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1

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

E-Print Network [OSTI]

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

2

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.

. Aksak; S. Turgut

2011-04-14T23:59:59.000Z

3

Combined Retrieval, Microphysical Retrievals and Heating Rates  

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

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

Feng, Zhe

4

Combined Retrieval, Microphysical Retrievals and Heating Rates  

SciTech Connect (OSTI)

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

Feng, Zhe

2013-02-22T23:59:59.000Z

5

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

6

Focused cathode design to reduce anode heating during vircator operation  

SciTech Connect (OSTI)

Virtual cathode oscillators, or vircators, are a type of high power microwave device which operates based on the instability of a virtual cathode, or cloud of electrons, which forms when electron current injected into the drift tube exceeds the space charge limited current within the drift tube. Anode heating by the electron beam during vircator operation ultimately limits achievable pulse lengths, repetition rates, and the duration of burst mode operation. This article discusses a novel cathode design that focuses electrons through holes in the anode, thus significantly reducing anode heating by the electrons emitted from the cathode during the first transit through the A-K gap. Reflexing electrons continue to deposit energy on the anode; however, the discussed minimization of anode heating by main beam electrons has the potential to enable higher repetition rates as well as efficiency and longer diode lifetime. A simulation study of this type of cathode design illustrates possible advantages.

Lynn, Curtis F.; Dickens, James C.; Neuber, Andreas A. [Center for Pulsed Power and Power Electronics, Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, Texas 79409 (United States)] [Center for Pulsed Power and Power Electronics, Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, Texas 79409 (United States)

2013-10-15T23:59:59.000Z

7

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

8

Standby Rates for Combined Heat and Power Systems  

SciTech Connect (OSTI)

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

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

2014-02-01T23:59:59.000Z

9

Resistive Wall Heating of the Undulator in High Repetition Rate  

SciTech Connect (OSTI)

In next generation high repetition rate FELs, beam energy loss due to resistive wall wakefields will produce significant amount of heat. The heat load for a superconducting undulator (operating at low temperature), must be removed and will be expensive to remove. In this paper, we study this effect in an undulator proposed for a Next Generation Light Source (NGLS) at LBNL. We benchmark our calculations with measurements at the LCLS and carry out detailed parameter studies using beam from a start-to-end simulation. Our preliminarym results suggest that the heat load in the undulator is about 2 W/m or lower with an aperture size of 6 mm for nominal NGLS preliminary design parameters.

Qiang, J; Corlett, J; Emma, P; Wu, J

2012-05-20T23:59:59.000Z

10

TEMPERED OPERATORS AND THE HEAT KERNEL AND COMPLEX POWERS OF ELLIPTIC PSEUDODIFFERENTIAL OPERATORS  

E-Print Network [OSTI]

TEMPERED OPERATORS AND THE HEAT KERNEL AND COMPLEX POWERS OF ELLIPTIC PSEUDODIFFERENTIAL OPERATORS operator and complex powers of b-pseudodi#27;erential operators, as the heat operator and complex powers are the Laplace and Mellin transforms, respectively, of the resolvent. The heat operator and complex powers

Loya, Paul

11

Fabrication and heating rate study of microscopic surface electrode ion traps  

E-Print Network [OSTI]

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

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

2010-09-15T23:59:59.000Z

12

Control and optimal operation of simple heat pump cycles  

E-Print Network [OSTI]

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

Skogestad, Sigurd

13

Hot Water Heating System Operation and Energy Conservation  

E-Print Network [OSTI]

Based on an example of the reconstruction of a hot water heating system, this paper provides an analysis and comparison of the operations of hot water heating systems, including supply water temperature adjustment, flow adjustment during each...

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

2006-01-01T23:59:59.000Z

14

E-Print Network 3.0 - as-operated heat loss Sample Search Results  

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

((svsv: Kylteknik): Kylteknik) 424503 E424503 E 20102010 88 --rzrz 8.8. Heat pumps, heat pipes,Heat pumps, heat pipes, Summary: heat transfer capacity and rate...

15

Optimization of the Heating System Operation  

E-Print Network [OSTI]

on the basis of the variation of outdoor temperature, and in this way, the heating system can be optimized....

Xu, W.; Mao, S.

2006-01-01T23:59:59.000Z

16

Heat Release Rates | Department of Energy  

Office of Environmental Management (EM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "of EnergyEnergyENERGY TAX POLICIES7.pdfFuel Celland Contractors |DOCUMENT RELEASEHave0-1Heat Pump SystemHeat

17

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

E-Print Network [OSTI]

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

Bergles A. E.

1962-01-01T23:59:59.000Z

18

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

E-Print Network [OSTI]

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

Carrascal, Luis M.

19

Simplified motional heating rate measurements of trapped ions  

E-Print Network [OSTI]

We have measured motional heating rates of trapped atomic ions, a factor that can influence multi-ion quantum logic gate fidelities. Two simplified techniques were developed for this purpose: one relies on Raman sideband detection implemented with a single laser source, while the second is even simpler and is based on time-resolved fluorescence detection during Doppler recooling. We applied these methods to determine heating rates in a microfrabricated surface-electrode trap made of gold on fused quartz, which traps ions 40 microns above its surface. Heating rates obtained from the two techniques were found to be in reasonable agreement. In addition, the trap gives rise to a heating rate of 300 plus or minus 30 per second for a motional frequency of 5.25 MHz, substantially below the trend observed in other traps.

Epstein, R J; Leibfried, D; Wesenberg, J H; Bollinger, J J; Amini, J M; Blakestad, R B; Britton, J; Home, J P; Itano, W M; Jost, J D; Knill, E; Langer, C; Ozeri, R; Shiga, N; Wineland, D J

2007-01-01T23:59:59.000Z

20

Aspects of coal pyrogenation with high heating rates  

SciTech Connect (OSTI)

The present paper describes the conversion of different rank coals into coke of required quality, influenced by heating rate variation. The study has been made for romanian coals and the imported coals too. Theoretical aspects of the coking process kinetics with special practical applications are shown. In Romania, classical coke making technology involves some theoretical and practical problems because of the local coal supply, weak in coking coals. Petrographical methods, as a complementary source of information for coking mechanisms understanding were used, for blends with high content of weakly coking coals. The results reveal the importance of rank and petrographical composition determinations for complex blends making. The paper continues previous studies of coke making kinetics, influenced by heating rate variation. On the basis of the relationship between coal charge composition and coke structure, including its use in the blast furnace, the influence of an increase in heating rate on the structure of the coke produced from different rank and petrographical composition coals, was studied. The heating rates ranged between 3 and 40 C/min. The structural changes produced during pyrogenation were more evident for the heating rates: 3, 6, 10 and 40 C/min. Table 2 reveals the optical aspects of coke matrix and inertinitic inclusions evolution, that is, the differences in structure arrangement by changing the plastic phase characteristics due to the increase in the heating rate.

Panaitescu, C.; Barca, F. [Politehnica Univ., Bucharest (Romania); Predeanu, G.; Albastroiu, P. [Metallurgical Research Inst., Bucharest (Romania)

1994-12-31T23:59:59.000Z

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.


21

Property:HeatRate | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy ResourcesLoadingPenobscot County, Maine:PlugNumberOfArraProjectTypeTopic2GrossGen JumpRating Jump

22

7-106 A reversible heat pump is considered. The temperature of the source and the rate of heat transfer to the sink are to be determined.  

E-Print Network [OSTI]

7-39 7-106 A reversible heat pump is considered. The temperature of the source and the rate of heat transfer to the sink are to be determined. Assumptions The heat pump operates steadily. Analysis Combining.5¸ ¹ · ¨ © § ¸ ¸ ¹ · ¨ ¨ © § 1.6 1 1)K300( COP 1 1 maxHP, HL TT Based upon the definition of the heat pump coefficient

Bahrami, Majid

23

Convergence Rates with Inexact Nonexpansive Operators  

E-Print Network [OSTI]

Apr 18, 2014 ... Abstract: In this paper, we present a convergence rate analysis for the inexact Krasnosel'ski{\\u{\\i}}-Mann iteration built from nonexpansive...

Jingwei Liang

2014-04-18T23:59:59.000Z

24

Inverse bremsstrahlung heating rate for dense plasmas in laser fields  

SciTech Connect (OSTI)

We report a theoretical analysis of inverse bremsstrahlung heating rate in the eikonal approximation. The present analysis is performed for a dense plasma using the screened electron-ion interaction potential for the ion charge state Z{sub i} = 1 and for both the weak and strong plasma screening cases. We have also compared the eikonal results with the first Born approximation (FBA) [M. Moll et al., New J. Phys. 14, 065010 (2012)] calculation. We find that the magnitudes of inverse bremsstrahlung heating rate within the eikonal approximation (EA) are larger than the FBA values in the weak screening case (? = 0.03 a.u.) in a wide range of field strength for three different initial electron momenta (2, 3, and 4 a.u.). But for strong screening case (? = 0.3 a.u.), the heating rates predicted by the two approximations do not differ much after reaching their maximum values. Furthermore, the individual contribution of photoemission and photoabsorption processes to heating rate is analysed for both the weak and strong screening cases. We find that the single photoemission and photoabsorption rates are the same throughout the field strength while the multiphoton absorption process dominates over the multiphoton emission process beyond the field strength ? 410{sup 8} V/cm. The present study of the dependence of heating rate on the screening parameter ranging from 0.01 to 20 shows that whereas the heating rate predicted by the EA is greater than the FBA up to the screening parameter ? = 0.3 a.u., the two approximation methods yield results which are nearly identical beyond the above value.

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

2013-07-15T23:59:59.000Z

25

Cooling rate, heating rate, and aging effects in glassy water Nicolas Giovambattista,1  

E-Print Network [OSTI]

be glassified by cooling using hyper- quenching techniques (i.e., with rates of the order of 105 K/s [8Cooling rate, heating rate, and aging effects in glassy water Nicolas Giovambattista,1 H. Eugene of water molecules during the process of generating a glass by cooling, and during the process

Sciortino, Francesco

26

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

E-Print Network [OSTI]

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

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

27

Prediction of the heat release rate of wood  

SciTech Connect (OSTI)

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

Parker, W.J.

1988-01-01T23:59:59.000Z

28

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

SciTech Connect (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

29

Mold Heating and Cooling Pump Package Operator Interface Controls Upgrade  

SciTech Connect (OSTI)

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

30

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

SciTech Connect (OSTI)

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

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

2006-07-15T23:59:59.000Z

31

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

32

Cloud Properties and Radiative Heating Rates for TWP  

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

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

Comstock, Jennifer

33

Cloud Properties and Radiative Heating Rates for TWP  

SciTech Connect (OSTI)

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

Comstock, Jennifer

2013-11-07T23:59:59.000Z

34

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

35

Broadband Heating Rate Profile Project (BBHRP) - SGP ripbe370mcfarlane  

SciTech Connect (OSTI)

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

Riihimaki, Laura; Shippert, Timothy

2014-11-05T23:59:59.000Z

36

Broadband Heating Rate Profile Project (BBHRP) - SGP ripbe1mcfarlane  

SciTech Connect (OSTI)

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

Riihimaki, Laura; Shippert, Timothy

2014-11-05T23:59:59.000Z

37

Broadband Heating Rate Profile Project (BBHRP) - SGP ripbe1mcfarlane  

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

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

Riihimaki, Laura; Shippert, Timothy

38

Broadband Heating Rate Profile Project (BBHRP) - SGP ripbe370mcfarlane  

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

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

Riihimaki, Laura; Shippert, Timothy

39

TRANSIENT HEAT TRANSFER ANALYSIS FOR SRS RADIOACTIVE TANK OPERATION  

SciTech Connect (OSTI)

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

40

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

SciTech Connect (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

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

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

E-Print Network [OSTI]

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

Skogestad, Sigurd

42

Control system for, and a method of, heating an operator station of a work machine  

DOE Patents [OSTI]

There are situations in which an operator remains in an operator station of a work machine when an engine of the work machine is inactive. The present invention includes a control system for, and a method of, heating the operator station when the engine is inactive. A heating system of the work machine includes an electrically-powered coolant pump, a power source, and at least one piece of warmed machinery. An operator heat controller is moveable between a first and a second position, and is operable to connect the electrically-powered coolant pump to the power source when the engine is inactive and the operator heat controller is in the first position. Thus, by deactivating the engine and then moving the operator heat controller to the first position, the operator may supply electrical energy to the electrically-powered coolant pump, which is operably coupled to heat the operator station.

Baker, Thomas M.; Hoff, Brian D.; Akasam, Sivaprasad

2005-04-05T23:59:59.000Z

43

IEA Heat Pump Conference 2011, 16 -19 May 2011, Tokyo, Japan ENERGY EFFICIENT AIR TO AIR HEAT PUMP OPERATING WITH  

E-Print Network [OSTI]

00149 -1- 10th IEA Heat Pump Conference 2011, 16 - 19 May 2011, Tokyo, Japan ENERGY EFFICIENT AIR TO AIR HEAT PUMP OPERATING WITH R-1234yf Sorina Mortada, Ph.D. student, Center for Energy and Processes Abstract: Significant improvements in energy performance of air-to-air heat pumps are the major reason

Paris-Sud XI, Université de

44

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

E-Print Network [OSTI]

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

Haviland, David

45

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

SciTech Connect (OSTI)

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

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

1996-05-01T23:59:59.000Z

46

7-117 The claim of a heat pump designer regarding the COP of the heat pump is to be evaluated. Assumptions The heat pump operates steadily.  

E-Print Network [OSTI]

7-47 7-117 The claim of a heat pump designer regarding the COP of the heat pump is to be evaluated. Assumptions The heat pump operates steadily. HP Wnet,in QH QL TL TH Analysis The maximum heat pump coefficient of performance would occur if the heat pump were completely reversible, 5.7 K026K300 K300 COP maxHP, LH H TT

Bahrami, Majid

47

Effect of Heating Rate on Glass Foaming: Transition to Bulk Foam  

SciTech Connect (OSTI)

Foaming of glass is an undesirable side effect of glass fining. According to a recent experimental study, the gas-phase volume in the melt heated at a constant rate dramatically increased with an increased rate of heating. This observation indicates that an increased rate of heating (a natural consequence of the increased processing rate experienced as a result of transition to oxy-fuel firing) may exert a substantial influence on glass foaming in advanced glass-melting furnaces. This paper attributes this effect to the change of mode of foam formation in response to an increased rate of heating.

Hrma, Pavel R.

2009-02-15T23:59:59.000Z

48

A study of the volatile matter of coal as a function of the heating rate  

SciTech Connect (OSTI)

A study of the volatile matter yields as a function of the heating rate was conducted. A suite of 21 coal and coke samples varying in rank from anthracitic to lignitic and heating rates from 10{degrees}C/min to about 450{degrees}C/min were used in the study. Heating rates up to 60{degrees}C per minute, which are typically used in ASTM Test Method 5142 (instrumental Proximate Analysis), were achieved in a macro thermogravimetric analysis (TGA) system. Heating rates of 50-200{degrees}C/min were obtained in a micro TGA system. All measurements were made in a nitrogen atmosphere. The results of the study illustrate the dependence of the volatile matter yield on the heating rate. For most coals and cokes the optimum heating rate for determining volatile matter values that agree with those obtained by ASTM Method D 3175 appears to be in the 100-150{degrees}C range.

Yanes, E.; Wilhite, D.; Riley, J.M. Jr. [Western Kentucky Univ., Bowling Green, KY (United States)] [and others

1996-12-31T23:59:59.000Z

49

Degrees of freedom and optimal operation of simple heat pump cycles  

E-Print Network [OSTI]

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

Skogestad, Sigurd

50

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

E-Print Network [OSTI]

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

Marquez Gonzalez, Mayra

2009-05-15T23:59:59.000Z

51

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

E-Print Network [OSTI]

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

52

Improving Heating System Operations Using Water Re-Circulation  

E-Print Network [OSTI]

In order to solve the imbalance problem of a heating system, brought about by consumer demand and regulation, and save the electricity energy consumed by a circulation pump, a water mixing and pressure difference control heating system is proposed...

Li, F.; Han, J.

2006-01-01T23:59:59.000Z

53

Effect of Turbulence Fluctuations on Surface Heating Rate in Hypersonic Turbulent  

E-Print Network [OSTI]

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

Martín, Pino

54

High pressure low heat rate phosphoric acid fuel cell stack  

SciTech Connect (OSTI)

A high pressure phosphoric acid fuel cell stack assembly is described comprising: (a) a stack of fuel cells for producing electricity, the stack including cathode means, anode means, and heat exchange means; (b) means for delivering pressurized air to the cathode means; (c) means for delivering a hydrogen rich fuel gas to the anode means for electrochemically reacting with oxygen in the pressurized air to produce electricity and water; (d) first conduit means connected to the cathode means for exhausting a mixture of oxygen-depleted air and reaction water from the cathode means; (e) second conduit means connected to the first conduit means for delivering a water fog to the first conduit means for entrainment in the mixture of oxygen-depleted air and reaction water to form a two phase coolant having a gaseous air phase and an entrained water droplet phase; (f) means for circulating the coolant to the heat exchange means to cool the stack solely through vaporization of the water droplet phase in the heat exchange means whereby a mixed gas exhaust of air and water vapor is exhausted from the heat exchange means; and (g) means for heating the mixed gas exhaust and delivering the heated mixed gas exhaust at reformer reaction temperatures to an autothermal reformer in the stack assembly for autothermal reaction with a raw fuel to form the hydrogen rich fuel.

Wertheim, R.J.

1987-07-07T23:59:59.000Z

55

Numerical Study of Convective Heat Transfer in Flat Tube Heat Exchangers Operating in Self-Sustained Oscillatory Flow Regimes  

E-Print Network [OSTI]

Laminar, two-dimensional, constant-property numerical simulations of flat tube heat exchanger devices operating in flow regimes in which self-sustained oscillations occur were performed. The unsteady flow regimes were transition flow regimes...

Fullerton, Tracy

2012-02-14T23:59:59.000Z

56

Nano-engineering the boiling surface for optimal heat transfer rate and critical heat flux  

E-Print Network [OSTI]

The effects on pool boiling characteristics such as critical heat flux and the heat transfer coefficient of different surface characteristics such as surface wettability, roughness, morphology, and porosity are not well ...

Phillips, Bren Andrew

2011-01-01T23:59:59.000Z

57

Semilinear response for the heating rate of cold atoms in vibrating traps  

E-Print Network [OSTI]

OFFPRINT Semilinear response for the heating rate of cold atoms in vibrating traps A. Stotland, D;Europhysics Letters (EPL) has a new online home at www.epljournal.org Take a look for the latest journal news.epljournal.org doi: 10.1209/0295-5075/86/10004 Semilinear response for the heating rate of cold atoms in vibrating

Cohen, Doron

58

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

E-Print Network [OSTI]

Evidence for thermalization of surface-desorbed molecules at heating rates of 108 K/s C. R of aniline-d7 from a single-crystal surface 0001 of sapphire Al2O3 at a heating rate on the order of 108 K/s was studied using pulsed infrared laser radiation for desorption and resonance enhanced multiphoton ionization

Zare, Richard N.

59

Cloud properties and associated radiative heating rates in the tropical western Pacific  

E-Print Network [OSTI]

Cloud properties and associated radiative heating rates in the tropical western Pacific James H set of atmospheric remote sensing instruments at sites around the world, including three radiative fluxes and heating rates. Maxima in cloud occurrence are found in the boundary layer and the upper

60

ELECTRIC CO-HEATING: A METHOD FOR EVALUATING SEASONAL HEATING EFFICIENCIES AND HEAT LOSS RATES IN DWELLINGS  

E-Print Network [OSTI]

and heating efficiency, inexpensive and practical diagnosti.c techniques are needed, such as pressuriza- tion, infrared

Modera, M.P.

2012-01-01T23:59:59.000Z

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.


61

Heat-and-Run: Leveraging SMT and CMP to Manage Power Density Through the Operating System  

E-Print Network [OSTI]

Heat-and-Run: Leveraging SMT and CMP to Manage Power Density Through the Operating System Mohamed and thermal ability of packages to dissipate heat. Power den- sity is characterized by localized chip hot Performance, Reliability Keywords Power density, heat, CMP, SMT, migration 1 INTRODUCTION Power

Vijaykumar, T. N.

62

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

E-Print Network [OSTI]

super-heating, pressure, liquid level or valve set-point. Unlike open systems the initial charge applications have also merged together to give a system able to operate in both heating and cooling mode indicates that 33% of the gained heat is addet as electricity. In industrial processes, especially

Skogestad, Sigurd

63

Convergence Rates with Inexact Non-expansive Operators  

E-Print Network [OSTI]

The power of convex relaxation: near-optimal matrix completion. IEEE Trans. Inform. ... On the numerical solution of heat conduction problems in two and three

2014-06-11T23:59:59.000Z

64

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

65

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

66

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

67

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

SciTech Connect (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

68

Project Profile: High Operating Temperature Liquid Metal Heat...  

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

A freezing point below 100C Stable at temperatures greater than 800C Low corrosion of stainless steel and high-nickel content alloys A heat capacity greater than 2...

69

Effects of operating conditions on a heat transfer fluid aerosol  

E-Print Network [OSTI]

of heat transfer fluid aerosols from process leaks. To simulate industrial leaks, aerosol formation from a plain orifice into ambient air is studied by measuring liquid drop sizes and size distributions at various distances from an orifice. Measurements...

Sukmarg, Passaporn

2000-01-01T23:59:59.000Z

70

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

SciTech Connect (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

71

JP2.3 CLOUD RADIATIVE HEATING RATE FORCING FROM PROFILES OF RETRIEVED ARCTIC CLOUD MICROPHYSICS  

E-Print Network [OSTI]

JP2.3 CLOUD RADIATIVE HEATING RATE FORCING FROM PROFILES OF RETRIEVED ARCTIC CLOUD MICROPHYSICS surface. In 1997-1998, a large multi-agency effort made the Surface Heat Budget of the Arctic (SHEBA with the ice pack in the Beaufort and Chukchi Seas for one year. Surface-based remote sensors generated

Shupe, Matthew

72

High Operating Temperature Liquid Metal Heat Transfer Fluids...  

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

plant. A successful candidate fluid would allow for the reduction of the levelized cost of energy by increasing the operating temperature for the CSP plant power cycle, which...

73

Preliminary Retro-Commissioning Study on Optimal Operation for the Heat Source System of a District Heating Cooling Plant  

E-Print Network [OSTI]

Heating Water Suuply Chilled Water Return Heating Water Return To User New System ESL-IC-08-10-57 Proceedings of the Eighth International Conference for Enhanced Building Operations, Berlin, Germany, October 20-22, 2008 2 attract attention due..., R6 450 1, 1 ESL-IC-08-10-57 Proceedings of the Eighth International Conference for Enhanced Building Operations, Berlin, Germany, October 20-22, 2008 3 (one office building and one building with hotel rooms and leisure facilities) since November...

Shingu, H.; Yoshida, H.; Wang, F.; Ono, E.

74

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

SciTech Connect (OSTI)

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

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

1988-02-01T23:59:59.000Z

75

Property:Heat Recovery Rating | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy ResourcesLoadingPenobscot County, Maine:PlugNumberOfArraProjectTypeTopic2GrossGen JumpRating Jump to:

76

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

SciTech Connect (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

77

Operator renewal theory and mixing rates for dynamical systems with in nite measure  

E-Print Network [OSTI]

Operator renewal theory and mixing rates for dynamical systems with in#12;nite measure Ian of operator renewal sequences in the context of in#12;nite ergodic theory. For large classes of dynamical for mixing rates. Sarig [37] introduced a powerful new technique, operator renewal theory, to obtain precise

78

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

SciTech Connect (OSTI)

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

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

2014-03-01T23:59:59.000Z

79

On the maximum pressure rise rate in boosted HCCI operation  

E-Print Network [OSTI]

This paper explores the combined effects of boosting, intake air temperature, trapped residual gas fraction, and dilution on the Maximum Pressure Rise Rate (MPRR) in a boosted single cylinder gasoline HCCI engine with ...

Wildman, Craig B.

80

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

SciTech Connect (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

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

California Federal Facilities: Rate-Responsive Buidling Operating for Deeper Cost and Energy Savings  

Broader source: Energy.gov [DOE]

Fact sheet from the Federal Energy Management Program (FEMP) describes rate-responsive building operations for cost and energy savings in California federal facilities.

82

Inverse bremsstrahlung heating rate in xenon clusters in the eikonal approximation  

SciTech Connect (OSTI)

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

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

2013-03-15T23:59:59.000Z

83

Proceedings: 2003 EPRI Heat Rate Improvement Conference: January 28-30, 2003, Birmingham, AL  

SciTech Connect (OSTI)

Every utility strives both to become a low-cost electricity producer and to meet the emission standards set by the Clean Air Act Amendment. In the early round of cost and emission reduction, most utilities opted to blend or switch to lower-cost fuels such as Powder River Basin coal and natural gas. Over the years, EPRI, industry vendors, and the utilities themselves have learned not only to reduce the difficulties encountered with fuel blending and switching, but also to improve plant heat rate with various cost-effective solutions. The 2003 Heat Rate Improvement Conference provided an opportunity for the industry to share its knowledge and experience.

None

2003-04-01T23:59:59.000Z

84

Methodology for Calculating Cooling and Heating Energy-Imput-Ratio (EIR) From the Rated Seasonal Performance Efficiency (SEER or HSPF)  

E-Print Network [OSTI]

This report provides the recommendations to calculate cooling and heating energy-input-ratio (EIR) for DOE-2 simulations excluding indoor fan energy, from the rated cooling and heating seasonal performance efficiency (i.e., SEER or HSPF) that does...

Kim, H.; Baltazar, J. C.; Haberl, J. S.

2013-01-01T23:59:59.000Z

85

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

E-Print Network [OSTI]

Operator renewal theory and mixing rates for dynamical systems with infinite measure Ian Melbourne renewal sequences in the context of infinite ergodic theory. For large classes of dynamical systems technique, operator renewal theory, to obtain precise asymptotics and hence sharp mixing rates

86

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 Jaschke, 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

87

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

SciTech Connect (OSTI)

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

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

1995-01-01T23:59:59.000Z

88

RIS-M-2185 CALCULATION OF HEAT RATING AND BURN-UP FOR TEST FUEL PINS  

E-Print Network [OSTI]

RIS-M-2185 CALCULATION OF HEAT RATING AND BURN-UP FOR TEST FUEL PINS IRRADIATED IN DR3 C. Bagger of fuel pins irradiated in HP1 rigs. The calculations are carried out rather detailed, especially of the data. INIS Descriptors . BURN-UP, CALORIMETRY, COMPUTER CALCULATIONS, DR-3, FISSION, FUEL ASSEMBLIES

89

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

SciTech Connect (OSTI)

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

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

2014-07-07T23:59:59.000Z

90

Influence of viscous friction heating on the efficiency of columns operated under very high pressures  

SciTech Connect (OSTI)

When columns packed with very fine particles are operated at high mobile phase velocities, the friction of the mobile phase percolating through the column bed generates heat. This heat dissipates along and across the column and axial and radial temperature gradients appear. The wall region of the column tends to be cooler than its center, and due to the influence of temperature on the mobile phase viscosity and on the equilibrium constant of analytes, the band velocity is not constant across the column. This radial heterogeneity of the temperature distribution across the column contributes to band broadening. This phenomenon was investigated assuming a cylindrically symmetrical column and using the general dispersion theory of Aris, which relates the height equivalent to the theoretical plate (HETP) contribution due to a radial heterogeneity of the column to the radial distribution of the linear velocities of a compound peak and to the radial distribution of its apparent dispersion coefficients in the column bed. The former is known from the temperature gradient across the column, the temperature dependencies of the mobile phase viscosity, and the retention factor of the compound. The latter is derived from the known expression of the transverse reduced HETP equation for the column. The values of the HETP calculated with the Aris model and a classical HETP equation were compared to those measured on a 2.1 x 50 mm Acquity BEH-C{sub 18} column, run at flow rates of 0.6, 0.95, 1.30, and 1.65 mL/min, with pure acetonitrile as the mobile phase and naphtho[2,3-a]pyrene as the retained compound. These two sets of data are in generally good agreement, although the experimental values of the HETP tend to increase faster with increasing mobile phase velocity than the calculated values.

Gritti, Fabrice [University of Tennessee, Knoxville (UTK); Guiochon, Georges A [ORNL

2009-01-01T23:59:59.000Z

91

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

E-Print Network [OSTI]

. Castings are then normalized and tempered in separate fluid bath furnaces with the entire operation being completed within a few hours of pouring. Fluid baths are also used for cooling of spent sand and for quenching of castings. Trial applications...

Kemp, W. E.

1981-01-01T23:59:59.000Z

92

Fluid Bed Waste Heat Boiler Operating Experience in Dirty Gas Streams  

E-Print Network [OSTI]

on an aluminium melting furnace at the ALCOA Massena Integrated Aluminum Works in upstate New York. Waste heat from an aluminum melting furnace is captured for general plant use for the first time in this plant. It is accomplished with advanced fluid bed heat... recovery that typically can save energy equivalent to 40% of the furnace firing rate. Previous attempts to recovery energy conven tionally on this type of furnace were unsuccessful due to fouling. The resolution of this fouling problem by using...

Kreeger, A. H.

93

The new Kaiserstuhl coking plant: The heating system -- Design, construction and initial operating experience  

SciTech Connect (OSTI)

At the end of 1992 the new coke plant Kaiserstuhl in Dortmund/Germany with presently the largest coke ovens world-wide started its production operation in close linkage to the Krupp-Hoesch Metallurgical Works after about 35 months construction time. This plant incorporating comprehensive equipment geared to improve environmental protection is also considered as the most modern coke plant of the world. The heating-system and first results of operation will be presented.

Strunk, J.

1996-12-31T23:59:59.000Z

94

Low-coke rate operation under high PCI at Kobe No. 3 BF  

SciTech Connect (OSTI)

Kobe No. 3 blast furnace (BF) suffered tremendous damage when the Great Hanshin-Awaji Earthquake rocked the area on January 17, 1995. However, working as quickly as possible to dig out of the burden and rehabilitate various facilities, the company managed to restart the No. 3 BF on April 2. After the restart, which went smoothly, production was shifted into the low coke rate operation which was being promoted before the disaster. In October, 1995, only seven months after the restart, the nation record of 296 kg/t low coke rate could be achieved. Subsequently, in January, 1996, coke rate reached 290 kg/t and the low coke rate operation was renewed. Since that time the same level of coke rate has been maintained. The paper discusses how low coke rate operation was achieved.

Matsuo, Tadasu; Kanazuka, Yasuo; Hoshino, Koichi; Yoshida, Yasuo; Kitayama, Syuji; Ishiwaki, Shiro [Kobe Steel Ltd. (Japan). Kobe Works

1997-12-31T23:59:59.000Z

95

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

96

Establishing low-power operating limits for liquid metal heat pipes  

SciTech Connect (OSTI)

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

97

Establishing low-power operating limits for liquid metal heat pipes  

SciTech Connect (OSTI)

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

98

Automatic coke oven heating control system at Burns Harbor for normal and repair operation  

SciTech Connect (OSTI)

An automatic heating control system for coke oven batteries was developed in 1985 for the Burns Harbor No. 1 battery and reported in the 1989 Ironmaking Conference Proceedings. The original system was designed to maintain a target coke temperature at a given production level under normal operating conditions. Since 1989, enhancements have been made to this control system so that it can also control the battery heating when the battery is under repair. The new control system has improved heating control capability because it adjusts the heat input to the battery in response to anticipated changes in the production schedule. During a recent repair of this 82 oven battery, the pushing schedule changed from 102 ovens/day to 88 ovens/day, then back to 102 ovens/day, then to 107 ovens/day. During this repair, the control system was able to maintain the coke temperature average standard deviation at 44 F, with a maximum 75 F.

Battle, E.T.; Chen, K.L. [Bethlehem Steel Corp., Burns Harbor, IN (United States); [Bethlehem Steel Corp., PA (United States)

1997-12-31T23:59:59.000Z

99

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

SciTech Connect (OSTI)

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

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

2014-02-07T23:59:59.000Z

100

PUBLISHED VERSION Ion cyclotron resonance frequency heating in JET during initial operations with the ITER-like wall  

E-Print Network [OSTI]

PUBLISHED VERSION Ion cyclotron resonance frequency heating in JET during initial operations.1063/1.4884354 #12;Ion cyclotron resonance frequency heating in JET during initial operations with the ITER-mode regime in Alcator C-Moda) Phys. Plasmas 20, 055904 (2013); 10.1063/1.4803914 Upgrade of the infrared

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

Operational results for high pulverized coal injection rate at Kimitsu No. 3 blast furnace  

SciTech Connect (OSTI)

In order to further develop the technology for high-rate pulverized coal injection (PCI), namely over 200 kg/t-pig, Nippon Steel performed a high injection rate test at the Kimitsu No. 3 blast furnace in November, 1993. The paper describes PCI equipment; the operational design of the test, including blast conditions, reducibility of sinter, coke strength and burden distribution; and test results. These results include a discussion of the transition of operation, burden distribution control, replacement ratio of coke, permeability at upper and lower parts of the furnace, reducibility at lower part of the furnace, accumulation of fines in the deadman, and generation and accumulation of unburnt char. Stable operation was achieved at a PCI rate of 190 kg/t-pig. With injection rates between 200--300 kg/t-pig, the problem becomes how to improve the reduction-meltdown behavior in the lower part of the furnace.

Ueno, Hiromitsu; Matsunaga, Shin`ichi; Kakuichi, Kazumoto; Amano, Shigeru; Yamaguchi, Kazuyoshi

1995-12-01T23:59:59.000Z

102

Note: Operation of gamma-ray microcalorimeters at elevated count rates using filters with constraints  

SciTech Connect (OSTI)

Microcalorimeter sensors operated near 0.1 K can measure the energy of individual x- and gamma-ray photons with significantly more precision than conventional semiconductor technologies. Both microcalorimeter arrays and higher per pixel count rates are desirable to increase the total throughput of spectrometers based on these devices. The millisecond recovery time of gamma-ray microcalorimeters and the resulting pulse pileup are significant obstacles to high per pixel count rates. Here, we demonstrate operation of a microcalorimeter detector at elevated count rates by use of convolution filters designed to be orthogonal to the exponential tail of a preceding pulse. These filters allow operation at 50% higher count rates than conventional filters while largely preserving sensor energy resolution.

Alpert, B. K.; Horansky, R. D.; Bennett, D. A.; Doriese, W. B.; Fowler, J. W.; Ullom, J. N. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); Hoover, A. S.; Rabin, M. W. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2013-05-15T23:59:59.000Z

103

Ion cyclotron resonance frequency heating in JET during initial operations with the ITER-like wall  

SciTech Connect (OSTI)

In 2011/12, JET started operation with its new ITER-Like Wall (ILW) made of a tungsten (W) divertor and a beryllium (Be) main chamber wall. The impact of the new wall materials on the JET Ion Cyclotron Resonance Frequency (ICRF) operation is assessed and some important properties of JET plasmas heated with ICRF are highlighted. A???20% reduction of the antenna coupling resistance is observed with the ILW as compared with the JET carbon (JET-C) wall. Heat-fluxes on the protecting limiters close the antennas, quantified using Infra-Red thermography (maximum 4.5?MW/m{sup 2} in current drive phasing), are within the wall power load handling capabilities. A simple RF sheath rectification model using the antenna near-fields calculated with the TOPICA code can reproduce the heat-flux pattern around the antennas. ICRF heating results in larger tungsten and nickel (Ni) contents in the plasma and in a larger core radiation when compared to Neutral Beam Injection (NBI) heating. The location of the tungsten ICRF specific source could not be identified but some experimental observations indicate that main-chamber W components could be an important impurity source: for example, the divertor W influx deduced from spectroscopy is comparable when using RF or NBI at same power and comparable divertor conditions, and Be evaporation in the main chamber results in a strong reduction of the impurity level. In L-mode plasmas, the ICRF specific high-Z impurity content decreased when operating at higher plasma density and when increasing the hydrogen concentration from 5% to 15%. Despite the higher plasma bulk radiation, ICRF exhibited overall good plasma heating performance; the power is typically deposited at the plasma centre while the radiation is mainly from the outer part of the plasma bulk. Application of ICRF heating in H-mode plasmas has started, and the beneficial effect of ICRF central electron heating to prevent W accumulation in the plasma core has been observed.

Jacquet, P., E-mail: philippe.jacquet@ccfe.ac.uk; Monakhov, I.; Arnoux, G.; Brix, M.; Graham, M.; Meigs, A.; Sirinelli, A. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Bobkov, V.; Devaux, S.; Drewelow, P.; Ptterich, T. [Max-Planck-Institut fr Plasmaphysik, EURATOM-Assoziation, Garching (Germany); Colas, L. [CEA, IRFM, F-13108 Saint-Paul-Lez-Durance (France); Czarnecka, A. [Association Euratom-IPPLM, Hery 23, 01-497 Warsaw (Poland); Lerche, E.; Van-Eester, D. [Association EURATOM-Belgian State, ERM-KMS, Brussels (Belgium); Mayoral, M.-L. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); EFDA Close Support Unit, Garching (Germany); Brezinsek, S. [IEK-4, Forschungszentrum Jlich, Association EURATOM-FZJ, Jlich (Germany); Campergue, A.-L. [Ecole Nationale des Ponts et Chausses, F77455 Marne-la-Valle (France); Klepper, C. C. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6169 (United States); Milanesio, D. [Politecnico di Torino, Department of Electronics, Torino (Italy); and others

2014-06-15T23:59:59.000Z

104

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

E-Print Network [OSTI]

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

Saravanan, R.; Murugavel, V.

2010-01-01T23:59:59.000Z

105

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

SciTech Connect (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

106

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

107

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

SciTech Connect (OSTI)

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

Riihimaki, Laura; Shippert, Timothy

2014-11-05T23:59:59.000Z

108

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

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

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

Riihimaki, Laura; Shippert, Timothy

109

Operation and Thermal Modeling of the ISIS H Source from 50 to 2 Hz Repetition Rates  

E-Print Network [OSTI]

CERNs Linac4 accelerator H? ion source, currently under construction, will operate at a 2 Hz repetition rate, with pulse length of 0.5 ms and a beam current of 80 mA. Its reliability must exceed 99 % with a mandatory 3 month uninterrupted operation period. A Penning ion source is successfully operated at ISIS; at 50 Hz repetition rate it reliably provides 55 mA H? pulses of 0.25 ms duration over 1 month. The discharge plasma ignition is very sensitive to the temperatures of the discharge region, especially of its cathode. The investigation by modeling and measurement of operation parameters suitable for arc ignition and H? production at 2 Hz is of paramount importance and must be understood prior to the implementation of discharge ion sources in the Linac4 accelerator. In its original configuration, the ISIS H? source delivers beam only if the repetition rate is above 12.5 Hz, this paper describes the implementation of a temperature control of the discharge region aiming at lower repetition rate op...

Pereira, H; Lettry, J

2013-01-01T23:59:59.000Z

110

EIS-0302: Transfer of the Heat Source/Radioisotope Thermoelectric Generator Assembly and Test Operations From the Mound Site  

Broader source: Energy.gov [DOE]

This EIS analyzes DOE's proposed transfer of the Heat Source/Radioisotope Thermoelectric Generator (HS/RTG) operations at the Mound Site near Miamisburg, Ohio, to an alternative DOE site.

111

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

SciTech Connect (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

112

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

SciTech Connect (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

113

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

SciTech Connect (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

114

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 walls. Air Products tasked our team to design an insert to place in the tubes of the WHB to increase flow velocity, thereby reducing fouling of the WHB. Objectives Air Products wishes that our team

Demirel, Melik C.

115

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

SciTech Connect (OSTI)

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

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

1995-05-01T23:59:59.000Z

116

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

117

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

E-Print Network [OSTI]

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

Womeldorf, Carole

118

Steady state heat transfer experimental studies of LHC superconducting cables operating in cryogenic environment of superfluid helium  

E-Print Network [OSTI]

The heat management is a basic and fundamental aspect of the superconducting magnets used in the CERN Large Hadron Collider. Indeed, the coil temperature must be kept below the critical value, despite the heat which can be generated or deposited in the magnet during the normal operations. Therefore, this thesis work aims at determining the heating power which can be extracted from the superconducting cables of the LHC, specially through their electrical insulation which represents the main thermal barrier. An experimental measurement campaign in superfluid helium bath was performed on several samples reproducting the main LHC magnets. The heating power was generated in the sample by Joule heating and the temperature increase was measured by means of Cernox bare chip and thermocouples. An innovative instrumentation technique which also includes the in-situ calibration of the thermocouples was developed. A thorough uncertainty analysis on the overall measurement chain concluded the experimental setup. The prese...

Santandrea, Dario; Tuccillo, Raffaele; Granieri, Pier Paolo.

119

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

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

release * Metal engine experiments have shown that RCCI combustion using in-cylinder fuel blending allows low NOx and soot operation over a wide range of operating conditions -...

120

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

E-Print Network [OSTI]

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

Oak Ridge National Laboratory

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.


121

PUBLISHED VERSION ICRF heating in JET during initial operations with the ITER-like wall  

E-Print Network [OSTI]

. Heat-fluxes on the protecting limiters close the antennas quantified using Infra-Red (IR) thermography

122

A Simple Control Scheme for Near-optimal Operation of Parallel Heat Exchanger Systems  

E-Print Network [OSTI]

. In the chemical and process industries, large amounts of energy can be saved by using heat recovery in heat exchanger networks, which transfer energy in form of heat Corresponding author: email: skoge@ntnu.no, phone exchanger networks for saving energy and costs has led to a large body of research, and most

Skogestad, Sigurd

123

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

SciTech Connect (OSTI)

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

Hufnagel, Todd C.

2014-06-09T23:59:59.000Z

124

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

DOE Patents [OSTI]

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

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

2004-09-21T23:59:59.000Z

125

7-84E The claim of an inventor about the operation of a heat engine is to be evaluated. Assumptions The heat engine operates steadily.  

E-Print Network [OSTI]

efficiency would be 0.45 R1000 R550 11maxth, H L T T K 550 R 1000 R HE HQ 15,000 Btu/h 5 hp When the first law is applied to the engine above, Btu/h720,27Btu/h000,15 hp1 Btu/h2544.5 )hp5(net ¸¸ ¹ · ¨¨ © § LH QWQ The actual thermal efficiency of the proposed heat engine is then 459.0 hp1 Btu/h2544.5 Btu/h27

Bahrami, Majid

126

7-122 A solar pond power plant operates by absorbing heat from the hot region near the bottom, and rejecting waste heat to the cold region near the top. The maximum thermal efficiency that the power plant  

E-Print Network [OSTI]

calculated above. 7-123 A Carnot heat engine cycle is executed in a closed system with a fixed mass of steam can have is to be determined. Analysis The highest thermal efficiency a heat engine operating between transfer. Therefore, the maximum efficiency of the actual heat engine will be lower than the value

Bahrami, Majid

127

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  

SciTech Connect (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] [ORNL; Munk, Jeffrey D [ORNL] [ORNL; Baxter, Van D [ORNL] [ORNL; Gehl, Anthony C [ORNL] [ORNL

2012-01-01T23:59:59.000Z

128

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

SciTech Connect (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

129

Measurement of limiter heating due to fusion product losses during high fusion power deuterium-tritium operation of TFTR  

SciTech Connect (OSTI)

Preliminary analysis has been completed on measurements of limiter heating during high fusion power deuterium-tritium (D-T) operation of TFTR, in an attempt to identify heating from alpha particle losses. Recent operation of TFTR with a 50-50 mix of D-T has resulted in fusion power output ({approx} 6.2 MW) orders of magnitude above what was previously achieved on TFTR. A significantly larger absolute number of particles and energy from fusion products compared to D-D operation is expected to be lost to the limiters. Measurements were made in the vicinity of the midplane ({plus_minus} 30{degree}) with thermocouples mounted on the tiles of an outboard limiter. Comparisons were made -between discharges which were similar except for the mix of deuterium and tritium beam sources. Power and energy estimates of predicted alpha losses were as high as 0.13 MW and 64 kJ. Depending on what portion of the limiters absorbed this energy, temperature rises of up to 42 {degrees}C could be expected, corresponding to a heat load of 0.69 MJ/m{sup 2} over a 0.5 sec period, or a power load of 1.4 MW/m{sup 2}. There was a measurable increase in the limiter tile temperature as the fusion power yield increased with a more reactive mixture of D and T at constant beam power during high power D-T operation. Analysis of the data is being conducted to see if the alpha heating component can be extracted. Measured temperature increases were no greater than 1 {degree}C, indicating that there was probably neither an unexpectedly large fraction of lost particles nor unexpected localization of the losses. Limits on the stochastic ripple loss contribution from alphas can be deduced.

Janos, A.; Owens, D.K.; Darrow, D.; Redi, M.; Zarnstorff, M.; Zweben, S.

1995-03-01T23:59:59.000Z

130

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

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensional Subject:Ground Source Heat2 December 2006 DOEthe

131

Comparative Performance Analysis of IADR Operating in Natural Gas-Fired and Waste-Heat CHP Modes  

SciTech Connect (OSTI)

Fuel utilization can be dramatically improved through effective recycle of 'waste' heat produced as a by-product of on-site or near-site power generation technologies. Development of modular compact cooling, heating, and power (CHP) systems for end-use applications in commercial and institutional buildings is a key part of the Department of Energy's (DOE) energy policy. To effectively use the thermal energy from a wide variety of sources which is normally discarded to the ambient, many components such as heat exchangers, boilers, absorption chillers, and desiccant dehumidification systems must be further developed. Recently a compact, cost-effective, and energy-efficient integrated active-desiccant vapor-compression hybrid rooftop (IADR) unit has been introduced in the market. It combines the advantages of an advanced direct-expansion cooling system with the dehumidification capability of an active desiccant wheel. The aim of this study is to compare the efficiency of the IADR operation in baseline mode, when desiccant wheel regeneration is driven by a natural gas burner, and in CHP mode, when the waste heat recovered from microturbine exhaust gas is used for desiccant regeneration. Comparative analysis shows an excellent potential for more efficient use of the desiccant dehumidification as part of a CHP system and the importance of proper sizing of the CHP components. The most crucial factor in exploiting the efficiency of this application is the maximum use of thermal energy recovered for heating of regeneration air.

Petrov, Andrei Y [ORNL; Sand, James R [ORNL; Zaltash, Abdolreza [ORNL

2006-01-01T23:59:59.000Z

132

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

E-Print Network [OSTI]

. .......................................... 53 Figure 21 Rate simulation for the same case as Fig. 20. ............................................... 54 Figure 22 Buildup charts for the same case as in Fig. 10. ............................................. 54 Figure 23 Pareto chart... ................................................................................ 10 CHAPTER III MODEL DEVELOPMENT .................................................................... 12 Introduction .................................................................................................................. 12 Steady...

Hashmi, Gibran Mushtaq

2014-07-08T23:59:59.000Z

133

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

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe U.S. Improving Fan System PerformanceIn situIn

134

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

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensional Subject:Ground Source Heat2 December 2006 DOEthe Public15/2014

135

Operational limit of closed loop pulsating heat pipes Honghai Yang a,*, S. Khandekar b  

E-Print Network [OSTI]

a College of Environmental Science and Engineering, Donghua University, Shanghai 200051, PR China b of a total of 40 copper tubes with 1 mm and 2 mm inner diameter, respectively. R123 was employed important ones. In both cases the limit will manifest itself by an unacceptable over- heating

Khandekar, Sameer

136

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 (OSTI)

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

137

Improving central heating plant performance at the defense construction supply center (DCSC): Advanced operation and maintenance methods. Final report  

SciTech Connect (OSTI)

A 1987 air pollution emissions test done by the U.S. Army Environmental Hygiene Agency (USAEHA) identified several problems with the central heating plant (CHP) at the Defense Construction Supply Center (DCSC), Columbus, OH. Though DCSC repaired the specified problems, improved coal specifications, and tried to reduce air infiltration, CHP performance remained at unacceptable levels. Consequently, DCSC contracted the U.S. Army Construction Engineering Research Laboratories (USACERL) to apply advanced operation and maintenance procedures to improve its combustion system. This study employed a system-wide approach to evaluate the CHP 5 fuel storage, combustion, heat distribution, and the control of air emissions. Many short-term improvements to the CHP were identified and tested. Subsequent combustion and air emissions tests revealed that the recommended improvements successfully increased CHP efficiency. Long-term improvements were also recommended to help maintain the short-term improvements.

Savoie, M.J.; Standerfer, J.; Schmidt, C.M.; Gostich, J.; Mignacca, J.

1994-11-01T23:59:59.000Z

138

Understanding the operation and use of high temperature electrochemical corrosion rate probes  

SciTech Connect (OSTI)

Electrochemical corrosion rate probes were constructed and tested along with mass loss coupons in a N2/O2/CO2 plus water vapor environment. Temperatures ranged from 450 to 600 C. Corrosion rates for ash-covered mild steel, 304L SS, and 316L SS probes using electrochemical techniques were a function of time, temperature, and process environment. Correlation between electrochemical and mass loss corrosion rates was good.

Covino, Bernard S., Jr.; Bullard, Sophie J.; Cramer, Stephen D.; Holcomb, Gordon R.; Ziomek-Moroz, M.; Cayard, Michael S. (InterCorr International Inc.); Eden, David A. (InterCorr International Inc.)

2004-01-01T23:59:59.000Z

139

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

SciTech Connect (OSTI)

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

George A. Young; Nathan Lewis

2003-04-05T23:59:59.000Z

140

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

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

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

SciTech Connect (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, Ned S. (Cupertino, CA); Riley, David R. (West Newton, PA); Murray, Christopher S. (Bethel Park, PA); Geller, Clint B. (Pittsburgh, PA)

2000-01-01T23:59:59.000Z

142

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

SciTech Connect (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

143

ICRF heating at JET: From operations with a metallic wall to the long term perspective of a DT campaign  

SciTech Connect (OSTI)

The first series of experiments with the ITER-like wall (ILW) will start mid-2011 with D plasmas and will continue through 2012-13 with H, {sup 4}He and D plasmas, and up to 2014-15, when a DT campaign is proposed. In this paper, the previous experience at JET is reviewed to set the scene for the future challenges of ICRF operation including change in the ICRF coupling, W impurity production and evaluation of localized power loads due the RF sheaths. development in a Beryllium/Tungsten environment of ICRF heating schemes for the non activated and the DT phases of ITER.

Mayoral, M.-L.; Graham, M.; Jacquet, Ph.; Monakhov, I.; Riccardo, V. [Euratom/CCFE Fusion Association, Culham Science Centre, OX14 3DB (United Kingdom); Colas, L. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Eriksson, L.-G. [European Commission, Brussels, B-1049 (Belgium); Lerche, E.; Van Eester, D. [LPP-ERM/KMS, Association Euratom-'Belgian State' (Belgium)

2011-12-23T23:59:59.000Z

144

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...

Banerjee, Sibashis Sanatkumar

2012-06-07T23:59:59.000Z

145

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 Temperature Radiant Heating Systems Milorad Boji1*, Dragan Cvetkovi1 , Jasmina Skerli1 , Danijela Nikoli1, wall heating, floor heating, ceiling heating, EnergyPlus SUMMARY Low temperature heating panel systems

Paris-Sud XI, Université de

146

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 the heating mode. Both air-source and ground water source absorption heat pumps are considered, as well as air for estimating the heating and cooling seasonal performance and cost of operation of residential water chillers

Oak Ridge National Laboratory

147

Fuel-disruption experiments under high-ramp-rate heating conditions. [LMFBR  

SciTech Connect (OSTI)

This topical report presents the preliminary results and analysis of the High Ramp Rate fuel-disruption experiment series. These experiments were performed in the Annular Core Research Reactor at Sandia National Laboratories to investigate the timing and mode of fuel disruption during the prompt-burst phase of a loss-of-flow accident. High-speed cinematography was used to observe the timing and mode of the fuel disruption in a stack of five fuel pellets. Of the four experiments discussed, one used fresh mixed-oxide fuel, and three used irradiated mixed-oxide fuel. Analysis of the experiments indicates that in all cases, the observed disruption occurred well before fuel-vapor pressure was high enough to cause the disruption. The disruption appeared as a rapid spray-like expansion and occurred near the onset of fuel melting in the irradiated-fuel experiments and near the time of complete fuel melting in the fresh-fuel experiment. This early occurrence of fuel disruption is significant because it can potentially lower the work-energy release resulting from a prompt-burst disassembly accident.

Wright, S.A.; Worledge, D.H.; Cano, G.L.; Mast, P.K.; Briscoe, F.

1983-10-01T23:59:59.000Z

148

What is Wind Chill Temperature? It is the temperature it "feels like" outside and is based on the rate of heat loss  

E-Print Network [OSTI]

What is Wind Chill Temperature? It is the temperature it "feels like" outside and is based on the rate of heat loss from exposed skin caused by the effects of wind and cold. As the wind increases, the body is cooled at a faster rate causing the skin temperature to drop. Wind Chill does not impact

149

Fact #659: January 24, 2011 Fuel Economy Ratings for Vehicles Operating on  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat PumpRecord ofESPCofConstructionofFY 20112: July 19, 2010Energy 5:Fuel

150

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

151

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

SciTech Connect (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

152

Commissioning Process and Operational Improvement in the District Heating and Cooling-APCBC  

E-Print Network [OSTI]

-09-25 Proceedings of the 14th International Conference for Enhanced Building Operations, Beijing, China, September 14-17, 2014 18 Energy simulation In case of the variable cooling water flow system, the cooling water outlet temperature should be a parameter...,000 5,000 6,000 7,000 8,000 9,000 10,000 11,000 12,000 13,000 2012/10/072012/10/28 2012/11/18 2012/12/09 2012/12/30 2/24 ? 3/2 C o n su m ed e le ct ri ci ty p er h ea t u n it [ k W h /G J ] Variable water flow control Cooling tower fun Chilled...

Takase,T.; Takada,O; Shima,K.; Moriya, M.; Shimoda,Y.

2014-01-01T23:59:59.000Z

153

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

E-Print Network [OSTI]

. The lower the energy rating (KW/Ton or KW/HP or KW/BTU) the more efficient the equipment and the less demand draw on the electric power plants, thereby reducing the need to build new power plants. To encourage DSM, utilities give rebates for high...: Bob Allwein, Oklahoma Natural Gas Company. Dick Landry, Gulf States Utility. Curtis Williford, Entex Gas Company. Bret McCants, Central Power and Light Company. Frank Tanner, Southern Union. Patric Coon, West Texas utilities. ESL-IE-93...

Phillips, J. N.

154

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

E-Print Network [OSTI]

as a heat source/sink for heat pumps. Using the soil rather than the ambient air as the heat source in 1 heating and the heat sink in cooling offers potential thermodynamic advantages since the earth is normally at a more favorable temperature for heat...-coupled heat exchangers have proceeded in two different directions: (1) numerical solutions of the heat diffusion equation in the soil and the ground-coil [Mei and Fischer, 1984] and (2) modified analytical solutions [Al- Juwayhel, 1981; Bose et al., 1985...

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

1994-01-01T23:59:59.000Z

155

Heat storage with CREDA  

SciTech Connect (OSTI)

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

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

1987-01-01T23:59:59.000Z

156

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

SciTech Connect (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] [ORNL; Ally, Moonis Raza [ORNL] [ORNL; Baxter, Van D [ORNL] [ORNL

2012-01-01T23:59:59.000Z

157

Water and Space Heating Heat Pumps  

E-Print Network [OSTI]

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

Kessler, A. F.

1985-01-01T23:59:59.000Z

158

ANEMOS: A computer code to estimate air concentrations and ground deposition rates for atmospheric nuclides emitted from multiple operating sources  

SciTech Connect (OSTI)

This code estimates concentrations in air and ground deposition rates for Atmospheric Nuclides Emitted from Multiple Operating Sources. ANEMOS is one component of an integrated Computerized Radiological Risk Investigation System (CRRIS) developed for the US Environmental Protection Agency (EPA) for use in performing radiological assessments and in developing radiation standards. The concentrations and deposition rates calculated by ANEMOS are used in subsequent portions of the CRRIS for estimating doses and risks to man. The calculations made in ANEMOS are based on the use of a straight-line Gaussian plume atmospheric dispersion model with both dry and wet deposition parameter options. The code will accommodate a ground-level or elevated point and area source or windblown source. Adjustments may be made during the calculations for surface roughness, building wake effects, terrain height, wind speed at the height of release, the variation in plume rise as a function of downwind distance, and the in-growth and decay of daughter products in the plume as it travels downwind. ANEMOS can also accommodate multiple particle sizes and clearance classes, and it may be used to calculate the dose from a finite plume of gamma-ray-emitting radionuclides passing overhead. The output of this code is presented for 16 sectors of a circular grid. ANEMOS can calculate both the sector-average concentrations and deposition rates at a given set of downwind distances in each sector and the average of these quantities over an area within each sector bounded by two successive downwind distances. ANEMOS is designed to be used primarily for continuous, long-term radionuclide releases. This report describes the models used in the code, their computer implementation, the uncertainty associated with their use, and the use of ANEMOS in conjunction with other codes in the CRRIS. A listing of the code is included in Appendix C.

Miller, C.W.; Sjoreen, A.L.; Begovich, C.L.; Hermann, O.W.

1986-11-01T23:59:59.000Z

159

Simplified motional heating rate measurements of trapped ions R. J. Epstein,* S. Seidelin, D. Leibfried, J. H. Wesenberg, J. J. Bollinger, J. M. Amini, R. B. Blakestad, J. Britton,  

E-Print Network [OSTI]

Simplified motional heating rate measurements of trapped ions R. J. Epstein,* S. Seidelin, D. Leibfried, J. H. Wesenberg, J. J. Bollinger, J. M. Amini, R. B. Blakestad, J. Britton, J. P. Home, W. M have measured motional heating rates of trapped atomic ions, a factor that can influence multi

160

Recirculating Liquid Nitrogen System for Operation of Cryogenic Pumps  

E-Print Network [OSTI]

is provided by a LN2-cooled radiation shroud, which reduces the radiative heat load on the cryosail. Since Engineering, Mitchell.Walker@ae.gatech.edu #12;2 nitrogen shroud, the heat transfer calculated by Eqn. (1 operating temperature. This is seen notionally by equation 1: Eqn. (1) where Q is the rate of heat transfer

Walker, Mitchell

Note: This page contains sample records for the topic "operating heat rate" from the National Library of EnergyBeta (NLEBeta).
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161

Optimization of the design and mode of operation of a QD laser for reducing the heat-to-bitrate ratio  

SciTech Connect (OSTI)

Heat dissipation under the high-speed modulation of quantum dot edge-emitting lasers is considered. It is shown that, for a given laser diode, there is a bias current at which the heat-to-bitrate ratio is minimized. Moreover, there exists a certain optimal optical loss of the laser cavity at which the lowest heat-to-bitrate ratio is provided for any design of edge-emitting lasers that can be fabricated from an epitaxial structure. The heat-to-bitrate ratio and the corresponding bitrate are numerically calculated and analytical expressions are derived. It is demonstrated that the heat-to-bitrate ratio of quantum dot edge-emitting lasers can be less than 0.4 pJ/bit at a bitrate exceeding 10 Gbit/s.

Zhukov, A. E., E-mail: zhukale@gmail.com; Savelyev, A. V. [Russian Academy of Sciences, St. Petersburg Academic University-Nanotechnology Research and Education Center (Russian Federation)] [Russian Academy of Sciences, St. Petersburg Academic University-Nanotechnology Research and Education Center (Russian Federation); Maximov, M. V. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)] [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Kryzhanovskaya, N. V. [Russian Academy of Sciences, St. Petersburg Academic University-Nanotechnology Research and Education Center (Russian Federation)] [Russian Academy of Sciences, St. Petersburg Academic University-Nanotechnology Research and Education Center (Russian Federation); Gordeev, N. Yu.; Shernyakov, Yu. M. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)] [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Payusov, A. S.; Nadtochiy, A. M.; Zubov, F. I.; Korenev, V. V. [Russian Academy of Sciences, St. Petersburg Academic University-Nanotechnology Research and Education Center (Russian Federation)] [Russian Academy of Sciences, St. Petersburg Academic University-Nanotechnology Research and Education Center (Russian Federation)

2013-08-15T23:59:59.000Z

162

System Modeling of Gas Engine Driven Heat Pump  

SciTech Connect (OSTI)

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

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

2012-01-01T23:59:59.000Z

163

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

164

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  

SciTech Connect (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

165

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

E-Print Network [OSTI]

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

Bahrami, Majid

166

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

SciTech Connect (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

167

Minimal universal quantum heat machine  

E-Print Network [OSTI]

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

David Gelbwaser-Klimovsky; Robert Alicki; Gershon Kurizki

2012-09-06T23:59:59.000Z

168

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

SciTech Connect (OSTI)

Ground-based radar and lidar observations obtained at the Department of Energys Atmospheric Radiation Measurement Programs 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

169

Project Title: Small Scale Electrical Power Generation from Heat Co-Produced in Geothermal Fluids: Mining Operation  

SciTech Connect (OSTI)

Demonstrate the technical and economic feasibility of small scale power generation from low temperature co-produced fluids. Phase I is to Develop, Design and Test an economically feasible low temperature ORC solution to generate power from lower temperature co-produced geothermal fluids. Phase II &III are to fabricate, test and site a fully operational demonstrator unit on a gold mine working site and operate, remotely monitor and collect data per the DOE recommended data package for one year.

Clark, Thomas M [Principal Investigator; Erlach, Celeste [Communications Mgr.

2014-12-30T23:59:59.000Z

170

Industrial heat pumps - types and costs  

SciTech Connect (OSTI)

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

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

1985-08-01T23:59:59.000Z

171

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

172

Application of microwave heating to ceramic processing: Design and initial operation of a 2.45-GHz single-mode furnace  

SciTech Connect (OSTI)

High-power microwave and millimeter-wave sources are currently being applied to ceramic processing studies at the Naval Research Laboratory (NRL). A single-mode cavity microwave furnace, operating in the TE{sub 103} mode at 2.45 GHz, is operational and is being used to investigate sintering of nanocrystalline ceramics. This paper reports the design of the 2.45-GHz furnace and its use in initial microwave sintering experiments on nanocrystalline alumina and titania compacts. The high purity Al{sub 2}O{sub 3} and TiO{sub 2} nanocrystalline powders used in the sintering experiments were prepared by the sol-gel method. These powders were first uniaxially pressed to 14 MPa, cold isostatically pressed (CIP`ed) to various pressures {ge}420 MPa, and finally sectioned into wafers. The density of the green compacts was 30 to 38% theoretical density (TD). The compacts were placed in insulating fiberboard caskets which were sufficiently lossy to provide hybrid heating at room temperature. The compacts were heated in the microwave furnace for up to three hours at temperatures {ge}1720 C. The temperature of the workpiece was monitored using an optical pyrometer. Final densities up to 80% TD have been obtained to date for Al{sub 2}O{sub 3} and up to 52% TD for TiO{sub 2}. The sintered compacts were characterized by X-ray diffraction and by scanning electron microscopy (SEM) to determine the phase and grain size.

Fliflet, A.W. [Naval Research Lab., Washington, DC (United States)] [Naval Research Lab., Washington, DC (United States); Bruce, R.W.; Kinkead, A.K. [Sachs/Freeman Associates Inc., Landover, MD (United States)] [and others] [Sachs/Freeman Associates Inc., Landover, MD (United States); and others

1996-06-01T23:59:59.000Z

173

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

174

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

175

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

176

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

177

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...

Huang, Y.; Sun, D.

2006-01-01T23:59:59.000Z

178

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

SciTech Connect (OSTI)

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

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

2013-01-01T23:59:59.000Z

179

ARM - Measurement - Radiative heating rate  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUC : XDCResearch Relatedcontent ARMnumberDoppler ARM Data

180

Heat Treating Apparatus  

DOE Patents [OSTI]

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

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

2002-09-10T23:59:59.000Z

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

Geothermal heating for Caliente, Nevada  

SciTech Connect (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

182

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

183

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

184

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

185

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

SciTech Connect (OSTI)

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

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

1994-11-01T23:59:59.000Z

186

Geothermal heating  

SciTech Connect (OSTI)

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

Aureille, M.

1982-01-01T23:59:59.000Z

187

Methodology for Life Testing of Refractory Metal / Sodium Heat Pipes  

SciTech Connect (OSTI)

This work establishes an approach to generate carefully controlled data to find heat pipe operating life with material-fluid combinations capable of extended operation. To accomplish this goal acceleration is required to compress 10 years of operational life into 3 years of laboratory testing through a combination of increased temperature and mass fluence. Specific test series have been identified, based on American Society for Testing and Materials (ASTM) specifications, to investigate long-term corrosion rates. The refractory metal selected for demonstration purposes is a molybdenum-44.5% rhenium alloy formed by powder metallurgy. The heat pipes each have an annular crescent wick formed by hot isostatic pressing of molybdenum-rhenium wire mesh. The heat pipes are filled by vacuum distillation with purity sampling of the completed assembly. Round-the-clock heat pipe tests with 6-month destructive and non-destructive inspection intervals are conducted to identify the onset and level of corrosion. Non-contact techniques are employed to provide power to the evaporator (radio frequency induction heating at 1 to 5 kW per heat pipe) and calorimetry at the condenser (static gas gap coupled water cooled calorimeter). The planned operating temperature range extends from 1123 to 1323 K. Accomplishments before project cancellation included successful development of the heat pipe wick fabrication technique, establishment of all engineering designs, baseline operational test requirements, and procurement/assembly of supporting test hardware systems. (authors)

Martin, James J.; Reid, Robert S. [Marshall Space Flight Center, National Aeronautics and Space Administration, Huntsville, Alabama, 35812 (United States)

2006-07-01T23:59:59.000Z

188

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

SciTech Connect (OSTI)

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

Grossman, A S; Grant, K E

1992-11-16T23:59:59.000Z

189

Cab Heating and Cooling  

SciTech Connect (OSTI)

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

Damman, Dennis

2005-10-31T23:59:59.000Z

190

Dry/wet performance of a plate-fin air-cooled heat exchanger with continuous corrugated fins  

SciTech Connect (OSTI)

The performance and operating characteristics of a plate-fin heat exchanger in dry/wet or deluge operations was experimentally determined. Development of the deluge heat/mass transfer model continued. The experiments were conducted in a specially-designed wind tunnel at the PNL. Air that was first heated and humidified to specified conditions was circulated at a controlled rate through a 2 ft x 6 ft heat exchanger module. The heat exchanger used in the tests was a wavy surface, plate fin on tube configuration. Hot water was circulated through the tubes at high flow rates to maintain an essentially isothermal condition on the tube side. Deionized water sprayed on the top of the vertically oriented plate fins was collected at the bottom of the core and recirculated. Instrumentation was provided for measurement of flow rates and thermodynamic conditions in the air, in the core circulation water, and in the deluge water. Measurements of the air side pressure drop and heat rejection rate were made as a function of air flow rate, air inlet temperature and humidity, deluge water flow rate, and the core inclination from the vertical. An overall heat transfer coefficient and an effective deluge film convective coefficient was determined. The deluge model, for predicting heat transfer from a wet finned heat exchanger was further developed and refined, and a major extension of the model was formulated that permits simultaneous calculation of both the heat transfer and evaporation rates from the wetted surface. The experiments showed an increase in the heat rejection rate due to wetting, accompanied by a proportional increase in the air side pressure drop. For operation at the same air side pressure drop, the enhancement ratio Q/sub w//Q/sub d/ varied between 2 and 5 for the conditions tested. Thus, the potential enhancement of heat transfer due to wetting can be substantial.

Hauser, S.G.; Kreid, D.K.; Johnson, B.M.

1981-01-01T23:59:59.000Z

191

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

192

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

193

Capture of Heat Energy from Diesel Engine Exhaust  

SciTech Connect (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

194

Finding of No Significant Impact and Final Environmental Assessment for the Future Location of Heat Source/Radioisotope Power System Assembly and Testing and Operations Currently Located at the Mound Site  

SciTech Connect (OSTI)

The U.S. Department of Energy (the Department) has completed an Environmental Assessment for the Future Location of the Heat Source/Radioisotope Power System Assembly and Test. Operations Currently Located at the Mound Site. Based on the analysis in the environmental assessment, the Department has determined that the proposed action, the relocation of the Department's heat source and radioisotope power system operations, does not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the ''National Environmental Policy Act'' of 1969 (NEPA). Therefore, the preparation of an Environmental Impact Statement is not required, and the Department is issuing this Finding of No Significant Impact (FONSI).

N /A

2002-08-30T23:59:59.000Z

195

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

196

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

SciTech Connect (OSTI)

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

197

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

198

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...

Murray, F.

1984-01-01T23:59:59.000Z

199

Challenges in Industrial Heat Recovery  

E-Print Network [OSTI]

This presentation will address several completed and working projects involving waste heat recovery in a chemical plant. Specific examples will be shown and some of the challenges to successful implementation and operation of heat recovery projects...

Dafft, T.

2007-01-01T23:59:59.000Z

200

TRANSPARENT HEAT MIRRORS FOR PASSIVE SOLAR HEATING APPLICATIONS  

E-Print Network [OSTI]

heating purposes. BACKGROUND The reduction of heat transfer rates by the use of thermal infraredheating applications should become available on the marketplace. Due to their high reflectivity to thermal infrared

Selkowitz, S.

2011-01-01T23:59:59.000Z

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

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

202

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

203

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

SciTech Connect (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

204

Heat-transfer coefficients in agitated vessels. Latent heat models  

SciTech Connect (OSTI)

Latent heat models were developed to calculate heat-transfer coefficients in agitated vessels for two cases: (1) heating with a condensable fluid flowing through coils and jackets; (2) vacuum reflux cooling with an overhead condenser. In either case the mathematical treatment, based on macroscopic balances, requires no iterative schemes. In addition to providing heat-transfer coefficients, the models predict flow rates of service fluid through the coils and jackets, estimate the percentage of heat transfer due to latent heat, and compute reflux rates.

Kumpinsky, E. [Ashland Chemical Co., Columbus, OH (United States)] [Ashland Chemical Co., Columbus, OH (United States)

1996-03-01T23:59:59.000Z

205

Cogeneration Operational Issues  

E-Print Network [OSTI]

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...

Williams, M.

206

Heat Transfer Enhancement for Finned-tube Heat Exchangers with Winglets  

SciTech Connect (OSTI)

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

O'Brien, James Edward; Sohal, Manohar Singh

2000-11-01T23:59:59.000Z

207

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

SciTech Connect (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

208

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

209

Heat and mass exchanger  

DOE Patents [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)

2007-09-18T23:59:59.000Z

210

Heat and mass exchanger  

DOE Patents [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

211

Industrial Heat Pump Case Study  

E-Print Network [OSTI]

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

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

212

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

213

Spring 2014 Heat Transfer -1  

E-Print Network [OSTI]

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

Virginia Tech

214

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

E-Print Network [OSTI]

for this air conditioner are to be sketched. The heat absorbed by the refrigerant, the work input of the air conditioner is 689.4 Btu/h3.412 W1 W Btu/h 16 Btu/h3.412 W1 SEERCOPR

Kostic, Milivoje M.

215

Refrigerant charge management in a heat pump water heater  

DOE Patents [OSTI]

Heat pumps that heat or cool a space and that also heat water, refrigerant management systems for such heat pumps, methods of managing refrigerant charge, and methods for heating and cooling a space and heating water. Various embodiments deliver refrigerant gas to a heat exchanger that is not needed for transferring heat, drive liquid refrigerant out of that heat exchanger, isolate that heat exchanger against additional refrigerant flowing into it, and operate the heat pump while the heat exchanger is isolated. The heat exchanger can be isolated by closing an electronic expansion valve, actuating a refrigerant management valve, or both. Refrigerant charge can be controlled or adjusted by controlling how much liquid refrigerant is driven from the heat exchanger, by letting refrigerant back into the heat exchanger, or both. Heat pumps can be operated in different modes of operation, and segments of refrigerant conduit can be interconnected with various components.

Chen, Jie; Hampton, Justin W.

2014-06-24T23:59:59.000Z

216

Proceedings: Heat exchanger workshop  

SciTech Connect (OSTI)

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

Not Available

1987-07-01T23:59:59.000Z

217

The World's First InP 8x8 Monolithic Tunable Optical Router (MOTOR) Operating at 40 Gbps Line Rate per Port  

E-Print Network [OSTI]

on the world's first 8-channel monolithic tunable optical router (MOTOR) operating at 40 Gbps per port. The InP/InGaAsP approach. This platform allowed us to reduce absorption losses in the AWGR and delay line regions

Coldren, Larry A.

218

NGNP Process Heat Utilization: Liquid Metal Phase Change Heat Exchanger  

SciTech Connect (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

219

Simulation study of a heat pump for simultaneous heating and cooling coupled to buildings  

E-Print Network [OSTI]

Simulation study of a heat pump for simultaneous heating and cooling coupled to buildings Redouane) 141-149" DOI : 10.1016/j.enbuild.2013.12.047 #12;ABSTRACT In several situations, a heat pump occur. Unlike a reversible heat pump that works alternatively in heating or cooling, a HPS operates

Paris-Sud XI, Université de

220

E-Print Network 3.0 - absorption-sorption heat pumps Sample Search...  

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

Corporation Auxiliary - Heat pump water heater 50... -gal tank, electric auxiliary heating Multiple operating modes: heat pump, hybrid and standard... and Ventilation Systems...

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

E-Print Network 3.0 - absorption-type heat pumps Sample Search...  

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

Corporation Auxiliary - Heat pump water heater 50... -gal tank, electric auxiliary heating Multiple operating modes: heat pump, hybrid and standard... and Ventilation Systems...

222

Rational analysis of mass, momentum, and heat transfer phenomena in liquid storage tanks under realistic operating conditions: 2. Application to a feasibility study  

SciTech Connect (OSTI)

This is the second part of a two-part paper that deals with modeling the thermal performances of storage tanks of liquid water coupled with solar-assisted heatpump systems. The computer code THESTA, described in detail in the first part, has been applied to compare configurations which differ from one another in the distribution and thickness of the insulating panels. These numerical experiments show very clearly the capability of the code in simulating realistic operating conditions. The validity of the present release is also discussed. The results obtained have been assumed to be a reliable theoretical support to the definition of the features of the storage device of a pilot plant.

Parrini, F.; Vitale, S. (ENEL-Italian National Electricity Board-CRTN, Milan (Italy)); Castellano, L. (MATEC S.r.l., Milan (Italy))

1992-08-01T23:59:59.000Z

223

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  

SciTech Connect (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

224

arabidopsis small heat: Topics by E-print Network  

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

wasted heat could be converted to useful power, it would Columbia University 369 Heat testing methodology comparison. Open Access Theses and Dissertations Summary: ??Pre-operative...

225

alter heat chock: Topics by E-print Network  

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

Summary: This paper discusses the design and operation of the Trane Weathertron III Heat Pump Water Heating System and includes a comparison of features and performance to other...

226

ampicillin increased heat: Topics by E-print Network  

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

Summary: This paper discusses the design and operation of the Trane Weathertron III Heat Pump Water Heating System and includes a comparison of features and performance to other...

227

Quantum heat engines and refrigerators: Continuous devices  

E-Print Network [OSTI]

Quantum thermodynamics supplies a consistent description of quantum heat engines and refrigerators up to the level of a single few level system coupled to the environment. Once the environment is split into three;a hot, cold and work reservoirs a heat engine can operate. The device converts the positive gain into power;where the gain is obtained from population inversion between the components of the device. Reversing the operation transforms the device into a quantum refrigerator. The quantum tricycle, a device connected by three external leads to three heat reservoirs is used as a template for engines and refrigerators. The equation of motion for the heat currents and power can be derived from first principle. Only a global description of the coupling of the device to the reservoirs is consistent with the first and second laws of thermodynamics. Optimisation of the devices leads to a balanced set of parameters where the couplings to the three reservoirs are of the same order and the external driving field is in resonance. When analysing refrigerators special attention is devoted to a dynamical version of the third law of thermodynamics. Bounds on the rate of cooling when approaching the absolute zero are obtained by optimising the cooling current. At low temperature all refrigerators show universal behavior. Restrictions on the system imposed by the dynamical version of the third law are studied.

Ronnie Kosloff; Amikam Levy

2013-10-02T23:59:59.000Z

228

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

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

Combined Heat and Power Systems for Boiler Owners and Operators Guide to Combined Heat and Power Systems for Boiler Owners and Operators This guide presents useful information for...

229

Study of Frost Growth on Heat Exchangers Used as Outdoor Coils in Air Source Heat Pump Systems.  

E-Print Network [OSTI]

??During winter heating operation, the outdoor coil of a heat pump acts as an evaporator and when the ambient temperature is near freezing, the moisture (more)

Padhmanabhan, Sankaranarayanan K.

2011-01-01T23:59:59.000Z

230

Emissions characteristics of modern oil heating equipment  

SciTech Connect (OSTI)

Over the last 10 years there have been some very interesting developments in oil heating. These include higher static pressure burners, air atomizing nozzles, low firing rate nozzles, low heat loss combustion chambers and condensing boilers and furnaces. The current data base on the emissions characteristics of oil-fired residential heating equipment is based primarily on data taken in the 1970's. The objective of the work described in this report is to evaluate the effects of recent developments in oil-fired equipment on emissions. Detailed emissions measurements have been made on a number of currently available residential oil burners and whole systems selected to represent recent development trends. Some additional data was taken with equipment which is in the prototype stage. These units are a prevaporizing burner and a retention head burner modified with an air atomizing nozzle. Measurements include No{sub x}, smoke numbers, CO, gas phase hydrocarbon emissions and particulate mass emission rates. Emissions of smoke, CO and hydrocarbons were found to be significantly greater under cyclic operation for all burners tested. Generally, particulate emission rates were found to be 3 to 4 times greater in cyclic operation than in steady state. Air atomized burners were found to be capable of operation at much lower excess air levels than pressure atomized burners without producing significant amounts of smoke. As burner performance is improved, either through air atomization or prevaporization of the fuel, there appears to be a general trend towards producing CO at lower smoke levels as excess air is decreased. The criteria of adjusting burners for trace smoke may need to be abandoned for advanced burners and replaced with an adjustment for specific excess air levels. 17 refs., 15 figs., 6 tabs.

Krajewski, R.; Celebi, Y.; Coughlan, R.; Butcher, T.; McDonald, R.J.

1990-07-01T23:59:59.000Z

231

Experimental investigation of piston heat transfer under conventional diesel and reactivity-controlled compression ignition combustion regimes  

SciTech Connect (OSTI)

The piston of a heavy-duty single-cylinder research engine was instrumented with 11 fast-response surface thermocouples, and a commercial wireless telemetry system was used to transmit the signals from the moving piston. The raw thermocouple data were processed using an inverse heat conduction method that included Tikhonov regularization to recover transient heat flux. By applying symmetry, the data were compiled to provide time-resolved spatial maps of the piston heat flux and surface temperature. A detailed comparison was made between conventional diesel combustion and reactivity-controlled compression ignition combustion operations at matched conditions of load, speed, boost pressure, and combustion phasing. The integrated piston heat transfer was found to be 24% lower, and the mean surface temperature was 25 C lower for reactivity-controlled compression ignition operation as compared to conventional diesel combustion, in spite of the higher peak heat release rate. Lower integrated piston heat transfer for reactivity-controlled compression ignition was found over all the operating conditions tested. The results showed that increasing speed decreased the integrated heat transfer for conventional diesel combustion and reactivity-controlled compression ignition. The effect of the start of injection timing was found to strongly influence conventional diesel combustion heat flux, but had a negligible effect on reactivity-controlled compression ignition heat flux, even in the limit of near top dead center high-reactivity fuel injection timings. These results suggest that the role of the high-reactivity fuel injection does not significantly affect the thermal environment even though it is important for controlling the ignition timing and heat release rate shape. The integrated heat transfer and the dynamic surface heat flux were found to be insensitive to changes in boost pressure for both conventional diesel combustion and reactivity-controlled compression ignition. However, for reactivity-controlled compression ignition, the mean surface temperature increased with changes in boost suggesting that equivalence ratio affects steady-state heat transfer.

Splitter, Derek A [ORNL; Hendricks, Terry Lee [Sandia National Laboratories (SNL); Ghandhi, Jaal B [University of Wisconsin

2014-01-01T23:59:59.000Z

232

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

Energy Savers [EERE]

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

233

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

234

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

235

Bioelectrochemical Integration of Waste Heat Recovery, Waste...  

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

electrolytic cell, designed to integrate waste heat recovery (i.e a microbial heat recovery cell or MHRC), can operate as a fuel cell and convert effluent streams into...

236

Absorptive Recycle of Distillation Waste Heat  

E-Print Network [OSTI]

condenser operates above ambient temperature, the rejected heat also contains unused availability. By incorporating an absorption heat pump (AHP) into the distillation process, these sources of unused availability can be tapped so as to recycle (and hence...

Erickson, D. C.; Lutz, E. J., Jr.

1982-01-01T23:59:59.000Z

237

Microchannel Heat Exchangers with Carbon Dioxide  

SciTech Connect (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

238

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

E-Print Network [OSTI]

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

239

Heat release rate markers for premixed combustion  

E-Print Network [OSTI]

1075. [21] Report: Hydrogen from Coal Program: Research, Development, and Demonstration Plan for the period 2008 through 2016. U.S. Department of Energy, 2008. [22] Report: Wabash River Coal Gasification re-powering Project: A DOE Assesment. U.S. Department... of Energy National Energy Technology Laboratory, 2002. [23] O. Maustard, Report: Massachusetts Institute of Technology Laboratory for Energy and the Environment, An Overview of Coal based Integrated Gasification Combined Cycle (IGCC) Technology, 2005. [24] R...

Nikolaou, Zacharias M.; Swaminathan, Nedunchezhian

2014-06-16T23:59:59.000Z

240

The Broadband Heating Rate Profile (BBHRP) VAP  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layered NbS2 and NbSe2 .2004The AtmosphericHomologous

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

Critical reaction rates in hypersonic combustion chemistry  

SciTech Connect (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

242

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

243

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

244

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

245

Evaluation of heat stress in an aluminum smelter  

E-Print Network [OSTI]

of heat stress and heat strain was evaluated for the aluminum smelter workers at Alcoa, Rockdale Operations. Personal, environmental, and metabolic factors that contribute to heat-related illnesses were identified. The effectiveness of current...

Rose, Stacy Rahkell

1999-01-01T23:59:59.000Z

246

`Heat pumps in Smart Grids' IEA Annex 42  

E-Print Network [OSTI]

facility Scandinavian interconnections Demand side Response (via smart grid) Industrial Residential.M. Wagener Managing Consultant OPERATING AGENT: #12;GAS HEAT PUMPS COMMERCIAL SECTOR RESEARCH, STRATEGY AUTOMATION HEAT PUMPS DOMESTIC AND COMMERCIAL BUILDINGS WORKING GROUP THERMAL DRIVEN HEAT PUMPS TARGET

Oak Ridge National Laboratory

247

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...

248

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...

249

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...

250

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...

251

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...

252

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

253

Modeling of ion heating from viscous damping of reconnection flows in the reversed field pinch  

SciTech Connect (OSTI)

Strong self-heating of ions is observed in the reversed field pinch (RFP). During a sawtooth crash in the Madison Symmetric Torus RFP, the ion temperature can spontaneously double in {approx}100 {mu}s. It is also observed that high Z impurities are heated more strongly than bulk ions. The possibility of ion heating due to tearing instabilities at sawtooth crash is examined. Heating scenarios due to viscous damping of strongly localized perpendicular and parallel flows driven in the vicinity of resonant surface in tearing mode are considered. Flow amplitudes and spatial scales are estimated from linear and nonlinear resistive magnetohydrodynamic modeling. The heating rates are found from kinetic models with different levels of approximation, up to solving kinetic equation with a Landau collision operator. Results show reasonable agreement of the modeled impurity heating rate with the experiment, while the estimated bulk ions heating is somewhat weaker than in the experiment. Further theoretical and experimental study are required for a more definite conclusion as to whether it is the main ion heating mechanism or if there is some other important ion heating scenario.

Svidzinski, V. A.; Fiksel, G.; Mirnov, V. V.; Prager, S. C. [Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas and University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

2008-06-15T23:59:59.000Z

254

Industrial Heat Pump Design Options  

E-Print Network [OSTI]

There are numerous industries that can incorporate heat pumps into their operations to save energy costs and payoff the investment in well under two years. Many of these industries can cut energy costs associated with evaporation by over 75...

Gilbert, J. S.

255

Heat strain and heat stress for workers wearing protective suits at a hazardous waste site  

SciTech Connect (OSTI)

In order to evaluate the effects of heat stress when full body protective suits are worn, heart rates, oral temperatures and environmental parameters were measured for five unacclimatized male workers (25-33 years of age) who performed sampling activities during hazardous waste clean-up operations. The protective ensembles included laminated PVC-Tyvec chemical resistant hood suits with rubber boots, gloves, full facepiece dual cartridge respirators and hard hats. For comparison, measurements also were performed when the men worked at a similar level of activity while they wore ordinary work clothes. A comparison of the heart rates for the men working with and without suits indicated that wearing the suits imposed a heat stress equivalent to adding 6/sup 0/ to 11/sup 0/C (11/sup 0/ to 20/sup 0/F) to the ambient WBGT index. A similar result was obtained by calculating the WBGT in the microclimate inside the suits and comparing it to the ambient WBGT. These results indicate the following: 1) there exists a significant risk of heat injury during hazardous waste work when full body protective clothing is worn, and 2) threshold limit values for heat stress established by the ACGIH must be lowered substantially before extending them to cover workers under these conditions.

Paull, J.M.; Rosenthal, F.S.

1987-05-01T23:59:59.000Z

256

Heating system  

SciTech Connect (OSTI)

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

Nishman, P.J.

1983-03-08T23:59:59.000Z

257

MIXED PHASE COMPRESSION HIGH EFFICIENCY HEAT PUMP.  

E-Print Network [OSTI]

??The objective of this thesis is the design and realization of a higher efficiency air source heat pump. The improved pump???s operating cost must rival (more)

Chan, WenYen

2014-01-01T23:59:59.000Z

258

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

259

Application Study of a Single House Horizontal Heating System  

E-Print Network [OSTI]

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

Hang, Y.; Ying, D.

2006-01-01T23:59:59.000Z

260

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

SciTech Connect (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.


261

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

SciTech Connect (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 800C. 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

262

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

263

Solar industrial process heat  

SciTech Connect (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

264

High Heat Flux Components Program  

SciTech Connect (OSTI)

Purpose is the development of the technologies necessary to design, build and operate high heat flux components such as actively cooled limiters, divertor collector plates, R.F. antennas, mirror end cells, mirror halo collectors, direct convertor collectors, and neutral beam dumps. These components require an integrated design that considers the plasma-materials interaction (PMI) issues, heat removal problems and materials issues (including possible low Z coatings and claddings). As a general definition, high heat flux components see heat fluxes ranging from 1 to 100 MW/m/sup 2/. Suitable materials include copper and copper alloys.

Whitley, J.B.

1983-01-01T23:59:59.000Z

265

ADVANCED HEAT EXCHANGERS USING TUNABLE NANOSCALE-MOLECULAR ASSEMBLY  

SciTech Connect (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

266

Methanol-based heat pump for solar heating, cooling, and storage. Phase III. Final report  

SciTech Connect (OSTI)

The reaction of CH/sub 3/OH vapor with solid (pellet) CaCl/sub 2/ to form the solid phase compound CaCll/sub 2/ . 2CH/sub 3/OH can be used as the basis of a combined solar heat pump/thermal energy storage system. Such a system is capable of storing heat indefinitely at ambient temperature, and can be used for space and domestic hot water heating, and for air conditioning with forced air (dry) heat rejection. It combines all features required of a residential or commercial space conditioning system except for solar collection. A detailed thermal analysis shows that the coefficient of performance for heating is greater than 1.5, and for cooling, greater than 0.5. This has been confirmed by direct experimental measurement on an engineering development test unit (EDTU). The experimental rate of CH/sub 3/OH absorption is a strong function of the absorber-evaporator temperature difference. The minimum practical hourly rate, 0.10 moles CH/sub 3/OH per mole CaCl/sub 2/, was observed with the salt-bed heat transfer fluid at 40/sup 0/C and the CH/sub 3/OH evaporator at -15/sup 0/C. a detailed performance and economic analysis was carried out for a system operated in Washington, DC. With 25 square meters of evacuated tube solar collectors, the CaCl/sub 2/-CH/sub 3/OH chemical heat pump should be capable of meeting over 90% of the cooling load, 80% of the heating load, and 70% of the domestic hot water load with nonpurchased energy in a typical well-insulated single family residence, thus saving about $600 per year. In small-scale production, the installed cost of the system, including solar collectors and backup, is estimated to be about $10,000 greater than a conventional heating and cooling system, and a much lower cost should be possible in the longer term.

Offenhartz, P O'D; Rye, T V; Malsberger, R E; Schwartz, D

1981-03-01T23:59:59.000Z

267

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

268

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

E-Print Network [OSTI]

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

Gaskill, Travis

2012-02-14T23:59:59.000Z

269

Rate Schedules  

Broader source: Energy.gov [DOE]

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

270

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

271

Development of an integrated building load and ground source heat pump model to assess heat pump and ground loop design and performance in a commercial office building.  

E-Print Network [OSTI]

??Ground source heat pumps (GSHPs) offer an efficient method for cooling and heating buildings, reducing energy usage and operating cost. In hot, arid regions such (more)

Blair, Jacob Dale

2014-01-01T23:59:59.000Z

272

Fact #659: January 24, 2011 Fuel Economy Ratings for Vehicles...  

Energy Savers [EERE]

9: January 24, 2011 Fuel Economy Ratings for Vehicles Operating on Electricity Fact 659: January 24, 2011 Fuel Economy Ratings for Vehicles Operating on Electricity The...

273

Multidisciplinary University Research Initiative: High Operating...  

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

University Research Initiative (MURI) to develop high-operating temperature heat-transfer fluids for concentrating solar power (CSP) applications. The following...

274

Heat transfer and pressure drop in an annular channel with downflow  

SciTech Connect (OSTI)

The onset of a flow instability (OFI) determines the minimum flow rate for cooling in the flow channels of a nuclear fuel assembly. A test facility was constructed with full-scale models (length and diameter) of annular flow channels incorporating many instruments to measure heat transfer and pressure drop with downflow in the annulus. Tests were performed both with and without axial centering ribs at prototypical values of pressure, flow rate and uniform wall heat flux. The axial ribs have the effect of subdividing the annulus into quadrants, so the problem becomes one of parallel channel flow, unlike previous experiments in tubes (upflow and downflow). Other tests were performed to determine the effects if any of asymmetric and non-uniform circumferential wall heating, operating pressure level and dissolved gas concentration. Data from the tests are compared with models for channel heat transfer and pressure drop profiles in several regimes of wall heating from single-phase forced convection through partially and fully developed nucleate boiling. Minimum stable flow rates were experimentally determined as a function of wall heat flux and heat distribution and compared with the model for the transition to fully developed boiling which is a key criterion in determining the OFI condition in the channel. The heat transfer results in the channel without ribs are in excellent agreement with predictions from a computer model of the flow in the annulus and with empirical correlations developed from similar tests. The test results with centering ribs show that geometrical variations between the channels can lead to differences in subchannel behavior which can make the effect of the ribs and the geometry an important factor when assessing the power level at which the fuel assembly (and the reactor) can be operated to prevent overheating in the event of a loss-of-coolant-accident (LOCA).

Dolan, F.X.; Crowley, C.J. [Creare, Inc., Hanover, NH (United States); Qureshi, Z.H. [Westinghouse Savannah River Co., Aiken, SC (United States)

1992-06-01T23:59:59.000Z

275

Heat transfer and pressure drop in an annular channel with downflow  

SciTech Connect (OSTI)

The onset of a flow instability (OFI) determines the minimum flow rate for cooling in the flow channels of a nuclear fuel assembly. A test facility was constructed with full-scale models (length and diameter) of annular flow channels incorporating many instruments to measure heat transfer and pressure drop with downflow in the annulus. Tests were performed both with and without axial centering ribs at prototypical values of pressure, flow rate and uniform wall heat flux. The axial ribs have the effect of subdividing the annulus into quadrants, so the problem becomes one of parallel channel flow, unlike previous experiments in tubes (upflow and downflow). Other tests were performed to determine the effects if any of asymmetric and non-uniform circumferential wall heating, operating pressure level and dissolved gas concentration. Data from the tests are compared with models for channel heat transfer and pressure drop profiles in several regimes of wall heating from single-phase forced convection through partially and fully developed nucleate boiling. Minimum stable flow rates were experimentally determined as a function of wall heat flux and heat distribution and compared with the model for the transition to fully developed boiling which is a key criterion in determining the OFI condition in the channel. The heat transfer results in the channel without ribs are in excellent agreement with predictions from a computer model of the flow in the annulus and with empirical correlations developed from similar tests. The test results with centering ribs show that geometrical variations between the channels can lead to differences in subchannel behavior which can make the effect of the ribs and the geometry an important factor when assessing the power level at which the fuel assembly (and the reactor) can be operated to prevent overheating in the event of a loss-of-coolant-accident (LOCA).

Dolan, F.X.; Crowley, C.J. (Creare, Inc., Hanover, NH (United States)); Qureshi, Z.H. (Westinghouse Savannah River Co., Aiken, SC (United States))

1992-01-01T23:59:59.000Z

276

AGN Heating through Cavities and Shocks  

E-Print Network [OSTI]

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

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

2006-11-04T23:59:59.000Z

277

The Hardy inequality and the heat equation with magnetic field in any dimension  

E-Print Network [OSTI]

In the Euclidean space of any dimension d, we consider the heat semigroup generated by the magnetic Schroedinger operator from which an inverse-square potential is subtracted in order to make the operator critical in the magnetic-free case. Assuming that the magnetic field is compactly supported, we show that the polynomial large-time behaviour of the heat semigroup is determined by the eigenvalue problem for a magnetic Schroedinger operator on the (d-1)-dimensional sphere whose vector potential reflects the behaviour of the magnetic field at the space infinity. From the spectral problem on the sphere, we deduce that in d=2 there is an improvement of the decay rate of the heat semigroup by a polynomial factor with power proportional to the distance of the total magnetic flux to the discrete set of flux quanta, while there is no extra polynomial decay rate in higher dimensions. To prove the results, we establish new magnetic Hardy-type inequalities for the Schroedinger operator and develop the method of self-similar variables and weighted Sobolev spaces for the associated heat equation.

Cristian Cazacu; David Krejcirik

2014-09-23T23:59:59.000Z

278

Transmission and Storage Operations  

Energy Savers [EERE]

to see minimal to none in static or dynamic mode) - Rates are dependent on size, mechanical wear and operating pressures * PM * PdM 5 Methane Release Reduction Can the gas be...

279

CH Packaging Operations Manual  

SciTech Connect (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

280

Heat transfer in the plate heat exchanger of an ammonia-synthesis column  

SciTech Connect (OSTI)

The planning and construction of high-capacity synthetic ammonia plants requires the development and fabrication of unique, high unit-power equipment with high technical and economic characteristics. In foreign and domestic practice, tubular heat exchangers with relatively low heat-transfer coefficients are used. Plate heat exchangers are a promising alternative. They are compact and have a high heat energy efficiency and a relatively small metal content. To make an experimental check of the operating capability of a plate heat exchanger under ammonia production conditions, a welded plate heat exchanger was designed for an ammonia synthesis column 800mm in diameter. On prolonged testing (four years), the device provided an autothermal operating mode in the column and the heat transfer coefficient was practically constant for fixed space velocities. Consequently, the heat exchange surface was not contaminated significantly with catalyst dust, confirmed by visual observation of the heat exchanger after disassembly.

Obolentsev, Y.G.; Chus', M.S.; Norobchanskii, O.A.; Teplitshi, Y.S.; Tovazhnyanskii, L.L.

1983-01-01T23:59:59.000Z

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.


281

Users Guide for Getter Rate Test System  

SciTech Connect (OSTI)

This Users 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

282

Heating System Specification Specification of Heating System  

E-Print Network [OSTI]

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

Day, Nancy

283

Heat exchanger for power generation equipment  

DOE Patents [OSTI]

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

Nirmalan, Nirm Velumylm; Bowman, Michael John

2005-06-14T23:59:59.000Z

284

Liquid metal heat exchanger for efficient heating of soils and geologic formations  

DOE Patents [OSTI]

Apparatus for efficient heating of subterranean earth includes a well-casing that has an inner wall and an outer wall. A heater is disposed within the inner wall and is operable within a preselected operating temperature range. A heat transfer metal is disposed within the outer wall and without the inner wall, and is characterized by a melting point temperature lower than the preselected operating temperature range and a boiling point temperature higher than the preselected operating temperature range.

DeVault, Robert C. (Knoxville, TN) [Knoxville, TN; Wesolowski, David J. (Kingston, TN) [Kingston, TN

2010-02-23T23:59:59.000Z

285

Dealing with big circulation flow, small temperature difference based on verified dynamic model simulations of a hot water district heating system  

E-Print Network [OSTI]

DEALING WITH BIG CIRCULATION FLOW RATE, SMALL TEMPERATURE DIFFERENCE BASED ON VERIFIED DYNAMIC MODEL SIMULATIONS OF A HOT WATER DISTRICT HEATING SYSTEM Li Lian Zhong, Senior Sales Consultant, Danfoss Automatic Controls Management (Shanghai...) Co.,Ltd, Anshan, China ABSTRACT Dynamic models of an indirect hot water district heating system were developed based on the first principle of thermodynamics. The ideal model was verified by using measured operational data. The ideal...

Zhong, L.

2014-01-01T23:59:59.000Z

286

Modeling of Heat Transfer in Geothermal Heat Exchangers  

E-Print Network [OSTI]

, University of Lund, Sweden, [7] Fang, Z., Diao, N., and Cui, P., Discontinuous operation of geothermal heat exchangers [J], Tsinghua Science and Technology. , 2002, 7 194?197. [8] Hellstrom, G., Ground heat storage -- Thermal analysis of duct storage... systems [D], Department of Mathem Sweden, 1991. [9] Mei, V. C. and Baxter, V. D., Performance of a ground-coupled heat pump with multiple dissimilar U-tu Transactions, 1986, 92 Part 2, 22-25. [10] Yavuzturk, C., Spitler, J. D. and Rees, S. J., A...

Cui, P.; Man, Y.; Fang, Z.

2006-01-01T23:59:59.000Z

287

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

288

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

289

Laboratory Performance Evaluation of Residential Integrated Heat Pump Water Heaters  

SciTech Connect (OSTI)

This paper explores the laboratory performance of five integrated Heat Pump Water Heaters (HPWHs) across a wide range of operating conditions representative of US climate regions. HPWHs are expected to provide significant energy savings in certain climate zones when compared to typical electric resistance water heaters. Results show that this technology is a viable option in most climates, but differences in control schemes and design features impact the performance of the units tested. Tests were conducted to map heat pump performance across the operating range and to determine the logic used to control the heat pump and the backup electric heaters. Other tests performed include two unique draw profile tests, reduced air flow performance tests and the standard DOE rating tests. The results from all these tests are presented here for all five units tested. The results of these tests will be used to improve the EnergyPlus heat pump water heater for use in BEopt(tm) whole-house building simulations.

Sparn, B.; Hudon, K.; Christensen, D.

2014-06-01T23:59:59.000Z

290

www.heatpumpcentre.org IEA HEAT PUMP PROGRAMME  

E-Print Network [OSTI]

for buildings in cold climates Annex 40 - Heat pump concepts for near zero- energy buildings (Operating Agent boilers and gas boilers Annex 38 - Systems using solar thermal energy in combination with heat pumps (Operating Agent: CH) The aim is to analyse solar and heat pump configurations with respect to energy savings

Oak Ridge National Laboratory

291

Operating temperatures for a convectively cooled recessed incandescent light fixture  

SciTech Connect (OSTI)

Test results are given for the operation of a recessed incandescent light fixture intended for residential use. The fixture is labeled for use in direct contact with attic thermal insulation. Temperature control of the powered fixture is provided by convective heat transfer from the ceiling side of the fixture. The fixture was operated at power levels up to two times the rated power of 75 watts and under thermal insulations up to R-40. In all operating configurations tested the fixture surface in contact with attic insulation was found to be less than 175/sup 0/C. The observed surface temperatures are judged to be safe for operation in contact with loose-fill or batt-type insulations. It was observed that the power leads inside one fixture configuration are exposed to temperatures as high as 168/sup 0/C. The electrical insulation could, therefore, have a limited life. The properties of the internal fixture wiring were not, however, studied in detail.

Yarbrough, D.W.; Toor, I.

1980-12-01T23:59:59.000Z

292

BWR spent fuel storage cask performance test. Volume 2. Pre- and post-test decay heat, heat transfer, and shielding analyses  

SciTech Connect (OSTI)

This report describes the decay heat, heat transfer, and shielding analyses conducted in support of performance testing of a Ridhihalgh, Eggers and Associates REA 2033 boiling water reactor (BWR) spent fuel storage cask. The cask testing program was conducted for the US Department of Energy (DOE) Commercial Spent Fuel Management Program by the Pacific Northwest Laboratory (PNL) and by General Electric at the latters' Morris Operation (GE-MO) as reported in Volume I. The analyses effort consisted of performing pretest calculations to (1) select spent fuel for the test; (2) symmetrically load the spent fuel assemblies in the cask to ensure lateral symmetry of decay heat generation rates; (3) optimally locate temperature and dose rate instrumentation in the cask and spent fuel assemblies; and (4) evaluate the ORIGEN2 (decay heat), HYDRA and COBRA-SFS (heat transfer), and QAD and DOT (shielding) computer codes. The emphasis of this second volume is on the comparison of code predictions to experimental test data in support of the code evaluation process. Code evaluations were accomplished by comparing pretest (actually pre-look, since some predictions were not completed until testing was in progress) predictions with experimental cask testing data reported in Volume I. No attempt was made in this study to compare the two heat transfer codes because results of other evaluations have not been completed, and a comparison based on one data set may lead to erroneous conclusions.

Wiles, L.E.; Lombardo, N.J.; Heeb, C.M.; Jenquin, U.P.; Michener, T.E.; Wheeler, C.L.; Creer, J.M.; McCann, R.A.

1986-06-01T23:59:59.000Z

293

Enhanced heat transfer for thermionic power modules  

SciTech Connect (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

294

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

295

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

2001-04-17T23:59:59.000Z

296

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

297

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

298

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...

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

2006-01-01T23:59:59.000Z

299

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

SciTech Connect (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

300

A heat engine with unique characteristics  

SciTech Connect (OSTI)

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

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

1996-12-31T23:59:59.000Z

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.


301

TEELINDUSTRIAL OPERATING INSTRUCTIONS & PARTS MANUAL  

E-Print Network [OSTI]

-stage zoning applications in hydronic heating and cooling systems for residential, commercial and/or inTEELINDUSTRIAL SERIES OPERATING INSTRUCTIONS & PARTS MANUAL WATER CIRCULATING PUMPS MODELS 1P899A INSTRUCTIONS CAREFULLY BEFORE ATTEMPTING TO INSTALL, OPERATE, OR SERVICE TEEL PUMPS. PROTECT YOURSELF

Kleinfeld, David

302

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

303

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

SciTech Connect (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

304

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

305

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

306

Proceedings of HT'03 2003 Summer Heat Transfer Conference  

E-Print Network [OSTI]

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

Walker, D. Greg

307

Stirling cycle engine and heat pump  

SciTech Connect (OSTI)

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

Mitchell, M.P.

1986-11-18T23:59:59.000Z

308

MEASUREMENT OF SPECIFIC HEAT CAPACITY OF SALTSTONE  

SciTech Connect (OSTI)

One of the goals of the Saltstone variability study is to identify (and quantify the impact of) the operational and compositional variables that control or influence the important processing and performance properties of Saltstone grout mixtures. The heat capacity of the Saltstone waste form is one of the important properties of Saltstone mixes that was last measured at SRNL in 1997. It is therefore important to develop a core competency for rapid and accurate analysis of the specific heat capacity of the Saltstone mixes in order to quantify the impact of compositional and operational variations on this property as part of the variability study. The heat capacity, coupled with the heat of hydration data obtained from isothermal calorimetry for a given Saltstone mix, can be used to predict the maximum temperature increase in the cells within the vaults of the Saltstone Disposal Facility (SDF). The temperature increase controls the processing rate and the pour schedule. The maximum temperature is also important to the performance properties of the Saltstone. For example, in mass pours of concrete or grout of which Saltstone is an example, the maximum temperature increase and the maximum temperature difference (between the surface and the hottest location) are controlled to ensure durability of the product and prevent or limit the cracking caused by the thermal gradients produced during curing. This report details the development and implementation of a method for the measurement of the heat capacities of Saltstone mixes as well as the heat capacities of the cementitious materials of the premix and the simulated salt solutions used to batch the mixes. The developed method utilizes the TAM Air isothermal calorimeter and takes advantage of the sophisticated heat flow measurement capabilities of the instrument. Standards and reference materials were identified and used to validate the procedure and ensure accuracy of testing. Heat capacities of Saltstone mixes were {approx} 55% higher than the previous measurement of specific heat capacity on a reference Saltstone mix in 1997. Values of mixes prepared using Deliquification, Dissolution and Adjustment (DDA), Modular Caustic Side Solvent Extraction Unit (MCU) and Salt Waste Processing Facility (SWPF) simulants and premix at 0.60 w/cm ratio were {approx} 1.95 J/g/{sup o}C and were equivalent within experimental error. The simple law of mixtures was used to predict the heat capacities of the Saltstone and the results were in excellent agreement with experimental data. This simple law of mixtures can therefore be used to predict the heat capacities of Saltstone mixes in those cases where measurements have not been made. The time dependence of the heat capacity is important as an input to the modeling of temperature increase in Saltstone vaults. The heat capacity of a mix of MCU and premix at 0.60 w/cm ratio was measured immediately after initial mixing and then periodically up to times greater than 100 days. Within experimental error, the heat capacity did not change with time. Therefore, the modeling is not complicated by requiring a time dependent function for specific heat capacity. The water to cementitious material (w/cm) ratio plays a key role in determining the value of the heat capacity. Both experimental and predictive values for SWPF mixes as function of the w/cm ratio were obtained and presented in this report. Predictions of the maximum temperatures of the Saltstone mixes were made using the heat of hydration data from previous isothermal measurements and the newly measured heat capacities for DDA, MCU and SWPF mixes. The maximum temperature increase ranged from 37 to 48 C for these mixes. The presence of aluminate at 0.33 M produced a temperature increase of 68 C which is close to the adiabatic temperature rise of 74 C observed by Steimke and Fowler in 1997 for a mix containing 0.35 M aluminate. Aluminum dissolution of the sludge will increase the aluminate in the DSS which in turn will result in a larger temperature increase in the Saltstone vaults during the curing p

Harbour, J; Vickie Williams, V

2008-09-29T23:59:59.000Z

309

Designing, testing, and analyzing coupled, flux transformer heat  

E-Print Network [OSTI]

of identical effective length, this research shows that sufficient heat can be transferred across the system to work effectively in situations where the single heat pie will fail to operate. The thermal resistance in the condenser and evaporator sections need...

Renzi, Kimberly Irene

1998-01-01T23:59:59.000Z

310

Thermodynamic optimization of heat-driven refrigerators in the transient regime  

SciTech Connect (OSTI)

The present work introduces a transient endoreversible model of a heat-driven refrigeration plant, which is driven by a fuel-burning heater. The model consists of a combustion chamber with negligible heat loss to the ambient, a refrigerator with three finite-size heat exchangers, namely, the evaporator between the refrigeration load and refrigerant, the condenser between the refrigerant and the ambient, and the generator between the combustion chamber and the refrigerant, and finally the refrigerated space. The total thermal conductance of the three heat exchangers is fixed. A thermodynamic optimization of the absorption cycle is then performed, reporting the operating conditions for minimum time to reach a prescribed cold-space temperature, thus maximum refrigeration rate, specifically, the optimal mass fuel flow rate and the optimal way of allocating the thermal conductance inventory. Half of the total supply of thermal conductance has to be divided equally between the generator and evaporator and the other half allocated to the condenser, for optimal operation. A narrow range of fuel flow rates lead to the minimum time to achieve a prescribed cold-space temperature, thus stressing the importance of the transient analysis. Appropriate dimensionless groups were identified and the generalized results are reported in dimensionless charts.

Vargas, J.V.C.; Parise, J.A.R.; Ledezma, G.A.; Bianchi, M.V.A.

2000-02-01T23:59:59.000Z

311

Optimal operation of simple vapour compression cycles  

E-Print Network [OSTI]

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

Skogestad, Sigurd

312

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

SciTech Connect (OSTI)

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

Kudlac, G.A.

1998-06-01T23:59:59.000Z

313

A new cascade-type heat conversion system  

SciTech Connect (OSTI)

Various heat conversion systems have different operating temperatures. This paper shows how, in a solar energy system some of the waste heat from a thermophotovoltaic arrangement can be made to operate a thermionic power generator. The waste heat of the thermionic power generator can then be made to operate an alkali-metal thermal electric converter, and the waste heat from the alkali-metal thermal electric converter as well as the rest of the waste heat of the thermophotovoltaic system can be made to operate a methane reformation system. Stored heat from the methane reformation system can be made to operate the system at night. The overall system efficiency of the example shown is 42.6%. As a prime source of heat a nuclear pile or burning hydrogen may be used.

Newman, E. [Twenty-First Century Power Co., Northridge, CA (United States)

1996-12-31T23:59:59.000Z

314

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

E-Print Network [OSTI]

Efficiency Ratings for the Daiken AC (Americas), Inc. Altherma Air-to-Water Source Heat Pump System is used to provide water heating, the EF for that separate water heater shall be used for performance Description Model No. Capacity (tons) Space Heating Space Cooling SEER Water Heating Efficiency

315

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

316

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...

Ruch, M. A.

1981-01-01T23:59:59.000Z

317

Heat Integration and Heat Recovery at a Large Chemical Manufacturing Plant  

E-Print Network [OSTI]

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

Togna, K .A.

2012-01-01T23:59:59.000Z

318

Investigation of a radiantly heated and cooled office with an integrated desiccant ventilation unit  

E-Print Network [OSTI]

Radiant heating and cooling has a reputation of increasing the comfort level and reducing the energy consumption of buildings. The main advantages of radiant heating and cooling are low operational noise and reduced fan power cost. Radiant heating...

Gong, Xiangyang

2009-05-15T23:59:59.000Z

319

Heating systems for heating subsurface formations  

DOE Patents [OSTI]

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

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

2011-04-26T23:59:59.000Z

320

DCO Operations Interesting Statistics  

E-Print Network [OSTI]

DCO Operations Interesting Statistics 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com 1.00 0.95 0.90 0.85 0.80 0.75 0.70 0.65 0.60 0 is annotated with the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE

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

Ultra high vacuum heating and rotating specimen stage  

DOE Patents [OSTI]

A heating and rotating specimen stage provides for simultaneous specimen heating and rotating. The stage is ideally suited for operation in ultrahigh vacuum (1{times}10{sup {minus}9} torr or less), but is useful at atmosphere and in pressurized systems as well. A specimen is placed on a specimen holder that is attached to a heater that, in turn, is attached to a top housing. The top housing is rotated relative to a bottom housing and electrically connected thereto by electrically conductive brushes. This stage is made of materials that are compatible with UHV, able to withstand high temperatures, possess low outgassing rates, are gall and seize resistant, and are able to carry substantial electrical loading without overheating. 5 figs.

Coombs, A.W. III

1995-05-02T23:59:59.000Z

322

Heating and Cooling Equipment Selection  

SciTech Connect (OSTI)

This is one of a series of technology fact sheets created to help housing designers and builders adopt a whole-house design approach and energy efficient design practices. The fact sheet helps people choose the correct equipment for heating and cooling to reduce initial costs, increase homeowner comfort, increase operating efficiency, and greatly reduce utility costs.

Not Available

2002-01-01T23:59:59.000Z

323

Heat exchanger  

DOE Patents [OSTI]

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

Brackenbury, P.J.

1983-12-08T23:59:59.000Z

324

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

325

Heat transport system, method and material  

DOE Patents [OSTI]

A heat transport system, method and composite material are disclosed 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. 1 fig.

Musinski, D.L.

1987-04-28T23:59:59.000Z

326

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

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

Guide to Combined Heat and Power Systems for Boiler Owners and Operators, July 2004 Guide to Combined Heat and Power Systems for Boiler Owners and Operators, July 2004 Many owners...

327

Assessing the Thermal Environmental Impacts of an Groundwater Heat Pump in Southeastern Washington State  

SciTech Connect (OSTI)

A thermal analysis of a large-scale (e.g., 1900 gpm), open-loop ground source heat pump (GSHP) installed on the Pacific Northwest National Laboratory (PNNL) campus in southeastern Washington State has been performed using a numerical modeling approach. Water temperature increases at the upgradient extraction wells in the system and at the downgradient Columbia River are potential concerns, especially since heat rejection to the subsurface will occur year-round. Hence, thermal impacts of the open-loop GSHP were investigated to identify operational scenarios that minimized downgradient environmental impacts at the river, and upgradient temperature drift at the production wells. Simulations examined the sensitivity of the system to variations in pumping rates and injected water temperatures, as well as to hydraulic conductivity estimates of the aquifer. Results demonstrated that both downgradient and upgradient thermal impacts were more sensitive to injection flow rates than estimates of hydraulic conductivity. Higher injection rates at lower temperatures resulted in higher temperature increases at the extraction wells but lower increases at the river. Conversely, lower pumping rates and higher injected water temperatures resulted in a smaller temperature increase at the extraction wells, but higher increases at the river. The scenario with lower pumping rates is operationally more efficient, but does increase the likelihood of a thermal plume discharging into the Columbia River. However, this impact would be mitigated by mixing within the hyporheic zone and the Columbia River. The impact under current operational conditions is negligible, but future increases in heat rejection could require a compromise between maximizing operational efficiency and minimizing temperature increases at the shoreline.

Freedman, Vicky L.; Waichler, Scott R.; Mackley, Rob D.; Horner, Jacob A.

2012-04-01T23:59:59.000Z

328

Segmented heat exchanger  

DOE Patents [OSTI]

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

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

2010-12-14T23:59:59.000Z

329

Development of a compensation chamber for use in a multiple condenser loop heat pipe  

E-Print Network [OSTI]

The performance of many electronic devices is presently limited by heat dissipation rates. One potential solution lies in high-performance air-cooled heat exchangers like PHUMP, the multiple condenser loop heat pipe presented ...

Roche, Nicholas Albert

2013-01-01T23:59:59.000Z

330

Passive heat-transfer means for nuclear reactors. [LMFBR  

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. By having many such heat pipes, an emergency passive cooling system is defined that is operative without electrical power.

Burelbach, J.P.

1982-06-10T23:59:59.000Z

331

VARIABLE FIRING RATE OIL BURNER USING PULSE FUEL FLOW CONTROL.  

SciTech Connect (OSTI)

The residential oil burner market is currently dominated by the pressure-atomized retention head burner, which has an excellent reputation for reliability and efficiency. In this burner, oil is delivered to a fuel nozzle at pressures from 100 to 150 psi. In addition, to atomizing the fuel, the small, carefully controlled size of the nozzle exit orifice serves to control the burner firing rate. Burners of this type are currently available at firing rates of more than 0.5 gallons-per-hour (70,000 Btu/hr). Nozzles have been made for lower firing rates, but experience has shown that such nozzles suffer rapid fouling of the necessarily small passages, leading to bad spray patterns and poor combustion performance. Also, traditionally burners and the nozzles are oversized to exceed the maximum demand. Typically, this is figured as follows. The heating load of the house on the coldest day for the location is considered to define the maximum heat load. The contractor or installer adds to this to provide a safety margin and for future expansion of the house. If the unit is a boiler that provides domestic hot water through the use of a tankless heating coil, the burner capacity is further increased. On the contrary, for a majority of the time, the heating system is satisfying a much smaller load, as only rarely do all these demands add up. Consequently, the average output of the heating system has to be much less than the design capacity and this is accomplished by start and stop cycling operation of the system so that the time-averaged output equals the demand. However, this has been demonstrated to lead to overall efficiencies lower than the steady-state efficiency. Therefore, the two main reasons for the current practice of using oil burners much larger than necessary for space heating are the unavailability of reliable low firing rate oil burners and the desire to assure adequate input rate for short duration, high draw domestic hot water loads. One approach to solve this problem is to develop a burner, which can operate at two firing rates, with the lower rate being significantly lower than 0.5 gallons per hour. This paper describes the initial results of adopting this approach through a pulsed flow nozzle. It has been shown that the concept of flow modulation with a small solenoid valve is feasible. Especially in the second configuration tested, where the Lee valve was integrated with the nozzle, reasonable modulation in flow of the order of 1.7 could be achieved. For this first prototype, the combustion performance is still not quite satisfactory. Improvements in operation, for example by providing a sharp and positive shut-off so that there is no flow under low pressures with consequent poor atomization could lead to better combustion performance. This could be achieved by using nozzles that have shut off or check valves for example. It is recommended that more work in cooperation with the valve manufacturer could produce a technically viable system. Marketability is of course a far more complex problem to be addressed once a technically viable product is available.

KRISHNA,C.R.; BUTCHER,T.A.; KAMATH,B.R.

2004-10-01T23:59:59.000Z

332

Heating 7. 2 user's manual  

SciTech Connect (OSTI)

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

Childs, K.W.

1993-02-01T23:59:59.000Z

333

System for controlling the operating temperature of a fuel cell  

DOE Patents [OSTI]

A method and system are provided for improved control of the operating temperature of a fuel cell (32) utilizing an improved temperature control system (30) that varies the flow rate of inlet air entering the fuel cell (32) in response to changes in the operating temperature of the fuel cell (32). Consistent with the invention an improved temperature control system (30) is provided that includes a controller (37) that receives an indication of the temperature of the inlet air from a temperature sensor (39) and varies the heat output by at least one heat source (34, 36) to maintain the temperature of the inlet air at a set-point Tinset. The controller (37) also receives an indication of the operating temperature of the fuel cell (32) and varies the flow output by an adjustable air mover (33), within a predetermined range around a set-point Fset, in order to maintain the operating temperature of the fuel cell (32) at a set-point Topset.

Fabis, Thomas R.; Makiel, Joseph M.; Veyo, Stephen E.

2006-06-06T23:59:59.000Z

334

Heat loss from an open cavity  

SciTech Connect (OSTI)

Cavity type receivers are used extensively in concentrating solar thermal energy collecting systems. The Solar Total Energy Project (STEP) in Shenandoah, Georgia is a large scale field test for the collection of solar thermal energy. The STEP experiment consists of a large field array of solar collectors used to supplement the process steam, cooling and other electrical power requirements of an adjacent knitwear manufacturing facility. The purpose of the tests, conducted for this study, was to isolate and quantify the radiative, conductive, and convective components of total heat loss, and to determine the effects of operating temperature, receiver angle, and aperture size on cavity heat loss. An analytical model for radiative heat loss was developed and compared with two other methods used to determine radiative heat loss. A proposed convective heat loss correlation, including effects of aperture size, receiver operating temperature, and receiver angle is presented. The resulting data is a source to evaluate the STEP measurements.

McDonald, C.G. [California State Polytechnic Univ., Pomona, CA (United States). Coll. of Engineering

1995-12-01T23:59:59.000Z

335

Control Dewar Subcooler Heat Exchanger Calculations  

SciTech Connect (OSTI)

The calculations done to size the control dewar subcooler were done to obtain a sufficient subcooler size based on some conservative assumptions. The final subcooler design proposed in the design report will work even better because (1) It has more tubing length, and (2) will have already subcooled liquid at the inlet due to the transfer line design. The subcooler design described in the 'Design Report of the 2 Tesla Superconducting Solenoid for the Fermilab D0 Detector Upgrade' is the final design proposed. A short description of this design follows. The subcooler is constructed of 0.50-inch OD copper tubing with 1.0-inch diameter fins. It has ten and one half spirals at a 11.375-inch centerline diameter to provide 31 feet of tubing length. The liquid helium supply for the solenoid flows through the subcooler and then is expanded through a J-T valve. The subcooler spirals are immersed in the return two phase helium process stream. The return stream is directed over the finned tubing by an annulus created by a 10-inch pipe inside a 12-inch pipe. The transfer line from the refrigerator to the control dewar is constructed such that the liquid helium supply tube is in the refrigerator return stream, thereby subcooling the liquid up to the point where the u-tubes connect the transfer line to the control dewar. The subcooler within the control dewar will remove the heat picked up in the helium supply u-tube/bayonets. The attached subcooler/heat exchanger calculations were done neglecting any subcooling in the transfer line. All heat picked up in the transfer line from the refrigerator storage dewar to the control dewar is absorbed by the supply stream. The subcooler was sized such that the two phase supply fluid is subcooled at 1.7 atm pressure and when expanded through a JT valve to 1.45 atm pressure it is at a saturated liquid state. The calculations apply during steady state operation and at a flow rate of 16 g/s. The analysis of the heat exchanger was broken into two parts relating to the heat transfer mode taking place. The first part is considered the condensing part in which the helium supply stream is changed from two phase fluid to one phase liquid. The second part is the subcooling part where the liquid temperature is lowered, i.e.. subcooled. A summary of the calculations and results appears on the next page. The raw calculations follow the summary.

Rucinski, R.; /Fermilab

1993-10-04T23:59:59.000Z

336

Heat Treatment Procedure Qualification for Steel Castings  

SciTech Connect (OSTI)

The science of heat treatment has been well studied and is the basis from which existing specifications and practices for the heat treatment of steel castings have been developed. Although these existing specifications address the general needs of steel castings to be heat-treated, they do not take into account the variability in the parameters that govern the processes. The need for a heat treatment qualification procedure that accounts for this variability during heat treatment is an important step toward heat treatment quality assurance. The variability in temperatures within a heat treatment furnace is one such variable that a foundry has to contend with in its day-to-day activity. Though specifications indicate the temperatures at which a particular heat treatment has to be conducted, heat treatment specifications do not adequately account for all aspects of heat treatment quality assurance. The heat treatment qualification procedure will comprise of a robust set of rules and guidelines that ensure that foundries will still be able to operate within the set of constraints imposed on them by non-deterministic elements within the processes.

Professor Robert C. Voigt

2003-02-02T23:59:59.000Z

337

Materials, Turbomachinery and Heat Exchangers for Supercritical CO2 Systems  

SciTech Connect (OSTI)

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

Mark Anderson; Greg Nellis; Michael Corradini

2012-10-19T23:59:59.000Z

338

NREL Documents Efficiency of Mini-Split Heat Pumps (Fact Sheet)  

SciTech Connect (OSTI)

A new report delivers mini-split heat pump (MSHP) performance data for use in whole-building simulation tools. Mini-split heat pumps (MSHPs) are highly efficient refrigerant-based air conditioning and heating systems that permit room-by-room conditioning and control in homes. Because of their size, efficiency, and price, MSHPs are very popular overseas and are gaining market share in energy-efficient home upgrades in the United States. They are a good option for retrofitting older homes that lack ductwork. To evaluate MSHP cost effectiveness and performance in U.S. homes, National Renewable Energy Laboratory (NREL) researchers are studying these systems in the laboratory, simulated buildings, and field test settings. A new NREL report describes an innovative laboratory approach to testing MSHPs and includes experimental performance maps for use in whole-building simulation tools. Most public information on MSHP performance is provided by equipment manufacturers, and is typically limited to performance at a single operating speed for heating and cooling. Mini-split heat pumps use variable speed components that spin up and down to continuously meet the heating or cooling need, significantly improving a system's operating efficiency. Measuring that efficiency in a laboratory is challenging and required new approaches to performance testing. NREL researchers worked with colleagues at Purdue University's Herrick Labs and Ecotope, Inc. to refine and apply this new approach to a suite of MSHP products. Researchers measured the performance of two MSHPs across a variety of operating conditions, which allowed, for the first time, development of accurate building simulation MSHP models. In the laboratory tests, researchers found that both MSHPs achieved manufacturer-reported performance at rating conditions. However, at other temperature and humidity conditions, the heat pumps capacity ranged from 40% above to 54% below the manufacturer-reported values. Knowing how performance varies is critical in order to reasonably estimate annual energy consumption of a MSHP, and to compare MSHPs to other heating and cooling options. Mini-split heat pump efficiency (COP) was seen to significantly exceed rated efficiency at low compressor speeds-a very important effect.

Not Available

2012-06-01T23:59:59.000Z

339

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

E-Print Network [OSTI]

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

Sandwell, David T.

340

Thermoeconomic Analysis of a Solar Heat-Pump System  

E-Print Network [OSTI]

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

Gao, Y.; Wang, S.

2006-01-01T23:59:59.000Z

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.


341

Apparatus for microwave heat treatment of manufactured components  

DOE Patents [OSTI]

An apparatus for heat treating manufactured components using microwave energy and microwave susceptor material. Heat treating medium such as eutectic salts may be employed. A fluidized bed introduces process gases which may include carburizing or nitriding gases. The process may be operated in a batch mode or continuous process mode. A microwave heating probe may be used to restart a frozen eutectic salt bath.

Babcock & Wilcox Technical Services Y-12, LLC (Oak Ridge, TN)

2008-04-15T23:59:59.000Z

342

Methods for microwave heat treatment of manufactured components  

DOE Patents [OSTI]

An apparatus for heat treating manufactured components using microwave energy and microwave susceptor material. Heat treating medium such as eutectic salts may be employed. A fluidized bed introduces process gases which may include carburizing or nitriding gases. The process may be operated in a batch mode or continuous process mode. A microwave heating probe may be used to restart a frozen eutectic salt bath.

Ripley, Edward B. (Knoxville, TN)

2010-08-03T23:59:59.000Z

343

Transcontinental Rates  

E-Print Network [OSTI]

the Pacif ic Mail was left to continue its subsidized co - etition for through traffic. 3 It was in the year 1883 also that the North rn Pao! fio was opened for traffic to the Pacifio Northwest,and in the following year by the comp~tion of the Oregon B... 184. The N. P. owns and operates a line of railway from Ash land, Wis. to Portland, Oregon and Wallula, Wash. a distanc e of 2 , 137 miles. Its principal eastern termini are st. Pau1, Minneapolis and Duluth in Minnesota, and its 'rincipal wes~ ern...

Danskin, Floyd Brown

1913-01-01T23:59:59.000Z

344

Heat Pump for High School Heat Recovery  

E-Print Network [OSTI]

The heat pump system used for recycling and reusing waste heat in s high school bathroom was minutely analyzed in its coefficient of performance, onetime utilization ratio of energy, economic property and so on. The results showed that this system...

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

2006-01-01T23:59:59.000Z

345

AMBIPOLAR DIFFUSION HEATING IN TURBULENT SYSTEMS  

SciTech Connect (OSTI)

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

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

2012-11-20T23:59:59.000Z

346

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

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

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

347

Project Profile: Heat Transfer and Latent Heat Storage in Inorganic...  

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

Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for CSP Plants Project Profile: Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for CSP Plants...

348

Pagosa Springs District Heating District Heating Low Temperature...  

Open Energy Info (EERE)

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

349

Kethcum District Heating District Heating Low Temperature Geothermal...  

Open Energy Info (EERE)

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

350

Midland District Heating District Heating Low Temperature Geothermal...  

Open Energy Info (EERE)

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

351

San Bernardino District Heating District Heating Low Temperature...  

Open Energy Info (EERE)

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

352

Philip District Heating District Heating Low Temperature Geothermal...  

Open Energy Info (EERE)

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

353

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

E-Print Network [OSTI]

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

Ng, Chung-Sang

354

A Megawatt-level 28z GHz Heating System For The National Spherical Torus Experiment Upgrade  

SciTech Connect (OSTI)

The National Spherical Torus Experiment Upgrade (NSTX-U) will operate at axial toroidal fields of < 1 T and plasma currents, Ip < 2 MA. The development of non-inductive (NI) plasmas is a major long-term research goal for NSTX-U. Time dependent numerical simulations of 28 GHz electron cyclotron (EC) heating of low density NI start-up plasmas generated by Coaxial Helicity Injection (CHI) in NSTX-U predict a significant and rapid increase of the central electron temperature (Te(0)) before the plasma becomes overdense. The increased Te(0) will significantly reduce the Ip decay rate of CHI plasmas, allowing the coupling of fast wave heating and neutral beam injection. A megawatt-level, 28 GHz electron heating system is planned for heating NI start-up plasmas in NSTX-U. In addition to EC heating of CHI start-up discharges, this system will be used for electron Bernstein wave (EBW) plasma start-up, and eventually for EBW heating and current drive during the Ip flattop.

Taylor, Gary [PPPL

2014-04-01T23:59:59.000Z

355

Absorption heat pump system  

DOE Patents [OSTI]

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

Grossman, G.

1982-06-16T23:59:59.000Z

356

Locating Heat Recovery Opportunities  

E-Print Network [OSTI]

Basic concepts of heat recovery are defined as they apply to the industrial community. Methods for locating, ranking, and developing heat recovery opportunities are presented and explained. The needs for useful heat 'sinks' are emphasized as equal...

Waterland, A. F.

1981-01-01T23:59:59.000Z

357

Absorption heat pump system  

DOE Patents [OSTI]

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

Grossman, Gershon (Oak Ridge, TN)

1984-01-01T23:59:59.000Z

358

Rate schedule  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared at 278, 298, andEpidermal Growth Factor. |INCIDENCET3PACI-T3Rate

359

Modulating furnace and zoned-heating system development. Final report, July 1987-December 1989  

SciTech Connect (OSTI)

The report describes an experimental modulating furnace and a zoned warm air heating system for use in residences. The system was installed and tested at the National Association of Home Builders' (NAHB) SMART HOUSE in Bowie, Maryland. The key features of this system include: (1) continuous modulation of firing rate and supply air over a wide range, (2) closed-loop control to maintain a desired supply air flow under varying system resistances, (3) continuous modulation of combustion air to maintain efficiency, (4) a proportional-integral control algorithm operating on measured temperatures and set points in each zone to set the furnace firing rate, (5) low-cost on/off dampers to direct air flow to those zones calling for heat, and (6) a single microprocessor-based controller that integrates all aspects of the system.

Feldman, S.J.

1991-01-01T23:59:59.000Z

360

Woven heat exchanger  

DOE Patents [OSTI]

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

Piscitella, R.R.

1984-07-16T23:59:59.000Z

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

THERMOCHEMICAL HEAT STORAGE FOR CONCENTRATED SOLAR POWER  

SciTech Connect (OSTI)

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

PROJECT STAFF

2011-10-31T23:59:59.000Z

362

A performance data network for solar process heat systems  

SciTech Connect (OSTI)

A solar process heat (SPH) data network has been developed to access remote-site performance data from operational solar heat systems. Each SPH system in the data network is outfitted with monitoring equipment and a datalogger. The datalogger is accessed via modem from the data network computer at the National Renewable Energy Laboratory (NREL). The dataloggers collect both ten-minute and hourly data and download it to the data network every 24-hours for archiving, processing, and plotting. The system data collected includes energy delivered (fluid temperatures and flow rates) and site meteorological conditions, such as solar insolation and ambient temperature. The SPH performance data network was created for collecting performance data from SPH systems that are serving in industrial applications or from systems using technologies that show promise for industrial applications. The network will be used to identify areas of SPH technology needing further development, to correlate computer models with actual performance, and to improve the credibility of SPH technology. The SPH data network also provides a centralized bank of user-friendly performance data that will give prospective SPH users an indication of how actual systems perform. There are currently three systems being monitored and archived under the SPH data network: two are parabolic trough systems and the third is a flat-plate system. The two trough systems both heat water for prisons; the hot water is used for personal hygiene, kitchen operations, and laundry. The flat plate system heats water for meat processing at a slaughter house. We plan to connect another parabolic trough system to the network during the first months of 1996. We continue to look for good examples of systems using other types of collector technologies and systems serving new applications (such as absorption chilling) to include in the SPH performance data network.

Barker, G.; Hale, M.J.

1996-03-01T23:59:59.000Z

363

Intergalactic dust and its photoelectric heating  

E-Print Network [OSTI]

We have examined the dust photoelectric heating in the intergalactic medium (IGM). The heating rate in a typical radiation field of the IGM is represented by $\\Gamma_{\\rm pe} = 1.2\\times10^{-34}$ erg s$^{-1}$ cm$^{-3}$ $({\\cal D}/10^{-4})(n_{\\rm H}/10^{-5} {\\rm cm^{-3}})^{4/3} (J_{\\rm L}/10^{-21} {\\rm erg s^{-1} cm^{-2} Hz^{-1} sr^{-1}})^{2/3} (T/10^4 {\\rm K})^{-1/6}$, where ${\\cal D}$ is the dust-to-gas mass ratio, $n_{\\rm H}$ is the hydrogen number density, $J_{\\rm L}$ is the mean intensity at the hydrogen Lyman limit of the background radiation, and $T$ is the gas temperature, if we assume the new X-ray photoelectric yield model by Weingartner et al. (2006) and the dust size distribution in the Milky Way by Mathis, Rumpl, & Nordsieck (1977). This heating rate dominates the HI and HeII photoionization heating rates when the hydrogen number density is less than $\\sim10^{-6}$ cm$^{-3}$ if ${\\cal D}=10^{-4}$ which is 1% of that in the Milky Way, although the heating rate is a factor of 2--4 smaller than that with the old yield model by Weingartner & Draine (2001). The grain size distribution is very important. If only large ($\\ge0.1$ $\\mu$m) grains exist in the IGM, the heating rate is reduced by a factor of $\\simeq5$. Since the dust heating is more efficient in a lower density medium relative to the photoionization heating, it may cause an inverted temperature--density relation in the low density IGM suggested by Bolton et al. (2008). Finally, we have found that the dust heating is not very important in the mean IGM before the cosmic reionization.

Akio K. Inoue; Hideyuki Kamaya

2008-10-31T23:59:59.000Z

364

Heat flux solarimeter  

SciTech Connect (OSTI)

The solarimeter presented in this work is easy to assemble. It is calibrated and its performance is validated by means of Hottel's method. Finally, the curves obtained with this solarimeter are compared to the ones obtained with a commercial solarimeter. This device is based on the evaluation of the heat flow in a metal rod. In consequence, measurements are not affected by ambient temperature variations. On the other hand, there is a linear relationship between the temperatures measured at the rod ends and the incident radiation, as can be concluded both from the theory of its operation and the calibration lines obtained. The results obtained from the global irradiance measurements in the area of Los Polvorines (Buenos Aires Province), together with a preliminary evaluation of the solarimeter's response time, are presented in this work. (author)

Sartarelli, A.; Vera, S.; Cyrulies, E. [Instituto de Desarrollo Humano, Univ. Nac. de Gral. Sarmiento (IDH, UNGS), Los Polvorines (Argentina); Echarri, R. [Instituto de Desarrollo Humano, Univ. Nac. de Gral. Sarmiento (IDH, UNGS), Los Polvorines (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Samson, I. [INTEC (Instituto Tecnologico Santo Domingo), Santo Domingo (Dominican Republic)

2010-12-15T23:59:59.000Z

365

Total Space Heat-  

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

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

366

Total Space Heat-  

Gasoline and Diesel Fuel Update (EIA)

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

367

Towards Intelligent District Heating.  

E-Print Network [OSTI]

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

Johansson, Christian

2010-01-01T23:59:59.000Z

368

Winter Heating Fuels Update  

Gasoline and Diesel Fuel Update (EIA)

Heating Fuels Update For: Congressional Briefings October 20, 2014 | Washington, DC By U.S. Energy Information Administration Winter Heating Fuels Update October 20, 2014 |...

369

Confortable Performance: Retro-Commissioning Building Operations  

E-Print Network [OSTI]

troubleshooting ? New controls strategies ? Equipment schedule optimization ? Comfort improvements 7 ESL-IC-13-10-07 Proceedings of the 13th International Conference for Enhanced Building Operations, Montreal, Quebec, October 8-11, 2013 Tools ? Actuator... Operations, Montreal, Quebec, October 8-11, 2013 Example 1 ? Problem ? Monday morning ?too cold? complaints ? Solution ? Heating system start-up on Sunday at 2:00pm ? RCx Investigation ? Tenant MAU running 24x7 with no heat (space temperature...

Botan, L.

2013-01-01T23:59:59.000Z

370

Thermophoretic interaction of heat releasing particles Yu. Dolinskya)  

E-Print Network [OSTI]

Thermophoretic interaction of heat releasing particles Yu. Dolinskya) and T. Elperinb) Department investigates thermophoretic force acting at heat releasing absorbing particles near the interface between two of the thermophoretic force is proportional to the rate of heat release absorption by the particle, and its direction

Elperin, Tov

371

Pressurized reactor system and a method of operating the same  

DOE Patents [OSTI]

A method and apparatus are provided for operating a pressurized reactor system in order to precisely control the temperature within a pressure vessel in order to minimize condensation of corrosive materials from gases on the surfaces of the pressure vessel or contained circulating fluidized bed reactor, and to prevent the temperature of the components from reaching a detrimentally high level, while at the same time allowing quick heating of the pressure vessel interior volume during start-up. Superatmospheric pressure gas is introduced from the first conduit into the fluidized bed reactor and heat derived reactions such as combustion and gassification are maintained in the reactor. Gas is exhausted from the reactor and pressure vessel through a second conduit. Gas is circulated from one part of the inside volume to another to control the temperature of the inside volume, such as by passing the gas through an exterior conduit which has a heat exchanger, control valve, blower and compressor associated therewith, or by causing natural convection flow of circulating gas within one or more generally vertically extending gas passages entirely within the pressure vessel (and containing heat exchangers, flow rate control valves, or the like therein). Preferably, inert gas is provided as a circulating gas, and the inert gas may also be used in emergency shut-down situations. In emergency shut-down reaction gas being supplied to the reactor is cut off, while inert gas from the interior gas volume of the pressure vessel is introduced into the reactor.

Isaksson, Juhani M. (Karhula, FI)

1996-01-01T23:59:59.000Z

372

Pressurized reactor system and a method of operating the same  

DOE Patents [OSTI]

A method and apparatus are provided for operating a pressurized reactor system in order to precisely control the temperature within a pressure vessel in order to minimize condensation of corrosive materials from gases on the surfaces of the pressure vessel or contained circulating fluidized bed reactor, and to prevent the temperature of the components from reaching a detrimentally high level, while at the same time allowing quick heating of the pressure vessel interior volume during start-up. Super-atmospheric pressure gas is introduced from the first conduit into the fluidized bed reactor and heat derived reactions such as combustion and gasification are maintained in the reactor. Gas is exhausted from the reactor and pressure vessel through a second conduit. Gas is circulated from one part of the inside volume to another to control the temperature of the inside volume, such as by passing the gas through an exterior conduit which has a heat exchanger, control valve, blower and compressor associated therewith, or by causing natural convection flow of circulating gas within one or more generally vertically extending gas passages entirely within the pressure vessel (and containing heat exchangers, flow rate control valves, or the like therein). Preferably, inert gas is provided as a circulating gas, and the inert gas may also be used in emergency shut-down situations. In emergency shut-down reaction gas being supplied to the reactor is cut off, while inert gas from the interior gas volume of the pressure vessel is introduced into the reactor. 2 figs.

Isaksson, J.M.

1996-06-18T23:59:59.000Z

373

The smallest possible heat engines  

E-Print Network [OSTI]

We construct the smallest possible self contained heat engines; one composed of only two qubits, the other of only a single qutrit. The engines are self-contained as they do not require external sources of work and/or control. They are able to produce work which is used to continuously lift a weight. Despite the dimension of the engine being small, it is still able to operate at the Carnot efficiency.

Noah Linden; Sandu Popescu; Paul Skrzypczyk

2010-10-28T23:59:59.000Z

374

OPERATIONS (OPS)  

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

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)...

375

Design operators  

E-Print Network [OSTI]

Design operators is a thesis that investigates the nature and characteristics of the design process by examining the interaction of computation with architectural design. The effects of the introduction of these media in ...

Dritsas, Stylianos, 1978-

2004-01-01T23:59:59.000Z

376

Operating Costs  

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

This chapter is focused on capital costs for conventional construction and environmental restoration and waste management projects and examines operating cost estimates to verify that all elements of the project have been considered and properly estimated.

1997-03-28T23:59:59.000Z

377

Experimental study of an air-source heat pump for simultaneous heating and cooling Part 1: Basic concepts and performance verification  

E-Print Network [OSTI]

manufacturer. The operation of the high pressure control system, the transitions between heating, cooling, heating and cooling energies using the same electric energy input at the compressor. Chua et al. [31 Experimental study of an air-source heat pump for simultaneous heating and cooling ­ Part 1

Boyer, Edmond

378

Industrial Heat Pumps Using Solid/Vapor Working Fluids  

E-Print Network [OSTI]

INDUSTRIAL HEAT PUMPS USING SOLID/VAPOR WORKING FLUIDS Uwe Rockenfeller, Desert Research Institute, Boulder City, Nevada ABSTRACT Industrial heat pumps have the potential to reduce the operating costs of chemical and heat treating processes... with vapor re-compression recovery systems. The state-of-the-art heat pump equipment employing liquid/vapor working fluids fulfills the requirements only in some applications. The employment of solid/vapor complex compounds leads to 'nore cost effective...

Rockenfeller, U.

379

COSMIC RAY HEATING OF THE WARM IONIZED MEDIUM  

SciTech Connect (OSTI)

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

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

2013-04-10T23:59:59.000Z

380

Fragmentation of suddenly heated liquids  

SciTech Connect (OSTI)

Fragmentation of free liquids in Inertial Confinement Fusion reactors could determine the upper bound on reactor pulse rate. The x-ray ablated materials must cool and recondense to allow driver beam propagation. The increased surface area caused by fragmentation will enhance the cooling and condensation rates. Relaxation from the suddenly heated state will move a liquid into the negative pressure region under the liquid-vapor P-V dome. The lithium equation of state was used to demonstrate that neutron-induced vaporization uses only a minor fraction of the added heat, much less than would be required to drive the expansion. A 77% expansion of the lithium is required before the rapid vaporization process of spinodal decomposition could begin, and nucleation and growth are too slow to contribute to the expansion.

Blink, J.A.

1985-03-01T23:59:59.000Z

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.


381

Rotary magnetic heat pump  

DOE Patents [OSTI]

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

Kirol, L.D.

1987-02-11T23:59:59.000Z

382

Mass and Heat Recovery  

E-Print Network [OSTI]

In the last few years heat recovery was under spot and in air conditioning fields usually we use heat recovery by different types of heat exchangers. The heat exchanging between the exhaust air from the building with the fresh air to the building...

Hindawai, S. M.

2010-01-01T23:59:59.000Z

383

Direct fired heat exchanger  

SciTech Connect (OSTI)

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

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

1986-01-01T23:59:59.000Z

384

Rotary magnetic heat pump  

DOE Patents [OSTI]

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

Kirol, Lance D. (Shelly, ID)

1988-01-01T23:59:59.000Z

385

Operators eye closer service relationships  

SciTech Connect (OSTI)

The use of integrated drilling services and alliance-type contracts has become economical and more practicable for many operators and service companies world-wide. The alliance-type contract provides a better balance of risks and rewards shared equally among all operator and contractor parties than many standard day rate and turnkey contracts. The general trend toward longer term contracts with fewer supply companies has helped numerous operators remain competitive. The paper discusses the trend toward increased partnerships and fewer suppliers.

Deffarges, E.H.; Ellis, P.A. (Booz Allen Hamilton Inc., Paris (France)); McArthur, N.C. (Booz Allen Hamilton Inc., Wassenaar (Netherlands))

1994-09-19T23:59:59.000Z

386

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

E-Print Network [OSTI]

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

Kihm, IconKenneth David

387

Thulium-170 heat source  

DOE Patents [OSTI]

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

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

1992-01-01T23:59:59.000Z

388

Cooling and Clusters: When Is Heating Needed?  

E-Print Network [OSTI]

There are (at least) two unsolved problems concerning the current state of the thermal gas in clusters of galaxies. The first is identifying the source of the heating which offsets cooling in the centers of clusters with short cooling times (the ``cooling flow'' problem). The second is understanding the mechanism which boosts the entropy in cluster and group gas. Since both of these problems involve an unknown source of heating it is tempting to identify them with the same process, particular since AGN heating is observed to be operating at some level in a sample of well-observed ``cooling flow'' clusters. Here we show, using numerical simulations of cluster formation, that much of the gas ending up in clusters cools at high redshift and so the heating is also needed at high-redshift, well before the cluster forms. This indicates that the same process operating to solve the cooling flow problem may not also resolve the cluster entropy problem.

Greg L. Bryan; G. Mark Voit

2005-02-22T23:59:59.000Z

389

An Experimental Study of Upward and Downward Flow of Supercritical Carbon Dioxide in a Straight Pipe Heat Exchanger with Constant Wall Heat Flux  

E-Print Network [OSTI]

An experimental analysis was conducted on a single circular tube heat exchanger using supercritical carbon dioxide as the working fluid. The heat exchanger was operated in two different orientations: vertically upward and downward. The experimental...

Umrigar, Eric Dara

2014-05-01T23:59:59.000Z

390

Thermoelectric heat exchange element  

DOE Patents [OSTI]

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

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

2007-08-14T23:59:59.000Z

391

Heat Integrate Heat Engines in Process Plants  

E-Print Network [OSTI]

of forcing a good fit between a heat engine and process T', H profiles extends the ideas of appropriate and inappropriate placement to give bet ter overall integration schemes [7] . The new 'and powerful representations of the thermodynamics of a process... HEAT INTEGRATE HEAT ENGINES IN PROCESS PLANTS E. Hindmarsh, D. Boland and D.W. Townsend TENSA Technology, Houston, Texas Shorter Version Appeared in Chemical Engineering Copyright McGraw Hill, 1985 ABSTRACT This paper presents a novel method...

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

392

Waste Heat Recovery Power Generation with WOWGen  

E-Print Network [OSTI]

Waste Heat Recovery Power Generation with WOWGen? Business Overview 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...

Romero, M.

393

Transparent heat-spreader for optoelectronic applications  

DOE Patents [OSTI]

An optoelectronic cooling system is equally applicable to an LED collimator or a photovoltaic solar concentrator. A transparent fluid conveys heat from the optoelectronic chip to a hollow cover over the system aperture. The cooling system can keep a solar concentrator chip at the same temperature as found for a one-sun flat-plate solar cell. Natural convection or forced circulation can operate to convey heat from the chip to the cover.

Minano, Juan Carlos; Benitez, Pablo

2014-11-04T23:59:59.000Z

394

Heat Exchanger Technologies for Distillation Columns  

E-Print Network [OSTI]

each type of exchanger in turn. Heat exchanger size is minimised if the temperature driving force is maximised. The design should therefore seek to minimise the temperature changes during phase change. So, streams that are being condensed are kept... Reboiler not always possible (e.g. one part of a unit may be running at reduced load). Result: installed steam driven unit required to ensure integrity or heat recovery not used. Low temperature driving force Operation at low temperature driving force...

Polley, G. T.

395

Investigation of the Noncondensable Effect and the Operational Modes of the Passive Condenser System  

SciTech Connect (OSTI)

An experimental study is performed to investigate the effect of noncondensable gas in a passive condenser system. A vertical condenser tube is submerged in a water pool where the heat transferred from the condenser tube is removed through boiling. Data are obtained for three operational modes of the passive condenser. Degradation of the condensation with noncondensable gas is investigated. The condensation heat transfer rate is enhanced by increasing the inlet steam flow rate and the system pressure. For the condenser submerged in a saturated water pool, strong primary pressure dependency is observed. A boundary layer-based condensation model and a simple condensation model with the interfacial friction factor correlation are developed. The model predictions are compared with the pure steam data, and the agreement is satisfactory.

Oh, Seungmin; Revankar, Shripad T. [Purdue University (United States)

2005-10-15T23:59:59.000Z

396

TECHNOLOGIES TO ENHANCE THE OPERATION OF EXISTING NATURAL GAS COMPRESSION INFRASTRUCTURE  

SciTech Connect (OSTI)

This project has documented and demonstrated the feasibility of technologies and operational choices for companies who operate the large installed fleet of integral engine compressors in pipeline service. Continued operations of this fleet is required to meet the projected growth of the U.S. gas market. Applying project results will meet the goals of the DOE-NETL Natural Gas Infrastructure program to enhance integrity, extend life, improve efficiency, and increase capacity, while managing NOx emissions. These benefits will translate into lower cost, more reliable gas transmission, and options for increasing deliverability from the existing infrastructure on high demand days. The power cylinders on large bore slow-speed integral engine/compressors do not in general combust equally. Variations in cylinder pressure between power cylinders occur cycle-to-cycle. These variations affect both individual cylinder performance and unit average performance. The magnitude of the variations in power cylinder combustion is dependent on a variety of parameters, including air/fuel ratio. Large variations in cylinder performance and peak firing pressure can lead to detonation and misfires, both of which can be damaging to the unit. Reducing the variation in combustion pressure, and moving the high and low performing cylinders closer to the mean is the goal of engine balancing. The benefit of improving the state of the engine ''balance'' is a small reduction in heat rate and a significant reduction in both crankshaft strain and emissions. A new method invented during the course of this project is combustion pressure ratio (CPR) balancing. This method is more effective than current methods because it naturally accounts for differences in compression pressure, which results from cylinder-to-cylinder differences in the amount of air flowing through the inlet ports and trapped at port closure. It also helps avoid compensation for low compression pressure by the addition of excess fuel to achieve equalizing peak firing pressure, even if some of the compression pressure differences are attributed to differences in cylinder and piston geometry, clearance, and kinematics. The combination of high-pressure fuel injection and turbocharging should produce better mixing of fuel and air in lean mixtures. Test results documented modest improvements in heat rate and efficiency and significant improvements in emissions. The feasibility of a closed-loop control of waste-gate setting, which will maintain an equivalence ratio set point, has been demonstrated. This capability allows more direct tuning to enhance combustion stability, heat rate, or emissions. The project has documented the strong dependence of heat rate on load. The feasibility of directly measuring power and torque using the GMRC Rod Load Monitor (RLM) has been demonstrated. This capability helps to optimize heat rate while avoiding overload. The crankshaft Strain Data Capture Module (SDCM) has shown the sensitivity to changes in operating conditions and how they influence crankshaft bending strain. The results indicate that: balancing reduces the frequency of high-strain excursions, advanced timing directly increases crankshaft dynamic strain, reduced speed directly reduces strain, and high-pressure fuel injection reduces crankshaft strain slightly. The project demonstrated that when the timing is advanced, the heat rate is reduced, and when the timing is retarded, the heat rate is increased. One reason why timing is not advanced as much as it might be is the potential for detonation on hot days. A low-cost knock detector was demonstrated that allowed active control to use timing to allow the heat rate benefit to be realized safely. High flow resistance losses in the pulsation control systems installed on some compressors have been shown to hurt efficiency of both compressor and engine/compressor system. Improved pulsation control systems have the potential to recover almost 10% of available engine power. Integrity enhancements and reduced component failure probability will enhance aggregate

Anthony J. Smalley; Ralph E. Harris; Gary D. Bourn; Ford A. Phillips; Danny M. Deffenbaugh

2006-05-31T23:59:59.000Z

397

Fast repetition rate (FRR) flasher  

DOE Patents [OSTI]

A fast repetition rate (FRR) flasher is described suitable for high flash photolysis including kinetic chemical and biological analysis. The flasher includes a power supply, a discharge capacitor operably connected to be charged by the power supply, and a flash lamp for producing a series of flashes in response to discharge of the discharge capacitor. A triggering circuit operably connected to the flash lamp initially ionizes the flash lamp. A current switch is operably connected between the flash lamp and the discharge capacitor. The current switch has at least one insulated gate bipolar transistor for switching current that is operable to initiate a controllable discharge of the discharge capacitor through the flash lamp. Control means connected to the current switch for controlling the rate of discharge of the discharge capacitor thereby to effectively keep the flash lamp in an ionized state between successive discharges of the discharge capacitor. Advantageously, the control means is operable to discharge the discharge capacitor at a rate greater than 10,000 Hz and even up to a rate greater than about 250,000 Hz. 14 figs.

Kolber, Z.; Falkowski, P.

1997-02-11T23:59:59.000Z

398

Electron Cyclotron Heating in RFP plasmas  

SciTech Connect (OSTI)

Reversed field pinches (RFP) plasmas are typically overdense ({omega}{sub pe}>{omega}{sub ce}) and thus not suitable for conventional electron cyclotron (EC) heating and current drive. In recent high plasma current discharges (I{sub p}>1.5 MA), however, the RFX-mod device was operated in underdense conditions ({omega}{sub pe}<{omega}{sub ce}) for the first time in an RFP. Thus, it is now possible to envisage heating the RFP plasma core by conventional EC at the 2nd harmonic, in the ordinary or extraordinary mode. We present a preliminary study of EC-heating feasibility in RFX-mod with the use of beam-tracing and full-wave codes. Although not competitive - as a heating system - with multi-MW Ohmic heating in an RFP, EC might be useful for perturbative transport studies, even at moderate power (hundreds of kW), and, more generally, for applications requiring localized power deposition.

Bilato, R.; Poli, E. [MPI fuer Plasmaphysik-Euratom Association Boltzmannstr. 2, D-85748 Garching (Germany); Volpe, F. [Department of Engineering Physics, University of Wisconsin, Madison, WI (United States); Koehn, A. [Institut fuer Plasmaforschung, Universitaet Stuttgart-Stuttgart (Germany); Cavazzana, R.; Paccagnella, R. [Consorzio RFX-Associazione EURATOM-ENEA sulla fusione-Padova (Italy); Farina, D. [IFP-CNR, EURATOM-ENEA-CNR Association-Milano (Italy)

2009-11-26T23:59:59.000Z

399

Thermoelectric recovery of waste heat -- Case studies  

SciTech Connect (OSTI)

The use of waste heat as an energy source for thermoelectric generation largely removes the constraint for the wide scale application of this technology imposed by its relatively low conversion efficiency (typically about 5%). Paradoxically, in some parasitic applications, a low conversion efficiency can be viewed as a distinct advantage. However, commercially available thermoelectric modules are designed primarily for refrigerating applications and are less reliable when operated at elevated temperatures. Consequently, a major factor which determines the economic competitiveness of thermoelectric recovery of waste heat is the cost per watt divided by the mean-time between module failures. In this paper is reported the development of a waste, warm water powered thermoelectric generator, one target in a NEDO sponsored project to economically recover waste heat. As an application of this technology case studies are considered in which thermoelectric generators are operated in both active and parasitic modes to generate electrical power for a central heating system. It is concluded that, in applications when the supply of heat essentially is free as with waste heat, thermoelectrics can compete economically with conventional methods of electrical power generation. Also, in this situation, and when the generating system is operated in a parasitic mode, conversion efficiency is not an important consideration.

Rowe, M.D.; Min, G.; Williams, S.G.K.; Aoune, A. [Cardiff School of Engineering (United Kingdom). Div. of Electronic Engineering; Matsuura, Kenji [Osaka Univ., Suita, Osaka (Japan). Dept. of Electrical Engineering; Kuznetsov, V.L. [Ioffe Physical-Technical Inst., St. Petersburg (Russian Federation); Fu, L.W. [Tsinghua Univ., Beijing (China). Microelectronics Inst.

1997-12-31T23:59:59.000Z

400

Recovery Act - Geothermal Technologies Program: Ground Source Heat Pumps Final Scientific/Technical Report  

SciTech Connect (OSTI)

A large centralized geothermal heat pump system was installed to provide ice making, space cooling, space heating, process water heating, and domestic hot water heating for an ice arena in Eagan Minnesota. This paper provides information related to the design and construction of the project. Additionally, operating conditions for 12 months after start-up are provided.

Nick Rosenberry, Harris Companies

2012-05-04T23:59:59.000Z

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.


401

Adding Environmental Gas Physics to the Semi-Analytic Method for Galaxy Formation: Gravitational Heating  

E-Print Network [OSTI]

We present results of an attempt to include more detailed gas physics motivated from hydrodynamical simulations within semi-analytic models (SAM) of galaxy formation, focusing on the role that environmental effects play. The main difference to previous SAMs is that we include 'gravitational' heating of the intra-cluster medium (ICM) by the net surplus of gravitational potential energy released from gas that has been stripped from infalling satellites. Gravitational heating appears to be an efficient heating source able to prevent cooling in environments corresponding to dark matter halos more massive than $\\sim 10^{13} $M$_{\\odot}$. The energy release by gravitational heating can match that by AGN-feedback in massive galaxies and can exceed it in the most massive ones. However, there is a fundamental difference in the way the two processes operate. Gravitational heating becomes important at late times, when the peak activity of AGNs is already over, and it is very mass dependent. This mass dependency and time behaviour gives the right trend to recover down-sizing in the star-formation rate of massive galaxies. Abridged...

S. Khochfar; J. P. Ostriker

2007-04-18T23:59:59.000Z

402

Control system for fluid heated steam generator  

DOE Patents [OSTI]

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

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

1984-05-29T23:59:59.000Z

403

Dynamics of heat transfer between nano systems  

E-Print Network [OSTI]

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

Svend-Age Biehs; Girish S. Agarwal

2012-10-18T23:59:59.000Z

404

Retrofitting Combined Space and Water Heating Systems: Laboratory Tests  

SciTech Connect (OSTI)

Better insulated and tighter homes can often use a single heating plant for both space and domestic water heating. These systems, called dual integrated appliances (DIA) or combination systems, can operate at high efficiency and eliminate combustion safety issues associated by using a condensing, sealed combustion heating plant. Funds were received to install 400 DIAs in Minnesota low-income homes. The NorthernSTAR DIA laboratory was created to identify proper system components, designs, operating parameters, and installation procedures to assure high efficiency of field installed systems. Tests verified that heating loads up to 57,000 Btu/hr can be achieved with acceptable return water temperatures and supply air temperatures.

Schoenbauer, B.; Bohac, D.; Huelman, P.; Olson, R.; Hewitt, M.

2012-10-01T23:59:59.000Z

405

Modern hot water district heating  

SciTech Connect (OSTI)

The history of district heating in Europe is drastically different from that in the United States. The development of district heating in northern and eastern Europe started in the early 1950s. Hot water rather than steam was used as the transport medium and the systems have proven to be more economical. Recently, the northern European concept has been introduced into two US cities - St. Paul and Willmar, Minnesota. The hot water project in St. Paul started construction and operation in the summer and fall of 1983, respectively. The entire first phase of the St. Paul project will take two summers to construct and will connect approximately 80 buildings for a total of 150 MW(t). The system spans the entire St. Paul business district and includes privately owned offices and retail buildings, city and county government buildings, hospitals, the state Capitol complex, and several industrial customers. The City of Willmar, Minnesota, replaced an old steam system with a modern hot water system in the summer of 1982. The first phase of the hot water system was constructed in the central business district. The system serves a peak thermal load of about 10 MW(t) and includes about 12,000 ft of network. The Willmar system completed the second stage of development in the fall of 1983. These two new systems demonstrate the benefits of the low-temperature hot water district heating technology. The systems are economical to build, have high reliability, and have low maintenance and operating cost.

Karnitz, M.A.; Barnes, M.H.; Kadrmas, C.; Nyman, H.O.

1984-06-01T23:59:59.000Z

406

Testing of Crystallization Temperature of a New Working Fluid for Absorption Heat Pump Systems  

SciTech Connect (OSTI)

Lithium bromide/water (LiBr/water) absorption systems are potential candidates for absorption heat pump water heating applications since they have been widely commercialized for cooling applications. One drawback to LiBr/water absorption water heater systems is that they are unable to operate at typical water heating temperatures due to solution crystallization hazards. Binary or ternary mixtures, serving as working fluids, were reported (Ally, 1988; Herold et al., 1991; Iyoki and Uemura, 1981; Yasuhide Nemoto et al., 2010; Zogg et al., 2005) to help improve the absorption performance or avoid crystallization of absorption heat pump systems. A recent development (De Lucas et al., 2007) investigated the use of a ternary mixture of aqueous mixture of lithium bromide and sodium formate (CHO2Na). The new working fluid composition maintains a ratio of LiBr/CHO2Na of 2 by weight. This new working fluid is a potential competitor to aqueous LiBr solution in absorption system due to higher water vapor absorption rates and lower generation temperature needed (De Lucas et al., 2004). There exists data on equilibrium performance and other physical properties of this new working fluid. However, there is no available data on crystallization behavior. Crystallization temperature is crucial for the design of absorption heat pump water heater in order to avoid crystallization hazards during operation. We have therefore conducted a systematic study to explore the crystallization temperature of LiBr/CHO2Na water solution and compared it against aqueous LiBr solutions. These results were then used to evaluate the feasibility of using the new working fluid in water heating applications showing limited potential.

Wang, Kai [ORNL] [ORNL; Kisari, Padmaja [ORNL] [ORNL; Abdelaziz, Omar [ORNL] [ORNL; Vineyard, Edward Allan [ORNL] [ORNL

2010-01-01T23:59:59.000Z

407

Operation Poorman  

SciTech Connect (OSTI)

The objectives of Operation Poorman were to design and build a portable seismic system and to set up and use this system in a cold-weather environment. The equipment design uses current technology to achieve a low-power, lightweight system that is configured into three modules. The system was deployed in Alaska during wintertime, and the results provide a basis for specifying a mission-ready seismic verification system.

Pruvost, N.; Tsitouras, J.

1981-03-18T23:59:59.000Z

408

Operations Videos  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recoveryLaboratorySpeeding access1 TechnicalOilOnlineandOperations

409

HEATING 7. 1 user's manual  

SciTech Connect (OSTI)

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

Childs, K.W.

1991-07-01T23:59:59.000Z

410

Surface-induced heating of cold polar molecules  

E-Print Network [OSTI]

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

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

2008-06-18T23:59:59.000Z

411

State Heating Oil & Propane Program. Final report 1997/98 heating season  

SciTech Connect (OSTI)

The following is a summary report of the New Hampshire Governor`s Office of Energy and Community Services (ECS) participation in the State Heating Oil and Propane Program (SHOPP) for the 1997/98 heating season. SHOPP is a cooperative effort, linking energy offices in East Coast and Midwest states, with the Department of Energy (DOE), Energy Information Administration (EIA) for the purpose of collecting retail price data for heating oil and propane. The program is funded by the participating state with a matching grant from DOE. SHOPP was initiated in response to congressional inquires into supply difficulties and price spikes of heating oil and propane associated with the winter of 1989/90. This is important to New Hampshire because heating oil controls over 55% of the residential heating market statewide. Propane controls 10% of the heating market statewide and is widely used for water heating and cooking in areas of the state where natural gas is not available. Lower installation cost, convenience, lower operating costs compared to electricity, and its perception as a clean heating fuel have all worked to increase the popularity of propane in New Hampshire and should continue to do so in the future. Any disruption in supply of these heating fuels to New Hampshire could cause prices to skyrocket and leave many residents in the cold.

Hunton, G.

1998-06-01T23:59:59.000Z

412

RADIATIVE HEATING OF THE SOLAR CORONA  

SciTech Connect (OSTI)

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

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

2011-10-20T23:59:59.000Z

413

Subsurface heaters with low sulfidation rates  

DOE Patents [OSTI]

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

John, Randy Carl; Vinegar, Harold J

2013-12-10T23:59:59.000Z

414

Consolidated Electric Cooperative- Heat Pump and Water Heating Rebates  

Broader source: Energy.gov [DOE]

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

415

Spectral Functions of Singular Operators  

E-Print Network [OSTI]

The asymptotic expansion of the heat-kernel for small values of its argument has been studied in many different cases and has been applied to 1-loop calculations in Quantum Field Theory. In this thesis we consider this asymptotic behavior for certain singular differential operators which can be related to quantum fields on manifolds with conical singularities. Our main result is that, due to the existence of this singularity and of infinitely many boundary conditions of physical relevance related to the admissible behavior of the fields on the singular point, the heat-kernel has an "unusual" asymptotic expansion. We describe examples where the heat-kernel admits an asymptotic expansion in powers of its argument whose exponents depend on "external" parameters. As far as we know, this kind of asymptotics had not been found and therefore its physical consequences are still unexplored.

Pablo Pisani

2014-10-28T23:59:59.000Z

416

Photovoltaic roof heat flux  

E-Print Network [OSTI]

designs (relatively) Photovoltaic Solar P a n e l AtmosphereCALIFORNIA, SAN DIEGO Photovoltaic Roof Heat Flux A ThesisABSTRACT OF T H E THESIS Photovoltaic Roof Heat Flux by

Samady, Mezhgan Frishta

2011-01-01T23:59:59.000Z

417

HEAT TRANSFER FLUIDS  

E-Print Network [OSTI]

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

Lenert, Andrej

2012-01-01T23:59:59.000Z

418

Variable frequency microwave heating apparatus  

DOE Patents [OSTI]

A variable frequency microwave heating apparatus (10) designed to allow modulation of the frequency of the microwaves introduced into a multi-mode microwave cavity (34) for testing or other selected applications. The variable frequency microwave heating apparatus (10) includes a microwave signal generator (12) and a high-power microwave amplifier (20) or a high-power microwave oscillator (14). A power supply (22) is provided for operation of the high-power microwave oscillator (14) or microwave amplifier (20). A directional coupler (24) is provided for detecting the direction and amplitude of signals incident upon and reflected from the microwave cavity (34). A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

Bible, Don W. (Clinton, TN); Lauf, Robert J. (Oak Ridge, TN); Johnson, Arvid C. (Lake in the Hills, IL); Thigpen, Larry T. (Angier, NC)

1999-01-01T23:59:59.000Z

419

Process Waste Heat Recovery in the Food Industry - A System Analysis  

E-Print Network [OSTI]

An analysis of an industrial waste heat recovery system concept is discussed. For example purposes, a food processing plant operating an ammonia refrigeration system for storage and blast freezing is considered. Heat is withdrawn from...

Lundberg, W. L.; Mutone, G. A.

1983-01-01T23:59:59.000Z

420

CHARACTERIZATION OF ELEVATED TEMPERATURE PROPERTIES OF HEAT EXCHANGER AND STEAM GENERATOR ALLOYS  

SciTech Connect (OSTI)

The Next Generation Nuclear Plant project is considering Alloy 800H and Alloy 617 for steam generator and intermediate heat exchangers. It is envisioned that a steam generator would operate with reactor outlet temperatures from 750 to 800 C, while an intermediate heat exchanger for primary to secondary helium would operate up to an outlet temperature of 950 C. Although both alloys are of interest due in part to their technical maturity, a number of specific properties require further characterization for design of nuclear components. Strain rate sensitivity of both alloys has been characterized and is found to be significant above 600 C. Both alloys also exhibit dynamic strain aging, characterized by serrated flow, over a wide range of temperatures and strain rates. High temperature tensile testing of Alloy 617 has been conducted over a range of temperatures. Dynamic strain aging is a concern for these materials since it is observed to result in reduced ductility for many solid solution alloys. Creep, fatigue, and creep-fatigue properties of Alloy 617 have been measured as well, with the goal of determining the influence of the temperature, strain rate and atmosphere on the creep fatigue life of Alloy 617. Elevated temperature properties and implications for codification of the alloys will be described.

J.K. Wright; L.J. Carroll; C.J. Cabet; T. Lillo; J.K. Benz; J.A. Simpson; A. Chapman; R.N. Wright

2012-10-01T23:59:59.000Z

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.


421

Abrasion resistant heat pipe  

DOE Patents [OSTI]

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

Ernst, Donald M. (Leola, PA)

1984-10-23T23:59:59.000Z

422

MA HEAT Loan Overview  

Broader source: Energy.gov [DOE]

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

423

Abrasion resistant heat pipe  

DOE Patents [OSTI]

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

Ernst, D.M.

1984-10-23T23:59:59.000Z

424

Solar heat receiver  

DOE Patents [OSTI]

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

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

1982-09-29T23:59:59.000Z

425

Examination of Liquid Fluoride Salt Heat Transfer  

SciTech Connect (OSTI)

The need for high efficiency power conversion and energy transport systems is increasing as world energy use continues to increase, petroleum supplies decrease, and global warming concerns become more prevalent. There are few heat transport fluids capable of operating above about 600oC that do not require operation at extremely high pressures. Liquid fluoride salts are an exception to that limitation. Fluoride salts have very high boiling points, can operate at high temperatures and low pressures and have very good heat transfer properties. They have been proposed as coolants for next generation fission reactor systems, as coolants for fusion reactor blankets, and as thermal storage media for solar power systems. In each case, these salts are used to either extract or deliver heat through heat exchange equipment, and in order to design this equipment, liquid salt heat transfer must be predicted. This paper discusses the heat transfer characteristics of liquid fluoride salts. Historically, heat transfer in fluoride salts has been assumed to be consistent with that of conventional fluids (air, water, etc.), and correlations used for predicting heat transfer performance of all fluoride salts have been the same or similar to those used for water conventional fluids an, water, etc). A review of existing liquid salt heat transfer data is presented, summarized, and evaluated on a consistent basis. Less than 10 experimental data sets have been found in the literature, with varying degrees of experimental detail and measured parameters provided. The data has been digitized and a limited database has been assembled and compared to existing heat transfer correlations. Results vary as well, with some data sets following traditional correlations; in others the comparisons are less conclusive. This is especially the case for less common salt/materials combinations, and suggests that additional heat transfer data may be needed when using specific salt eutectics in heat transfer equipment designs. All of the data discussed above were taken under forced convective conditions (both laminar and turbulent). Some recent data taken at ORNL under free convection conditions are also presented and results discussed. This data was taken using a simple crucible experiment with an instrumented nickel heater inserted in the salt to induce natural circulation within the crucible. The data was taken over a temperature range of 550oC to 650oC in FLiNaK salt. This data covers both laminar and turbulent natural convection conditions, and is compared to existing forms of natural circulation correlations.

Yoder Jr, Graydon L [ORNL] [ORNL

2014-01-01T23:59:59.000Z

426

Operations Information  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 The 2002 WholesaleEnergy'sRunning jobsOPERATING PLANOperations

427

Method and apparatus for obtaining enhanced production rate of thermal chemical reactions  

DOE Patents [OSTI]

Reactors and processes are disclosed that can utilize high heat fluxes to obtain fast, steady-state reaction rates. Porous catalysts used in conjunction with microchannel reactors to obtain high rates of heat transfer are also disclosed. Reactors and processes that utilize short contact times, high heat flux and low pressure drop are described. Improved methods of steam reforming are also provided.

Tonkovich, Anna Lee Y. (Pasco, WA); Wang, Yong (Richland, WA); Wegeng, Robert S. (Richland, WA); Gao, Yufei (Kennewick, WA)

2006-05-16T23:59:59.000Z

428

Method and apparatus for obtaining enhanced production rate of thermal chemical reactions  

DOE Patents [OSTI]

Reactors and processes are disclosed that can utilize high heat fluxes to obtain fast, steady-state reaction rates. Porous catalysts used in conjunction with microchannel reactors to obtain high rates of heat transfer are also disclosed. Reactors and processes that utilize short contact times, high heat flux and low pressure drop are described. Improved methods of steam reforming are also provided.

Tonkovich, Anna Lee; Wang, Yong; Wegeng, Robert S.; Gao, Yufei

2003-09-09T23:59:59.000Z

429

Ammoniated salt heat pump  

SciTech Connect (OSTI)

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

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

1981-01-01T23:59:59.000Z

430

Heat Transfer Guest Editorial  

E-Print Network [OSTI]

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

Kandlikar, Satish

431

Acoustic Heating Peter Ulmschneider  

E-Print Network [OSTI]

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

Ulmschneider, Peter

432

Liquid heat capacity lasers  

DOE Patents [OSTI]

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

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

2007-05-01T23:59:59.000Z

433

Pioneering Heat Pump Project  

Broader source: Energy.gov [DOE]

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

434

Heat transfer rates in fixed bed catalytic reactors  

E-Print Network [OSTI]

the flare was properly made. The vent line was made from one-half inch pipe and extended several feet through a laboratory window. Pipe was permissible here since no pressure existed in the line. Gas Purifiers The construction of a gas purifier is shown... ........................................................................ 118 LIST OF FIGURES Pap1. FLOW SYSTEM............................................................. ............... 28 2. GAS PURIFIER.............................................................................. 32 3. DIFFERENTIAL REACTOR...

Levelton, Bruce Harding

1951-01-01T23:59:59.000Z

435

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

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcal Documentation(AVIRIS) ProductsAirborne Visible/Infrared Imaging Spectrometer (AVIRIS) ARM

436

Status of the Broadband Heating Rate Profile (BBHRP) VAP  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systemsBiSiteNeutron Scattering4 ByWatchingState ofDr.

437

Sensitivity of Radiative Fluxes and Heating Rates to Cloud Microphysics  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systemsBi (2) SrEvaluating theDepartmentSensitivity of Radiative Fluxes and

438

A corrosive resistant heat exchanger  

DOE Patents [OSTI]

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

Richlen, S.L.

1987-08-10T23:59:59.000Z

439

Waste heat recovery: Textile industry. (Latest citations from World Textile Abstracts database). Published Search  

SciTech Connect (OSTI)

The bibliography contains citations concerning descriptions and evaluations of waste heat recovery operations used in the textile industry. Heat recovery and utilization from wastewater streams, flue gas, finishing processes, dyeing operations, and air jet systems are presented. The use of waste heat for space heating and process preheating is considered. (Contains a minimum of 162 citations and includes a subject term index and title list.)

Not Available

1993-08-01T23:59:59.000Z

440

2. Unit Operation Dynamic simulation Unit operation  

E-Print Network [OSTI]

specification . 2.2 Heat transfer equipment Air cooler, cooler/heater, heat exchanger, fired heater LNG multi flow heat exchanger . 2.3 Piping equipment Mixer, tee, pipe, gas pipe, valve, relief valve . 2.4 Rotating equipment Centrifugal compressor or expander, reciprocating compressor pump ,dynamic simulation

Hong, Deog Ki

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.


441

Ground-source Heat Pumps Applied to Commercial Buildings  

SciTech Connect (OSTI)

Ground-source heat pumps can provide an energy-efficient, cost-effective way to heat and cool commercial facilities. While ground-source heat pumps are well established in the residential sector, their application in larger, commercial-style, facilities is lagging, in part because of a lack of experience with the technology by those in decision-making positions. Through the use of a ground-coupling system, a conventional water-source heat pump design is transformed to a unique means of utilizing thermodynamic properties of earth and groundwater for efficient operation throughout the year in most climates. In essence, the ground (or groundwater) serves as a heat source during winter operation and a heat sink for summer cooling. Many varieties in design are available, so the technology can be adapted to almost any site. Ground-source heat pump systems can be used widely in commercial-building applications and, with proper installation, offer great potential for the commercial sector, where increased efficiency and reduced heating and cooling costs are important. Ground-source heat pump systems require less refrigerant than conventional air-source heat pumps or air-conditioning systems, with the exception of direct-expansion-type ground-source heat pump systems. This chapter provides information and procedures that an energy manager can use to evaluate most ground-source heat pump applications. Ground-source heat pump operation, system types, design variations, energy savings, and other benefits are explained. Guidelines are provided for appropriate application and installation. Two case studies are presented to give the reader a sense of the actual costs and energy savings. A list of manufacturers and references for further reading are included for prospective users who have specific or highly technical questions not fully addressed in this chapter. Sample case spreadsheets are provided in Appendix A. Additional appendixes provide other information on the ground-source heat pump technology.

Parker, Steven A.; Hadley, Donald L.

2009-07-14T23:59:59.000Z

442

Neutron behavior, reactor control, and reactor heat transfer. Volume four  

SciTech Connect (OSTI)

Volume four covers neutron behavior (neutron absorption, how big are nuclei, neutron slowing down, neutron losses, the self-sustaining reactor), reactor control (what is controlled in a reactor, controlling neutron population, is it easy to control a reactor, range of reactor control, what happens when the fuel burns up, controlling a PWR, controlling a BWR, inherent safety of reactors), and reactor heat transfer (heat generation in a nuclear reactor, how is heat removed from a reactor core, heat transfer rate, heat transfer properties of the reactor coolant).

Not Available

1986-01-01T23:59:59.000Z

443

Magnetars as cooling neutron stars with internal heating  

E-Print Network [OSTI]

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

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

2006-05-18T23:59:59.000Z

444

Phenylnaphthalene Derivatives as Heat Transfer Fluids for Concentrating Solar Power: Loop Experiments and Final Report  

SciTech Connect (OSTI)

ORNL and subcontractor Cool Energy completed an investigation of higher-temperature, organic thermal fluids for solar thermal applications. Although static thermal tests showed promising results for 1-phenylnaphthalene, loop testing at temperatures to 450 C showed that the material isomerized at a slow rate. In a loop with a temperature high enough to drive the isomerization, the higher melting point byproducts tended to condense onto cooler surfaces. So, as experienced in loop operation, eventually the internal channels of cooler components such as the waste heat rejection exchanger may become coated or clogged and loop performance will decrease. Thus, pure 1-phenylnaphthalene does not appear to be a fluid that would have a sufficiently long lifetime (years to decades) to be used in a loop at the increased temperatures of interest. Hence a decision was made not to test the ORNL fluid in the loop at Cool Energy Inc. Instead, Cool Energy tested and modeled power conversion from a moderate-temperature solar loop using coupled Stirling engines. Cool Energy analyzed data collected on third and fourth generation SolarHeart Stirling engines operating on a rooftop solar field with a lower temperature (Marlotherm) heat transfer fluid. The operating efficiencies of the Stirling engines were determined at multiple, typical solar conditions, based on data from actual cycle operation. Results highlighted the advantages of inherent thermal energy storage in the power conversion system.

McFarlane, Joanna [ORNL; Bell, Jason R [ORNL; Felde, David K [ORNL; Joseph III, Robert Anthony [ORNL; Qualls, A L [ORNL; Weaver, Samuel P [ORNL

2013-02-01T23:59:59.000Z

445

Potential for supplying solar thermal energy to industrial unit operations  

SciTech Connect (OSTI)

Previous studies have identified major industries deemed most appropriate for the near-term adoption of solar thermal technology to provide process heat; these studies have been based on surveys that followed standard industrial classifications. This paper presents an alternate, perhaps simpler analysis of this potential, considered in terms of the end-use of energy delivered to industrial unit operations. For example, materials, such as animal feed, can be air dried at much lower temperatures than are currently used. This situation is likely to continue while economic supplies of natural gas are readily available. However, restriction of these supplies could lead to the use of low-temperature processes, which are more easily integrated with solar thermal technology. The adoption of solar technology is also favored by other changes, such as the relative rates of increase of the costs of electricity and natural gas, and by energy conservation measures. Thus, the use of low-pressure steam to provide process heat could be replaced economically with high-temperature hot water systems, which are more compatible with solar technology. On the other hand, for certain operations such as high-temperature catalytic and distillation processes employed in petroleum refining, there is no ready alternative to presently employed fluid fuels.

May, E.K.

1980-04-01T23:59:59.000Z

446

Operation strategy for solid oxide fuel cell systems for small-scale stationary applications  

E-Print Network [OSTI]

or heat at the site where it is used. This concept reduces grid losses and focuses on demand rather than consumption by providing both heat and power on site without transmission losses. The high grade heat produced variation during the operation. The analysis will consider an average profile for heat and power demand

Berning, Torsten

447

Active microchannel heat exchanger  

DOE Patents [OSTI]

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

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

2001-01-01T23:59:59.000Z

448

Feasibility of a complex compound heat pump. Annual report, July 1986-June 1987  

SciTech Connect (OSTI)

This report describes the feasibility study of a double-effect gas-fired heat pump using ammoniated solid-vapor complex compounds as the working media. The cycle takes advantage of the coordinative characteristic of complex compound-ligand bonds resulting in large coordination spheres with only one degree of freedom. The cycle has high efficiency, no moving parts, and minimum electrical parasitic requirements. Fluid properties of candidate materials were measured with respect to vapor-pressure equilibria, coordination properties, and thermal stability. Preliminary reaction rate measurements were performed in adsorption and desorption processes. A computer model of double-effect cycle was developed in order to predict the operating performance of the candidate complex compound media. The computer model was used to determine preliminary heat balances and coefficients of performance, indicating COPc of about 1.0 and COPh of about 2.1 should be achievable.

Rockenfeller, U.

1987-07-01T23:59:59.000Z

449

Brayton Cycle Heat Pump for VOC Control  

E-Print Network [OSTI]

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

Kovach, J. L.

450

PERFORMANCE OF A STIRLING ENGINE POWERED HEAT ACTIVATED HEAT PUMP  

E-Print Network [OSTI]

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

Oak Ridge National Laboratory

451

Experimental Investigation of Forced Convection Heat Transfer of Nanofluids in a Microchannel using Temperature Nanosensors  

E-Print Network [OSTI]

for performing the experimental measurements. TFT arrays were designed (which included design of photomask layout), microfabricated, packaged and assembled for testing with the experimental apparatus. Heat removal rates from the heated surface to the different...

Yu, Jiwon 1982-

2012-12-03T23:59:59.000Z

452

Program listing for heat-pump seasonal-performance model (SPM). [CNHSPM  

SciTech Connect (OSTI)

The computer program CNHSPM is listed which predicts heat pump seasonal energy consumption (including defrost, cyclic degradation, and supplementary heat) using steady state rating point performance and binned weather data. (LEW)

Not Available

1982-06-30T23:59:59.000Z

453

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

E-Print Network [OSTI]

Cooling Heat and Power (CCHP) systems are being installed atand heating loads. These CCHP systems can also act as backupgenerators. In all cases the CCHP systems are rated at a

Norwood, Zack

2010-01-01T23:59:59.000Z

454

Systematic method for the condition assessment of central heating plants in Air Force Logistics Command. Master's thesis  

SciTech Connect (OSTI)

Air Force Logistics Command (AFLC), facing decreasing funds and aging utility systems, needed a method to objectively rate its central heating plants. Such a rating system would be used to compare heating plants throughout the command to identify potential problem areas and prioritize major repair projects. This thesis used a Delphi questionnaire to gather opinions from heating plant experts in order to identify and prioritize components considered most critical to overall plant operation. In addition, the experts suggested measurements which could be used to evaluate component conditions. By combining expert opinions and reading from technical literature, component model rating schemes were developed for AFLC's steam and high temperature hot water plants. Based on measurements and observations of critical components in the plant, a score between 0 and 100 is assigned to each component (for example, condensate piping, deaerator, etc.), each plant subsystem (distribution system, water treatment system, etc.), and to the plant as a whole. These component model rating schemes and the resultant overall condition index scores will enable AFLC to focus their management attention and allocate needed resources to the plants in greatest need of repair.

Starmack, G.J.

1990-09-01T23:59:59.000Z

455

Industrial heat pumps: types and costs  

SciTech Connect (OSTI)

Many potentially beneficial applications for industrial heat pumps are not being pursued because of confusion regarding both energy savings and economics. Part of this confusion stems from the variety of heat pumps available and the fact that the measure of merit, the coefficient of performance (COP), is commonly defined in at least three different ways. In an attempt to circumvent this problem, a simple categorization was developed based on the commonly accepted COP definitions. Using this categorization, the cost of recovering waste energy with heat pumps was examined. Examples were evaluated in which the cost of energy delivered was calculated based on estimates of capital cost, operating costs, and maintenance costs. Heat pumps from the various categories were then compared on the basis of economics.

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

1985-03-01T23:59:59.000Z

456

Industrial heat pumps - types and costs  

SciTech Connect (OSTI)

Many potentially beneficial applications for industrial heat pumps are not being pursued because of confusion regarding both energy savings and economics. Part of this confusion stems from the variety of heat pumps available and the fact that the measure of merit, the coefficient of performance (COP) is commonly defined in at least three different ways. In an attempt to circumvent this problem, a simple categorization was developed based on the commonly accepted COP definitions. Using this categorization, the cost of recovering waste energy with heat pumps was examined. Examples were evaluated in which the cost of energy delivered was calculated based on estimates of capital cost, operating costs, and maintenance costs. Heat pumps from the various categories were then compared on the basis of economics. 6 refs., 7 figs.

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

1985-01-01T23:59:59.000Z

457

Nuclear heated and powered metal excimer laser  

SciTech Connect (OSTI)

A laser uses heat and thermionic electrical output from a nuclear reactor in which heat generated by the reactor is utilized to vaporize metal lasants. Voltage output from a thermionic converter is used to create an electric discharge in the metal vapors. In one embodiment the laser vapors are excited by a discharge only. The second embodiment utilizes fission coatings on the inside of heat pipes, in which fission fragment excitation and ionization is employed in addition to a discharge. Both embodiments provide efficient laser systems that are capable of many years of operation without servicing. Metal excimers are the most efficient electronic transition lasers known with output in the visible wavelengths. Use of metal excimers, in addition to their efficiency and wavelengths, allows utilization of reactor waste heat which plagues many nuclear pumped laser concepts.

Womack, D.R.

1982-02-11T23:59:59.000Z

458

Advanced Chemical Heat Pumps Using Liquid-Vapor Reactions  

E-Print Network [OSTI]

ically feasible systems have significant potential advantage over conventional tech nology. An electric drive reactive heat pump can use smaller heat exchangers and compressor than a vapor-compression machine, and have more flexible operating... are discussed, and performance is bounded. A discussion on liquid-vapor equilibria is included as introduction to the systems I- considered. The electric drive heat pump and TA are promising systems; the TA has potential for higher COP than absorption...

Kirol, L.

459

Membrane heat pipe development for space radiator applications  

SciTech Connect (OSTI)

A self-deploying membrane heat pipe (SMHP) is being designed and fabricated to operate in an in-cabin experiment aboard a STS flight. The heat pipe comprises a mylar membrane with a woven fabric arterial wick and R-11 as the working fluid. Preliminary results indicate that this SMHP design will successfully expand and retract in response to an applied heat load; the retraction force is provided by a constant force spring.

Woloshun, K.; Merrigan, M.

1986-01-01T23:59:59.000Z

460

Commercial high efficiency dehumidification systems using heat pipes  

SciTech Connect (OSTI)

An improved heat pipe design using separately connected two-section one-way flow heat pipes with internal microgrooves instead of wicks is described. This design is now commercially available for use to increase the dehumidification capacity of air conditioning systems. The design also includes a method of introducing fresh air into buildings while recovering heat and controlling the humidity of the incoming air. Included are applications and case studies, load calculations and technical data, and installation, operation, and maintenance information.

Not Available

1993-09-01T23:59:59.000Z

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.


461

CHP: It's Time for Combined Heat and Power  

E-Print Network [OSTI]

and export 16. Creates local jobs for installation, operation and maintenance 17. Supports competitive electricity market structure General Conclusion It is very much in the PUBLIC interest to support CHP distributed energy even if the private incentives... of use Electricity Electricity Heat Heat Combined Heat and Power Conventional Generation Building Load Power Plant fuel (66 units of remote energy) Boiler fuel (34 units of on-site energy) CHP fuel (x units of on-site energy) Losses Losses 20 29 20...

Herweck, R.

462

Heat recirculating cooler for fluid stream pollutant removal  

DOE Patents [OSTI]

A process by which heat is removed from a reactant fluid to reach the operating temperature of a known pollutant removal method and said heat is recirculated to raise the temperature of the product fluid. The process can be utilized whenever an intermediate step reaction requires a lower reaction temperature than the prior and next steps. The benefits of a heat-recirculating cooler include the ability to use known pollutant removal methods and increased thermal efficiency of the system.

Richards, George A. (Morgantown, WV); Berry, David A. (Morgantown, WV)

2008-10-28T23:59:59.000Z

463

Automatic Tube Cleaning Systems for Condensers and Heat Exchangers  

E-Print Network [OSTI]

AUTOMATIC TUBE CLEANING SYSTEMS FOR CONDENSERS AND HEAT EXCHANGERS Kaveh Someah/V.P. Sales & Mktg. WSA Engineered Systems, Milwaukee, WI (414) 354-6470 ABSTRACT The on-line Automatic Tube Cleaning Systems (ATCS) for condensers and heat... exchangers provide a positive means for automatic cleaning on a continuous basis, while the exchanger or condenser remains "on stream" and at its full operating potential. Condenser tube fouling contributes up to 50% of the total condenser tube heat...

Someah, K.

464

Heat Integrated Distillation through Use of Microchannel Technology  

Broader source: Energy.gov [DOE]

This factsheet describes a research project whose goal is to develop a breakthrough distillation process using Microchannel Process Technology to integrate heat transfer and separation into a single unit operation.

465

Designing Optimal Heat and Power Systems for Industrial Processes  

E-Print Network [OSTI]

Industrial heat and power systems are complex and not fully understood as integrated systems. Within the context of the overall manufacturing process, they represent enormous capital investments and substantially contribute to the total operating...

Rutkowski, M. A.; Witherell, W. D.

466

Thermosyphon coil arrangement for heat pump outdoor unit  

DOE Patents [OSTI]

For a heat pump, the outdoor unit is provided with a coil and a refrigerant flow arrangement there for which is such that in the heating mode of operation of the heat pump they operate in a thermosyphon fashion. The coil has a feed portion and an exit portion leading to a separator drum from which liquid refrigerant is returned through downcomer line for recirculation to the feed portion. The coil is tilted upwardly from entry to exit by the angle alpha to enhance the clearance of the two phases of refrigerant from each other in the heating mode of operation. There is no thermosyphon function in the cooling mode of operation. 9 figs.

Draper, R.

1984-05-22T23:59:59.000Z

467

Process Heating Assessment and Survey Tool | Department of Energy  

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

identifies the most energy-intensive equipment. The tool can be used to perform a heat balance that identifies major areas of energy use under various operating conditions and...

468

Introduction of Heat Recovery Chiller Control and Water System Design  

E-Print Network [OSTI]

The styles, feature and main concerns of heat recovery water system are discussed, and the entering condenser water temperature control is recommended for higher chiller efficiency and reliable operation. Three optimized water system designs...

Jia, J.

2006-01-01T23:59:59.000Z

469

Reduce Natural Gas Use in Your Industrial Process Heating Systems  

SciTech Connect (OSTI)

This DOE Industrial Program fact sheet describes ten effective ways to save energy and money in industrial process heating systems by making some changes in equipment, operations, and maintenance.

Not Available

2007-09-01T23:59:59.000Z

470

Thermosyphon coil arrangement for heat pump outdoor unit  

DOE Patents [OSTI]

For a heat pump, the outdoor unit is provided with a coil and a refrigerant flow arrangement therefor which is such that in the heating mode of operation of the heat pump they operate in a thermosyphon fashion. The coil 32 has a feed portion 30 and an exit portion 34 leading to a separator drum 36 from which liquid refrigerant is returned through downcomer line 42 for recirculation to the feed portion. The coil is tilted upwardly from entry to exit by the angle alpha to enhance the clearance of the two phases of refrigerant from each other in the heating mode of operation. There is no thermosyphon function in the cooling mode of operation.

Draper, Robert (Churchill, PA)

1984-01-01T23:59:59.000Z

471

DOE - Office of Legacy Management -- Tocco Induction Heating...  

Office of Legacy Management (LM)

, Ohio OH.42-1 Evaluation Year: 1994 OH.42-2 OH.42-3 Site Operations: Tested uranium heating methods during the late 1960s; only small amounts of material indicated. OH.42-1...

472

Anisotropic turbulent model for solar coronal heating  

E-Print Network [OSTI]

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

B. Bigot; S. Galtier; H. Politano

2007-12-12T23:59:59.000Z

473

Effects of slitted fins on the heat transfer and pressure drop characteristics of a compact heat exchanger  

SciTech Connect (OSTI)

A compact heat exchanger which consists of air-cooled aluminum fins and copper tubes circulating refrigerant has been used in a cooling system for a long time. There are two key parameters to be seriously considered for a design of the heat exchanger and its performance improvement. These are the heat transfer rate and pressure drop coefficient which varies with the change of the tube size, its arrangement and the fin configuration. In here, a numerical study was carried to understand the effect of the fin configuration on the heat transfer and pressure drop of the heat exchanger. The diameter and the arrangement of tubes were fixed but three different types of the fin configuration were used to see its effect on the heat transfer capacity and the static pressure drop. The calculation results were compared with that of a flat plate fin. From the comparison, it was found that the slitted fins have higher pressure drop; however, they have higher heat transfer rate. It means that the simpler of the fin configuration, the lower pressure drop and heat transfer coefficients are obtained. It is mainly due to the discretisation of the thermal boundary layer on the fin surface to maximize the heat transfer to air. The slitted sides of fins act like obstacles in the airflow path. From the experimental result, it was found that the same trend in the variation of the heat transfer rate and the pressure drop with the change of the fin configuration was obtained.

Kim, C.H.; Yun, J.Y. [LG Electronics Living System Research Lab., Seoul (Korea, Republic of)

1996-12-31T23:59:59.000Z

474

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

DOE Patents [OSTI]

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

Meisner, Gregory P

2013-10-08T23:59:59.000Z

475

Compressor Selection and Equipment Sizing for Cold Climate Heat Pumps  

SciTech Connect (OSTI)

In order to limit heating capacity degradation at -25 C (-13 F) ambient to 25%, compared to the nominal rating point capacity at 8.3 C (47 F), an extensive array of design and sizing options were investigated, based on fundamental equipment system modeling and building energy simulation. Sixteen equipment design options were evaluated in one commercial building and one residential building, respectively in seven cities. The energy simulation results were compared to three baseline cases: 100% electric resistance