea that the disposal forms affect operation cost. It deduces operation cost per hour of the two forms. With a project calculation, it illuminates that the post-located auxiliary heat source cheaper and superior to the fore-located one.

Qian, J.; Sun, D.; Li, X.; Li, G.

2006-01-01T23:59:59.000Z

326

Quantum Operation Time Reversal  

E-Print Network (OSTI)

The dynamics of an open quantum system can be described by a quantum operation, a linear, complete positive map of operators. Here, I exhibit a compact expression for the time reversal of a quantum operation, which is closely analogous to the time reversal of a classical Markov transition matrix. Since open quantum dynamics are stochastic, and not, in general, deterministic, the time reversal is not, in general, an inversion of the dynamics. Rather, the system relaxes towards equilibrium in both the forward and reverse time directions. The probability of a quantum trajectory and the conjugate, time reversed trajectory are related by the heat exchanged with the environment.

Crooks, Gavin E

2007-01-01T23:59:59.000Z

327

Quantum Operation Time Reversal  

E-Print Network (OSTI)

The dynamics of an open quantum system can be described by a quantum operation, a linear, complete positive map of operators. Here, I exhibit a compact expression for the time reversal of a quantum operation, which is closely analogous to the time reversal of a classical Markov transition matrix. Since open quantum dynamics are stochastic, and not, in general, deterministic, the time reversal is not, in general, an inversion of the dynamics. Rather, the system relaxes towards equilibrium in both the forward and reverse time directions. The probability of a quantum trajectory and the conjugate, time reversed trajectory are related by the heat exchanged with the environment.

Gavin E. Crooks

2007-06-26T23:59:59.000Z

328

Operating Instructions  

Science Conference Proceedings (OSTI)

... ensure the maximum possible flow cross-section in ... thermostat ? external circuit ? flow-through cooler ... Heat transfer tubing and other hot parts ...

2012-02-14T23:59:59.000Z

329

Rates - WAPA-137 Rate Order  

NLE Websites -- All DOE Office Websites (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

330

Active Solar Heating Basics | Department of Energy  

NLE Websites -- All DOE Office Websites (Extended Search)

NREL Active Solar Heating Linear Concentrator System Basics for Concentrating Solar Power Rooftop solar water heaters need regular maintenance to operate at peak efficiency. |...

331

Multifamily Heat Pump Water Heater Evaluation  

SciTech Connect

Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16 month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

Hoeschele, M.; Weitzel, E.

2013-11-01T23:59:59.000Z

332

A comparison of ground source heat pumps and micro-combined heat and power as residential greenhouse gas reduction strategies  

E-Print Network (OSTI)

Both ground source heat pumps operating on electricity and micro-combined heat and power systems operating on fossil fuels offer potential for the reduction of green house gas emissions in comparison to the conventional ...

Guyer, Brittany (Brittany Leigh)

2009-01-01T23:59:59.000Z

333

Predicting Combined Operational and Residual Stress Fields and ...  

Science Conference Proceedings (OSTI)

Effects of Heat Treatments on Precipitates, Microstructures and Mechanical ... Electric Arc Furnace Operation with Electromagnetic Stirring and Hot Heel.

334

Micro loop heat pipe evaporator coherent pore structures  

E-Print Network (OSTI)

Loop heat pipes seem a promising approach for application in modern technologies where such thermal devices as cooling fans and radiators cannot satisfy overall requirements. Even though a loop heat pipe has a big potential to remove the thermal energy from a high heat flux source, the heat removal performance of heat pipes cannot be predicted well since a first principles of evaporation has not been established. An evaporation model based on statistical rate theory has been recently suggested by Ward and developed for a single pore by Oinuma. A loop heat pipe with coherent pore wick structure has been proposed as a design model. To limit product development risk and to enhance performance assurance, design model features and performance parameters have been carefully reviewed during the concept development phase and have been deliberately selected so as to be well-founded on the limited existing loop heat pipe knowledge base. A first principles evaporation model has been applied for evaporator geometry optimization. A number of iteration calculations have been performed to satisfy design and operating limitations. A set of recommendations for design optimization has been formulated. An optimal model has been found and proposed for manufacture and experimental investigation.

Alexseev, Alexandre Viktorovich

2003-08-01T23:59:59.000Z

335

Water heater heat reclaimer  

SciTech Connect

This invention relates to the conservation of energy in a domestic gas water heater by utilizing the hot exhaust gases in a gas water heater for the preheating of the incoming unheated water into the water heater. The exhaust gases from a domestic gas water heater carry wasted heat and the present invention provides a mean to reclaim part of the wasted heat for the preheating of the incoming unheated water during hot water usage periods. During non hot water usage periods the heat in the exhaust gases is not reclaimed to prevent overheating of the water and also to prevent the formation of water deposit in the preheating assembly or heat reclaimer. During the non hot water usage periods the heat produced in the water heater is normally needed only to maintain the desired water temperature of the stored water in the water tank of the water heater. Due to the rapid heating or recovery rate, the present invention enables the use of a smaller water heater. The use of a smaller water heater reduces the normal heat loss from the stored hot water thereby further reduces energy consumption.

Wie, C.T.

1983-08-09T23:59:59.000Z

336

Handbook of heat and mass transfer. Volumes 1 and 2  

Science Conference Proceedings (OSTI)

This two-volume series presents advanced topics in industrial heat and mass transfer operations for reactor design technology.

Cheremisinoff, N.P.

1985-01-01T23:59:59.000Z

337

The Cost of Heat Exchanger Fouling in the U. S. Industries  

E-Print Network (OSTI)

Fouling of heat exchangers costs the U.S. industries hundreds of millions of dollars every year in increased equipment costs, maintenance costs, energy losses and losses in production. The designer of heat exchangers usually allows for fouling by using a fouling factor in the design which results in additional capital cost of the heat exchanger. As fouling deposits build up in a heat exchanger, its performance will start to deteriorate and less energy will be transferred through the unit. A plot is provided that gives the percent decrease in heat flux, for a constant driving temperature difference, as a function of the clean overall heat transfer coefficient and the fouling factor. Another plot gives the increase in surface area due to fouling for the same heat transfer rate and driving temperature difference, as a function of the clean overall heat transfer coefficient and the fouling factor. The overall heat transfer market was divided into four sectors: the chemical, petroleum, electric utility and other industries. The 1982 U.S. sales of all industrial heat exchangers, excepting boilers and automotive radiators, was about 285,000 units amounting to about $1.6 billion. The total heat duty of all the heat exchangers in industrial operation, including electric utilities, was estimated at 11.7 Quads. If this represented the amount of heat transferred through clean heat exchangers, the decrease in energy transferred due to fouling or the cost of fouling in terms of energy lost was estimated at 2.9 Quads annually. The cost of fouling, in providing for additional surface area to compensate for a decrease in heat transfer, was conservatively estimated at $180 million in 1982.

Rebello, W. J.; Richlen, S. L.; Childs, F.

1988-09-01T23:59:59.000Z

338

Energy Rating  

E-Print Network (OSTI)

Consistent, accurate, and uniform ratings based on a single statewide rating scale Reasonable estimates of potential utility bill savings and reliable recommendations on cost-effective measures to improve energy efficiency Training and certification procedures for home raters and quality assurance procedures to promote accurate ratings and to protect consumers Labeling procedures that will meet the needs of home buyers, homeowners, renters, the real estate industry, and mortgage lenders with an interest in home energy ratings

Cabec Conference; Rashid Mir P. E

2009-01-01T23:59:59.000Z

339

Insertion Rates  

Science Conference Proceedings (OSTI)

HOME > Insertion Rates. TECH HEADLINES. Research Explores a New Layer in Additive Manufacturin... Grand Opening Slated for Electron Microscopy Facility.

340

Gas Turbine/Solar Parabolic Trough Hybrid Design Using Molten Salt Heat Transfer Fluid: Preprint  

DOE Green Energy (OSTI)

Parabolic trough power plants can provide reliable power by incorporating either thermal energy storage (TES) or backup heat from fossil fuels. This paper describes a gas turbine / parabolic trough hybrid design that combines a solar contribution greater than 50% with gas heat rates that rival those of natural gas combined-cycle plants. Previous work illustrated benefits of integrating gas turbines with conventional oil heat-transfer-fluid (HTF) troughs running at 390?C. This work extends that analysis to examine the integration of gas turbines with salt-HTF troughs running at 450 degrees C and including TES. Using gas turbine waste heat to supplement the TES system provides greater operating flexibility while enhancing the efficiency of gas utilization. The analysis indicates that the hybrid plant design produces solar-derived electricity and gas-derived electricity at lower cost than either system operating alone.

Turchi, C. S.; Ma, Z.

2011-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "operating heat rate" 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

DESIGN OF A COMPACT HEAT EXCHANGER FOR HEAT RECUPERATION FROM A HIGH TEMPERATURE ELECTROLYSIS SYSTEM  

Science Conference Proceedings (OSTI)

Design details of a compact heat exchanger and supporting hardware for heat recuperation in a high-temperature electrolysis application are presented. The recuperative heat exchanger uses a vacuum-brazed plate-fin design and operates between 300 and 800°C. It includes corrugated inserts for enhancement of heat transfer coefficients and extended heat transfer surface area. Two recuperative heat exchangers are required per each four-stack electrolysis module. The heat exchangers are mated to a base manifold unit that distributes the inlet and outlet flows to and from the four electrolysis stacks. Results of heat exchanger design calculations and assembly details are also presented.

G. K. Housley; J.E. O'Brien; G.L. Hawkes

2008-11-01T23:59:59.000Z

342

Increasing Confidence In Geothermal Heat Pump Design Methods  

SciTech Connect

Sizing the ground heat exchanger is one of the most important tasks in the design of a geothermal heat pump (GHP) system. Undersizing the heat exchanger can result in poor operating efficiency, reduced comfort, and nuisance heat pump lockouts on safety controls, while an oversized heat exchanger increases the installation cost of the system. The cost of ground loop installation may mean the difference between a feasible and an unfeasible project. Thus there are strong incentives to select heat exchanger lengths which allow satisfactory performance under all operating conditions within a feasible project budget. Sizing a ground heat exchanger is not a simple calculation. In the first place, there is usually some uncertainty in the peak block and annual space conditioning loads for the building to be served by the GHPs. The thermal properties of the soil formation may be unknown as well. Drilling logs and core samples can identify the soil type, but handbook values for the thermal properties of soils vary widely. Properly-done short-term on-site tests and data analysis to obtain thermal properties provide more accurate information, but since these tests are expensive they are usually only feasible in large projects. Given the uncertainties inherent in the process, if designers were truly working 'close to the edge' - selecting the absolute minimum heat exchanger length required to meet the predicted loads - one would expect to see more examples of undersized heat exchangers. Indeed there have been a few. However, over the past twenty years GHPs have been installed and successfully operated at thousands of locations all over the world. Conversations with customers and facility managers reveal a high degree of satisfaction with the technology, but studies of projects reveal far more cases of generously sized ground heat exchangers than undersized ones. This indicates that the uncertainties in space conditioning loads and soil properties are covered by a factor of safety. These conservative designs increase the installed cost of GHP systems, limiting their use and applicability. Moreover, as ground heat exchanger sizing methods have improved, they have suggested (and field tests are beginning to verify) that standard bore backfill practices lead to unnecessarily large ground heat exchangers. Growing evidence suggests that in many applications use of sand backfill with a grout plug at the surface, or use of bottom-to-top thermally enhanced grout, may provide groundwater protection equal to current practice at far less cost. Site tests of thermal properties provides more accurate information, but since these tests are expensive they are usually only performed in large projects. Even so, because soil properties can vary over a distance as small as a few feet, the value of these tests is limited. One objective of ongoing research at the Oak Ridge National Laboratory (ORNL) is to increase designers confidence in available ground heat exchanger sizing methods that lead to reliable yet cost-effective designs. To this end we have developed research-grade models that address the interactions between buildings, geothermal heat pump systems and ground heat exchangers The first application of these models was at Fort Polk, Louisiana, where the space conditioning systems of over 4,000 homes were replaced with geothermal heat pumps (Shonder and Hughes, 1997; Hughes et. al., 1997). At Fort Polk, the models were calibrated to detailed data from one of the residences. Data on the energy use of the heat pump, combined with inlet and outlet water temperature and flow rate in the ground heat exchangers, allowed us to determine the thermal properties of the soil formation being experienced by the operating GHP system. Outputs from the models provide all the data required by the various commercially-available ground loop sizing programs. Accurate knowledge of both the building loads and the soil properties eliminated the uncertainty normally associated with the design process, and allowed us to compare the predictions of the commercially-available

Shonder, John A [ORNL; Hughes, Patrick [ORNL

1998-03-01T23:59:59.000Z

343

The deterioration in heat transfer to fluids at supercritical pressure and high heat fluxes  

E-Print Network (OSTI)

At slightly supercritical pressure and in the neighborhood of the pseudo-critical temperature (defined as the temperature corresponding to the peak in specific heat at the operating pressure), the heat transfer coefficient ...

Shiralkar, B. S.

1968-01-01T23:59:59.000Z

344

Heat Stroke  

NLE Websites -- All DOE Office Websites (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– 

345

Heat reclaimer  

Science Conference Proceedings (OSTI)

A device for reclaiming heat from stove pipes and the like. A semi-circular shaped hollow enclosed housing with a highly thermal-conductive concave surface is mounted contactingly to surround approximately one-half of the circumference of the stove pipe. The concave surface is formed to contact the pipe at a maximum number of points along that surface. The hollow interior of the housing contains thin multi-surfaced projections which are integral with the concave surface and conductively transfer heat from the stove pipe and concave surface to heat the air in the housing. A fan blower is attached via an air conduit to an entrance opening in the housing. When turned on, the blower pushes the heated interior air out a plurality of air exit openings in the ends of the housing and brings in lower temperature outside air for heating.

Parham, F.

1985-04-09T23:59:59.000Z

346

Heat transfer. [heat transfer roller employing a heat pipe  

SciTech Connect

A heat transfer roller embodying a heat pipe is disclosed. The heat pipe is mounted on a shaft, and the shaft is adapted for rotation on its axis.

Sarcia, D.S.

1978-05-23T23:59:59.000Z

347

Solar industrial process heat  

DOE Green Energy (OSTI)

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

Lumsdaine, E.

1981-04-01T23:59:59.000Z

348

Improvement of xenon purification system using a combination of a pulse tube refrigerator and a coaxial heat exchanger  

E-Print Network (OSTI)

We have developed a compact cryogenic system with a pulse tube refrigerator and a coaxial heat exchanger. This liquefaction-purification system not only saves the cooling power used to reach high gaseous recirculation rate, but also reduces the impurity level with high speed. The heat exchanger operates with an efficiency of 99%, which indicates the possibility for fast xenon gas recirculation in a highpressurized large-scale xenon storage with much less thermal losses.

Chen, Wan-Ting; Cussonneau, J -P; Donnard, J; Duval, S; Lemaire, O; Calloch, M Le; Ray, P Le; Mohamad-Hadi, A -F; Morteau, E; Oger, T; Scotto-Lavina, L; Stutzmann, J -S; Thers, D; Briend, P; Haruyama, T; Mihara, S; Tauchi, T

2012-01-01T23:59:59.000Z

349

HEAT TRANSFER ANALYSIS AND DESIGN OF A PLUGGING INDICATOR SYSTEM FOR SRE  

SciTech Connect

The analysis was performed on a system comprising a counterflow, concentric-pipe economizer, heat exchanger, flowmeter, plug, and connecting pipe. The system was assumed to be at some initial temperature equal to the inlet sodium temperature and suddenly loses heat to a medium in the heat exchanger. Design and operating data are presented. A cooling rate curve is given where the nitrogen flow rate is decreased when the plug temperature reaches 400 deg F. The time variation of minimum temperatures is given for various values of thermal capacitance with constant equilibrium temperature, and the economizer parameter with constant equilibrium temperatures and thermal capacitance. The variation in heat exchanger parameter with economizer parameter for a constant equilibrium minimum temperature of 250 deg F, and a constant inlet temperature of 750 deg F is indicated. (B.O.G.)

Sletten, H.L.

1955-04-01T23:59:59.000Z

350

AVESTAR® - Training - Combined Cycle Operations  

NLE Websites -- All DOE Office Websites (Extended Search)

Exercise Startup Circulating Water System Startup Fuel Systems Draw vacuum in Condenser Start Gas Turbine (GT) and bring to rated speed on natural gas ITS operations to...

351

PARALLEL OPERATION OF WELDING GENERATORS  

SciTech Connect

Eight 900-amp, 36-kw direct current welding generators driven by eight 60-hp induction motors were operated in parallel to supply up to 7200 amp to resistance loads for heat transfer studies. A description and circuit designs of this installation, which provides safety interlocks and permits sectionalized operation for separate leads, are given. (auth)

Butler, B.H.

1960-06-01T23:59:59.000Z

352

Rate schedule  

NLE Websites -- All DOE Office Websites (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

353

CRBRP decay heat removal systems  

SciTech Connect

The Decay Heat Removal Systems for the Clinch River Breeder Reactor Plant (CRBRP) are designed to adequately remove sensible and decay heat from the reactor following normal shutdown, operational occurrences, and postulated accidents on both a short term and a long term basis. The Decay Heat Removal Systems are composed of the Main Heat Transport System, the Main Condenser and Feedwater System, the Steam Generator Auxiliary Heat Removal System (SGAHRS), and the Direct Heat Removal Service (DHRS). The overall design of the CRBRP Decay Heat Removal Systems and the operation under normal and off-normal conditions is examined. The redundancies of the system design, such as the four decay heat removal paths, the emergency diesel power supplies, and the auxiliary feedwater pumps, and the diversities of the design such as forced circulation/natural circulation and AC Power/DC Power are presented. In addition to overall design and system capabilities, the detailed designs for the Protected Air Cooled Condensers (PACC) and the Air Blast Heat Exchangers (ABHX) are presented.

Hottel, R.E.; Louison, R.; Boardman, C.E.; Kiley, M.J.

1977-01-01T23:59:59.000Z

354

User manual for GEOCITY: a computer model for geothermal district heating cost analysis  

DOE Green Energy (OSTI)

A computer model called GEOCITY has been developed to systematically calculate the potential cost of district heating using hydrothermal geothermal resources. GEOCITY combines climate, demographic factors, and heat demand of the city, resource conditions, well drilling costs, design of the distribution system, tax rates, and financial factors into one systematic model. The GEOCITY program provides the flexibility to individually or collectively evaluate the impact of different economic and technical parameters, assumptions, and uncertainties on the cost of providing district heat from a geothermal resource. Both the geothermal reservoir and distribution system are simulated to model the complete district heating system. GEOCITY consists of two major parts: the geothermal reservoir submodel and the distribution submodel. The reservoir submodel calculates the unit cost of energy by simulating the exploration, development, and operation of a geothermal reservoir and the transmission of this energy to a distribution center. The distribution submodel calculates the unit cost of heat by simulating the design and operation of a district heating distribution system. GEOCITY calculates the unit cost of energy and the unit cost of heat for the district heating system based on the principle that the present worth of the revenues will be equal to the present worth of the expenses including investment return over the economic life of the distribution system.

Huber, H.D.; McDonald, C.L.; Bloomster, C.H.; Schulte, S.C.

1978-10-01T23:59:59.000Z

355

Heat transport system, method and material  

DOE Patents (OSTI)

A heat transport system, method and composite material in which a plurality of hollow spherical shells or microspheres having an outside diameter of less than or equal to 500 microns are encapsulated or embedded within a bulk material. Each shell has captured therein a volatile working fluid, such that each shell operates as a microsized heat pipe for conducting heat through the composite structure.

Musinski, Donald L. (Saline, MI)

1987-01-01T23:59:59.000Z

356

Development of a cryogenic heat pipe  

SciTech Connect

Heat pipe operating characteristics can be used to advantage in cryogenic systems. Diode operation of the heat pipe, the ability to conduct heat in one direction only, is useful in protecting the heat load if the heat sink temperature rises above the load temperature. Because of this, the heat pipe can be made to act as a thermal switch. A screened-wick, inverted-artery, cryogenic heat pipe was designed, fabricated, and tested. The tests were first conducted with hydrogen and then with oxygen as the working fluid. Heat pipe performance limits were measured as a function of operating temperature, and startup from both the supercritical and the frozen state was demonstrated. The heat pipe was designed to operate as a thermal diode, and transient tests were used to determine the turndown ratio. The heat pipe test results were correlated with the Los Alamos heat pipe computer code and good agreement was obtained between the predicted and measured performance. The heat pipe was developed for spacecraft sensor cooling applications. Test results show significant performance advantages over solid conductors.

Prenger, F.C.; Stewart, W.F.; Runyan, J.E.

1993-08-01T23:59:59.000Z

357

Testing of a sodium heat pipe  

SciTech Connect

The operation of a heat pipe with both thermal radiation and convection heat rejection has been experimentally examined. The thermal radiation heat rejection conditions are similar to those which would be experienced in a space environment. The experimental results show good agreement with the analytical model. 3 refs., 2 figs.

Holtz, R.E.

1991-01-01T23:59:59.000Z

358

Integrated Approach to Revamping Heat Exchangers Networks  

E-Print Network (OSTI)

A heat exchanger network constitutes the core of the plant energy systems interlinking the core process operation and the utility systems. This paper will illustrate an integrated approach for the revamp of a heat exchanger network by bringing together process simulation, pinch analysis and detailed heat exchanger design tools. The paper will illustrate the methodology using a refinery example.

Glass, K. E.; Dhole, V.; Wang, Y.

2002-04-01T23:59:59.000Z

359

Energy Basics: Heat Pump Systems  

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

Systems Air-Source Heat Pumps Ductless Mini-Split Heat Pumps Absorption Heat Pumps Geothermal Heat Pumps Supporting Equipment for Heating & Cooling Systems Water Heating Heat...

360

ADVANCED HEAT EXCHANGERS USING TUNABLE NANOSCALE-MOLECULAR ASSEMBLY  

Science Conference Proceedings (OSTI)

Steam condensation heat transfer on smooth horizontal tubes and enhanced tubes (TURBO-CDI and TURBO-CSL) along with nanoscale hydrophobic coated tubes was studied experimentally. Hydrophobic coatings have been created through self-assembled mono layers (SAMs) on copper alloy (99.9% Cu, 0.1% P) surfaces to enhance steam condensation through dropwise condensation. In general, a SAM system with a long-chain, hydrophobic group is nano-resistant, meaning that such a system forms a protective hydrophobic layer with negligible heat transfer resistance but a much stronger bond. When compared to complete filmwise condensation, the SAM coating on a plain tube increased the condensation heat transfer rate by a factor of 3 for copper alloy surfaces, under vacuum pressure (33.86 kPa) and by a factor of about 8 times when operated at atmospheric pressure (101 kPa). Lifetime of maintaining dropwise condensation is greatly dependent on the processing conditions.

Kwang J. Kim; Thomas W. Bell; Srinivas Vemuri; Sailaja Govindaraju

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "operating heat rate" 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

Industrial Heat Recovery - 1982  

E-Print Network (OSTI)

Two years ago I summarized 20 years of experience on Industrial Heat Recovery for the Energy-source Technology Conference and Exhibition held in New Orleans, Louisiana. At the end of that paper I concluded with brief advice on 'How to specify heat recovery equipment.' The two years which have elapsed since then have convinced me that proper specification assures the most reliable equipment at the lowest price. The most economical specification describes the operating and site data but leaves the design details for the supplier. A true specialist will be able to provide you with the latest technology at the best possible price. This paper explores the impact of specifications on heat recovery equipment and its associated cost.

Csathy, D.

1982-01-01T23:59:59.000Z

362

Modular heat exchanger  

DOE Patents (OSTI)

A heat exchanger for use in nuclear reactors includes a heat exchange tube bundle formed from similar modules each having a hexagonal shroud containing a large number of thermally conductive tubes which are connected with inlet and outlet headers at opposite ends of each module, the respective headers being adapted for interconnection with suitable inlet and outlet manifold means. In order to adapt the heat exchanger for operation in a high temperature and high pressure environment and to provide access to all tube ports at opposite ends of the tube bundle, a spherical tube sheet is arranged in sealed relation across the chamber with an elongated duct extending outwardly therefrom to provide manifold means for interconnection with the opposite end of the tube bundle.

Culver, Donald W. (Poway, CA)

1978-01-01T23:59:59.000Z

363

Heat reclaimer  

SciTech Connect

An apparatus for reclaiming heat from the discharge gas from a combustion fuel heating unit, which has: inlet and outlet sections; an expansion section whose circumference gradually increases in the direction of flow, thereby providing an increased area for heat transfer; flow splitter plates which lie within and act in conjunction with the expansion section wall to form flow compartments, which flow splitter plates and expansion section wall have a slope, with respect to the centroidal axis of the flow compartment not exceeding 0.1228, which geometry prevents a separation of the flow from the enclosing walls, thereby increasing heat transfer and maintaining the drafting function; and a reduction section which converges the flow to the outlet section.

Horkey, E.J.

1982-06-29T23:59:59.000Z

364

Cooperative heat transfer and ground coupled storage system  

DOE Patents (OSTI)

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

Metz, Philip D. (Rocky Point, NY)

1982-01-01T23:59:59.000Z

365

Process Heating  

Science Conference Proceedings (OSTI)

This technical update uses real world examples to discuss applications of electrotechnology in industrial process heating and to highlight some of the emerging technologies in this field. These emerging technologies, when implemented in a plant, will provide significant energy savings as well as increase productivity. The report presents three case studies of successful implementation of two different electric process-heating technologies in three different industries. The case studies show that in some ...

2011-12-07T23:59:59.000Z

366

HEAT EXCHANGER  

DOE Patents (OSTI)

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

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

1962-10-23T23:59:59.000Z

367

Corrosive resistant heat exchanger  

DOE Patents (OSTI)

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

Richlen, Scott L. (Annandale, VA)

1989-01-01T23:59:59.000Z

368

Installation package for a solar heating system  

DOE Green Energy (OSTI)

Installation information is presented for a solar heating system installed in Concho Indian School at El Reno, Oklahoma. This package includes a system Operation and Maintenance Manual, hardware brochures, schematics, system operating modes and drawings. The Solar Engineering and Equipment Company (SEECO) developed this prototype solar heating system consisting of the following subsystems: solar collectors, control and storage.

Not Available

1978-12-01T23:59:59.000Z

369

Guidance for an Effective Heat Exchanger Program  

Science Conference Proceedings (OSTI)

Heat exchangers are used extensively in the nuclear power generation industry. Their proper operation is essential for reliable and safe nuclear plant operation. Increased emphasis on heat exchanger reliability at nuclear power plants has resulted in the development of engineering programs or equivalent actions to maintain the required thermal performance and structural integrity.

2011-10-04T23:59:59.000Z

370

Philip, South Dakota geothermal district heating systems  

SciTech Connect

The geothermal heating project in Philip, South Dakota which uses the waste water from the Haakon School has now been in operation for 15 years. This project was one of the 23 cost shared by the U.S. DOE starting in 1978, of which 15 became operational. This article describes the geothermal heating system for eight buildings in downtown Philip.

Lund, J.W.

1997-12-01T23:59:59.000Z

371

User’s Guide for Getter Rate Test System  

DOE Green Energy (OSTI)

This User’s Guide describes the operation and maintenance of the Getter Rate Test System, including the mechanical equipment, instrumentation, and datalogger/computer components. The Getter Rate Test System includes equipment and instrumentation to conduct two getter rate tests simultaneously. The mechanical equipment comprises roughing and high-vacuum pumps, heated test chambers, standard hydrogen leaks, and associated piping and valves. Instrumentation includes thermocouples, pressure (vacuum) transducers, panel displays, analog-to-digital signal converter, and associated wiring. The datalogger/computer is a stand-alone computer with installed software to allow the user to record data input from the pressure transducers to data files and to calculate the getter rate from the data in an Excel® spreadsheet.

Elmore, Monte R.

2007-06-27T23:59:59.000Z

372

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

373

Heat Recovery in Building Envelopes  

SciTech Connect

Infiltration has traditionally been assumed to contribute to the energy load of a building by an amount equal to the product of the infiltration flow rate and the enthalpy difference between inside and outside. Application of such a simple formula may produce an unreasonably high contribution because of heat recovery within the building envelope. Previous laboratory and simulation research has indicated that such heat transfer between the infiltrating air and walls may be substantial. In this study, Computational Fluid Dynamics was used to simulate sensible heat transfer in typical envelope constructions. The results show that the traditional method may over-predict the infiltration energy load by up to 95 percent at low leakage rates. A simplified physical model has been developed and used to predict the infiltration heat recovery based on the Peclet number of the flow and the fraction of the building envelope active in infiltration heat recovery.

Sherman, Max H.; Walker, Iain S.

2001-01-01T23:59:59.000Z

374

OPERATIONS (OPS)  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

OPS) OPS) OBJECTIVE OPS.1 The formality and discipline of operations is adequate to conduct work safely and programs are in place to maintain this formality and discipline. (CR 13) Scope: The Conduct of Operations Program was evaluated during the recent KE Basin FTS ORR and was found to be adequately implemented. Based on this result and the subsequent program enhancements, the scope of the review is to be limited to the SWS operating and maintenance evolutions. Criteria * Programmatic elements of conduct of operations are in place for SWS operations. (DOE Order 5480.19) * The SWS operations personnel adequately demonstrate the principles of conduct of operations requirements during the shift performance period. (DOE Order 5480.19)

375

Heat transport system  

DOE Patents (OSTI)

A heat transport system of small size which can be operated in any orientation consists of a coolant loop containing a vaporizable liquid as working fluid and includes in series a vaporizer, a condenser and two one-way valves and a pressurizer connected to the loop between the two valves. The pressurizer may be divided into two chambers by a flexible diaphragm, an inert gas in one chamber acting as a pneumatic spring for the system.

Pierce, Bill L. (Pittsburgh, PA)

1978-01-01T23:59:59.000Z

376

Geothermal district heating system feasibility analysis, Thermopolis, Wyoming  

DOE Green Energy (OSTI)

The purpose of this study is to determine the technical and economic feasibility of constructing and operating a district heating system to serve the residential, commercial, and public sectors in Thermopolis. The project geothermal resource assessment, based on reviews of existing information and data, indicated that substantial hot water resources likely exist in the Rose Dome region 10 miles northeast of Thermopolis, and with quantities capable of supporting the proposed geothermal uses. Preliminary engineering designs were developed to serve the space heating and hot water heating demands for buildings in the Thermopolis-East Thermopolis town service area. The heating district design is based on indirect geothermal heat supply and includes production wells, transmission lines, heat exchanger units, and the closed loop distribution and collection system necessary to serve the individual customers. Three options are presented for disposal of the cooled waters-reinjection, river disposal, and agricultural reuse. The preliminary engineering effort indicates the proposed system is technically feasible. The design is sized to serve 1545 residences, 190 businesses, and 24 public buildings. The peak design meets a demand of 128.2 million Btu at production rates of 6400 gpm.

Goering, S.W.; Garing, K.L.; Coury, G.; Mickley, M.C.

1982-04-26T23:59:59.000Z

377

DWPF Macrobatch 2 Melt Rate Tests  

SciTech Connect

The Defense Waste Processing Facility (DWPF) canister production rate must be increased to meet canister production goals. Although a number of factors exist that could potentially increase melt rate, this study focused on two: (1) changes in frit composition and (2) changes to the feed preparation process to alter the redox of the melter feed. These two factors were investigated for Macrobatch 2 (sludge batch 1B) utilizing crucible studies and a specially designed ''melt rate'' furnace. Other potential factors that could increase melt rate include: mechanical mixing via stirring or the use of bubblers, changing the power skewing to redistribute the power input to the melter, and elimination of heat loss (e.g. air in leakage). The melt rate testing in FY00 demonstrated that melt rate can be improved by adding a different frit or producing a much more reducing glass by the addition of sugar as a reductant. The frit that melted the fastest in the melt rate testing was Frit 165. A paper stud y was performed using the Product Composition Control System (PCCS) to determine the impact on predicted glass viscosity, liquidus, durability, and operating window if the frit was changed from Frit 200 to Frit 165. PCCS indicated that the window was very similar for both frits. In addition, the predicted viscosity of the frit 165 glass was 46 poise versus 84 poise for the Frit 200 glass. As a result, a change from Frit 200 to Frit 165 is expected to increase the melt rate in DWPF without decreasing waste loading.

Stone, M.E.

2001-01-03T23:59:59.000Z

378

The heat transfer mechanism in aqueous foam flow in a channel  

Science Conference Proceedings (OSTI)

The Heat transfer mechanism in two-phase aqueous foam flow was investigated for developing energy-efficient heat exchangers. Such heat exchangers can provide low consumption of energy resources due to enhanced heat transfer rates. An enhanced heat transfer ... Keywords: aqueous foam flow, heat exchangers, heat transfer

Irena Gabrielaitien?; Jonas Gylys; Rolandas Jonynas; Tadas Ždankus

2011-12-01T23:59:59.000Z

379

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

380

Design, construction, operation, and evaluation of solar systems for industrial process-heat applications in the intermediate-temperature range (212/sup 0/F to 550/sup 0/F). Environmental assessment  

DOE Green Energy (OSTI)

The environmental impacts are assessed for a proposed 50,000 square foot field of single axis tracking, concentrating solar collectors along the Ohio River in southern Ohio. The facility is planned to produce process steam for use in the production of polystyrene. Absorbed solar energy would heat an aliphatic hydrocarbon synthetic heat transfer fluid to a maximum temperature of 500/sup 0/F. The existing environment is briefly described, particularly regarding air quality. The potential environmental impacts of the solar process heat system on the air, water, soil, endangered species and archaeological and historical resources are examined, including risks due to flood and glare and a comparison of alternatives. Also included are a Consent Judgment relating to two coal-fired boilers in violation of EPA regulations, property data of Gulf Synfluid 4CS (a candidate heat transfer fluid), piping and instrumentation diagrams and schematics, site grade and drainage plan, geological survey map, subsurface soil investigation, Ohio endangered species list, Ohio Archaeological Counsel certification list, and a study of heat transfer fluids and their properties. (LEW)

Not Available

Note: This page contains sample records for the topic "operating heat rate" 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

Control system for solar heating and cooling  

DOE Green Energy (OSTI)

A control system is being developed that will be capable of operating solar heating and cooling systems covering a wide range of configurations, and using different operating strategies that may be optimal for different climatic regions. To insure widespread applicability of the control system, it is being designed to allow for modification for operating with essentially all practical heating and cooling system configurations and control algorithms simply by interchange of replaceable modules in the circuitry. An experimental heating and cooling system, the main purpose of which is to allow testing and exercise of the controller, was designed so that it could be operated in these various configurations.

Wahlig, M.; Binnall, E.; Dols, C.; Graven, R.; Selph, F.; Shaw, R.; Simmons, M.

1975-08-01T23:59:59.000Z

382

Definition: System Operating Limit | Open Energy Information  

Open Energy Info (EERE)

Operating Limit Operating Limit Jump to: navigation, search Dictionary.png System Operating Limit The value (such as MW, MVar, Amperes, Frequency or Volts) that satisfies the most limiting of the prescribed operating criteria for a specified system configuration to ensure operation within acceptable reliability criteria. System Operating Limits are based upon certain operating criteria. These include, but are not limited to: Facility Ratings (Applicable pre- and post- Contingency equipment or facility ratings), Transient Stability Ratings (Applicable pre- and post-Contingency Stability Limits), Voltage Stability Ratings (Applicable pre- and post- Contingency Voltage Stability), System Voltage Limits (Applicable pre- and post- Contingency Voltage Limits)[1] Also Known As SOL

383

Heat pipe turbine vane cooling  

SciTech Connect

The applicability of using heat pipe principles to cool gas turbine vanes is addressed in this beginning program. This innovative concept involves fitting out the vane interior as a heat pipe and extending the vane into an adjacent heat sink, thus transferring the vane incident heat transfer through the heat pipe to heat sink. This design provides an extremely high heat transfer rate and a uniform temperature along the vane due to the internal change of phase of the heat pipe working fluid. Furthermore, this technology can also eliminate hot spots at the vane leading and trailing edges and increase the vane life by preventing thermal fatigue cracking. There is also the possibility of requiring no bleed air from the compressor, and therefore eliminating engine performance losses resulting from the diversion of compressor discharge air. Significant improvement in gas turbine performance can be achieved by using heat pipe technology in place of conventional air cooled vanes. A detailed numerical analysis of a heat pipe vane will be made and an experimental model will be designed in the first year of this new program.

Langston, L.; Faghri, A. [Connecticut Univ., Storrs, CT (United States). Dept. of Mechanical Engineering

1995-12-31T23:59:59.000Z

384

Initial Operation of the High Temperature Electrolysis Integrated Laboratory Scale Experiment at INL  

DOE Green Energy (OSTI)

An integrated laboratory scale, 15 kW high-temperature electrolysis facility has been developed at the Idaho National Laboratory under the U.S. Department of Energy Nuclear Hydrogen Initiative. Initial operation of this facility resulted in over 400 hours of operation with an average hydrogen production rate of approximately 0.9 Nm3/hr. The integrated laboratory scale facility is designed to address larger-scale issues such as thermal management (feed-stock heating, high-temperature gas handling), multiple-stack hot-zone design, multiple-stack electrical configurations, and other “integral” issues. This paper documents the initial operation of the ILS, with experimental details about heat-up, initial stack performance, as well as long-term operation and stack degradation.

C. M. Stoots; J. E. O'Brien; K. G. Condie; J. S. Herring; J. J. Hartvigsen

2008-06-01T23:59:59.000Z

385

Government Operation  

Science Conference Proceedings (OSTI)

Use Cases from NBD(NIST Big Data) Requirements WG V1.0. http://bigdatawg. nist.gov/home.php. Contents. Blank Template. Government Operation ...

2013-09-07T23:59:59.000Z

386

Operations Research  

E-Print Network (OSTI)

Mar 1, 2005 ... Operations Research. Report 2005-01. On a closedness theorem. Miklós Ujvári. Marc 2005. Eötvös Loránd University of Sciences. Department ...

387

Operating Instructions  

Science Conference Proceedings (OSTI)

... The system operation is center around 3 areas of the equipment 1) Deposition chamber 2) Vaporizer 3) Chiller/cold finger ...

2013-01-18T23:59:59.000Z

388

Waste Heat Recovery from Refrigeration in a Meat Processing Facility  

E-Print Network (OSTI)

A case study is reviewed on a heat recovery system installed in a meat processing facility to preheat water for the plant hot water supply. The system utilizes waste superheat from the facility's 1,350-ton ammonia refrigeration system. The heat recovery system consists of a shell and tube heat exchanger (16"? x 14'0") installed in the compressor hot gas discharge line. Water is recirculated from a 23,000-gallon tempered water storage tank to the heat exchanger by a circulating pump at the rate of 100 gallons per minute. All make-up water to the plant hot water system is supplied from this tempered water storage tank, which is maintained at a constant filled level. Tests to determine the actual rate of heat recovery were conducted from October 3, 1979 to October 12, 1979, disclosing an average usage of 147,000 gallons of hot water daily. These tests illustrated a varied heat recovery of from 0.5 to 1.0 million BTU per hour. The deviations were the result of both changing refrigeration demands and compressor operating modes. An average of 16 million BTU per day was realized, resulting in reduced boiler fuel costs of $30,000 annually, based on the present $.80 per gallon #2 fuel oil price. At the total installed cost of $79,000, including test instrumentation, the project was found to be economically viable. The study has demonstrated the technical and economic feasibility of refrigeration waste heat recovery as a positive energy conservation strategy which has broad applications in industry and commerce.

Murphy, W. T.; Woods, B. E.; Gerdes, J. E.

1980-01-01T23:59:59.000Z

389

Rates and Repayment Services  

NLE Websites -- All DOE Office Websites (Extended Search)

Tariff Rates FY 2014 Rates and Rate Schedules FY 2013 Rates and Rate Schedules FY 2012 Rates and Rate Schedules FY 2011 Rates and Rate Schedules FY 2010 Rates and Rate Schedules FY...

390

HEAT GENERATION  

DOE Patents (OSTI)

Heat is generated by the utilization of high energy neutrons produced as by nuclear reactions between hydrogen isotopes in a blanket zone containing lithium, a neutron moderator, and uranium and/or thorium effective to achieve multtplicatton of the high energy neutron. The rnultiplied and moderated neutrons produced react further with lithium-6 to produce tritium in the blanket. Thermal neutron fissionable materials are also produced and consumed in situ in the blanket zone. The heat produced by the aggregate of the various nuclear reactions is then withdrawn from the blanket zone to be used or otherwise disposed externally. (AEC)

Imhoff, D.H.; Harker, W.H.

1963-12-01T23:59:59.000Z

391

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

392

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

393

Heat pipe theory and practice: a sourcebook  

SciTech Connect

An introduction to heat pipe operating principles, types, and applications followed by a comprehensive treatment of heat pipe theory, design, and manufacture are presented. The organization of heat pipe theory provides parallel treatment of the fundamental laws of thermodynamics, heat transfer, fluid mechanics, and materials science during heat pipe analysis. For the problem-solving convenience of practicing engineers, design procedures are developed summarizing theoretical information. Methods of summarizing voluminous research information are presented in detail. Current practices in the manufacture of heat pipes are described. Current and potential applications of the heat pipe to energy systems discussed are: heat exchangers, heat recovery for HVAC systems, residential buildings, industrial processes, gasification plants, and thermal storage subsystems.

Chi, S.W.

1976-01-01T23:59:59.000Z

394

Geothermal Heat Pump Systems: Applications and Technology Development  

Science Conference Proceedings (OSTI)

This report discusses a hybrid geothermal heat pump system, an efficient, all-electric heating and cooling option for small and large commercial buildings. In this system, the ground loop heat exchanger is sized for winter heating and supplemented by auxiliary heat rejection devices (such as fluid coolers or cooling towers) for summer operation that prevent performance-impeding heat buildup in the earth surrounding the ground loop.

2003-11-03T23:59:59.000Z

395

Operations research  

Science Conference Proceedings (OSTI)

In Evita, Andrew Lloyd Webber and Tim Rice wrote: Politics, the Art of the Possible. To those of us in the operations research community, we postulate: Operations Research, the Science of Better - (i.e. better processes, better systems and better decisions). ...

William P. Pierskalla

2009-01-01T23:59:59.000Z

396

Operation crosscheck  

SciTech Connect

This report consists of three sections covering the three major areas of Lawrence Livermore Laboratory`s participation in Operation Crosscheck. These areas are: Diagnostic Aircraft; Radiochemical Sampling; and Device Assembly and Handling, Barbers Point. The information contained in these sections has been extracted from Crosscheck post-operation reports.

Gilbert, F. C.

1964-11-06T23:59:59.000Z

397

Transient analysis of a two-phase hydrogen heat switch  

DOE Green Energy (OSTI)

A transient, thermal analysis of a two-phase hydrogen heat switch is presented. The heat switch has application to a zero-g, no-moving-part magnetic refrigerator that operates between 7 K and 25 K and provides a one-way thermal path for heat rejection from the refrigerator to the 20 K heat sink. Incorporation of the heat switch is dependent on operating frequency. However, the thermal diode operating characteristic and the high axial thermal conductivity of the heat switch provide advantages over other methods. 3 refs., 13 figs., 2 tabs.

Prenger, C.; Stewart, W.

1990-01-01T23:59:59.000Z

398

Heat reclaimer  

Science Conference Proceedings (OSTI)

A heat reclaimer for the exhaust flue of a heating unit comprises a housing having an air input space, an air output space, and an exhaust space, with a plurality of tubes connected between and communicating the air input space with the air output space and extending through the exhaust space. The exhaust flue of the heating unit is connected into the exhaust space of the housing and an exhaust output is connected to the housing extending from the exhaust space for venting exhaust coming from the heater into the exhaust space to a chimney, for example. A float or level switch is connected to the housing near the bottom of the exhaust space for switching, for example, an alarm if water accumulates in the exhaust space from condensed water vapor in the exhaust. At least one hole is also provided in the housing above the level of the float switch to permit condensed water to leave the exhaust space. The hole is provided in case the float switch clogs with soot. A wiping device may also be provided in the exhaust space for wiping the exterior surfaces of the tubes and removing films of water and soot which might accumulate thereon and reduce their heat transfer capacity.

Bellaff, L.

1981-10-20T23:59:59.000Z

399

heat pump | OpenEI  

Open Energy Info (EERE)

heat pump heat pump Dataset Summary Description View 2010 energy efficiency data from AeroSys Inc, Coaire, Cold Point, First Operations, LG Electronics, Nordyne, and Quietside manufacturers. Data includes cooling capacity, cooling performance, heating capacity, and heating performance. Spreadsheet was created by combining the tables in pdf files that are included in the zip file. Source Energy Applicance Data - United States Federal Trade Commission, www.ftc.gov Date Released Unknown Date Updated Unknown Keywords air conditioner central air conditioner efficiency efficient energy heat pump Data application/vnd.ms-excel icon 2010_CentralAC_All.xls (xls, 82.4 KiB) application/zip icon 2010CentralAirConditioner.zip (zip, 398.2 KiB) Quality Metrics Level of Review Some Review

400

Northeast Home Heating Oil Reserve  

Gasoline and Diesel Fuel Update (EIA)

Northeast Home Heating Oil Reserve Northeast Home Heating Oil Reserve Information on the Northeast Home Heating Oil Reserve is available from the U.S. Department of Energy (DOE) Office of Petroleum Reserves web site at http://www.fossil.energy.gov/programs/reserves/heatingoil/. Northeast Home Heating Oil Reserve (NEHHOR) inventories now classified as ultra-low sulfur distillate (15 parts per million) are not considered to be in the commercial sector and therefore are excluded from distillate fuel oil supply and disposition statistics in Energy Information Administration publications, such as the Weekly Petroleum Status Report, Petroleum Supply Monthly, and This Week In Petroleum. Northeast Home Heating Oil Reserve Terminal Operator Location (Thousand Barrels) Hess Corp. Groton, CT 500*

Note: This page contains sample records for the topic "operating heat rate" 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

Energy Basics: Absorption Heat Pumps  

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

Systems Air-Source Heat Pumps Ductless Mini-Split Heat Pumps Absorption Heat Pumps Geothermal Heat Pumps Supporting Equipment for Heating & Cooling Systems Water Heating...

402

Energy Basics: Geothermal Heat Pumps  

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

Systems Air-Source Heat Pumps Ductless Mini-Split Heat Pumps Absorption Heat Pumps Geothermal Heat Pumps Supporting Equipment for Heating & Cooling Systems Water Heating...

403

Heat pipes for use in a magnetic field  

DOE Patents (OSTI)

A heat pipe configuration is described for use in a magnetic field environment of a fusion reactor. Heat pipes for operation in a magnetic field when liquid metal working fluids are used are optimized by flattening of the heat pipes having an unobstructed annulus which significantly reduces the adverse side region effect of the prior known cylindrically configured heat pipes. The flattened heat pipes operating in a magnetic field can remove 2 to 3 times the heat as a cylindrical heat pipe of the same cross sectional area.

Werner, R.W.; Hoffman, M.A.

1981-04-29T23:59:59.000Z

404

Heat pipes for use in a magnetic field  

DOE Patents (OSTI)

A heat pipe configuration for use in a magnetic field environment of a fusion reactor is disclosed. Heat pipes for operation in a magnetic field when liquid metal working fluids are used are optimized by flattening of the heat pipes having an unobstructed annulus which significantly reduces the adverse side region effect of the prior known cylindrically configured heat pipes. The flattened heat pipes operating in a magnetic field can remove 2--3 times the heat as a cylindrical heat pipe of the same cross sectional area. 4 figs.

Werner, R.W.; Hoffman, M.A.

1983-07-19T23:59:59.000Z

405

Heat pipes for use in a magnetic field  

DOE Patents (OSTI)

A heat pipe configuration for use in a magnetic field environment of a fusion reactor. Heat pipes for operation in a magnetic field when liquid metal working fluids are used are optimized by flattening of the heat pipes having an unobstructed annulus which significantly reduces the adverse side region effect of the prior known cylindrically configured heat pipes. The flattened heat pipes operating in a magnetic field can remove 2--3 times the heat as a cylindrical heat pipe of the same cross sectional area.

Werner, Richard W. (San Ramon, CA); Hoffman, Myron A. (Davis, CA)

1983-01-01T23:59:59.000Z

406

Experimental Study on Energy Efficiency of Heat-source Tower Heat Pump Units in Winter Condition  

Science Conference Proceedings (OSTI)

Building energy consumption in China has been increasing rapidly. And a small increase in the operation efficiency of the air-conditioning system can substantially decrease it. In this paper a new type heat pump is developed to improve the performance ... Keywords: Heat-source tower, Heat pump, Seasonal energy efficiency ratio(SEER), Hermal properties

Li Nianping; Zhang Wenjie; Wang Lijie; Liu Qiuke; Hu Jinhua

2011-01-01T23:59:59.000Z

407

Heat transfer and fluid flow characteristics of microchannels with internal longitudinal fins.  

E-Print Network (OSTI)

??Electronic components generate large amount of heat during their operation, which requires to be dissipated. Over the past decade, internal heat generation levels have exponentially… (more)

Foong, Andrew Jun Li

2009-01-01T23:59:59.000Z

408

Enhanced heat transfer for thermionic power modules  

DOE Green Energy (OSTI)

The thermionic power module is capable of operating at very high heat fluxes, which in turn serve to reduce capital costs. The most efficient operation also requires uniform heat fluxes. The development of enhanced heat transfer systems is required to meet the demand for high heat fluxes (>20 w/cm/sup 2/) at high temperatures (>1500K) which advanced thermionic power modules place upon combustion systems. Energy transfer from the hot combustion gases may take place by convection, radiation, or a combination of radiation and convection. Enhanced convective heat transfer with a jet impingement system has been demonstrated in a thermionic converter. The recently-developed cellular ceramic radiative heat transfer system has also been applied to a thermionic converter. By comparing the jet impingement and cellular ceramic radiative heat transfer systems, an appropriate system may be selected for utilization in advanced thermionic power modules. Results are reported.

Johnson, D.C.

1981-07-01T23:59:59.000Z

409

Heat exchanger with ceramic elements  

DOE Patents (OSTI)

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

Corey, John A. (North Troy, NY)

1986-01-01T23:59:59.000Z

410

Electrochemical cell operation and system  

DOE Patents (OSTI)

Thermal control in fuel cell operation is affected through sensible heat of process gas by providing common input manifolding of the cell gas flow passage in communication with the cell electrolyte and an additional gas flow passage which is isolated from the cell electrolyte and in thermal communication with a heat-generating surface of the cell. Flow level in the cell gas flow passage is selected based on desired output electrical energy and flow level in the additional gas flow passage is selected in accordance with desired cell operating temperature.

Maru, Hansraj C. (Brookfield Center, CT)

1980-03-11T23:59:59.000Z

411

The Impact of Codes, Regulations, and Standards on Split-Unitary Air Conditioners and Heat Pumps, 65,000 Btu/hr and Under  

Science Conference Proceedings (OSTI)

This document establishes a framework for understanding the technology and regulation of split-unitary air conditioners and heat pumps 65,000 Btu/hr and under. The reporting framework is structured so that it can be added to in the future. This study is broken into six chapters:The basic components, refrigeration cycle, operation, and efficiency ratings of split-unitary air conditioners and heat pumps are covered for background information.Equipment efficiency ...

2012-09-21T23:59:59.000Z

412

Operation Terminology  

NLE Websites -- All DOE Office Websites (Extended Search)

Energy Conservation Magnets require a large amount of power to control a particle beam. In order to conserve energy and money when a beam line is down, Operations will install a...

413

Advanced Chemical Heat Pumps Using Liquid-Vapor Reactions  

E-Print Network (OSTI)

Chemical heat pumps utilizing liquid-vapor reactions can be configured in forms analogous to electric drive vapor-compression heat pumps and heat activated absorption heat pumps. Basic thermodynamic considerations eliminate some heat pumps and place restrictive working fluid requirements on others, but two thermodynamically feasible systems have significant potential advantage over conventional technology. An electric drive reactive heat pump can use smaller heat exchangers and compressor than a vapor-compression machine, and have more flexible operating characteristics. A waste heat driven heat pump (temperature amplifier) using liquid-vapor chemical reactions- can operate with higher coefficient of performance and smaller heat exchangers than an absorption temperature amplifying heat pump. Higher temperatures and larger temperature lifts should also be possible.

Kirol, L.

1987-09-01T23:59:59.000Z

414

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

415

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 G. (Winchester, MA)

1993-01-01T23:59:59.000Z

416

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

417

Definition: Ground Source Heat Pumps | Open Energy Information  

Open Energy Info (EERE)

Pumps Pumps Jump to: navigation, search Dictionary.png Ground Source Heat Pumps A Ground Source Heat Pump is a central building heating and/or cooling system that takes advantage of the relatively constant year-round ground temperature to pump heat to or from the ground.[1][2][3] View on Wikipedia Wikipedia Definition A geothermal heat pump or ground source heat pump (GSHP) is a central heating and/or cooling system that pumps heat to or from the ground. It uses the earth as a heat source (in the winter) or a heat sink (in the summer). This design takes advantage of the moderate temperatures in the ground to boost efficiency and reduce the operational costs of heating and cooling systems, and may be combined with solar heating to form a geosolar system with even greater efficiency. Ground source heat pumps

418

Sonoma State Hospital, Eldridge, California, geothermal-heating system: conceptual design and economic feasibility report  

DOE Green Energy (OSTI)

The Sonoma State Mental Hospital, located in Eldridge, California, is presently equipped with a central gas-fired steam system that meets the space heating, domestic hot water, and other heating needs of the hospital. This system is a major consumer of natural gas - estimated at 259,994,000 cubic feet per year under average conditions. At the 1981 unit gas rate of $0.4608 per therm, an average of $1,258,000 per year is required to operate the steam heating system. The hospital is located in an area with considerable geothermal resources as evidenced by a number of nearby hot springs resorts. A private developer is currently investigating the feasibility of utilizing geothermally heated steam to generate electricity for sale to the Pacific Gas and Electric Company. The developer has proposed to sell the byproduct condensed steam to the hospital, which would use the heat energy remaining in the condensate for its own heating needs and thereby reduce the fossil fuel energy demand of the existing steam heating system. The geothermal heating system developed is capable of displacing an estimated 70 percent of the existing natural gas consumption of the steam heating system. Construction of the geothermal fluid distribution and collection system and the retrofits required within the buildings are estimated to cost $1,777,000. Annual expenses (operation and maintenance, insurance, and geothermal fluid purchase) have been estimated to be $40,380 per year in 1981 dollars. The proposed geothermal heating system could then be completely paid for in 32 months by the savings in natural gas purchases that would result.

Not Available

1982-02-01T23:59:59.000Z

419

Heat Exchangers  

Science Conference Proceedings (OSTI)

Table 16   Ceramic heat exchanger systems...Soaking pit 870â??1230 1600â??2250 Fe, Si, alkalis Solar Turbines â?¦ 4â??8 OD Ã? 180 long (440 tubes) Aluminum melt furnaces 1010 1850 Alkali salts Plate fin GTE 0.6, 1.6 25â??46 Multiple 870â??1370 1600â??2250 Clean (good), alkalis (poor) Coors 0.25, 1.0 30 Ã? 30 Ã? 46 Multiple Clean (good), alkalis (poor) Radiant...

420

Electrically heated liquid tank employing heat pipe heat transfer means  

SciTech Connect

The heating apparatus for applying heat to the interior of a chamber includes a modular, removable, electrical, heat-producing unit and a heat pipe mountable in a wall of the chamber with one end of the pipe arranged to receive heat from the electrical heat producing unit exterior of the housing and with another end of the pipe constructed and arranged to apply heat to the medium within the chamber. The heat pipe has high conductivity with a low temperature differential between the ends thereof and the heat producing unit includes an electric coil positioned about and removably secured to the one end of the heat pipe. The electric coil is embedded in a high thermal conducitivity, low electrical conductivity filler material which is surrounded by a low thermal conductivity insulating jacket and which is received around a metal core member which is removably secured to the one end of the heat pipe.

Shutt, J.R.

1978-12-26T23:59:59.000Z

Note: This page contains sample records for the topic "operating heat rate" 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

Multi-Source Hydronic Heat Pump System Performance Test Bed  

E-Print Network (OSTI)

An extensive independent evaluation recently was completed of the Multi-Source Hydronic Heat Pump (MSHHP) system, a proprietary heating, ventilating and air conditioning (HVAC) system developed by Meckler Systems Group. The MSHHP tests were conducted on a unique test bed designed and constructed by National Technical Systems (NTS) through a research and development grant program funded by Southern California Edison Company. This paper outlines testing methods and results, including evaluations of peak power and energy savings allowed by the innovative system. The main difference between the MSHHP and a conventional HVAC system is use of a chilled water "diversity" cooling loop interconnecting air to water coils (located at each water source heat pump unit) with a central chilled water storage tank. The MSHHP system uses significantly less energy than a conventional HVAC system, and lowers peak demand by shifting required electrical energy consumption to lower-cost, off-peak and mid-peak rates. Lower heat pump capacities are a main feature of the MSHHP. This is accomplished by pre-cooling return air from the zone space, a process that also allows the heat pump to operate at a higher Coefficient of Performance (COP), thereby contributing to further energy savings.

Meckler, M.

1984-01-01T23:59:59.000Z

422

High Water Heating Bills on Lockdown at Idaho Jail | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

High Water Heating Bills on Lockdown at Idaho Jail High Water Heating Bills on Lockdown at Idaho Jail High Water Heating Bills on Lockdown at Idaho Jail August 19, 2010 - 12:05pm Addthis The Blaine County Public Safety Facility houses between 60 and 80 prisoners and roughly 30 staffers. | Photo courtesy of Blaine The Blaine County Public Safety Facility houses between 60 and 80 prisoners and roughly 30 staffers. | Photo courtesy of Blaine Lindsay Gsell What does this project do? The new solar thermal hot water system will provide nearly 70 percent of the BTUs required for heating 600,000 gallons of water for the jail annually, saving the county more than $4,000 a year in electricity costs at current rates. In Hailey, Idaho, one 330,000 square foot building - the Blaine County Public Safety Facility - accounts for the county's highest operational

423

Heat and mass transfer in a falling film absorber of ammonia-water absorption systems  

SciTech Connect

For ammonia-water generator-absorber heat exchanger (GAX) systems to work at high coefficient of performance, the heat and mass transfer components have to operate at optimum performance within a narrow range of conditions for the recovery of internal energy. In the present work, an analysis is performed to study the absorption process of an ammonia-water vapor mixture by an aqueous solution of ammonia in a falling film absorber. The combined heat and mass transfer processes involved are analyzed through an integral formulation of the continuity, momentum, energy, and diffusion equations. The effects of vapor flow direction relative to the solution, cooling ability, ammonia concentration of solution and vapor, and interfacial momentum and heat transfer rate on absorption processes are investigated. The characteristics of the absorption process are found to be governed by the relative significance of the mass transfer resistance and the driving forces between the solution film and the vapor mixture.

Kim, B. [Hongik Univ., Seoul (Korea, Republic of). Dept. of Mechanical Engineering

1998-07-01T23:59:59.000Z

424

Convective heat transfer in the laminar-turbulent transition region with molten salt in a circular tube  

SciTech Connect

In order to understand the heat transfer characteristics of molten salt and testify the validity of the well-known empirical convective heat transfer correlations, experimental study on transition convective heat transfer with molten salt in a circular tube was conducted. Molten salt circulations were realized and operated in a specially designed system over 1000 h. The average forced convective heat transfer coefficients of molten salt were determined by least-squares method based on the measured data of flow rates and temperatures. Finally, a heat transfer correlation of transition flow with molten salt in a circular tube was obtained and good agreement was observed between the experimental data of molten salt and the well-known correlations presented by Hausen and Gnielinski, respectively. (author)

Yu-ting, Wu; Bin, Liu; Chong-fang, Ma; Hang, Guo [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education and Key Laboratory of Heat Transfer and Energy Conversion, Beijing municipality, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100022 (China)

2009-10-15T23:59:59.000Z

425

Solar heat collector  

SciTech Connect

A solar heat collector comprises an evacuated transparent pipe; a solar heat collection plate disposed in the transparent pipe; a heat pipe, disposed in the transparent pipe so as to contact with the solar heat collection plate, and containing an evaporable working liquid therein; a heat medium pipe containing a heat medium to be heated; a heat releasing member extending along the axis of the heat medium pipe and having thin fin portions extending from the axis to the inner surface of the heat medium pipe; and a cylindrical casing surrounding coaxially the heat medium pipe to provide an annular space which communicates with the heat pipe. The evaporable working liquid evaporates, receiving solar heat collected by the heat collection plate. The resultant vapor heats the heat medium through the heat medium pipe and the heat releasing member.

Yamamoto, T.; Imani, K.; Sumida, I.; Tsukamoto, M.; Watahiki, N.

1984-04-03T23:59:59.000Z

426

Heat pump system with selective space cooling  

DOE Patents (OSTI)

A reversible heat pump provides multiple heating and cooling modes and includes a compressor, an evaporator and heat exchanger all interconnected and charged with refrigerant fluid. The heat exchanger includes tanks connected in series to the water supply and a condenser feed line with heat transfer sections connected in counterflow relationship. The heat pump has an accumulator and suction line for the refrigerant fluid upstream of the compressor. Sub-cool transfer tubes associated with the accumulator/suction line reclaim a portion of the heat from the heat exchanger. A reversing valve switches between heating/cooling modes. A first bypass is operative to direct the refrigerant fluid around the sub-cool transfer tubes in the space cooling only mode and during which an expansion valve is utilized upstream of the evaporator/indoor coil. A second bypass is provided around the expansion valve. A programmable microprocessor activates the first bypass in the cooling only mode and deactivates the second bypass, and vice-versa in the multiple heating modes for said heat exchanger. In the heating modes, the evaporator may include an auxiliary outdoor coil for direct supplemental heat dissipation into ambient air. In the multiple heating modes, the condensed refrigerant fluid is regulated by a flow control valve. 4 figs.

Pendergrass, J.C.

1997-05-13T23:59:59.000Z

427

Heat pump system with selective space cooling  

DOE Patents (OSTI)

A reversible heat pump provides multiple heating and cooling modes and includes a compressor, an evaporator and heat exchanger all interconnected and charged with refrigerant fluid. The heat exchanger includes tanks connected in series to the water supply and a condenser feed line with heat transfer sections connected in counterflow relationship. The heat pump has an accumulator and suction line for the refrigerant fluid upstream of the compressor. Sub-cool transfer tubes associated with the accumulator/suction line reclaim a portion of the heat from the heat exchanger. A reversing valve switches between heating/cooling modes. A first bypass is operative to direct the refrigerant fluid around the sub-cool transfer tubes in the space cooling only mode and during which an expansion valve is utilized upstream of the evaporator/indoor coil. A second bypass is provided around the expansion valve. A programmable microprocessor activates the first bypass in the cooling only mode and deactivates the second bypass, and vice-versa in the multiple heating modes for said heat exchanger. In the heating modes, the evaporator may include an auxiliary outdoor coil for direct supplemental heat dissipation into ambient air. In the multiple heating modes, the condensed refrigerant fluid is regulated by a flow control valve.

Pendergrass, Joseph C. (Gainesville, GA)

1997-01-01T23:59:59.000Z

428

Experimental Research of Air Source Heat Pump Frosting and Defrosting in a Double Stage-Coupling Heat Pump  

E-Print Network (OSTI)

In a double stage-coupling heat pump, comprising an air source and water loop heat pump, the 13~20 ? low temperature water is supplied to the water loop heat pump unit. The water loop heat pump can extract heat from the water and heat the indoor air. The most common method of air source heat pump frost removal is reverse-cycle defrost. During the defrosting operation, the heat pump runs in the cooling mode. The defrost process is accomplished by reversing the normal heating mode. In this paper, the effect of the heat storage tank to the air source heat pump defrosting is test. Owing to the existence of the heat storage tank, thermal inertia of the loop is relatively high. The frosting and defrosting course of the air source heat pump have little effect on the room temperature.

Wang, Z.; Gu, J.; Lu, Z.

2006-01-01T23:59:59.000Z

429

Geothermal district heating systems  

DOE Green Energy (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

430

Xenon Recirculation-Purification with a Heat Exchanger  

E-Print Network (OSTI)

Liquid-xenon based particle detectors have been dramatically growing in size during the last years, and are now exceeding the one-ton scale. The required high xenon purity is usually achieved by continuous recirculation of xenon gas through a high-temperature getter. This challenges the traditional way of cooling these large detectors, since in a thermally well insulated detector, most of the cooling power is spent to compensate losses from recirculation. The phase change during recondensing requires five times more cooling power than cooling the gas from ambient temperature to -100C (173 K). Thus, to reduce the cooling power requirements for large detectors, we propose to use the heat from the purified incoming gas to evaporate the outgoing xenon gas, by means of a heat exchanger. Generally, a heat exchanger would appear to be only of very limited use, since evaporation and liquefaction occur at zero temperature difference. However, the use of a recirculation pump reduces the pressure of the extracted liquid, forces it to evaporate, and thus cools it down. We show that this temperature difference can be used for an efficient heat exchange process. We investigate the use of a commercial parallel plate heat exchanger with a small liquid xenon detector. Although we expected to be limited by the available cooling power to flow rates of about 2 SLPM, rates in excess of 12 SLPM can easily be sustained, limited only by the pump speed and the impedance of the flow loop. The heat exchanger operates with an efficiency of (96.8 +/- 0.5)%. This opens the possibility for fast xenon gas recirculation in large-scale experiments, while minimizing thermal losses.

K. L. Giboni; E. Aprile; B. Choi; T. Haruyama; R. F. Lang; K. E. Lim; A. J. Melgarejo; G. Plante

2011-03-04T23:59:59.000Z

431

Waste heat boiler with feed mixing nozzle  

SciTech Connect

A waste heat boiler of the type which is particularly suited for use in marine applications and which incorporates a feed mixing nozzle that is operative for purposes of effecting, by utilizing steam taken from the steam generating bank, a preheating of the feedwater that is fed to the steam drum. In addition to the aforesaid feed mixing nozzle, the subject waste heat boiler includes a feedwater control valve, a steam drum, a circulation pump, a steam generating bank and a centrifugal water separator. The feedwater control valve is employed to modulate the flow rate of the incoming feedwater in order to maintain the desired level of water in the steam drum. In turn the latter steam drum is intended to function in the manner of a reservoir for the circulating water that through the operation of the circulating pump is supplied to the steam generating bank. The circulating water which is supplied to the steam generating bank is heated therein to saturation temperature, and steam is generated thus. A water-steam mixture is returned from the steam generating bank to the steam drum and is directed into the centrifugal water separator that is suitably located within the steam drum. It is in the centrifugal water separator that the separation of the water-steam mixture is effected such that water is returned to the lower portion of the steam drum and the steam is supplied to the upper portion of the steam drum. The preheating of the feedwater is accomplished by directing the incoming feedwater through an internal feed pipe to the mixing nozzle, the latter being positioned in the line through which the water-steam mixture is returned to the steam drum.

Mastronarde, Th.P.

1984-05-01T23:59:59.000Z

432

Sensible and Latent Heat Flux Measurements over the Ocean  

Science Conference Proceedings (OSTI)

This papar presents an extensive act of sensible heat (Reynolds flux and dissipation methods) and latent heat (dissipation method) flux measurements from a stable deep water tower and from ships on the deep sea. Operational difficulties ...

W. G. Large; S. Pond

1982-05-01T23:59:59.000Z

433

Nuclear Maintenance Applications Center: Heat Exchanger Maintenance Guide  

Science Conference Proceedings (OSTI)

This guide provides plant personnel with information on the operation, maintenance, and performance of heat exchangers. The contents of this guide will assist plant personnel in improving heat exchanger reliability, performance, and maintenance practices.

2009-06-14T23:59:59.000Z

434

Control system for electric water heater with heat pump external heat source  

Science Conference Proceedings (OSTI)

A control system for an electric water heater operatively associated with an external heat source, such as a heat pump. The water heater includes a water storage tank provided with an electric tank heating unit having a tank thermostat which closes in response to water temperature in the tank, allowing a flow of current through the tank heating unit so as to turn it on to heat the water, and which opens when the tank thermostat has been satisfied, interrupting the current flow so as to turn the tank heating unit off. The control system as responsive to the initial current surge through the tank heating unit when the tank thermostat closes to interrupt the current flow to the tank heating unit so as to maintain the heating unit off and to turn on the external heat source and maintain it on until the tank thermostat opens. The initial current surge cleans the contacts of the tank thermostat by burning off any insulating oxide residues which may have formed on them. The control system includes means responsive to abnormal conditions which would prevent the external heat source from heating water effectively for turning off the external heat source and turning on the tank heating unit and maintaining the external heat source off and the tank heating unit on until the tank thermostat is satisfied.

Shaffer Jr., J. E.; Picarello, J. F.

1985-09-10T23:59:59.000Z

435

Energy Basics: Radiant Heating  

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

very low heat capacity and have the quickest response time of any heating technology. More Information Visit the Energy Saver website for more information about radiant heating...

436

Energy Basics: Radiant Heating  

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

low heat capacity and have the quickest response time of any heating technology. More Information Visit the Energy Saver website for more information about radiant heating in homes...

437

Heat pump system  

DOE Patents (OSTI)

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

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

1982-01-01T23:59:59.000Z

438

Heat pump system  

DOE Patents (OSTI)

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

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

1979-01-01T23:59:59.000Z

439

Simulation of tokamak SOL and divertor region including heat flux mitigation by gas puffing  

Science Conference Proceedings (OSTI)

Two-dimensional (2D), scrape-off layer (SOL)-divertor transport simulations are performed using the integrated plasma-neutral-impurity code KTRAN developed at Seoul National University. Firstly, the code is applied to reproduce a National Spherical Torus eXperiment (NSTX) discharge by using the prescribed transport coefficients and the boundary conditions obtained from the experiment. The plasma density, the heat flux on the divertor plate, and the D (alpha) emission rate profiles from the numerical simulation are found to follow experimental trends qualitatively. Secondly, predictive simulations are carried out for the baseline operation mode in Korea Superconducting Tokamak Advanced Research (KSTAR) to predict the heat flux on the divertor target plates. The stationary peak heat flux in the KSTAR baseline operation mode is expected to be 6.5 MW/m(2) in the case of an orthogonal divertor. To study the mitigation of the heat flux, we investigated the puffing effects of deuterium and argon gases. The puffing position is assumed to be in front of the strike point at the outer lower divertor plate. In the simulations, mitigation of the peak heat flux at the divertor target plates is found to occur when the gas puffing rate exceeds certain values, similar to 1.0 x 10(20) /s and similar to 5.0 x 10(18) /s for deuterium and argon, respectively. Multi-charged impurity transport is also investigated for both NSTX and KSTAR SOL and divertor regions.

Park, Jin Woo [Seoul National University, Seoul, S. Korea; Na, Y. S. [Seoul National University, Seoul, S. Korea; Hong, S. H. [National Fusion Research Institute, Daejon, South Korea; Ahn, J.W. [Oak Ridge National Laboratory (ORNL); Kim, D. K. [Agency Def Dev, Taejon, South Korea; Han, Hyunsun [National Fusion Research Institute, Taejon, South Korea; Shim, Seong Bo [Pusan National University, Busan, Korea; Lee, Hae June [Pusan National University, Busan, Korea

2012-01-01T23:59:59.000Z

440

Scoping heat transfer analysis of a completely-blocked Type-Q septifoil  

Science Conference Proceedings (OSTI)

Heat removal mechanisms for a completely-blocked Type-Q (new design) septifoil situated in an otherwise normally operating K-reactor are investigated in this report. The best-estimate maximum septifoil heat generation rate for a 26.2{degrees}C cooling water inlet temperature is 119 to 141 kW depending on the counter-current flow limitation correlation chosen. The corresponding reactor powers are 648 and 768 MW or 27 and 32% of 2400 MW (historical annual averaged full power). These estimates are based on a steady-state scoping analysis and have a large uncertainty.

Flach, G.P.

1991-12-01T23:59:59.000Z

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to obtain the most current and comprehensive results.


441

Geothermal Energy: Residential Space Heating  

DOE Green Energy (OSTI)

The purpose of this study, which was carried out under the auspices of the DGRST, was to determine the best way to use geothermal hot water for residential space heating. It quickly became apparent that the type of heating apparatus used in the housing units was most important and that heat pumps could be a valuable asset, making it possible to extract even more geothermal heat and thus substantially improve the cost benefit of the systems. Many factors play a significant role in this problem. Therefore, after a first stage devoted to analyzing the problem through a manual method which proved quite useful, the systematic consideration of all important aspects led us to use a computer to optimize solutions and process a large number of cases. The software used for this general study can also be used to work out particular cases: it is now available to any interested party through DGRST. This program makes it possible to: (1) take climatic conditions into account in a very detailed manner, including temperatures as well as insolation. 864 cases corresponding to 36 typical days divided into 24 hours each were chosen to represent the heating season. They make it possible to define the heating needs of any type of housing unit. (2) simulate and analyze the behavior in practice of a geothermal heating system when heat is extracted from the well by a simple heat exchanger. This simulation makes it possible to evaluate the respective qualities of various types of heating apparatus which can be used in homes. It also makes it possible to define the best control systems for the central system and substations and to assess quite accurately the presence of terminal controls, such as radiators with thermostatically controlled valves. (3) determine to what extent the addition of a heat pump makes it possible to improve the cost benefit of geothermal heating. When its average characteristics and heating use conditions (price, coefficient of performance, length of utilization, electrical rates, etc.) are taken into account, the heat pump should not be scaled for maximum heating power. Consequently, the program considers several possible sizes, with different installation schemes, and selects for each case the value which corresponds to the lowest cost of heating.

None

1977-03-01T23:59:59.000Z

442

Cogeneration Operational Issues  

E-Print Network (OSTI)

A great deal of the discussions concerning congeneration projects are focused on the "avoided cost" and other legal issues which effect these projects. These areas are extremely important and are essential to the success of the venture. Equally important, however, are the operational Issues which impact the utility and the cogenerator. This paper addresses the utility perspective in regard to possible impact of cogeneration systems on utility service to other customer, safety and substation operations. Other operational issues also include utility transmission planning, generation planning and fuel mix decisions. All of these operational problems have an impact on the ratepayer in regard to quality of electric service and future rates. Both the cogenerator and the utility have an interest in solving these problems.

Williams, M.

1985-05-01T23:59:59.000Z

443

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

444

Rates and Repayment Services  

NLE Websites -- All DOE Office Websites (Extended Search)

Customer Letter - Preliminary Review of Drought Adder Component for 2011 Firm Power Rates 2010 Rates and Rate Schedule - Current * 2009 Rates and Rate Schedule 2008 Rates and...

445

Efficiency of unitary heat pumps  

SciTech Connect

The efficiencies of approximately 500 unitary heat pumps, from 30 different manufacturers, certified by the Air Conditioning and Refrigeration Institute (ARI) were examined. The certified units account for about 90% of all unitary heat pumps manufactured in the U.S. with a rated cooling capacity below 135,000 Btu/hr, and thus represent a comprehensive data file of the efficiencies of unitary heat pumps offered for sale in the U.S. A computer was used to group the heat pumps according to type and capacity, and to calculate their coefficients of performance (COP) using the data contained in ARI current Directory (April 1 to July 31, 1973) of Certified Unitary Heat Pumps. The results show that the COP of the heat pumps varied from a low of 1.5 to a high of 3.15 or a factor of 2 between the lowest and the highest efficiency, and that the average COP was 2.1 in cooling and 2.4 in heating. The variations of COP with heat pump size, type, manufacturer and outdoor temperature are presented.

Nwude, J.K.; Roman, A.J.

1973-11-01T23:59:59.000Z

446

Heating systems for heating subsurface formations  

Science Conference Proceedings (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

447

Handbook of heat and mass transfer. Volume 1  

Science Conference Proceedings (OSTI)

This two-volume series, the work of more than 100 contributors, presents advanced topics in industrial heat and mass transfer operations and reactor design technology. Volume 1 emphasizes heat transfer operations. The contents are: Fundamentsls of momentum and heat transfer. Scaling in laminar and turbulent heat and mass transfer. Heat flux in the Benar-Rayleigh problem. Hydrodynamics of free liquid jets and their influence on heat transfer. Natural convection heat transfer to power law fluids. Natural convection in evaporating droplets. Principles of heat and mass transfer with liquid evaporation. Bubble nucleation, growth, and departure in boiling heat transfer. Forced convection boiling in uniformly heated channels. Transient boiling heat transfer under forced convection. Prediction of heat transfer during forced convection subcooled boiling. Liquid metal heat transfer in turbulent pipe flows. Mixed convection in buoyant plumes. Nucleation and growth in the diffusion cloud chamber. Convective and radiative heat transfer of flowing gaseous-solid suspensions. Heat transfer in gas-solid fluidized beds. Gas convection and unsteady conduction in fluid bed heat transfer. Heat transfer between tubes and gas-solid fluid beds. Periodic heat transfer through inhomogeneous layers.

Cheremisinoff, N.P.

1986-01-01T23:59:59.000Z

448

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

449

Modeling and Simulation of the ITER First Wall/Blanket Primary Heat Transfer System  

SciTech Connect

ITER inductive power operation is modeled and simulated using a thermal-hydraulics system code (RELAP5) integrated with a 3-D CFD (SC-Tetra) code. The Primary Heat Transfer System (PHTS) functions are predicted together with the main parameters operational ranges. The control algorithm strategy and derivation are summarized as well. The First Wall and Blanket modules are the primary components of PHTS, used to remove the major part of the thermal heat from the plasma. The modules represent a set of flow channels in solid metal structure that serve to absorb the radiation heat and nuclear heating from the fusion reactions and to provide shield for the vacuum vessel. The blanket modules are water cooled. The cooling is forced convective with constant blanket inlet temperature and mass flow rate. Three independent water loops supply coolant to the three blanket sectors. The main equipment of each loop consists of a pump, a steam pressurizer and a heat exchanger. A major feature of ITER is the pulsed operation. The plasma does not burn continuously, but on intervals with large periods of no power between them. This specific feature causes design challenges to accommodate the thermal expansion of the coolant during the pulse period and requires active temperature control to maintain a constant blanket inlet temperature.

Ying, Alice [University of California, Los Angeles; Popov, Emilian L [ORNL

2011-01-01T23:59:59.000Z

450

Test results of a Stirling engine utilizing heat exchanger modules with an integral heat pipe  

SciTech Connect

The Heat Pipe Stirling Engine (HP-1000), a free-piston Stirling engine incorporating three heat exchanger modules, each having a sodium filled heat pipe, has been tested at the NASA-Lewis Research Center as part of the Civil Space Technology Initiative (CSTI). The heat exchanger modules were designed to reduce the number of potential flow leak paths in the heat exchanger assembly and incorporate a heat pipe as the link between the heat source and the engine. An existing RE-1000 free-piston Stirling engine was modified to operate using the heat exchanger modules. This paper describes heat exchanger module and engine performance during baseline testing. Condenser temperature profiles, brake power, and efficiency are presented and discussed.

Skupinski, R.C.; Tower, L.K.; Madi, F.J.; Brusk, K.D.

1993-04-01T23:59:59.000Z

451

New and Existing Buildings Heating and Cooling Opportunities: Dedicated Heat Recovery Chiller  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Langfitt Langfitt U S Department of State Overseas Buildings Operations Mechanical Engineering Division *Engineers are working Harder AND Smarter *New Energy Economy *Heating Is Where The Opportunity Is  39% of total US energy goes into non-residential buildings.  Gas for heating is about 60% of energy used in a building  Gas for heating is at least 25% of total energy used in the US. Heat Generation System Heat Disposal System What's Wrong With This Picture? Keep the heat IN the system Don't run main plant equipment until necessary ! Less rejected heat Less gas consumption High Temp >160F with conventional boilers Hydronic heating... condensing style modular boilers. The entire heating system... designed for low temperature water, recommend maximum temperature of 135ºF.