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

Reduce Radiation Losses from Heating Equipment  

Science Conference Proceedings (OSTI)

This DOE Industrial Technologies Program tip sheet describes how to save energy and costs by reducing expensive heat losses from industrial heating equipment, such as furnaces.

Not Available

2006-01-01T23:59:59.000Z

2

Reducing heat loss from the energy absorber of a solar collector  

DOE Patents (OSTI)

A device is provided for reducing convective heat loss in a cylindrical radiant energy collector. It includes a curved reflective wall in the shape of the arc of a circle positioned on the opposite side of the exit aperture from the reflective side walls of the collector. Radiant energy exiting the exit aperture is directed by the curved wall onto an energy absorber such that the portion of the absorber upon which the energy is directed faces downward to reduce convective heat loss from the absorber.

Chao, Bei Tse (Urbana, IL); Rabl, Ari (Downers Grove, IL)

1976-01-01T23:59:59.000Z

3

Methods for reducing heat losses from flat plate solar collectors: Phase II. Final report, February 1, 1976--August 31, 1977  

DOE Green Energy (OSTI)

Improvements to flat plate solar collectors for heating and cooling of buildings were investigated through two parallel studies. The first study, which deals with the free convective heat loss from V-corrugated absorber plate to a plane glass cover, has shown that, for the same average spacing, the free convective heat loss is greater for a V-corrugated absorber plate than for a plane absorber plate. However, provided the average spacing is large enough, the amount of increase is slight. The second study, which deals with the free convective heat loss in a honeycomb solar collector in which the honeycomb consists of a set of horizontal partitions, or slits, has shown that provided the solar collector is tilted to near vertical, such a honeycomb gives equivalent or superior free convective loss suppression than does a square-celled honeycomb having the same amount of material. Correlation equations for the free convective heat loss are given for both studies.

Hollands, K.G.T.; Raithby, G.D.; Unny, T.E.

1978-03-01T23:59:59.000Z

4

Definition: Reduced Electricity Losses | Open Energy Information  

Open Energy Info (EERE)

Losses Losses Jump to: navigation, search Dictionary.png Reduced Electricity Losses Functions that provide this benefit could help manage peak feeder loads, reduced electricity throughput, locate electricity production closer to the load and ensure that voltages remain within service tolerances, while minimizing the amount of reactive power provided. These actions can reduce electricity losses by making the system more efficient for a given load served or by actually reducing the overall load on the system.[1] Related Terms load, electricity generation, reactive power, smart grid References ↑ SmartGrid.gov 'Description of Benefits' An inl LikeLike UnlikeLike You like this.Sign Up to see what your friends like. ine Glossary Definition Retrieved from "http://en.openei.org/w/index.php?title=Definition:Reduced_Electricity_Losses&oldid=502644

5

Study of Heat Loss: Commercial and Residential  

E-Print Network (OSTI)

There is much savings involved in the prevention of heat loss. Many structures exhibit such loss. Much can be done to improve or minimize the heat loss in a structure. These include interior and exterior modifications. It has been shown that heat can move by means of convection, conduction, and radiation. Problems with heat loss can be due to moisture, and poor construction techniques. There is a beneficial cost savings involved in the prevention of heat loss. Prevention techniques include insulation, caulking, weather stripping, and double pane windows. There are tables available for one to reference and calculate the return on their investment or “payback tim”

Emmett Ientilucci

1995-01-01T23:59:59.000Z

6

Heat loss from an open cavity  

DOE Green Energy (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

7

Aerodynamic Losses and Heat Transfer in a Blade Cascade with...  

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

Aerodynamic Losses and Heat Transfer in a Aerodynamic Losses and Heat Transfer in a Blade Cascade with 3 Blade Cascade with 3 - - D D Endwall Endwall Contouring Contouring...

8

Quantum cryptographic system with reduced data loss  

DOE Patents (OSTI)

A secure method for distributing a random cryptographic key with reduced data loss. Traditional quantum key distribution systems employ similar probabilities for the different communication modes and thus reject at least half of the transmitted data. The invention substantially reduces the amount of discarded data (those that are encoded and decoded in different communication modes e.g. using different operators) in quantum key distribution without compromising security by using significantly different probabilities for the different communication modes. Data is separated into various sets according to the actual operators used in the encoding and decoding process and the error rate for each set is determined individually. The invention increases the key distribution rate of the BB84 key distribution scheme proposed by Bennett and Brassard in 1984. Using the invention, the key distribution rate increases with the number of quantum signals transmitted and can be doubled asymptotically.

Lo, Hoi-Kwong (1309, Low Block, Lei Moon House Ap Lei Chau Estate, Hong Kong, HK); Chau, Hoi Fung (Flat C, 42nd Floor, Tower 1, University Heights 23 Pokfield Road, Pokfulam, Hong Kong, HK)

1998-01-01T23:59:59.000Z

9

Quantum cryptographic system with reduced data loss  

DOE Patents (OSTI)

A secure method for distributing a random cryptographic key with reduced data loss is disclosed. Traditional quantum key distribution systems employ similar probabilities for the different communication modes and thus reject at least half of the transmitted data. The invention substantially reduces the amount of discarded data (those that are encoded and decoded in different communication modes e.g. using different operators) in quantum key distribution without compromising security by using significantly different probabilities for the different communication modes. Data is separated into various sets according to the actual operators used in the encoding and decoding process and the error rate for each set is determined individually. The invention increases the key distribution rate of the BB84 key distribution scheme proposed by Bennett and Brassard in 1984. Using the invention, the key distribution rate increases with the number of quantum signals transmitted and can be doubled asymptotically. 23 figs.

Lo, H.K.; Chau, H.F.

1998-03-24T23:59:59.000Z

10

Reducing fischer-tropsch catalyst attrition losses in high ...  

Reducing fischer-tropsch catalyst attrition losses in high agitation reaction systems United States Patent

11

Parabolic Trough Receiver Heat Loss Testing (Poster)  

DOE Green Energy (OSTI)

Parabolic trough receivers, or heat collection elements (HCEs), absorb sunlight focused by the mirrors and transfer that thermal energy to a fluid flowing within them. Thje absorbing tube of these receivers typically operates around 400 C (752 F). HCE manufacturers prevent thermal loss from the absorbing tube to the environment by using sputtered selective Cermet coatings on the absorber and by surrounding the absorber with a glass-enclosed evacuated annulus. This work quantifies the heat loss of the Solel UVAC2 and Schott PTR70 HCEs. At 400 C, the HCEs perform similarly, losing about 400 W/m of HCE length. To put this in perspective, the incident beam radiation on a 5 m mirror aperture is about 4500 W/m, with about 75% of that energy ({approx} 3400 W/m) reaching the absorber surface. Of the 3400 W/m on the absorber, about 3000 W/m is absorbed into the working fluid while 400 W/m is lost to the environment.

Price, H.; Netter, J.; Bingham, C.; Kutscher, C.; Burkholder, F.; Brandemuehl, M.

2007-03-01T23:59:59.000Z

12

Reducing home heating and cooling costs  

SciTech Connect

This report is in response to a request from the House Committee on Energy and Commerce that the Energy Information Administration (EIA) undertake a neutral, unbiased analysis of the cost, safety, and health and environmental effects of the three major heating fuels: heating oil, natural gas, and electricity. The Committee also asked EIA to examine the role of conservation in the choice of heating and cooling fuel. To accommodate a wide audience, EIA decided to respond to the Committee`s request in the context of a report on reducing home heating and cooling costs. Accordingly, this report discusses ways to weatherize the home, compares the features of the three major heating and cooling fuels, and comments on the types of heating and cooling systems on the market. The report also includes a worksheet and supporting tables that will help in the selection of a heating and/or cooling system.

Not Available

1994-07-01T23:59:59.000Z

13

Correlation Of Surface Heat Loss And Total Energy Production...  

Open Energy Info (EERE)

Facebook icon Twitter icon Correlation Of Surface Heat Loss And Total Energy Production For Geothermal Systems Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home...

14

A Modelling of Heat Losses in Aluminium Reduction Cell with ...  

Science Conference Proceedings (OSTI)

Using of anodes with slots chanegd that heat transfer to a great extent.In order to Investigate heat loss dynamics in reduction cells with slot anodes,a modelling ...

15

Trough Receiver Heat Loss Testing (Presentation)  

DOE Green Energy (OSTI)

This presentation describes the design, fabrication, and qualification of an experimental capability for thermal loss testing of full-size trough receiver elements; and the testing on a variety of receivers.

Lewandowski, A.; Feik, C.; Hansen, R.; Phillips, S.; Bingham, C.; Netter, J.; Forristal, R.; Burkholder, F.; Meglan, B.; Wolfrum, E.

2006-02-01T23:59:59.000Z

16

Economics of heat loss for power cables  

SciTech Connect

Energy losses occur in power cables which cause a rise in the conductor temperature. A trend toward higher allowable conductor temperatures has increased the energy losses during operation. At the same time, the costs of the energy has increased dramatically. With a given installation and load, energy costs vary inversely with the conductor size. However, initial costs vary directly with the conductor size. This relationship can be utilized to select a conductor size which minimizes the sum of the initial costs an the energy costs. This paper reviews present value techniques and identifies the level of energy costs in some particular installation configurations. An analysis is made of the marginal costs and savings available by changing the size of the conductor in a cable circuit.

Cornelison, K.E.

1982-07-01T23:59:59.000Z

17

Evaluation of Using Infrared Thermography for quantifying Heat Losses From Buried Heat Distribution Pipes in chicago Housing Authority's Projects  

Science Conference Proceedings (OSTI)

Evaluation of using infrared thermography for quantifying heat losses from buried heat distribution pipes in Chicago Housing Authority's Projects

Gary Phetteplace

2001-05-29T23:59:59.000Z

18

Reducing Home Heating and Cooling Costs  

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

. . . . . . . . . . . . 19 B1. Annual Cost of Oil Heat in Various Climates for a Range of Heating Oil Prices and System Efficiencies . . . . . 21 B2. Annual Cost of Gas Heat in...

19

New waste-heat refrigeration unit cuts flaring, reduces pollution  

Science Conference Proceedings (OSTI)

Planetec Utility Services Co. Inc. and Energy Concepts Co. (ECC), with the help of the US Department of Energy (DOE), developed and commissioned a unique waste-heat powered LPG recovery plant in August 1997 at the 30,000 b/d Denver refinery, operated by Ultramar Diamond Shamrock (UDS). This new environmentally friendly technology reduces flare emissions and the loss of salable liquid-petroleum products to the fuel-gas system. The waste heat ammonia absorption refrigeration plant (Whaarp) is the first technology of its kind to use low-temperature waste heat (295 F) to achieve sub-zero refrigeration temperatures ({minus}40 F) with the capability of dual temperature loads in a refinery setting. The ammonia absorption refrigeration is applied to the refinery`s fuel-gas makeup streams to condense over 180 b/d of salable liquid hydrocarbon products. The recovered liquid, about 64,000 bbl/year of LPG and gasoline, increases annual refinery profits by nearly $1 million, while substantially reducing air pollution emissions from the refinery`s flare.

Brant, B.; Brueske, S. [Planetec Utility Services Co., Inc., Evergreen, CO (United States); Erickson, D.; Papar, R. [Energy Concepts Co., Annapolis, MD (United States)

1998-05-18T23:59:59.000Z

20

Plant View On Reducing Steam Trap Energy Loss  

E-Print Network (OSTI)

Energy will continue to be an ever increasingly important factor in the cost of doing business in the decade of the 80' s. In many petrochemical industries, energy is the second most costly item in producing a product. About 36% of our nation's total energy consumption is used by industry in producing the goods which are consumed around the world. Steam is the most commonly used energy source for the petrochemical industry. Most of this steam is used for heating and evaporating the many petrochemical liquids. This steam is then condensed and is removed from the system at the same rate as it is being formed or the loss of heat transfer will result. From a cost standpoint only condensate should be allowed through the trap. But at many plants half of the steam traps are passing excess steam. This is caused by neglect of aged steam traps which have worn out and misapplication of steam traps by oversizing or using the 'wrong' type trap. Elimination of steam wastes by an effective well engineered steam trap program is what is covered by this article.

Vallery, S. J.

1982-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduce heat loss" 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

Reduce Your Heating Bills with Better Insulation | Department of Energy  

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

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

22

Reduce Your Heating Bills with Better Insulation | Department of Energy  

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

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

23

Using Zeolites Synthesized from Fly Ash to Reduce Ammonia Loss to the Environment  

Science Conference Proceedings (OSTI)

This interim report describes studies using zeolites synthesized from fly ash to reduce ammonia loss to the environment.

2002-02-19T23:59:59.000Z

24

Heat-Loss Testing of Solel's UVAC3 Parabolic Trough Receiver  

DOE Green Energy (OSTI)

For heat-loss testing on two Solel UVAC3 parabolic trough receivers, a correlation developed predicts receiver heat loss as a function of the difference between avg absorber and ambient temperatures.

Burkholder, F.; Kutscher, C.

2008-01-01T23:59:59.000Z

25

Cascaded'' pilot regulators help reduce LPG loss in hot weather  

SciTech Connect

Fina Oil and Chemical Co. and Fisher Controls International used engineering resourcefulness to overcome heat-induced product loss from LPG storage bullets at Fina's Port Arthur, Tex., refinery. Fina had installed Fisher's Easy Joe 399A-6365, a pilot-operated, back-pressure-type regulator, on its LPG storage facility in 1991 as part of a fuel products modernization project. The regulators helped control the accumulation of noncondensible vapors, which collect in the storage bullets above the LPG. But summer heat extremes and surges in the tanks and lines made it possible for the operating pressure to increase so that the safety relief valve was activated before the pilot regulator was able to stabilize the pressure. The installation of pilot-type regulators, in cascaded, or series, formation, reduced product venting through relief valves.

1994-08-08T23:59:59.000Z

26

Convection heat loss from cavity receiver in parabolic dish solar thermal power system: A review  

SciTech Connect

The convection heat loss from cavity receiver in parabolic dish solar thermal power system can significantly reduce the efficiency and consequently the cost effectiveness of the system. It is important to assess this heat loss and subsequently improve the thermal performance of the receiver. This paper aims to present a comprehensive review and systematic summarization of the state of the art in the research and progress in this area. The efforts include the convection heat loss mechanism, experimental and numerical investigations on the cavity receivers with varied shapes that have been considered up to date, and the Nusselt number correlations developed for convection heat loss prediction as well as the wind effect. One of the most important features of this paper is that it has covered numerous cavity literatures encountered in various other engineering systems, such as those in electronic cooling devices and buildings. The studies related to those applications may provide valuable information for the solar receiver design, which may otherwise be ignored by a solar system designer. Finally, future development directions and the issues that need to be further investigated are also suggested. It is believed that this comprehensive review will be beneficial to the design, simulation, performance assessment and applications of the solar parabolic dish cavity receivers. (author)

Wu, Shuang-Ying; Xiao, Lan; Li, You-Rong [College of Power Engineering, Chongqing University, Chongqing 400044 (China); Cao, Yiding [Department of Mechanical and Materials Engineering, Florida International University, Miami, FL 33174 (United States)

2010-08-15T23:59:59.000Z

27

Reducing exergy losses of liquid fluid using embedded open parallel microchannels within the surface  

Science Conference Proceedings (OSTI)

This paper presents an analysis of entropy generation of forced convection heat transfer of liquid fluid over the horizontal surface with embedded open parallel microchannels at constant heat flux boundary conditions. The governing partial differential ... Keywords: constant heat flux, embedded open parallel microchannels, entropy generation, exergy losses, liquid fluid

M. H. Yazdi; S. Abdullah; I. Hashim; K. Sopian

2008-12-01T23:59:59.000Z

28

Study of high energy ion loss during hydrogen minority heating in TFTR  

DOE Green Energy (OSTI)

High energy ion loss during hydrogen minority ICRF heating is measured and compared with the loss of the D-D fusion products. During H minority heating a relatively large loss of high energy ions is observed at 45{degrees} below the outer midplane, with or without simultaneous NBI heating. This increase is most likely due to a loss of the minority tail protons, a possible model for this process is described.

Park, J.; Zweben, S.J.

1994-03-01T23:59:59.000Z

29

PKL experiments on loss of residual heat removal under shutdown conditions in PWRS  

SciTech Connect

When a pressurized water reactor (PWR) is shutdown for refueling, the main coolant inventory is reduced so that the level is at mid-loop elevation. Removal of the decay heat from the core is maintained by the residual heat removal system (RHRS), which under these conditions represents the only heat sink. Loss of RHRS under shutdown conditions has occurred several times worldwide and still plays an important role in risk studies for PWRs. The experimental investigation on loss of RHRS is one mayor topic in the current PKL test program which is included in an international project set up by the OECD. PKL is an integral test facility simulating a typical western-type 1300 MW PWR and is used to investigate the thermal-hydraulic system behavior of PWRs under accident situations. The PKL test facility is operated in the Technical Center of Framatome ANP in Erlangen, Germany. The tests on loss of RHRS have been performed with borated water and special measurement techniques for the determination of the boron concentration (online measurements). The PKL tests demonstrate that, as long as the primary circuit is closed, a failure of the residual heat removal system can be compensated by one or more steam generators, which remain filled with water on the secondary side and stay ready for use during refueling and other outages. However, the tests showed also that accumulations of large condensate inventories (with low boron concentration) can occur in the cold leg piping during mid-loop operation after loss of the RHRS. This paper summarizes the most important results of a PKL experiment dealing with loss of RHRS during mid-loop operation with closed primary circuit. Issues still open and needs for further investigations are also discussed. (authors)

Umminger, Klaus; Schoen, Bernhard; Mull, Thomas [Framatome ANP GmbH, Freyeslebenstrasse 1, 91058 Erlangen (Germany)

2006-07-01T23:59:59.000Z

30

Reduced-risk HTGR concept for industrial-heat application  

SciTech Connect

The industrial process heat market has been identified as major market for the High Temperature Gas-Cooled Reactor (HTGR), however, this market introduces stringent availability requirements on the reactor system relative to electric plants which feed a large existing grid. The characteristics and requirements of the industrial heat markets are summarized; the risks associated with serving this market with a single large HTGR will be discussed; and the modular concept, which has the potential to reduce both safety and investment risks, will be described. The reference modular concept described consists of several small, relatively benign nuclear heat sources linked together to supply heat energy to a balance-of-plant incorporating a process gas train/thermochemical pipe line system and a normal steam-electric plant.

Boardman, C.E.; Lipps, A.J.

1982-06-01T23:59:59.000Z

31

An Analysis of Loss of Decay Heat Removal and Loss of Inventory Event Trends (1990-2009)  

Science Conference Proceedings (OSTI)

In recent years, there has been an observed increase in plant events during shutdown conditions. This has increased interest among the industry and the United States Nuclear Regulatory Commission to obtain a better understanding of the data and the trends. This report documents a long-term study of loss of decay heat removal and loss of inventory events during shutdown conditions in the nuclear industry, spanning a 20-year period from 1990 through 2009. The EPRI reports An Analysis of Loss of Decay Heat ...

2010-12-17T23:59:59.000Z

32

GASLESS COMBUSTION FRONTS WITH HEAT LOSS ANNA GHAZARYAN, STEPHEN SCHECTER, AND PETER L. SIMON  

E-Print Network (OSTI)

GASLESS COMBUSTION FRONTS WITH HEAT LOSS ANNA GHAZARYAN, STEPHEN SCHECTER, AND PETER L. SIMON Abstract. For a model of gasless combustion with heat loss, we use geometric singular perturbation theory to show existence of traveling combustion fronts. We show that the fronts are nonlinearly stable

Schecter, Stephen

33

Reduced Loss in Precipitation Measurements Using a New Wind Shield for Raingages  

Science Conference Proceedings (OSTI)

A problem of great concern in precipitation measurements is the wind loss. This paper presents a new wind shield that reduces this loss. Tests of the new shield were made in a wind tunnel and in the field. The wind shield consisted of a flange ...

Anders Lindroth

1991-06-01T23:59:59.000Z

34

Effect of Cavity Wall Temperature and Opening Ratio on the Natural Convection Heat Loss Characteristics of a Solar Cavity Receiver  

Science Conference Proceedings (OSTI)

The natural convection heat loss characteristics of a solar cavity receiver have been investigated by numerical simulation method. The results show that, the natural convection heat loss, the convection heat transfer coefficient and Nusselt number increase ... Keywords: solar cavity receiver, cavity wall temperature, opening ratio, natural convection heat loss

Lan Xiao; Shuang-Ying Wu; You-Rong Li

2011-02-01T23:59:59.000Z

35

O&M First! Actions You Can Take to Reduce Heating Costs  

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

Fact Sheet Actions You Can Take to Reduce Heating Costs Heating accounts for a significant energy load and usually presents a number of opportunities to improve performance and...

36

Electric coheating experiment to determine the heat-loss coefficient of a double-envelope house  

DOE Green Energy (OSTI)

An electric coheating experiment was conducted on a double-envelope house in Arvada, Colorado, to determine the total heat loss coefficient (UA) of the double-shelled structure, as well as the heat loss coefficients of the inner and outer shells. Electric coheating is fairly well established as an experimental method for determining the total heat loss coefficient in conventional residential buildings. However, special problems are introduced with passive and double-envelope buildings. A new methodology was developed to meet these problems. That methodology and the results of the experimental investigation are presented and discussed.

Ortega, J. K.E.; Anderson, J. V.; Connolly, J. M.; Bingham, C. E.

1981-07-01T23:59:59.000Z

37

Boiler Blowdown Heat Recovery Project Reduces Steam System Energy...  

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

produced. Much of this heat can be recovered by routing the blown down liquid through a heat exchanger that preheats the boiler's makeup water. A boiler blowdown heat recovery...

38

Aerodynamic Losses and Heat Transfer in a Blade Cascade with 3-D Endwall Contouring  

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

Aerodynamic Losses and Heat Transfer in a Aerodynamic Losses and Heat Transfer in a Aerodynamic Losses and Heat Transfer in a Aerodynamic Losses and Heat Transfer in a Blade Cascade with 3 Blade Cascade with 3 - - D D Endwall Endwall Contouring Contouring Principal Investigator Principal Investigator Sumanta Acharya, Professor Sumanta Acharya, Professor Louisiana State University, Baton Rouge, Louisiana Louisiana State University, Baton Rouge, Louisiana Collaborators Collaborators Gazi Mahmood, Ph.D., Research Asqociate Gazi Mahmood, Ph.D., Research Asqociate Arun Saha, Ph.D., Research Associate Arun Saha, Ph.D., Research Associate Ross Gustafson, M.S. student Ross Gustafson, M.S. student SCIES Project 02 SCIES Project 02 - - 01 01 - - SR098 SR098 DOE COOPERATIVE AGREEMENT DE DOE COOPERATIVE AGREEMENT DE - - FC26 FC26 - - 02NT41431 02NT41431 Tom J. George, Program Manager, DOE/NETL

39

Detecting sources of heat loss in residential buildings from infrared imaging  

E-Print Network (OSTI)

Infrared image analysis was conducted to determine the most common sources of heat loss during the winter in residential buildings. 135 houses in the greater Boston and Cambridge area were photographed, stitched, and tallied ...

Shao, Emily Chen

2011-01-01T23:59:59.000Z

40

An improved model for natural convection heat loss from modified cavity receiver of solar dish concentrator  

Science Conference Proceedings (OSTI)

A 2-D model has been proposed to investigate the approximate estimation of the natural convection heat loss from modified cavity receiver of without insulation (WOI) and with insulation (WI) at the bottom of the aperture plane in our previous article. In this paper, a 3-D numerical model is presented to investigate the accurate estimation of natural convection heat loss from modified cavity receiver (WOI) of fuzzy focal solar dish concentrator. A comparison of 2-D and 3-D natural convection heat loss from a modified cavity receiver is carried out. A parametric study is carried out to develop separate Nusselt number correlations for 2-D and 3-D geometries of modified cavity receiver for estimation of convective heat loss from the receiver. The results show that the 2-D and 3-D are comparable only at higher angle of inclinations (60 {solar dish collector, when compared with other well known models. (author)

Reddy, K.S.; Sendhil Kumar, N. [Heat Transfer and Thermal Power Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai, Tamilnadu 600036 (India)

2009-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "reduce heat loss" 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

Wind effects on convective heat loss from a cavity receiver for a parabolic concentrating solar collector  

DOE Green Energy (OSTI)

Tests were performed to determine the convective heat loss characteristics of a cavity receiver for a parabolid dish concentrating solar collector for various tilt angles and wind speeds of 0-24 mph. Natural (no wind) convective heat loss from the receiver is the highest for a horizontal receiver orientation and negligible with the reveler facing straight down. Convection from the receiver is substantially increased by the presence of side-on wind for all receiver tilt angles. For head-on wind, convective heat loss with the receiver facing straight down is approximately the same as that for side-on wind. Overall it was found that for wind speeds of 20--24 mph, convective heat loss from the receiver can be as much as three times that occurring without wind.

Ma, R.Y. [California State Polytechnic Univ., Pomoma, CA (United States). Dept. of Mechanical Engineering

1993-09-01T23:59:59.000Z

42

Correlation Of Surface Heat Loss And Total Energy Production For Geothermal  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Correlation Of Surface Heat Loss And Total Energy Production For Geothermal Systems Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Correlation Of Surface Heat Loss And Total Energy Production For Geothermal Systems Details Activities (1) Areas (1) Regions (0) Abstract: Geothermal systems lose their heat by a site-specific combination of conduction (heat flow) and advection (surface discharge). The conductive loss at or near the surface (shallow heat flow) is a primary signature and indication of the strength of a geothermal system. Using a database of

43

Oscillating flow loss test results in Stirling engine heat exchangers. Final Report  

SciTech Connect

The results are presented for a test program designed to generate a database of oscillating flow loss information that is applicable to Stirling engine heat exchangers. The tests were performed on heater/cooler tubes of various lengths and entrance/exit configurations, on stacked and sintered screen regenerators of various wire diameters and on Brunswick and Metex random fiber regenerators. The test results were performed over a range of oscillating flow parameters consistent with Stirling engine heat exchanger experience. The tests were performed on the Sunpower oscillating flow loss rig which is based on a variable stroke and variable frequency linear drive motor. In general, the results are presented by comparing the measured oscillating flow losses to the calculated flow losses. The calculated losses are based on the cycle integration of steady flow friction factors and entrance/exit loss coefficients.

Koester, G.; Howell, S.; Wood, G.; Miller, E.; Gedeon, D.

1990-05-01T23:59:59.000Z

44

Roof shading and wall glazing techniques for reducing peak building heating and cooling loads. Final report  

SciTech Connect

The roof shading device proved to be effective in reducing peak building cooling loads under both actual testing conditions and in selected computer simulations. The magnitude of cooling load reductions varied from case to case depending on individual circumstances. Key variables that had significant impacts on its thermal performance were the number of months of use annually, the thermal characteristics of the roof construction, hours of building use, and internal gains. Key variables that had significant impacts upon economic performance were the costs of fuel energy for heating and cooling, and heating and cooling equipment efficiency. In general, the more sensitive the building is to climate, the more effective the shading device will be. In the example case, the annual fuel savings ($.05 psf) were 6 to 10% of the estimated installation costs ($.50 to .75 psf). The Trombe wall installation at Roxborough High School proved to be effective in collecting and delivering significant amounts of solar heat energy. It was also effective in conserving heat energy by replacing obsolete windows which leaked large amounts of heat from the building. Cost values were computed for both solar energy contributions and for heat loss reductions by window replacement. Together they amount to an estimated three hundred and ninety dollars ($390.00) per year in equivalent electric fuel costs. When these savings are compared with installation cost figures it is apparent that the Trombe wall installation as designed and installed presents a potentially cost-effective method of saving fuel costs. The study results indicate that improved Trombe wall efficiency can be achieved by making design and construction changes to reduce or eliminate outside air leakage into the system and provide automatic fan control.

Ueland, M.

1981-08-01T23:59:59.000Z

45

Question of the Week: How Do You Reduce Your Water Heating Costs |  

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

Reduce Your Water Heating Costs Reduce Your Water Heating Costs Question of the Week: How Do You Reduce Your Water Heating Costs February 19, 2009 - 1:39pm Addthis Water heating can account for a significant portion of your energy costs. Purchasing a new ENERGY STAR® water heater is just one way to save on your water heating bills. The Energy Savers Tips site lists other strategies you can use to cut your water heating costs. How do you reduce your water heating costs? E-mail your responses to the Energy Saver team at consumer.webmaster@nrel.gov. Addthis Related Articles Question of the Week: How Do You Reduce Your Water Heating Costs Energy Savers Guide: Tips on Saving Money and Energy at Home How Do You Save on Lighting Costs? Question of the Week: How Do You Reduce Your Water Heating Costs

46

Reducing Thermal Losses and Gains With Buried and Encapsulated Ducts in Hot-Humid Climates  

SciTech Connect

The Consortium for Advanced Residential Buildings (CARB) monitored three houses in Jacksonville, FL, to investigate the effectiveness of encapsulated and encapsulated/buried ducts in reducing thermal losses and gains from ductwork in unconditioned attics. Burying ductwork beneath loose-fill insulation has been identified as an effective method of reducing thermal losses and gains from ductwork in dry climates, but it is not applicable in humid climates where condensation may occur on the outside of the duct jacket. By encapsulating the ductwork in closed cell polyurethane foam (ccSPF) before burial beneath loose-fill mineral fiber insulation, the condensation potential may be reduced while increasing the R-value of the ductwork.

Shapiro, C.; Magee, A.; Zoeller, W.

2013-02-01T23:59:59.000Z

47

Reduce Natural Gas Use in Your Industrial Process Heating Systems  

Science Conference Proceedings (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

48

Determination of freeze-protection heat loss from a parabolic trough solar system  

DOE Green Energy (OSTI)

A small-scale experiment was undertaken to determine practical control temperatures for a parabolic trough, pulsed-flow water freeze-protection scheme. Measurements were also taken of heat loss from stagnant water in the absorber tube under freezing ambient conditions. Using the experimental data and data available from the literature, manipulation of long-term weather data provided estimates of annual thermal losses to prevent freezing. In a cold climate such as Denver, Colorado's, which typically has 155 freezing days per year, such losses should be less than 0.7% of the annual energy delivered by an efficient parabolic trough system.

May, E.K.

1983-08-01T23:59:59.000Z

49

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

DOE Green Energy (OSTI)

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

Not Available

2004-11-01T23:59:59.000Z

50

Gas Water Heater Energy Losses  

E-Print Network (OSTI)

non-firing, non- recovery mode, i.e. , during standby mode.The stack losses while in standby mode account for about 43%can be made by reducing standby heat losses. This paper

Biermayer, Peter

2012-01-01T23:59:59.000Z

51

How Do You Use Daylighting While Reducing Excess Heat from Windows? |  

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

Do You Use Daylighting While Reducing Excess Heat from Windows? Do You Use Daylighting While Reducing Excess Heat from Windows? How Do You Use Daylighting While Reducing Excess Heat from Windows? June 16, 2011 - 7:30am Addthis On Monday, Elizabeth discussed her south-facing windows and her difficulties balancing the nice daylighting advantages with the excess heat that can come through these windows in the summer. How do you use daylighting while reducing excess heat from windows? Each Thursday, you have the chance to share your thoughts on a question about energy efficiency or renewable energy for consumers. E-mail your responses to the Energy Saver team at consumer.webmaster@nrel.gov. Addthis Related Articles Fighting with South-Facing Windows This Month on Energy Savers: June 2011 Simple and inexpensive actions can help you save energy and money during the warm spring and summer months. | Photo courtesy of iStockphoto.com/eyedias.

52

Reducing fischer-tropsch catalyst attrition losses in high agitation reaction systems  

DOE Patents (OSTI)

A method for reducing catalyst attrition losses in hydrocarbon synthesis processes conducted in high agitation reaction systems; a method of producing an attrition-resistant catalyst; a catalyst produced by such method; a method of producing an attrition-resistant catalyst support; and a catalyst support produced by such method. The inventive method of reducing catalyst attrition losses comprises the step of reacting a synthesis gas in a high agitation reaction system in the presence of a catalyst. In one aspect, the catalyst preferably comprises a .gamma.-alumina support including an amount of titanium effective for increasing the attrition resistance of the catalyst. In another aspect, the catalyst preferably comprises a .gamma.-alumina support which has been treated, after calcination, with an acidic, aqueous solution. The acidic aqueous solution preferably has a pH of not more than about 5. In another aspect, the catalyst preferably comprises cobalt on a .gamma.-alumina support wherein the cobalt has been applied to the .gamma.-alumina support by totally aqueous, incipient wetness-type impregnation. In another aspect, the catalyst preferably comprises cobalt on a .gamma.-alumina support with an amount of a lanthana promoter effective for increasing the attrition resistance of the catalyst. In another aspect, the catalyst preferably comprises a .gamma.-alumina support produced from boehmite having a crystallite size, in the 021 plane, in the range of from about 30 to about 55 .ANG.ngstrons. In another aspect, the inventive method of producing an attrition-resistant catalyst comprises the step of treating a .gamma.-alumina support, after calcination of and before adding catalytic material to the support, with an acidic solution effective for increasing the attrition resistance of the catalyst. In another aspect, the inventive method of producing an attrition-resistant catalyst support comprises the step of treating calcined .gamma.-alumina with an acidic, aqueous solution effective for increasing the attrition resistance of the .gamma.-alumina.

Singleton, Alan H. (Baden, PA); Oukaci, Rachid (Gibsonia, PA); Goodwin, James G. (Cranberry Township, PA)

2001-01-01T23:59:59.000Z

53

An Analysis of loss of Decay Heat Removal Trends and Initialing Event Frequencies (1989-1988): Outage Risk Assessment and Management (ORAM) Technology  

Science Conference Proceedings (OSTI)

Operating experience shows that U.S. nuclear industry initiatives have been effective at reducing the frequency and severity of reactor coolant system loss of inventory and decay heat removal incidents during shutdown. This report -- part of EPRI's Outage Risk Assessment and Management (ORAM) technology transfer efforts -- documents operating experience from 1989-1998 and compiles initiating event frequency and recovery probabilities for use in support of probabilistic shutdown safety studies.

1999-10-20T23:59:59.000Z

54

An Analysis of Loss of Decay Heat Removal Trends and Initiating Event Frequencies (1989 - 2000): Outage Risk Assessment and Manageme nt (ORAM) Technology  

Science Conference Proceedings (OSTI)

Operating experience shows that U.S. nuclear industry initiatives have been effective at reducing the long-term frequency and severity of reactor coolant system loss of inventory and decay heat removal incidents during shutdown. This report -- part of EPRI's Outage Risk Assessment and Management (ORAM (TM)) technology transfer efforts -- documents operating experience from 1989-2000 and compiles initiating event frequency and recovery probabilities for use in support of probabilistic shutdown safety stud...

2001-11-30T23:59:59.000Z

55

A scheme for reducing experimental heat capacity data of gas hydrates  

SciTech Connect

Experimental heat capacity data of simple gas hydrates on xenon, methane, ethane, and propane are reduced by application of classical thermodynamics and the ideal solid solution theory. It is shown that calculated heat capacities of the empty hydrate lattices of the structure 1 and 2 hydrates can be higher or lower than the heat capacity of ice. Similarly, the calculated partial molar heat capacity of the enclathrated gases are higher or lower than the corresponding experimental ideal gas heat capacity. These differences depend on the size of the guest relative to the cavity, the hydrate number, and the temperature. For estimation of the thermodynamic properties of the empty hydrate lattice, further experimental work is recommended. Within the present limitations, a consistent methodology is applied for the prediction of the heat capacity of a natural gas hydrate.

Avlonitis, D. (Aero-engines Factory, Elefsis (Greece). Division of Chemistry)

1994-12-01T23:59:59.000Z

56

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

Science Conference Proceedings (OSTI)

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

VIlim, R.; Nuclear Engineering Division

2009-03-12T23:59:59.000Z

57

Packet erasure coding with random access to reduce losses of delay sensitive multislot messages  

E-Print Network (OSTI)

Many commercial and military systems use some form of random access. ALOHA type protocols are particularly useful for multicast traffic and have low complexity; however, they suffer from low capacity and large loss ...

Zeger, Linda

58

The Heat Loss Analysis and Commissioning of a Commercial Helium Dewar (SULI paper)  

SciTech Connect

A low temperature cryostat suitable for many different experiments will be commissioned at the cryogenic test facility at SLAC. The scope of the project is to make commission a commercial Helium dewar. The building of the top flange will be followed from its design phase through to its finished assembly. In addition, diagnostic tools such as thermometry, level detector, pressure gauge, transfer lines for He and N2, vent lines with relief valves for He and N2 will be incorporated. Instrumentation to read and plot this data will also be included. Once the cryostat is assembled, we will cool down the cryostat to measure its performance. A typical consumption rate of Helium will be measured and from this, the overall heat leak to the dewar will be calculated. A processing instrumentation diagram (PID) of the dewar system was created with SolidEdge and was later approved and published as an official SLAC document. The plots comparing the liquid level changes of the 36 inch probe with the time and the heat loss as a function of time proved to be a valid indication that the data was interpreted and recorded correctly and that the dewar was put together successfully.

Bellamy, Marcus; /New Mexico U. /SLAC

2006-01-04T23:59:59.000Z

59

A Reduced-Boundary-Function Method for Convective Heat Transfer With Axial Heat Conduction and Viscous Dissipation  

Science Conference Proceedings (OSTI)

We introduce a new method of solution for the convective heat transfer under forced laminar flow that is confined by two parallel plates with a distance of 2a or by a circular tube with a radius of a. The advection-conduction equation is first mapped onto the boundary. The original problem of solving the unknown field T(x,r,t) is reduced to seek the solutions of T at the boundary (r = a or r = 0, r is the distance from the centerline shown in Fig. 1), i.e., the boundary functions T{sub a}(x,t) {triple_bond} T(x,r=a,t) and/or T{sub 0}(x,t) {triple_bond} T(x,r=0,t). In this manner, the original problem is significantly simplified by reducing the problem dimensionality from 3 to 2. The unknown field T(x,r,t) can be eventually solved in terms of these boundary functions. The method is applied to the convective heat transfer with uniform wall temperature boundary condition and with heat exchange between flowing fluids and its surroundings that is relevant to the geothermal applications. Analytical solutions are presented and validated for the steady-state problem using the proposed method.

Zhijie Xu

2012-07-01T23:59:59.000Z

60

A Reduced-Boundary-Function Method for Convective Heat Transfer with Axial Heat Conduction and Viscous Dissipation  

Science Conference Proceedings (OSTI)

We introduce a method of solution for the convective heat transfer under forced laminar flow that is confined by two parallel plates with a distance of 2a or by a circular tube with a radius of a. The advection-conduction equation is first mapped onto the boundary. The original problem of solving the unknown field is reduced to seek the solutions of T at the boundary (r=a or r=0, r is the distance from the centerline shown in Fig. 1), i.e. the boundary functions and/or . In this manner, the original problem is significantly simplified by reducing the problem dimensionality from 3 to 2. The unknown field can be eventually solved in terms of these boundary functions. The method is applied to the convective heat transfer with uniform wall temperature boundary condition and with heat exchange between flowing fluids and its surroundings that is relevant to the geothermal applications. Analytical solutions are presented and validated for the steady state problem using the proposed method.

Xu, Zhijie

2012-07-01T23:59:59.000Z

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61

A method to determine stratification efficiency of thermal energy storage processes independently from storage heat losses  

Science Conference Proceedings (OSTI)

A new method for the calculation of a stratification efficiency of thermal energy storages based on the second law of thermodynamics is presented. The biasing influence of heat losses is studied theoretically and experimentally. Theoretically, it does not make a difference if the stratification efficiency is calculated based on entropy balances or based on exergy balances. In practice, however, exergy balances are less affected by measurement uncertainties, whereas entropy balances can not be recommended if measurement uncertainties are not corrected in a way that the energy balance of the storage process is in agreement with the first law of thermodynamics. A comparison of the stratification efficiencies obtained from experimental results of charging, standby, and discharging processes gives meaningful insights into the different mixing behaviors of a storage tank that is charged and discharged directly, and a tank-in-tank system whose outer tank is charged and the inner tank is discharged thereafter. The new method has a great potential for the comparison of the stratification efficiencies of thermal energy storages and storage components such as stratifying devices. (author)

Haller, Michel Y.; Streicher, Wolfgang [Institute of Thermal Engineering, Graz University of Technology, Inffeldgasse 25/B, 8010 Graz (Austria); Yazdanshenas, Eshagh; Andersen, Elsa; Furbo, Simon [Department of Civil Engineering, Technical University of Denmark, Brovej, Building 118, DK-2800, Kgs. Lyngby (Denmark); Bales, Chris [Solar Energy Research Center SERC, Hoegskolan Dalarna, 781 88 Borlaenge (Sweden)

2010-06-15T23:59:59.000Z

62

Reduced energy consumption by massive thermoelectric waste heat recovery in light duty trucks  

Science Conference Proceedings (OSTI)

The main objective of the EC funded HEATRECAR project is to reduce the energy consumption and curb CO2 emissions of vehicles by massively harvesting electrical energy from the exhaust system and re-use this energy to supply electrical components within the vehicle or to feed the power train of hybrid electrical vehicles. HEATRECAR is targeting light duty trucks and focuses on the development and the optimization of a Thermo Electric Generator (TEG) including heat exchanger

D. Magnetto; G. Vidiella

2012-01-01T23:59:59.000Z

63

What`s new in building energy research: Thermal distribution technology. DOE looks at cutting energy losses in a building`s heating and cooling distribution system  

SciTech Connect

The Department of Energy takes a look at cutting energy losses in a building`s heating and cooling distribution system.

1995-11-01T23:59:59.000Z

64

Photoreversible Micellar Solution as a Smart Drag-Reducing Fluid for Use in District Heating/Cooling Systems  

E-Print Network (OSTI)

Photoreversible Micellar Solution as a Smart Drag-Reducing Fluid for Use in District Heating solution is developed as a promising working fluid for district heating/cooling systems (DHCs). It can systems. A promising application of DR fluids is in district heating/ cooling systems (DHCs)9

Raghavan, Srinivasa

65

A Prototype Roof Deck Designed to Self-Regulate Deck Temperature and Reduce Heat Transfer  

SciTech Connect

A prototype roof and attic assembly exploits the use of radiation, convection and insulation controls to reduce the heat transfer penetrating its roof deck by almost 85% of the heat transfer crossing a conventional roof and attic assembly. The assembly exhibited attic air temperatures that did not exceed the peak day outdoor ambient temperature. The design includes a passive ventilation scheme that pulls air from the soffit and attic into an inclined air space above the deck. The design complies with fire protection codes because the air intake is internal and closed to the elements. Field data were benchmarked against an attic computer tool and simulations made for new and retrofit home constructions in hot, moderate and cold climates to access economics for the assembly.

Miller, William A [ORNL

2011-01-01T23:59:59.000Z

66

A Prototype Roof Deck Designed to Self-Regulate Deck Temperature and Reduce Heat Transfer  

Science Conference Proceedings (OSTI)

A prototype roof and attic assembly exploits the use of radiation, convection and insulation controls to reduce its peak day heat transfer by almost 85 percent of the heat transfer crossing a conventional roof and attic assembly. The assembly exhibits attic air temperatures that do not exceed the maximum daily outdoor ambient temperature. The design includes a passive ventilation scheme that pulls air from the soffit and attic into an inclined air space above the roof deck. The design complies with fire protection codes because the air intake is internal and closed to the elements. Field data were benchmarked against an attic computer tool and simulations made for new and retrofit constructions in hot, moderate and cold climates to gauge the cost of energy savings and potential payback.

Miller, William A [ORNL

2011-01-01T23:59:59.000Z

67

Process and apparatus for reducing the loss of hydrogen from Stirling engines  

SciTech Connect

A Stirling engine assembly is described which defines a working gas volume therein, the Stirling engine assembly comprising: a working gas reservoir for storing a working gas at a pressure greater than pressure of the working gas in the working volume of the Stirling engine; a trap cell operatively connected between an outlet of the reservoir and the Stirling engine working volume. The trap cell includes an enclosure having porous windows at either end thereof and a sorbent with an affinity for water vapor therein, such that water vapor adsorbed on the sorbent diffuses into the hydrogen passing from the reservoir into the working engine; a compressor means for drawing working gas from the Stirling engine working volume, through the trap cell and pumping the working gas into the hydrogen reservoir. The sorbent in the trap cell at the reduced pressure caused by the compressor adsorbs water vapor from the working gas such that substantially dry working gas is pumped by the compressor into the reservoir. The working gas is doped with water vapor by the tank cell as it passes into the Stirling engine and is dried by the trap cell as it is removed from the working engine for storage in the reservoir to prevent condensation of water vapor in the reservoir.

Alger, D.L.

1987-03-24T23:59:59.000Z

68

Proposed Design for a Coupled Ground-Source Heat Pump/Energy Recovery Ventilator System to Reduce Building Energy Demand.  

E-Print Network (OSTI)

??The work presented in this thesis focuses on reducing the energy demand of a residential building by using a coupled ground-source heat pump/energy recovery ventilation… (more)

McDaniel, Matthew Lee

2011-01-01T23:59:59.000Z

69

Plasma ion heating and energy loss from alpha-particle micro-instabilities  

Science Conference Proceedings (OSTI)

An engineering model is described which scopes the effect of a velocity space relaxation of fast alphas on a quasi-linear time scale. An approximation for the ion heating is given. (MOW)

Sutton, W.R.; Choi, C.K.; Miley, G.H.

1981-01-01T23:59:59.000Z

70

Sulfur content of heating oil to be reduced in northeastern states ...  

U.S. Energy Information Administration (EIA)

Also, the Northeast Home Heating Oil Reserve has switched to ULSD. The Northeast is the largest regional consumer of heating oil in the United States.

71

Energy Model Development and Heating Energy Investigation of the Nested Thermal Envelope Design (NTED (tm)).  

E-Print Network (OSTI)

??Space heating accounts for approximately 60% of residential energy use in Canada. Minimizing envelope heat losses is one approach to reducing this percentage. Preliminary research… (more)

DIxon, Erin Elizabeth

2010-01-01T23:59:59.000Z

72

Isochoric heating of reduced mass targets by ultra-intense laser produced relativistic electrons  

Science Conference Proceedings (OSTI)

We present measurements of the chlorine K-alpha emission from reduced mass targets, irradiated with ultra-high intensity laser pulses. Chlorinated plastic targets with diameters down to 50 micrometers and mass of a few 10{sup -8} g were irradiated with up to 7 J of laser energy focused to intensities of several 10{sup 19} W/cm{sup 2}. The conversion of laser energy to K-alpha radiation is measured, as well as high resolution spectra that allow observation of line shifts, indicating isochoric heating of the target up to 18 eV. A zero-dimensional 2-temperature equilibration model, combined with electron impact K-shell ionization and post processed spectra from collisional radiative calculations reproduces the observed K-alpha yields and line shifts, and shows the importance of target expansion due to the hot electron pressure.

Neumayer, P; Lee, H J; Offerman, D; Shipton, E; Kemp, A; Kritcher, A L; Doppner, T; Back, C A; Glenzer, S H

2009-02-04T23:59:59.000Z

73

Generation of a Parabolic Trough Collector Efficiency Curve from Separate Measurements of Outdoor Optical Efficiency and Indoor Receiver Heat Loss  

SciTech Connect

The thermal efficiency of a parabolic trough collector is a function of both the fraction of direct normal radiation absorbed by the receiver (the optical efficiency) and the heat lost to the environment when the receiver is at operating temperature. The thermal efficiency can be determined by testing the collector under actual operating conditions or by separately measuring these two components. This paper describes how outdoor measurement of the optical efficiency is combined with laboratory measurements of receiver heat loss to obtain the thermal efficiency curve. This paper describes this approach and also makes the case that there are advantages to plotting collector efficiency versus the difference between the operating temperature and the ambient temperature at which the receiver heat loss was measured divided by radiation to a fractional power (on the order of 1/3 but obtained via data regression) - as opposed to the difference between operating and ambient temperatures divided by the radiation. The results are shown to be robust over wide ranges of ambient temperature, sky temperature, and wind speed.

Kutscher, C.; Burkholder, F.; Stynes, J. K.

2012-02-01T23:59:59.000Z

74

Downward two-phase flow effects in heat-loss and pressure-drop modeling of steam injection wells  

SciTech Connect

Modelling of the pressure drop and heat loss in steam injection wells has undergone a gradual evolution since the heavy interest in enhanced oil recovery by steam injection in the mid-60's. After briefly reviewing the evolution of steam models this paper presents a model which advances the state-of-the-art of steam modelling. The main advance presented in this paper is modelling the effects of the various flow regimens that occur during steam injection. The paper describes the formulation of a two-phase downward vertical flow pressure drop model which is not limited by the ''no-slip'' homogeneous flow assumptions in most previously published models. By using different correlations for mist, bubble, and slug flow, improved pressure drop calculations result, which in turn improve temperature predictions. The paper describes how the model handles temperature predictions differently in the single and two-phase steam flow situations. The paper also describes special features in the model to account for layered soil properties, soil dry out, cyclic injection, coupling heat losses, and reflux boiling in wet annuli. Two examples problems are presented which illustrate some of these features.

Galate, J.W.; Mitchell, R.F.

1985-03-01T23:59:59.000Z

75

A Reduced-Order Model of a Chevron Plate Heat Exchanger for Rapid Thermal Management by Using Thermo-Chemical Energy Storage  

E-Print Network (OSTI)

The heat flux demands for electronics cooling applications are quickly approaching the limits of conventional thermal management systems. To meet the demand of next generation electronics, a means for rejecting high heat fluxes at low temperatures in a compact system is an urgent need. To answer this challenge, in this work a gasketed chevron plate heat exchanger in conjunction with a slurry consisting of highly endothermic solid ammonium carbamate and a heat transfer fluid. A reduced-order 1-dimensional model was developed and used to solve the coupled equations for heat, mass, and momentum transfer. The feasibility of this chosen design for satisfying the heat rejection load of 2kW was also explored in this study. Also, a decomposition reaction using acetic acid and sodium bicarbonate was conducted in a plate heat exchanger (to simulate a configuration similar to the ammonium carbamate reactions). This enabled the experimental validation of the numerical predictions for the momentum transfer correlations used in this study (which in turn, are closely tied to both the heat transfer correlations and chemical kinetics models). These experiments also reveal important parameters of interest that are required for the reactor design. A numerical model was developed in this study and applied for estimating the reactor size required for achieving a power rating of 2 kW. It was found that this goal could be achieved with a plate heat exchanger weighing less than 70 kg (~100 lbs) and occupying a volume of 29 L (which is roughly the size of a typical desktop printer). Investigation of the hydrodynamic phenomena using flow visualization studies showed that the flow patterns were similar to those described in previous studies. This justified the adaptation of empirical correlations involving two-phase multipliers that were developed for air-water two-phase flows. High-speed video confirmed the absence of heterogeneous flow patterns and the prevalence of bubbly flow with bubble sizes typically less than 0.5 mm, which justifies the use of homogenous flow based correlations for vigorous gas-producing reactions inside a plate heat exchanger. Absolute pressure measurements - performed for experimental validation studies - indicate a significant rise in back pressure that are observed to be several times greater than the theoretically estimated values of frictional and gravitational pressure losses. The predictions from the numerical model were found to be consistent with the experimental measurements, with an average absolute error of ~26%

Niedbalski, Nicholas

2012-08-01T23:59:59.000Z

76

Rapid Metal Heating: Reducing Energy Consumption and Increasing Productivity in the Thermal Processing of Metals  

Science Conference Proceedings (OSTI)

Energy intensive manufacturing operations, such as iron and steel production, forging, and heat treating, are attempting to increase productivity while decreasing energy consumption.

2000-05-08T23:59:59.000Z

77

Visualization of flow boiling in an annular heat exchanger under reduced gravity conditions.  

E-Print Network (OSTI)

??This work examines the effects of gravitational acceleration on the flow boiling process. A test facility focusing on an annular heat exchanger was designed, built… (more)

Westheimer, David Thomas

2012-01-01T23:59:59.000Z

78

Method for cutting steam heat losses during cyclic steam injection of wells. Final report  

SciTech Connect

Heavy Oil is abundant in California. It is a very viscous fluid, which must be thinned in order to flow from wells at economical rates. The best method of oil viscosity reduction is by cyclic steam injection into the oil-containing rock formations. Making steam in conventional generators fueled with Natural Gas is, however, a costly process. The main objective of this Project is to reduce the cost of the required steam, per Barrel of Oil produced. This is made possible by a combination of Patented new technologies with several known methods. The best known method for increasing the production rate from oil wells is to use horizontal drainholes, which provide a much greater flow area from the oil zone into the well. A recent statistic based on 344 horizontal wells in 21 Canadian Oil fields containing Heavy Oil shows that these are, on the average six times more prolific than vertical wells. The cost of horizontal wells, however, is generally two to three times that of a vertical well, in the same field, so our second goal is to reduce the net cost of horizontal wells by connecting two of them to the same vertical casing, well head and pumping system. With such a well configuration, it is possible to get two horizontal wells for the price of about one and a half times the price of a single vertical well.

Gondouin, M.

1995-12-01T23:59:59.000Z

79

Technical Potential of Solar Water Heating to Reduce Fossil Fuel Use and Greenhouse Gas Emissions in the United States  

DOE Green Energy (OSTI)

Use of solar water heating (SWH) in the United States grew significantly in the late 1970s and early 1980s, as a result of increasing energy prices and generous tax credits. Since 1985, however, expiration of federal tax credits and decreased energy prices have virtually eliminated the U.S. market for SWH. More recently, increases in energy prices, concerns regarding emissions of greenhouse gases, and improvements in SWH systems have created new interest in the potential of this technology. SWH, which uses the sun to heat water directly or via a heat-transfer fluid in a collector, may be particularly important in its ability to reduce natural gas use. Dependence on natural gas as an energy resource in the United States has significantly increased in the past decade, along with increased prices, price volatility, and concerns about sustainability and security of supply. One of the readily deployable technologies available to decrease use of natural gas is solar water heating. This report provides an overview of the technical potential of solar water heating to reduce fossil fuel consumption and associated greenhouse gas emissions in U.S. residential and commercial buildings.

Denholm, P.

2007-03-01T23:59:59.000Z

80

Method for cutting steam heat losses during cyclic steam injection of wells. Second quarterly report  

SciTech Connect

The Midway-Sunset Field (CA) is the largest Heavy Oil field in California and steam injection methods have been successfully used for more than 30 years to produce the Heavy Oil from many of its unconsolidated sand reservoirs. In partnership with another DOE/ERIP grantee, our Company has acquired an 80 ac. lease in the SE part of this field, in order to demonstrate our respective technologies in the Monarch sand, of Miocene Age, which is one of the reservoirs targeted by the DOE Class 3 Oil Program. This reservoir contains a 13 API oil, which has a much higher market value, as a Refinery Feedstock, than the 5 to 8 API Vaca Tar, used only as road paving material. This makes it easier to justify the required investment in a vertical well equipped with two horizontal drainholes. The economic viability of such a project is likely to be enhanced if Congress approves the export to Japan of a portion of the 27 API (1% Sulfur) AK North Slope oil, which currently is landed in California in preference to lighter and sweeter Far East imported crudes. This is a major cause of the depressed prices for California Heavy Oil in local refineries, which have reduced the economic viability of all EOR methods, including steam injection, in California. Two proposals, for a Near-Term (3 y.) and for a Mid-Term (6 y.) project respectively, were jointly submitted to the DOE for Field Demonstration of the Partners` new technologies under the DOE Class 3 Oil Program. The previous design of a special casing joint for the Oxnard field well was reviewed and adapted to the use of existing Downhole Hardware components from three suppliers, instead of one. The cost of drilling and completion of a well equipped with two horizontal drainholes was re-evaluated for the conditions prevailing in the Midway Sunset field, which are more favorable than in the Oxnard field, leading to considerable reductions in drilling rig time and cost.

Not Available

1994-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduce heat loss" 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

Economic and environmental benefits of reducing standby power loss in DVD/VCD players and copiers in China  

E-Print Network (OSTI)

growth of standby energy consumption due to these products ?and reduce standby energy consumption (US EPA, 2004, IEA,However, standby energy consumption is still a new concept

Lin, Jiang; Li, Tienan; Li, Aizhen; Zhang, Guoqing

2004-01-01T23:59:59.000Z

82

Effects of plumbing attachments on heat losses from solar domestic hot water storage tanks. Final report, Part 2  

DOE Green Energy (OSTI)

The Solar Rating and Certification Corporation (SRCC) has established a standardized methodology for determining the performance rating of the Solar Domestic Hot Water (SDHW) systems it certifies under OG-300. Measured performance data for the solar collector component(s) of the system are used along with numerical models for the balance of the system to calculate the system`s thermal performance under a standard set of rating conditions. SRCC uses TRNSYS to model each of the components that comprise the system. The majority of the SRCC certified systems include a thermal storage tank with an auxiliary electrical heater. The most common being a conventional fifty gallon electric tank water heater. Presently, the thermal losses from these tanks are calculated using Q = U {center_dot} A {center_dot} {Delta}T. Unfortunately, this generalized formula does not adequately address temperature stratification both within the tank as well as in the ambient air surrounding the tank, non-uniform insulation jacket, thermal siphoning in the fluid lines attached to the tank, and plumbing fittings attached to the tank. This study is intended to address only that part of the problem that deals with the plumbing fittings attached to the tank. Heat losses from a storage tank and its plumbing fittings involve three different operating modes: charging, discharging and standby. In the charging mode, the tank receives energy from the solar collector. In the discharge mode, water flows from the storage tank through the distribution pipes to the faucets and cold city water enters the tank. In the standby mode, there is no forced water flow into or out of the tank. In this experimental study, only the standby mode was considered.

Song, J.; Wood, B.D. [Univ. of Nevada, Reno, NV (United States); Ji, L.J. [Arizona State Univ., Tempe, AZ (United States)

1998-03-01T23:59:59.000Z

83

Evidence for ultra-fast heating in intense-laser irradiated reduced-mass targets  

Science Conference Proceedings (OSTI)

We report on an experiment irradiating individual argon droplets of 20 {mu}m diameter with laser pulses of several Joule energy at intensities of 10{sup 19} W/cm{sup 2}. K-shell emission spectroscopy was employed to determine the hot electron energy fraction and the time-integrated charge-state distribution. Spectral fitting indicates that bulk temperatures up to 160 eV are reached. Modelling of the hot-electron relaxation and generation of K-shell emission with collisional hot-electron stopping only is incompatible with the experimental results, and the data suggest an additional ultra-fast (sub-ps) heating contribution. For example, including resistive heating in the modelling yields a much better agreement with the observed final bulk temperature and qualitatively reproduces the observed charge state distribution.

Neumayer, P.; Gumberidze, A.; Hochhaus, D. C. [ExtreMe Matter Institute EMMI and Research Division, GSI Helmholtzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Frankfurt Institute for Advanced Studies FIAS, 60438 Frankfurt am Main (Germany); Aurand, B.; Stoehlker, T. [Helmholtzzentrum fuer Schwerionenforschung GSI, 64291 Darmstadt (Germany); Helmholtz Institute Jena, 07743 Jena (Germany); Costa Fraga, R. A.; Kalinin, A. [Institut fuer Kernphysik, J. W. Goethe University Frankfurt, 60438 Frankfurt am Main (Germany); Ecker, B. [Johannes Gutenberg University Mainz, 55099 Mainz (Germany); Helmholtz Institute Jena, 07743 Jena (Germany); Grisenti, R. E. [Institut fuer Kernphysik, J. W. Goethe University Frankfurt, 60438 Frankfurt am Main (Germany); Helmholtzzentrum fuer Schwerionenforschung GSI, 64291 Darmstadt (Germany); Kaluza, M. C. [Helmholtz Institute Jena, 07743 Jena (Germany); IOQ Institute of Optics and Quantum Electronics, University of Jena (Germany); Kuehl, T. [Johannes Gutenberg University Mainz, 55099 Mainz (Germany); Helmholtzzentrum fuer Schwerionenforschung GSI, 64291 Darmstadt (Germany); Helmholtz Institute Jena, 07743 Jena (Germany); Polz, J. [IOQ Institute of Optics and Quantum Electronics, University of Jena (Germany); Reuschl, R. [ExtreMe Matter Institute EMMI and Research Division, GSI Helmholtzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Winters, D.; Winters, N.; Yin, Z. [Helmholtzzentrum fuer Schwerionenforschung GSI, 64291 Darmstadt (Germany)

2012-12-15T23:59:59.000Z

84

Reduced heat flow in light water (H2O) due to heavy water (D2O)  

E-Print Network (OSTI)

The flow of heat, from top to bottom, in a column of light water can be decreased by over 1000% with the addition of heavy water. A column of light water cools from 25 C to 0 C in 11 hours, however, with the addition of heavy water it takes more than 100 hours. There is a concentration dependence where the cooling time increases as the concentration of added (D2O) increases, with a near maximum being reached with as little as 2% of (D2O) added. This phenomenon will not occur if the water is mixed after the heavy water is added.

William R. Gorman; James D. Brownridge

2008-09-04T23:59:59.000Z

85

Hot Thermal Storage/Selective Energy System Reduces Electric Demand for Space Cooling As Well As Heating in Commercial Application  

E-Print Network (OSTI)

Based on an experimental residential retrofit incorporating thermal storage, and extensive subsequent modeling, a commercial design was developed and implemented to use hot thermal storage to significantly reduce electric demand and utility energy costs during the cooling season as well as the heating season. To achieve air conditioning savings, the system separates dehumidification from sensible cooling; dehumidifies by desiccant absorption, using heat from storage to dry the desiccant; and then cools at an elevated temperature improving overall system efficiency. Efficient heat for desiccant regeneration is provided by a selective-energy system coupled with thermal storage. The selective-energy system incorporates diesel cogeneration, solar energy and off-peak electric resistance heating. Estimated energy and first cost savings, as compared with an all-electric VAV HVAC system, are: 30 to 50% in ductwork size and cost; 30% in fan energy; 25% in air handling equipment; 20 to 40% in utility energy for refrigeration; 10 to 20% in refrigeration equipment; and space savings due to smaller ductwork and equipment.

Meckler, G.

1985-01-01T23:59:59.000Z

86

An Evaluation of the Placement of the Placement of Radiant Barriers on their Effectiveness in Reducing Heat Transfer in Attics  

E-Print Network (OSTI)

Experimental tests were conducted to measure the influence of radiant barriers and the effect of the radiant barrier location on attic heat transfer. All the tests were conducted in an attic simulator at a steady state. The heat flux through the attic floor was measured at two different roof deck temperatures (120°F and 140°F). The temperature distribution within the base fibrous insulation was also measured. Three different solid kraft laminates with aluminum foil backing were tested. There was a 34 percent reduction (sample A) in heat flux through the ceiling for the case where the radiant barrier was placed 6 inches below the roof deck in addition to the base fibrous insulation (R-11), with the roof deck at 140 F. The reduction for the same sample with the radiant barrier placed on the studs of the attic floor was 46 percent. For all the three samples, the heat flux through the attic floor was reduced when the radiant barrier was placed on the attic floor studs.

Katipamula, S.; O'Neal, D.

1986-01-01T23:59:59.000Z

87

IMPLEMENTING HEAT SEALED BAG RELIEF & HYDROGEN & METANE TESTING TO REDUCE THE NEED TO REPACK HANFORD TRANSURANIC (TRU) WASTE  

DOE Green Energy (OSTI)

The Department of Energy's site at Hanford has a significant quantity of drums containing heat-sealed bags that required repackaging under previous revisions of the TRUPACT-II Authorized Methods for Payload Control (TRAMPAC) before being shipped to the Waste Isolation Pilot Plant (WIPP). Since glovebox repackaging is the most rate-limiting and resource-intensive step for accelerating Hanford waste certification, a cooperative effort between Hanford's TRU Program and the WIPP site significantly reduced the number of drums requiring repackaging. More specifically, recent changes to the TRAMPAC (Revision 19C), allow relief for heat-sealed bags having more than 390 square inches of surface area. This relief is based on data provided by Hanford on typical Hanford heat-sealed bags, but can be applied to other sites generating transuranic waste that have waste packaged in heat-sealed bags. The paper provides data on the number of drums affected, the attendant cost savings, and the time saved. Hanford also has a significant quantity of high-gram drums with multiple layers of confinement including heat-scaled bags. These higher-gram drums are unlikely to meet the decay-heat limits required for analytical category certification under the TRAMPAC. The combination of high-gram drums and accelerated reprocessing/shipping make it even more difficult to meet the decay-heat limits because of necessary aging requirements associated with matrix depletion. Hydrogen/methane sampling of headspace gases can be used to certify waste that does not meet decay-heat limits of the more restrictive analytical category using the test category. The number of drums that can be qualified using the test category is maximized by assuring that the detection limit for hydrogen and methane is as low as possible. Sites desiring to ship higher-gram drums must understand the advantages of using hydrogen/methane sampling and shipping under the test category. Headspace gas sampling, as specified by the WIPP Waste Analysis Plan, provides the sample necessary for hydrogen/methane analysis. Most Hanford drums are not equipped with a filter through which a headspace gas sample can be obtained. A pneumatic system is now used to insert ''dart'' filters. The filters were developed by the vendor and approved for WIPP certification at the request of the Hanford Site. The same pneumatic system is used to install septum-type sample ports to allow the headspace to be sampled. Together, these steps allow the Hanford Site to avoid repackaging a large percentage of drums, and thus accelerate certification of waste destined for WIPP.

MCDONALD, K.M.

2005-01-20T23:59:59.000Z

88

Generation of a Parabolic Trough Collector Efficiency Curve from Separate Measurements of Outdoor Optical Efficiency and Indoor Receiver Heat Loss: Preprint  

DOE Green Energy (OSTI)

The overall efficiency of a parabolic trough collector is a function of both the fraction of direct normal radiation absorbed by the receiver (the optical efficiency) and the heat lost to the environment when the receiver is at operating temperature. The overall efficiency can be determined by testing the collector under actual operating conditions or by separately measuring these two components. This paper describes how outdoor measurement of the optical efficiency is combined with laboratory measurements of receiver heat loss to obtain an overall efficiency curve. Further, it presents a new way to plot efficiency that is more robust over a range of receiver operating temperatures.

Kutscher, C.; Burkholder, F.; Stynes, K.

2010-10-01T23:59:59.000Z

89

Refinery Waste Heat Ammonia Absorption Refrigeration Plant (WHAARP) Recovers LPG's and Gasoline, Saves Energy, and Reduces Air Pollution  

E-Print Network (OSTI)

A first-of-its-kind Waste Heat Ammonia Absorption Refrigeration Plant (WHAARP™) was installed by Planetec Utility Services Co., Inc. in partnership with Energy Concepts Co. at Ultramar Diamond Shamrock's 30,000 barrel per day refinery in Denver, Colorado. The refrigeration unit is designed to provide refrigeration for two process units at the refinery while utilizing waste heat as the energy source. The added refrigeration capacity benefits the refinery by recovering salable products, debottlenecking process units, avoiding additional electrical demand, and reducing the refinery Energy Intensity Index. In addition, the WHAARP unit lowers air pollutant emissions by reducing excess fuel gas that is combusted in the refinery flare. A comprehensive utility and process efficiency Master Plan developed for the Denver refinery by Planetec provided the necessary platform for implementing this distinctive project. The $2.3 million WHAARP system was paid for in part by a $760,000 grant from the U.S. Department of Energy, as part of their "Industry of the Future Program". Total combined benefits are projected to be approximately $1 million/year with a 1.6 year simple payback including the grant funding.

Brant, B.; Brueske, S.; Erickson, D.; Papar, R.

1998-04-01T23:59:59.000Z

90

SOLAR HEATING OF TANK BOTTOMS Application of Solar Heating to Asphaltic and Parrafinic Oils Reducing Fuel Costs and Greenhouse Gases Due to Use of Natural Gas and Propane  

DOE Green Energy (OSTI)

The sale of crude oil requires that the crude meet product specifications for BS&W, temperature, pour point and API gravity. The physical characteristics of the crude such as pour point and viscosity effect the efficient loading, transport, and unloading of the crude oil. In many cases, the crude oil has either a very high paraffin content or asphalt content which will require either hot oiling or the addition of diluents to the crude oil to reduce the viscosity and the pour point of the oil allowing the crude oil to be readily loaded on to the transport. Marginal wells are significantly impacted by the cost of preheating the oil to an appropriate temperature to allow for ease of transport. Highly paraffinic and asphaltic oils exist throughout the D-J basin and generally require pretreatment during cold months prior to sales. The current study addresses the use of solar energy to heat tank bottoms and improves the overall efficiency and operational reliability of stripper wells.

Eugene A. Fritzler

2005-09-01T23:59:59.000Z

91

A novel isolation curtain to reduce turbine ingress heating and an advanced model for honeycomb labyrinth seals  

E-Print Network (OSTI)

A combination of 3-D and 2-D computational fluid dynamics (CFD) modeling as well as experimental testing of the labyrinth seal with hexagonal honeycomb cells on the stator wall was performed. For the 3-D and 2-D CFD models, the hexagonal honeycomb structure was modeled using the concept of the baffle (zero-thickness wall) and the simplified 2-D fin, respectively. The 3-D model showed that even a small axial change of the tooth (or honeycomb wall) location, or a small circumferential change of the honeycomb wall location significantly affected the flow patterns and leakage characteristics especially for small tooth tip clearance. Also, the local details of the flow field were investigated. The seven basic procedural steps to develop a 2-D axisymmetric honeycomb labyrinth seal leakage model were shown. Clearly demonstrated for varying test conditions was the 2-D model capability to predict the 3-D honeycomb labyrinth flow that had been measured at different operating conditions from that used in developing the 2-D model. Specifically, the 2-D model showed very close agreement with measurements. In addition, the 2-D model greatly reduced the computer resource requirement needed to obtain a solution of the 3-D honeycomb labyrinth seal leakage. The novel and advanced strategy to reduce the turbine ingress heating, and thus the coolant requirement, by injecting a Â?coolant isolation curtainÂ? was developed numerically using a 3-D CFD model. The coolant isolation curtain was applied under the nozzle guide vane platform for the forward cavity of a turbine stage. Specifically, the isolation curtain serves to isolate the hot mainstream gas from the turbine outer region. The effect of the geometry change, the outer cavity axial gap clearance, the circumferential location of the injection curtain slot and the injection fluid angle on the ingress heating was investigated. Adding the chamfer to the baseline design gave a similar or higher maximum temperature T* max than did the baseline design without chamfer, but implementation of the injection curtain slot reduced substantially T* max of the outer region. In addition, a more desirable uniform adiabatic wall temperature distribution along the outer rotor and stator surfaces was observed due to the presence of the isolation curtain.

Choi, Dong Chun

2005-05-01T23:59:59.000Z

92

Developing a Predation Index and Evaluating Ways to Reduce Salmonid Losses to Predation in the Columbia River Basin, Final Report August 1988-September 1990.  

DOE Green Energy (OSTI)

We report our results of studies to develop a predation index and evaluate ways to reduce juvenile salmonid losses to predation in the Columbia River Basin. Study objectives of each were: develop an index to estimate predation losses of juvenile salmonids (Oncorhynchus spp) in reservoirs throughout the Columbia River Basin, describe the relationships among predator-caused mortality of juvenile salmonids and physical and biological variables, examine the feasibility of developing bounty, commercial or recreational fisheries on northern squawfish (Ptychocheilus oregonensis) and develop a plan to evaluate the efficacy of predator control fisheries; determine the economic feasibility of developing bounty and commercial fisheries for northern squawfish, assist ODFW with evaluating the economic feasibility of recreational fisheries for northern squawfish and assess the economic feasibility of utilizing northern squawfish, carp (Cyprinus carpio) and suckers (Castostomus spp) in multispecies fisheries; evaluate commercial technology of various fishing methods for harvesting northern squawfish in Columbia River reservoirs and field test the effectiveness of selected harvesting systems, holding facilities and transportation systems; and modify the existing Columbia River Ecosystem Model (CREM) to include processes necessary to evaluate effects of removing northern squawfish on their population size structure and abundance, document the ecological processes, mathematical equations and computer (FORTRAN) programming of the revised version of CREM and conduct systematic analyses of various predator removal scenarios, using revised CREM to generate the simulations. Individual reports are indexed separately.

Nigro, Anthony A.

1990-12-01T23:59:59.000Z

93

The study of aluminum loss and consequent phase transformation in heat-treated acid-leached kaolin  

Science Conference Proceedings (OSTI)

This study investigates the effect of Al leaching during Fe removal from kaolin to mullite. Heat-treated kaolin was obtained by heating natural kaolin at 400, 500, 600, 700, 800 and 900 deg. C. The heat-treated kaolin was then leached at 100 deg. C with 4 M, 3 M, 2 M, 1 M, 0.2 M solution of H{sub 2}SO{sub 4} and 0.2 M solution of oxalic acid. The dried samples were sintered to 1300 deg. C for 4 h at a heating rate of 10 deg. C min{sup -1}. X-ray diffractometry and differential thermal analysis were used to study the phase transformation of kaolin to mullite. It was found that 700 deg. C is the optimum preheat-treatment temperature to leach out Fe and also Al for both types of the acids used. The majority of the 4 M sulfuric acid-treated kaolins formed the cristobalite phase when sintered. On the other hand, 1 M, 0.2 M sulfuric acid and 0.2 M oxalic acid leached heat-treated kaolin formed mullite and quartz phase after sintering. - Research Highlights: {yields} Preheat-treatment of kaolin improves the leachability of unwanted iron. {yields} The optimum preheat-treatment temperature is 700 deg. C. {yields} Sintered 4 M sulfuric acid-treated kaolin majorly formed the cristobalite phase. {yields} Sintered 0.2 M oxalic acid-treated kaolin formed lesser amorphous silicate phase.

Foo, Choo Thye [Malaysian Nuclear Agency (Nuclear Malaysia) Bangi, Selangor (Malaysia); Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology, University Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Mahmood, Che Seman [Malaysian Nuclear Agency (Nuclear Malaysia) Bangi, Selangor (Malaysia); Mohd Salleh, Mohamad Amran, E-mail: asalleh@eng.upm.edu.my [Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology, University Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Chemical Engineering Department, University Putra Malaysia, 43400 Serdang, Selangor (Malaysia)

2011-04-15T23:59:59.000Z

94

Alternatives for reducing hot-water bills  

DOE Green Energy (OSTI)

A two stage approach to reducing residential water heating bills is described. In Stage I, simple conservation measures were included to reduce the daily hot water energy consumption and the energy losses from the water tank. Once these savings are achieved, Stage II considers more costly options for further reducing the water heating bill. Four alternatives are considered in Stage II: gas water heaters; solar water heaters (two types); heat pump water heaters; and heat recovery from a heat pump or air conditioner. To account for variations within the MASEC region, information on water heating in Rapid City, Minneapolis, Chicago, Detroit, and Kansas City is presented in detail. Information on geography, major population centers, fuel prices, climate, and state solar incentives is covered. (MCW)

Bennington, G.E.; Spewak, P.C.

1981-06-01T23:59:59.000Z

95

Vehicle Technologies Office: Parasitic Loss Reduction  

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

Parasitic Loss Reduction Parasitic Loss Reduction Heavy vehicles lose a tremendous amount of energy to wind resistance and drag, braking, and rolling resistance. Such non-engine losses can account for an approximate 45% decrease in efficiency. Other sources of energy loss include: friction and wear in the power train, thermal (heat) loads, operation of auxiliary loads (air conditioning, heaters, refrigeration, etc.), and engine idling. The parasitic loss activity identifies methodologies that may reduce energy losses, and tests those in the laboratory. Promising technologies are then prototyped and tested onboard heavy vehicles. Once validated, technologies must be tested on-road to obtain durability, reliability, and life-cycle cost data for the developmental component and/or design strategy.

96

Minimizing Energy Losses in Ducts | Department of Energy  

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

Minimizing Energy Losses in Ducts Minimizing Energy Losses in Ducts Minimizing Energy Losses in Ducts June 24, 2012 - 5:45pm Addthis Placing ductwork in conditioned space can help reduce energy losses. | Photo courtesy of ©iStockphoto/SimplyCreativePhotography Placing ductwork in conditioned space can help reduce energy losses. | Photo courtesy of ©iStockphoto/SimplyCreativePhotography In new home construction or in retrofits, proper duct system design is critical. In recent years, energy-saving designs have sought to include ducts and heating systems in the conditioned space. Many existing duct systems lose a lot of energy from leakage and poor insulation, but you can reduce that loss by sealing and insulating your ducts. Existing ducts may also be blocked or may require simple upgrades.

97

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

98

NGNP Process Heat Utilization: Liquid Metal Phase Change Heat Exchanger  

DOE Green Energy (OSTI)

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

Piyush Sabharwall; Mike Patterson; Vivek Utgikar; Fred Gunnerson

2008-09-01T23:59:59.000Z

99

A REDUCED ORDER MODEL OF TWO-PHASE FLOW, HEAT TRANSFER AND COMBUSTION IN CIRCULATING FLUIDIZED-BEDS  

SciTech Connect

This report summarizes the objectives, tasks and accomplishments of the second year of this research project. The report presents the following program deliverables: (1) visualization tools for reconstructing simulated data; (2) algorithms for reducing the partial differential equations to ordinary differential equations; and (3) visualization tools for Galerkin ordinary differential equations.

Paul Cizmas

2002-12-01T23:59:59.000Z

100

Improvement to Air2Air Technology to Reduce Fresh-Water Evaporative Cooling Loss at Coal-Based Thermoelectric Power Plants  

Science Conference Proceedings (OSTI)

This program was undertaken to enhance the manufacturability, constructability, and cost of the Air2Air{TM} Water Conservation and Plume Abatement Cooling Tower, giving a validated cost basis and capability. Air2Air{TM} water conservation technology recovers a portion of the traditional cooling tower evaporate. The Condensing Module provides an air-to-air heat exchanger above the wet fill media, extracting the heat from the hot saturated moist air leaving in the cooling tower and condensing water. The rate of evaporate water recovery is typically 10% - 25% annually, depending on the cooling tower location (climate). This program improved the efficiency and cost of the Air2Air{TM} Water Conservation Cooling Tower capability, and led to the first commercial sale of the product, as described.

Ken Mortensen

2011-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "reduce heat loss" 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

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

E-Print Network (OSTI)

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

Banerjee, Sibashis Sanatkumar

1994-01-01T23:59:59.000Z

102

A REDUCED ORDER MODEL OF TWO-PHASE FLOW, HEAT TRANSFER AND COMBUSTION IN CIRCULATING FLUIDIZED-BEDS  

SciTech Connect

The report summarizes the objectives, tasks and accomplishments of this research project. The report presents the following program deliverables: (1) database generation using MFIX code, (2) development and implementation of an algorithm to calculate the proper orthogonal decomposition (POD) basis functions, (3) visualization tools for reconstructing simulated data, (4) algorithms for reducing the partial differential equations to ordinary differential equations, (5) visualization tools for Galerkin ordinary differential equations, (6) verification and validation of the code by comparing POD and conventional solution results, and (7) development of POD strategy for best energy cut-off values.

Paul Cizmas

2003-12-01T23:59:59.000Z

103

Heat Transfer Characteristics of a Generalized Divided Flow Heat Exchanger  

E-Print Network (OSTI)

The concept of a "Divided-flow" heat exchanger is generalized by locating the shell inlet (or outlet) nozzle off-center such that the two shell sub-streams are unequal and traverse unequal flow paths. The governing equations for heat transfer in such an exchanger are derived and solved leading to an optimization problem. In this problem, the optimal subdivision of heat transfer surface to minimize required overall heat transfer surface, under certain restricted conditions, is sought. It is shown that the off-center nozzle location can be selected judiciously so as to maintain (or even improve heat transfer) while reducing the gross shellside pressure loss. Thus, the pumping costs are minimized without sacrificing heat transfer.

Singh, K. P.

1979-01-01T23:59:59.000Z

104

Water heater heat reclaimer  

SciTech Connect

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

Wie, C.T.

1983-08-09T23:59:59.000Z

105

System for reducing heat losses from indoor swimming pools by use of automatic covers. Final report, October 1, 1993--September 30, 1995  

SciTech Connect

This final report is an account of the principal activities of Lof Energy Systems, Inc. in a two-year project funded by the Energy Related Inventions Program (ERIP) of the U.S. Department of Energy. The primary objective has been the development of a fully practical and economical system for saving energy in indoor swimming pools by use of motorized covers. The goal is wide-spread use of a fully developed product, in institutional swimming pools. Four major tasks, depicted in the accompanying Performance Schedule, have been completed, and one other has been initiated and its completion committed. Principal accomplishments have been the selection and improvement of cover materials and designs, lengthening and strengthening of reels and improvements in motorized components and their control, design and installation of pool covers in full scale demonstration and evaluation of fully developed commercial system, preparation and dissemination of manuals and reports, finalization of arrangements for Underwriters Laboratory certification of products, and final report preparation and submission. Of greatest significance has been the successful demonstration of the fully developed system and the verification and reporting by an energy consultant of the large savings resulting from pool cover use. Probably the best evidence of success of the DOE-ERIP project in advancing this invention to a commercial stage is its acceptance for sale by the Lincoln Equipment Company, a national distributor of swimming pool supplies and equipment. A copy of the relevant page in the Lincoln catalog is included in this report as Annex A. Representatives of that company now offer Tof motorized pool cover systems to their pool owner customers. In addition to the plans for securing UL certification the company expects to continue making design improvements that can increase system reliability, durability, and cost-effectiveness.

1996-01-01T23:59:59.000Z

106

The Confusing Allure of Combined Heat and Power: The Financial Attraction and Management Challenge of Reducing Energy Spend and Resulting Carbon Emissions Through Onsite Power Generation  

E-Print Network (OSTI)

Sixty-one percent of global executives surveyed by McKinsey & Co. (in 2008) expect the issues associated with climate change to boost profits—if managed well. What these executives recognize is that new regulations, higher energy costs, and increased scrutiny by private gate-keepers (such as Wal-Mart) offer an opportunity to identify and implement more efficient practices in commercial and industrial environments. One of the most impactful solutions for the industrial sector—from the perspective of reducing energy spending and energy-related carbon emissions—is combined heat and power ("CHP"), sometimes referred to as cogeneration. However, the results of CHP deployment to date have been mixed—largely because companies do not fully appreciate the challenges of maintaining and operating a CHP system, optimizing its performance, and taking full advantage of the many benefits it offers. Despite these challenges, the slogan for CHP should perhaps be: "CHP, now more than ever".

Davis, R.

2009-05-01T23:59:59.000Z

107

A study of the utility of heat collectors in reducing the response time of automatic fire sprinklers located in production modules of Building 707  

Science Conference Proceedings (OSTI)

Several of the ten production Modules in Building 707 at the Department of Energy Rocky Flats Plant recently underwent an alteration which can adversely affect the performance of the installed automatic fire sprinkler systems. The Modules have an approximate floor to ceiling height of 17.5 ft. The alterations involved removing the drop ceilings in the Modules which had been at a height of 12 ft above the floor. The sprinkler systems were originally installed with the sprinkler heads located below the drop ceiling in accordance with the nationally recognized NFPA 13, Standard for the Installation of Automatic Sprinkler Systems. The ceiling removal affects the sprinkler`s response time and also violates NFPA 13. The scope of this study included evaluation of the feasibility of utilizing heat collectors to reduce the delays in sprinkler response created by the removal of the drop ceilings. The study also includes evaluation of substituting quick response sprinklers for the standard sprinklers currently in place, in combination with a heat collector.

Shanley, J.H. Jr.; Budnick, E.K. Jr. [Hughes Associates, Inc., Wheaton, MD (United States)

1990-01-01T23:59:59.000Z

108

Study on the use of TiO{sub 2} passivation layer to reduce recombination losses in dye sensitized solar cells  

Science Conference Proceedings (OSTI)

A lot of research on various aspects of dye solar cells (DSC) has been carried out in order to improve efficiency. This paper analyzes the utilization of TiO{sub 2} passivation layers of different thicknesses by improving the electron transport properties. Four different thicknesses of passivation layers namely 10, 20, 50 and 100 nm were deposited onto the working electrode using r.f sputtering. The electrodes were assembled into TiO{sub 2} based DSC with active area of 1 cm{sup 2}. The solar performance was investigated using 100 mW/cm{sup 2} of AM 1.5 simulated sunlight from solar simulator. The kinetics of the solar cells was investigated using Electrochemical Impedance Spectroscopy (EIS) measurement and the spectral response was measured using Incident Photon to Electron Conversion (IPCE) measurement system. The highest efficiency was found for DSC with 20 nm passivation layer. DSCs with the passivation layer have open circuit voltage, V{sub OC} increased by 57 mV, their current density, J{sub SC} increased by 0.774 mA cm{sup -2} compared to the one without the passivation layer. The quantum efficiency of the 20 nm passivation layer is the highest, peaking at the wavelength of 534 nm, resulting in the highest performance. All DSCs with the passivation layer recorded higher ratio of R{sub BR}/R{sub T} where R{sub T} is the diffusion resistance of the TiO{sub 2} particles in the mesoscopic layer and R{sub BR} is the recombination resistance of the electron to the electrolyte. This implies that the recombination of the electrolyte I{sup -}{sub 3}/3I{sup -} couple at the substrate/electrolyte interface has been effectively reduced resulting in an enhanced efficiency.

Eskander bin Samsudin, Adel; Mohamed, Norani Muti; Nayan, Nafarizal; Ali, Riyaz Ahmad Mohamed; Shariffuddin, Sharifah Amira Amir; Omar, Salwa [Electrical and Electronics Department, 31750, Tronoh, Universiti Teknologi PETRONAS (Malaysia); Fundamental and Applied Sciences Department, 31750, Tronoh, Universiti Teknologi PETRONAS (Malaysia); Electronic Engineering Department, Electrical and Electronic Engineering Faculty, Universiti Tun Hussein Onn Malaysia (UTHM) (Malaysia)

2012-09-26T23:59:59.000Z

109

Using Cool Roofs to Reduce Energy Use, Greenhouse Gas Emissions, and Urban Heat-island Effects: Findings from an India Experiment  

Science Conference Proceedings (OSTI)

Cool roofs, cool pavements, and urban vegetation reduce energy use in buildings, lower local air pollutant concentrations, and decrease greenhouse gas emissions from urban areas. This report summarizes the results of a detailed monitoring project in India and related simulations of meteorology and air quality in three developing countries. The field results quantified direct energy savings from installation of cool roofs on individual commercial buildings. The measured annual energy savings potential from roof-whitening of previously black roofs ranged from 20-22 kWh/m2 of roof area, corresponding to an air-conditioning energy use reduction of 14-26% in commercial buildings. The study estimated that typical annual savings of 13-14 kWh/m2 of roof area could be achieved by applying white coating to uncoated concrete roofs on commercial buildings in the Metropolitan Hyderabad region, corresponding to cooling energy savings of 10-19%. With the assumption of an annual increase of 100,000 square meters of new roof construction for the next 10 years in the Metropolitan Hyderabad region, the annual cooling energy savings due to whitening concrete roof would be 13-14 GWh of electricity in year ten alone, with cumulative 10-year cooling energy savings of 73-79 GWh for the region. The estimated savings for the entire country would be at least 10 times the savings in Hyderabad, i.e., more than 730-790 GWh. We estimated that annual direct CO2 reduction associated with reduced energy use would be 11-12 kg CO2/m2 of flat concrete roof area whitened, and the cumulative 10-year CO2 reduction would be approximately 0.60-0.65 million tons in India. With the price of electricity estimated at seven Rupees per kWh, the annual electricity savings on air-conditioning would be approximately 93-101 Rupees per m2 of roof. This would translate into annual national savings of approximately one billion Rupees in year ten, and cumulative 10-year savings of over five billion Rupees for cooling energy in India. Meteorological simulations in this study indicated that a reduction of 2C in air temperature in the Hyderabad area would be likely if a combination of increased surface albedo and vegetative cover are used as urban heat-island control strategies. In addition, air-temperature reductions on the order of 2.5-3.5C could be achieved if moderate and aggressive heat-island mitigation measures are adopted, respectively. A large-scale deployment of mitigation measures can bring additional indirect benefit to the urban area. For example, cooling outside air can improve the efficiency of cooling systems, reduce smog and greenhouse gas (GHG) emissions, and indirectly reduce pollution from power plants - all improving environmental health quality. This study has demonstrated the effectiveness of cool-roof technology as one of the urban heat-island control strategies for the Indian industrial and scientific communities and has provided an estimate of the national energy savings potential of cool roofs in India. These outcomes can be used for developing cool-roof building standards and related policies in India. Additional field studies, built upon the successes and lessons learned from this project, may be helpful to further confirm the scale of potential energy savings from the application of cooler roofs in various regions of India. In the future, a more rigorous meteorological simulation using urbanized (meso-urban) meteorological models should be conducted, which may produce a more accurate estimate of the air-temperature reductions for the entire urban area.

Akbari, Hashem; Xu, Tengfang; Taha, Haider; Wray, Craig; Sathaye, Jayant; Garg, Vishal; Tetali, Surekha; Babu, M. Hari; Reddy, K. Niranjan

2011-05-25T23:59:59.000Z

110

Radiant Heating | Department of Energy  

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

heating because it eliminates duct losses. People with allergies often prefer radiant heat because it doesn't distribute allergens like forced air systems can. Hydronic...

111

Heat Stroke  

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

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

112

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

E-Print Network (OSTI)

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

Weerawoot, Arunwattana

2010-01-01T23:59:59.000Z

113

Improvement to Air2Air Technology to Reduce Fresh-Water Evaporative Cooling Loss at Coal-Based Thermoelectric Power Plants ProMIS/Project No.:DE-NT0005647  

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

Improvement to AIr2AIr® technology Improvement to AIr2AIr® technology to reduce Fresh-WAter evAporAtIve coolIng loss At coAl-BAsed thermoelectrIc poWer plAnts promIs/project no. :de-nt0005647 Background The production of electricity requires a reliable, abundant, and predictable source of freshwater - a resource that is limited in many parts of the United States and throughout the world. The process of thermoelectric generation from fossil fuels such as coal, oil, and natural gas is water intensive. According to the 2000 U.S. Geological Survey, thermoelectric-power withdrawals accounted for 48 percent of total water use, 39 percent of total freshwater withdrawals (136 billion gallons per day) for all categories, and 52 percent of fresh surface water withdrawals. As a growing economy drives the need for more electricity, demands on freshwater

114

Optimized Control Of Steam Heating Coils  

E-Print Network (OSTI)

Steam has been widely used as the source of heating in commercial buildings and industries throughout the twentieth century. Even though contemporary designers have moved to hot water as the primary choice for heating, a large number of facilities still use steam for heating. Medical campuses with on-site steam generation and extensive distribution systems often serve a number of buildings designed prior to the mid-1980s. The steam is typically used for preheat as its high thermal content helps in heating the air faster and prevents coils from freezing in locations with extreme weather conditions during winter. The present work provides a comprehensive description of the various types of steam heating systems, steam coils, and valves to facilitate the engineer's understanding of these steam systems. A large percentage of the steam coils used in buildings are provided with medium pressure steam. Veterans Integrated Service Network and Army Medical Command Medical Facilities are examples which use medium pressure steam for heating. The current design manual for these medical facilities recommends steam at 30psig be provided to these coils. In certain cases although the steam heating coil is designed for a 5psig steam pressure, it is observed that higher pressure steam is supplied at the coil. A higher steam pressure may lead to excessive heating, system inefficiency due to increased heat loss, simultaneous heating and cooling, and increased maintenance cost. Field experiments were conducted to evaluate the effect of lowering steam pressure on the system performance. A 16% reduction in temperature rise across the coil was found when the steam pressure in the coil was reduced from 15psig to 5psig. The rise in temperature with lower pressure steam was sufficient to prevent coil freeze-up even in the most severe weather conditions. Additional benefits of reduced steam pressure are reduced flash steam losses (flash steam is vapor or secondary steam formed when hot condensate from the coil is discharged into a lower pressure area, i.e., the condensate return line) and radiation losses, increased flow of air through the coil thereby reducing air stratification and reduced energy losses in the event of actuator failure. The work also involved evaluating the existing control strategies for the steam heating system. New control strategies were developed and tested to address the short comings of existing sequences. Improved temperature control and occupant comfort; elimination of valve hunting and reduced energy consumption were benefits realized by implementing these measures.

Ali, Mir Muddassir

2011-12-01T23:59:59.000Z

115

Using Cool Roofs to Reduce Energy Use, Greenhouse Gas Emissions, and Urban Heat-island Effects: Findings from an India Experiment  

E-Print Network (OSTI)

coating comparison of air-conditioning energy usage for bothtemperature, heat flux, and air conditioning electricity useHourly time series of air conditioning and non-conditioning

Akbari, Hashem

2011-01-01T23:59:59.000Z

116

Factsheet on Summer Heat Gain and Winter Heat Loss In the summer we often feel warm in buildings and in the winter we may feel cold. This may be due  

E-Print Network (OSTI)

is lost as heat. energy Eg 2 31 Absorption process #12;ELEG620: Solar Electric Systems University single sided buried contact solar cell. Buried contact solar cells used in building-integrated application at G8 Summit Building, England. #12;ELEG620: Solar Electric Systems University of Delaware, ECE

117

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

Science Conference Proceedings (OSTI)

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

2012-12-14T23:59:59.000Z

118

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

119

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

120

Modular panels prevent window heat losses  

SciTech Connect

A Parker Hannifin plant in Cleveland found it possible to provide insulation which would handle a variety of temperature changes. The answer was a modular insulation system which covers windows in the winter, yet allows for adequate ventilation in the summer.

1981-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduce heat loss" 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

Experimental testing and analytical analysis of a plastic panel heat exchanger for greenhouse heating  

SciTech Connect

The performance of a plastic panel-type heat exchanger, suitable for greenhouse heating using low-grade (25 to 60/sup 0/C water) power plant reject heat, was investigated theoretically and experimentally. The theoretical analysis showed that a plastic panel heat exchanger would have an overall heat transfer coefficient, U/sub 0/, of about 18 w/m/sup 2/-/sup 0/C compared to about 12 w/m/sup 2/-/sup 0/C for a fin-tube heat exchanger, under typical greenhouse conditions. Furthermore the plastic heat exchanger would require less fan power due to reduced air pressure losses. The experimental data revealed a similar functional relationship for U/sub 0/ and air flow when compared with the theoretical calculations, however the experimental values of U/sub 0/ were consistently larger by 20 to 30%. It was concluded that a properly designed plastic heat exchanger can compete with metal fin tube type exchangers on a performance basis, but the plastic heat exchangers are 3 to 4 times larger by volume. However, because of the lower cost of plastic, a substantial cost reduction is expected. It appears that further study, examining heat exchanger lifetime, performance and costs, is warranted.

Olszewski, M.; Thomas, J.F.

1980-02-01T23:59:59.000Z

122

Local entropy generation analysis of a rotary magnetic heat pump regenerator  

SciTech Connect

The rotary magnetic heat pump has attractive thermodynamic performance but it is strongly influenced by the effectiveness of the regenerator. This study uses local entropy generation analysis to evaluate the regenerator design and to suggest design improvements. The results show that performance of the proposed design is dominated by heat transfer related entropy generation. This suggests that enhancement concepts that improve heat transfer should be considered, even if the enhancement causes a significant increase in viscous losses (pressure drop). One enhancement technique, the use of flow disrupters, was evaluated and the results showed that flow disrupters can significantly reduce thermodynamic losses.

Drost, M.K.; White, M.D.

1990-04-01T23:59:59.000Z

123

Building Energy Software Tools Directory: HEAT3  

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

be described in a rectangular grid. HEAT3 can be used for analyses of thermal bridges, heat transfer through corners of a window, heat loss from a house to the ground, to...

124

Waste Heat Management Options: Industrial Process Heating Systems  

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

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

125

FEMP-Solar Water Heating  

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

Fact sheet details solar water heating and how to use the sun to heat domestic water in any climate. Document explains how solar water heating helps to save energy, reduce utility costs, and preserve the environment.

126

Comparison of natural convection heat exchangers for solar water heating systems  

DOE Green Energy (OSTI)

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

Davidson, J.; Liu, W.

1998-09-15T23:59:59.000Z

127

DHE (downhole heat exchangers). [Downhole Heat Exchangers (DHE)  

DOE Green Energy (OSTI)

The use of downhole heat exchangers (DHE) for residential or commercial space and domestic water heating and other applications has several desirable features. Systems are nearly or completely passive -- that is, no or very little geothermal water or steam is produced from the well either reducing or completely eliminating surface environmental concerns and the need for disposal systems or injection wells. Initial cost of pumps and installation are eliminated or reduced along with pumping power costs and maintenance costs associated with pumping often corrosive geothermal fluids. Many residential and small commercial systems do not require circulating pumps because the density difference in the incoming and outgoing sides of the loop are sufficient to overcome circulating friction losses in the entire system. The major disadvantage of DHEs is their dependence on natural heat flow. In areas where geological conditions provide high permeability and a natural hydraulic gradient, DHEs can provide a substantial quantity of heat. A single 500-ft (152 m) well in Klamath Falls, Oregon, supplies over one megawatt thermal and output is apparently limited by the surface area of pipe that can be installed in the well bore. In contrast, DHEs used in conjunction with heat pumps may supply less than 8 KW from a well of similar depth. Here output is limited by conductive heat flow with perhaps a small contribution from convection near the well bore. The highest capacity DHE reported to date, in Turkey, supplies 6 MW thermal from an 820-ft (250 m) well. There were two main goals for this project. The first was to gather, disseminate and exchange internationally information on DHES. The second was to perform experiments that would provide insight into well bore/aquifer interaction and thereby provide more information on which to base DHE designs. 27 refs., 31 figs., 3 tabs.

Culver, G.

1990-11-01T23:59:59.000Z

128

Theoretical Design of a Thermosyphon for Efficient Process Heat Removal from Next Generation Nuclear Plant (NGNP) for Production of Hydrogen  

DOE Green Energy (OSTI)

The work reported here is the preliminary analysis of two-phase Thermosyphon heat transfer performance with various alkali metals. Thermosyphon is a device for transporting heat from one point to another with quite extraordinary properties. Heat transport occurs via evaporation and condensation, and the heat transport fluid is re-circulated by gravitational force. With this mode of heat transfer, the thermosyphon has the capability to transport heat at high rates over appreciable distances, virtually isothermally and without any requirement for external pumping devices. For process heat, intermediate heat exchangers (IHX) are required to transfer heat from the NGNP to the hydrogen plant in the most efficient way possible. The production of power at higher efficiency using Brayton Cycle, and hydrogen production requires both heat at higher temperatures (up to 1000oC) and high effectiveness compact heat exchangers to transfer heat to either the power or process cycle. The purpose for selecting a compact heat exchanger is to maximize the heat transfer surface area per volume of heat exchanger; this has the benefit of reducing heat exchanger size and heat losses. The IHX design requirements are governed by the allowable temperature drop between the outlet of the NGNP (900oC, based on the current capabilities of NGNP), and the temperatures in the hydrogen production plant. Spiral Heat Exchangers (SHE’s) have superior heat transfer characteristics, and are less susceptible to fouling. Further, heat losses to surroundings are minimized because of its compact configuration. SHEs have never been examined for phase-change heat transfer applications. The research presented provides useful information for thermosyphon design and Spiral Heat Exchanger.

Piyush Sabharwall; Fred Gunnerson; Akira Tokuhiro; Vivek Utgiker; Kevan Weaver; Steven Sherman

2007-10-01T23:59:59.000Z

129

Corona losses dependence from the conductor diameter  

Science Conference Proceedings (OSTI)

This paper presents possibility to decrease the corona power losses in overhead transmission lines. Corona power losses can be reduced by increasing the diameter of the conductor and used bundled conductors per phase. The objectives were to determine ... Keywords: corona model, critical disruptive voltage, electric discharge, electric field, power losses, transmission line

Isuf Krasniqi; Vjollca Komoni; Avni Alidemaj; Gazmend Kabashi

2011-10-01T23:59:59.000Z

130

Shield Losses in Medium-Voltage Cables  

Science Conference Proceedings (OSTI)

Utilities can substantially reduce cable costs and circulating current losses by optimizing the design of concentric neutral conductors for underground distribution cables and by configuring installed cables to minimize energy loss. This guide shows how to design neutral conductors for maximum cost-effectiveness and includes calculations of circulating current losses and ampacities for commonly used cables.

1987-12-14T23:59:59.000Z

131

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

132

Energy Efficient Steam Trapping of Trace Heating Systems  

E-Print Network (OSTI)

Since as many as 40-60% of a plant's steam traps may be used on steam tracer lines, it is essential to select the correct, properly sized 'traps'; to optimize the efficient removal of condensate while providing maximum heat transfer to maintain desired product temperatures and greatly reduce steam losses. Factors related to achieving uniform product temperatures and maximum heat transfer rates and energy efficiency are: 1.Types and Methods used for Steam Tracing; 2. Systematic heat balance required to achieve economic tracer lengths; 3. Maximum allowable trapping distance for specific applications 4.Data important to determine condensate loads; 5. Trap selection, sizing, good installation practices, and proper maintenance. Using an engineered approach to steam trapping of trace heating systems have resulted in stable tracer line temperatures while reducing steam consumption 10-50% with minimum maintenance.

Krueger, R. G.; Wilt, G. W.

1981-01-01T23:59:59.000Z

133

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

134

Determining the temperature field for cylinder symmetrical heat conduction problems in unsteady heat conduction in finite space  

Science Conference Proceedings (OSTI)

This paper proposes to present a new method to calculate unsteady heat conduction for cylinder symmetrical geometry. We will investigate the situation where the temperature field and heat flux created around a heat source placed in finite space are determined. ... Keywords: Garbai's integral equation, Laplace transformation, determining the temperate field, district heating pipes, geothermal producing pipe, heat flux density, heat loss, heat pump

László Garbai; Szabolcs Méhes

2007-05-01T23:59:59.000Z

135

Efficiency and Loss Models for Key Electronic Components of Hybrid and Plug-in Hybrid Electric Vehicles' Electrical Propulsion Systems  

DOE Green Energy (OSTI)

Isolated gate bipolar transistors (IGBTs) are widely used in power electronic applications including electric, hybrid electric, and plug-in hybrid electric vehicles (EVs, HEVs, and PHEVs). The trend towards more electric vehicles (MEVs) has demanded the need for power electronic devices capable of handling power in the range of 10-100 kW. However, the converter losses in this power range are of critical importance. Therefore, thermal management of the power electronic devices/converters is crucial for the reliability and longevity of the advanced vehicles. To aid the design of heat exchangers for the IGBT modules used in propulsion motor drives, a loss model for the IGBTs is necessary. The loss model of the IGBTs will help in the process of developing new heat exchangers and advanced thermal interface materials by reducing cost and time. This paper deals with the detailed loss modeling of IGBTs for advanced electrical propulsion systems. An experimental based loss model is proposed. The proposed loss calculation method utilizes the experimental data to reconstruct the loss surface of the power electronic devices by means of curve fitting and linear extrapolating. This enables the calculation of thermal losses in different voltage, current, and temperature conditions of operation. To verify the calculation method, an experimental test set-up was designed and built. The experimental set-up is an IGBT based bi-directional DC/DC converter. In addition, simulation results are presented to verify the proposed calculation method.

Cao, J.; Bharathan, D.; Emadi, A.

2007-01-01T23:59:59.000Z

136

Heat Pumps | Department of Energy  

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

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

137

Electrically heated particulate filter with reduced stress  

DOE Patents (OSTI)

A system comprises a particulate matter (PM) filter comprising an inlet for receiving exhaust gas. A zoned heater is arranged in the inlet and comprises a resistive heater comprising N zones, where N is an integer greater than one. Each of the N zones comprises M sub-zones, where M is an integer greater than one. A control module selectively activates one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones and deactivates others of the N zones.

Gonze, Eugene V.

2013-03-05T23:59:59.000Z

138

Heat pipe system  

SciTech Connect

A heat pipe diode device for transferring heat from a heat source component to a heat sink wall is described. It contains a heat pipe body member attached to the best source; the heat source having a wall forming at least a portion of the normal evaporator section of the heat pipe diode; a working fluid within the body member; a cover for the heat pipe diode forming at least a portion of the heat sink wall; the cover forming the normal condenser for the heat pipe diode; a wick connected between the condenser and the evaporator of the heat pipe diode; means for retaining the wick adjacent the heat pipe wall; a wick support plate adjacent to the cover; the wick being attached to the support plate; means for holding the wick in contact with the cover; and means, responsive to excessive temperatures at the heat sink wall, for moving the support plate and a portion of the wick away from the cover to thereby substantially reduce heat flow in the reverse direction through said heat pipe diode device.

Kroebig, H.L.; Riha, F.J. III

1974-12-03T23:59:59.000Z

139

coastal loss | NOLA DEFENDER  

U.S. Energy Information Administration (EIA)

BP Oil Doubled Wetland Loss, Study Says Posted Tuesday, ... coastal loss; Deepwater Horizon; louisiana coast; Oil; proceedings of the national academy ...

140

Heat reclaimer  

Science Conference Proceedings (OSTI)

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

Bellaff, L.

1981-10-20T23:59:59.000Z

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


141

Heat pipe heat amplifier  

SciTech Connect

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

Arcella, F.G.

1978-08-15T23:59:59.000Z

142

Spectral Effects on Fast Wave Core Heating and Current Drive  

SciTech Connect

Recent results obtained with high harmonic fast wave (HHFW) heating and current drive (CD) on NSTX strongly support the hypothesis that the onset of perpendicular fast wave propagation right at or very near the launcher is a primary cause for a reduction in core heating efficiency at long wavelengths that is also observed in ICRF heating experiments in numerous tokamaks. A dramatic increase in core heating efficiency was first achieved in NSTX L-mode helium majority plasmas when the onset for perpendicular wave propagation was moved away from the antenna and nearby vessel structures. Efficient core heating in deuterium majority L mode and H mode discharges, in which the edge density is typically higher than in comparable helium majority plasmas, was then accomplished by reducing the edge density in front of the launcher with lithium conditioning and avoiding operational points prone to instabilities. These results indicate that careful tailoring of the edge density profiles in ITER should be considered to limit rf power losses to the antenna and plasma facing materials. Finally, in plasmas with reduced rf power losses in the edge regions, the first direct measurements of high harmonic fast wave current drive were obtained with the motional Stark effect (MSE) diagnostic. The location and radial dependence of HHFW CD measured by MSE are in reasonable agreement with predictions from both full wave and ray tracing simulations.

C.K. Phillips, R.E. Bell, L.A. Berry, P.T. Bonoli, R.W. Harvey, J.C. Hosea, E.F. Jaeger, B.P. LeBlanc, P.M. Ryan, G. Taylor, E.J. Valeo, J.R. Wilson, J.C. Wright, H. Yuh, and the NSTX Team

2009-05-11T23:59:59.000Z

143

Spectral effects on fast wave core heating and current drive  

Science Conference Proceedings (OSTI)

Recent results obtained with high harmonic fast wave (HHFW) heating and current drive (CD) on NSTX strongly support the hypothesis that the onset of perpendicular fast wave propagation right at or very near the launcher is a primary cause for a reduction in core heating efficiency at long wavelengths that is also observed in ICRF heating experiments in numerous tokamaks. A dramatic increase in core heating efficiency was first achieved in NSTX L-mode helium majority plasmas when the onset for perpendicular wave propagation was moved away from the antenna and nearby vessel structures. Efficient core heating in deuterium majority L-mode and H-mode discharges, in which the edge density is typically higher than in comparable helium majority plasmas, was then accomplished by reducing the edge density in front of the launcher with lithium conditioning and avoiding operational points prone to instabilities. These results indicate that careful tailoring of the edge density profiles in ITER should be considered to limit radio frequency (rf) power losses to the antenna and plasma facing materials. Finally, in plasmas with reduced rf power losses in the edge regions, the first direct measurements of HHFW CD were obtained with the motional Stark effect (MSE) diagnostic. The location and radial dependence of HHFW CD measured by MSE are in reasonable agreement with predictions from both full wave and ray tracing simulations.

Phillips, Cynthia [Princeton Plasma Physics Laboratory (PPPL); Bell, R. E. [Princeton Plasma Physics Laboratory (PPPL); Berry, Lee [Oak Ridge National Laboratory (ORNL); Jaeger, Erwin Frederick [ORNL; Ryan, Philip Michael [ORNL; Wilgen, John B [ORNL

2009-01-01T23:59:59.000Z

144

Radiant Heating  

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

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

145

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

E-Print Network (OSTI)

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

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

2012-01-01T23:59:59.000Z

146

Proceedings: International Conference on Boiler Tube Failures and Heat Recovery Steam Generator (HRSG) Tube Failures and Inspections  

SciTech Connect

Tube failures remain the leading cause of availability loss in conventional fossil plants and combined cycle/heat recovery steam generator (HRSG) plants. These conference proceedings address state-of-the-art practices and techniques worldwide for understanding and reducing tube failures.

None

2002-10-01T23:59:59.000Z

147

Gas heat transfer in a heated vertical channel under deteriorated turbulent heat transfer regime  

E-Print Network (OSTI)

Passive cooling via natural circulation of gas after a loss of coolant (LOCA) accident is one of the major goals of the Gas-cooled Fast Reactor (GFR). Due to its high surface heat flux and low coolant velocities under ...

Lee, Jeongik

2007-01-01T23:59:59.000Z

148

Gas Heat Transfer in a Heated Vertical Channel under Deteriorated Turbulent Heat Transfer Regime  

E-Print Network (OSTI)

Passive cooling via natural circulation of gas after a loss of coolant (LOCA) accident is one of the major goals of the Gas-cooled Fast Reactor (GFR). Due to its high surface heat flux and low coolant velocities under ...

Lee, Jeongik

149

Design of a tube bank waste heat reclaimer for residential heating systems  

SciTech Connect

Forced convection tube bank heat reclaimers are analyzed in detail for residential natural gas and oil-fired furnaces that are controlled by natural draft. Optimum reclaimer designs are obtained based on improved system efficiency, and considerations regarding manufacturing costs. Each reclaimer meets safety restrictions regarding allowable system pressure losses and minimum chimney gas temperatures. Reclaimer size and overall weight are also considered. Computer-generated solutions aid in determining heat recovery as a function of furnace fuel, furnace efficiency, ambient temperature, flue pipe size, and chimney height. The analysis considers a range of furnace efficiencies from 50 to 80%, and ambient temperatures from 0 to 60/sup 0/F, which are values considered typical for most domestic combustion heating equipment. Flue pipe sizes range from 4 to 6 inches in diameter and are 2 to 4 feet long. Chimney sizes range from 5 to 7 inches in equivalent diameter and include draft heights from 15 to 35 feet. The piping sizes correspond to furnace input capacities ranging from 50,000 to 170,000 Btu/h. For many domestic heating systems, the potential exists to recover the lost heat by as much as 30%, and to reduce fuel costs by as much as 15% by installing a flue pipe heat reclaimer.

Gretsinger, K.M.; Elias, T.I.

1987-01-01T23:59:59.000Z

150

When Do Losses Count?  

Science Conference Proceedings (OSTI)

Current global and national databases that monitor losses from natural hazards suffer from a number of limitations, which in turn lead to misinterpretation and fallacies concerning the “truthfulness” of hazard loss data. These biases often go ...

Melanie Gall; Kevin A. Borden; Susan L. Cutter

2009-06-01T23:59:59.000Z

151

Evaluating Transformer Losses  

E-Print Network (OSTI)

This paper outlines how to determine what transformer losses cost and how to evaluate transformer bids to optimize the investment.

Grun, R. L. Jr.

1989-09-01T23:59:59.000Z

152

Reduce Stress!  

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

Stress! Stress! x Take a break every hour. Do some relaxation or stretching exercises or talk with someone about topics unrelated to work. Give your body and mind a rest. x Massage your hands and forearms several times a day with a vitamin E lotion. The massage will improve circulation and break up adhesions. Since you can't touch a keyboard until the lotion is absorbed, it also enforces a good break. x Massage the muscles in your neck working your way down from the skull to the shoulders, applying more force to the larger muscles as you go down. x Periodically evaluate your environment for ways to reduce stress. Try to keep your desk uncluttered so you can always find things. Make sure programs are set up correctly on the computer, and see if you can use a macro program to reduce

153

A Perspective on Reducing Losses from Natural Hazards  

Science Conference Proceedings (OSTI)

Editor's Note: This article is the first in a series of three articles based on apresentation to the Symposium on the International Decade for Natural DisasterReduction held 24 January 1994 in Nashville, Tennessee. The symposium washeld in ...

Gilbert F. White

1994-07-01T23:59:59.000Z

154

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

155

Fundamental heat transfer experiments of heat pipes for turbine cooling  

SciTech Connect

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

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

1998-07-01T23:59:59.000Z

156

Reducing Safety Flaring through Advanced Control  

E-Print Network (OSTI)

An advanced process control application, using DMCplus® (Aspen Technology, Inc.), was developed to substantially reduce fuel gas losses to the flare at a large integrated refining / petrochemical complex. Fluctuations in internal fuel gas system pressure required changes in C3/C4 make-up gas usage. These changes led, in turn, to some instability in the fuel gas system that sometimes required purge to the safety flare system to stabilize. As the composition of the fuel gas supply changed, so did its heating value, which caused fluctuations in the control of various fuel gas consumers. The DMCplus application now controls fuel gas pressure tightly and also stabilizes the fuel gas heating value. The understanding of each fuel gas provider and user was essential to the success of this application, as was the design of the DMCplus application. SmartStepTM (Aspen Technology, Inc.) - automated testing software - was used to efficiently develop the DMCplus models; however, a number of models were developed prior to the plant test period using long-term plant history data.

Hokanson, D.; Lehman, K.; Matsumoto, S.; Takai, N.; Takase, F.

2010-01-01T23:59:59.000Z

157

Solar heat pipe feedback turbogenerator  

SciTech Connect

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

Decker, B.J.

1978-10-24T23:59:59.000Z

158

Heating Alloys  

Science Conference Proceedings (OSTI)

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

159

Heating Systems  

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

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

160

Distribution System Losses Evaluation  

Science Conference Proceedings (OSTI)

Currently, there is not an industry standard on how utilities calculate and account for electrical losses and reductions in electric system losses. Computer models used to analyze power flows typically only include the primary components of the distribution system infrastructure. More detailed electric system models can benefit utilities by providing more accurate loss calculations as well as benefits for system planning and engineering. The utility industry could benefit from having a consistent and uni...

2008-12-16T23:59:59.000Z

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


161

EVALUATION OF A SULFUR OXIDE CHEMICAL HEAT STORAGE PROCESS FOR A STEAM SOLAR ELECTRIC PLANT  

E-Print Network (OSTI)

Exchanger 1 . 3. The Condensers . Reboiler . . . . BoilerNet Power Waste Heat Trimmer Dist. Condenser Turbine SteamLeaks LP Turbine Condenser Misc. Heat Losses Total Waste

Dayan, J.

2011-01-01T23:59:59.000Z

162

Solar heating and cooling diode module  

DOE Patents (OSTI)

A high efficiency solar heating system comprising a plurality of hollow modular units each for receiving a thermal storage mass, the units being arranged in stacked relation in the exterior frame of a building, each of the units including a port for filling the unit with the mass, a collector region and a storage region, each region having inner and outer walls, the outer wall of the collector region being oriented for exposure to sunlight for heating the thermal storage mass; the storage region having an opening therein and the collector region having a corresponding opening, the openings being joined for communicating the thermal storage mass between the storage and collector regions by thermosiphoning; the collector region being disposed substantially below and in parallel relation to the storage region in the modular unit; and the inner wall of the collector region of each successive modular unit in the stacked relation extending over the outer wall of the storage region of the next lower modular unit in the stacked relation for reducing heat loss from the system. Various modifications and alternatives are disclosed for both heating and cooling applications.

Maloney, Timothy J. (Winchester, VA)

1986-01-01T23:59:59.000Z

163

Energy losses in switches  

DOE Green Energy (OSTI)

The authors experiments show energy losses between 2 and 10 times that of the resistive time predictions. The experiments used hydrogen, helium, air, nitrogen, SF{sub 6} polyethylene, and water for the switching dielectric. Previously underestimated switch losses have caused over predicting the accelerator outputs. Accurate estimation of these losses is now necessary for new high-efficiency pulsed power devices where the switching losses constitute the major portion of the total energy loss. They found that the switch energy losses scale as (V{sub peak}I{sub peak}){sup 1.1846}. When using this scaling, the energy losses in any of the tested dielectrics are almost the same. This relationship is valid for several orders of magnitude and suggested a theoretical basis for these results. Currents up to .65 MA, with voltages to 3 MV were applied to various gaps during these experiments. The authors data and the developed theory indicates that the switch power loss continues for a much longer time than the resistive time, with peak power loss generally occurring at peak current in a ranging discharge instead of the early current time. All of the experiments were circuit code modeled after developing a new switch loss version based on the theory. The circuit code predicts switch energy loss and peak currents as a function of time. During analysis of the data they noticed slight constant offsets between the theory and data that depended on the dielectric. They modified the plasma conductivity for each tested dielectric to lessen this offset.

Martin, T.H.; Seamen, J.F.; Jobe, D.O.

1993-07-01T23:59:59.000Z

164

Heat recovery in a laundry system  

SciTech Connect

In a laundry system including a washer, a dryer, and a water heater, improvement is disclosed of using a heat pipe to recover waste heat, whether it be from the hot air exhaust of the dryer or from the conductive losses from the dryer and to transfer that heat to the feed water of the water heater.

George, O.F.

1981-06-30T23:59:59.000Z

165

Aging, Estrogen Loss and Epoxyeicosatrienoic Acids Alison R. Lee1.  

E-Print Network (OSTI)

Aging, Estrogen Loss and Epoxyeicosatrienoic Acids (EETs) Alison R. Lee1. , Angela S. Pechenino1 loss, caused by menopause, and aging have inflammatory consequences. Epoxyeicosatrienoic acids (EETs cyclooxygenases and lipoxygenases. We hypothesized that aging and estrogen loss would reduce levels of anti

Hammock, Bruce D.

166

Hybrid Geothermal Heat Pump Systems  

Science Conference Proceedings (OSTI)

Hybrid geothermal heat pump systems offer many of the benefits of full geothermal systems but at lower installed costs. A hybrid geothermal system combines elements of a conventional water loop heat pump system in order to reduce the geothermal loop heat exchanger costs, which are probably the largest cost element of a geothermal system. These hybrid systems have been used successfully where sufficient ground space to install large heat exchangers for full geothermal options was unavailable, or where the...

2009-12-21T23:59:59.000Z

167

Modeling the Loss Distribution  

Science Conference Proceedings (OSTI)

In this paper, we focus on modeling and predicting the loss distribution for credit risky assets such as bonds and loans. We model the probability of default and the recovery rate given default based on shared covariates. We develop a new class of default ... Keywords: Basel II, default prediction, loss distribution, recovery rates

Sudheer Chava; Catalina Stefanescu; Stuart Turnbull

2011-07-01T23:59:59.000Z

168

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

169

Kinetics of the direct electric heating of a stationary bed of activated charcoal  

SciTech Connect

Direct electric heating by passing an electrical current directly through a bed of adsorbent may prove to be an efficient means of regenerating activated charcoal in continuous and batch adsorption processes. Obvious advantages of this type of regeneration are its almost complete lack of inertia, which makes it possible to reduce the number and dimensions of the adsorbers, and its highly efficient use of energy due to the small number of steps in the conversion of the energy, as well as the reduction of heat losses involved in warming the structure and making up for losses to the surroundings. The authors consider the kinetics of direct electric heating of a stationary bed of activated charcoal not containing adsorbed substances.

Marfin, M.N.; Shumyatskii, Yu.I.

1987-08-20T23:59:59.000Z

170

Effect of steam generator configuration in a loss of the RHR during mid-loop operation at PKL facility  

SciTech Connect

The loss of the residual heat removal system in mid-loop conditions may occur with a non-negligible contribution to the plant risk, so the analysis of the accidental sequences and the actions to mitigate the accident are of great interest in shutdown conditions. In order to plan the appropriate measures to mitigate the accident is necessary to understand the thermal-hydraulic processes following the loss of the residual heat removal system during shutdown. Thus, transients of this kind have been simulated using best-estimate codes in different integral test facilities and compared with experimental data obtained in different facilities. In PKL (Primaerkreislauf-Versuchsanlage, primary coolant loop test facility) test facility different series of experiments have been undertaken to analyze the plant response in shutdown. In this context, the E3 and F2 series consist of analyzing the loss of the residual heat removal system with a reduced inventory in the primary system. In particular, the experiments were developed to investigate the influence of the steam generators secondary side configuration on the plant response, what involves the consideration of different number of steam generators filled with water and ready for activation, on the heat transfer mechanisms inside the steam generators U-tubes. This work presents the results of such experiments calculated using, RELAP5/Mod 3.3. (authors)

Villanueva, J. F.; Carlos, S.; Martorell, S.; Sanchez, F. [Dpto. Ingenieria Quimica Y Nuclear, Universitat Politecnica de Valencia, Camino Vera s/n, 46022 Valencia (Spain)

2012-07-01T23:59:59.000Z

171

An overview of MHD seawater thruster performance and loss mechanisms  

DOE Green Energy (OSTI)

Loss mechanisms affecting the performance of an MHD seawater thruster system have ben identified and discussed. Among those losses are the jet and nozzle losses, joule heating losses, surface potential and electro-chemical losses, frictional losses, and electrical end losses. Simple, but accurate, models have seen used to assess the relative and absolute magnitude of these losses and to investigate their influence on the overall thruster efficiency. A parametric study has been performed for a generic full size seawater vehicle propelled by an MHD thruster at different operating conditions. The results of this study confirm that higher efficiencies can be achieved at high magnetic field strengths (> 10 Tesla). Furthermore, the results indicate that higher efficiencies can be maintained over a wide range of cruising speeds (2--20 m/s or 4--40 knots) at higher magnetic fields (20 Tesla).

Doss, E.D.; Geyer, H.K.

1992-01-01T23:59:59.000Z

172

An overview of MHD seawater thruster performance and loss mechanisms  

DOE Green Energy (OSTI)

Loss mechanisms affecting the performance of an MHD seawater thruster system have ben identified and discussed. Among those losses are the jet and nozzle losses, joule heating losses, surface potential and electro-chemical losses, frictional losses, and electrical end losses. Simple, but accurate, models have seen used to assess the relative and absolute magnitude of these losses and to investigate their influence on the overall thruster efficiency. A parametric study has been performed for a generic full size seawater vehicle propelled by an MHD thruster at different operating conditions. The results of this study confirm that higher efficiencies can be achieved at high magnetic field strengths (> 10 Tesla). Furthermore, the results indicate that higher efficiencies can be maintained over a wide range of cruising speeds (2--20 m/s or 4--40 knots) at higher magnetic fields (20 Tesla).

Doss, E.D.; Geyer, H.K.

1992-09-01T23:59:59.000Z

173

Experimental Research on Solar Assisted Heat Pump Heating System with Latent Heat Storage  

E-Print Network (OSTI)

Based on the status quo that conventional energy sources are more and more reduced and environmental pollution is increasingly serious, this paper presents a new model system of conserving energy and environmental protection, namely, a Solar Assisted Heat Pump Heating System with Latent Heat Storage. In this system, solar energy is the major heat source for a heat pump, and the supplementary heat source is soil. The disagreement in time between the space heat load and heat collected by solar heat collector is solved by latent heat storage. In order to obtain such system running conditions and effects in different heating periods, an experiment has been carried out during the whole heating period in Harbin, China. The experimental results show that this system is much better for heating in initial and late periods than that in middle periods. The average heating coefficient is 6.13 for heating in initial and late periods and 2.94 for heating in middle periods. At the same time, this paper also predicts system running properties in other regions.

Han, Z.; Zheng, M.; Liu, W.; Wang, F.

2006-01-01T23:59:59.000Z

174

Water Heating | Department of Energy  

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

Water Heating Water Heating Water Heating Infographic: Water Heaters 101 Everything you need to know about saving money on water heating costs Read more Selecting a New Water Heater Tankless? Storage? Solar? Save money on your water heating bill by choosing the right type of energy-efficient water heater for your needs. Read more Sizing a New Water Heater When buying a new water heater, bigger is not always better. Learn how to buy the right size of water heater. Read more You can reduce your monthly water heating bills by selecting the appropriate water heater for your home or pool and by using some energy-efficient water heating strategies. Some simple do-it-yourself projects, like insulating hot water pipes and lowering your water heating temperature, can also help you save money and energy on your water heating.

175

Public release of optimization of metallization scheme for thin emitter wrap-through solar cells for higher efficiency, reduced precious metal costs, and reduced stress.  

DOE Green Energy (OSTI)

Back-contact crystalline-silicon photovoltaic solar cells and modules offer a number of advantages, including the elimination of grid shadowing losses, reduced cost through use of thinner silicon substrates, simpler module assembly, and improved aesthetics. While the existing edge tab method for interconnecting and stringing edge-connected back contact cells is acceptably straightforward and reliable, there are further gains to be exploited when you have both contact polarities on one side of the cell. In this work, we produce 'busbarless' emitter wrap-through solar cells that use 41% of the gridline silver (Ag) metallization mass compared to the edge tab design. Further, series resistance power losses are reduced by extraction of current from more places on the cell rear, leading to a fill factor improvement of about 6% (relative) on the module level. Series resistance and current-generation losses associated with large rear bondpads and busbars are eliminated. Use of thin silicon (Si) wafers is enabled because of the reduced Ag metallization mass and by interconnection with conductive adhesives leading to reduced bow. The busbarless cell design interconnected with conductive adhesives passes typical International Electrotechnical Commission damp heat and thermal cycling test.

Ruby, Douglas Scott; Murphy, Brian (Advent Solar, Inc., Albuquerque, NM); Meakin, David (Advent Solar, Inc., Albuquerque, NM); Dominguez, Jason (Advent Solar, Inc., Albuquerque, NM); Hacke, Peter (Advent Solar, Inc., Albuquerque, NM)

2008-08-01T23:59:59.000Z

176

Impacts of Substation Transformer and Bus Configuration on Distribution Losses  

Science Conference Proceedings (OSTI)

The technical losses on Electricit de France (EDF) distribution networks are annually estimated at about 18 TWh. Since the costs for these losses are ultimately covered by the end-use tariff paid by the customers, EDF has many reasons to find a way to reduce them, including the desire to increase customer satisfaction, meet commitments for sustainable development, and anticipate future regulatory requirements. EDF has identified two main ways to reduce losses on distribution systems: developing new rules...

2009-03-26T23:59:59.000Z

177

Quench cooling under reduced gravity  

E-Print Network (OSTI)

We report the quench cooling experiments performed with liquid O2 under different levels of gravity simulated with the magnetic gravity compensation. A copper disk is quenched from 270K to 90K. It is found that the cooling time in microgravity is very long in comparison with any other gravity level. This phenomenon is explained by the isolation effect of the gas surrounding the disk. The liquid subcooling is shown to drastically improuve the heat exchange thus reducing the cooling time (about 20 times). The effect of subcooling on the heat transfer is analyzed at different gravity levels. It is shown that such type of experiments cannot be used for the analysis of the critical heat flux (CHF) of the boiling crisis. The minimum heat flux (MHF) of boiling is analyzed instead.

Chatain, D; Nikolayev, V S; Beysens, D

2013-01-01T23:59:59.000Z

178

Heat Pipe Integrated Microsystems  

SciTech Connect

The trend in commercial electronics packaging to deliver ever smaller component packaging has enabled the development of new highly integrated modules meeting the demands of the next generation nano satellites. At under ten kilograms, these nano satellites will require both a greater density electronics and a melding of satellite structure and function. Better techniques must be developed to remove the subsequent heat generated by the active components required to-meet future computing requirements. Integration of commercially available electronics must be achieved without the increased costs normally associated with current generation multi chip modules. In this paper we present a method of component integration that uses silicon heat pipe technology and advanced flexible laminate circuit board technology to achieve thermal control and satellite structure. The' electronics/heat pipe stack then becomes an integral component of the spacecraft structure. Thermal management on satellites has always been a problem. The shrinking size of electronics and voltage requirements and the accompanying reduction in power dissipation has helped the situation somewhat. Nevertheless, the demands for increased onboard processing power have resulted in an ever increasing power density within the satellite body. With the introduction of nano satellites, small satellites under ten kilograms and under 1000 cubic inches, the area available on which to place hot components for proper heat dissipation has dwindled dramatically. The resulting satellite has become nearly a solid mass of electronics with nowhere to dissipate heat to space. The silicon heat pipe is attached to an aluminum frame using a thermally conductive epoxy or solder preform. The frame serves three purposes. First, the aluminum frame provides a heat conduction path from the edge of the heat pipe to radiators on the surface of the satellite. Secondly, it serves as an attachment point for extended structures attached to the satellite such as solar panels, radiators, antenna and.telescopes (for communications or sensors). Finally, the packages make thermal contact to the surface of the silicon heat pipe through soft thermal pads. Electronic components can be placed on both sides of the flexible circuit interconnect. Silicon heat pipes have a number of advantages over heat pipe constructed from other materials. Silicon heat pipes offer the ability to put the heat pipe structure beneath the active components of a processed silicon wafer. This would be one way of efficiently cooling the heat generated by wafer scale integrated systems. Using this technique, all the functions of a satellite could be reduced to a few silicon wafers. The integration of the heat pipe and the electronics would further reduce the size and weight of the satellite.

Gass, K.; Robertson, P.J.; Shul, R.; Tigges, C.

1999-03-30T23:59:59.000Z

179

Low temperature barriers with heat interceptor wells for in situ processes  

DOE Patents (OSTI)

A system for reducing heat load applied to a frozen barrier by a heated formation is described. The system includes heat interceptor wells positioned between the heated formation and the frozen barrier. Fluid is positioned in the heat interceptor wells. Heat transfers from the formation to the fluid to reduce the heat load applied to the frozen barrier.

McKinzie, II, Billy John (Houston, TX)

2008-10-14T23:59:59.000Z

180

Modern Heating Options for Commercial/Institutional Buildings  

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

reducing the heating energy in buildings using a combination of low temperature boilers, heat recovery strategies and a new approach to geo-thermal systems. His data from...

Note: This page contains sample records for the topic "reduce heat loss" 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

Gas Water Heater Energy Losses  

E-Print Network (OSTI)

Insul. Thk. (in) 11. Supply Pipe Heat Trap (0,1,-1)* 12.Draw Pipe Heat Trap (0,1,-1)* * 0 = No heat trap 1 = Metallosses through the pipes by improving heat traps and by

Biermayer, Peter

2012-01-01T23:59:59.000Z

182

Heat Conduction  

Science Conference Proceedings (OSTI)

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

183

Drain Water Heat Recovery | Department of Energy  

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

Drain Water Heat Recovery Drain Water Heat Recovery Drain Water Heat Recovery June 15, 2012 - 6:20pm Addthis Diagram of a drain water heat recovery system. Diagram of a drain water heat recovery system. How does it work? Use heat from water you've already used to preheat more hot water, reducing your water heating costs. Any hot water that goes down the drain carries away energy with it. That's typically 80%-90% of the energy used to heat water in a home. Drain-water (or greywater) heat recovery systems capture this energy from water you've already used (for example, to shower, wash dishes, or wash clothing) to preheat cold water entering the water heater or going to other water fixtures. This reduces the amount of energy needed for water heating. How It Works Drain-water heat recovery technology works well with all types of water

184

Drain Water Heat Recovery | Department of Energy  

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

Drain Water Heat Recovery Drain Water Heat Recovery Drain Water Heat Recovery June 15, 2012 - 6:20pm Addthis Diagram of a drain water heat recovery system. Diagram of a drain water heat recovery system. How does it work? Use heat from water you've already used to preheat more hot water, reducing your water heating costs. Any hot water that goes down the drain carries away energy with it. That's typically 80%-90% of the energy used to heat water in a home. Drain-water (or greywater) heat recovery systems capture this energy from water you've already used (for example, to shower, wash dishes, or wash clothing) to preheat cold water entering the water heater or going to other water fixtures. This reduces the amount of energy needed for water heating. How It Works Drain-water heat recovery technology works well with all types of water

185

Heat exchanger  

DOE Patents (OSTI)

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

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

1979-01-01T23:59:59.000Z

186

Information Loss in Black Hole Evaporation  

E-Print Network (OSTI)

Parikh-Wilczek tunnelling framework is investigated again. We argue that Parikh-Wilczek's treatment, which satisfies the first law of black hole thermodynamics and consists with an underlying unitary theory, is only suitable for a reversible process. Because of the negative heat capacity, an evaporating black hole is a highly unstable system. That is, the factual emission process is irreversible, the unitary theory will not be satisfied and the information loss is possible.

Jingyi Zhang; Yapeng Hu; Zheng Zhao

2005-12-11T23:59:59.000Z

187

Influence of Heat Source Cooling Limitation on ORC System Layout ...  

Science Conference Proceedings (OSTI)

... compensates for the temperature loss induced by a second heat exchanger. ... Abart CDS - a New Compact Multi-pollutant Pot Gas and Alumina Handling ...

188

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...

189

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

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

190

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

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

191

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

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

192

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...

193

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...

194

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...

195

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...

196

Analysis of beam loss induced abort kicker instability  

SciTech Connect

Through more than a decade of operation, we have noticed the phenomena of beam loss induced kicker instability in the RHIC beam abort systems. In this study, we analyze the short term beam loss before abort kicker pre-fire events and operation conditions before capacitor failures. Beam loss has caused capacitor failures and elevated radiation level concentrated at failed end of capacitor has been observed. We are interested in beam loss induced radiation and heat dissipation in large oil filled capacitors and beam triggered thyratron conduction. We hope the analysis result would lead to better protection of the abort systems and improved stability of the RHIC operation.

Zhang W.; Sandberg, J.; Ahrens, L.; Fischer, W.; Hahn, H.; Mi, J.; Pai, C.; Tan, Y.

2012-05-20T23:59:59.000Z

197

DETAILED LOOP MODEL (DLM) ANALYSIS OF LIQUID SOLAR THERMOSIPHONS WITH HEAT EXCHANGERS  

E-Print Network (OSTI)

DLM on the other hand con- pipes heat loss from ows. para 11~ headers~ connecting pipes~ and heat exchanger tubes) isconnecting pipes (riser and downcomer) and a heat exchanger

Mertol, A.

2013-01-01T23:59:59.000Z

198

Emergency heat removal system for a nuclear reactor  

DOE Patents (OSTI)

A heat removal system for nuclear reactors serving as a supplement to an Emergency Core Cooling System (ECCS) during a Loss of Coolant Accident (LOCA) comprises a plurality of heat pipes having one end in heat transfer relationship with either the reactor pressure vessel, the core support grid structure or other in-core components and the opposite end located in heat transfer relationship with a heat exchanger having heat transfer fluid therein. The heat exchanger is located external to the pressure vessel whereby excessive core heat is transferred from the above reactor components and dissipated within the heat exchanger fluid.

Dunckel, Thomas L. (Potomac, MD)

1976-01-01T23:59:59.000Z

199

Assessing and Reducing Miscellaneous Electric Loads (MELs) in Lodging  

SciTech Connect

Miscellaneous electric loads (MELs) are the loads outside of a building's core functions of heating, ventilating, air conditioning, lighting, and water heating. This report reviews methods to reduce MELs in lodging.

Rauch, Emily M.

2011-09-01T23:59:59.000Z

200

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

E-Print Network (OSTI)

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

Oak Ridge National Laboratory

Note: This page contains sample records for the topic "reduce heat loss" 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

Nitrogen heat pipe for cryocooler thermal shunt  

SciTech Connect

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

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

1995-09-01T23:59:59.000Z

202

Catalogue of a Loss  

E-Print Network (OSTI)

Catalogue of a Loss is a collection of sixty-two prose poems written within the past year and half. The work is printed on 4x6 cards. Each poem may be read individually from a single card or the poems can be read in ...

Berger, Larisa (Larisa A.)

2012-01-01T23:59:59.000Z

203

Energy-efficient water heating  

SciTech Connect

This fact sheet describes how to reduce the amount of hot water used in faucets and showers, automatic dishwashers, and washing machines; how to increase water-heating system efficiency by lowering the water heater thermostat, installing a timer and heat traps, and insulating hot water pipes and the storage tank; and how to use off-peak power to heat water. A resource list for further information is included.

NONE

1995-01-01T23:59:59.000Z

204

Thermally activated heat pumps  

SciTech Connect

This article describes research to develop efficient gas-fired heat pumps heat and cool buildings without CFCs. Space heating and cooling use 46% of all energy consumed in US buildings. Air-conditioning is the single leading cause of peak demand for electricity and is a major user of chlorofluorocarbons (CFCs). Advanced energy conversion technology can save 50% of this energy and eliminate CFCs completely. Besides saving energy, advanced systems substantially reduce emissions of carbon dioxide (a greenhouse gas), sulfur dioxide, and nitrogen oxides, which contribute to smog and acid rain. These emissions result from the burning of fossil fuels used to generate electricity. The Office of Building Technologies (OBT) of the US Department of Energy supports private industry`s efforts to improve energy efficiency and increase the use of renewable energy in buildings. To help industry, OBT, through the Oak Ridge National Laboratory, is currently working on thermally activated heat pumps. OBT has selected the following absorption heat pump systems to develop: generator-absorber heat-exchange (GAX) cycle for heating-dominated applications in residential and light commercial buildings; double-condenser-coupled (DCC) cycle for commercial buildings. In addition, OBT is developing computer-aided design software for investigating the absorption cycle.

NONE

1995-05-01T23:59:59.000Z

205

Heat pipe turbine vane cooling  

SciTech Connect

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

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

1995-12-31T23:59:59.000Z

206

Synthesis of bulk FeHfBO soft magnetic materials and its loss characterization at megahertz frequency  

SciTech Connect

Magnetic core materials with low loss, high saturation magnetization, large permeability, and operating frequency above 1 MHz are in high demands for the next generation of miniaturized power electronics. Amorphous FeHfB ribbons with thickness around 20 {mu}m have been fabricated through melt-spinning. Different heat treatments were performed on the FeHfB ribbons, and the relations among heat treatments, microstructure, and magnetic properties have been explored. Properties such as coercivity (H{sub c}) of 2.0 Oe and saturation magnetic flux density (B{sub S}) of 1.2 T have been achieved in samples with exchange coupling. The losses can be minimized by balancing the hysteretic and eddy current losses and can be further reduced with additional magnetic field annealing. At 5 MHz with peak magnetic flux density of 20 mT, the materials show core losses comparable to the best ferrites, but with higher permeability value of about 200 and superior saturation induction of more than 1 T.

Zhou Yang; Kou Xiaoming; Warsi Muhammad, Asif; Lin Shuo; Harris, Brendan S.; Parsons, Paul E.; Xiao, John Q. [Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716 (United States); Mu Mingkai; Lee, Fred C. [Center for Power Electronics System, Virginia Polytechnic and State University, Blacksburg, Virginia 24060 (United States); Zhu Hao [Spectrum Magnetics LLC, Wilmington, Delaware 19804 (United States)

2013-05-07T23:59:59.000Z

207

New industrial heat pump applications to an integrated thermomechanical pulp and paper mill  

Science Conference Proceedings (OSTI)

Application of pinch technology US industries in an early screening study done by TENSA Services (DOE/ID/12583-1) identified potential for heat pumps in several industrial sectors. Among these, processes with large evaporation units were found to be some of the most promising sectors for advanced heat pump placement. This report summarizes the results of a study for Bowater Incorporated, Carolina Division. The units selected for this study are the thermo-mechanical pulper (TMP), kraft digester, evaporators, boiler feed water (BFW) train and pulp dryer. Based on the present level of operation, the following recommendations are made: 1. Install a mechanical vapor compression (MVR) heat pump between the TMP mill and {number sign}3 evaporator. This heat pump will compress the 22 psig steam from the TMP heat recovery system and use it to replace about 70% of the 60 psig steam required in {number sign} evaporator. The boiler feed water heat losses (in the low pressure deaerator) will be supplied by heat available in the TMR's zero psig vent steam. 2. Study the digester to verify the practicality of installing an MVR heat pump which will compress the dirty weapons from the cyclone separator. The compressed vapors can be directly injected into the digester and thus reduce the 135 psig steam consumption. 31 figs., 9 tabs.

Not Available

1991-01-01T23:59:59.000Z

208

Solar heat pipe testing of the Stirling thermal motors 4-120 Stirling engine  

DOE Green Energy (OSTI)

Stirling-cycle engines have been identified as a promising technology for the conversion of concentrated solar energy into usable electrical power. A 25kW electric system takes advantage of existing Stirling-cycle engines and existing parabolic concentrator designs. In previous work, the concentrated sunlight impinged directly on the heater head tubes of the Stirling Thermal Motors (STM) 4-120 engine. A Sandia-designed felt-metal-wick heat pipe receiver was fitted to the STM 4-120 engine for on-sun testing on Sandia`s Test Bed Solar Concentrator. The heat pipe uses sodium metal as an intermediate two-phase heat transfer fluid. The receiver replaces the directly-illuminated heater head previously tested. The heat pipe receiver provides heat isothermally to the engine, and the heater head tube length is reduced, both resulting in improved engine performance. The receiver also has less thermal losses than the tube receiver. The heat pipe receiver design is based on Sandia`s second-generation felt-wick heat pipe receiver. This paper presents the interface design, and compares the heat pipe/engine test results to those of the directly-illuminated receiver/engine package.

Andraka, C.E.; Rawlinson, K.S.; Moss, T.A.; Adkins, D.R.; Moreno, J.B.; Gallup, D.R.; Cordeiro, P.G. [Sandia National Labs., Albuquerque, NM (United States); Johansson, S. [Stirling Thermal Motors, Inc., Ann Arbor, MI (United States)

1996-07-01T23:59:59.000Z

209

Waste Heat Recovery From Stacks Using Direct-Contact Condensing Heat Exchange  

E-Print Network (OSTI)

Flue gases exiting the stack of a boiler create thermal losses normally amounting to 15 to 20 percent of the high heating value of the fuel fired. By capturing and using this lost energy using condensing heat recovery, the overall efficiency of the system can be raised to over 95 percent. This paper reviews the origins of stack heat losses, direct contact condensing heat recovery processes, the Rocket Research Company CON-X condensing recuperator equipment and systems, site specific case studies and fuels and condensate acidity. A detailed example of the determination of the magnitude of stack heat losses is presented along with a methodology for the reader to make a preliminary heat recovery evaluation.

Thorn, W. F.

1986-06-01T23:59:59.000Z

210

Energy Saving Absorption Heat Pump Water Heater  

energy savings and can reduce the use of fossil fuels by buildings. While conventional heat pump water heater designs are limited to using toxic ammonia water ...

211

Protecting the Investment in Heat Recovery with Boiler Economizers  

E-Print Network (OSTI)

Many people consider energy to be a crisis in remission -- even with continuing high fuel costs. Some voice concern over the long term security of an investment in flue gas heat recovery equipment. The concern generally involves the ability of an economizer or air heater to continue to perform efficiently without corrosion. The recognized economic advantages of an economizer result from its ability to convert heat losses into sources of energy. One of the most productive means of obtaining reduced energy costs lies in the improvements of the efficiency of steam generating boilers. Industrial and institutional boilers operating at pressures of 75 psig or greater are excellent applications. The maximum gain that can be safely achieved is governed by a number of technical and physical limitations. Among these are considerations of the economics, temperatures of the flue gas and water, and the potential for corrosion. This paper will discuss the economic and practical considerations of an economizer installation.

Roethe, L. A.

1985-05-01T23:59:59.000Z

212

A Model of Heat Conduction  

E-Print Network (OSTI)

We define a deterministic ``scattering'' model for heat conduction which is continuous in space, and which has a Boltzmann type flavor, obtained by a closure based on memory loss between collisions. We prove that this model has, for stochastic driving forces at the boundary, close to Maxwellians, a unique non-equilibrium steady state.

Collet, Pierre

2008-01-01T23:59:59.000Z

213

Phase Change Materials for Enhancing Heat Transfer in Thermal ...  

Science Conference Proceedings (OSTI)

One of the main issues with using phase change materials is that solidification often reduces total heat transfer, reducing the efficiency of the storage system.

214

Increased Energy Efficiency and Reduced HF Emissions with New ...  

Science Conference Proceedings (OSTI)

Presentation Title, Increased Energy Efficiency and Reduced HF Emissions with New Heat Exchanger. Author(s), Anders Kenneth Sorhuus, Geir Wedde, Ketil A.

215

Heat reclaimer  

Science Conference Proceedings (OSTI)

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

Parham, F.

1985-04-09T23:59:59.000Z

216

Geothermal shell and tube heat exchanger augmentation  

DOE Green Energy (OSTI)

The heat exchangers for a moderate temperature geothermal plant represent a major portion of the plant capital cost. Therefore, reduction in heat exchanger size will significantly improve the electrical power economics. The potential heat exchanger size reduction that could be achieved by reducing any combination heat transfer resistance terms is evaluated. A literature survey of heat transfer augmentation schemes is summarized and equations for evaluating the impact of cleaning frequency on heat exchanger size are presented. Recommendations are made specifically for the Raft River Thermal Loop, however, the techniques are applicable to any other geothermal plant or heat transfer system.

Neill, D.T.

1976-11-01T23:59:59.000Z

217

Heat transfer. [heat transfer roller employing a heat pipe  

SciTech Connect

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

Sarcia, D.S.

1978-05-23T23:59:59.000Z

218

Initial measurements of fast ion loss in KSTAR  

Science Conference Proceedings (OSTI)

A fast ion loss detector (FILD) has been installed and tested in Korea Superconducting Tokamak Advanced Research (KSTAR). KSTAR FILD measures the energy and the pitch-angle of the escaping ions with the striking positions on the scintillator plane. Measurements of the fast ion loss have been performed for the neutral beam heated plasmas. Initial experimental results indicate the prompt losses from neutral beam are dominant and the effects of the resonant magnetic perturbation on the fast ion loss are investigated. In addition, further design change of the detector-head in order to avoid excessive heat load and to detect the fusion products or the fast ions having order of MeV of energy is also discussed.

Kim, Junghee; Yoon, S. W.; Kim, W. C. [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of); Kim, Jun Young [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of); Department of Nuclear Fusion and Plasma Science, University of Science and Technology, Daejeon 305-350 (Korea, Republic of); Garcia-Munoz, M. [Max-Planck-Institut fuer Plasmaphysik, EURATOM-Association IPP, Garching D-85748 (Germany); Isobe, M. [National Institute for Fusion Science, Toki-shi 509-5292 (Japan)

2012-10-15T23:59:59.000Z

219

Return channel loss reduction in multi-stage centrifugal compressors  

E-Print Network (OSTI)

This thesis presents concepts for improving the performance of return channels in multi-stage centrifugal compressors. Geometries have been developed to reduce both separation and viscous losses. A number of different ...

Aubry, Anne-Raphaëlle

2012-01-01T23:59:59.000Z

220

Heat Pipe Solar Receiver Development Activities at Sandia National Laboratories  

DOE Green Energy (OSTI)

Over the past decade, Sandia National Laboratories has been involved in the development of receivers to transfer energy from the focus of a parabolic dish concentrator to the heater tubes of a Stirling engine. Through the isothermal evaporation and condensation of sodium. a heat-pipe receiver can efficiently transfer energy to an engine's working fluid and compensate for irregularities in the flux distribution that is delivered by the concentrator. The operation of the heat pipe is completely passive because the liquid sodium is distributed over the solar-heated surface by capillary pumping provided by a wick structure. Tests have shown that using a heat pipe can boost the system performance by twenty percent when compared to directly illuminating the engine heater tubes. Designing heat pipe solar receivers has presented several challenges. The relatively large area ({approximately}0.2 m{sup 2}) of the receiver surface makes it difficult to design a wick that can continuously provide liquid sodium to all regions of the heated surface. Selecting a wick structure with smaller pores will improve capillary pumping capabilities of the wick, but the small pores will restrict the flow of liquid and generate high pressure drops. Selecting a wick that is comprised of very tine filaments can increase the permeability of the wick and thereby reduce flow losses, however, the fine wick structure is more susceptible to corrosion and mechanical damage. This paper provides a comprehensive review of the issues encountered in the design of heat pipe solar receivers and solutions to problems that have arisen. Topics include: flow characterization in the receiver, the design of wick systems. the minimization of corrosion and dissolution of metals in sodium systems. and the prevention of mechanical failure in high porosity wick structures.

Adkins, D.R.; Andraka, C.E.; Moreno, J.B.; Moss, T.A.; Rawlinson, K.S.; Showalter, S.K.

1999-01-08T23:59:59.000Z

Note: This page contains sample records for the topic "reduce heat loss" 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

Heat Pipe Solar Receiver Development Activities at Sandia National Laboratories  

SciTech Connect

Over the past decade, Sandia National Laboratories has been involved in the development of receivers to transfer energy from the focus of a parabolic dish concentrator to the heater tubes of a Stirling engine. Through the isothermal evaporation and condensation of sodium. a heat-pipe receiver can efficiently transfer energy to an engine's working fluid and compensate for irregularities in the flux distribution that is delivered by the concentrator. The operation of the heat pipe is completely passive because the liquid sodium is distributed over the solar-heated surface by capillary pumping provided by a wick structure. Tests have shown that using a heat pipe can boost the system performance by twenty percent when compared to directly illuminating the engine heater tubes. Designing heat pipe solar receivers has presented several challenges. The relatively large area ({approximately}0.2 m{sup 2}) of the receiver surface makes it difficult to design a wick that can continuously provide liquid sodium to all regions of the heated surface. Selecting a wick structure with smaller pores will improve capillary pumping capabilities of the wick, but the small pores will restrict the flow of liquid and generate high pressure drops. Selecting a wick that is comprised of very tine filaments can increase the permeability of the wick and thereby reduce flow losses, however, the fine wick structure is more susceptible to corrosion and mechanical damage. This paper provides a comprehensive review of the issues encountered in the design of heat pipe solar receivers and solutions to problems that have arisen. Topics include: flow characterization in the receiver, the design of wick systems. the minimization of corrosion and dissolution of metals in sodium systems. and the prevention of mechanical failure in high porosity wick structures.

Adkins, D.R.; Andraka, C.E.; Moreno, J.B.; Moss, T.A.; Rawlinson, K.S.; Showalter, S.K.

1999-01-08T23:59:59.000Z

222

Electric Resistance Heating | Department of Energy  

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

Electric Resistance Heating Electric Resistance Heating Electric Resistance Heating June 24, 2012 - 4:51pm Addthis Baseboard heaters are one type of electric resistance heaters. | Photo courtesy of ©iStockphoto/drewhadley Baseboard heaters are one type of electric resistance heaters. | Photo courtesy of ©iStockphoto/drewhadley Electric resistance heating converts nearly 100% of the energy in the electricity to heat. However, most electricity is produced from coal, gas, or oil generators that convert only about 30% of the fuel's energy into electricity. Because of electricity generation and transmission losses, electric heat is often more expensive than heat produced in the home or business using combustion appliances, such as natural gas, propane, and oil furnaces. If electricity is the only choice, heat pumps are preferable in most

223

Energy Basics: Heat Pump Systems  

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

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

224

Heat reclaimer  

SciTech Connect

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

Horkey, E.J.

1982-06-29T23:59:59.000Z

225

Process Heating  

Science Conference Proceedings (OSTI)

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

2011-12-07T23:59:59.000Z

226

HEAT EXCHANGER  

DOE Patents (OSTI)

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

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

1962-10-23T23:59:59.000Z

227

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

228

FEMP--Solar Water Heating  

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

More than 1 million homeowners and 200,000 busi- More than 1 million homeowners and 200,000 busi- nesses in the United States are using the sun to heat domestic water efficiently in almost any climate. In summer, a solar system properly sized for a resi- dential building can meet 100% of the building's water-heating needs in most parts of the country. In winter, the system might meet only half of this need, so another source of heat is used to back up the solar system. In either case, solar water heating helps to save energy, reduce utility costs, and preserve the environment. A solar water-heating system's performance depends primarily on the outdoor temperature, the temperature to which the water is heated, and the amount of sunlight striking the collector-the device that actually captures the sun's energy.

229

Reduce Air Infiltration in Furnaces (English/Chinese) (Fact Sheet)  

Science Conference Proceedings (OSTI)

Chinese translation of the Reduce Air Infiltration in Furnaces fact sheet. Provides suggestions on how to improve furnace energy efficiency. Fuel-fired furnaces discharge combustion products through a stack or a chimney. Hot furnace gases are less dense and more buoyant than ambient air, so they rise, creating a differential pressure between the top and the bottom of the furnace. This differential, known as thermal head, is the source of a natural draft or negative pressure in furnaces and boilers. A well-designed furnace (or boiler) is built to avoid air leakage into the furnace or leakage of flue gases from the furnace to the ambient. However, with time, most furnaces develop cracks or openings around doors, joints, and hearth seals. These openings (leaks) usually appear small compared with the overall dimensions of the furnace, so they are often ignored. The negative pressure created by the natural draft (or use of an induced-draft fan) in a furnace draws cold air through the openings (leaks) and into the furnace. The cold air becomes heated to the furnace exhaust gas temperature and then exits through the flue system, wasting valuable fuel. It might also cause excessive oxidation of metals or other materials in the furnaces. The heat loss due to cold air leakage resulting from the natural draft can be estimated if you know four major parameters: (1) The furnace or flue gas temperature; (2) The vertical distance H between the opening (leak) and the point where the exhaust gases leave the furnace and its flue system (if the leak is along a vertical surface, H will be an average value); (3) The area of the leak, in square inches; and (4) The amount of operating time the furnace spends at negative pressure. Secondary parameters that affect the amount of air leakage include these: (1) The furnace firing rate; (2) The flue gas velocity through the stack or the stack cross-section area; (3) The burner operating conditions (e.g., excess air, combustion air temperature, and so on). For furnaces or boilers using an induced-draft (ID) fan, the furnace negative pressure depends on the fan performance and frictional losses between the fan inlet and the point of air leakage. In most cases, it would be necessary to measure or estimate negative pressure at the opening. The amount of air leakage, the heat lost in flue gases, and their effects on increased furnace or boiler fuel consumption can be calculated by using the equations and graphs given in Industrial Furnaces (see W. Trinks et al., below). Note that the actual heat input required to compensate for the heat loss in flue gases due to air leakage would be greater than the heat contained in the air leakage because of the effect of available heat in the furnace. For a high-temperature furnace that is not maintained properly, the fuel consumption increase due to air leakage can be as high as 10% of the fuel input.

Not Available

2011-10-01T23:59:59.000Z

230

Louisiana Wetland Loss at Askives  

U.S. Energy Information Administration (EIA)

Louisiana Wetland Loss? - Find Questions and Answers at Askives, the first startup that gives you an straight answer

231

SPECIFIC HEAT INDICATOR  

DOE Patents (OSTI)

Apparatus for continuously and automatically measuring and computing the specific heat of a flowing solution is described. The invention provides for the continuous measurement of all the parameters required for the mathematical solution of this characteristic. The parameters are converted to logarithmic functions which are added and subtracted in accordance with the solution and a null-seeking servo reduces errors due to changing voltage drops to a minimum. Logarithmic potentiometers are utilized in a unique manner to accomplish these results.

Horn, F.L.; Binns, J.E.

1961-05-01T23:59:59.000Z

232

Control schemes for an industrial rotary calciner with a heat shield around the combustion zone  

SciTech Connect

Soda ash (sodium carbonate) is produced by calcining natural trona ore (sodium sesquicarbonate) in rotary calciners. Shell overheating, the consequent deformation of the calciner shell, and heat loss are frequently encountered problems during this operation. Installation of a concentric, metallic heat shield around the calciner`s combustion zone can help to reduce the shell temperature and recover some of the energy that would otherwise be lost. Another problem often encountered is the deterioration of product quality when the system inputs deviate from their design rates. A mathematical model of the calciner with a heat shield is used to design different control schemes in order to maintain the product quality. Performance of the designed control schemes is demonstrated via computer simulation.

Ciftci, S.; Kim, N.K. [Michigan Technological Univ., Houghton, MI (United States). Dept. of Chemical Engineering] [Michigan Technological Univ., Houghton, MI (United States). Dept. of Chemical Engineering

1999-03-01T23:59:59.000Z

233

Incentives for reducing emissions in Krakow  

SciTech Connect

This effort is identifying, specific incentives that may be used by Krakow city officials to encourage, residents to change the way they heat their homes and businesses in order to reduce pollution. This paper describes the incentives study for converting small coal or coke-fired boilers to gas in the Old Town area. A similar study looked at incentives for expanding the district heating system and future analyses will be performed for home stove options.

Uberman, R. [Polinvest Ltd., Krakow (Poland); Pierce, B. [Brookhaven National Lab., Upton, NY (United States); Lazecki, A. [Biuro Rozwoju Krakowa, Krakow (Poland)

1994-06-01T23:59:59.000Z

234

Waste heat recovery system having thermal sleeve support for heat pipe  

SciTech Connect

A system for recovering waste heat from a stream of heated gas is disclosed. The system includes a convection heat transfer chamber, a boiler tank, and a plurality of heat pipes thermally interconnecting the convection heat transfer chamber with the boiler tank. Each of the heat pipes includes an evaporator section which is disposed in heat transfer relation with a stream of heated gas flowing through the convection heat transfer chamber, and a condenser section disposed in heat transfer relation with a volume of water contained within the boiler tank. The boiler tank is provided with a header plate having an array of heat pipe openings through which the heat pipes project. A heat pipe support sleeve is received in each heat pipe opening in sealed engagement with the header plate, with the heat pipes projecting through the support sleeves and thermally interconnecting the convection heat transfer chamber with the boiler tank. An intermediate portion of each heat pipe is received in sealed engagement with its associated support sleeve. In a preferred embodiment, heat transfer through the support sleeve is minimized in an arrangement in which each heat pipe opening is reduced by a stepped bore with the support sleeve connected in threaded, sealed engagement with the stepped bore. Futhermore, in this arrangement, the support sleeve has swaged end portions which project beyond the header plate and engage the heat pipe on opposite sides at points which are remote with respect to the support sleeve/header plate interface. One of the swages end portions is sealed against the heat pipe in a fluid-tight union within the boiler tank. The support sleeve is radially spaced with respect to the heat pipe, and is also radially spaced with respect to the heat pipe opening whereby heat transfer through the walls of the heat pipe to the support sleeve and to the header plate is minimized by concentric annular air gaps.

McCurley, J.

1984-01-24T23:59:59.000Z

235

Waste heat recovery system having thermal sleeve support for heat pipe  

SciTech Connect

A system for recovering waste heat from a stream of heated gas is disclosed. The system includes a convection heat transfer chamber, a boiler tank, and a plurality of heat pipes thermally interconnecting the convection heat transfer chamber with the boiler tank. Each of the heat pipes includes an evaporator section which is disposed in heat transfer relation with a stream of heated gas flowing through the convection heat transfer chamber, and a condenser section disposed in heat transfer relation with a volume of water contained within the boiler tank. The boiler tank is provided with a header plate having an array of heat pipe openings through which the heat pipes project. A heat pipe support sleeve is received in each heat pipe opening in sealed engagement with the header plate, with the heat pipes projecting through the support sleeves and thermally interconnecting the convection heat transfer chamber with the boiler tank. An intermediate portion of each heat pipe is received in sealed engagement with its associated support sleeve. In a preferred embodiment, heat transfer through the support sleeve is minimized in an arrangement in which each heat pipe opening is reduced by a stepped bore with the support sleeve connected in threaded, sealed engagement with the stepped bore. Furthermore, in this arrangement, the support sleeve has swaged end portions which project beyond the header plate and engage the heat pipe on opposite sides at points which are remote with respect to the support sleeve/header plate interface. One of the swaged end portions is sealed against the heat pipe in a fluid-tight union within the boiler tank. The support sleeve is radially spaced with respect to the heat pipe, and is also radially spaced with respect to the heat pipe opening whereby heat transfer through the walls of the heat pipe to the support sleeve and to the header plate is minimized by concentric annular air gaps.

McCurley, J.

1984-04-10T23:59:59.000Z

236

Waste heat recovery system having thermal sleeve support for heat pipe  

SciTech Connect

A system for recovering waste heat from a stream of heated gas is disclosed. The system includes a convection heat transfer chamber, a boiler tank, and a plurality of heat pipes thermally interconnecting the convection heat transfer chamber with the boiler tank. Each of the heat pipes includes an evaporator section which is disposed in heat transfer relation with a stream of heated gas flowing through the convection heat transfer chamber, and a condenser section disposed in heat transfer relation with a volume of water contained within the boiler tank. The boiler tank is provided with a header plate having an array of heat pipe openings through which the heat pipes project. A heat pipe support sleeve is received in each heat pipe opening in sealed engagement with the header plate, with the heat pipes projecting through the support sleeves and thermally interconnecting the convection heat transfer chamber with the boiler tank. An intermediate portion of each heat pipe is received in sealed engagement with its associated support sleeve. In a preferred embodiment, heat transfer through the support sleeve is minimized in an arrangement in which each heat pipe opening is reduced by a stepped bore with the support sleeve connected in threaded, sealed engagement with the stepped bore. Furthermore, in this arrangement, the support sleeve has swaged end portions which project beyond the header plate and engage the heat pipe on opposite sides at points which are remote with respect to the support sleeve/header plate interface. One of the swaged end portions is sealed against the heat pipe in a fluid-tight union within the boiler tank. The support sleeve is radially spaced with respect to the heat pipe and is also radially spaced with respect to the heat pipe opening whereby heat transfer through the walls of the heat pipe to the support sleeve and to the header plate is minimized by concentric annular air gaps.

McCurley, J.

1984-12-04T23:59:59.000Z

237

Waste heat recovery system having thermal sleeve support for heat pipe  

SciTech Connect

A system for recovering waste heat from a stream of heated gas is disclosed. The system includes a convection heat transfer chamber, a boiler tank, and a plurality of heat pipes thermally interconnecting the convection heat transfer chamber with the boiler tank. Each of the heat pipes includes an evaporator section which is disposed in heat transfer relation with a stream of heated gas flowing through the convection heat transfer chamber, and a condenser section disposed in heat transfer relation with a volume of water contained within the boiler tank. The boiler tank is provided with a header plate having an array of heat pipe openings through which the heat pipes project. A heat support sleeve is received in each heat pipe opening in sealed engagement with the header plate, with the heat pipes projecting through the support sleeves and thermally interconnecting the convection heat transfer chamber with the boiler tank. An intermediate portion of each heat pipe is received in sealed engagement with its associated support sleeve. In a preferred embodiment, heat transfer through the support sleeve is minimized in an arrangement in which each heat pipe opening is reduced by a stepped bore with the support sleeve connected in threaded, sealed engagement with the stepped bore. Furthermore, in this arrangement, the support sleeve has swaged end portions which project beyond the header plate and engage the heat pipe on opposite sides at points which are remote with respect to the support sleeve/header plate interface. One of the swaged end portions is sealed against the heat pipe in a fluid-tight union within the boiler tank. The support sleeve is radially spaced with respect to the heat pipe, and is also radially spaced with respect to the heat pipe opening whereby heat transfer through the walls of the heat pipe to the support sleeve and to the header plate is minimized by concentric annular air gaps.

McCurley, J.

1984-12-18T23:59:59.000Z

238

HEAT GENERATION  

DOE Patents (OSTI)

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

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

1963-12-01T23:59:59.000Z

239

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

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

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

240

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

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

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

Note: This page contains sample records for the topic "reduce heat loss" 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

Comparative performance of two types of evacuated tube solar collectors in a residential heating and cooling system. The progress report  

DOE Green Energy (OSTI)

Two types of evacuated tube solar collectors have been operated in space heating, cooling and domestic hot water heating systems in Colorado State University Solar House I. An experimental collector from Corning Glass Works supplied heat to the system from January 1977 through February 1978, and an experimental collector from Philips Research Laboratory, Aachen, which is currently in use, has been operating since August 1978. A flat absorber plate inside a single-walled glass tube is used in the Corning design, whereas heat is conducted through a single glass wall to an external heat exchanger plate in the Philips collector. In comparison with conventional flat-plate collectors, both types show reduced heat losses and improved efficiency. For space heating and hot water supply in winter, the solar delivery efficiency of the Corning collector ranged from 49% to 60% of the incident solar energy. The portion of the space heating and domestic hot water load carried by solar energy through fall and winter ranged from 50% to 74%, with a four-month contribution of 61% of the total requirements. Data on the Philips collector are currently being analyzed.

Conway, T.M.; Duff, W.S.; Lof, G.O.G.; Pratt, R.G.

1979-01-01T23:59:59.000Z

242

Evaporation and condensation of spherical interstellar clouds. Self-consistent models with saturated heat conduction and cooling  

E-Print Network (OSTI)

Shortened version: The fate of IS clouds embedded in a hot tenuous medium depends on whether the clouds suffer from evaporation or whether material condensates onto them. Analytical solutions for the rate of evaporative mass loss from an isolated spherical cloud embedded in a hot tenuous gas are deduced by Cowie & McKee (1977). In order to test the validity of the analytical results for more realistic IS conditions the full hydrodynamical equations must be treated. Therefore, 2D numerical simulations of the evolution of IS clouds %are performed with different internal density structures and surrounded by a hot plasma reservoir. Self-gravity, interstellar heating and cooling effects and heat conduction by electrons are added. Classical thermal conductivity of a fully ionized hydrogen plasma and saturated heat flux are considered. Using pure hydrodynamics and classical heat flux we can reproduce the analytical results. Heat flux saturation reduces the evaporation rate by one order of magnitude below the analytical value. The evolution changes totally for more realistic conditions when interstellar heating and cooling effects stabilize the self-gravity. Evaporation then turns into condensation, because the additional energy by heat conduction can be transported away from the interface and radiated off efficiently from the cloud's inner parts. I.e. that the saturated heat flux consideration is inevitable for IS clouds embedded in hot tenuous gas. Various consequences are discussed in the paper.

W. Vieser; G. Hensler

2007-09-05T23:59:59.000Z

243

Sol-Clad-Siding and Trans-Lucent-Insulation : curtain wall components for conserving dwelling heat by passive-solar means  

E-Print Network (OSTI)

A prototype for a dwelling heat loss compensator is introduced in this thesis, along with its measured thermal performance and suggestions for its future development. As a heat loss compensator, the Sol-Clad-Siding collects, ...

Iliesiu, Doru

1983-01-01T23:59:59.000Z

244

Heat exchanger  

DOE Patents (OSTI)

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

Wolowodiuk, Walter (New Providence, NJ)

1976-01-06T23:59:59.000Z

245

Protected Loss of Flow Transient Simulation (Quicktime format, High  

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

Engineering Analysis > Videos Engineering Analysis > Videos Engineering Analysis: Protected Loss of Flow Transient Simulation Quicktime format Quicktime Format - High Bandwidth | Size: 25.94 MB | Bit Rate: 1148 kbps Keywords: flow transient, plot, EBR-II, SAS4A, SASSYS-1, passive safety, protected loss of flow, PLOF, shutdown heat removal test, SHRT-17, SHRT17 Elevation plot showing detailed top of core temperatures in experimental assembly XX09 during a protected loss of flow transient in EBR-II. Surrounding assemblies are depicted using fuel average temperatures. Results show excellent decay heat removal capability of sodium through natural circulation and exceptionally low transient temperatures with metallic fuel. :: Please wait until video loads completely :: Closed Captioning Transcript

246

Low Impact Weight Loss Exercises | Fish Oil Weight Loss  

U.S. Energy Information Administration (EIA)

Low Impact Weight Loss Exercises. You want to lose weight, but for whatever reason, you want to or only can perform low impact exercises. No problem.

247

Energy Basics: Absorption Heat Pumps  

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

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

248

Energy Basics: Geothermal Heat Pumps  

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

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

249

Performance analysis of dedicated heat-pump water heaters in an office building  

SciTech Connect

An evaluation is made of the performance of two generic dedicated heat pump water heaters (HPWHs) in supplying the domestic hot water (DHW) needs of a medium-sized office building in Colorado. Results are based on preliminary data measurements, and assumptions are made to compensate for a faulty flow meter. A stand-alone heat pump plumbed to a conventional tank obtains a coefficient of performance (COP) of 2.4 but only delivers load water temperatures of about 41/sup 0/C (105/sup 0/F) because of the 15,142 L/day (4000 gal/day) recirculating loop flow. An industrial-grade stand-alone HPWH will replace this unit. An integral heat pump/tank unit is being tested, but results are not available because of compressor starting problems. Recirculating loop losses account for 75% of the energy delivered by the HPWHs. These losses could be reduced by 75% if the recirculating loop were insulated, thus reducing the DHW fuel costs by 50%. The insulation expense could be paid in less than 3 years by savings in DHW fuel costs.

Morrison, L.

1981-05-01T23:59:59.000Z

250

Impact of magnetic field inhomogeneity on electron cyclotron radiative loss in tokamak reactors  

Science Conference Proceedings (OSTI)

The potential importance of electron cyclotron (EC) emission in the local electron power balance in the steady-state regimes of ITER operation with high temperatures, as well as in the DEMO reactor, requires accurate calculation of the one-dimensional (over magnetic surfaces) distribution of the net radiated power density, P{sub EC}({rho}). When the central electron temperature increases to {approx}30 keV, the local EC radiative loss comprises a substantial fraction of the heating power from fusion alphas and is close to the total auxiliary NBI heating power, P{sub EC}(0) Asymptotically-Equal-To 0.3P{sub {alpha}}(0) Asymptotically-Equal-To P{sub aux}(0). In the present paper, the model of EC radiative transport in an axisymmetric toroidal plasma is extended to the case of an inhomogeneous magnetic field B(R, Z). The impact of such inhomogeneity on local and total power losses is analyzed in the framework of this model by using the CYNEQ code. It is shown that, for the magnetic field B, temperature T{sub e}, density n{sub e}, and wall reflection coefficient R{sub w} expected in ITER and DEMO, accurate simulations of the EC radiative loss require self-consistent 1.5D transport analysis (i.e., one-dimensional simulations of plasma transport and two-dimensional simulations of plasma equilibrium). It is shown that EC radiative transport can be described with good accuracy in the 1D approximation with the surface-averaged magnetic field, B({rho}) = Left-Pointing-Angle-Bracket B(R, Z) Right-Pointing-Angle-Bracket {sub ms}. This makes it possible to substantially reduce the computational time required for time-dependent self-consistent 1.5D transport analysis. Benchmarking of the CYNEQ results with available results of the RAYTEC, EXACTEC, and CYTRAN codes is performed for various approximations of the magnetic field.

Kukushkin, A. B.; Minashin, P. V. [National Research Centre Kurchatov Institute, Tokamak Physics Institute (Russian Federation); Polevoi, A. R. [Route de Vinon sur Verdon, ITER Organization (France)

2012-03-15T23:59:59.000Z

251

Industrial Heat Pump Case Study  

E-Print Network (OSTI)

An open-cycle heat pump was retrofitted to a single-effect, recirculating-type evaporator used for reducing the water content of whey (a liquid by-product from cheese production). The purpose of the retrofit was to reduce the energy costs associated 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-up.) This concept is sometimes called mechanical vapor compression (MVC) or mechanical vapor recompression (MVR). A variety of engineering issues have to be resolved to integrate a heat pump into an evaporator system. This paper identifies key issues and describes how they were resolved for this particular process. Issues include choice of compressor, motor selection, control strategy, impact of heat pump on heat exchanger surface area requirements and related issues, and methods for protecting the compressor from surge, droplet ingestion, and other hazards.

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

1985-05-01T23:59:59.000Z

252

Heat Exchangers  

Science Conference Proceedings (OSTI)

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

253

ABSORPTION HEAT PUMP IN THE DISTRICT HEATING  

E-Print Network (OSTI)

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

Oak Ridge National Laboratory

254

Electrically heated liquid tank employing heat pipe heat transfer means  

SciTech Connect

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

Shutt, J.R.

1978-12-26T23:59:59.000Z

255

Energy Consumption and Demand as Affected by Heat Pumps that Cool, Heat and Heat Domestic Water  

E-Print Network (OSTI)

Products or systems that heat, cool and heat domestic water, which are also referred to as integrated systems, have been available for several years. The concept is simple and appeals to consumers. This paper presents methods for evaluating the potential savings by using an integrated system that heats water by desuperheating discharge gas in the refrigeration cycle. The methods may be applied for any specific location, and their accuracy will depend on the accuracy of building loads and water usage estimates. Power demand can also be affected by electric water heaters. The methods presented demonstrate how integrated systems can be of value in reducing daily summertime peaks.

Cawley, R.

1992-05-01T23:59:59.000Z

256

Definition: Ground Source Heat Pumps | Open Energy Information  

Open Energy Info (EERE)

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

257

Solar heat collector  

SciTech Connect

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

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

1984-04-03T23:59:59.000Z

258

Geothermal district heating systems  

DOE Green Energy (OSTI)

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

Budney, G.S.; Childs, F.

1982-01-01T23:59:59.000Z

259

Oblique inlet pressure loss for swirling flow entering a catalyst substrate  

Science Conference Proceedings (OSTI)

This experimental study investigates the oblique inlet pressure loss for the entry of an annular swirling flow into an automotive catalyst substrate. The results are applicable to a wide range of compact heat exchangers. For zero swirl, the total pressure loss agrees with established expressions for pressure loss in developing laminar flow in parallel channels with finite wall thickness. For positive swirl, the additional pressure loss due to oblique flow entry is correlated to the tangential velocity upstream of the catalyst, measured using laser-Doppler anemometry. The obtained oblique inlet pressure loss correlation can improve the accuracy of numerical calculations of the flow distribution in catalysts. (author)

Persoons, T.; Vanierschot, M.; Van den Bulck, E. [Katholieke Universiteit Leuven, Department of Mechanical Engineering, Celestijnenlaan 300A, B-3001 Leuven (Belgium)

2008-05-15T23:59:59.000Z

260

Experimental Analysis of Variable Capacity Heat Pump Systems equipped with a liquid-cooled frequency inverter.  

E-Print Network (OSTI)

?? Using an inverter-driven compressor in variable capacity heat pump systems has a main drawback, which is the extra loss in the inverter. The present… (more)

Ebraheem, Thair

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduce heat loss" 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

Colorado State University program for developing, testing, evaluating and optimizing solar heating and cooling systems  

DOE Green Energy (OSTI)

Results of heat loss tests for the Integral Collector Storage unit are shown. Work on unique solar system components is summarized briefly. (MHR)

Not Available

1993-06-01T23:59:59.000Z

262

A Better Steam Engine: Designing a Distributed Concentrating Solar Combined Heat and Power System  

E-Print Network (OSTI)

Vacuum tube liquid-vapor (heat-pipe) collectors. Proceedingsheat rejection in a condenser across a temperature gradient. This cycle ignores pressure losses in the pipes,

Norwood, Zachary Mills

2011-01-01T23:59:59.000Z

263

Forecasting photovoltaic array power production subject to mismatch losses  

Science Conference Proceedings (OSTI)

The development of photovoltaic (PV) energy throughout the world this last decade has brought to light the presence of module mismatch losses in most PV applications. Such power losses, mainly occasioned by partial shading of arrays and differences in PV modules, can be reduced by changing module interconnections of a solar array. This paper presents a novel method to forecast existing PV array production in diverse environmental conditions. In this approach, field measurement data is used to identify module parameters once and for all. The proposed method simulates PV arrays with adaptable module interconnection schemes in order to reduce mismatch losses. The model has been validated by experimental results taken on a 2.2 kW{sub p} plant, with three different interconnection schemes, which show reliable power production forecast precision in both partially shaded and normal operating conditions. Field measurements show interest in using alternative plant configurations in PV systems for decreasing module mismatch losses. (author)

Picault, D.; Raison, B.; Bacha, S. [Grenoble Electrical Engineering Laboratory (G2Elab), 961, rue Houille Blanche BP 46, 38402 St Martin d'Heres (France); de la Casa, J.; Aguilera, J. [Grupo de Investigacion IDEA, Departamento de Electronica, Escuela Politecnica Superior, Universidad de Jaen, Campus Las Lagunillas, 23071 Jaen (Spain)

2010-07-15T23:59:59.000Z

264

Potential energy savings based on reduction of pressure in Central Heating System  

Science Conference Proceedings (OSTI)

Methodology and practical recommendations on retrofitting existing Central Heating Systems to deliver steam at lower pressure are presented. The retrofitting, is examined in terms of engineering approaches and economic effectiveness. In addition to investigating the savings obtainable through reduction of thermal and leakage losses, other energy conservation opportunities related to reduction of steam pressure are considered. The latter includes less boiler blowdown, less energy used pumping feedwater, less steam vented from the deaerator, reduced boiler maintenance and repair requirements, and cogeneration of electricity by steam or gas turbines. Energy savings are estimated as up to 10%, and payback period as in the range of two to four years.

Minkov, V.; Hirsch, P.

1984-08-01T23:59:59.000Z

265

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

266

Heat pump system  

DOE Patents (OSTI)

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

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

1979-01-01T23:59:59.000Z

267

Energy Basics: Radiant Heating  

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

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

268

Energy Basics: Radiant Heating  

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

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

269

Investigating potential light-duty efficiency improvements through simulation of turbo-compounding and waste-heat recovery systems  

Science Conference Proceedings (OSTI)

Modern diesel engines used in light-duty transportation applications have peak brake thermal efficiencies in the range of 40-42% for high-load operation with substantially lower efficiencies at realistic road-load conditions. Thermodynamic energy and exergy analysis reveals that the largest losses from these engines are due to combustion irreversibility and heat loss to the coolant, through the exhaust, and by direct convection and radiation to the environment. Substantial improvement in overall engine efficiency requires reducing or recovering these losses. Unfortunately, much of the heat transfer either occurs at relatively low temperatures resulting in large entropy generation (such as in the air-charge cooler), is transferred to low-exergy flow streams (such as the oil and engine coolant), or is radiated or convected directly to the environment. While there are significant opportunities for recovery from the exhaust and EGR cooler for heavy-duty applications, achieving similar benefits for light-duty applications is complicated by transient, low-load operation at typical driving conditions and competition with the turbocharger and aftertreatment system for the limited thermal resources. We have developed an organic Rankine cycle model using GT-Suite to investigate the potential for efficiency improvement through waste-heat recovery from the exhaust and EGR cooler of a light-duty diesel engine. The model is used to examine the effects of efficiency-improvement strategies such as cylinder deactivation, use of advanced materials and improved insulation to limit ambient heat loss, and turbo-compounding on the steady-state performance of the ORC system and the availability of thermal energy for downstream aftertreatment systems. Results from transient drive-cycle simulations are also presented, and we discuss strategies to address operational difficulties associated with transient drive cycles and balancing the thermal requirements of waste-heat recovery, turbocharging or turbo-compounding, and exhaust aftertreatment.

Edwards, Kevin Dean [ORNL; Wagner, Robert M [ORNL; Briggs, Thomas E [ORNL

2010-01-01T23:59:59.000Z

270

Increasing Energy Efficiency and Reducing Emissions from China's Cement Kilns: Audit Report of Two Cement Plants in Shandong Province, China  

E-Print Network (OSTI)

dryer that uses heat from boiler exhaust gases to reduce thedrying coal in heat recovery boilers to raise steam, and forup to 6 MW power. The boilers use the heat of exhaust gases

Price, Lynn

2013-01-01T23:59:59.000Z

271

Plate Fin Heat Exchanger Model with Axial Conduction and Variable Properties  

Science Conference Proceedings (OSTI)

Future superconducting radio frequency (SRF) cavities, as part of Project X at Fermilab, will be cooled to superfluid helium temperatures by a cryogenic distribution system supplying cold supercritical helium. To reduce vapor fraction during the final Joule-Thomson (J-T) expansion into the superfluid helium cooling bath, counter-flow, plate-fin heat exchangers will be utilized. Due to their compact size and ease of fabrication, plate-fin heat exchangers are an effective option. However, the design of compact and high-effectiveness cryogenic heat exchangers operating at liquid helium temperatures requires consideration of axial heat conduction along the direction of flow, in addition to variable fluid properties. Here we present a numerical model that includes the effects of axial conduction and variable properties for a plate fin heat exchanger. The model is used to guide design decisions on heat exchanger material choice and geometry. In addition, the J-T expansion process is modeled with the heat exchanger to analyze the effect of heat load and cryogenic supply parameters. A numerical model that includes the effects of axial conduction and variable properties for a plate fin heat exchanger was developed and the effect of various design parameters on overall heat exchanger size was investigated. It was found that highly conductive metals should be avoided in the design of compact JT heat exchangers. For the geometry considered, the optimal conductivity is around 3.5 W/m-K and can range from 0.3-10 W/m-K without a large loss in performance. The model was implemented with an isenthalpic expansion process. Increasing the cold side inlet temperature from 2K to 2.2 K decreased the liquid fraction from 0.856 to 0.839 which corresponds to a 0.12 g/s increase in supercritical helium supply needed to maintain liquid level in the cooling bath. Lastly, it was found that the effectiveness increased when the heat load was below the design value. Therefore, the heat exchanger should be sized on the high end of the required heat load.

Hansen, B.J.; White, M.J.; Klebaner, A.; /Fermilab

2011-06-10T23:59:59.000Z

272

Heat transfer and heat exchangers reference handbook  

Science Conference Proceedings (OSTI)

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

Not Available

1991-01-15T23:59:59.000Z

273

Heating systems for heating subsurface formations  

Science Conference Proceedings (OSTI)

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

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

2011-04-26T23:59:59.000Z

274

A desiccant dehumidifier for electric vehicle heating  

DOE Green Energy (OSTI)

Vehicle heating requires a substantial amount of energy. Engines in conventional cars produce enough waste heat to provide comfort heating and defogging/defrosting, even under very extreme conditions. Electric vehicles (EVs), however, generate little waste heat. Using battery energy for heating may consume a substantial fraction of the energy storage capacity, reducing the vehicle range, which is one of the most important parameters in determining EV acceptability. Water vapor generated by the vehicle passengers is in large part responsible for the high heating loads existing in vehicles. In cold climates, the generation of water vapor inside the car may result in water condensation on the windows, diminishing visibility. Two strategies are commonly used to avoid condensation on windows: windows are kept warm, and a large amount of ambient air is introduced in the vehicle. Either strategy results in a substantial heating load. These strategies are often used in combination, and a trade-off exists between them. If window temperature is decreased, ventilation rate has to be increased. Reducing the ventilation rate requires an increase of the temperature of the windows to prevent condensation. An alternative solution is a desiccant dehumidifier, which adsorbs water vapor generated by the passengers. Window temperatures and ventilation rates can then be reduced, resulting in a substantially lower heating load. This paper explores the dehumidifier heating concept. The first part shows the energy savings that could be obtained by using this technology. The second part specifies the required characteristics and dimensions of the system. The results indicate that the desiccant system can reduce the steady-state heating load by 60% or more under typical conditions. The reduction in heating load is such that waste heat may be enough to provide the required heating under most ambient conditions. Desiccant system dimensions and weight appear reasonable for packaging in an EV.

Aceves, S.M.; Smith, J.R.

1996-09-01T23:59:59.000Z

275

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

276

FS: heat pump water heaters | The Better Buildings Alliance  

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

Food Service » Install a heat pump Food Service » Install a heat pump water heaterand reduce water heating energy up to 70% using the commercial heat pump water heater specificat Activities Technology Solutions Teams Lighting & Electrical Space Conditioning Plug & Process Loads Food Service Refrigeration Laboratories Energy Management & Information Systems Public Sector Teams Market Solutions Teams Install a heat pump water heaterand reduce water heating energy up to 70% using the commercial heat pump water heater specification The Food Service team developed a Commercial Heat Pump Water Heater Specification that can be used to reduce water heating energy by 70%. An older, electric resistance water heater (operated in a building with a hot water demand of 500 gallons a day) can cost more than $3,500 each year

277

Radiofrequency plasma heating: proceedings  

SciTech Connect

The conference proceedings include sessions on Alfven Wave Heating, ICRF Heating and Current Drive, Lower Hybrid Heating and Current Drive, and ECRF Heating. Questions of confinement, diagnostics, instabilities and technology are considered. Individual papers are cataloged separately. (WRF)

Swenson, D.G. (ed.)

1985-01-01T23:59:59.000Z

278

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

SciTech Connect

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

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

1993-04-01T23:59:59.000Z

279

Heat Pipe Technology for Energy Conservation in the Process Industry  

E-Print Network (OSTI)

Many applications for heat pipe technology have emerged in the relatively short time this technology has been known. Heat pipes incorporated in heat exchangers have been used in tens of thousands of successful heat recovery systems. These systems range from residential and commercial air-to-air heat exchangers to giant air preheaters for the process and utility industries. The heat pipe offers a unique, efficient heat transfer device that can recover valuable thermal energy resulting in reduced equipment and operating costs. Q-dot is the world leader in heat pipe technology and we have applied our expertise in engineering heat recovery products for the process industry. This paper discusses two such products, the heat pipe air preheater and waste heat recovery boiler. These heat pipe products have been used in many successful installations all over the world and some important, distinctive features of these systems will be presented.

Price, B. L. Jr.

1985-05-01T23:59:59.000Z

280

Beam heating of target foils  

SciTech Connect

A target rotator, built to reduce the effects of beam spot heating, is fully adjustable, holds three targets, is chamber independent, and takes up limited space. The expected temperature rise in the target is calculated from the Stefan--Boltzmann law. (PMA)

Corwin, W.C.

1975-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduce heat loss" 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

Low Temperature Heat Recovery for Boiler Systems  

E-Print Network (OSTI)

Low temperature corrosion proof heat exchangers designed to reduce boiler flue gas temperatures to 150°F or lower are now being commercially operated on gas, oil and coal fired boilers. These heat exchangers, when applied to boiler flue gas, are commonly called condensing economizers. It has traditionally been common practice in the boiler industry to not reduce flue gas temperatures below the 300°F to 400°F range. This barrier has now been broken by the development and application of corrosion proof heat exchanger technology. This opens up a vast reservior of untapped recoverable energy that can be recovered and reused as an energy source. The successful recovery of this heat and the optimum use of it are the fundemental goals of the technology presented in this paper. This Recovered Low Level Heat Is Normally Used To Heat Cold Make-up Water Or Combustion Air.

Shook, J. R.; Luttenberger, D. B.

1986-06-01T23:59:59.000Z

282

A quantitative design and analysis of magnetic nanoparticle heating systems  

E-Print Network (OSTI)

Magnetic particles under the influence of an alternating magnetic field act as localized heating sources due to various loss mechanisms. This effect has been extensively investigated in hypothermia studies over the past ...

Khushrushahi, Shahriar Rohinton

2006-01-01T23:59:59.000Z

283

Remote Measurement of Heat Flux from Power Plant Cooling Lakes  

Science Conference Proceedings (OSTI)

Laboratory experiments have demonstrated a correlation between the rate of heat loss q? from an experimental fluid to the air above and the standard deviation ? of the thermal variability in images of the fluid surface. These experimental results ...

Alfred J. Garrett; Robert J. Kurzeja; Eliel Villa-Aleman; James S. Bollinger; Malcolm M. Pendergast

2013-06-01T23:59:59.000Z

284

Microwave Heating, Energy and Environment - Programmaster.org  

Science Conference Proceedings (OSTI)

Mar 7, 2013 ... Microwave Reflection Loss of Ferric Oxide: Zhiwei Peng1; ... heat rapidly by microwave (MW) irradiation generating plasma during oxidation of surfaces. .... Co-Gasification Behavior of Metallurgical Coke with High and Low ...

285

Photovoltaic roof heat flux  

E-Print Network (OSTI)

and could the heat transfer processes be modeled to estimateindicating that the heat transfer processes were modeled w i

Samady, Mezhgan Frishta

2011-01-01T23:59:59.000Z

286

Error Analysis of Heat Transfer for Finned-Tube Heat-Exchanger Text-Board  

E-Print Network (OSTI)

In order to reduce the measurement error of heat transfer in water and air side for finned-tube heat-exchanger as little as possible, and design a heat-exchanger test-board measurement system economically, based on the principle of test-board system error analyses and design, the equation of measurement error of heat transfer in air side and water side about orifice meter for the finned-tube heat-exchanger was obtained. This paper studies the major factors that may influence the largest admitted measurement error of measurement instruments for heat transfer in water and air side, and analyzes the degree that water temperature and pressure measurement influence heat transfer in water side, and the degree that wet bulb temperature difference measurement influences heat transfer in air side. Finally, this paper indicates that the key problem of reducing heat transfer in water side is water temperature measurement of the in-out pipe of heat-exchanger, and wet bulb temperature difference is a key to decrease the heat transfer in air side for finned-tube heat-exchanger. This paper gives a theoretical instruction for designing the measurement system of a finned-tube heat-exchanger test-board

Chen, Y.; Zhang, J.

2006-01-01T23:59:59.000Z

287

heating | OpenEI Community  

Open Energy Info (EERE)

heating heating Home Dc's picture Submitted by Dc(15) Member 15 November, 2013 - 13:26 Living Walls ancient building system architect biomimicry building technology cooling cu daylight design problem energy use engineer fred andreas geothermal green building heat transfer heating living walls metabolic adjustment net zero pre-electricity Renewable Energy Solar university of colorado utility grid Wind Much of the discussion surrounding green buildings centers around reducing energy use. The term net zero is the platinum standard for green buildings, meaning the building in question does not take any more energy from the utility grid than it produces using renewable energy resources, such as solar, wind, or geothermal installations (and sometimes these renewable energy resources actually feed energy back to the utility grid).

288

Increasing Energy Efficiency and Reducing Emissions from China's Cement Kilns: Audit Report of Two Cement Plants in Shandong Province, China  

E-Print Network (OSTI)

further recover or reduce wasted energy. Exhaust air (gases)Energy use for the system can be reduced by analyzing how much heat is wasted

Price, Lynn

2013-01-01T23:59:59.000Z

289

Heat pipe methanator  

DOE Patents (OSTI)

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

Ranken, William A. (Los Alamos, NM); Kemme, Joseph E. (Los Alamos, NM)

1976-07-27T23:59:59.000Z

290

Heat reclaimer for a heat pump  

Science Conference Proceedings (OSTI)

This invention relates to a heat reclaiming device for a heat pump. The heat reclaimer is able to absorb heat from the compressor by circulating cooling fluid through a circuit which is mounted in good heat transfer relationship with the condenser, then around the shell of the motor-compressor and lastly around the hollow tube which connects the condenser to the compressor. The reclaiming circuit is connected into a fluid circulating loop which is used to supply heat to the evaporator coil of the heat pump.

Beacham, W.H.

1981-02-03T23:59:59.000Z

291

Minimize Boiler Short Cycling Losses  

SciTech Connect

This revised ITP tip sheet on minimizing boiler short cycling losses provides how-to advice for improving industrial steam systems using low-cost, proven practices and technologies.

2006-01-01T23:59:59.000Z

292

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

293

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

294

Swimming Pool Heating | Department of Energy  

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

reduce the cost of heating your swimming pool by installing a high-efficiency or solar heater, using a pool cover, managing the water temperature, and using a smaller pump less...

295

"Heat Exchange Enhancing Insert" Inventors .--.. Andrei Khodak...  

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

on the wall surface allowing heat transfer intensification. The shape of the device is created in a way that reduces overall hydraulic resistance to the insert. No.: M-856...

296

Heat pipe dehumidification for supermarket energy savings  

E-Print Network (OSTI)

This thesis examines the possibility of using a heat pipe installed in the air conditioning unit of a supermarket to increase the level of dehumidification of the inside air. This dehumidification is expected to reduce the ...

Oliver, Eric M. (Eric Michael)

1994-01-01T23:59:59.000Z

297

The Economics of Steam Vs. Electric Pipe Heating  

E-Print Network (OSTI)

To properly design a pipe heating system, the basic principles of heat transfer from an insulated pipe must be understood. The three methods of heat flow are conduction, convection (both forced and natural) and radiation. The total heat loss from a pipe must be determined first, since this is the heat which must be replaced to maintain a pipe at a given temperature. A steam heating system requires an analysis of the heat loss from the pipe as well as an analysis of the capacity of the heating system. The economics of steam heat include the accessories as well as the inefficiencies of steam heat. The design of an electric heating system normally involves far fewer components and engineering complexities than does a comparable steam system. The basic system is comprised of the heater, controls and connection accessories. Today there are several economic trade-offs to be made in selecting a pipe heating system. These involve engineering and design costs, maintenance costs, installation costs and energy costs. The economic trade-offs to be made in selecting a pipe heating system do not universally favor one system over another for all cases.

Schilling, R. E.

1985-05-01T23:59:59.000Z

298

ICRF heating on helical devices  

SciTech Connect

Ion cyclotron range of frequency (ICRF) heating is currently in use on CHS and W7AS and is a major element of the heating planned for steady state helical devices. In helical devices, the lack of a toroidal current eliminates both disruptions and the need for ICRF current drive, simplifying the design of antenna structures as compared to tokamak applications. However the survivability of plasma facing components and steady state cooling issues are directly applicable to tokamak devices. Results from LHD steady state experiments should be available on a time scale to strongly influence the next generation of steady state tokamak experiments. The helical plasma geometry provides challenges not faced with tokamak ICRF heating, including the potential for enhanced fast ion losses, impurity accumulation, limited access for antenna structures, and open magnetic field lines in the plasma edge. The present results and near term plans provide the basis for steady state ICRF heating of larger helical devices. An approach which includes direct electron, mode conversion, ion minority and ion Bernstein wave heating addresses these issues.

Rasmussen, D.A.; Lyon, J.F.; Hoffman, D.J. [and others

1995-09-01T23:59:59.000Z

299

ICRF heating on helical devices  

SciTech Connect

Ion cyclotron range of frequency (ICRF) heating is currently in use on CHS and W7-AS and is a major element of the heating planned for steady state helical devices. In helical devices, the lack of a toroidal current eliminates both disruptions and the need for ICRF current drive, simplifying the design of antenna structures as compared to tokamak applications. However the survivability of plasma facing components and steady state cooling issues are directly applicable to tokamak devices. Results from LHD steady state experiments should be available on a time scale to strongly influence the next generation of steady state tokamak experiments. The helical plasma geometry provides challenges not faced with tokamak ICRF heating, including the potential for enhanced fast ion losses, impurity accumulation, limited access for antenna structures, and open magnetic field lines in the plasma edge. The present results and near term plans provide the basis for steady state ICRF heating of larger helical devices. An approach which includes direct electron, mode conversion, ion minority and ion Bernstein wave heating addresses these issues.

Rasmussen, D.A.; Lyon, J.F.; Hoffman, D.J.; Murakami, M.; England, A.C.; Wilgen, J.B.; Jaeger, E.F.; Wang, C.; Batchelor, D.B.

1995-09-01T23:59:59.000Z

300

Enhanced heat transfer for thermionic power modules  

DOE Green Energy (OSTI)

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

Johnson, D.C.

1981-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduce heat loss" 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

Heating & Cooling | Department of Energy  

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

Cooling Cooling Heating & Cooling Heating and cooling account for about 56% of the energy use in a typical U.S. home, making it the largest energy expense for most homes. Learn more about the principles of heating and cooling. Heating and cooling account for about 56% of the energy use in a typical U.S. home, making it the largest energy expense for most homes. Learn more about the principles of heating and cooling. Did you know that heating and cooling accounts for more than half of the energy use in a typical U.S. home, making it the largest energy expense for most homes? Energy Saver shares tips and advice on ways you can reduce your heating and cooling costs, putting more money in your wallet.

302

Heat Recovery from the Exhaust Gas of Aluminum Reduction Cells  

Science Conference Proceedings (OSTI)

Increased Energy Efficiency and Reduced HF Emissions with New Heat Exchanger · Industrial Test of Low-voltage Energy-saving Aluminum Reduction ...

303

Energy Saving Absorption Heat Pump Water Heater - Energy ...  

ORNL’s new absorption heat pump and water heater technology offers substantial energy savings and can reduce the use of fossil fuels by buildings. While ...

304

Northeast Home Heating Oil Reserve now focuses on New England ...  

U.S. Energy Information Administration (EIA)

The Northeast Home Heating Oil Reserve (NHHOR) will be reduced to one million barrels, half its original size, as the stockpile's holdings are converted to ultra-low ...

305

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

Science Conference Proceedings (OSTI)

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

Wang Jinggang; Gao Xiaoxia; Yin Zhenjiang; Li Fang

2009-07-01T23:59:59.000Z

306

Reducing waste, Photoby stcvcchan  

E-Print Network (OSTI)

I ' I I t Reducing waste, Photoby stcvcchan AMs President Mike Lee (left to right), Point Grey M U recycling given high priority on campus By GAVIN WILSON UBC is taking stepsto reduce waste and encourageGellatly,Vice-President,Administration and Finance,to develop and recommend university policies on waste recycling. Another task force has submitted

Farrell, Anthony P.

307

Novel heat pipe combination  

SciTech Connect

The basic heat pipe principle is employed in a heat pipe combination wherein two heat pipes are combined in opposing relationship to form an integral unit; such that the temperature, heat flow, thermal characteristics, and temperature-related parameters of a monitored environment or object exposed to one end of the heat pipe combination can be measured and controlled by controlling the heat flow of the opposite end of the heat pipe combination.

Arcella, F.G.

1978-01-10T23:59:59.000Z

308

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

SciTech Connect

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

Edwards, Kevin Dean [ORNL; Wagner, Robert M [ORNL

2010-01-01T23:59:59.000Z

309

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

310

Heat pipes for use in a magnetic field  

DOE Patents (OSTI)

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

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

1981-04-29T23:59:59.000Z

311

Heat pipes for use in a magnetic field  

DOE Patents (OSTI)

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

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

1983-01-01T23:59:59.000Z

312

Development of an integrated building load-ground source heat pump model as a test bed to assess short- and long-term heat pump and ground loop performance.  

E-Print Network (OSTI)

??Ground source heat pumps (GSHP) have the ability to significantly reduce the energy required to heat and cool buildings. Historically, deployment of GSHP's in the… (more)

Gaspredes, Jonathan Louis

2012-01-01T23:59:59.000Z

313

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

314

Vision Loss: Visual Impairment and Vision Impairment | Department of Energy  

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

Vision Loss: Visual Impairment and Vision Impairment Vision Loss: Visual Impairment and Vision Impairment Vision Loss: Visual Impairment and Vision Impairment Visual impairment or vision impairment is vision loss that constitutes a significant limitation of visual capability resulting from disease, trauma, or a congenital or degenerative condition that cannot be corrected by conventional means, including refractive correction, medication, or surgery. Low Vision Anyone with non-correctable reduced vision is considered to be visually impaired, and can have a wide range of causes. Blindness Blindness is the condition of lacking visual perception due to physiological or psychological factors. Hearing Impairment Hearing impairment is a full or partial decrease in the ability to detect or understand sounds. Losing the ability to detect some frequencies, or

315

Reduced Thermal Conductivity of Compacted Silicon Nanowires  

E-Print Network (OSTI)

Nanoscale Heat Transfer Processes …. ………………………………. 7 1.4:1.3 – Nanoscale Heat Transfer Processes When studying heat

Yuen, Taylor S.

316

Carbon footprints of heating oil and LPG heating systems  

SciTech Connect

For European homes without access to the natural gas grid, the main fuels-of-choice for heating are heating oil and LPG. How do the carbon footprints of these compare? Existing literature does not clearly answer this, so the current study was undertaken to fill this gap. Footprints were estimated in seven countries that are representative of the EU and constitute two-thirds of the EU-27 population: Belgium, France, Germany, Ireland, Italy, Poland and the UK. Novelties of the assessment were: systems were defined using the EcoBoiler model; well-to-tank data were updated according to most-recent research; and combustion emission factors were used that were derived from a survey conducted for this study. The key finding is that new residential heating systems fuelled by LPG are 20% lower carbon and 15% lower overall-environmental-impact than those fuelled by heating oil. An unexpected finding was that an LPG system's environmental impact is about the same as that of a bio heating oil system fuelled by 100% rapeseed methyl ester, Europe's predominant biofuel. Moreover, a 20/80 blend (by energy content) with conventional heating oil, a bio-heating-oil system generates a footprint about 15% higher than an LPG system's. The final finding is that fuel switching can pay off in carbon terms. If a new LPG heating system replaces an ageing oil-fired one for the final five years of its service life, the carbon footprint of the system's final five years is reduced by more than 50%.

Johnson, Eric P., E-mail: ejohnson@ecosite.co.uk

2012-07-15T23:59:59.000Z

317

Reduce Oil Dependence Costs  

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

Reduce Oil Dependence Costs U.S. Petroleum Use, 1970-2010 Nearly 40% of the oil we use is imported, costing us roughly 300 billion annually. Increased domestic oil production from...

318

Overview of NASA supported Stirling thermodynamic loss research  

DOE Green Energy (OSTI)

The National Aeronautics and Space Administration (NASA) is funding research to characterize Stirling machine thermodynamic losses. NASA`s primary goal is to improve Stirling design codes to support engine development for space and terrestrial power. However, much of the fundamental data is applicable to Stirling cooler and heat pump applications. The research results are reviewed. Much has been learned about oscillating-flow hydrodynamics, including laminar/turbulent transition, and tabulated data has been documented for further analysis. Now, with a better understanding of the oscillator-flow field, it is time to begin measuring the effects of oscillating flow and oscillating pressure level on heat transfer in heat exchanger flow passages and in cylinders. This critical phase of the work is just beginning.

Tew, R.C.; Geng, S.M.

1994-09-01T23:59:59.000Z

319

Paving materials for heat island mitigation  

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

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

320

Reducing Diesel Engine Emissions  

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

Reducing Reducing Diesel Engine Emissions 2 0 1 0 Green TransporTaTion TechnoloGies Compared to traditional gasoline engines, diesel engines require less maintenance, generate energy more efficiently, and produce less carbon dioxide emissions. But when uncontrolled, diesel engines churn out harmful emissions like particu- late matter (PM) and nitrogen oxides (NO x ). Researchers at Argonne National Laboratory are currently working to develop

Note: This page contains sample records for the topic "reduce heat loss" 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

Industrial Waste Heat Recovery Using Heat Pipes  

E-Print Network (OSTI)

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

Ruch, M. A.

1981-01-01T23:59:59.000Z

322

Heat Recovery Steam Generator (HRSG) Chemical Cleaning Guidelines Case Studies  

Science Conference Proceedings (OSTI)

A considerable number of combined cycle units with heat recovery steam generators (HRSGs) were installed over the past two decades worldwide, and the design complexity and operating pressures of these units increased significantly during this period. One of the goals of EPRI's Heat Recovery Steam Generator (HRSG) Dependability Program 88 is to minimize availability losses associated with HRSG tube failures. To support its members operating combined cycle units, EPRI published Heat Recovery Steam Generato...

2006-11-13T23:59:59.000Z

323

Absorptive Recycle of Distillation Waste Heat  

E-Print Network (OSTI)

When the heat source available to a distillation process is at a significantly higher temperature than the reboiler temperature, there is unused availability (ability to perform work) in the heat supplied to the reboiler. Similarly, if the reflux 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, conserve) up to 50% of the required distillation energy. In contrast to compressor driven heat pumps, this savings is accomplished without need for a separate substantial input of mechanical power. A different AHP configuration is used depending on whether the excess availability is in the source heat or reject heat. In the excessive source temperature case, the higher temperature source heat is applied to the AHP, which then supplies the total reboiler requirement and recycles half the reject heat, with the remainder being rejected conventionally. In the excessive reject temperature case, all the reject heat is supplied to a reverse absorption heat pump (HAHP) which recycles half to reboiler temperature while reducing the remainder to ambient temperature.

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

1982-01-01T23:59:59.000Z

324

ORNL rod-bundle heat-transfer test data. Volume 6. Thermal-hydraulic test facility experimental data report for test 3. 05. 5B - double-ended cold-leg break simulation  

SciTech Connect

Thermal-Hydraulic Test Facility (THTF) Test 3.05.5B was conducted by members of the ORNL PWR Blowdown Heat Transfer Separate-Effects Program on July 3, 1980. The objective of the program is to investigate heat transfer phenomena believed to occur in PWRs during accidents, including small and large break loss-of-coolant accidents. Test 3.05.5B was designed to provide transient thermal-hydraulics data in rod bundle geometry under reactor accident-type conditions. Reduced instrument responses are presented. Also included are uncertainties in the instrument responses, calculated mass flows, and calculated rod powers.

Mullins, C.B.; Felde, D.K.; Sutton, A.G.; Gould, S.S.; Morris, D.G.; Robinson, J.J.; Schwinkendorf, K.N.

1982-05-18T23:59:59.000Z

325

Geothermal Heat Pumps  

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

Geothermal heat pumps use the constant temperature of the earth as an exchange medium for heat. Although many parts of the country experience seasonal temperature extremes—from scorching heat in...

326

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

327

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

328

SMALL PARTICLE HEAT EXCHANGERS  

E-Print Network (OSTI)

ON ~m Small Particle Heat Exchangers Arion J. Hunt June 1978d. LBL 7841 Small Particle Heat Exchangers by Arlon J. Huntgenerally to non-solar heat exchangers. These may be of the

Hunt, A.J.

2011-01-01T23:59:59.000Z

329

Heat Pump Systems  

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

Like a refrigerator, heat pumps use electricity to move heat from a cool space into a warm space, making the cool space cooler and the warm space warmer. Because they move heat rather than generate...

330

Photovoltaic roof heat flux  

E-Print Network (OSTI)

of ~24°C, indicating that heat conduction was small. T h i sday, indicating large heat conduction a n d storage. Control2.1.3 showed that conduction heat flux through the roof was

Samady, Mezhgan Frishta

2011-01-01T23:59:59.000Z

331

TRANSPARENT HEAT MIRRORS FOR PASSIVE SOLAR HEATING APPLICATIONS  

E-Print Network (OSTI)

for Passive Passive Solar Heating Applications StephenHEAT MIRRORS FOR PASSIVE SOLAR HEATING APPLICATIONS StephenMIRRORS FOR PASSIVE SOLAR HEATING APPLICATIONS Stephen

Selkowitz, S.

2011-01-01T23:59:59.000Z

332

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...

333

Midland District Heating District Heating Low Temperature Geothermal...  

Open Energy Info (EERE)

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

334

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

Open Energy Info (EERE)

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

335

San Bernardino District Heating District Heating Low Temperature...  

Open Energy Info (EERE)

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

336

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...

337

Pagosa Springs District Heating District Heating Low Temperature...  

Open Energy Info (EERE)

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

338

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

Open Energy Info (EERE)

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

339

Northeast Home Heating Oil Reserve System Heating Oil, PIA Office...  

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

Northeast Home Heating Oil Reserve System Heating Oil, PIA Office of Fossil Energy Headquaters Northeast Home Heating Oil Reserve System Heating Oil, PIA Office of Fossil Energy...

340

On the Role of Eddies and Surface Forcing in the Heat Transport and Overturning Circulation in Marginal Seas  

Science Conference Proceedings (OSTI)

The factors that determine the heat transport and overturning circulation in marginal seas subject to wind forcing and heat loss to the atmosphere are explored using a combination of a high-resolution ocean circulation model and a simple ...

Michael A. Spall

2011-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduce heat loss" 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

Calorimetric method of ac loss measurement in a rotating magnetic field  

Science Conference Proceedings (OSTI)

A method is described for calorimetric ac-loss measurements of high-T{sub c} superconductors (HTS) at 80 K. It is based on a technique used at 4.2 K for conventional superconducting wires that allows an easy loss measurement in parallel or perpendicular external field orientation. This paper focuses on ac loss measurement setup and calibration in a rotating magnetic field. This experimental setup is to demonstrate measuring loss using a temperature rise method under the influence of a rotating magnetic field. The slight temperature increase of the sample in an ac-field is used as a measure of losses. The aim is to simulate the loss in rotating machines using HTS. This is a unique technique to measure total ac loss in HTS at power frequencies. The sample is mounted on to a cold finger extended from a liquid nitrogen heat exchanger (HEX). The thermal insulation between the HEX and sample is provided by a material of low thermal conductivity, and low eddy current heating sample holder in vacuum vessel. A temperature sensor and noninductive heater have been incorporated in the sample holder allowing a rapid sample change. The main part of the data is obtained in the calorimetric measurement is used for calibration. The focus is on the accuracy and calibrations required to predict the actual ac losses in HTS. This setup has the advantage of being able to measure the total ac loss under the influence of a continuous moving field as experienced by any rotating machines.

Ghoshal, P. K. [Oxford Instruments NanoScience, Abingdon, Oxfordshire OX13 5QX (United Kingdom); Coombs, T. A.; Campbell, A. M. [Department of Engineering, Electrical Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom)

2010-07-15T23:59:59.000Z

342

Energy Loss by Breaking waves  

Science Conference Proceedings (OSTI)

Observations of the frequency of wind wave breaking in deep water are combined with laboratory estimates of the rate of energy loss a from single breaking wave to infer the net rate of energy transfer to the mixed layer from breaking waves, as a ...

S. A. Thorpe

1993-11-01T23:59:59.000Z

343

Definition: Reduced Co2 Emissions | Open Energy Information  

Open Energy Info (EERE)

Co2 Emissions Co2 Emissions Jump to: navigation, search Dictionary.png Reduced Co2 Emissions Functions that provide this benefit can lead to avoided vehicle miles, decrease the amount of central generation needed to their serve load (through reduced electricity consumption, reduced electricity losses, more optimal generation dispatch), and or reduce peak generation. These impacts translate into a reduction in CO2 emissions produced by fossil-based electricity generators and vehicles.[1] Related Terms electricity generation, reduced electricity losses, smart grid References ↑ SmartGrid.gov 'Description of Benefits' An in LikeLike UnlikeLike You like this.Sign Up to see what your friends like. line Glossary Definition Retrieved from "http://en.openei.org/w/index.php?title=Definition:Reduced_Co2_Emissions&oldid=502618

344

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

345

Solar heat collector  

Science Conference Proceedings (OSTI)

A solar heat collector is described that pre-heats water for a household hot water heating system, and also heats the air inside a house. The device includes solar heating panels set into an A-shape, and enclosing an area therein containing a water tank and a wristatic fan that utilize the heat of the enclosed air, and transmit the thermal energy therefrom through a water line and an air line into the house.

Sykes, A.B.

1981-07-28T23:59:59.000Z

346

Energy Basics: Heating Systems  

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

of energy sources, including electricity, boilers, solar energy, and wood and pellet-fuel heating. Small Space Heaters Used when the main heating system is inadequate or when...

347

Total Space Heat-  

Gasoline and Diesel Fuel Update (EIA)

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

348

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*...

349

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 (air to air heat exchanger). In my papers I use (water to air heat exchanger) as a heat recovery and I use the water as a mass recovery. The source of mass and heat recovery is the condensate water which we were dispose and connect it to the drain lines.

Hindawai, S. M.

2010-01-01T23:59:59.000Z

350

Energy Basics: Water Heating  

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

Storage Water Heaters Tankless Demand Water Heaters Heat Pump Water Heaters Solar Water Heaters Tankless Coil & Indirect Water Heaters Water Heating A variety of...

351

Total Space Heat-  

Gasoline and Diesel Fuel Update (EIA)

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

352

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...

353

Urban Heat Catastrophes  

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

The curve shows the heat index, which reflects the combined effect of temperature and humidity. Last year's Chicago heat wave created a great deal of human discomfort and,...

354

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 has good economic property, can conserve energy and protects the environment. Therefore, there is a large potential for its development. In addition, three projects using this system are presented and contrasted, which indicate that a joint system that uses both the heat pump and heat exchanger to recycle waste heat is a preferable option.

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

2006-01-01T23:59:59.000Z

355

Heat transfer assembly for a fluorescent lamp and fixture  

DOE Patents (OSTI)

In a lighting fixture including a lamp and a housing, a heat transfer structure is disclosed for reducing the minimum lamp wall temperature of a fluorescent light bulb. The heat transfer structure, constructed of thermally conductive material, extends from inside the housing to outside the housing, transferring heat energy generated from a fluorescent light bulb to outside the housing where the heat energy is dissipated to the ambient air outside the housing. Also disclosed is a method for reducing minimum lamp wall temperatures. Further disclosed is an improved lighting fixture including a lamp, a housing and the aforementioned heat transfer structure. 11 figs.

Siminovitch, M.J.; Rubenstein, F.M.; Whitman, R.E.

1992-12-29T23:59:59.000Z

356

Heat transfer assembly for a fluorescent lamp and fixture  

DOE Patents (OSTI)

In a lighting fixture including a lamp and a housing, a heat transfer structure is disclosed for reducing the minimum lamp wall temperature of a fluorescent light bulb. The heat transfer structure, constructed of thermally conductive material, extends from inside the housing to outside the housing, transferring heat energy generated from a fluorescent light bulb to outside the housing where the heat energy is dissipated to the ambient air outside the housing. Also disclosed is a method for reducing minimum lamp wall temperatures. Further disclosed is an improved lighting fixture including a lamp, a housing and the aforementioned heat transfer structure.

Siminovitch, Michael J. (Richmond, CA); Rubenstein, Francis M. (Berkeley, CA); Whitman, Richard E. (Richmond, CA)

1992-01-01T23:59:59.000Z

357

Geothermal heat pump analysis article  

U.S. Energy Information Administration (EIA)

heat pump transfers heat from the ground or ground water to provide space heating. In the summer, the heat transfer process is reversed; the ground or groundwater

358

"Nanotechnology Enabled Advanced Industrial Heat Transfer Fluids"  

DOE Green Energy (OSTI)

ABSTRACT Nanotechnology Enabled Advanced industrial Heat Transfer Fluids” Improving the efficiency of Industrial Heat Exchangers offers a great opportunity to improve overall process efficiencies in diverse industries such as pharmaceutical, materials manufacturing and food processing. The higher efficiencies can come in part from improved heat transfer during both cooling and heating of the material being processed. Additionally, there is great interest in enhancing the performance and reducing the weight of heat exchangers used in automotives in order to increase fuel efficiency. The goal of the Phase I program was to develop nanoparticle containing heat transfer fluids (e.g., antifreeze, water, silicone and hydrocarbon-based oils) that are used in transportation and in the chemical industry for heating, cooling and recovering waste heat. Much work has been done to date at investigating the potential use of nanoparticle-enhanced thermal fluids to improve heat transfer in heat exchangers. In most cases the effect in a commercial heat transfer fluid has been marginal at best. In the Phase I work, we demonstrated that the thermal conductivity, and hence heat transfer, of a fluid containing nanoparticles can be dramatically increased when subjected to an external influence. The increase in thermal conductivity was significantly larger than what is predicted by commonly used thermal models for two-phase materials. Additionally, the surface of the nanoparticles was engineered so as to have a minimal influence on the viscosity of the fluid. As a result, a nanoparticle-laden fluid was successfully developed that can lead to enhanced heat transfer in both industrial and automotive heat exchangers

Dr. Ganesh Skandan; Dr. Amit Singhal; Mr. Kenneth Eberts; Mr. Damian Sobrevilla; Prof. Jerry Shan; Stephen Tse; Toby Rossmann

2008-06-12T23:59:59.000Z

359

Reduced power consumption in  

E-Print Network (OSTI)

and a potential energy savings of over $30 Billion/year. This new approach is demanded by the exponentiallyBenefits Reduced power consumption in IC devices; hence potential energy savings of 300 Billion KWh://www.sia- online.org) CuRIE Interconnect Technology for Improved Energy Efficiency in IC Chips ARPA-E Technology

360

Reduces electric energy consumption  

E-Print Network (OSTI)

implementation of the assessment recommendations is estimated to be $843,000 with a total implementation cost. Manufacturing at the facility includes both casting and extrusion processes. Process equipment, air compressors productivity. As a result, facility production costs can be reduced and profits can be increased. August 2001

Note: This page contains sample records for the topic "reduce heat loss" 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

Ohmically heated high-density Z pinch  

SciTech Connect

The gross properties of a high-density (n approximately equal to 10$sup 27$ m$sup -3$), small-radius, (r = 10$sup -4$ m) gas-imbedded Z pinch have been examined considering only classical processes. The rate equation using only ohmic heating along with bremsstrahlung and radial heat transport shows that ohmic heating will rapidly take the pinch to thermonuclear temperatures for currents, I, greater than 1 MA. The radial heat loss for the pinch is very small for I greater than 1.5 MA. This suggests that the pinch could tolerate being driven to a nearby wall by an m = 1 kink. The laser technology for initiation of the small-diameter filament and the high-voltage technology for giving a 30-ns rise to a MA or more are available now. Some reactor considerations have been included. (auth)

Hammel, J.E.

1976-01-01T23:59:59.000Z

362

Design studies of the Moderated Thermonic Heat Pipe Reactor (MOHTR) concept  

DOE Green Energy (OSTI)

Design studies, based primarily on neutronics analysis, have been conducted on a thermionic reactor concept that uses a combined beryllium and zirconium hydride moderator to facilitate the incorporation of heat pipe cooling into compact thermionic fuel element (TFE) based designs useful in the tens of kilowatts electrical power regime. The goal of the design approach is to achieve a single point failure free system with technologies such as TFEs, high-temperature heat pipes, and ZrH moderation, which have extensive test data bases and have been shown to be capable of long lifetimes. Beryllium is used to thermally couple redundant heat pipes to TFEs and ZrH is added to reduce critical size. Neutronic analysis undertaken to investigate this design approach shows that greater reactivity can be achieved for a given geometry with a combination of the two moderator materials than with ZrH alone and that the combined moderator is much less sensitive to hydrogen loss than more traditional ZrH-moderated thermionic reactor designs. These and other analytical approaches have demonstrated the credibility of a heat pipe cooled thermionic reactor concept that has a reactor height and diameter of 60 cm and a reactor mass of 400 kg for 30-kWe power output. 14 refs., 8 figs.

Ranken, W.A.; Turner, J.A.

1991-01-01T23:59:59.000Z

363

Sound energy loss during sonolysis  

Science Conference Proceedings (OSTI)

This paper gives an analysis of sound energy losses due to sonolysis — dissociation of the part of water molecules to radicals H? and ?OH. The value of the energy loss can be evaluated by using the concentration of hydrogen peroxide which appears in the water as a result of cross?recombination of radicals ?OH+?OH=H2O2. Data previously obtained by different authors were used for the present analysis. Data for fresh water and also for water with dissolved gases were considered. Data covered a sound frequency range from 1.5 kHz to 2 MHz and sound pressure amplitudes 0.6–2.5 atm for normal static pressure and a water temperature of 20?°C. It is shown that the rate of increasing hydrogen peroxide concentration is proportional to the intensity of sound. The rate is also propor? tional to the concentration of dissolved oxygen and argon in water while other gases (hydrogen

Dmitry A. Selivanovsky; Grigory A. Domrachev

1995-01-01T23:59:59.000Z

364

Dynamic Simulation and Analysis of Heating Energy Consumption in a Residential Building  

E-Print Network (OSTI)

In winter, much of the building energy is used for heating in the north region of China. In this study, the heating energy consumption of a residential building in Tianjin during a heating period was simulated by using the EnergyPlus energy simulation program. The study showed that the heat loss from exterior walls, exterior windows and infiltration took three main parts of the total heat loss. Furthermore, the results of on-site measurement are presented with the conclusion that the EnergyPlus program provides sufficient accuracy for this energy simulation application.

Liu, J.; Yang, M.; Zhao, X.; Zhu, N.

2006-01-01T23:59:59.000Z

365

Passive magnetic bearing element with minimal power losses  

DOE Patents (OSTI)

Systems employing passive magnetic bearing elements having minimal power losses are provided. Improved stabilizing elements are shown, employing periodic magnet arrays and inductively loaded circuits, but with improved characteristics compared to the elements disclosed in U.S. Patent No. 5,495,221 entitled "Dynamically Stable Magnetic Suspension/Bearing System." The improvements relate to increasing the magnitude of the force derivative, while at the same time reducing the power dissipated during the normal operation of the bearing system, to provide a passive bearing system that has virtually no losses under equilibrium conditions, that is, when the supported system is not subject to any accelerations except those of gravity.

Post, Richard F. (Walnut Creek, CA)

1998-01-01T23:59:59.000Z

366

Transport AC loss in high temperature superconducting coils  

E-Print Network (OSTI)

, and the world’s population continues to grow, our existing methods for energy supply and usage are clearly unsustainable. In developed industrialised nations, such as the UK and the US, the industrial sector uses about one third of all energy consumed [2... superconducting coil is found to be significantly large, and this will reduce the efficiency of the device in which it is utilised, par- ticularly when the loss is reflected back to room temperature by including the refrigeration cost. Many existing AC loss...

Ainslie, Mark

2012-05-08T23:59:59.000Z

367

Loss of benefits resulting from mandated nuclear plant shutdowns  

SciTech Connect

This paper identifies and discusses some of the important consequences of nuclear power plant unavailability, and quantifies a number of technical measures of loss of benefits that result from regulatory actions such as licensing delays and mandated nuclear plant outages. The loss of benefits that accompany such regulatory actions include increased costs of systems generation, increased demand for nonnuclear and often scarce fuels, and reduced system reliability. This paper is based on a series of case studies, supplemented by sensitivity studies, on hypothetical nuclear plant shutdowns. These studies were developed by Argonne in cooperation with four electric utilities.

Peerenboom, J.P.; Buehring, W.A.

1982-01-01T23:59:59.000Z

368

Passive magnetic bearing element with minimal power losses  

DOE Patents (OSTI)

Systems employing passive magnetic bearing elements having minimal power losses are provided. Improved stabilizing elements are shown, employing periodic magnet arrays and inductively loaded circuits, but with improved characteristics compared to the elements disclosed in US Patent No. 5,495,221 entitled ``Dynamically Stable Magnetic Suspension/Bearing System.`` The improvements relate to increasing the magnitude of the force derivative, while at the same time reducing the power dissipated during the normal operation of the bearing system, to provide a passive bearing system that has virtually no losses under equilibrium conditions, that is, when the supported system is not subject to any accelerations except those of gravity. 8 figs.

Post, R.F.

1998-12-08T23:59:59.000Z

369

Optimal thermionic energy conversion with established electrodes for high-temperature topping and process heating  

DOE Green Energy (OSTI)

Advantages of thermionic energy conversion (TEC) have been counted and are recounted with emphasis on high-temperature service in coal-combustion products. Efficient, economical, nonpolluting utilization of coal here and now is a critically important national goal. And TEC can augment this capability not only by the often proposed topping of steam power plants but also by higher-temperature topping and process heating. For these applications, applied-research-and-technology (ART) work reveals that optimal TEC with approx. 1000-to approx. 1100 K collectors is possible using well-established tungsten electrodes. Such TEC with 1800 K emitters could approach 26.6% efficiency at 27.4 W/cm/sup 2/ with approx. 1000 K collectors and 21.7% at 22.6 W/cm/sup 2/ with approx. 1100 K collectors. These performances require 1.5- and 1.7-eV collector work functions (not the 1-eV ultimate) with nearly negligible interelectrode losses. Such collectors correspond to tungsten electrode systems in approx. 0.9-to approx. 6-torr cesium pressures with 1600-to-1900 K emitters. Because higher heat-rejection temperatures for TEC allow greater collector work functions, interelectrode-loss reduction becomes an increasingly important target for applications aimed at elevated temperatures. Studies of intragap modifications and new electrodes that will allow better electron emission and collection with lower cesium pressures are among the TEC-ART approaches to reduced interelectrode losses. These solutions will provide very effective TEC to serve directly in coal-combustion products for high-temperature topping and process heating. In turn this will help to use coal-and to use it well.

Morris, J.F.

1980-07-01T23:59:59.000Z

370

Liquid-fluidized-bed heat exchanger design parameters  

SciTech Connect

Liquid-fluidized-bed heat exchangers prevent scale accumulation on heat transfer surfaces and reduce the required heat transfer surface when scaling fluids, such as geothermal water, are used as the primary or working fluid. Liquid-fluidized-bed heat exchangers, principles of operation, and design parameters are described. Horizontal and vertical assemblies are discussed, including problems encountered with both designs. Bed-side heat transfer coefficients are given for limited cases, and a correlation is provided for calculating heat transfer coefficients for horizontal assemblies. A design example for a 60 kW/sub (e)/ (60 kW/sub (electric)/ preheater is included.

Allen, C.A.; Grimmett, E.S.

1978-04-01T23:59:59.000Z

371

Renewable energy technologies for federal facilities: Geothermal heat pump  

DOE Green Energy (OSTI)

This sheet summarizes information on geothermal heat pumps (GHPs), which extracts heat from the ground in the winter and transfers heat to the ground in the summer. More than 200,000 GHPs are operating in US; they can reduce energy consumption and related emissions by 23 to 44% compared to air-source heat pumps. Opportunities for use of GHPs, requirements, and cost are described. Important terms are defined.

NONE

1996-05-01T23:59:59.000Z

372

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

373

Direct fired heat exchanger  

DOE Patents (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

374

Woven heat exchanger  

DOE Patents (OSTI)

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, Roger R. (Idaho Falls, ID)

1987-01-01T23:59:59.000Z

375

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

376

METHOD FOR REDUCING THE IMPURITY RESISTIVITY OF SODIUM  

DOE Patents (OSTI)

The inherent resistivity of sodium, at cryogenic temperatures, can be reduced by clustering the impurity atoms within the crystal latiice structure of the sodium, thereby reducing the effective electron collision cross section and thus reducing the number of collisions between the electrons and such lattice imperfections. The clustering is effected by heating the sodium to a temperature approaching its melting point, and maintaining the temperature for a period of time ranging generally from two to six days. (AEC)

Post, R.F.; Taylor, C.E.

1963-08-13T23:59:59.000Z

377

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

378

Thulium-170 heat source  

SciTech Connect

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

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

1990-09-06T23:59:59.000Z

379

Reduce Climate Change  

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

Reduce Climate Change Reduce Climate Change Highway vehicles release about 1.5 billion metric tons of greenhouse gases (GHGs) into the atmosphere each year-mostly in the form of carbon dioxide (CO2)-contributing to global climate change. Each gallon of gasoline you burn creates 20 pounds of CO2. That's roughly 5 to 9 tons of CO2 each year for a typical vehicle. more... How can a gallon of gasoline create 20 pounds of carbon dioxide? It seems impossible that a gallon of gasoline, which weighs about 6.3 pounds, could produce 20 pounds of carbon dioxide (CO2) when burned. However, most of the weight of the CO2 doesn't come from the gasoline itself, but the oxygen in the air. When gasoline burns, the carbon and hydrogen separate. The hydrogen combines with oxygen to form water (H2O), and carbon combines with oxygen

380

One watt initiative: A global effort to reduce leaking electricity  

SciTech Connect

Many domestic appliances and commercial equipment consume some electric power when they are switched off or not performing their primary purpose. The typical loss per appliance is low (from 1 to 25 W) but, when multiplied by the billions of appliances in houses and in commercial buildings, standby losses represent a significant fraction of total electricity use. Several initiatives to reduce standby losses have appeared in different parts of the world. One proposal, the 1-watt plan, seeks to harmonize these initiatives by establishing a single target for all appliances. This paper explains the background to the 1-watt plan, identifies some unresolved aspects, and gives some estimates of energy savings.

Meier, Alan K.; LeBot, Benoit

1999-05-30T23:59:59.000Z

Note: This page contains sample records for the topic "reduce heat loss" 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

Reduce Threshold for Toplit Daylighting Area  

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

Supporting analysis for proposed Supporting analysis for proposed changes to the commercial provisions of the 2012 IECC: Reduce Threshold for Toplit Daylighting Area R Hart R Athalye Pacific Northwest National Laboratory December 2012 2 Proposal Description This proposal modifies Section C402.3.2 of the 2012 IECC for the 2015 version. It reduces the area threshold for skylight daylit zones from 10,000 square feet to 2,000 square feet. It maintains 15 foot ceiling height requirement and the exception for climate zones 6 through 8. Energy Impact Based on average national energy prices 1 of $0.99 per therm and $0.1032 per kWh, the net savings are calculated with EnergyPlus(tm) 2 from whole building energy savings that result from reduced lighting, and depending on climate zone, increased or decreased heating and cooling.

382

Reversible and irreversible processes in dispersive/dissipative optical media: Electro-magnetic free energy and heat production  

E-Print Network (OSTI)

We solve the problem addressed by Landau and Lifshitz in 1958, and Oughstun and Sherman of determining the dynamical losses in a purely dissipative dielectric media. We develop concrete notions of macroscopic free energy and losses as energy which is reversible and irreversible, respectively, in the medium-field interaction. We define the reversible and irreversible energies and outline the derivation of said quantities. We examine the implications of our definition and it's auxiliary quantity, the reversal field, for the single Lorentz oscillator model of a medium. We show that for this model the reversible energy reduces to the sum of the kinetic and potential energy, as found by Loudon. We note that in general, the sum of the kinetic and potential energies is greater than the reversible energy. We show that the reversible and irreversible energy have the characteristics classically defining free energy and heat.

C. Broadbent; G. Hovhannisyan; M. Clayton; J. Peatross; S. A. Glasgow

2002-07-31T23:59:59.000Z

383

Naval electrochemical corrosion reducer  

DOE Patents (OSTI)

A corrosion reducer for use with ships having a hull, a propeller mounted a propeller shaft and extending through the hull, bearings supporting the shaft, at least one thrust bearing and one seal. The improvement includes a current collector and a current reduction assembly for reducing the voltage between the hull and shaft in order to reduce corrosion due to electrolytic action. The current reduction assembly includes an electrical contact, the current collector, and the hull. The current reduction assembly further includes a device for sensing and measuring the voltage between the hull and the shaft and a device for applying a reverse voltage between the hull and the shaft so that the resulting voltage differential is from 0 to 0.05 volts. The current reduction assembly further includes a differential amplifier having a voltage differential between the hull and the shaft. The current reduction assembly further includes an amplifier and a power output circuit receiving signals from the differential amplifier and being supplied by at least one current supply. The current selector includes a brush assembly in contact with a slip ring over the shaft so that its potential may be applied to the differential amplifier.

Clark, Howard L. (Ballston Lake, NY)

1991-10-01T23:59:59.000Z

384

Experimental Investigation on Thermal Properties of a Steel-jacketed Steam Heating Pipeline with Vacuum Insulation  

E-Print Network (OSTI)

The steel-jacketed steam heating pipeline employs vacuum insulation to improve the insulating effect and reduce the corrosion, and hence increases the heat transfer efficiency of the heating network and building energy efficiency. It is important in improving the thermal insulation to investigate the impact of factors that insulate the effects and thermal properties of the pipeline. The thermal insulation of this pipeline comprises the vacuum layer and the insulating material layer. Experiments were performed to measure the combined heat transfer and equivalent thermal conductivities of the insulating material in the vacuum and rarefied air employed in the pipeline's insulation. The thermal properties of this type of insulation at vacuum pressures of 0.5~1013mbar, employing thermal media temperatures of 343~573K and with different thicknesses of vacuum layer, are discussed for this pipeline, for which diameters of inner steel pipe/steel jacket are DN50/DN250, DN100/DN300, DN200/DN500 and DN500/DN850, respectively. The results show that reduction in vacuum pressure reduces the heat loss in the pipeline. The equivalent thermal conductivity of the insulating material layer is distinctively lower than the vacuum layer, but decreasing the vacuum pressure improves the insulating effect of vacuum layer substantially more than insulating the material layer. As the vacuum pressure decreases from 1013mbar (atmospheric pressure) to 10mbar at the thermal media temperature of 523K e.g., the reduction of equivalent thermal conductivities of vacuum layer is approximately three times greater than that of insulating material layer. The equivalent thermal conductivities of the vacuum layer are lower and decease faster as the vacuum pressure is lower than 100mbar, but the equivalent thermal conductivities of insulating material layer are lower and decease faster as the vacuum pressure is lower than 50mbar. The pressure in vacuum insulation should be controlled lower than 20mbar to achieve desirable insulating effects. Every 10mm addition of thickness of insulating material layer (every 10mm reduction of thickness of vacuum layer) decreases the heat loss of approximately 6.8 percent at the vacuum pressure of 0.5mbar.

Na, W.; Zou, P.

2006-01-01T23:59:59.000Z

385

Measurement of the solar heat gain coefficient and U value of windows with insect screens  

SciTech Connect

Energy ratings are currently being used in a number of countries to assist in the selection of windows and doors based on energy performance. Developed for simple comparison purposes, these rating numbers do not take into account window removable attachments such as insect screens that are, nevertheless, widely used. Research was carried out to assess the effect of insect screens on the heat gains and losses of windows. The work reported in this paper deals with the effect of one screen type on the performance of a base-case, double-glazed window. Using an indoor solar simulator facility, measurements of the window solar heat gain coefficient (SHGC) and U value were made for different screen attachment configurations and climatic conditions. Results with the sample window tested indicate that insect screens placed on the outdoor side can reduce its SHGC by 46% with only a 7% reduction in its U value (0.19 W/m{sup 2}{center_dot}C), and that insect screens placed on the indoor side can reduce its SHGC by 15% while reducing its U value by 14% (0.38 W/m{sup 2}{center_dot}C).

Brunger, A.; Dubrous, F.M.; Harrison, S.

1999-07-01T23:59:59.000Z

386

Energy 101: Geothermal Heat Pumps | Department of Energy  

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

Energy 101: Geothermal Heat Pumps Energy 101: Geothermal Heat Pumps Energy 101: Geothermal Heat Pumps January 4, 2011 - 12:15pm Addthis An energy-efficient heating and cooling alternative, the geothermal heat pump system moves heat from the ground to a building (or from a building to the ground) through a series of flexible pipe "loops" containing water. This edition of Energy 101 explores the benefits Geothermal and the science behind how it all comes together. John Schueler John Schueler Former New Media Specialist, Office of Public Affairs Quick Facts Heat pump systems can lower energy bills by up to 70% over traditional types of heating systems. During this time of year, many homeowners are searching for ways to reduce steep heating costs. One of the options they should consider during the

387

Energy 101: Geothermal Heat Pumps | Department of Energy  

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

Energy 101: Geothermal Heat Pumps Energy 101: Geothermal Heat Pumps Energy 101: Geothermal Heat Pumps January 4, 2011 - 12:15pm Addthis An energy-efficient heating and cooling alternative, the geothermal heat pump system moves heat from the ground to a building (or from a building to the ground) through a series of flexible pipe "loops" containing water. This edition of Energy 101 explores the benefits Geothermal and the science behind how it all comes together. John Schueler John Schueler Former New Media Specialist, Office of Public Affairs Quick Facts Heat pump systems can lower energy bills by up to 70% over traditional types of heating systems. During this time of year, many homeowners are searching for ways to reduce steep heating costs. One of the options they should consider during the

388

Energy Basics: Absorption Heat Pumps  

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

but by a heat source such as natural gas, propane, solar-heated water, or geothermal-heated water. Because natural gas is the most common heat source for absorption heat...

389

Ground Loops for Heat Pumps and Refrigeration  

E-Print Network (OSTI)

Ground loops are used for water source heat pumps. Refrigeration can be put on a ground loop. Water-cooled condensing units are more efficient than air-cooled, and they can be put indoors. Indoor location makes piping for desuperheater hot water easy. Since refrigeration equipment runs more than heat pumps, energy savings can be large for ground-coupled refrigeration. The paper presents a design procedure for ground loops for heat pumps, hot water, ice machines, and water-cooled refrigeration. It gives an overview of the commercial ground-coupled systems in Louisiana that have both refrigeration and heat pumps. Systems vary from small offices to a three-story office building with 187 tons. A chain of hamburger outlets uses total ground-coupling in all of its stores. A grocery store has ground-coupling for heat pumps and refrigeration. Desuperheaters provide 80 percent of the hot water for a coin laundry in the same building. A comparison of energy costs in a bank with a ground-coupled heat pump system to a similar bank with air-conditioning and gas for heat revealed a 31 percent reduction in utility costs for the ground-coupled building. Two buildings of the Mississippi Power and Light Co. have ground-coupled heat pumps in one, and high efficiency air source heat pumps in the other. Energy savings in nine months was 60,000 kWh (25 percent), and electric peak demand was reduced 42 kW (35 percent).

Braud, H. J.

1986-01-01T23:59:59.000Z

390

Design and Experiments of a Solar Low-temperature Hot Water Floor Radiant Heating System  

E-Print Network (OSTI)

The solar low-temperature hot water floor radiant heating system combines solar energy heating with floor radiant heating. This kind of environmental heating way not only saves fossil resources and reduces pollution, but also makes people feel more comfortable. First, the authors devised an experimental scheme and set up the laboratory. Second, we collected a great deal of data on the system in different situations. Finally, we conclude that such heating system is feasible and one of the best heating methods.

Wu, Z.; Li, D.

2006-01-01T23:59:59.000Z

391

Mechanical model for ductility loss  

Science Conference Proceedings (OSTI)

A mechanical model was constructed to probe into the mechanism of ductility loss. Fracture criterion based on critical localized deformation was undertaken. Two microstructure variables were considered in the model. Namely, the strength ratio of grain boundary affected area to the matrix, ..cap omega.., and the linear fraction, x, of grain boundary affected area. A parametrical study was carried out. The study shows that the ductility is very sensitive to those microstructure parameters. The functional dependence of ductility to temperature as well as strain-rate, suggested by the model, is demonstrated to be consistent with the observation.

Hu, W.L.

1980-02-11T23:59:59.000Z

392

High Temperature Variable Conductance Heat Pipes for Radioisotope Stirling Systems  

SciTech Connect

In a Stirling radioisotope system, heat must continually be removed from the GPHS modules, to maintain the GPHS modules and surrounding insulation at acceptable temperatures. Normally, the Stirling converter provides this cooling. If the Stirling engine stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS, but also ending the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) is under development to allow multiple stops and restarts of the Stirling engine. The status of the ongoing effort in developing this technology is presented in this paper. An earlier, preliminary design had a radiator outside the Advanced Stirling Radioisotope Generator (ASRG) casing, used NaK as the working fluid, and had the reservoir located on the cold side adapter flange. The revised design has an internal radiator inside the casing, with the reservoir embedded inside the insulation. A large set of advantages are offered by this new design. In addition to reducing the overall size and mass of the VCHP, simplicity, compactness and easiness in assembling the VCHP with the ASRG are significantly enhanced. Also, the permanently elevated temperatures of the entire VCHP allows the change of the working fluid from a binary compound (NaK) to single compound (Na). The latter, by its properties, allows higher performance and further mass reduction of the system. Preliminary design and analysis shows an acceptable peak temperature of the ASRG case of 140 deg. C while the heat losses caused by the addition of the VCHP are 1.8 W.

Tarau, Calin; Walker, Kara L.; Anderson, William G. [Advanced Cooling Technologies, Inc. 1046 New Holland Ave. Lancaster, PA 17601 (United States)

2009-03-16T23:59:59.000Z

393

Analysis of heat-pipe absorbers in evacuated-tube solar collectors  

SciTech Connect

Heat transfer in evacuated-tube solar collectors with heat-pipe absorbers is compared with that for similar collectors with flow-through absorbers. In systems that produce hot water or other heated fluids, the heat-pipe absorber suffers a heat transfer penalty compared with the flow-through absorber, but in many cases the penalty can be minimized by proper design at the heat-pipe condenser and system manifold. The heat transfer penalty decreases with decreasing collector heat loss coefficient, suggesting that evacuated tubes with optical concentration are more appropriate for use with heat pipes than evacuated or nonevacuated flat-plate collectors. When the solar collector is used to drive an absorption chiller, the heat-pipe absorber has better heat transfer characteristics than the flow-through absorbers.

Hull, J.R.; Schertz, W.W.; Allen, J.W.

1986-02-01T23:59:59.000Z

394

Latent heat accumulating greenhouse  

Science Conference Proceedings (OSTI)

This invention relates to a latent heat accumulating greenhouse utilizing solar heat. The object of the invention is to provide a greenhouse which is simple in construction, of high efficiency for heat absorbing and capable of much absorbing and accumulating of heat. A heat accumulating chamber partitioned by transparent sheets is provided between the attic and a floor surface facing north in the greenhouse. A blower fan is disposed to confront an opening provided at the lower portion in said heat accumulating chamber. Also, in the heat accumulating chamber, a heat accumulating unit having a large number of light transmitting windows and enclosing a phase transformation heat accumulating material such as CaC1/sub 2/.6H/sub 2/O, Na/sub 2/SO/sub 4/.10H/sub 2/O therein is detachably suspended in a position close to windowpanes at the north side.

Yano, N.; Ito, H.; Makido, I.

1985-04-16T23:59:59.000Z

395

Energy Basics: Air-Source Heat Pumps  

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

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

396

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

SciTech Connect

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

Mittereder, N.; Poerschke, A.

2013-11-01T23:59:59.000Z

397

Heat-driven acoustic cooling engine having no moving parts  

DOE Patents (OSTI)

A heat-driven acoustic cooling engine having no moving parts receives heat from a heat source. The acoustic cooling engine comprises an elongated resonant pressure vessel having first and second ends. A compressible fluid having a substantial thermal expansion coefficient and capable of supporting an acoustic standing wave is contained in the resonant pressure vessel. The heat source supplies heat to the first end of the vessel. A first heat exchanger in the vessel is spaced-apart from the first end and receives heat from the first end. A first thermodynamic element is adjacent to the first heat exchanger and converts some of the heat transmitted by the first heat exchanger into acoustic power. A second thermodynamic element has a first end located spaced-apart from the first thermodynamic element and a second end farther away from the first thermodynamic element than is its first end. The first end of the second thermodynamic element heats while its second end cools as a consequence of the acoustic power. A second heat exchanger is adjacent to and between the first and second thermodynamic elements. A heat sink outside of the vessel is thermally coupled to and receives heat from the second heat exchanger. The resonant pressure vessel can include a housing less than one-fourth wavelength in length coupled to a reservoir. The housing can include a reduced diameter portion communicating with the reservoir.

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

1989-01-01T23:59:59.000Z

398

Heat flow in relation to hydrothermal activity in the southern Black Rock Desert, Nevada  

DOE Green Energy (OSTI)

As part of an investigation of the Gerlach NE KGRA (Known Geothermal Resource Area) a number of heat-flow measurements were made in playa sediments of the southern Black Rock Desert, northwestern Nevada. These data together with additional previously unpublished heat-flow values reveal a complex pattern of heat flow with values ranging between 1.0 to 5.0 HFU (40 to 100 mWm/sup -2/) outside of the hot springs area. The mean heat flow for the 13 reported sites in the southern Black Rock Desert is 1.8 +- 0.15 HFU (75 +- 6 mWm/sup -2/). The complexity of the pattern of heat flow is believed to arise from hydrothermal circulation supporting the numerous hot springs throughout the region. The fact that the lowest observed heat flow occurs in the deepest part of the basin strongly suggests that fluid movement within the basin represents part of the recharge for the hydrothermal system. A thermal balance for the system incorporating both anomalous conductive heat loss and convective heat loss from the spring systems indicate a total energy loss of about 8.0 Mcal/sec or 34 megawatts over an estimated 1000 km/sup 2/ region. Consideration of this additional heat loss yields a mean regional heat flow of 2.5 + HFU (100 + mWm/sup -2/) and warrants inclusion of this region in the Battle Mountain heat-flow high (Lachenbruch and Sass, 1977, 1978).

Sass, J.H.; Zoback, M.L.; Galanis, S.P. Jr.

1979-01-01T23:59:59.000Z

399

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

400

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

Note: This page contains sample records for the topic "reduce heat loss" 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

Laundry heat recovery system  

SciTech Connect

A laundry heat recovery system includes a heat exchanger associated with each dryer in the system, the heat exchanger being positioned within the exhaust system of the dryer. A controller responsive to the water temperature of the heat exchangers and the water storage for the washer selectively circulates the water through a closed loop system whereby the water within the exchangers is preheated by the associated dryers. By venting the exhaust air through the heat exchanger, the air is dehumidified to permit recirculation of the heated air into the dryer.

Alio, P.

1985-04-09T23:59:59.000Z

402

Wound tube heat exchanger  

DOE Patents (OSTI)

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

Ecker, Amir L. (Duncanville, TX)

1983-01-01T23:59:59.000Z

403

Heat Recovery Steam Generator (HRSG) Deposits  

Science Conference Proceedings (OSTI)

Under-deposit corrosion represents the second leading mechanism of chemistry-influenced heat recovery steam generator (HRSG) tube failures (HTFs) and third leading cause of major availability losses. This report was prepared, in recognition of the lack of information, to assemble the state of knowledge on deposition in HRSG high-pressure (HP) evaporator tubing and to identify the major deficiencies in that knowledge. Findings of this effort can be used to establish immediate remediation and correction of...

2009-11-11T23:59:59.000Z

404

Clean Firetube Boiler Waterside Heat Transfer Surfaces, Energy Tips: STEAM, Steam Tip Sheet #7 (Fact Sheet)  

SciTech Connect

A steam energy tip sheet for the Advanced Manufacturing Office (AMO). The prevention of scale formation in firetube boilers can result in substantial energy savings. Scale deposits occur when calcium, magnesium, and silica, commonly found in most water supplies, react to form a continuous layer of material on the waterside of the boiler heat exchange tubes. Scale creates a problem because it typically possesses a thermal conductivity, an order of magnitude less than the corresponding value for bare steel. Even thin layers of scale serve as an effective insulator and retard heat transfer. The result is overheating of boiler tube metal, tube failures, and loss of energy efficiency. Fuel consumption may increase by up to 5% in firetube boilers because of scale. The boilers steam production may be reduced if the firing rate cannot be increased to compensate for the decrease in combustion efficiency. Energy losses as a function of scale thickness and composition are given. Any scale in a boiler is undesirable. The best way to deal with scale is not to let it form in the first place. Prevent scale formation by: (1) Pretreating of boiler makeup water (using water softeners, demineralizers, and reverse osmosis to remove scale-forming minerals); (2) Injecting chemicals into the boiler feedwater; and (3) Adopting proper boiler blowdown practices.

Not Available

2012-04-01T23:59:59.000Z

405

Heat Exchangers for Solar Water Heating Systems | Department of Energy  

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

Heat Exchangers for Solar Water Heating Systems Heat Exchangers for Solar Water Heating Systems Heat Exchangers for Solar Water Heating Systems May 30, 2012 - 3:40pm Addthis Image of a heat exchanger. | Photo from iStockphoto.com Image of a heat exchanger. | Photo from iStockphoto.com Solar water heating systems use heat exchangers to transfer solar energy absorbed in solar collectors to the liquid or air used to heat water or a space. Heat exchangers can be made of steel, copper, bronze, stainless steel, aluminum, or cast iron. Solar heating systems usually use copper, because it is a good thermal conductor and has greater resistance to corrosion. Types of Heat Exchangers Solar water heating systems use three types of heat exchangers: Liquid-to-liquid A liquid-to-liquid heat exchanger uses a heat-transfer fluid that

406

Reduced Thermal Conductivity of Compacted Silicon Nanowires  

E-Print Network (OSTI)

Chen, “Coherent Phonon Heat Conduction in Superlattices,”1 Chapter 1: Heat Conduction in Nanostructured Materialsfindings. Chapter 1: Heat Conduction in Nanostructured

Yuen, Taylor S.

407

Soft Switching Approach to Reducing Transition Losses in an On/Off  

E-Print Network (OSTI)

pressure throttling of hydraulic oil through metering or relief valves. An example of an on/ off controlled system is the virtual variable displacement pump pro- posed by Tomlinson and Burrows [1] and studied by Li et al. [2], shown in Fig. 1. In this circuit, the on/off valve sends the full pump flow to either

Li, Perry Y.

408

REDUCING MISMATCH LOSSES IN GRID-CONNECTED RESIDENTIAL BIPV ARRAYS USING ACTIVE POWER CONVERSION COMPONENTS  

E-Print Network (OSTI)

/Simulink© environment for each topology using a 3 kWp rooftop-type plant. Simulation results show that a considerable amount of additional solar generated energy can be grid-fed using alternative plant layouts. 1 occur due to nearby buildings, trees, antennas or chimneys, which are usually inherent to the solar

Paris-Sud XI, Université de

409

Unvented Attic Increases Energy Efficiency and Reduces Duct Losses - Sun Lake at Banning, California  

SciTech Connect

New houses in the Sun Lakes at Banning subdivision are designed by Pulte Homes with technical support from the Building Science Consortium as part of the U.S. Department of Energy's Building America Program. These homes save their homeowners money by applying the principles of ''whole-building'' design, which considers the house as a complete system instead of separate components.

Anderson, R.; Wells, N.

2001-09-05T23:59:59.000Z

410

Energy Efficient Process Heating: Insulation and Thermal Mass Kevin Carpenter and Kelly Kissock  

E-Print Network (OSTI)

1 Energy Efficient Process Heating: Insulation and Thermal Mass Kevin Carpenter and Kelly Kissock tanks and reducing thermal mass. A companion paper, Energy Efficiency Process Heating: Managing Air Flow of the oven/furnace. Reducing the quantity of energy lost to thermal mass in a process heating system saves

Kissock, Kelly

411

Energy-Efficiency Options for Insurance Loss Prevention  

SciTech Connect

Energy-efficiency improvements offer the insurance industry two areas of opportunity: reducing ordinary claims and avoiding greenhouse gas emissions that could precipitate natural disaster losses resulting from global climate change. We present three vehicles for taking advantage of this opportunity, including research and development, in- house energy management, and provision of key information to insurance customers and risk managers. The complementary role for renewable energy systems is also introduced.

Mills, E. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States). Environmental Energy Technologies Div.; Knoepfel, I. [Swiss Reinsurance Co., Zurich (Switzerland)

1997-06-09T23:59:59.000Z

412

Loss mechanisms in turbine tip clearance flows  

E-Print Network (OSTI)

Numerical simulations of tip clearance ow have been carried out to dene the loss generation mechanisms associated with tip leakage in unshrouded axial turbines. Mix- ing loss between the leakage, which takes the form of a ...

Huang, Arthur (Arthur C.)

2011-01-01T23:59:59.000Z

413

Horizontal Heat Exchanger Design and Analysis for Passive Heat Removal Systems  

Science Conference Proceedings (OSTI)

This report describes a three-year project to investigate the major factors of horizontal heat exchanger performance in passive containment heat removal from a light water reactor following a design basis accident LOCA (Loss of Coolant Accident). The heat exchanger studied in this work may be used in advanced and innovative reactors, in which passive heat removal systems are adopted to improve safety and reliability The application of horizontal tube-bundle condensers to passive containment heat removal is new. In order to show the feasibility of horizontal heat exchangers for passive containment cooling, the following aspects were investigated: 1. the condensation heat transfer characteristics when the incoming fluid contains noncondensable gases 2. the effectiveness of condensate draining in the horizontal orientation 3. the conditions that may lead to unstable condenser operation or highly degraded performance 4. multi-tube behavior with the associated secondary-side effects This project consisted of two experimental investigations and analytical model development for incorporation into industry safety codes such as TRAC and RELAP. A physical understanding of the flow and heat transfer phenomena was obtained and reflected in the analysis models. Two gradute students (one funded by the program) and seven undergraduate students obtained research experience as a part of this program.

Vierow, Karen

2005-08-29T23:59:59.000Z

414

Ion Bernstein wave heating research  

SciTech Connect

Ion Bernstein wave heating (IBWH) utilizes the ion Bernstein wave (IBW), a hot plasma wave, to carry the radio frequency (rf) power to heat tokamak reactor core. Earlier wave accessibility studies have shown that this finite-Larmor-radius (FLR) mode should penetrate into a hot dense reactor plasma core without significant attenuation. Moreover, the IBW`s low phase velocity ({omega}/k{sub {perpendicular}} {approx} V{sub Ti} {much_lt} V{sub {alpha}}) greatly reduces the otherwise serious wave absorption by the 3.5 MeV fusion {alpha}-particles. In addition, the property of IBW`s that k{sub {perpendicular}} {rho}{sub i} {approx} 1 makes localized bulk ion heating possible at the ion cyclotron harmonic layers. Such bulk ion heating can prove useful in optimizing fusion reactivity. In another vein, with proper selection of parameters, IBW`s can be made subject to strong localized electron Landau damping near the major ion cyclotron harmonic resonance layers. This property can be useful, for example, for rf current drive in the reactor plasma core. This paper discusses this research.

Ono, Masayuki

1992-03-01T23:59:59.000Z

415

Ion Bernstein wave heating research  

Science Conference Proceedings (OSTI)

Ion Bernstein wave heating (IBWH) utilizes the ion Bernstein wave (IBW), a hot plasma wave, to carry the radio frequency (rf) power to heat tokamak reactor core. Earlier wave accessibility studies have shown that this finite-Larmor-radius (FLR) mode should penetrate into a hot dense reactor plasma core without significant attenuation. Moreover, the IBW's low phase velocity ({omega}/k{sub {perpendicular}} {approx} V{sub Ti} {much lt} V{sub {alpha}}) greatly reduces the otherwise serious wave absorption by the 3.5 MeV fusion {alpha}-particles. In addition, the property of IBW's that k{sub {perpendicular}} {rho}{sub i} {approx} 1 makes localized bulk ion heating possible at the ion cyclotron harmonic layers. Such bulk ion heating can prove useful in optimizing fusion reactivity. In another vein, with proper selection of parameters, IBW's can be made subject to strong localized electron Landau damping near the major ion cyclotron harmonic resonance layers. This property can be useful, for example, for rf current drive in the reactor plasma core. This paper discusses this research.

Ono, Masayuki.

1992-03-01T23:59:59.000Z

416

Pressure reducing regulator  

DOE Patents (OSTI)

A pressure reducing regulator that controls its downstream or outlet pressure to a fixed fraction of its upstream or inlet pressure is disclosed. The regulator includes a housing which may be of a titanium alloy, within which is located a seal or gasket at the outlet end which may be made of annealed copper, a rod, and piston, each of which may be made of high density graphite. The regulator is insensitive to temperature by virtue of being without a spring or gas sealed behind a diaphragm, and provides a reference for a system in which it is being used. The rod and piston of the regulator are constructed, for example, to have a 1/20 ratio such that when the downstream pressure is less than 1/20 of the upstream pressure the regulator opens and when the downstream pressure exceeds 1/20 of the upstream pressure the regulator closes. 10 figs.

Whitehead, J.C.; Dilgard, L.W.

1995-10-10T23:59:59.000Z

417

Reducing Leaking Electricity  

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

4 4 Reducing Leaking Electricity Figure 1. Full and standby power draws of some compact audio systems. A surprisingly large number of appliances-from computer peripherals to cable TV boxes to radios-consume electricity even after they have been switched off. Other appliances, such as cordless telephones, remote garage door openers, and battery chargers don't get switched off but draw power even when they are not performing their principal functions. The energy used while the appliance is switched off or not performing its primary purpose is called "standby consumption" or "leaking electricity." This consumption allows TVs, VCRs and garage-door openers to be ready for instant-on with a remote control, microwave ovens to display a digital

418

No loss fueling station for liquid natural gas vehicles  

SciTech Connect

This patent describes a no loss fueling station for delivery of liquid natural gas (LNG) to a use device such as a motor vehicle. It comprises: a pressure building tank holding a quantity of LNG and gas head; means for delivering LNG to the pressure building tank; means for selectively building the pressure in the pressure building tank; means for selectively reducing the pressure in the pressure building tank; means for controlling the pressure building and pressure reducing means to maintain a desired pressure in the pressure building tank without venting natural gas to the atmosphere; and means for delivering the LNG from the pressure building tank to the use device.

Cieslukowski, R.E.

1992-06-16T23:59:59.000Z

419

Performance of a solar energy-assisted heat pump heating system: analysis and correlation of field-collected data  

SciTech Connect

An analysis of building energy usage and thermal load for the Solar Building during the winter heating seasons of 1974-75 and 1975-76 is reported. The one-story office building is located in Albuquerque, New Mexico. Its mechanical heating and cooling equipment is categorized as a solar-assisted heat pump system consisting of solar collectors, water thermal storage, a water-to-water heat pump and five smaller water-to-air heat pump packaged units. Building energy usage was examined with emphasis on the time of day energy was consumed and the source from which the energy was obtained; i.e., from the electricity for lighting, office equipment and mechanical equipment, and from the heat output of the thermal storage and heat pumps. The rate of electrical energy consumption was found to be very dependent on building use. High rates of electrical energy usage during occupied periods required cooling during parts of even the coldest days. Mechanical equipment heating was found to vary as a function of building usage as well as a function of the indoor-outdoor temperature differential. Energies supplied to and withdrawn from the building were examined and are presented for hourly, daily, and seasonal periods. A comparison of the two heating seasons was made. Energy losses and gains from the building to the surroundings were examined for both steady-state and transient load profiles. Envelope conductive heat losses and losses due to infiltration and ventilation were calculated using actual weather data through the use of the Building Environmental Analysis Program (BEAP). The effect of building thermal storage on heating and cooling loads was examined and a set of building balance-point temperatures was established. Comparisons between the building energy consumption and a calculated load were made for hourly, daily, and seasonal periods.

Williams, R.C.

1979-08-01T23:59:59.000Z

420

Louisiana Wetland Loss Fact at Askives  

U.S. Energy Information Administration (EIA)

Louisiana Wetland Loss Fact? - Find Questions and Answers at Askives, the first startup that gives you an straight answer

Note: This page contains sample records for the topic "reduce heat loss" 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

A model for calculation of RCS pressure during reflux boiling under reduced inventory conditions and its assessment against PKL data  

SciTech Connect

There has been recent interest in the United States concerning the loss of residual heat removal system (RHRS) under reduced coolant inventory conditions for pressurized water reactors. This issue is also of interest in the Federal Republic of Germany and an experiment was performed in the integral PKL-HI experimental facility at Siemens-KWU to supply applicable data. Recently, an NRC-sponsored effort has been undertaken at the Idaho-National Engineering Laboratory to identify and analyze the important thermal-hydraulic phenomena in pressurized water reactors following the long term loss-of-RHRS during reduced inventory operation. The thermal-hydraulic response of a closed reactor coolant system during such a transient is investigated in this report. Some of the specific processes investigated include: reflux condensation in the steam generators, the corresponding pressure increase in the reactor coolant system, and void fraction distributions on the primary side of the system. Mathematical models of these and other physical processes Experiment B4.5.

Palmrose, D.E. [EG and G Idaho, Inc., Idaho Falls, ID (United States); Mandl, R.M. [Siemens AG, Berlin (Germany)

1991-12-31T23:59:59.000Z

422

Rapid plasma heating by collective interactions, using strong turbulence and relativistic electron beams  

SciTech Connect

A multi-kilovolt, moderate density plasma was generated in a magnetic mirror confinement system by two methods: turbulent heating and relativistic electron beam. Extensive diagnostic development permitted the measurement of important plasma characteristics, leading to interesting and novel conclusions regarding heating and loss mechanisms. Electron and ion heating mechanisms were categorized, and parameter studies made to establish ranges of importance. Nonthermal ion and electron energy distributions were measured. Beam propagation and energy deposition studies yielded the spatial dependence of plasma heating.

Wharton, C.B.

1977-01-01T23:59:59.000Z

423

Section D: SPACE HEATING  

U.S. Energy Information Administration (EIA)

Central warm-air furnace with ducts to individual rooms other than a heat pump ..... 03 Steam/Hot water ... REVERSE Heat pump ... Don't have a separate water heater ...

424

Electric Resistance Heating  

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

Electric resistance heat can be supplied by centralized forced-air electric furnaces or by heaters in each room. Electric resistance heating converts nearly all of the energy in the electricity to...

425

Space Heating and Cooling  

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

A wide variety of technologies are available for heating and cooling homes and other buildings. In addition, many heating and cooling systems have certain supporting equipment in common, such as...

426

Heat pipe fabrication  

SciTech Connect

A heat pipe is disclosed which is fabricated with an artery arranged so that the warp and weave of the wire mesh are at about a 45/sup 0/ angle with respect to the axis of the heat pipe.

Leinoff, S.; Edelstein, F.; Combs, W.

1977-01-18T23:59:59.000Z

427

Total Space Heat-  

Gasoline and Diesel Fuel Update (EIA)

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

428

HEAT TRANSFER IN UNDERGROUND HEATING EXPERIMENTS IN GRANITE, STRIPA, SWEDEN  

E-Print Network (OSTI)

Analysis of. Nonlinear Heat Transfer Problems." Report no.Berkeley, Ca. , APPENDIX A. HEAT TRANSFER BY CONDUCTION ANDMeeting, Technical Session on Heat Transfer in Nuclear Waste

Chan, T.

2010-01-01T23:59:59.000Z

429

Consolidated Electric Cooperative- Heat Pump and Water Heating Rebates  

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

430

HEAT TRANSFER IN UNDERGROUND HEATING EXPERIMENTS IN GRANITE, STRIPA, SWEDEN  

E-Print Network (OSTI)

CLOSED-FORM INTEGRAL SOLUTIONS FOR LINEAR HEAT CONDUCTION.For linear heat conduction in a homogeneous, isotropiclaw of similitude for linear heat conduction was utilized to

Chan, T.

2010-01-01T23:59:59.000Z

431

Conditions for making direct reduced iron, transition direct reduced iron and pig iron nuggets in a laboratory furnace - Temperature-time transformations  

Science Conference Proceedings (OSTI)

The pig iron nugget process is gaining in importance as an alternative to the traditional blast furnace. Throughout the process, self-reducing-fluxing dried greenballs composed of iron ore concentrate, reducing-carburizing agent (coal), flux (limestone) and binder (bentonite) are heat-treated. During the heat treatment, dried greenballs are first transformed into direct reduced iron (DRI), then to transition direct reduced iron (TDRI) and finally to pig iron nuggets. The furnace temperature and/or residence time and the corresponding levels of carburization, reduction and metallization dictate these transformations. This study involved the determination of threshold furnace temperatures and residence times for completion of all of the transformation reactions and pig iron nugget production. The experiments involved the heat treatment of self-reducing-fluxing dried greenballs at various furnace temperatures and residence times. The products of these heat treatments were identified by utilizing optical microscopy, apparent density and microhardness measurements.

Anameric, B.; Kawatra, S.K. [Michigan Technological University, Houghton, MI (United States). Dept. of Chemical Engineering

2007-02-15T23:59:59.000Z

432

Solar heat receiver  

DOE Patents (OSTI)

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

Hunt, Arlon J. (Oakland, CA); Hansen, Leif J. (Berkeley, CA); Evans, David B. (Orinda, CA)

1985-01-01T23:59:59.000Z

433

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

434

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

435

Flue heat reclaimer  

Science Conference Proceedings (OSTI)

A flue heat reclaimer is constructed to be mounted on the exterior of a flue duct of a heater and provide a spiral-shaped heat transfer passage extending around the flue duct. A fan causes air to flow through the heat transfer passage so that the temperature of this air is elevated by reason at its extended heat transfer relationship with the flue duct.

Paolino, R.J.

1983-05-03T23:59:59.000Z

436

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

437

Method and apparatus for reducing mixed waste  

DOE Patents (OSTI)

The present invention is a method and apparatus for in-can waste reduction. The method is mixing waste with combustible material prior to placing the waste into a waste reduction vessel. The combustible portion is ignited, thereby reducing combustible material to ash and non-combustible material to a slag. Further combustion or heating may be used to sinter or melt the ash. The apparatus is a waste reduction vessel having receiving canister connection means on a first end, and a waste/combustible mixture inlet on a second end. An oxygen supply is provided to support combustion of the combustible mixture.

Elliott, Michael L. (Kennewick, WA); Perez, Jr., Joseph M. (Richland, WA); Chapman, Chris C. (Richland, WA); Peters, Richard D. (Pasco, WA)

1995-01-01T23:59:59.000Z

438

HEAT TRANSFER MEANS  

DOE Patents (OSTI)

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

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

1961-07-11T23:59:59.000Z

439

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

440

Heat Integration and Heat Recovery at a Large Chemical Manufacturing Plant  

E-Print Network (OSTI)

The Honeywell chemical plant located in Hopewell, Virginia includes processing units that purify raw phenol, react the phenol with hydrogen to form crude cyclohexanone, and purify the crude cyclohexanone. In order to reduce energy usage, two opportunities for heat recovery and heat integration were identified. A feasibility study and economic analysis were performed on the two opportunities, and both projects were implemented. The first project utilized the heat contained in a distillation process overheads stream to preheat the raw material entering the distillation process. This was accomplished via a heat exchanger, and reduced the utility steam requirement by 10,000 pph. The second project utilized the heat generated by the hydrogenation reaction (in the form of waste heat steam) to preheat the feed material in an adjacent process. This was accomplished via a heat exchanger, and reduced the utility steam requirement by 8,000 pph. These two energy projects required $1.1 million of capital and saved $1.0 million in utility steam annually.

Togna, K .A.

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduce heat loss" 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

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

DOE Green Energy (OSTI)

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

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

1981-11-08T23:59:59.000Z

442

Colorado State University program for developing, testing, evaluating and optimizing solar heating and cooling systems. Project status report, March--May 1993  

DOE Green Energy (OSTI)

Results of heat loss tests for the Integral Collector Storage unit are shown. Work on unique solar system components is summarized briefly.

Not Available

1993-06-01T23:59:59.000Z

443

Induction machine stray loss from inter-bar currents  

E-Print Network (OSTI)

Stray load loss refers generally to the sources of induction machine loss not accounted for by typical calculations of primary or secondary copper loss, no load core loss, or friction and windage loss. Harmonic rotor bar ...

Englebretson, Steven Carl

2009-01-01T23:59:59.000Z

444

Stewarding a Reduced Stockpile  

Science Conference Proceedings (OSTI)

The future of the US nuclear arsenal continues to be guided by two distinct drivers: the preservation of world peace and the prevention of further proliferation through our extended deterrent umbrella. Timely implementation of US nuclear policy decisions depends, in part, on the current state of stockpile weapons, their delivery systems, and the supporting infrastructure within the Department of Defense (DoD) and the Department of Energy's National Nuclear Security Administration (NNSA). In turn, the present is a product of past choices and world events. Now more than ever, the nuclear weapons program must respond to the changing global security environment and to increasing budget pressures with innovation and sound investments. As the nation transitions to a reduced stockpile, the successes of the Stockpile Stewardship Program (SSP) present options to transition to a sustainable complex better suited to stockpile size, national strategic goals and budgetary realities. Under any stockpile size, we must maintain essential human capital, forefront capabilities, and have a right-sized effective production capacity. We present new concepts for maintaining high confidence at low stockpile numbers and to effectively eliminate the reserve weapons within an optimized complex. We, as a nation, have choices to make on how we will achieve a credible 21st century deterrent.

Goodwin, B T; Mara, G

2008-04-18T23:59:59.000Z

445

Tips: Natural Gas and Oil Heating Systems | Department of Energy  

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

Natural Gas and Oil Heating Systems Natural Gas and Oil Heating Systems Tips: Natural Gas and Oil Heating Systems May 30, 2012 - 5:41pm Addthis Install a new energy-efficient furnace to save money over the long term. Install a new energy-efficient furnace to save money over the long term. If you plan to buy a new heating system, ask your local utility or state energy office about the latest technologies on the market. For example, many newer models have designs for burners and heat exchangers that are more efficient during operation and cut heat loss when the equipment is off. Consider a sealed-combustion furnace -- they are safer and more efficient. Long-Term Savings Tip Install a new energy-efficient furnace to save money over the long term. Look for the ENERGY STAR® and EnergyGuide labels to compare efficiency and

446

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

447

Energy Basics: Geothermal Heat Pumps  

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

EERE: Energy Basics Geothermal Heat Pumps Geothermal heat pumps use the constant temperature of the earth as an exchange medium for heat. Although many parts of the country...

448

On the Information Loss in Static Systems  

E-Print Network (OSTI)

In this work we give a concise definition of information loss from a system-theoretic point of view. Based on this definition, we analyze the information loss in static input-output systems subject to a continuous-valued input. For a certain class of multiple-input, multiple-output systems the information loss is quantified. An interpretation of this loss is accompanied by upper bounds which are simple to evaluate. Finally, a class of systems is identified for which the information loss is necessarily infinite. Quantizers and limiters are shown to belong to this class.

Geiger, Bernhard C

2011-01-01T23:59:59.000Z

449

Tips: Passive Solar Heating and Cooling | Department of Energy  

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

Tips: Passive Solar Heating and Cooling Tips: Passive Solar Heating and Cooling Tips: Passive Solar Heating and Cooling April 24, 2012 - 4:18pm Addthis Tips: Passive Solar Heating and Cooling Using passive solar design to heat and cool your home can be both environmentally friendly and cost effective. In many cases, your heating costs can be reduced to less than half the cost of heating a typical home. Passive solar design can also help lower your cooling costs. Passive solar cooling techniques include carefully designed overhangs and using reflective coatings on windows, exterior walls, and roofs. Newer techniques include placing large, insulated windows on south-facing walls and putting thermal mass, such as a concrete slab floor or a heat-absorbing wall, close to the windows. A passive solar house requires careful design and siting, which vary by

450

Tips: Passive Solar Heating and Cooling | Department of Energy  

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

Passive Solar Heating and Cooling Passive Solar Heating and Cooling Tips: Passive Solar Heating and Cooling April 24, 2012 - 4:18pm Addthis Tips: Passive Solar Heating and Cooling Using passive solar design to heat and cool your home can be both environmentally friendly and cost effective. In many cases, your heating costs can be reduced to less than half the cost of heating a typical home. Passive solar design can also help lower your cooling costs. Passive solar cooling techniques include carefully designed overhangs and using reflective coatings on windows, exterior walls, and roofs. Newer techniques include placing large, insulated windows on south-facing walls and putting thermal mass, such as a concrete slab floor or a heat-absorbing wall, close to the windows. A passive solar house requires careful design and siting, which vary by

451

HVAC Optimized Heat Exchangers Research Project | Department of Energy  

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

Optimized Heat Exchangers Research Optimized Heat Exchangers Research Project HVAC Optimized Heat Exchangers Research Project The U.S. Department of Energy is currently conducting research into heating, ventilation, and air conditioning (HVAC) optimized heat exchangers. The information generated in this study will demonstrate performance improvements that can be achieved through optimization of refrigerant circuitry for non-uniform inlet air distribution. The tubing circuitry on fin-tube heat exchangers used in residential space-conditioning systems is typically designed assuming uniform airflow through the finned passageways. However, the air flow in installed systems is highly non-uniform, resulting in mismatched refrigerant-air heat transfer that reduces the capacity of the heat exchanger and efficiency of

452

Thermodynamic Analysis of Combined Cycle District Heating System  

E-Print Network (OSTI)

This paper presents a thermodynamic analysis of the University of Massachusetts' Combined Heat and Power (CHP) District Heating System. Energy and exergy analyses are performed based on the first and second laws of thermodynamics for power generation systems that include a 10 MW Solar combustion gas turbine, a 4-MW steam turbine, a 100,000 pph heat recovery steam generator (HRSG), three 125,000 pph package boilers, and auxiliary equipment. In the analysis, actual system data is used to assess the district heating system performance, energy and exergy efficiencies, exergetic improvement potential and exergy losses. Energy and exergy calculations are conducted for the whole year on an hourly basis. System efficiencies are calculated for a wide range of component operating loads. The results show how thermodynamic analysis can be used to identify the magnitudes and location of energy losses in order to improve the existing system, processes or components.

Suresh, S.; Gopalakrishnan, H.; Kosanovic, D.

2011-01-01T23:59:59.000Z

453

Heat treatment of cathodic arc deposited amorphous hard carbon films  

SciTech Connect

Amorphous hard carbon films of varying sp{sup 2}/sp{sup 3} fractions have been deposited on Si using filtered cathodic are deposition with pulsed biasing. The films were heat treated in air up to 550 C. Raman investigation and nanoindentation were performed to study the modification of the films caused by the heat treatment. It was found that films containing a high sp{sup 3} fraction sustain their hardness for temperatures at least up to 400 C, their structure for temperatures up to 500 C, and show a low thickness loss during heat treatment. Films containing at low sp{sup 3} fraction graphitize during the heat treatment, show changes in structure and hardness, and a considerable thickness loss.

Anders, S.; Ager, J.W. III; Brown, I.G. [and others

1997-02-01T23:59:59.000Z

454

United States Department of Energy Thermally Activated Heat Pump Program  

Science Conference Proceedings (OSTI)

The US Department of Energy (DOE) is working with partners from the gas heating and cooling industry to improve energy efficiency using advance absorption technologies, to eliminate chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), to reduce global warming through more efficient combustion of natural gas, and to impact electric peak demand of air conditioning. To assist industry in developing these gas heating and cooling absorption technologies, the US DOE sponsors the Thermally Activated Heat Pump Program. It is divided into five key activities, addressing residential gas absorption heat pumps, large commercial chillers, advanced absorption fluids, computer-aided design, and advanced ``Hi-Cool`` heat pumps.

Fiskum, R.J. [USDOE, Washington, DC (United States); Adcock, P.W.; DeVault, R.C. [Oak Ridge National Lab., TN (United States)

1996-06-01T23:59:59.000Z

455

FETC Programs for Reducing Greenhouse Gas Emissions  

SciTech Connect

Mark Twain once quipped that everyone talks about the weather but no one does anything about it. With interest in global climate change on the rise, researchers in the fossil-energy sector are feeling the heat to provide new technology to permit continued use of fossil fuels but with reduced emissions of so-called `greenhouse gases.` Three important greenhouse gases, carbon dioxide, methane, and nitrous oxide, are released to the atmosphere in the course of recovering and combusting fossil fuels. Their importance for trapping radiation, called forcing, is in the order given. In this report, we briefly review how greenhouse gases cause forcing and why this has a warming effect on the Earth`s atmosphere. Then we discuss programs underway at FETC that are aimed at reducing emissions of methane and carbon dioxide.

Ruether, J.A.

1998-02-01T23:59:59.000Z

456

Applied heat transfer  

Science Conference Proceedings (OSTI)

Heat transfer principles are discussed with emphasis on the practical aspects of the problems. Correlations for heat transfer and pressure drop from several worldwide sources for flow inside and outside of tubes, including finned tubes are presented, along with design and performance calculations of heat exchangers economizers, air heaters, condensers, waste-heat boilers, fired heaters, superheaters, and boiler furnaces. Vibration analysis for tube bundles and heat exchangers are also discussed, as are estimating gas-mixture properties at atmospheric and elevated pressures and life-cycle costing techniques. (JMT)

Ganapathy, V.

1982-01-01T23:59:59.000Z

457

Plasma heat pump and heat engine  

Science Conference Proceedings (OSTI)

A model system where cold charged particles are locally confined in a volume V{sub P} within a warm plasma of volume V (V{sub P}kilowatts is possible with the present day technology. Second, we discuss the feasibility of constructing an electrostatic heat engine which converts plasma heat into mechanical work via plasma electric fields. Effects of P{sub E} are shown to be observable in colloidal solutions.

Avinash, K. [Centre for Space Plasma and Aeronomic Research, University of Alabama, Huntsville, Alabama 35899 (United States) and Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

2010-08-15T23:59:59.000Z

458

TF Ripple Loss of Alpha Particles from the ITER Interim Design: Simulation and Theory  

E-Print Network (OSTI)

a , R. J. Goldston a , R. B. White a , R. V. Budny a , D. C. McCune a , C. O. Miller b , S. J. Zweben heating and potentially severe localized wall damage in fusion reactors. In this paper we show guiding loss criterion, substantial ad hoc normalization factors were required. This is understandable, since

459

Comparative evaluation of the impacts of domestic gas and electric heat pump heating on air pollution in California  

SciTech Connect

Residential space and water heating accounts for approximately 12% of California's and 15% of the United States, energy consumption. most Of the residential heating is by direct use of natural gas. combustion of natural gas is a contributor to the overall air pollution,, especially CO and NO{sub x} in the urban areas. Another efficient method for domestic water and space heating is use of electric heat pumps, the most popular category of which uses air as its heat source. Electric heat pumps do not emit air pollutants at the point of use, but use electric power, which is a major contributor to air pollution at its point of generation from fossil fuels. It is the specific objective of this report to evaluate and compare the energy efficiency and source air pollutants of natural gas heaters and electric heat pumps used for domestic heating. Effect of replacing natural gas heaters with electric heat pumps on air pollutant emissions due to domestic heating in two urban areas and in California as a whole has also been evaluated. The analysis shows that with the present state of technology, electric heat pumps have higher heating efficiencies than natural gas heaters. Considering the current electricity generation mix in the US, electric heat pumps produce two to four times more NO{sub x}, much less CO, and comparable amount of CO{sub 2} per unit of useful heating energy compared to natural gas heaters. With California mix, electric heat pumps produce comparable NO{sub x} and much less CO and approximately 30% less CO{sub 2} per unit heat output. Replacement of natural gas heaters with electric heat pumps will slightly increase the overall NO{sub x}, and reduce CO and CO{sub 2} emissions in California. The effect of advanced technology power generation and heat pump heating has also been analyzed.

Ganji, A. (San Francisco State Univ., CA (United States). Div. of Engineering)

1992-07-01T23:59:59.000Z

460

Comparative evaluation of the impacts of domestic gas and electric heat pump heating on air pollution in California. Final report  

SciTech Connect

Residential space and water heating accounts for approximately 12% of California`s and 15% of the United States, energy consumption. most Of the residential heating is by direct use of natural gas. combustion of natural gas is a contributor to the overall air pollution,, especially CO and NO{sub x} in the urban areas. Another efficient method for domestic water and space heating is use of electric heat pumps, the most popular category of which uses air as its heat source. Electric heat pumps do not emit air pollutants at the point of use, but use electric power, which is a major contributor to air pollution at its point of generation from fossil fuels. It is the specific objective of this report to evaluate and compare the energy efficiency and source air pollutants of natural gas heaters and electric heat pumps used for domestic heating. Effect of replacing natural gas heaters with electric heat pumps on air pollutant emissions due to domestic heating in two urban areas and in California as a whole has also been evaluated. The analysis shows that with the present state of technology, electric heat pumps have higher heating efficiencies than natural gas heaters. Considering the current electricity generation mix in the US, electric heat pumps produce two to four times more NO{sub x}, much less CO, and comparable amount of CO{sub 2} per unit of useful heating energy compared to natural gas heaters. With California mix, electric heat pumps produce comparable NO{sub x} and much less CO and approximately 30% less CO{sub 2} per unit heat output. Replacement of natural gas heaters with electric heat pumps will slightly increase the overall NO{sub x}, and reduce CO and CO{sub 2} emissions in California. The effect of advanced technology power generation and heat pump heating has also been analyzed.

Ganji, A. [San Francisco State Univ., CA (United States). Div. of Engineering

1992-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduce heat loss" 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.