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1

Heat storage medium of moistened NA2HPO4. 12H20 and method of a preparation thereof  

Microsoft Academic Search

Na2HPO4.12H2O is prevented from deteriorating as a heat storage medium after repeated cycles of heat storage and heat withdrawal resulting from precipitation of dehydrated forms of the salt by mixing thoroughly into the dodecahydrate material a small water content up to 5% of the mixture by weight, after which the material is heated above the melting point of the dodecahydrate

W. Friderichs-weinle; P. Friderichs

1981-01-01

2

Heat storage systems  

Microsoft Academic Search

The present invention provides systems for transfer of heat such as useful in solar energy systems. A heat storage medium is used, preferably salt conditioned by anticaking anti-corrosive treatment whereby hydrated salts have increased utility by remaining granular during severe temperature and humidity changes, permitting the salt to be used more effectively as a heat storage and exchange medium. The

Dumbeck

1979-01-01

3

Low-cost central receiver solar power plant using molten salt as a heat transfer and storage medium  

Microsoft Academic Search

The paper proposes an alternative approach to solar thermal power plants to reduce the electricity cost relative to the first generation water\\/steam systems. The cost reduction is achieved by generating a 950 F 2400 psig steam by pumping an eutectic salt mixture of sodium nitrate and potassium nitrate as the heat transfer and storage medium to the steam generator and\\/or

T. R. Tracey

1979-01-01

4

Latent heat storage  

NASA Astrophysics Data System (ADS)

The investigations of materials presumably suitable as storage media for latent heat indicate that water, some salt hydrates and eutectic mixtures of water and salt hydrates possess extreme heats of fusion. Their melting points, ranging from about -50 to +130 C, fit well for storing low grade heat in residential energy systems. Detailed experimental investigations on a large number of these media show, however, that only a few of them satisfy the quality requirements for practical application in storage units. Flexible flat-plate storage containers especially developed for selected salt hydrates which expand on melting also show satisfactory performance over long periods of operation. In the case of water and selected water-salt hydrate eutectics the volume increases on solidification, and the expansion of solid storage material, being very inhomogeneous, breaks even flexible containers after only a few storage cycles. This ruinous local expansion can be avoided, however, by adding a small amount of special, lower melting salt hydrate eutectics which homogenize the crystallization and solidification of the storage medium.

Schroeder, J.; Gawron, K.

1981-06-01

5

Heat storage material  

SciTech Connect

When strontium oxide is applied as a nucleating agent to calcium chloride-hexahydrate as a heat storage material, a supercooling phenomenon of the resulting heat storage material can be suppressed to be slight.

Yanadori, M.; Miyamoto, S.

1984-08-14

6

HEATS: Thermal Energy Storage  

SciTech Connect

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

None

2012-01-01

7

Heat storage material  

SciTech Connect

A heat storage material to be used for air cooling systems is provided. This heat storage material comprises acetic acid or a mixture of acetic acid and one or more acetates and is further added with at least one anhydrous halide as nucleating agent to prevent supercooling.

Kamohara, H.; Koike, K.; Miyamoto, S.; Yanadori, M.

1985-05-21

8

Heat storage system adapted for incongruently melting heat storage materials and congruently melting heat storage materials  

Microsoft Academic Search

A heat storage article adapted for prevention of stratification of incongruently melting heat storage materials, such as eutectic salts, and adapted for use with congruently melting heat storage materials, such as paraffins. The article is comprised of a concrete stone composition, a certain portion of which is comprised of metallic heat transfer materials in order to increase heat transfer through

Schoenfelder

1980-01-01

9

Solar Energy: Heat Storage.  

ERIC Educational Resources Information Center

|This module on heat storage is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy technologies. The…

Knapp, Henry H., III

10

Solar Energy: Heat Storage.  

ERIC Educational Resources Information Center

This module on heat storage is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy technologies. The module…

Knapp, Henry H., III

11

Isothermal Solar Heat Storage Materials.  

National Technical Information Service (NTIS)

A group of over 200 potential phase change heat storage materials, melting from 10-90C was identified. Laboratory tests narrowed these to materials recommended for hot faucet water, hydronic heating, forced air heating, heat pump application, radiant wall...

G. A. Lane J. S. Best

1975-01-01

12

Heat Transfer Mediums les Fluides Caloporteurs.  

National Technical Information Service (NTIS)

Different mediums (gas, vapor, liquid) most commonly employed in industry for heat transfer are discussed. Data pertaining to the various properties of these mediums are presented. Criteria for choosing a medium are given together with the medium most com...

J. P. Allard

1977-01-01

13

Investigation of Latent Heat Storage Materials in the Medium and High Temperature Range (Untersuchung von Mittel- und Hochtemperaturlatentwaermespeicher-Materialien. Abschlussbericht).  

National Technical Information Service (NTIS)

Two temperature ranges were considered for latent heat storage systems based on inorganic salts. Structural materials and their corrosion resistance, chemical and physical properties of the salts, and economic criteria were considered. Because none of the...

D. Heine F. Heess D. Stiener I. K. E. Stuttgart

1981-01-01

14

Heat storage in alloy transformations  

NASA Astrophysics Data System (ADS)

Heat storage was approached in the following four directions: (1) calorimetric measurements of heats of eutectic transformation and heat capacities of solid and liquid mixtures to determine the maximum heat storage capability; (2) volume changes during transformation and thermal expansion below, and above the transformation temperature as measured by X-ray absorption; (3) the use of graphite and carbides, successful bulk containers, as coatings to protect steels against attack by the heat storage alloys; and (4) heat flow models for simple heat exchanger geometries to show the advantage of alloys over salts for fast storage.

Birchenall, C. E.

1981-03-01

15

Experience of Heat Storage in a Stone Heat Store.  

National Technical Information Service (NTIS)

Why the use of stone as a heat storage medium has been considered at all is due to the materials generally ready availability and good chemical stability. The price of a stone heat store can be kept relatively low. However, the number of problems and unde...

N. Dafgaard G. Werner

1983-01-01

16

Low temperature latent heat thermal energy storage - Heat storage materials  

Microsoft Academic Search

Heat-of-fusion storage materials for low temperature latent heat storage in the temperature range 0-120 C are reviewed. Organic and inorganic heat storage materials classified as paraffins, fatty acids, inorganic salt hydrates and eutectic compounds are considered. The melting and freezing behavior of the various substances is investigated using the techniques of Thermal Analysis and Differential Scanning Calorimetry. The importance of

A. Abhat

1983-01-01

17

Low temperature latent heat thermal energy storage - Heat storage materials  

NASA Astrophysics Data System (ADS)

Heat-of-fusion storage materials for low temperature latent heat storage in the temperature range 0-120 C are reviewed. Organic and inorganic heat storage materials classified as paraffins, fatty acids, inorganic salt hydrates and eutectic compounds are considered. The melting and freezing behavior of the various substances is investigated using the techniques of Thermal Analysis and Differential Scanning Calorimetry. The importance of thermal cycling tests for establishing the long-term stability of the storage materials is discussed. Finally, some data pertaining to the corrosion compatibility of heat-of-fusion substances with conventional materials of construction is presented.

Abhat, A.

18

Characterization of Alkanes and Paraffin Waxes for Application as Phase Change Energy Storage Medium  

Microsoft Academic Search

Latent thermal energy storage is one of the favorable kinds of thermal energy storage methods considered for renewable energy source utilization, as in solar photothermal systems. Heat is stored mostly by means of the latent heat of phase change of the medium. The temperature of the medium remains more or less constant during the phase transition. A large number of

SYUKRI HIMRAN; ARYADI SUWONO; G. ALI MANSOORI

1994-01-01

19

Solar cooker with latent heat storage: Design and experimental testing  

Microsoft Academic Search

A box-type solar cooker with latent heat storage has been designed and fabricated for the composite climatic conditions of India. The experimental results demonstrate the feasibility of using a phase change material as the storage medium in solar cookers, i.e. it is possible to cook the food even in the evening with a solar cooker having latent heat storage. It

D. Buddhi; L. K. Sahoo

1997-01-01

20

The use of refrigerants for reflux boiling direct contact heat exchanging in heat-of-fusion storage using salt hydrates  

Microsoft Academic Search

As was early proposed by Carlsson, Stymne and Wettermark certain refrigerants can be used as media for reflux boiling direct contact heat exchanging in heat-of-fusion storage using salt hydrates. Suitable couples of storage medium and heat transfer medium are those for which the two liquids are immiscible and the density of the liquid phase of the heat transfer medium is

B. Carlsson; A. Schmidt

1983-01-01

21

Storage of low-temperature heat in salt-hydrate melts: Calcium chloride hexahydrate  

Microsoft Academic Search

Topics covered include: storage of low-temperature heat in melts; chloride hexahydrate as a heat storage medium; methods of adapting CaCl2.6H2O for use as a heat storage medium-investigations of the chemical solubility properties of the CaCl2; H2O system; heat transfer characteristics of a heat of fusion storage system based on calcium chloride hexahydrate; and the development and construction of a heat

B. Carlsson; H. Stymne; G. Wettermark

1978-01-01

22

Heat storage material  

SciTech Connect

A heat storage material comprises NaCH/sub 3/COO.3H/sub 2/O as a main component and a nucleating agent comprising 95 to 10 wt. % of anhydrous sodium acetate and 5 to 90 wt. % of at least one of the other sodium salts selected from the group consisting of Na/sub 3/PO/sub 4/, Na/sub 2/HPO/sub 4/, NaH/sub 2/PO/sub 4/, NaNH/sub 4/PO/sub 4/.4H/sub 2/O, Na/sub 5/P/sub 3/O/sub 10/, C/sub 6/H/sub 5/Na/sub 2/PO/sub 4/.2H/sub 2/O, NaBO/sub 2/.2H/sub 2/O, Na/sub 2/B/sub 4/O/sub 7/.10H/sub 2/O, Na/sub 2/C/sub 2/O/sub 4/, NaBr, NaCl, CH/sub 2/(COONa)/sub 2/.H/sub 2/O, (CHCOONa)/sub 2/.H/sub 2/O, (CH/sub 2/COONa)/sub 2/.6H/sub 2/O, HOC(CH/sub 2/)/sub 2/(COONa)/sub 2/.2H/sub 2/O, CH/sub 3/(CH/sub 2/)/sub 2/COONa, CH/sub 3/(CH/sub 2/)/sub 6/COONa, HOOCCH(NH/sub 2/)(CH/sub 2/)/sub 2/COONa.H/sub 2/O sodium oleate, and sodium stearate.

Kimura, H.; Kai, J.

1983-08-23

23

Storage of Low Temperature Heat: Solar Energy Thermal Storage.  

National Technical Information Service (NTIS)

The major means available for thermal storage of solar energy are reviewed. The general conditions for heat storage are discussed. The various types of sensible and latent heat storage are covered. (ERA citation 03:008230)

G. Wettermark J. Kowalewska

1976-01-01

24

Heat storage technology update  

Microsoft Academic Search

One way to reduce vehicle cold-start emissions of unburned fuel is to reduce catalyst light-off time. The U.S. Environmental Protection Agency (EPA) has evaluated several electrically heated catalyst (EHC) technologies with favorable results at ambient temperatures of 24C and [minus]7C. The resistive heating elements reduce the time during which the catalyst remains ineffective because of insufficient warming by the cold

K. H. Hellman; G. K. Piotrowski; R. M. Schaefer

1993-01-01

25

Data storage device having a phase change memory medium reversible by direct overwrite and method of direct overwrite  

Microsoft Academic Search

This patent describes a method of storing data in individual memory cells of a data storage disc having a layer of non-ablative, reversible, phase change data storage medium between adjacent heat sink layers, the data storage medium. It comprises: a miscible telluride-selenide solid solution having a crystallization time of less than 1 microsecond and chosen from the group consisting of:

1990-01-01

26

Periodic heat transfer through an inhomogeneous medium  

NASA Astrophysics Data System (ADS)

One dimensional heat conduction equation has been investigated for periodic heat transfer in an inhomogeneous bounded medium. Exact analytical solutions for some typical thermal conductivity profiles have been obtained. Also an approximate solution has been attempted for the first time for heat conduction problems which is applicable for any arbitrary variation of thermal conductivity. Numerical appreciation for a parabolic thermal conductivity profile shows that results from approximate approach are in excellent agreement with those obtained by the exact analytical approach.

Balla, M. Y.

1985-10-01

27

A solar heating system with annual storage  

NASA Astrophysics Data System (ADS)

A solar heated house with long term storage capability, built in Trento, Italy, is described. The one story house was built from modular components and has a total heated volume of 1130 cu m. Flat plate solar collectors with a water-antifreeze medium are located beneath the lawn, and six cylindrical underground tanks holding 130 cu m of water heated by thermal energy from the collectors are situated under the garden. The house walls have an 8 cm cavity filled with 5 cm of formaldehyde foam, yielding a heat transmission (U) of 0.37 W/sq m/deg C. The roof and ceilings are insulated with fiberglass and concrete, producing U-values of 0.46 W/sq m/deg C and 0.57 W/sq m/deg C, respectively. Heat pumps using 6 kW move thermal energy between the house and the tanks. Direct hot water heating occurs in the summer, and direct home heating when the stored water temperature exceeds 32 C. A computer model was developed which traces the annual heat flow and it is shown that the system supplies all heating requirements for the house, with electrical requirements equal to 20 percent of the annual house needs.

Lazzari, F.; Raffellini, G.

1981-07-01

28

Characterization of refrigerant - 12 gas hydrate formation for heat pump cool storage applications  

Microsoft Academic Search

A latent cool storage system for load management applications is currently under development at Oak Ridge National Laboratory. This system utilizes a refrigerant gas hydrate as the storage medium and incorporates storage directly into the heat pump cycle. This paper reviews the chemistry of gas hydrates, describes the conceptual heat pump\\/cool storage system, and presents the results from experiments performed

1984-01-01

29

Experimental characterization of the thermal performance of a heat-of-fusion storage unit  

Microsoft Academic Search

Experimentally determined thermal performance data are presented for a heat-of-fusion storage unit based on 200 kg of calcium chloride hexahydrate. Constructed as a tube heat exchanger, the unit has a storage medium encapsulated in vertical tubes. Conditions are chosen for their relevance to the application of short-term storage of solar heat, and the heat-of-fusion storage unit is discussed in relation

B. Carlsson; A. Schmidt; A. Gyorki; H. Stymne; G. Wettermark

1980-01-01

30

Ground heat storage with solar in Sweden  

Microsoft Academic Search

Two experimental projects in Sweden, which are now using unusual forms of ground heat storage with solar energy, have led to more development in ground heat storage in Sweden. Two of the initial projects, which were funded by the Swedish government, are in operation near Kungsbacka, Sweden. Both utilize ground storage networks with either plastic piping and both are expected

A. F. Friedlander; S. Olsson

1983-01-01

31

Examination of heat storage in soil  

NASA Astrophysics Data System (ADS)

The performance of a heat storage system, based on soil storage by spherical temperature stratification, was assessed and compared to conventional hot water systems for usage in single family houses heated by solar energy. A heat conduction code was used in combination with a simulation model for solar room heating systems in order to evaluate the dependence of storage performance on soil materials, heat transfer parameters, and storage size. Results show that the initially suggested storage scheme should be supplemented with insulation in order to perform somewhat better than hot water storage. A more definite assessment requires further studies on transmission losses, heat capacity enlargement, and mechanical stability and aging properties of insulation materials.

Jaeger, F.; Reichert, J.; Herz, H.

1981-11-01

32

Olivine-based heat storage refractories  

NASA Astrophysics Data System (ADS)

The processing properties and performance of special refractory shapes produced from olivine for prototype evaluations in heat storage furnaces are investigated. Heat storage furnaces and related consumer owned thermal storage units are energy conversion/storage devices of the sensible heat type. Their primary purpose is to permit electrical load leveling of large generating/distributing systems. Load-leveling enables power generating plants to operate more efficiency thus contributing to better overall energy utilization. The principal application for these ceramic thermal energy reservoirs is in home or business heating (furnaces, space heaters).

Gay, B. M.; Palmour, H., III; Cochrane, R. L.

1981-03-01

33

Data storage device having a phase change memory medium reversible by direct overwrite and method of direct overwrite  

SciTech Connect

This patent describes a method of storing data in individual memory cells of a data storage disc having a layer of non-ablative, reversible, phase change data storage medium between adjacent heat sink layers, the data storage medium. It comprises: a miscible telluride-selenide solid solution having a crystallization time of less than 1 microsecond and chosen from the group consisting of: arsenic telluride-arsenic selenide; antimony telluride-antimony selenide; bismuth telluride-bismuth selenide; and mixtures thereof.

Strand, D.

1990-05-08

34

Method of implicit partitioning the storage space available on a storage medium  

US Patent & Trademark Office Database

A method and apparatus for implicitly partitioning the storage space available on a storage medium, to a storage medium for storing user data and to a recording device for storing user data on a storage medium. In order to limit the mount/unmount time of a volume like a UDF volume on a magnetic tape for ADR and to limit overall seek times during reading: a) storage space available for storage on the medium is divided into a directory region and a data region, b) metadata are stored in the directory region, c) user data are stored in the data region being implicitly subdivided into data sub-regions, d) file set data for user data stored in a data sub-region are stored in a corresponding directory sub-region being assigned to this data sub-region, and e) borders and size of data sub-regions are variable.

2005-03-15

35

The use of refrigerants for reflux boiling direct contact heat exchanging in heat-of-fusion storage using salt hydrates  

SciTech Connect

As was early proposed by Carlsson, Stymne and Wettermark certain refrigerants can be used as media for reflux boiling direct contact heat exchanging in heat-of-fusion storage using salt hydrates. Suitable couples of storage medium and heat transfer medium are those for which the two liquids are immiscible and the density of the liquid phase of the heat transfer medium is higher than that of the liquid phase of the storage medium. The combinations of the salt hydrate calcium chloride hexahydrate, m.p. 30/sup 0/C, and the two refrigerants R113 and R12B1 meet these requirements and were previously studied by Carlsson and Schmidt who found R12B1 to be a more favourable heat transfer medium than R113 when combined with the pertinent salt hydrate. Arrhenius et al. have considered several couples of storage medium and heat transfer medium for latent heat exchange by direct contact vapourization. The refrigerant R11 and the sodium acetate trihydrate, which meet the density requirements mentioned above, are reported to be of particular interest. The present paper summarizes the results from a study where the two couples of the salt hydrate calcium chloride hexahydrate and the refrigerant R12B1 and that of sodium thiosulphate pentahydrate, m.p. 48/sup 0/C, and R12B1 are investigated. The aim is to clarify the technical benefits of this heat exchange method in comparison to other types of heat exchange techniques.

Carlsson, B.; Schmidt, A.

1983-12-01

36

Experimental studies on the behaviours of hydride heat storage system  

NASA Astrophysics Data System (ADS)

Experimental examinations and a lumped system model are used to describe the heat transfer characteristics in the design of a single tube type metal hydride heat storage vessel. The apparatus studied was fed heat by water vaporized by an electric furnance with a 3 kWh x 2 capacity. An annular tube in the middle of the reactor vessel contained the metal hydride (Mg2Ni), which was washed with hydrogen gas. Measurements were taken of the heat transfer medium temperature, H2 flow rate, and temperature responses at sites in the hydride bed. The numerical model was constructed assuming that no pressure gradient was present in the heat storage medium bed, the temperature was uniform throughout the bed, and material characteristics were independent of pressure and temperature encountered. The bed temperature was found to be uniform in the generation and absorption phases, although the latter took longer to stabilize. The lumped parameter model developed is shown to acceptably model the performance of a single tube type heat storage vessel in terms of heat transfer efficiency.

Kawamura, M.; Ono, S.; Higano, S.

37

Free convection in a heat-generating porous medium in a finite vertical cylinder  

Microsoft Academic Search

Fluid currents formed in a fluid-saturated porous medium during convective heat transfer have many important applications, such as oil and gas production, cereal grain storage, geothermal energy, and porous insulation. This investigation considers the numerical solution of the steady-state streamlines and isotherms formed by the convective and conduction heat transfer in an air-solid porous medium in an enclosed, short, vertical

W. E. Jr. Stewart; C. L. G. Dona

1988-01-01

38

Storage of heat: A survey of efforts and possibilities  

Microsoft Academic Search

Various methods are described for storing heat. Topic areas discussed include the following: the role of heat storage in different energy systems; heat storage with passive and active solar heat systems; sensible heat; latent heat - phase change; thermochemical reactions; the American program for storage of heat.

G. Wettermark; B. Carlsson; H. Stymne

1979-01-01

39

Parametric study of rock pile thermal storage for solar heating and cooling phase 1  

Microsoft Academic Search

The test data and an analysis were presented, of heat transfer characteristics of a solar thermal energy storage bed utilizing water filled cans as the energy storage medium. An attempt was made to optimize can size, can arrangement, and bed flow rates by experimental and analytical means. Liquid filled cans, as storage media, utilize benefits of both solids like rocks,

H. Saha

1977-01-01

40

High temperature active heat exchanger research for latent heat storage  

Microsoft Academic Search

An active heat exchange method in a latent heat (salt) thermal energy storage system that prevents a low conductivity solid salt layer from forming on heat transfer surfaces was developed. An evaluation of suitable media with melting points in the temperature range of interest (250 to 400 C) limited the candidates to molten salts from the chloride, hydroxide and nitrate

J. Alario; R. Haslett

1982-01-01

41

Fusible pellet transport and storage of heat  

NASA Astrophysics Data System (ADS)

A new concept for both transport and storage of heat at high temperatures and heat fluxes is introduced and the first steps in analysis of its feasibility is taken. The concept utilizes the high energy storage capability of materials undergoing change of phase. The phase change material, for example a salt, is encapsulated in corrosion resistant sealed pellets and transported in a carrier fluid to heat source and storage. Calculations for heat transport from a typical solar collector indicate that the pellet mass flow rates are relatively small and that the required pumping power is only a small fraction of the energy transport capability of the system. Salts and eutectic salt mixtures as candidate phase change materials are examined and discussed. Finally, the time periods for melting or solidification of sodium chloride pellets is investigated and reported.

Bahrami, P. A.

1982-06-01

42

Heat transfer study of a heat storage container with a phase change material. (Part 2. Heat transfer in the melting process in a cylindrical heat storage container)  

Microsoft Academic Search

Calcium chloride hexahydrate as a latent-heat storage material is placed in a vertical cylindrical heat storage container, and a vertical single pipe for heat transfer purpose is also inserted in the container. In this setup, the heat transfer rates during melting of the heat storage material is largely influenced by natural convection at the melting liquid layer section. Also, regarding

Michio Yanadori; Takashi Masuda

1989-01-01

43

An Assessment of Nuclear Isomers as an Energy Storage Medium  

SciTech Connect

Nuclear Isomers have been suggested as a potential high energy density medium that might be used to store energy. This talk assesses the state of the science supporting key elements of using nuclear isomers in energy storage applications. The focus is on the nuclear isomer {sup 178m2}Hf which has been most widely suggested for energy storage applications. However, the science issues apply to all nuclear isomer. The assessment addresses the production of the nuclear isomer, and inducing the release of the isomer. Also discussed are novel speculations on photon and/or neutron chain reactions, both as a 'pure' material as well as mixed with other materials.

Hartouni, E P

2008-12-08

44

Sulfuric acid-sulfur heat storage cycle  

DOEpatents

A method of storing heat is provided utilizing a chemical cycle which interconverts sulfuric acid and sulfur. The method can be used to levelize the energy obtained from intermittent heat sources, such as solar collectors. Dilute sulfuric acid is concentrated by evaporation of water, and the concentrated sulfuric acid is boiled and decomposed using intense heat from the heat source, forming sulfur dioxide and oxygen. The sulfur dioxide is reacted with water in a disproportionation reaction yielding dilute sulfuric acid, which is recycled, and elemental sulfur. The sulfur has substantial potential chemical energy and represents the storage of a significant portion of the energy obtained from the heat source. The sulfur is burned whenever required to release the stored energy. A particularly advantageous use of the heat storage method is in conjunction with a solar-powered facility which uses the Bunsen reaction in a water-splitting process. The energy storage method is used to levelize the availability of solar energy while some of the sulfur dioxide produced in the heat storage reactions is converted to sulfuric acid in the Bunsen reaction.

Norman, John H. (LaJolla, CA)

1983-12-20

45

Building structure with heat storage and recovery  

Microsoft Academic Search

In US Pat. No. 4,054,246, a double-walled structure collects solar heat with air as the heat transfer medium, the heat is subsequently stored in subterranean gravel pits. In the present invention (1) the design of the gravel pits is improved, (2) the efficiency of the solar collectors is improved, whereby needed collection area is reduced, (3) seepage into the pits

Johnson

1979-01-01

46

Advanced Heat Transfer and Thermal Storage Fluids  

SciTech Connect

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

Moens, L.; Blake, D.

2005-01-01

47

Thermodynamic efficiency of pumped heat electricity storage.  

PubMed

Pumped heat electricity storage (PHES) has been recently suggested as a potential solution to the large-scale energy storage problem. PHES requires neither underground caverns as compressed air energy storage (CAES) nor kilometer-sized water reservoirs like pumped hydrostorage and can therefore be constructed anywhere in the world. However, since no large PHES system exists yet, and theoretical predictions are scarce, the efficiency of such systems is unknown. Here we formulate a simple thermodynamic model that predicts the efficiency of PHES as a function of the temperature of the thermal energy storage at maximum output power. The resulting equation is free of adjustable parameters and nearly as simple as the well-known Carnot formula. Our theory predicts that for storage temperatures above 400?°C PHES has a higher efficiency than existing CAES and that PHES can even compete with the efficiencies predicted for advanced-adiabatic CAES. PMID:24074066

Thess, André

2013-09-13

48

Thermodynamic Efficiency of Pumped Heat Electricity Storage  

NASA Astrophysics Data System (ADS)

Pumped heat electricity storage (PHES) has been recently suggested as a potential solution to the large-scale energy storage problem. PHES requires neither underground caverns as compressed air energy storage (CAES) nor kilometer-sized water reservoirs like pumped hydrostorage and can therefore be constructed anywhere in the world. However, since no large PHES system exists yet, and theoretical predictions are scarce, the efficiency of such systems is unknown. Here we formulate a simple thermodynamic model that predicts the efficiency of PHES as a function of the temperature of the thermal energy storage at maximum output power. The resulting equation is free of adjustable parameters and nearly as simple as the well-known Carnot formula. Our theory predicts that for storage temperatures above 400°C PHES has a higher efficiency than existing CAES and that PHES can even compete with the efficiencies predicted for advanced-adiabatic CAES.

Thess, André

2013-09-01

49

Latent Heat Storage Materials and Systems: A Review  

Microsoft Academic Search

The use of a latent heat storage system using Phase Change Materials (PCM) is an effective way of storing thermal energy (solar energy, off-peak electricity, industrial waste heat) and has the advantages of high storage density and the isothermal nature of the storage process. It has been demonstrated that, for the development of a latent heat storage system, choice of

S. D. Sharma; Kazunobu Sagara

2005-01-01

50

STABILIZATION OF GLAUBER's SALT FOR LATENT HEAT STORAGE  

Microsoft Academic Search

Thermal energy storage systems (TES) have attracted increasing interest for thermal applications such as hot water, space heating and cooling. These systems are useful to correct the mismatch between the supply and demand of energy. There are mainly two types of thermal energy storage systems, sensible and latent heat storage. Latent heat storage is particularly attractive due to its ability

Özgül GÖK

51

General characteristics of thermochemical heat storage  

Microsoft Academic Search

The research and development on thermochemical heat storage have focused on systems which operate at either a low temperature (approx. 100-150°C or 220-300°F) or a high temperature (approx. 350-500°C or 660-930°F). The low temperature systems are intended primarily for heating and cooling buildings and can be operated with high efficiency, double-glazed flat plate solar collectors or slightly concentrating collectors such

Wentworth

1985-01-01

52

Heat pipe effect in porous medium  

SciTech Connect

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

Joseph, M.

1992-12-01

53

Solar heat transfer and storage system  

SciTech Connect

This patent describes a heat transfer and storage system comprising: (a) a heat storage chamber having a phase change material contained therein; (b) water heater means for containing potable water, and including first conduit means through which the water flows, the first conduit means having a portion thereof extending through the phase change material in the chamber; (c) means for collecting heat energy, and including second conduit means through which a heat transfer liquid flows. The second conduit has a portion thereof extending through the phase change material in the chamber in adjacent parallel relation to the portion of the first conduit means; (d) fin means extending outwardly from the portion of the first and second conduit means to transfer heat between the conduit portions and the phase change material; and (e) connecting means simultaneously holding the portions of the first and second conduit means in adjacent heat conducting relationship to one another and holding the fin means interposed between the portions of the first and second conduit means in a heat conducting relationship therewith.

McCall, D.

1986-11-25

54

German central solar heating plants with seasonal heat storage  

SciTech Connect

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

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

2010-04-15

55

Development of composite latent/sensible heat storage media  

NASA Astrophysics Data System (ADS)

Results of an on-going program to develop a composite latent-sensible thermal energy storage medium, trade marked CompPhase, are presented. The target application area was periodic kiln energy recovery. The concept is that of a composite salt/ceramic material processed such that the medium maintains its shape and mechanical integrity through the salt melting temperature. As such, the media can be fabricated into a variety of shapes suitable for packed beds, fluidized beds, or direct contact heat exchangers. The properties of ten carbonate salt or eutectic mixtures of carbonate salts were reviewed to select the most appropriate candidates for development. Three salts and two ceramic materials were evaluated in laboratory tests to select the final material, a composite of sodium-barium eutectic/magnesium oxide, for development. Two methods of processing the constituent powders for fabrication into storage pellets were developed, and one method was applied to pellet fabrication by commercial processing equipment. Two different preliminary cost estimates bracketed the expected cost of commercially fabricating storage pellets. Also, two modifications to the material processing method were suggested to reduce costs. Thermal cycling was conducted on laboratory produced experimental pellets and on prototype pellets fabricated by commercial processes. Detailed laboratory tests to determine composite mechanical and thermal properties were conducted. It is concluded that further laboratory, field, and economic studies are required before the concept of composite storage media can be considered fully developed for commercialization.

Petri, R.; Ong, E. T.; Kardas, A.

1990-12-01

56

[Effects of storage medium and temperature on short-term storage of Acipenser baerii eggs].  

PubMed

This paper studied the effects of different storage medium (coelomic fluid, Hepes solution, and modified Ringer's solution), temperature (4 degrees C and 16 degrees C), and duration (4 h, 8 h, 16 h, and 24 h) on the short-term storage of Siberian sturgeon (Acipenser baerii) eggs. The results showed that storage medium, temperature, and duration all had significant effects on the fertilization rate, hatching success, and malformation of newly hatched larvae (P < 0.05). With the increase of storage duration, the fertilization and hatching rates decreased, while the malformation rate of hatched larvae increased. The A. baerii eggs stored at 16 degrees C had higher fertilization, hatching, and malformation rates but shorter holding time than those stored at 4 degrees C. The optimal conditions for the short-term storage of A. baerii eggs were Hepes solution prepared according to the biochemical composition of A. baerii coelomic fluid, 16 degrees C, and 4 h, under which, 86.36% fertilization rate, 94.74% hatching rate, and zero malformation would be obtained. PMID:20387448

Zhang, Tao; Yan, Shi-Wei; Zhuang, Ping; Zhang, Long-Zhen; Tian, Mei-Ping; Wang, Bin; Zhang, Da-Hai; Yao, Zhi-Feng

2010-01-01

57

Cooperative heat transfer and ground coupled storage system  

DOEpatents

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

Metz, Philip D. (Rocky Point, NY)

1982-01-01

58

Parametric study of rock pile thermal storage for solar heating and cooling phase 1. Final report. [Water-filled cans  

Microsoft Academic Search

The test data and an analysis were presented, of heat transfer characteristics of a solar thermal energy storage bed utilizing water filled cans as the energy storage medium. An attempt was made to optimize can size, can arrangement, and bed flow rates by experimental and analytical means. Liquid filled cans, as storage media, utilize benefits of both solids like rocks,

Saha

1977-01-01

59

Increasing Soil Heat Storage across Northern Eurasia  

NASA Astrophysics Data System (ADS)

Recent studies have shown that the ocean, atmosphere, cryosphere, and continental land masses have gained heat over the past century [Hansen et al., 2009; Beltrami et al., 2002]. Although soil heat storage may play a lesser role than the ocean in absorbing heat, it plays an important role in identifying and understanding changes in climate, especially relating to changes in the permafrost active layer. Northern Eurasia has experienced some of the strongest warming trends over the twentieth century, and in situ measurements of soil temperature have shown that the land surface is responding by warming accordingly. The observational network presents an incomplete picture of the soil heat gain because the network is sparse and temperature does not account for latent heat effects and moisture dynamics in the soil column, which also affect the change in enthalpy. In the winter, the snowpack insulates the soil column, which may decouple the air and ground temperatures. To bridge this gap in our understanding, we use the VIC land surface model, which solves for both the energy and water budget at the land surface and subsurface with a 50 meter soil column, to calculate the change in ground heat between 1901 and 2005 after a 500-year model spin-up. We find that the heat stored in the soil column experienced a small but steady increase at the beginning of the twentieth century, with an abrupt increase in heat accumulation after 1980, indicating a possible tipping point in the system. There is heterogeneity in the spatial pattern of heat accumulation, with larger accumulation in the southern Ob River basin and the permafrost-dominated regions of Eurasia. The modeled heat accumulation in the permafrost zone confirms concerns in the scientific literature that the permafrost is particularly vulnerable to climate changes.

Troy, T. J.; Wood, E. F.

2009-12-01

60

THERMAL ENERGY STORAGE WITH ZEOLITE FOR HEATING AND COOLING APPLICATIONS  

Microsoft Academic Search

Open adsorption heat pumps can be used as thermochemical heat storage systems (Wijsman, A.T.Th., Os- terhoven, R. and den Ouden,C. , 1979),( Sizmann, R.., 1987) . Such systems are interesting because of their high achievable storage capacity and coefficient of performance. They are able to provide heating as well as air conditioning. Open sorption systems can utilize the heat of

A. Hauer

61

High temperature active heat exchanger research for latent heat storage  

NASA Astrophysics Data System (ADS)

An active heat exchange method in a latent heat (salt) thermal energy storage system that prevents a low conductivity solid salt layer from forming on heat transfer surfaces was developed. An evaluation of suitable media with melting points in the temperature range of interest (250 to 400 C) limited the candidates to molten salts from the chloride, hydroxide and nitrate families, based on high storage capacity, good corrosion characteristics and availability in large quantities at reasonable cost. The specific salt recommended for laboratory tests was a choride eutectic (20.5KCL o 24.5NaCL o 55.MgCl2% by wt.), with a nominal melting point of 385 C. Various active heat exchange concepts were given a technical and economic comparison to a passive tube shell design for a reference application (300 MW sub t for 6 hours). Test hardware was then built for the most promising concept: a direct contact heat exchanger in which molten salt droplets are injected into a cooler counter flowing stream of liquid metal carrier fluid (lead/Bismuth).

Alario, J.; Haslett, R.

1982-02-01

62

Energetic performance analysis of a ground-source heat pump system with latent heat storage for a greenhouse heating  

Microsoft Academic Search

In this study, a ground-source heat pump heating system with a latent heat thermal storage tank was designed while its thermal energy storage performance was investigated. The heating system mainly consists of a ground heat exchanger, a heat pump, a cylindrical latent heat thermal storage tank, measuring units and a heating space of model-sized glass greenhouses with 30m2, located in

Hüseyin Benli

2011-01-01

63

Heat storage to cut towers' demand costs  

SciTech Connect

A thermal-storage system that will permit a Dallas office building (twin towers) to run its chiller at night during off-peak hours will lower electricity-demand charges $495,000 per year. A $411,000 utility credit will cut equipment costs to $340,000, an incentive the utility feels will help to reduce peak-demand load and delay the need for new generating capacity. Three storage tanks holding up to a total of 1.5 million gallons of water will be retrofitted into the office towers. One tank will hold hot water in the winter for morning space heating, but chilling is required on a year-round basis. (DCK)

Raymond, M.

1983-01-24

64

Charging and discharging of latent heat storage systems  

Microsoft Academic Search

The basic thermodynamic and physicochemical conditions of latent heat storage systems are discussed and some storage materials and their specific data are presented. Subcooling can be a major problem in their application and can be reduced by adding nucleating agents. A good insulation of the storage unit and a suitable heat transport system are essential for efficient operation. These topics

J. Lammers

1976-01-01

65

Cooperative Heat Transfer and Ground Coupled Storage System.  

National Technical Information Service (NTIS)

A cooperative heat transfer and ground coupled storage system wherein collected solar heat energy is ground stored and permitted to radiate into the adjacent ground for storage therein over an extended period of time when such heat energy is seasonally ma...

P. D. Metz

1979-01-01

66

Information storage medium and method of recording and retrieving information thereon  

DOEpatents

Information storage medium comprising a semiconductor doped with first and second impurities or dopants. Preferably, one of the impurities is introduced by ion implantation. Conductive electrodes are photolithographically formed on the surface of the medium. Information is recorded on the medium by selectively applying a focused laser beam to discrete regions of the medium surface so as to anneal discrete regions of the medium containing lattice defects introduced by the ion-implanted impurity. Information is retrieved from the storage medium by applying a focused laser beam to annealed and non-annealed regions so as to produce a photovoltaic signal at each region.

Marchant, D. D. (Richland, WA); Begej, Stefan (Amherst, MA)

1986-01-01

67

A heat pump system with a latent heat storage utilizing seawater installed in an aquarium  

Microsoft Academic Search

This paper introduces a heat pump system with a latent heat storage utilizing seawater installed in an aquarium. Heat from the seawater is collected and used as the heat source for the heat pump system. This maintains the indoor conditions at constant temperature and relative humidity. With regard to the heat pump system using low-temperature unutilized heat source, development is

Satoru Okamoto

2006-01-01

68

Heat storage in alloy transformations. Final report  

SciTech Connect

A study conducted to determine the feasibility of using metal alloys as thermal energy storage media is described. The study had the following major elements: (1) the identification of congruently transforming alloys and thermochemical property measurements, (2) the development of a precise and convenient method for measuring volume change during phase transformation and thermal expansion coefficients, (3) the development of a numerical modeling routine for calculating heat flow in cylindrical heat exchangers containing phase-change materials, and (4) the identification of materials that could be used to contain the metal alloys. The elements selected as candidate media were limited to aluminum, copper, magnesium, silicon, zinc, calcium, and phosphorus on the basis of low cost and latent heat of transformation. Several new eutectic alloys and ternary intermetallic phases have been determined. A new method employing x-ray absorption techniques was developed to determine the coefficients of thermal expansion of both the solid and liquid phases and the volume change during phase transformation from data that are obtained during one continuous experimental test. The method and apparatus are discussed and the experimental results are presented. The development of the numerical modeling method is presented and results are discussed for both salt and metal alloy phase-change media. Candidate materials were evaluated to determine suitable materials for containment of the metal alloys. Graphite was used to contain the alloys during the volume change measurements. Silicon carbide has been identified as a promising containment material and surface-coated iron alloys were considered.

Birchenall, C E; Gueceri, S I; Farkas, D; Labdon, M B; Nagaswami, N; Pregger, B

1981-03-01

69

THERMOCHEMICAL HEAT STORAGE FOR CONCENTRATED SOLAR POWER  

SciTech Connect

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

PROJECT STAFF

2011-10-31

70

Utility-controlled customer-side thermal-energy-storage tests: Heat storage  

NASA Astrophysics Data System (ADS)

Customer side thermal energy storage was identified as a load management option available to the electric utility industry. Five heat storage tests are described to: collect reliable load research data; delineate and solve installation problems; establish maintainability; determine customer and utility acceptance; and generate cost data to determine the potential of utility controlled customer side storage as a load management option. The utilities tested four types of heat storage systems: central ceramic brick concrete slab heat pump with storage and pressurized hot water storage. Installation and operation the storage systems indicates that the residential heat storage systems are not fully commercial in their present state for use as a load management option and the technology requires further development.

Rizy, D. T.

1982-02-01

71

Active Heat Exchange System Development for Latent Heat Thermal Energy Storage.  

National Technical Information Service (NTIS)

The results of Contract DEN 3-38, Active Heat Exchanger System Development for Latent Heat Thermal Energy Storage Systems are documented. The overall project consisted of five tasks to select, design, fabricate, test and evaluate candidate active heat exc...

R. T. LeFrois A. K. Mathur

1980-01-01

72

Primary energy savings through thermal storage in district heating networks  

Microsoft Academic Search

District heating is an efficient way to provide heat to residential, tertiary and industrial users. Heat is often produced by CHP (combined heat and power) plants, usually designed to provide the base thermal load (40–50% of the maximum load) while the rest is provided by boilers. The use of storage tanks would permit to increase the annual operating hours of

Vittorio Verda; Francesco Colella

2011-01-01

73

Heat Transfer Design Calculations for Individual Sealed Storage Casks.  

National Technical Information Service (NTIS)

Heat transfer analyses were performed for sealed casks used for the storage of high-level wastes from nuclear power plants. Three kinds of heat transfer calculations were made for individual sealed storage cask units: steady-state analyses during normal o...

H. C. Burkholder

1975-01-01

74

Phase Change Energy Storage for Solar Heating Systems  

Microsoft Academic Search

In this study, the cylindrical phase change energy storage tank linked to the water source heat pump system is investigated theoretically and experimentally. A simulation model defining the transient behavior of the phase change unit was used. In the solar energy storage tank, the phase change material (PCM) is inside cylindrical plastic tubes and heat transfer fluid (water) flows parallel

KAM?L KAYGUSUZ

2003-01-01

75

Thermoeconomic analysis of sensible heat, thermal energy storage systems  

Microsoft Academic Search

The paper considers the advantages of employing a thermoeconomic analysis for describing the complete charging–discharging cycle of sensible heat, thermal energy storage systems. The main task is to find the performance of the storage systems at the minimum total cost of owning, maintaining, and operating such systems. The effect of different monetary values on optimum number of heat transfer units,

Roman Doma?ski; Giuma Fellah

1998-01-01

76

Utilization of Basalt Stone as a Sensible Heat Storage Material  

Microsoft Academic Search

Thermal energy storage plays an important role in the conservation of thermal energy in many processes, such as waste heat recovery and load leveling at power plants, including those utilizing alternative energy sources. The objective of this study is to investigate many aspects of basalt stone as a material of heat storage. Belonging to gabbro volcanic group, magmatic basalt rock

Huseyin Gunerhan; Arif Hepbasli

2005-01-01

77

Heat-of-Adsorption Solar Thermal Energy Storage  

Microsoft Academic Search

The storage of solar thermal energy has been a subject of extensive study for many years. Various storage concepts have been extensively investigated. However, little research has been done on energy storage in the heat-of- adsorption of chemical compounds. Zeolite is, perhaps, the only substance that has been studied for its heat-of- adsorption properties (1).A recent proposal utilizes the hygroscopic

Manas Ucar; Bruce Pounder

1982-01-01

78

Thermochemical heat storage: state-of-the-art report  

SciTech Connect

This report comprises the results of the chemical heat storage (TCHS) survey and assessment study assigned to Battelle-Institut e.V., Frankfurt, by the Swedish Council for Building Research (BFR) and the Swedish Board for Technical Development (STU). In accordance with the function of BFR and STU within the Energy R and D Program of the Swedish government, emphasis is given to energy use in buildings, but aspects of the industrial application of thermochemical heat storage are included as well. Technically, this study is restricted to TCHS systems of the type heat in yields thermochemical reaction yields heat out and excludes hydrogen technology, electrochemical and photochemical methods. Various applications are considered, covering the most important sectors of energy consumption in Sweden. The TCHS systems to be studied in this context are discontinuous sorption heat pump, chemical heat storage, chemical heat pipe, and continuous sorption heat pump.

Oelert, G.; Behret, H.; Friedel, W.; Hennemann, B.; Hodgett, D.

1982-01-01

79

Chemical heat pump and chemical energy storage system  

DOEpatents

A chemical heat pump and storage system employs sulfuric acid and water. In one form, the system includes a generator and condenser, an evaporator and absorber, aqueous acid solution storage and water storage. During a charging cycle, heat is provided to the generator from a heat source to concentrate the acid solution while heat is removed from the condenser to condense the water vapor produced in the generator. Water is then stored in the storage tank. Heat is thus stored in the form of chemical energy in the concentrated acid. The heat removed from the water vapor can be supplied to a heat load of proper temperature or can be rejected. During a discharge cycle, water in the evaporator is supplied with heat to generate water vapor, which is transmitted to the absorber where it is condensed and absorbed into the concentrated acid. Both heats of dilution and condensation of water are removed from the thus diluted acid. During the discharge cycle the system functions as a heat pump in which heat is added to the system at a low temperature and removed from the system at a high temperature. The diluted acid is stored in an acid storage tank or is routed directly to the generator for reconcentration. The generator, condenser, evaporator, and absorber all are operated under pressure conditions specified by the desired temperature levels for a given application. The storage tanks, however, can be maintained at or near ambient pressure conditions. In another form, the heat pump system is employed to provide usable heat from waste process heat by upgrading the temperature of the waste heat.

Clark, Edward C. (Woodinville, WA); Huxtable, Douglas D. (Bothell, WA)

1985-08-06

80

Low temperature heat storage with phase change materials  

NASA Astrophysics Data System (ADS)

A group of promising phase-change heat-storage materials was selected through study of the literature, laboratory tests of freeze-melt behavior and determination of thermophysical properties. Means were developed for encapsulating these materials in metal or plastic containers. Four of these phase-change materials, suitably encapsulated, were tested in a sub-scale thermal storage unit of about 20 MJ capacity, using air as the heat-transfer fluid. In most cases, measured thermal-storage capacity exceeded 90% of the theoretical value. After consideration of a number of heating and cooling schemes employing phase-change heat storage, a forced hot air, central storage design, using CaCl2.6H2O encapsulated in plastic pipes was selected. A home was designed, using a two-story conservatory for solar collection with vertical glazing and movable insulation.

Lane, G. A.

1980-07-01

81

Experimental studies on the behaviours of hydride heat storage system  

Microsoft Academic Search

Experimental examinations and a lumped system model are used to describe the heat transfer characteristics in the design of a single tube type metal hydride heat storage vessel. The apparatus studied was fed heat by water vaporized by an electric furnance with a 3 kWh x 2 capacity. An annular tube in the middle of the reactor vessel contained the

M. Kawamura; S. Ono; S. Higano

1982-01-01

82

SORBTION MATERIALS FOR APPLICATION IN SOLAR HEAT ENERGY STORAGE  

Microsoft Academic Search

Solar energy can be used in seasonal heating systems. The high amount of energy available in summer time is stored in water storage tanks for use in wintertime. In the case of well-insulated one family houses, with a yearly heat demand for domestic hot water and space heating of about 5000 kWh, water tanks with a volume in the range

P. Gantenbein; S. Brunold; F. Flückiger; U. Frei

83

Design and simulation of latent heat storage units  

SciTech Connect

This report presents the results of two years of research and development on passive latent heat storage systems. Analytical models have been developed and extended, and a computer code for simulating the performance of a latent heat storage has been developed. The code is intended to be merged into a larger solar energy system simulation code and used for making realistic system studies. Simulation studies using a code which has a flexible and accurate routine for handling the storage subsystem should lead to the development of better systems than those in which storage is added on after the rest of the system has already been selected and optimized.

Shamsundar, N.; Stein, E.; Rooz, E.; Bascaran, E.; Lee, T.C. (Houston Univ., TX (United States))

1992-04-01

84

Design and simulation of latent heat storage units. Final report  

SciTech Connect

This report presents the results of two years of research and development on passive latent heat storage systems. Analytical models have been developed and extended, and a computer code for simulating the performance of a latent heat storage has been developed. The code is intended to be merged into a larger solar energy system simulation code and used for making realistic system studies. Simulation studies using a code which has a flexible and accurate routine for handling the storage subsystem should lead to the development of better systems than those in which storage is added on after the rest of the system has already been selected and optimized.

Shamsundar, N.; Stein, E.; Rooz, E.; Bascaran, E.; Lee, T.C. [Houston Univ., TX (United States)

1992-04-01

85

Molten Glass for Thermal Storage: Advanced Molten Glass for Heat Transfer and Thermal Energy Storage  

SciTech Connect

HEATS Project: Halotechnics is developing a high-temperature thermal energy storage system using a new thermal-storage and heat-transfer material: earth-abundant and low-melting-point molten glass. Heat storage materials are critical to the energy storage process. In solar thermal storage systems, heat can be stored in these materials during the day and released at night—when the sun is not out—to drive a turbine and produce electricity. In nuclear storage systems, heat can be stored in these materials at night and released to produce electricity during daytime peak-demand hours. Halotechnics new thermal storage material targets a price that is potentially cheaper than the molten salt used in most commercial solar thermal storage systems today. It is also extremely stable at temperatures up to 1200°C—hundreds of degrees hotter than the highest temperature molten salt can handle. Being able to function at high temperatures will significantly increase the efficiency of turning heat into electricity. Halotechnics is developing a scalable system to pump, heat, store, and discharge the molten glass. The company is leveraging technology used in the modern glass industry, which has decades of experience handling molten glass.

None

2012-01-01

86

Intermediate temperature, heat storage and retrieval system  

Microsoft Academic Search

Energy is stored by heating a salt to a temperature above its latent heat of fusion to convert the salt to a liquid state. Heat is retrieved by moving a heat transfer fluid that is immiscible with the salt and has a density less than that of the salt over the top surface of the liquid salt at such a

Greene

1980-01-01

87

Investigation of nitrate salts for solar latent heat storage  

Microsoft Academic Search

The properties of heat transfer in the discharging of a model solar latent heat storage unit based on various nitrate salts and salt mixtures are investigated. A shell-and-tube-type passive heat exchanger containing NaNO3 or eutectic or off-eutectic mixtures of NaNO3 with KNO3 and Ca(NO3)2 was heated to 40 K above the melting temperature of the salt, when air was made

M. Kamimoto; T. Tanaka; T. Tani; T. Horigome

1980-01-01

88

Graphene oxide stabilized polyethylene glycol for heat storage.  

PubMed

Graphene oxide (GO) sheets were introduced to stabilize the melted polyethylene glycol (PEG) during the solid-liquid phase change process, which can be used as a smart heat storage system. The structural properties and phase change behaviors of the PEG-GO composites were comprehensively investigated as a function of the PEG content by means of various characterization techniques. The highest stabilized PEG content is 90 wt% in the composites, resulting in a heat storage capacity of 156.9 J g(-1), 93.9% of the phase change enthalpy of pure PEG. Notably, GO has much stronger impact on lowering of the phase change temperature of PEG compared with some other porous carbon materials (activated carbon and ordered mesoporous carbon) due to the unique thin layer structure of GO. Because of the high heat storage capacity and the moderate phase change temperature, the PEG-GO composite is a promising heat energy storage candidate at mild temperature. PMID:22914763

Wang, Chongyun; Feng, Lili; Yang, Huazhe; Xin, Gongbiao; Li, Wei; Zheng, Jie; Tian, Wenhuai; Li, Xingguo

2012-10-14

89

Heat storage in forest biomass improves energy balance closure  

NASA Astrophysics Data System (ADS)

Temperature measurements in trunks and branches in a mature ca. 100 years-old mixed pine and spruce forest in central Sweden were used to estimate the heat storage in the tree biomass. The estimated heat flux in the sample trees and data on biomass distributions were used to scale up to stand level biomass heat fluxes. The rate of change of sensible and latent heat storage in the air layer below the level of the flux measurements was estimated from air temperature and humidity profile measurements and soil heat flux was estimated from heat flux plates and soil temperature measurements. The fluxes of sensible and latent heat from the forest were measured with an eddy covariance system in a tower. The analysis was made for a two-month period in summer of 1995. The tree biomass heat flux was the largest of the estimated storage components and varied between 40 and -35 W m-2 on summer days with nice weather. Averaged over two months the diurnal maximum of total heat storage was 45 W m-2 and the minimum was -35 W m-2. The soil heat flux and the sensible heat storage in air were out of phase with the biomass flux and they reached maximum values that were about 75% of the maximum of the tree biomass heat storage. The energy balance closure improved significantly when the total heat storage was added to the turbulent fluxes. The slope of a regression line with sum of fluxes and storage as independent and net radiation as dependent variable, increased from 0.86 to 0.95 for half-hourly data and the scatter was also reduced. The most significant finding was, however, that during nights with strongly stable conditions when the sensible heat flux dropped to nearly zero, the total storage matched the net radiation very well. Another interesting result was that the mean energy imbalance started to increase when the Richardson number became more negative than ca. -0.1. In fact, the largest energy deficit occurred at maximum instability. Our conclusion is that eddy covariance measurements can function well during stable conditions but that the functioning under strong instabilities might be a so far unforeseen problem.

Lindroth, A.; Mölder, M.; Lagergren, F.

2010-01-01

90

Intermediate temperature, heat storage and retrieval system  

SciTech Connect

Energy is stored by heating a salt to a temperature above its latent heat of fusion to convert the salt to a liquid state. Heat is retrieved by moving a heat transfer fluid that is immiscible with the salt and has a density less than that of the salt over the top surface of the liquid salt at such a velocity that the upper layer of the salt is emulsified with the heat transfer fluid to crystallize the salt in the upper layer. Heat is thereby exothermally surrendered to the heat transfer fluid and the crystallized salt gravitates from said top surface, thereby maintaining the top surface in a liquid state. It is preferred to move the heat transfer fluid over the top surface of the salt in either a vortex pattern, or an outward radial pattern. The heat transfer liquid is a liquid selected from the group consisting essentially of therminol, caloria santowax, and di-butyl phthalate.

Greene, N.D.

1980-10-14

91

Review on sustainable thermal energy storage technologies, Part I: heat storage materials and techniques  

Microsoft Academic Search

This paper reviews the development of available thermal energy storage (TES) technologies and their individual pros and cons for space and water heating applications. Traditionally, available heat has been stored in the form of sensible heat (typically by raising the temperature of water, rocks, etc.) for later use. In most of the low temperature applications, water is being used as

S. M. Hasnain

1998-01-01

92

Culture medium pH is influenced by basal medium, carbohydrate source, gelling agent, activated charcoal, and medium storage method  

Microsoft Academic Search

When four carbohydrates were tested against six commonly cited inorganic basal media, post-autoclave pH was highest for carbohydrate-free and sucrose containing media, and progressively lower for maltoseglucose and fructose-containing media, respectively. Post-autoclave pH for these media without carbohydrates was related to medium buffering capacity. Addition of gelling agents (10 of 11 tested) increased the postautoclave pH of MS medium containing

Henry R. Owen; Donna Wengerd; A. Raymond Miller

1991-01-01

93

A STUDY ON THE SOLIDIFICATION HEAT TRANSFER CHARACTERISTICS OF HEAT STORAGE SYSTEM UTILIZING THE PCM  

Microsoft Academic Search

This study is concerned with the solidification heat transfer characteristics of phase change energy storage system. The heat transfer characteristics experiment for the solidification of PCM is performed on the PCM cylindrical heat exchanger with six fins. Experimental results are compared with the theory to investigate the appropriateness of heat conduction equation of PCM and the effect of coolant inlet

WOO SIK KIM; HEE OEUL SONG

1988-01-01

94

Heat storage capability of a rolling cylinder using Glauber's salt  

NASA Astrophysics Data System (ADS)

The thermal properties of a rolling cylindrical phase-change heat storage device using Glauber's salt, sodium sulfate decahydrate, are investigated calorimetrically. Horizontal cylinders made of FERNICO alloy and stainless steel were filled with Glauber's salt and rotated about their axes within a calorimeter to measure the heat given off and absorbed by the cylinder during the freezing and melting of the salt at 90.3 F. Results reveal complete phase changes during operation, with a latent heat release up to 100% of theoretical and repeatable performance over 150 melting-freezing cycles. High heat release rates, internal heat transfer rates and heat exchanger surface temperatures are also observed, and freezing is found to occur uniformly. It is concluded that the rolling cylinder is a potential high-performance heat storage device, with no technical barriers to its further development.

Herrick, C. S.; Zarnoch, K. P.

1980-01-01

95

Heating of the Diffuse Interstellar Medium via Turbulent Wave Dissipation  

NASA Astrophysics Data System (ADS)

We consider the heating of the interstellar medium (ISM) due to obliquely propagating fast magnetosonic waves which have been postulated to comprise a portion of the observed turbulence in the ISM. Recent papers have reported measurements of the outer scale of the turbulence in the ISM and the strength of the turbulent magnetic field (Minter and Spangler 1996 ApJ, in press), the inner scale of the turbulence (Molnar et al. 1995 ApJ, 438, 708) and the plasma density in the scattering regions from H_? measurements (Reynolds 1991, ApJ Letters, 372, L21). We can now completely specify the characteristics of the turbulence in the diffuse ISM. These new measurements allow us to apply theoretical expressions for the heating rates for various magnetohydrodynamical wave damping mechanisms presented by Spangler (1991, ApJ, 376, 540). These calculates show that heating of the ISM by wave damping would exceed its radiative cooling capability. We are therefore able to rule out the possibility that the turbulence in the diffuse ISM is composed entirely of obliquely propagating fast magnetosonic waves

Minter, A.; Spangler, S.

1995-12-01

96

Enhancement of Heat Transfer in Latent Heat Storage Modules with Internal Fins  

Microsoft Academic Search

The main objective of this study is to investigate the enhancement of energy storage rate of a thermal energy storage unit filled with a phase change material (PCM) by inserting a fin array system into the storage device. Heat is transferred to the unit through the container walls, to which aluminum fins are attached. The PCM, a commercial paraffin wax,

Maryam Gharebaghi; I. Sezai

2008-01-01

97

Cu-Si bilayers as storage medium in optical recording  

SciTech Connect

Instead of a phase change or a dye layer, a Cu/Si bilayer can be applied as the recording medium in a write-once Blu-ray Disc. The write process basically comprises the formation of a CuSi alloy containing 25-30 at. % Si, while any excess of Si is left behind as unreacted film. Auger analyses of the laser-written layers indicate that recording consists primarily of the diffusion of Si into Cu. The data allow for discrimination between the various models presented in literature for Cu/Si-based recording and to optimize the stack. Very low jitter levels of typically 4% proved to be achievable with equally thick films of Cu and Si as recording medium.

Kuiper, A.E. T.; Vullers, R.J.M.; Pasquariello, D.; Naburgh, E.P. [Philips Research Laboratories, Prof. Holstlaan 4, 5656 AA Eindhoven (Netherlands)

2005-05-30

98

Active heat exchange system development for latent heat thermal energy storage  

Microsoft Academic Search

The selection and evaluation phase of a program to develop active heat exchange concepts for latent heat thermal energy storage systems applicable to the utility industry is described. An evaluation of suitable storage media with melting points in the temperature range of interest (250 to 400°C) limited the candidates to molten salts from the chloride, hydroxide and nitrate families, based

J. Alario; R. Kosson; R. Haslett

1980-01-01

99

Numerical simulation of a latent heat thermal energy storage system with enhanced heat conduction  

Microsoft Academic Search

A latent heat storage system has been designed to take advantage of the off-peak electrical energy for space heating. Using an enthalpy formation and a fully implicit finite difference method, the thermal performance of such a storage system with and without fins has been analysed. For the one-dimensional simulation model, calculations have been made for the melt fraction and energy

M. Costa; D. Buddhi; A. Oliva

1998-01-01

100

Heat storage to cut towers' demand costs  

Microsoft Academic Search

A thermal-storage system that will permit a Dallas office building (twin towers) to run its chiller at night during off-peak hours will lower electricity-demand charges $495,000 per year. A $411,000 utility credit will cut equipment costs to $340,000, an incentive the utility feels will help to reduce peak-demand load and delay the need for new generating capacity. Three storage tanks

1983-01-01

101

Effect of heat treatment, water activity and storage temperature on the oxidative stability of whole milk powder  

Microsoft Academic Search

The oxidative status of high-heat, medium-heat and low-heat whole milk powder was investigated at moderately accelerated storage conditions, with exposure to atmospheric air at 25 or 45 °C and at three water activities (0.11, 0.23 and 0.33 at 25 °C, and 0.11, 0.17 and 0.31 at 45 °C) for 2 months using: (i) electron spin resonance spectrometry for measurement of

Henrik Stapelfeldt; Bo R. Nielsen; Leif H. Skibsted

1997-01-01

102

Heat treatment for disinfestation of empty grain storage bins  

Technology Transfer Automated Retrieval System (TEKTRAN)

An alternative to fumigants and insecticides for controlling stored-product insects in empty grain storage bins prior to filling is heat treatment in which the temperature is quickly raised to a minimum of 50°C and held there for two to four hours. Effectiveness of heat treatments on empty grain sto...

103

Latent heat thermal energy storage for lunar oxygen production  

SciTech Connect

A necessary component of a solar-based lunar oxygen production system is a thermal energy storage module. We discuss some of the heat transfer and phase change problems associated with the design and operation of such a module based on the latent heat of melting of lunar rock. 12 refs.

Solomon, A.D. [Solomon (A.D.), Omer (Israel); Alexiades, V.; Jacobs, G.; Naney, M.; Olszewski, M. [Oak Ridge National Lab., TN (United States)

1992-08-01

104

Latent heat thermal energy storage for lunar oxygen production  

SciTech Connect

A necessary component of a solar-based lunar oxygen production system is a thermal energy storage module. We discuss some of the heat transfer and phase change problems associated with the design and operation of such a module based on the latent heat of melting of lunar rock. 12 refs.

Solomon, A.D. (Solomon (A.D.), Omer (Israel)); Alexiades, V.; Jacobs, G.; Naney, M.; Olszewski, M. (Oak Ridge National Lab., TN (United States))

1992-01-01

105

Thermal conductivity enhancement in a latent heat storage system  

Microsoft Academic Search

Latent heat storage systems especially those employing organic materials have been reported to exhibit a rather slow thermal response. This is mainly due to the relatively low thermal conductivity of organic latent heat materials. In this study, experiments were carried out to investigate a method of enhancing the thermal conductivity of paraffin wax by embedding aluminum powder in it. The

Eman-Bellah S. Mettawee; Ghazy M. R. Assassa

2007-01-01

106

Analysis of thermally degraded sensible heat storage hydrocarbons  

Microsoft Academic Search

Heat treated samples of three candidate fluids for sensible heat storage were analyzed using gel-permeation chromatography and infrared spectrophotometry. Comparison of this data with previous work reveals that: The oil is undergoing large-scale thermal cracking that is probably catalyzed by the presence of degradation products. The oil is possibly experiencing some amount of dehydrogenation. There is a very small amount

Burolla

1977-01-01

107

A&M. Radioactive parts security storage area, heat removal storage casks. ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

A&M. Radioactive parts security storage area, heat removal storage casks. Plan, section, and details. Ralph M. Parsons 1480-7 ANP/GE-3-720-S-1. Date: November 1958. Approved by INEEL Classification Office for public release. INEEL index no. 034-0720-60-693-107459 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

108

Lightweight thermal storage for solar heated buildings  

Microsoft Academic Search

A new building element is introduced that greatly improves the thermal and architectural performance of passively heated structures. Insolated ceiling tiles charged with thin layers of phase change material are used to stabilize room temperatures and store large quantities of heat without using weighty materials which are expensive to support in multiple story structures. Experimental and analytical results are presented

T. E. Johnson

1977-01-01

109

Aquifer thermal energy (heat and chill) storage  

SciTech Connect

As part of the 1992 Intersociety Conversion Engineering Conference, held in San Diego, California, August 3--7, 1992, the Seasonal Thermal Energy Storage Program coordinated five sessions dealing specifically with aquifer thermal energy storage technologies (ATES). Researchers from Sweden, The Netherlands, Germany, Switzerland, Denmark, Canada, and the United States presented papers on a variety of ATES related topics. With special permission from the Society of Automotive Engineers, host society for the 1992 IECEC, these papers are being republished here as a standalone summary of ATES technology status. Individual papers are indexed separately.

Jenne, E.A. (ed.)

1992-11-01

110

Aquifer thermal energy (heat and chill) storage  

NASA Astrophysics Data System (ADS)

As part of the 1992 Intersociety Conversion Engineering Conference (IECEC), held in San Diego, California, 3 - 7 Aug. 1992, the Seasonal Thermal Energy Storage Program coordinated five sessions dealing specifically with aquifer thermal energy storage technologies (ATES). Researchers from Sweden, The Netherlands, Germany, Switzerland, Denmark, Canada, and the United States presented papers on a variety of ATES related topics. With special permission from the Society of Automotive Engineers, host society for the 1992 IECEC, these papers are being republished here as a standalone summary of ATES technology status. Individual papers are indexed separately.

Jenne, E. A.

1992-11-01

111

Experimental Research of Sleeping Bed Integrated with PCM Heat Storage and Solar Heating  

Microsoft Academic Search

This paper puts forward a new way of using solar energy and Phase Change Material (PCM): the integration of PCM, sleeping bed and solar energy. The cavity of sleeping bed is filled with PCM. The sleeping bed is a heat storage device charged by solar energy, and it is a heating terminal too. The performance of heat charging and discharging

Guoqing Yu; Ji Qiang; Huizhong Zhao; Zonghu Lv

2009-01-01

112

Analysis and summary of a solar air collector-groundwater heat storage-greenhouse heating system  

Microsoft Academic Search

An air-type solar energy collector with reflective wings at the top and bottom was developed and adapted to heat a soil and groundwater heat storage from which energy was reclaimed to heat a greenhouse. Collector efficiency correlation for summer and winter months are presented for seasonal collector tilts of 30° and 60°, respectively. The collector performance data and correlations show

A. C. Dale; V. M. Puri; J. R. Barrett; P. A. Hammer

1981-01-01

113

Heat Transfer Analysis of a Packed Bed-PCM Capsules Latent Heat Thermal Energy Storage System  

Microsoft Academic Search

Heat transfer analysis of a packed bed-PCM latent heat thermal energy storage system is presented in this study. The packed bed cylindrical column is filled with spherical capsules of PCM (paraffin wax) that is used for a solar water heating application. In this study, the physical model is developed to use for analyzing the thermal performance of packed bed-PCM latent

Z. S. Abdel-Rehim

2011-01-01

114

Conversion of medium and low temperature heat to power  

NASA Astrophysics Data System (ADS)

Presently most electricity is produced in power plants which use high temperature heat supplied by coal, oil, gas or nuclear fission and Clausius-Rankine cycles (CRC) with water as working fluid (WF). On the other hand, geo-, solar-, ocean-, and biogenic-heat have medium and low temperatures. At these temperatures, however, the use of other WF and/or other cycles can yield higher efficiencies than those of the water-CRC. For an assessment of the efficiency we model systems which include the heat transfer to and from the WF and the cycle. Optimization criterion is the exergy efficiency defined as the ratio of the net power output to the incoming exergy flow of the heat carrier. First, for a better understanding we discuss some thermodynamic properties of the WFs: 1) the critical point parameters, 2) the shape of the vapour- liquid coexistence curve in the temperature vs entropy (T,s)-diagram which may be either bell-shaped or overhanging [1,2], and 3) the shape of sub- and supercritical isobars for pure fluids and fluid mixtures. Second, we show that the problems of a CRC with water at lower temperatures are 1) the shape of the T,s-diagram and 2) the exergy loss during heat transfer to the WF. The first problem can be overcome by using an organic working fluid in the CRC which then is called organic Rankine cycle (ORC). The second problem is reduced by supercritical organic Rankine cycles (sORC) [1,2], trilateral cycles (TLC) and the more general power-flash cycles (PFC) [2], and organic flash cycles (OFC) [3]. Next, selected results for systems with the above mentioned cycles will be presented. The heat carrier inlet temperatures THC range from 120°C to 350°C.The pure working fluids are water, refrigerants, alkanes, aromates and siloxanes and have to be selected to match with THC. It is found that TLC with water have the highest efficiencies but show very large volume flows at lower temperatures. Moreover, expansion machines for TLC and PFC are still under improvement. Presently, the best feasible systems seem to be ORC cycles using WF with a nearly vertical dew line in the T,s-diagram as HFO-1234yf, n-butane or cyclopentane and upper pressures close below or above (sORC) the critical pressure. Finally, we will consider the above cycles also with mixtures as WF including the Kalina cycle and coupled processes like cascade or multistage processes. [1] B Saleh, G Koglbauer, M Wendland, J Fischer, Working fluids for low temperature ORC-processes, Energy 32, 1210-21 (2007). [2] N A Lai, J Fischer, Efficiencies of Power Flash Cycles, Energy 44, 1017-27 (2012). [3] T Ho, S S Mao, R Greif, Comparison of the Organic Flash Cycle (OFC) to other advanced vapor cycles for intermediate and high temperature waste heat reclamation and solar thermal energy, Energy 42, 213-23 (2012).

Fischer, Johann; Wendland, Martin; Lai, Ngoc Anh

2013-04-01

115

An experimental study on the heat transfer characteristics of a heat pipe heat exchanger with latent heat storage. Part II: Simultaneous charging\\/discharging modes  

Microsoft Academic Search

In this part of the paper, the performance of the simultaneous charging\\/discharging operation modes of the heat pipe heat exchanger with latent heat storage is experimentally studied. The experimental results show that the device may operate under either the fluid to fluid heat transfer with charging heat to the phase change material (PCM) or the fluid to fluid heat transfer

Zhongliang Liu; Zengyi Wang; Chongfang Ma

2006-01-01

116

Heat transfer effects in compressed air energy storage  

Microsoft Academic Search

Compressed-air energy-storage (CAES) systems are being developed for peak-load-leveling applications by electric utilities. Energy is stored by compressing air in an underground cavern; when power is required, the air is heated and expanded through a turbine-generator system. This work is part of a conceptual design of an 800-MW CAES system which uses a set of storage cavities mined in salt.

K. G. Vosburgh; P. G. Kosky

1977-01-01

117

Low temperature heat storage with phase change materials  

Microsoft Academic Search

A group of promising phase-change heat-storage materials was selected through study of the literature, laboratory tests of freeze-melt behavior and determination of thermophysical properties. Means were developed for encapsulating these materials in metal or plastic containers. Four of these phase-change materials, suitably encapsulated, were tested in a sub-scale thermal storage unit of about 20 MJ capacity, using air as the

1980-01-01

118

Cold Thermal Storage and Cryogenic Heat Engines for Energy Storage Applications  

Microsoft Academic Search

A theoretical analysis is presented of heat engines that use the atmosphere as a hot reservoir and a cryogenic medium as a cold reservoir. These “cryogenic” heat engines can be used as zero emission power sources and are found to have unexpectedly large specific work (work per unit mass of the cold reservoir) values when gases of low atomic mass

C. A. ORDONEZ; M. C. PLUMMER

1997-01-01

119

Heat loading limits for solid transuranic wastes storage  

SciTech Connect

Heat loading limits have been established for four storage configurations of TRU wastes. The calculations were performed assuming the worst case scenario whereby all the heat generated within a drum was generated within one ``cut`` and that this cut was located in the very center of the drum. Poly-boxes containing one HEPA filter were assumed to have a uniform heat generation throughout the filter. The maximum allowable temperatures were based on the materials in the containers. A comparison between the drum center temperature for a uniform heat load distribution and for the center temperature when the heat load is confined to one cut in the center of the drum is also illustrated. This comparison showed that the heat load of a particular drum can be more than doubled by distributing the sources of heat uniformly throughout the container.

Spatz, T.L.

1993-07-01

120

Thermal energy storage technologies for heating and cooling applications  

NASA Astrophysics Data System (ADS)

Recent results from selected thermal energy storage (TES) research activities in Germany and Sweden are discussed. In addition, several new technologies for heating and cooling of buildings and automobiles were reviewed and found to benefit similar efforts in the United states. Details of a meeting with Didier-Werke AG, a leading German ceramics manufacturer who will provide TES media necessary for the United States to complete field tests of an advanced high temperature latent heat storage material, are presented. Finally, an overview of the December 1990 International Energy Agency (IEA) Executive Committee deliberations on TES is presented.

Tomlinson, John J.

1990-12-01

121

Earth storage of solar heat. Final report  

SciTech Connect

The purpose of this project was to demonstrate that large quantities of heat could be collected and stored by modifing large buildings such as those commonly found on farms. The basic idea was to install a solar collection system on the south roof of such a building and store the heat collected in the earth under the building. To implement the project, a pole type sheet metal building was constructed. The size of the building was 20' x 40'. The peak of the roof ran down the 40' dimension and was offset from the center line so that the roof surface facing south was larger than that facing north. The collector was built on the south side by first constructing a roof of sheet metal with 2-1/2'' corrugations. The sheet metal was painted with flat black paint to absorb the solar heat. A space was created over the sheet metal roof by nailing 2 x 4's spaced 2' apart to it. Corrugated fiberglass sheets were nailed to these 2 x 4's to make the collector cover. At the top of the roof, a distribution pipe made of 3/4'' CVCP plastic pipe with 1/8'' holes to match the corrugations of the sheet metal was installed. A gutter was installed at the bottom to collect the heated water which flowed down the sheet metal. The collector roof and the gutter were insulated with 6'' fiberglass batts to complete the collector. Instrumentation, cost, and performance results are discussed.

Garst, P.

1982-04-19

122

Solar-assisted heat pump and energy storage for residential heating  

SciTech Connect

In order to investigate the performance of a solar-assisted heat pump system with energy storage for residential heating in the Black Sea region of Turkey, an experimental setup was constructed. This experimental apparatus consisted of flat plate solar collectors with total area of 30 m[sup 2], a laboratory building with 75 m[sup 2] floor area for heating purpose, a latent heat thermal energy storage tank filled by 1500 kg encapsulated phase change material (PCM)I, a heat pump with double evaporators (air-sourced and water-sourced) and one condenser, a water circulating pump, and measuring equipments. The experimental results were obtained December-May during the heating season of 1992 for the solar-assisted heat pump system used. The experimentally obtained results were used to calculate the collector efficiency, coefficient of performance of heat pump (COP), system COP, storage efficiency, and total energy consumption of the system during the heating season. The mean value of the collector efficiency, heat pump COP, system COP, and storage efficiency were found 70%, 4.5%, 4.0%, and 60%, respectively.

Comakli, O. (Atatuerk Univ., Erzurum (Turkey)); Kaygusuz, K.; Ayhan, T. (Karadeniz Technical Univ., Trabzon (Turkey))

1993-11-01

123

Plasmonic data storage medium with metallic nano-aperture array embedded in dielectric material.  

PubMed

We propose a plasmonic data storage medium with a high-transmission metal aperture array embedded in a dielectric material. Bowtie apertures, having an outline of 80 nm and a ridge gap of 30 nm, are arranged in a two dimensional array with a bit pitch of 100 nm and a track pitch of 280 nm. Using the finite differential time domain (FDTD) method, we calculate the exposure power needed to record optical data, the contrast for readability of recorded data, and cross talk between the main track and adjacent tracks. Compared to a conventional blu-ray disc, the exposure power needed to record optical data in the proposed plasmonic data storage medium is less than a quarter of the conventional threshold power, and the density of the data storage is about 1.8 times larger. PMID:19997244

Park, Sinjeung; Won Hahn, Jae

2009-10-26

124

Determination of body heat storage in clothing: calorimetry versus thermometry  

Microsoft Academic Search

Two methods of estimating body heat storage were compared under differing conditions of clothing, training, and acclimation to heat. Six male subjects underwent 8 weeks of physical training [60–80% of maximal aerobic power (\\u000a$$\\\\dot VO_{2\\\\max } $$\\u000a) for 30–45 min · day–, 3–4 days · week–1 at \\u000a$$\\\\dot VO_{2\\\\max } $$\\u000a for 60 min · day–1 at 40°C

Yukitoshi Aoyagi; Tom M. McLellan; Roy J. Shephard

1995-01-01

125

An experimental study on heat transfer characteristics of heat pipe heat exchanger with latent heat storage. Part I: Charging only and discharging only modes  

Microsoft Academic Search

A new thermal storage system, a heat pipe heat exchanger with latent heat storage, is reported. The new system may operate in three basic different operation modes, the charging only, the discharging only and the simultaneous charging\\/discharging modes, which makes the system suitable for various time and\\/or weather dependent energy systems. In this part of the paper, the basic structure,

Zhongliang Liu; Zengyi Wang; Chongfang Ma

2006-01-01

126

Heat transfer enhancement in water when used as PCM in thermal energy storage  

Microsoft Academic Search

Efficient and reliable storage systems for thermal energy are an important requirement in many applications where heat demand and supply or availability do not coincide. Heat and cold stores can basically be divided in two groups. In sensible heat stores the temperature of the storage material is increased significantly. Latent heat stores, on the contrary, use a storage material that

L. F. Cabeza; H. Mehling; S. Hiebler; F. Ziegler

2002-01-01

127

Efficient Heat Storage Materials: Metallic Composites Phase-Change Materials for High-Temperature Thermal Energy Storage  

SciTech Connect

HEATS Project: MIT is developing efficient heat storage materials for use in solar and nuclear power plants. Heat storage materials are critical to the energy storage process. In solar thermal storage systems, heat can be stored in these materials during the day and released at night—when the sun’s not out—to drive a turbine and produce electricity. In nuclear storage systems, heat can be stored in these materials at night and released to produce electricity during daytime peak-demand hours. MIT is designing nanostructured heat storage materials that can store a large amount of heat per unit mass and volume. To do this, MIT is using phase change materials, which absorb a large amount of latent heat to melt from solid to liquid. MIT’s heat storage materials are designed to melt at high temperatures and conduct heat well—this makes them efficient at storing and releasing heat and enhances the overall efficiency of the thermal storage and energy-generation process. MIT’s low-cost heat storage materials also have a long life cycle, which further enhances their efficiency.

None

2011-11-21

128

Heat exchangers and thermal energy storage concepts for the off-gas heat of steelmaking devices  

NASA Astrophysics Data System (ADS)

The fluctuating thermal emissions of electric arc furnaces require energy storage systems to provide downstream consumers with a continuous amount of thermal energy or electricity. Heat recovery systems based on thermal energy storage are presented. A comparison of different thermal energy storage systems has been performed. For the purpose, suitable heat exchangers for the off-gas heat have been developed. Dynamic process simulations of the heat recovery plants were necessary to check the feasibility of the systems and consider the non-steady-state off-gas emissions of the steelmaking devices. The implementation of a pilot plant into an existing off-gas duct of an electric arc furnace was required to check the real behavior of the heat exchanger and determine suitable materials in view of corrosion issues. The pilot plant is presented in this paper.

Steinparzer, T.; Haider, M.; Fleischanderl, A.; Hampel, A.; Enickl, G.; Zauner, F.

2012-11-01

129

Thermal Energy Storage System Using a Technical Grade Paraffin Wax as Latent Heat Energy Storage Material  

Microsoft Academic Search

The objective of this study was to experimentally establish thermal energy storage (TES) performance using a technical grade paraffin wax as a phase change material (PCM) in a vertical concentric pipe-in-pipe latent heat storage system. The melting and solidification temperature range of the paraffin was found as 38°C–43°C and 36°C–42°C, respectively. These values were well in agreement with the values

Kamil Kaygusuz; Ahmet Sari

2005-01-01

130

Mathematical description of a boiler house operating jointly with a wind power plant and heat storage  

NASA Astrophysics Data System (ADS)

A heat supply system is considered that contains, along with a boiler house, a wind power plant and heat storage. Methodical approaches for determining the operating modes of the heat storage jointly with the wind power plant are developed. A mathematical model of the heat storage is obtained using which a numerical experiment can be carried out. Results determining the positive energy effect from using a system combining a wind power plant and heat storage are presented.

Bezhan, A. V.; Minin, V. A.

2011-11-01

131

Studies of a Salt Hydrate Heat Storage System.  

National Technical Information Service (NTIS)

Crystallization of a one and two component system for thermal storage by fusion heat of salt hydrates has been investigated for sodium sulfate (10H2O); sodium thiosulfate (5H2O) and sodium acetate (3H2O). A continuous input of small crystals which grew an...

L. Christensen N. Cho G. Keyser D. Lamb E. Wedum

1978-01-01

132

District Heating and Seasonal Storage in Confined Aquifer at Plaisir.  

National Technical Information Service (NTIS)

A system for big sized storage of heat between seasons has been studied for more than 10 years by a french petroleum group - the ELF-AQUITAINE National Cy - and the Atomic Energy Commissariat, with the financial assistance of the Agence Francaise pour la ...

J. Despois

1987-01-01

133

An improved PCM heat storage technology utilizing metal foam  

Microsoft Academic Search

Having a uniform temperature for electronics is part of thermal management in order to avoid hot spots and reduce thermal stresses in electronic systems. In many applications, thermal energy storage is required to receive, store, and subsequently release heat. The major disadvantage of phase change materials (PCMs) is their low thermal conductivities, which drastically slows the phase change process and

Nihad Dukhan; Sujay Bodke

2010-01-01

134

Application of CESE method to simulate non-Fourier heat conduction in finite medium with pulse surface heating  

Microsoft Academic Search

This study employs the space–time conservation element and solution element (CESE) method to simulate the temperature and heat flux distributions in a finite medium subject to various non-Fourier heat conduction models. The simulations consider three specific cases, namely a single phase lag (SPL) thermal wave model with a pulsed temperature condition, a SPL model with a surface heat flux input,

Yin Chou; Ruey-Jen Yang

2008-01-01

135

Performance comparison of domestic solar heating system using saturated ground soil storage as an alternative to water, rocks, and Glauber's salt  

SciTech Connect

A three dimension, finite difference, unsteady-state heat transfer model has been developed to simulate heat transfer to and from air passing through pipes buried in sealed, water saturated ground soil. This was used to study the heat transfer characteristics of ground soil as a heat storage medium. In addition, heat storage simulation models for rocks, water and Glauber's salt proposed by other researchers have been used to compare their heat transfer performance with saturated ground soil. Furthermore, life cycle cost comparisons of domestic solar systems with different types of storage materials, namely, water, rocks, Glauber's salt, and saturated ground soil, are included. Total heat capacity of the storage unit is considered a parameter in this study. Cost analysis indicates that saturated ground soil is more expensive than water, but cheaper than rocks and Glauber's salt.

Puri, V.M.; Okos, M.R.

1980-01-01

136

Status seminar '98: Solar-supported district heating with seasonal heat storage. Status report '98.  

National Technical Information Service (NTIS)

This status report refers to the BMBF (Federal Ministry for Education, Science, Research and Technology) status seminar: Solar-assisted district heat supply - seasonal heat storage that took place in Neckarsulm on 19th and 20th May. 1998. The report conta...

1998-01-01

137

Heat transfer enhancement in latent heat thermal energy storage system by using the internally finned tube  

Microsoft Academic Search

The heat transfer enhancement in the latent heat thermal energy storage system by using an internally finned tube is presented in this paper. The phase change material fills the annular shell space around the tube, while the transfer fluid flows within the internally finned tube. The melting of the phase change material is described by a temperature transforming model coupled

Yuwen Zhang; A. Faghri

1996-01-01

138

Heat and storage effects on the flavour of peanuts.  

PubMed

Two peanut varieties, Giza 4 and Giza 5 were subjected to different heat treatments such as drying in solar drier at air speed 0.5 and 2 m/sec with average temperature 45 and 60 degrees C and heating in oven at 120 and 150 degrees C. The sensory evaluation of the two varieties showed insignificant differences among varieties and heating processes. A correlation between the sensory and instrumental data was found. The high sensory scores of samples heated at 150 degrees C were attributed to the presence of high concentration of pyrazines which were thought to contribute to flavour and aroma of fresh roasted peanut. A comparative study between the main chemical classes retained in peanut samples after storage for 3 months at room temperature showed that the aldehydes derived lipids increased significantly in the solar dried samples. The antioxidative components produced via Maillard reaction resulted in oxidative stability of the samples heated in oven. PMID:9881373

el-Kayati, S M; Fadel, H H; Abdel Mageed, M; Farghal, S A

1998-12-01

139

Variability in storage potential of banana shoot cultures under medium term storage conditions  

Microsoft Academic Search

Shoot cultures of 401 banana clones were conserved under slow growth conditions (16±1°C, 25µmol m-2 s-1). Storage duration-defined as 60% survival time of 20 shoot cultures of a clone-averaged 334 days. However, large differences occurred among the different genomic (sub)groups and even within the same (sub)group. East-African highland bananas and non-plantain AAB bananas can be stored for significantly longer periods.

Ines Van den houwe; Kris De Smet; Hugues Tezenas Montcel; Rony Swennen

1995-01-01

140

Integrated rock bed heat exchanger-cum-storage unit for residential-cum-water heating  

Microsoft Academic Search

This paper describes the results of a simulation study of a forced circulation, solar hybrid residential-cum-water heating system which comprises a corrugated absorber water heater and a rock-bed water-to-air heat exchanger-cum-storage unit integrated to a residential building to be heated. The system has been evaluated without and with the hot water load (which is the standard hot water demand for

C. Choudhury; H. P. Garg

1995-01-01

141

Solar-assisted heat pump and energy storage for residential heating  

Microsoft Academic Search

In order to investigate the performance of a solar-assisted heat pump system with energy storage for residential heating in the Black Sea region of Turkey, an experimental setup was constructed. This experimental apparatus consisted of flat plate solar collectors with total area of 30 m[sup 2], a laboratory building with 75 m[sup 2] floor area for heating purpose, a latent

O. Comakli; K. Kaygusuz; T. Ayhan

1993-01-01

142

Comparison of testing methods for latent-heat-storage devices  

SciTech Connect

ASHRAE Standard 94-77, Method of Testing Thermal Storage Devices Based on Thermal Performance, was developed to allow manufacturers of thermal energy storage devices to compare their products in a meaningful way. When Standard 94-77 was used for thermal energy storage products based on latent heat storage, the Standard was found to be inadequate for comparison of these devices. Standard Project Committee SPC 94.1 was established to devise a Standard that would be adequate for comparing latent heat systems. The purpose of this report is to describe several alternatives to Standard 94-77 and discuss the advantages and disadvantages of each alternative. The discussion focuses on two proposed replacement standards and includes experimental results for each. The experimental results are from tests conducted on a PCM storage tank that uses sodium thiosulphate as the PCM and water as the heat transfer fluid. The experimental arrangement is discussed in detail. The first proposed standard, which is here called the Yu Lwin Method, is substantially based on Standard 94-77. It attempts to solve the deficiencies of the old standard by more carefully defining the parameters associated with the test. In addition, a test for degradation with cycling is proposed as part of the standard. The basis for the charge and discharge tests is a constant inlet temperature to the PCM tank. This method is discussed in detail in Section II. The second proposed standard is that recommended to Project Committee SPC 94.1, as of September, 1982. This proposed standard differs considerably from Standard 94-77 in that the theoretical storage capacity is not part of the analysis, and that constant energy input and output are respectively used in the charge and discharge tests. This method is discussed in detail in Section III. The two proposed standards are compared in Section IV. In addition, this Section discusses other proposed methods. Conclusions and recommendations are presented in Section V.

Cole, R.L.; Hull, J.R.; Lwin, Y.; Cha, Y.S.

1983-02-01

143

Candidate Thermal Energy Storage Technologies for Solar Industrial Process Heat Applications.  

National Technical Information Service (NTIS)

A number of candidate thermal energy storage system elements were identified as having the potential for the successful application of solar industrial process heat. These elements which include storage media, containment and heat exchange are shown.

E. R. Furman

1979-01-01

144

Heat pipe cooling system for underground, radioactive waste storage tanks  

SciTech Connect

An array of 37 heat pipes inserted through the central hole at the top of a radioactive waste storage tank will remove 100,000 Btu/h with a heat sink of 70/sup 0/F atmospheric air. Heat transfer inside the tank to the heat pipe is by natural convection. Heat rejection to outside air utilizes a blower to force air past the heat pipe condenser. The heat pipe evaporator section is axially finned, and is constructed of stainless steel. The working fluid is ammonia. The finned pipes are individually shrouded and extend 35 ft down into the tank air space. The hot tank air enters the shroud at the top of the tank and flows downward as it is cooled, with the resulting increased density furnishing the pressure difference for circulation. The cooled air discharges at the center of the tank above the sludge surface, flows radially outward, and picks up heat from the radioactive sludge. At the tank wall the heated air rises and then flows inward to comple the cycle.

Cooper, K.C.; Prenger, F.C.

1980-02-01

145

Influence of geologic layering on heat transport and storage in an aquifer thermal energy storage system  

NASA Astrophysics Data System (ADS)

A modeling study was carried out to evaluate the influence of aquifer heterogeneity, as represented by geologic layering, on heat transport and storage in an aquifer thermal energy storage (ATES) system in Agassiz, British Columbia, Canada. Two 3D heat transport models were developed and calibrated using the flow and heat transport code FEFLOW including: a "non-layered" model domain with homogeneous hydraulic and thermal properties; and, a "layered" model domain with variable hydraulic and thermal properties assigned to discrete geological units to represent aquifer heterogeneity. The base model (non-layered) shows limited sensitivity for the ranges of all thermal and hydraulic properties expected at the site; the model is most sensitive to vertical anisotropy and hydraulic gradient. Simulated and observed temperatures within the wells reflect a combination of screen placement and layering, with inconsistencies largely explained by the lateral continuity of high permeability layers represented in the model. Simulation of heat injection, storage and recovery show preferential transport along high permeability layers, resulting in longitudinal plume distortion, and overall higher short-term storage efficiencies.

Bridger, D. W.; Allen, D. M.

2013-09-01

146

Light storage in a tripod medium as a basis for logical operations  

NASA Astrophysics Data System (ADS)

A photon being a carrier of a polarization qubit is stored inside an atomic medium in the tripod configuration in the form of atomic excitations. Such stored information can be processed in the atomic memory and carried away by the released photon. An implementation is proposed of single qubit gates, e.g., phase, NOT, NOT and Hadamard, as well as for a two-qubit CNOT gate, operating on polarized photons and based on light storage.

S?owik, K.; Raczy?ski, A.; Zaremba, J.; Zieli?ska-Kaniasty, S.

2012-05-01

147

Method, system, and storage medium for implementing intelligent team management services  

US Patent & Trademark Office Database

A method, system, and storage medium for implementing intelligent team management services. The method includes associating selected individuals with a datastore. The datastore houses content designated as key information and the selected individuals are designated as an entity. The method also includes creating a distribution list in a messaging application. The distribution list includes the selected individuals. The method further includes providing the selected individuals with access to the datastore.

Boss; Gregory J. (American Fork, UT); Hamilton, II; Rick A. (Charlottesville, VA); Jones; Andrew R. (Round Rock, TX); McConnell; Kevin C. (Austin, TX); Mitchell; Alan P. (Cedar Park, TX); Wentworth; Robert R. (Round Rock, TX)

2012-05-29

148

THE EFFECT OF STORAGE MEDIUM TONICITY ON OSTEOCHONDRAL AUTOGRAFT PLUG DIAMETER  

PubMed Central

Purpose The purpose of this study was to investigate the effect of differing storage medium on osteochondral plug diameter. Methods Four storage conditions were evaluated: air, hypotonic (sterile water), isotonic saline (0.9% NaCl), and hypertonic saline (3.0% NaCl). Four osteochondral plugs were acquired (4.5 mm harvesting system) from each of 10 fresh calf femurs and randomized to one of four storage media (n=40). Micro-CT was used to evaluate the precise diameter of each plug. Following a time zero scan, each plug was placed in a designated storage medium and rescanned at three time points over approximately one hour. A region of interest was identified from approximately 1 to 6 mm proximal to the tidemark. Custom software automatically calculated the diameter of each plug. Results The time zero plug diameter (mean ± CI) for all specimens was 4.66 ± 0.01 mm. There were no significant differences between any of the groups at the baseline scan. There were also no significant differences between the time zero and subsequent scans of the unsubmerged specimens. However, all of the liquid solutions (hypertonic, isotonic, and hypotonic) resulted in a significant increase in diameter from their baseline scans (p < 0.05), indicating a cause may be increased extracellular matrix fluid pressure. Conclusions Placing an osteochondral plug in a liquid solution increased the diameter of the subchondral bone. Size increase from the storage medium appeared to level off within 14 minutes after being placed in solution. Clinical Relevance Increases in diameter of the plug may alter the ease of insertion of the graft, possibly increasing contact pressure on cartilage during plug implantation.

Fening, Stephen D.; Mihnovets, Jonathon; Jones, Morgan H.; Midura, Ronald J.; Miniaci, Anthony

2010-01-01

149

A numerical study of the performance of latent heat storage for solar dynamic power systems  

Microsoft Academic Search

The structure and theoretical foundation of a simulation code for heat transfer and storage in an idealized storage module which forms part of a Brayton cycle solar power system are described. The underlying physical system is shown, and the advantages, drawbacks, and possible pitfalls of latent heat thermal energy storage are discussed. Some possible designs of a latent heat thermal

A. D. Solomon

1985-01-01

150

Quantification of subsurface heat storage in a GCM simulation  

NASA Astrophysics Data System (ADS)

Shallow bottom boundary conditions (BBCs) in the soil components of general circulation models (GCMs) impose artificial limits on subsurface heat storage. To assess this problem we estimate the subsurface heat content from two future climate simulations and compare to that obtained from an offline soil model (FDLSM) driven by GCM skin temperatures. FDLSM is then used as an offline substitute for the subsurface of the GCM ECHO-G. With a 600-m BBC and driven by ECHO-G future temperatures, the FDLSM subsurface absorbs 6.2 (7.5) times more heat than the ECHO-G soil model (10 m deep) under the Intergovernmental Panel on Climate Change (IPCC) A2 (B2) emission scenario. This suggests that shallow BBCs in GCM simulations may underestimate the heat stored in the subsurface, particularly for northern high latitudes. This effect could be relevant in assessing the energy balance and climate change in the next century.

MacDougall, Andrew H.; González-Rouco, J. Fidel; Stevens, M. Bruce; Beltrami, Hugo

2008-07-01

151

Heat storage system utilizing phase change materials government rights  

DOEpatents

A thermal energy transport and storage system is provided which includes an evaporator containing a mixture of a first phase change material and a silica powder, and a condenser containing a second phase change material. The silica powder/PCM mixture absorbs heat energy from a source such as a solar collector such that the phase change material forms a vapor which is transported from the evaporator to the condenser, where the second phase change material melts and stores the heat energy, then releases the energy to an environmental space via a heat exchanger. The vapor is condensed to a liquid which is transported back to the evaporator. The system allows the repeated transfer of thermal energy using the heat of vaporization and condensation of the phase change material.

Salyer, Ival O. (Dayton, OH)

2000-09-12

152

(Thermal energy storage technologies for heating and cooling applications)  

SciTech Connect

Recent results from selected TES research activities in Germany and Sweden under an associated IEA annex are discussed. In addition, several new technologies for heating and cooling of buildings and automobiles were reviewed and found to benefit similar efforts in the United states. Details of a meeting with Didier-Werke AG, a leading German ceramics manufacturer who will provide TES media necessary for the United States to complete field tests of an advanced high temperature latent heat storage material, are presented. Finally, an overview of the December 1990 IEA Executive Committee deliberations on TES is presented.

Tomlinson, J.J.

1990-12-19

153

Heat storage and distribution inside passive-solar buildings  

SciTech Connect

Passive-solar buildings are investigated from the viewpoint of the storage of solar heat in materials of the building: walls, floors, ceilings, and furniture. The effects of the location, material, thickness, and orientation of each internal building surface are investigated. The concept of diurnal heat capacity is introduced and a method of using this parameter to estimate clear-day temperature swings is developed. Convective coupling to remote rooms within a building is discussed, including both convection through single doorways and convective loops that may exist involving a sunspace. Design guidelines are given.

Balcomb, J.D.

1983-01-01

154

Trade-off between collector area, storage volume, and building conservation in annual-storage solar-heating systems  

SciTech Connect

Annual storage is used with active solar heating systems to permit storage of summertime solar heat for winter use. The results of a comprehensive computer simulation study of the performance of active solar heating systems with long-term hot water storage are presented. A unique feature of this study is the investigation of systems used to supply backup heat to passive solar and energy-conserving buildings, as well as to meet standard heating and hot water loads. Findings show that system output increases linearly as storage volume increases, up to the point where the storage tank is large enough to store all heat collected in summer. This point, the point of unconstrained operation, is the likely economic optimum. Unlike diurnal storage systems, annual storage systems show only slightly diminished efficiency as system size increases. Annual storage systems providing nearly 100% solar space heat may cost the same or less per unit heat delivered as a 50% diurnal solar system. Also in contrast to diurnal systems, annual storage systems perform efficiently in meeting the load of a passive or energy-efficient building.

Sillman, S.

1981-04-01

155

Constant Temperature Storage House Heated by the Respiration Heat of Agricultural Products  

NASA Astrophysics Data System (ADS)

HIMURO type storage house, cooled by natural snow/ice, has been practically applied by means of its good storing condition and of the easy handling. As this type storage house is constructed by enough insulation structure, it can been used not only for a cool house in the summer but also a constant temperature storage house in the winter. In this paper, the authors suggested that the HIMURO type storage house might be used as the constant temperature house in the severe cold winter season after the theoretical investigation on the thermal characteristics of it. In general, the conventional type constant temperature storage house is heated by heater throughout storing period, that of this paper is self heated by the respiration heat of agricultural products stored in this house, so the house proposed in this paper look forward to smaller heat addition than that of conventional house. The practical experiment was performed to verify the theoretical investigation and to observe the storing condition of the product and we obtained enough results.

Kobiyama, Masayoshi; Takegata, Kiyohide; Hashimoto, Yoshiaki; Kawamoto, Syuroh; Ohno, Syozi

156

Analysis and summary of a solar air collector-groundwater heat storage-greenhouse heating system  

SciTech Connect

An air-type solar energy collector with reflective wings at the top and bottom was developed and adapted to heat a soil and groundwater heat storage from which energy was reclaimed to heat a greenhouse. Collector efficiency correlation for summer and winter months are presented for seasonal collector tilts of 30/sup 0/ and 60/sup 0/, respectively. The collector performance data and correlations show that summer performance on an average was 30 percent better than winter months. In addition, a model for the determination of solar radiation augmentation due to reflectors is presented. The model shows total radiation increments of 25 percent and 18 percent for summer and winter seasons, compared to average reported value of 22 percent. A three dimension finite difference unsteady state model for determining heat transfer to and from pipes buried in soil was developed. Validation was done by comparing the actual and pedicted hourly soil temperature distribution values for typical summer and winter days. The standard deviation between actual and predicted hourly soil temperature values was + 0.83/sup 0/C. The greenhouse subsystem performance was documented by showing the weekly breakdown of a typical winter season heating requirement supplied by the solar and auxiliary heating systems. Only about 5 percent of the heating requirement was supplied by the solar system. This low system efficiency was attributed to the inability of storage unit to retain heat for an extended period of time due to rapid heat loss to the surroundings.

Dale, A.C.; Puri, V.M.; Barrett, J.R.; Hammer, P.A.

1981-01-01

157

Compressed air energy storage turbomachinery cycle with compression heat recovery, storage, steam generation and utilization during power generation  

Microsoft Academic Search

This patent describes a compressed Air Energy Storage (CAES) plant cycle which utilizes otherwise wasted compression heat by storing such heat in a thermal energy storage (TES) device for subsequent use for steam generation and injection into compressed air flow before entering a high pressure combustion which expands such compressed air to produce additional power. The cycle consists of the

Nakhamkin

1988-01-01

158

Development of heat storage building materials for passive solar applications  

SciTech Connect

The objective of this study was to develop a heat storage building material to be used for passive solar applications and load leveling within residential/commercial building spaces. Three phase change materials (PCMs) were evaluated for use in double-walled, hollow-channeled plastic panels as replacements for standard wallboard and ceiling panels. Performance tests conducted during this study indicate that the PCM-filled plastic panels can be completely charged/discharged on a daily basis by convective and radiative means. Typical PCM related problems with containment, nucleation, corrosiveness, incongruent melting, supercooling, heat transfer, and cycle lifetime have been addressed, and no significant barriers to future development are anticipated. Computer simulated comparisons of a PCM and conventionally fitted passive solar building indicate a significant improvement in heating requirements and thermal comfort using the PCM ceiling and wall panels. Overheating of the structure was also reduced dramatically during fall and spring months, substantially reducing cooling (ventilation) requirements.

Fletcher, J.W.; Price, J.M.; Tucker, S.P.

1984-02-01

159

Experimental validation of heat transfer models for flow through a porous medium  

Microsoft Academic Search

Unsteady heat transfer in a fluid saturated porous medium contained in a tube is studied. The porous medium is a bed of uniform diameter spheres, made of glass or steel, while the flowing fluid is water. The flow field is time invariant in the simulation as well as experiments. Step response of the bed when the temperature of the incoming

Chanpreet Singh; R. G. Tathgir; K. Muralidhar

2006-01-01

160

Thermal and heat transfer characteristics in a latent heat storage system using lauric acid  

Microsoft Academic Search

The thermal and heat transfer characteristics of lauric acid during the melting and solidification processes were determined experimentally in a vertical double pipe energy storage system. In this study, three important subjects were addressed. The first one is temperature distributions and temporal temperature variations in the radial and axial distances in the phase change material (PCM) during phase change processes.

Ahmet Sar?; Kamil Kaygusuz

2002-01-01

161

Thermal Energy Storage Heat Exchanger: Molten Salt Heat Exchanger Design for Utility Power Plants.  

National Technical Information Service (NTIS)

The use of thermal energy storage (TES) in the latent heat of molten salts as a means of conserving fossil fuels and lowering the cost of electric power was evaluated. Public utility systems provided electric power on demand. This demand is generally maxi...

A. Ferarra G. Yenetchi R. Haslett R. Kosson

1977-01-01

162

Thermal energy storage heat exchanger: Molten salt heat exchanger design for utility power plants  

Microsoft Academic Search

The use of thermal energy storage (TES) in the latent heat of molten salts as a means of conserving fossil fuels and lowering the cost of electric power was evaluated. Public utility systems provided electric power on demand. This demand is generally maximum during late weekday afternoons, with considerably lower overnight and weekend loads. Typically, the average demand is only

A. Ferarra; G. Yenetchi; R. Haslett; R. Kosson

1977-01-01

163

Sizing phase-change energy storage units for air-based solar heating systems  

Microsoft Academic Search

A simple method for sizing phase-change energy storage (PCES) units for air-based solar heating systems is presented. An effective heat capacity for the phase change unit is obtained as a function of its mass, latent heat, specific heat, and melting temperature. The effective heat capacity can then be used, along with any convenient design method for systems with sensible heat

J. J. Jurinak; S. I. Abdel-Khalik

1979-01-01

164

Rheological properties of concentrated skim milk: influence of heat treatment and genetic variants on the changes in viscosity during storage.  

PubMed

Heat treatment during manufacturing of milk powder is one of the most important tools for manipulation of its functional properties, and it is the basis of the classification of these proteins into low-, medium-, and high-heat types. Slight differences in the sequences of the major proteins in milk (genetic variants) seem to have also a significant effect in milk powder processing (U.S. patent). Therefore, the effects of high-temperature storage and heat treatment on skim milk of defined genetic variants of beta-lactoglobulin (beta-LG) were measured. The samples had 45% total solids, the temperature of aging was 50 degrees C, and the heat treatment was 90 degrees C for 10 min prior to evaporation. Measurements on shear rate and on apparent viscosity were determined for each sample. During storage of the concentrated milk, the apparent viscosity and yield values increased markedly, and the age-dependent increase in viscosity in heat-treated concentrated skim milks was much more pronounced than in those prepared from unheated skim milks. The increase in apparent viscosity and yield value with storage time was notably different for milks containing different genetic variants. Unheated concentrated milks containing the B variant of beta-LG showed the most rapid increase in apparent viscosity with storage time, whereas the viscosity increase was slowest in the concentrate containing the A variant. In contrast, heat-treated concentrated milks containing the A variant of beta-LG showed the most rapid increase in viscosity with storage time, whereas the viscosity increase was slowest in the concentrate containing the AB variant. The changes in apparent viscosity of concentrated milk were largely reversible under high shear during the early stages of storage, but samples stored for a long time showed irreversible changes in apparent viscosity. Particle size analysis confirmed irreversible aggregation and fusion of casein particles during storage. PMID:14558767

Bienvenue, Annie; Jiménez-Flores, Rafael; Singh, Harjinder

2003-10-22

165

Effects of the heat transfer fluid velocity on the storage characteristics of a cylindrical latent heat energy storage system: a numerical study  

Microsoft Academic Search

A numerical study of the effects of the thermal fluid velocity on the storage characteristics of a cylindrical latent heat energy storage system (LHESS) was conducted. Due to the low thermal conductivity of phase change materials (PCMs) used in LHESS, fins were added to the system to increase the rate of heat transfer and charging. Finite elements were used to

Wilson Ogoh; Dominic Groulx

2011-01-01

166

High Temperature Metal Hydrides as Heat Storage Materials for Solar and Related Applications  

PubMed Central

For the continuous production of electricity with solar heat power plants the storage of heat at a temperature level around 400 °C is essential. High temperature metal hydrides offer high heat storage capacities around this temperature. Based on Mg-compounds, these hydrides are in principle low-cost materials with excellent cycling stability. Relevant properties of these hydrides and their possible applications as heat storage materials are described.

Felderhoff, Michael; Bogdanovic, Borislav

2009-01-01

167

Heat storage and energy balance fluxes for a temperate deciduous forest  

Microsoft Academic Search

Hourly observations of forest-atmosphere energy balance components are presented for the Morgan-Monroe State Forest, south-central Indiana, USA for the period March 1998 to December 2001, with particular emphasis on the storage heat flux (?QS). The sub-components of ?QS showed strong diurnal variability, although ground heat flux dominated the seasonal change of storage heat flux. The annual storage heat balance for

A. J. Oliphant; C. S. B. Grimmond; H. N. Zutter; H. P. Schmid; H.-B. Su; S. L. Scott; B. Offerle; J. C. Randolph; J. Ehman

2004-01-01

168

Study of the effectiveness of propolis extract as a storage medium for avulsed teeth.  

PubMed

The purpose of the present study was to evaluate the efficacy of propolis extract in maintaining the viability of human periodontal ligament (PDL) cells, and to radiographically analyze tooth replantation and the adjacent periodontium in dogs after storage in this extract. Human PDL cells were incubated with the experimental media propolis, milk, saliva, Hank's balanced salt solution (HBSS), and Dulbecco's modified Eagles medium (DMEM, positive controls), and distilled water (negative control). Cell viability was determined 0, 1, 3, 6, 12, and 24 h later by colorimetric MTT assay. Thirty incisors from dogs were divided into two storage time blocks (1 and 3 h) and were maintained in the experimental media. HBSS served as a positive control, and dry teeth (on gauze) as a negative control. The replanted teeth were radiographed once per month for 6 months. The radiographic images were standardized by the shortening/lengthening factor, and were both qualitatively and quantitatively analyzed. The in vitro results showed that the efficacy of propolis in maintaining functional viability of PDL cells was similar to that of milk. Propolis and milk were significantly better than controls from the 6-h time period. The in vivo results showed that teeth maintained in propolis medium exhibited replacement resorption with significant reduction in tooth length, similar to teeth maintained in saliva and dried teeth. This resorption was less intense with the 3-h storage time than the 1-h storage time. Conditions close to normal were found in teeth maintained in milk, similar to the HBSS control. Therefore, although propolis was effective in maintaining the viability of human PDL cells, resorption of the tooth replantation in dogs occurred under these experimental conditions. PMID:20662885

Casaroto, Ana Regina; Hidalgo, Mirian Marubayashi; Sell, Ana Maria; Franco, Selma Lucy; Cuman, Roberto Kenji Nakamura; Moreschi, Eduardo; Victorino, Fausto Rodrigo; Steffens, Vânia Antunes; Bersani-Amado, Ciomar Aparecida

2010-08-01

169

Thermal energy storage by means of the latent heat of fusion of a mineral salt - Study of a direct contact dynamic exchanger with salt crystallization during flow  

Microsoft Academic Search

The use of a heat exchanger in which the storage medium (a mineral salt) comes into direct contact with the heat transfer agent for the recovery of thermal energy stored in molten salt is investigated. Preliminary experiments on heat transfer and phase separation in a mixture of a molten NaNO2, NaNO3, KNO3 eutectic (melting point 142 C) with a synthetic

J. Pantaloni; O. Favre; R. Bailleux; G. Finiels; J. Marchisio

1979-01-01

170

Particulate solids dryer with recycled hot-pebble heat exchange medium  

Microsoft Academic Search

This patent describes an apparatus for removing volatile substances from particulate solids material such as earth contaminated with hydrocarbon liquids and the like. The apparatus comprising: an elongated housing defining an interior space; an elongated conveyor screw in the housing; means for conducting combustion gasses through the chamber; a quantity of heat exchange medium; means for transferring the heat exchange

Baillie

1989-01-01

171

Transient coupled radiative–conductive heat transfer in a gray planar medium with anisotropic scattering  

Microsoft Academic Search

Transient radiative and conductive heat transfer in an absorbing, emitting and anisotropically scattering gray slab is investigated. The medium is confined within parallel walls and is excited by a heat pulse stimulation on the front face. The phase function corresponds to a second-degree anisotropic scattering and includes isotropic, linearly anisotropic and Rayleigh modes of scattering. The semi-analytical approach, based on

M. Lazard; S. Andre; D. Maillet

2001-01-01

172

Analysis of advanced thermal storage subsystems for solar heating and cooling  

Microsoft Academic Search

Computer models for heating, cooling, and advanced thermal storage subsystems were developed in TRNSYS-compatible form. Simplified models for solar collection and building loads were written, together with routines that simulate a variety of space conditioning and advanced storage devices. Simulations using various storage concepts were carried out for four applications: (1) space and domestic hot water heating; (2) solar assisted

P. O. Offenhartz; J. M. Marston; J. I. Watts

1979-01-01

173

Active heat exchange: System development for latent heat thermal energy storage  

NASA Astrophysics Data System (ADS)

An active heat exchange method in a latent heat (salt) thermal energy storage system that prevents a low conductivity solid salt layer from forming on heat transfer surfaces was developed. An evaluation of suitable media with melting points in the temperature range of interest (250 to 400 C) limited the candidates to molten salts from the chloride, hydroxide, and nitrate families, based on high storage capacity, good corrosion characteristics, and availability in large quantities at reasonable cost. The specific salt recommended for laboratory tests was a choride eutectic (20.5KCl, 24.5NaCl, 55.0MgCl2 percent by wt.), with a nominal melting point of 385 C.

Alario, J.; Haslett, R.

1981-03-01

174

Heating the Intracluster Medium with Distributed Cluster AGN: Observational Clues?  

NASA Astrophysics Data System (ADS)

Galaxy clusters are unique environments in which to study galaxy evolution and feedback mechanisms because they provide a means for directly viewing and measuring the heat ejected by AGN into their surroundings. The temperature profiles of clusters in their inner regions (r<500 kpc) are known to differ between cool-core (CC) and non-cool core (NCC) clusters, with the profile slopes correlated to the cooling time in those regions. Any form of heating should change the slope of the temperature profile, which we expect should be correlated to the total energy injection of the radio sources. If a distributed population of radio galaxies is responsible for heating the ICM, we expect to see changes in the slope of the temperature profile in clusters with and without radio-loud BCGs. Using archival data from the Sloan Digital Sky Survey, NVSS, FIRST, Chandra, and the Archive of Chandra Cluster Entropy Profile Tables (ACCEPT), we present our initial analysis of entropy profiles for several clusters with and without radio-loud BCGs.

Hart, Quyen N.

2013-01-01

175

Advanced latent heat storage media for high-temperature industrial applications  

NASA Astrophysics Data System (ADS)

Several advanced thermal energy storage (TES) media are being developed for high temperature industrial applications. One of the concepts involves a composite medium consisting of a phase-change carbonate salt supported and immobilized within a submicro sized capillary structure of a particulate ceramic matrix or porous sintered ceramic. Immobilization of the molten salt within the ceramic structure permits operation of the composite pellets, bricks, or other shapes in direct contact with compatible fluids. Energy storage occurs in both sensible and latent forms with the composite providing higher energy storage densities than standard sensible heat storage systems. The second concept centers on the development of a self-encapsulating metallic eutectic. This work focuses on metallic eutectics containing silicon. Starting with a silicon-rich mixture, it is feasible to develop a self-encapsulating pellet by cooling the liquid drops at a controlled rate. A solid of nearly pure silicon will form on the exterior of the pellet leaving a eutectic, phase change media in the interior. The concept are described and information concerning current development activities is presented.

Olszewski, M.

1984-03-01

176

Heat transfer in vertically aligned phase change energy storage systems  

SciTech Connect

Convection effects on heat transfer are analyzed in low temperature and vertically aligned phase change energy storage systems. This is performed by detailed temperature measurements in the phase change material (PCM) in eighteen locations forming a grid of six radial and three axial positions. The system constitutes a double pipe configuration, where commercial grade paraffin wax is stored in the annular space between the two pipes and water flows inside the inner pipe. Vertical alignment of the system allowed for reverse of the flow direction of the heat transfer fluid (HTF), which is water. Therefore, the PCM is heated from the bottom for HTF flow from bottom to top and from the top as the HTF flow direction is reversed. For the former case, natural convection affects the melting process. Collected data are used to study variations in the transient temperature distribution at axial and radial positions as well as for the two-dimensional temperature field. The data are used to calculate the PCM heat transfer coefficient and to develop correlations for the melting Fourier number. Results indicate that the PCM heat transfer coefficient is higher for the case of PCM heating from bottom to top. Nusselt number correlations are developed as a function of Rayleigh, Stefan, and Fourier numbers for the HTF flow from bottom to top and as a function of Stefan and Fourier numbers for HTF flow from top to bottom. The enhancement ratio for heat transfer caused by natural convection increases and then levels off as the inlet temperature of the HTF is increased.

El-Dessouky, H.T.; Bouhamra, W.S.; Ettouney, H.M.; Akbar, M. [Kuwait Univ., Safat (Kuwait). Dept. of Chemical Engineering

1999-05-01

177

Computational modeling of the heat exchange between the heat-transport medium and the air in a room with floor heating  

NASA Astrophysics Data System (ADS)

This paper presents the results of computational modeling of the heat exchange between the heat-transport medium and the air in a room with floor heating. The modeling results are comparable with experimental data. A good agreement between calculations and experiments is noted. Graphs of the floor heating loads for various pitches of pipe laying in the floor have been obtained by the method of computational modeling.

Basok, B. I.; Nedbailo, A. N.; Novitskaya, M. P.; Tkachenko, M. V.; Goncharuk, S. M.

2013-03-01

178

Heat Storage Capacity of Selected New England Rocks, July 1979-July 1980.  

National Technical Information Service (NTIS)

Specific heat, density and heat storage capacity values have been determined for thirteen lithologies which encompass the common lithologies present in New England. The highest value of heat storage capacity encountered was .627 cal./cc exp 0 C for a mang...

T. Brewer

1980-01-01

179

Latent heat storage technology and application workshop. Summary report: Session 6  

NASA Astrophysics Data System (ADS)

Latent heat storage technology and application were studied. The economics of short term latent heat storage for application and system configuration were analyzed. Subjects discussed included: state of the art, solar energy stores, residential heating and cooling, and industrial and utility applications.

Martin, J. F.

180

The analysis of GSHP radiant floor heating with PCM for energy storage  

Microsoft Academic Search

Based on the prominent position of constructing resource conservation and environmental-friendly society in the industrialization and modernization developmental strategy, this paper compared the GSHP, radiant floor heating system, PCM for heat storage with its corresponding style, conceived a new energy system-GSHP radiant floor heating system with PCM for energy storage. This paper had analyzed the influences of water supply temperature,

Wang Jinggang; Kang Ligai; Zhao Jinxiu

2009-01-01

181

Enhanced Solar Assisted Building Ventilation System Using Sphere Encapsulated PCM Thermal Heat Storage  

Microsoft Academic Search

In the article we are presenting the design of latent heat storage with small polyethylene spheres with encapsulated PCM, which forms porous media inside the duct of the building ventilation system. In this study we assumed that ambient air is first heated in solar roof, than passes trough latent heat storage and at the end enters into living spaces as

C. ARKAR; S. MEDVED

182

Markvaermevaexlare foer hoegtemperaturlager i lera. (Ground heat exchangers for high temperature storage in clay).  

National Technical Information Service (NTIS)

For high temperature heat storage in clays, efficient heat exchangers are crucial components of the system. Different shapes of PEX tubes have been tested in heat storage computer simulations, e.g. U-forms and helix forms. In field tests it was found that...

M. Lehtmets C. Magnusson

1991-01-01

183

Mathematical modelling of a domestic heating system with stratified storage tank  

Microsoft Academic Search

A hybrid distributed parameter model of a heating system for domestic hot water is presented in this paper. This heating system comprises a condensing boiler (burner), a counter current heat exchanger, and a so-called stratified storage tank which is the state of the art domestic hot water storage unit. The paper presents the model for the different operational modes of

T. Kreuzinger; M. Bitzer; W. Marquardt

2008-01-01

184

Thermal performance of a latent heat energy storage ventilated panel for electric load management  

Microsoft Academic Search

A theoretical study was conducted to assess the thermal performance of a ventilated panel heating unit. The unit employs the latent heat energy storage method to level the electrical energy demand for domestic space heating during peak hours. A one-dimensional, semi-empirical model was developed to predict the dynamic thermal behavior of the storage unit under cyclic melting and solidification. The

A. Laouadi; M. Lacroix

1999-01-01

185

Specific heat variations in oil energy storage media and their economic implications  

Microsoft Academic Search

Hydrocarbon oils were investigated for use as thermal energy storage media in solar thermal electric systems. In systems storing the energy as sensible heat, the energy storage capacity is determined by the specific heat of the oil. Among the oils studied is Caloria HT-43. Previously reported specific heat data on Caloria HT-43 show values differing by as much as 25

R. W. Carling; L. G. Radosevich

1978-01-01

186

Physical Properties and Heat Transfer Characteristics of Materials for Krypton-85 Storage.  

National Technical Information Service (NTIS)

Krypton-85 decay results in heat generation, and the subsequent temperature increase in the krypton-85 storage media must be evaluated. This report compiles the physical properties of krypton and of potential krypton-85 storage materials which are require...

A. B. Christensen

1977-01-01

187

Aquifer thermal energy storage costs with a seasonal heat source.  

SciTech Connect

The cost of energy supplied by an aquifer thermal energy storage (ATES) system from a seasonal heat source was investigated. This investigation considers only the storage of energy from a seasonal heat source. Cost estimates are based upon the assumption that all of the energy is stored in the aquifer before delivery to the end user. Costs were estimated for point demand, residential development, and multidistrict city ATES systems using the computer code AQUASTOR which was developed specifically for the economic analysis of ATES systems. In this analysis the cost effect of varying a wide range of technical and economic parameters was examined. Those parameters exhibiting a substantial influence on ATES costs were: cost of purchased thermal energy; cost of capital; source temperature; system size; transmission distance; and aquifer efficiency. ATES-delivered energy costs are compared with the costs of hot water heated by using electric power or fuel-oils. ATES costs are shown as a function of purchased thermal energy. Both the potentially low delivered energy costs available from an ATES system and its strong cost dependence on the cost of purchased thermal energy are shown. Cost components for point demand and multi-district city ATES systems are shown. Capital and thermal energy costs dominate. Capital costs, as a percentage of total costs, increase for the multi-district city due to the addition of a large distribution system. The proportion of total cost attributable to thermal energy would change dramatically if the cost of purchased thermal energy were varied. It is concluded that ATES-delivered energy can be cost competitive with conventional energy sources under a number of economic and technical conditions. This investigation reports the cost of ATES under a wide range of assumptions concerning parameters important to ATES economics. (LCL)

Reilly, R.W.; Brown, D.R.; Huber, H.D.

1981-12-01

188

Quality of shell eggs pasteurized with heat or heat-ozone combination during extended storage.  

PubMed

The physical quality and functionality of shell eggs, pasteurized with heat or a combination of heat and ozone, were assessed during eight weeks of storage at 4 or 25 °C. Shell eggs were treated as follows: (1) immersion heating that mimics commercial pasteurization processes (egg internal temperature of 56 ± 0.1 °C for 32 min), or (2) a newly developed combination process comprised of heating (56 ± 0.1 °C, internal, for 10 min) followed by gaseous ozone treatment. Eggs were tested for yolk index, Haugh units, albumen pH, albumen turbidity, and percent overrun. Additionally, albumen samples were assayed for lysozyme activity and free sulfhydryl group content, and were analyzed using differential scanning calorimetry and Fourier transform infrared (FTIR) spectroscopy. Both processed and unprocessed eggs maintained superior quality when stored at 4 °C, as opposed to 25 °C. Pasteurization, regardless of method, led to superior maintenance of Haugh units during storage but also increased albumen opacity and decreased albumen overrun. Detrimental effects on quality markers were more severe in heat-pasteurized eggs than those treated with the ozone-based process. Pasteurization of shell eggs by either process did not affect lysozyme activity or sulfhydryl group content. Changes in protein secondary structure, as indicated by FTIR analysis, suggest that the ozone-based process is less damaging to albumen proteins than is the heat-alone process. In conclusion, heat-ozone pasteurization, by virtue of its less severe heat treatment, yields a safe final product that more closely resembles untreated shell eggs. PMID:21819400

Perry, J J; Rodriguez-Saona, L E; Yousef, A E

2011-08-05

189

Magnesium fluoride as energy storage medium for spacecraft solar thermal power systems  

SciTech Connect

MgF2 was investigated as a phase-change energy-storage material for LEO power systems using solar heat to run thermal cycles. It provides a high heat of fusion per unit mass at a high melting point (1536 K). Theoretical evaluation showed the basic chemical compatibility of liquid MgF2 with refractory metals at 1600 K, though transient high pressures of H2 can occur in a closed container due to reaction with residual moisture. The compatibility was tested in two refractory metal containers for over 2000 h. Some showed no deterioration, while there was evidence that the fluoride reacted with hafnium in others. Corollary tests showed that the MgF2 supercooled by 10-30 K and 50-90 K. 24 refs.

Lurio, C.A. (Aerodyne Research, Inc., Billerica, MA (United States))

1992-10-01

190

Experimental determination of soil heat storage for the simulation of heat transport in a coastal wetland  

USGS Publications Warehouse

Two physical experiments were developed to better define the thermal interaction of wetland water and the underlying soil layer. This information is important to numerical models of flow and heat transport that have been developed to support biological studies in the South Florida coastal wetland areas. The experimental apparatus consists of two 1.32. m diameter by 0.99. m tall, trailer-mounted, well-insulated tanks filled with soil and water. A peat-sand-soil mixture was used to represent the wetland soil, and artificial plants were used as a surrogate for emergent wetland vegetation based on size and density observed in the field. The tanks are instrumented with thermocouples to measure vertical and horizontal temperature variations and were placed in an outdoor environment subject to solar radiation, wind, and other factors affecting the heat transfer. Instruments also measure solar radiation, relative humidity, and wind speed.Tests indicate that heat transfer through the sides and bottoms of the tanks is negligible, so the experiments represent vertical heat transfer effects only. The temperature fluctuations measured in the vertical profile through the soil and water are used to calibrate a one-dimensional heat-transport model. The model was used to calculate the thermal conductivity of the soil. Additionally, the model was used to calculate the total heat stored in the soil. This information was then used in a lumped parameter model to calculate an effective depth of soil which provides the appropriate heat storage to be combined with the heat storage in the water column. An effective depth, in the model, of 5.1. cm of wetland soil represents the heat storage needed to match the data taken in the tank containing 55.9. cm of peat/sand/soil mix. The artificial low-density laboratory sawgrass reduced the solar energy absorbed by the 35.6. cm of water and 55.9. cm of soil at midday by less than 5%. The maximum heat transfer into the underlying peat-sand-soil mix lags behind maximum solar radiation by approximately 2. h. A slightly longer temperature lag was observed between the maximum solar radiation and maximum water temperature both with and without soil. ?? 2012 Elsevier B.V.

Swain, M.; Swain, M.; Lohmann, M.; Swain, E.

2012-01-01

191

Effect of aeration on minimal medium recovery of heated Salmonella typhimurium.  

PubMed Central

The effect of presence or absence of air on minimal medium recovery of heated Salmonella typhimurium was investigated. It was determined that the expression of minimal medium recovery is not only dependent on heat and a nutritionally complex medium but also on air. Unlike in the presence of air, in the presence of nitrogen, cells were able to recover their ability to grow on Trypticase soy agar enriched with 0.5% yeast extract (TSY) when incubated in TSY broth. It was established that in the presence of nitrogen the number of heat-TSY- induced, single-straneded breaks in deoxyribonucleic acid (DNA) were less than in the presence of air. Furthermore, the DNA breaks in nitrogen were repaired, whereas DNA breaks in air were not. The ability of cells to grow on TSY agar corresponded well with their ability to repair damage to DNA.

Gomez, R F; Sinskey, A J

1975-01-01

192

Hydrogen storage system based on novel carbon materials and heat pipe heat exchanger  

Microsoft Academic Search

Adsorbed hydrogen is being considered as a potential energy carrier for vehicular applications to replace compressed gas due to its high energy density capability. A new design of hydrogen storage vessel using novel carbon sorbents and heat pipes thermal control is the subject of research program oriented on 5–10 kg of hydrogen be stored on-board. Porous structure and hydrogen-sorption capacities

L. L. Vasiliev; L. E. Kanonchik; A. G. Kulakov; V. A. Babenko

2007-01-01

193

Modeling the Performance of a Solar Heated Sunroom: Heat Gain, Storage and Loss  

NSDL National Science Digital Library

In this module students build, explore and modify dynamic simulation models of solar gain, heat storage, transfer and loss in a sunroom. The objective of this module is to provide students with a practical example of how basic mathematical formulations and a variety of simplifying assumptions can be combined to develop a model that can be used to improve system design, analyze system performance, and explore the efficacy of different management approaches for optimizing thermal performance.

Petersen, John E.; Fernandez-Gonzalez, Alfredo

194

Effect of deoxidation and heat treatment on the fatigue strength of cast medium-carbon steel  

Microsoft Academic Search

1.Deoxidizing treatment of steel, which determines the nature and shape of nonmetallic inclusions, has a definite effect on its fatigue strength.2.Deoxidation with calcium suicide increases the fatigue limit of cast medium-carbon steel and extends the limited endurance range.3.A substantial increase in fatigue strength of medium-carbon steel is produced by a heat treatment which relieves thermal stresses and leads to the

V. P. Rudenko; I. P. Volchok; V. V. Lunev; G. V. Karpenko; Yu. A. Shul'te; P. A. Mikhailov; A. B. Kuslitskii

1967-01-01

195

Transient couple heat transfer in an absorbing rectangular medium with one semitransparent diffuse boundary  

NASA Astrophysics Data System (ADS)

This paper studies 2-D transient coupled radiative and conductive heat transfer in an absorbing non-scattering rectangular medium. The medium have one diffuse semitransparent boundary, and the other three boundaries are black. The reflectivity of the diffuse semitransparent boundary is determined by integrating the reflected energy over the whole hemispherical space according to the Fresnel’s reflective law and Snell’s refractive law based on assuming each bit of the rough surface to be optically smooth.

Luo, Jian-Feng; Yi, Hong-Liang; Tan, He-Ping

2010-10-01

196

Heat treatment and mechanical stability behaviour of medium-carbon TRIP-aided bainitic steel  

Microsoft Academic Search

Purpose: The aim of the paper is to determine the influence of the isothermal holding conditions in a range of bainitic transformation on the mechanical stability of retained austenite for medium-carbon TRIP-aided steel. Design\\/methodology\\/approach: The examinations were carried out on medium-carbon steel containing 0.55%C and 1.35%Si. The conditions of heat treatment consisted of isothermal quenching of the specimens to a

A. Grajcar

197

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

SciTech Connect

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

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

1986-12-01

198

General Heat Transfer Characterization and Empirical Models of Material Storage Temperatures for the Los Alamos Nuclear Materials Storage Facility  

SciTech Connect

The Los Alamos National Laboratory's Nuclear Materials Storage Facility (NMSF) is being renovated for long-term storage of canisters designed to hold heat-generating nuclear materials. A fully passive cooling scheme, relying on the transfer of heat by conduction, free convection, and radiation has been proposed as a reliable means of maintaining material at acceptable storage temperatures. The storage concept involves placing radioactive materials, with a net heat-generation rate of 10 W to 20 W, inside a set of nested steel canisters. The canisters are, in placed in holding fixtures and positioned vertically within a steel storage pipe. Several hundred drywells are arranged in a linear array within a large bay and dissipate the waste heat to the surrounding air, thus creating a buoyancy driven airflow pattern that draws cool air into the storage facility and exhausts heated air through an outlet stack. In this study, an experimental apparatus was designed to investigate the thermal characteristics of simulated nuclear materials placed inside two nested steel canisters positioned vertically on an aluminum fixture plate and placed inside a section of steel pipe. The heat-generating nuclear materials were simulated with a solid aluminum cylinder containing .an embedded electrical resistance heater. Calibrated type T thermocouples (accurate to ~ O.1 C) were used to monitor temperatures at 20 different locations within the apparatus. The purposes of this study were to observe the heat dissipation characteristics of the proposed `canister/fixture plate storage configuration, to investigate how the storage system responds to changes in various parameters, and to develop and validate empirical correlations to predict material temperatures under various operating conditions

J. D. Bernardin; W. S. Gregory

1998-10-01

199

A review of materials, heat transfer and phase change problem formulation for latent heat thermal energy storage systems (LHTESS)  

Microsoft Academic Search

This paper reviews the development of latent heat thermal energy storage systems studied detailing various phase change materials (PCMs) investigated over the last three decades, the heat transfer and enhancement techniques employed in PCMs to effectively charge and discharge latent heat energy and the formulation of the phase change problem. It also examines the geometry and configurations of PCM containers

Francis Agyenim; Neil Hewitt; Philip Eames; Mervyn Smyth

2010-01-01

200

The heat flow field of the intermediate heating medium inside of the cylinder type natural gas heater  

NASA Astrophysics Data System (ADS)

The cylinder type natural gas heater with intermediate heating medium has been most widely used in gas industry. Therefore, the present paper explores the structural characteristics and the heat transfer mechanism inside of the cylinder. According to the distinctive heat transfer structure of the cylinder type natural gas heater, the natural convection heat transfer model of both heating surfaces and cooling surfaces in the cylinder is built. The unstructured Cartesian grid finite method is employed and thus these grids are fully body fitted. The temperature distribution and velocity vector inside the cylindrical natural gas heater are numerically simulated. The simulation results show that the conventional symmetrical arrangement of heating and cooling surfaces is not conducive to the formation of an effective heat flow field. An effective measure of rotating the symmetrical layout structure at a certain angle is put forward creatively, which can optimize the overall heat transfer effect of the heater. Analysis and comparison of the heat flow field of the cylindrical natural gas heater in different rotation angle are carried out. The numerical simulation shows the best rotation angle is 20~30°. The technology has got itself the China invention patent.

Guo, Yun; Cao, Weiwu

2013-07-01

201

Transient characteristics and performance of a novel desalination system based on heat storage and spray flashing  

Microsoft Academic Search

A hybrid latent heat storage and spray flash evaporation system has been devised in an attempt to develop an energy saving desalination system that stores intermittent thermal energy such as waste heat, solar heat or heat from the surplus steam of a power station at night and utilizes the stored energy not only for the generation of process steam from

Osamu Miyatake; Yasushi Koito; Kotaro Tagawa; Yasuhiro Maruta

2001-01-01

202

Preparation and application effects of a novel form-stable phase change material as the thermal storage layer of an electric floor heating system  

Microsoft Academic Search

A novel form-stable phase change material (FSPCM) was prepared, which comprises micro-encapsulated paraffin (MEP) as the latent heat storage medium and high density polyethylene\\/wood flour composite as the matrix. It has the following merits: proper phase transition temperature, large apparent specific heat in phase change temperature region, suitable thermal conductivity, good shape retention and dimensional stability. Therefore, it is suitable

Jianli Li; Ping Xue; Hong He; Wenying Ding; Jinmin Han

2009-01-01

203

Heat transfer characteristics of thermal energy storage system using PCM capsules: A review  

Microsoft Academic Search

Thermal energy storage has recently attracted increasing interest related to thermal applications such as space and water heating, waste heat utilization, cooling and air-conditioning. Energy storage is essential whenever there is a mismatch between the supply and consumption of energy. Use of phase change material (PCM) capsules assembled as a packed bed is one of the important methods that has

A. Felix Regin; S. C. Solanki; J. S. Saini

2008-01-01

204

Thermal performance of PCM thermal storage unit for a roof integrated solar heating system  

Microsoft Academic Search

The thermal performance of a phase change thermal storage unit is analysed and discussed. The storage unit is a component of a roof integrated solar heating system being developed for space heating of a home. The unit consists of several layers of phase change material (PCM) slabs with a melting temperature of 29°C. Warm air delivered by a roof integrated

W. Saman; F. Bruno; E. Halawa

2005-01-01

205

Specific Heat Variations in Oil Energy Storage Media and Their Economic Implications.  

National Technical Information Service (NTIS)

Hydrocarbon oils have been considered for use as thermal energy storage media in solar thermal electric systems. In systems storing the energy as sensible heat, the energy storage capacity is determined by the specific heat of the oil. Among the oils prop...

R. W. Carling L. G. Radosevich

1978-01-01

206

A numerical study of the performance of latent heat storage for solar dynamic power systems  

NASA Astrophysics Data System (ADS)

The structure and theoretical foundation of a simulation code for heat transfer and storage in an idealized storage module which forms part of a Brayton cycle solar power system are described. The underlying physical system is shown, and the advantages, drawbacks, and possible pitfalls of latent heat thermal energy storage are discussed. Some possible designs of a latent heat thermal energy storage module are examined. Preliminary results obtained by using analytical approximations which are crucial to 'homing in' on potential system configurations are reported and examined using the simulation code.

Solomon, A. D.

1985-12-01

207

Measurements of heating and energy storage in diode-pumped Nd:YAG  

Microsoft Academic Search

Two experiments were carried out to measure the stored energy and heat deposited in the laser medium and to determine the heat parameter ?, defined as the heat deposited per unit of stored energy. The stored energy was calculated from small-signal gain measurements. The heat deposition was calculated from interferometric measurements of the thermally induced optical path length changes of

T. S. Chen; V. L. Anderson; O. Kahan

1990-01-01

208

An efficient way to use medium-or-low temperature solar heat for power generation – integration into conventional power plant  

Microsoft Academic Search

This paper demonstrates that the medium-or-low temperature solar heat can be used to generate power efficiently by integrating into conventional coal-fired power plants. In so-called solar aided power generation (SAPG) technology, medium-or-low temperature solar heat is used to replace parts of bled-off steams in regenerative Rankine cycle to pre-heat feedwater. Thermal oil can be used as solar heat carrier and

Yongping Yang; Qin Yan; Rongrong Zhai; Abbas Kouzani; Eric Hu

2011-01-01

209

Performance of underground heat storage system in a double-film-covered greenhouse*  

PubMed Central

An underground heat storage system in a double-film-covered greenhouse and an adjacent greenhouse without the heat storage system were designed on the basis of plant physiology to reduce the energy consumption in greenhouses. The results indicated that the floor temperature was respectively 5.2 °C, 4.6 °C and 2.0 °C higher than that of the soil in the adjacent reference greenhouse after heat storage in a clear, cloudy and overcast sky in winter. Results showed that the temperature and humidity were feasible for plant growth in the heat saving greenhouse.

Wang, Yong-Wei; Liang, Xi-Feng

2006-01-01

210

Experimental investigation on a combined sensible and latent heat storage system integrated with constant\\/varying (solar) heat sources  

Microsoft Academic Search

The objective of the present work is to investigate experimentally the thermal behavior of a packed bed of combined sensible and latent heat thermal energy storage (TES) unit. A TES unit is designed, constructed and integrated with constant temperature bath\\/solar collector to study the performance of the storage unit. The TES unit contains paraffin as phase change material (PCM) filled

N. Nallusamy; S. Sampath; R. Velraj

2007-01-01

211

Evidence for an Additional Heat Source in the Warm Ionized Medium of Galaxies  

NASA Astrophysics Data System (ADS)

Spatial variations of the [S II]/H? and [N II]/H? line intensity ratios observed in the gaseous halo of the Milky Way and other galaxies are inconsistent with pure photoionization models. They appear to require a supplemental heating mechanism that increases the electron temperature at low densities, n_e. This would imply that in addition to photoionization, which has a heating rate per unit volume proportional to n^2_e, there is another source of heat with a rate per unit volume proportional to a lower power of n_e. One possible mechanism is the dissipation of interstellar plasma turbulence, which, according to Minter & Spangler, heats the ionized interstellar medium in the Milky Way at a rate of ~1x10^-25n_e ergs cm^-3 s^-1. If such a source were present, it would dominate over photoionization heating in regions where n_e<~0.1 cm^-3, producing the observed increases in the [S II]/H? and [N II]/H? intensity ratios at large distances from the galactic midplane as well as accounting for the constancy of [S II]/[N II], which is not explained by pure photoionization. Other supplemental heating sources, such as magnetic reconnection, cosmic rays, or photoelectric emission from small grains, could also account for these observations, provided they supply ~10^-5 ergs s^-1 per square centimeter of the Galactic disk to the warm ionized medium.

Reynolds, R. J.; Haffner, L. M.; Tufte, S. L.

1999-11-01

212

Evidence for an Additional Heat Source in the Warm Ionized Medium of Galaxies.  

PubMed

Spatial variations of the [S ii]/Halpha and [N ii]/Halpha line intensity ratios observed in the gaseous halo of the Milky Way and other galaxies are inconsistent with pure photoionization models. They appear to require a supplemental heating mechanism that increases the electron temperature at low densities, ne. This would imply that in addition to photoionization, which has a heating rate per unit volume proportional to n2e, there is another source of heat with a rate per unit volume proportional to a lower power of ne. One possible mechanism is the dissipation of interstellar plasma turbulence, which, according to Minter & Spangler, heats the ionized interstellar medium in the Milky Way at a rate of approximately 1x10-25ne ergs cm-3 s-1. If such a source were present, it would dominate over photoionization heating in regions where ne less, similar0.1 cm-3, producing the observed increases in the [S ii]/Halpha and [N ii]/Halpha intensity ratios at large distances from the galactic midplane as well as accounting for the constancy of [S ii]/[N ii], which is not explained by pure photoionization. Other supplemental heating sources, such as magnetic reconnection, cosmic rays, or photoelectric emission from small grains, could also account for these observations, provided they supply approximately 10-5 ergs s-1 per square centimeter of the Galactic disk to the warm ionized medium. PMID:10511504

Reynolds; Haffner; Tufte

1999-11-01

213

Evaluation, using extracted human teeth, of Ricetral as a storage medium for avulsions--an in vitro study.  

PubMed

The prognosis of teeth replanted following avulsion is determined by the extra-alveolar time and storage medium used. This study was undertaken to determine the efficacy of an oral rehydration solution 'Ricetral', in retaining the vitality of periodontal ligament cells when used as a storage medium for avulsed teeth prior to replantation. The study consisted of a comparative evaluation between Ricetral and two currently recommended solutions, Hank's balanced salt solution (HBSS) and milk. Thirty extracted teeth were dried for 30min and soaked in the respective storage media for 45min. The periodontal ligament cells were isolated by an enzyme treatment with collagenase and trypsin. The cells were evaluated for vitality by trypan blue staining and number of vital cells counted in a hemocytometer. Statistical analysis revealed that cell vitality was high with Ricetral and HBSS, but poor with milk. PMID:21535405

Rajendran, Priya; Varghese, Nettiyat Oommen; Varughese, Jolly Mary; Murugaian, Elango

2011-04-27

214

Analysis of cooling cycles with clathrate energy storage  

Microsoft Academic Search

A prototype is presented of a thermal energy storage facility, with an appropriate storage medium, that can be applicable in environmental control of residential and commercial buildings. A simulated heat pump cooling system which utilizes a refrigerant gas hydrate as a storage medium was experimentally and theoretically analyzed. Numerous closed loop cycles using a clathrate in direct contact heat transfer

Gadalla

1988-01-01

215

Evaluation of the HB&L System for the Microbiological Screening of Storage Medium for Organ-Cultured Corneas  

PubMed Central

Aims. To compare HB&L and BACTEC systems for detecting the microorganisms contaminating the corneal storage liquid preserved at 31°C. Methods. Human donor corneas were stored at 4°C followed by preservation at 31°C. Samples of the storage medium were inoculated in BACTEC Peds Plus/F (aerobic microorganisms), BACTEC Plus Anaerobic/F (anaerobic microorganisms), and HB&L bottles. The tests were performed (a) after six days of storage, (b) end of storage, and (c) after 24 hours of preservation in deturgescent liquid sequentially. 10,655 storage and deturgescent media samples were subjected to microbiological control using BACTEC (6-day incubation) and HB&L (24-hour incubation) systems simultaneously. BACTEC positive/negative refers to both/either aerobic and anaerobic positives/negatives, whereas HB&L can only detect the aerobic microbes, and therefore the positives/negatives depend on the presence/absence of aerobic microorganisms. Results. 147 (1.38%) samples were identified positive with at least one of the two methods. 127 samples (134 identified microorganisms) were positive with both HB&L and BACTEC. 14 HB&L+/BACTEC? and 6 BACTEC+/HB&L? were identified. Sensitivity (95.5%), specificity (99.8%), and positive (90.1%) and negative predictive values (99.9%) were high with HB&L considering a 3.5% annual contamination rate. Conclusion. HB&L is a rapid system for detecting microorganisms in corneal storage medium in addition to the existing methods.

Camposampiero, D.; Grandesso, S.; Zanetti, E.; Mazzucato, S.; Solinas, M.; Parekh, M.; Frigo, A. C.; Gion, M.; Ponzin, D.

2013-01-01

216

Thermal energy storage systems using fluidized bed heat exchangers  

NASA Astrophysics Data System (ADS)

A rotary cement kiln and an electric arc furnace were chosen for evaluation to determine the applicability of a fluid bed heat exchanger (FBHX) for thermal energy storage (TES). Multistage shallow bed FBHX's operating with high temperature differences were identified as the most suitable for TES applications. Analysis of the two selected conceptual systems included establishing a plant process flow configuration, an operational scenario, a preliminary FBHX/TES design, and parametric analysis. A computer model was developed to determine the effects of the number of stages, gas temperatures, gas flows, bed materials, charge and discharge time, and parasitic power required for operation. The maximum national energy conservation potential of the cement plant application with TES is 15.4 million barrels of oil or 3.9 million tons of coal per year. For the electric arc furnance application the maximum national conservation potential with TES is 4.5 million barrels of oil or 1.1 million tons of coal per year. Present time of day utility rates are near the breakeven point required for the TES system. Escalation of on-peak energy due to critical fuel shortages could make the FBHX/TES applications economically attractive in the future.

Weast, T.; Shannon, L.

1980-06-01

217

Numerical simulation of solar assisted ground-source heat pump heating system with latent heat energy storage in severely cold area  

Microsoft Academic Search

Solar assisted ground-source heat pump (SAGSHP) heating system with latent heat energy storage tank (LHEST) is investigated. The mathematical model of the system is developed, and the transient numerical simulation is carried out in terms of this model. The operation characteristic of the heating system is analyzed during the heating period in Harbin (N45.75°, E126.77°). From the results of the

Zongwei Han; Maoyu Zheng; Fanhong Kong; Fang Wang; Zhongjian Li; Tian Bai

2008-01-01

218

Natural convective boundary-layer flow in a heat generating porous medium with a prescribed wall heat flux  

NASA Astrophysics Data System (ADS)

The free convection boundary-layer flow on a vertical surface in a porous medium with local heat generation proportional to ( T - T ?) p , where T is the local temperature and T ? is the ambient temperature, is considered when the surface is thermally insulated. The way in which the flow develops from the leading edge is seen to depend critically on the exponent p. For p ? 2 there is a boundary-layer flow for all x > 0, where x measures distance from the leading edge, with the internal heating having a significant effect at large x. For p ? 5 there is also a boundary-layer flow to large x but now the internal heating has an increasingly weaker effect as x increases. For 2 < p < 5 the boundary-layer solution breaks down at a finite x, with a singularity developing leading to thermal runaway at a finite distance along the surface.

Merkin, J. H.

2009-05-01

219

Research of Operation Modes of Heat Storage Tank in CHP Plant Using Numerical Simulation  

NASA Astrophysics Data System (ADS)

The installation of a heat storage tank is a very cost-effective way to improve the performance and flexibility of a CHP plant. Such a heat storage tank usually accumulates heat by thermal stratification. This phenomenon is caused by the thermal buoyancy because of the difference in temperature between cold and hot water. The heat storage tank may have three operating modes, i. e. charge, discharge and storage in a CHP plant. When CHP units, which charge the heat storage tank, operate at full load, usually only two operation modes occur in the tank, i.e. charge and discharge. The paper presents numerical simulation of heat storage tank operation modes in a CHP plant using PHOENICS - a multi-purpose computation fluid dynamics (CFD) software. Two-dimensional and three-dimensional transient models were created and solved numerically. Three domain grids were tested. Several charging and discharging processes with different flow rates were simulated. The influence of flow rate on the degree of thermal stratification during charging and discharging processes is analyzed. The computation possibilities and limitations of the numerical experiments are pointed out. Special attention is given to the validation of the numerical solutions. The validation of simulated results is made by comparison with the real data from the heat storage installed in the Hvide Sande CHP plant.

Streckiene, Giedre; Miseviciute, Violeta

2011-01-01

220

Latent heat storage modules for preheating internal combustion engines: application to a bus petrol engine  

Microsoft Academic Search

The heat storage (HS) system for pre-heating a bus petrol engine before its ignition was mathematically modelled and experimentally investigated. The development of such devices is an extremely urgent problem especially for regions with a cold climate. HS system working on the effect of absorption and rejection of heat during the solid-liquid phase change of HS material is realised, tested

L. L. Vasiliev; V. S. Burak; A. G. Kulakov; D. A. Mishkinis; P. V. Bohan

2000-01-01

221

Analysis of solar aided heat pump systems with seasonal thermal energy storage in surface tanks  

Microsoft Academic Search

Annual periodic performance of a solar assisted ground-coupled heat pump space heating system with seasonal energy storage in a hemispherical surface tank is investigated using analytical and computational methods. The system investigated employs solar energy collection and dumping into a seasonal surface tank throughout the whole year with extraction of thermal energy from the tank for space heating during the

R. Yumruta?; M. Ünsal

2000-01-01

222

Latent heat thermal energy storage using cylindrical capsule: Numerical and experimental investigations  

Microsoft Academic Search

This paper is aimed at analyzing the melting behavior of paraffin wax as a phase change material (PCM) encapsulated in a cylindrical capsule, used in a latent heat thermal energy storage system with a solar water heating collector. The heat for melting of PCM in the capsule is provided by hot water surrounding it. Since it is observed experimentally that

A. Felix Regin; S. C. Solanki; J. S. Saini

2006-01-01

223

Multi-zone thermal energy storage variable air volume hydronic heat pump system  

Microsoft Academic Search

This patent describes a multi-zone thermal energy storage variable air volume heat pump system for capacity effective averaging in and selection of a multiplicity of continuously operable heat pumps that may vary in capacity and each operable at its optimum capacity and assigned to a separate zone space, and including: heat pumps comprising a refrigerant compressor with a reversing valve

Meckler

1988-01-01

224

Combined heat and mass transfer by natural convection in a saturated thermally stratified porous medium  

SciTech Connect

A numerical study is presented for the combined heat and mass transfer by natural convection adjacent to a vertical surface embedded in a stably thermally stratified, fluid-saturated, low-porosity medium. A wide range of thermal stratification levels is considered in flows with both aiding and opposing buoyant forces. The thermal stratification was shown to have a profound influence on the heat and mass transfer rates and on the direction of flow and transport. The underlying physical phenomena are explained while providing the Nusselt and Sherwood number data.

Angirasa, D.; Peterson, G.P. [Texas A and M Univ., College Station, TX (United States). Dept. of Mechanical Engineering; Pop, I. [Univ. of Cluj (Romania). Faculty of Mathematics

1997-02-21

225

Analytic approximate solutions for heat transfer of a micropolar fluid through a porous medium with radiation  

NASA Astrophysics Data System (ADS)

This paper aims to present complete analytic solution to heat transfer of a micropolar fluid through a porous medium with radiation. Homotopy analysis method (HAM) has been used to get accurate and complete analytic solution. The analytic solutions of the system of nonlinear ordinary differential equations are constructed in the series form. The convergence of the obtained series solutions is carefully analyzed. The velocity and temperature profiles are shown and the influence of coupling constant, permeability parameter and the radiation parameter on the heat transfer is discussed in detail. The validity of our solutions is verified by the numerical results (fourth-order Runge-Kutta method and shooting method).

Rashidi, M. M.; Mohimanian Pour, S. A.; Abbasbandy, S.

2011-04-01

226

Experimental evaluation of a simulation model for wrap-around heat exchanger, solar storage tanks  

SciTech Connect

The thermal performance of a commercially available 80 gallon, solar storage tank with an integral wrap-around heat exchanger is characterized experimentally an indoor test stand. The experimental results are used to evaluated the accuracy of a previously developed simulation model. Heat input on the collector side of the heat exchanger is held constant causing the heat transfer to reach a quasi-steady state. Temperatures in the heat exchanger and tank increase with time, however, the temperature differences across the heat exchanger remain nearly constant. Several combinations of heat input and collector loop flow are investigated. The development of the tank temperature profiles over time and the overall heat transfer performance predicted by the model are compared with experimental results. The influence of an electric auxiliary heater located in the top of the solar storage tank on the heat exchanger performance is investigated. Experimental normalization of the model is considered and modifications to the model and experiments are recommended.

Miller, J.A.; Hittle, D.C.

1995-05-01

227

Computational modeling of heat transfer over an unsteady stretching surface embedded in a porous medium  

Microsoft Academic Search

The present paper deals with the study of heat transfer characteristics in the laminar boundary layer flow of an incompressible\\u000a viscous fluid over an unsteady stretching sheet which is placed in a porous medium in the presence of viscous dissipation\\u000a and internal absorption or generation. Similarity transformations are used to convert the governing time dependent nonlinear\\u000a boundary layer equations into

Dulal Pal; P. S. Hiremath

2010-01-01

228

Characteristics of two-phase closed thermosiphons for medium temperature heat recovery applications  

Microsoft Academic Search

Application of two-phase closed thermosiphons to heat recovery systems has led the authors to investigate the performance of thermosiphons at medium temperatures. Two-phase closed thermosiphons working under various conditions have been tested and their thermal performance has been measured for mean evaporator wall temperatures between 100°C and 250°C. A description of the design and construction of the test facility is

Ioan Sauciuc; Aliakbar Akbarzadeh; Peter Johnson

1995-01-01

229

Maximum urban heat island intensity in a medium-sized coastal Mediterranean city  

Microsoft Academic Search

This paper studies the maximum intensity of the urban heat island (UHI) that develops in Volos urban area, a medium-sized\\u000a coastal city in central Greece. The maximum temperature difference between the city center and a suburb is 3.4°C and 3.1°C\\u000a during winter and summer, respectively, while during both seasons the average maximum UHI intensity is 2.0°C. The UHI usually\\u000a starts

Dimitris K. Papanastasiou; Constantinos Kittas

2011-01-01

230

Experimental investigation on performance of ice storage air-conditioning system with separate heat pipe  

SciTech Connect

An experimental study on operation performance of ice storage air-conditioning system with separate helical heat pipe is conducted in this paper. The experimental system of ice storage air-conditioning system with separate heat pipe is set up. The performance parameters such as the evaporation pressure and the condensation pressure of refrigeration system, the refrigeration capacity and the COP (coefficient of performance) of the system, the IPF (ice packing factor) and the cool storage capacity in the cool storage tank during charging period, and the cool discharge rate and the cool discharge capacity in the cool storage tank, the outlet water temperature in the cool storage tank and the outlet air temperature in room unit during discharging period are investigated. The experimental results show that the ice storage air-conditioning system with separate helical heat pipe can stably work during charging and discharging period. This indicates that the ice storage air-conditioning system with separate helical heat pipe is well adapted to cool storage air-conditioning systems in building. (author)

Fang, Guiyin; Liu, Xu; Wu, Shuangmao [Department of Physics, Nanjing University, Nanjing 210093 (China)

2009-11-15

231

Heat storing fireplace  

Microsoft Academic Search

The design of heat storing fireplace including a fire-box surrounded by a heat storage medium which is either an enclosure containing a material having a high specific heat such as sand or gravel or a large number of heat conducting bags containing a high specific heat material is given. Exhaust gases are conveyed from the fire-box to an exhaust outlet

Der M. R

1981-01-01

232

Modeling of fixed bed heat storage units utilizing phase change materials  

NASA Astrophysics Data System (ADS)

A computer model has been developed for the calculation of the heat exchanged and temperature profiles in a packed bed containing a phase change material. The packed bed is intended as a heat storage unit in which an inert fluid flowing through the bed exchanges heat with an encapsulated spherical shot of the phase change (melting and freezing) material. Examples of predicted bed temperature profiles during heat storage and utilization cycles are given. For A1-12 wt pct Si and Al-30 wt pct Si shot, a sequence of storage and utilization cycles with cyclic cocurrent fluid flow was found to utilize the high latent heat of fusion of the shot efficiently and permit the utilization of the bed as a near isothermal (577°C) heat recuperator.

Ananthanarayanan, V.; Sahai, Y.; Mobley, C. E.; Rapp, R. A.

1987-06-01

233

Properties optimization for phase-change energy storage in air-based solar heating systems  

Microsoft Academic Search

A parametric study has been conducted to determine the optimum physical properties of phase-change energy storage materials for solar air-heating systems. Simulation techniques are used to determine the system performance over the entire heating season. Variations of the solar fraction of the load with melting temperature, latent heat, load characteristics, and control strategy have been determined. Air-heating systems with a

J. J. Jurinak; S. I. Abdel-Khalik

1978-01-01

234

Closed Loop Chemical Systems for Energy Storage and Transmission (Chemical Heat Pipe). Final Report.  

National Technical Information Service (NTIS)

The work documents the anlaysis of closed loop chemical systems for energy storage and transmission, commonly referred to as the Chemical Heat Pipe (CHP). Among the various chemical reaction systems and sources investigated, the two best systems were dete...

H. B. Vakil J. W. Flock

1978-01-01

235

Candidate Thermal Energy Storage Technologies for Solar Industrial Process Heat Applications.  

National Technical Information Service (NTIS)

The successful application of solar industrial process heat (SIPH) will depend, in part, on the use of thermal energy storage (TES) to provide continuous operation during periods of solar isolation. A number of candidate TES system elements have been iden...

E. R. Furman

1979-01-01

236

Fundamental Heat-Transfer Processes Related to Phase-Change Thermal-Storage Media.  

National Technical Information Service (NTIS)

Research performed between June and December 1982 on fundamental heat transfer processes which occur in phase-change thermal storage systems is described. The research encompasses both freezing and melting, and includes both experiment and analysis. The e...

E. M. Sparrow

1982-01-01

237

Assessment of Plant Toxicity Threshold of Several Heat Transfer and Storage Fluids and Eutectic Salts.  

National Technical Information Service (NTIS)

Plant toxicity threshold levels of several heat transfer and storage fluids and eutectic salts were determined by using a modified Neubauer technique. Barley seed germination and seedling growth were used for the toxicity tests. The general order of toxic...

H. Nishita

1980-01-01

238

Selected issues related to heat storage tank modelling and optimisation aimed at forecasting its operation  

NASA Astrophysics Data System (ADS)

The paper presents results of research focused on modelling heat storage tank operation used for forecasting purposes. It presents selected issues related to mathematical modelling of heat storage tanks and related equipment and discusses solution process of the optimisation task. Presented detailed results were obtained during real-life industrial implementation of the optimisation process at the Siekierki combined heat and power (CHP) plant in Warsaw owned by Vattenfall Heat Poland S.A. (currently by Polish Oil & Gas Company - PGNiG SA) carried out by the Academic Research Centre of Power Industry and Environment Protection, Warsaw University of Technology in collaboration with Transition Technologies S.A. company.

Badyda, Krzysztof; Bujalski, Wojciech; Niewi?ski, Grzegorz; Warcho?, Micha?

2011-12-01

239

Performance analysis of a latent heat storage system with phase change material for new designed solar collectors in greenhouse heating  

SciTech Connect

The continuous increase in the level of greenhouse gas emissions and the rise in fuel prices are the main driving forces behind the efforts for more effectively utilize various sources of renewable energy. In many parts of the world, direct solar radiation is considered to be one of the most prospective sources of energy. In this study, the thermal performance of a phase change thermal storage unit is analyzed and discussed. The storage unit is a component of ten pieced solar air collectors heating system being developed for space heating of a greenhouse and charging of PCM. CaCl{sub 2}6H{sub 2}O was used as PCM in thermal energy storage with a melting temperature of 29 C. Hot air delivered by ten pieced solar air collector is passed through the PCM to charge the storage unit. The stored heat is utilized to heat ambient air before being admitted to a greenhouse. This study is based on experimental results of the PCM employed to analyze the transient thermal behavior of the storage unit during the charge and discharge periods. The proposed size of collectors integrated PCM provided about 18-23% of total daily thermal energy requirements of the greenhouse for 3-4 h, in comparison with the conventional heating device. (author)

Benli, Hueseyin [Department of Technical and Vocational Education, Firat University, TR-23119, Elazig (Turkey); Durmus, Aydin [Department of Mechanical Engineering, Ondokuz Mayis University, TR-55139, Samsun (Turkey)

2009-12-15

240

Heat storage in forest biomass significantly improves energy balance closure particularly during stable conditions  

NASA Astrophysics Data System (ADS)

Temperature measurements in trunks and branches in a mature ca. 100 years-old mixed pine and spruce forest in central Sweden were used to estimate the heat storage in the tree biomass. The estimated heat flux in the sample trees and data on biomass distributions were used to scale up to stand level biomass heat fluxes. The rate of change of sensible and latent heat storage in the air layer below the level of the flux measurements was estimated from air temperature and humidity profile measurements and soil heat flux was estimated from heat flux plates and soil temperature measurements. The fluxes of sensible and latent heat from the forest were measured with an eddy covariance system in a tower. The analysis was made for a two-month period in summer of 1995. The tree biomass heat flux was the largest of the estimated storage components and varied between 40 and -35 W m-2 on summer days with nice weather. Averaged over two months the diurnal maximum of total heat storage was 45 W m-2 and the minimum was -35 W m-2. The soil heat flux and the sensible heat storage in air were out of phase with the biomass flux and they reached maximum values that were about 75% of the maximum of the tree biomass heat storage. The energy balance closure improved significantly when the total heat storage was added to the turbulent fluxes. The slope of a regression line with sum of fluxes and storage as independent and net radiation as dependent variable, increased from 0.86 to 0.95 for half-hourly data and the scatter was also reduced. The most significant finding was, however, that during nights with strongly stable conditions when the sensible heat flux dropped to nearly zero, the total storage matched the net radiation nearly perfectly. Another interesting result was that the mean energy imbalance started to increase when the Richardson number became more negative than ca. -0.1. In fact, the largest energy deficit occurred at maximum instability. Our conclusion is that eddy covariance measurements can function well during stable conditions but that the functioning under strong instabilities might be a so far unforeseen problem.

Lindroth, A.; Mölder, M.; Lagergren, F.

2009-08-01

241

Cold Heat Storage Characteristics of O/W-type Latent Heat Emulsion Including Continuum Phase of Water Treated with a Freezing Point Depression  

NASA Astrophysics Data System (ADS)

This paper deals with flow and cold heat storage characteristics of the oil (tetradecane, C14H30, freezing point 278.9 K, Latent heat 229 kJ/kg)/water emulsion as a latent heat storage material having a low melting point. The test emulsion includes a water-urea solution as a continuum phase. The freezing point depression of the continuum phase permits enhancement of the heat transfer rate of the emulison, due to the large temperature difference between the latent heat storage material and water-urea solution. The velocity of emulsion flow and the inlet temperature of coolant in a coiled double tube heat exchanger are chosen as the experimental parameters. The pressure drop, the heat transfer coefficient of the emulsion in the coiled tube are measured in the temperture region over solid and liquid phase of the latent heat storage material. The finishing time of the cold heat storage is defined experimentally in the range of sensible and latent heat storage. It is clarified that the flow behavior of the emulsion as a non-Newtonian fluid has an important role in cold heat storage. The useful nondimentional correlation equations for the additional pressure loss coefficient, the heat transfer coefficient and the finishing time of the cold heat storage are derived in terms of Dean number and heat capacity ratio.

Inaba, Hideo; Morita, Shin-Ichi

242

Performance Enhancement of a PCM Cold Storage under Condition of Heat Flux  

Microsoft Academic Search

The objective of this work presents the numerical investigations of the enhancement performance of an phase change cold storage unit which is used for an air conditioning system during the solidification (discharge) process under the boundary condition of heat flux. The shell-and-tube cold storage unit is a typical tube-foil arrangement composed of an energy storage. The aluminum foils are arranged

Guo Chaxiu; Dong Hexin; Wei Xinli

2010-01-01

243

Effect of pH of the recovery medium on the apparent heat resistance of three strains of Bacillus cereus.  

PubMed

The influence of pH of the recovery medium, in the range 7.6-5.4, on the apparent heat resistance of three strains of Bacillus cereus (ATCC 4342, 7004 and 9818) has been investigated. The highest counts of heat-injured spores were obtained at pH near neutral, decreasing markedly as pH was reduced, especially with longer heating times. When the media were acidified, the apparent D-values tended to decrease, although some exceptions related to the strain and the nature of the medium were observed. z-Values determined were not affected by the pH of the medium. PMID:8880321

González, I; López, M; Mazas, M; Bernardo, A; Martín, R

1996-08-01

244

Thermal storage incentives take the heat off Texas utility  

SciTech Connect

The development of a thermal storage incentives program won first prize in the Company Program category of Edison Electric Institute's 1985 Energy Management and Writing Awards contest. It was submitted by Jeffrey B. Herring, transmission services consultant, Texas Utilities Generating Company, Dallas, TX. The energy storage incentives of the utility are described.

Not Available

1986-03-01

245

Comparison of Testing Methods for Latent-Heat-Storage Devices.  

National Technical Information Service (NTIS)

ASHRAE Standard 94-77, Method of Testing Thermal Storage Devices Based on Thermal Performance, was developed to allow manufacturers of thermal energy storage devices to compare their products in a meaningful way. When Standard 94-77 was used for thermal e...

R. L. Cole J. R. Hull Y. Lwin Y. S. Cha

1983-01-01

246

On the performance of air-based solar heating systems utilizing phase-change energy storage  

Microsoft Academic Search

Simulation techniques are used to examine the performance of air-based solar heating systems utilizing phase change energy storage (PCES). The effects of storage size, melting temperature, and latent heat on the thermal performance of the system are quantified for various load characteristics, collector types, and control strategies. The effect of semi-congruent melting of the phase-change material (PCM) on system performance

J. J. Jurinak; S. I. Abdel-Khalik

1979-01-01

247

An urban canyon energy budget model and its application to urban storage heat flux modeling  

Microsoft Academic Search

To obtain a local-scale urban energy balance by either measurement or modeling it is necessary to determine storage heat flux (?Qs). This flux cannot be measured directly due to the complexity of the urban surface. The Grimmond et al. Objective Hysteresis Model (OHM) [C.S.B. Grimmond, H.A. Cleugh, T.R. Oke, An objective urban heat storage model and its comparison with other

A. John Arnfield; C. S. B. Grimmond

1998-01-01

248

Thermal Storage by Latent Heat: A Viable Option for Energy Conservation in Buildings  

Microsoft Academic Search

Thermal storage by latent heat is an effective means of energy conservation in buildings; however, practical developments have been hampered by the lack of technically feasible storage materials. Organic materials that were first discarded as too costly could be attractive in new perspectives such as load shifting and peak demand reduction. The evolution of phase-change materials technology is reviewed, and

JEAN PARIS; MICHEL FALARDEAU; CÉCILE VILLENEUVE

1993-01-01

249

Solar cooking system with or without heat storage for families and institutions  

Microsoft Academic Search

A solar cooking system, with or without temporary heat storage, has been developed and installed in different countries of the world. The two basic system components are the solar collectors with reflectors and a cooking unit. When thermal storage is needed, a tank filled with pebbles is added to the system. The working fluid, usually a vegetable oil, circulates in

Klemens Schwarzer; Maria Eugênia Vieira da Silva

2003-01-01

250

Solar assisted absorption or motor driven heat pump with earth seasonal storage, part 1  

Microsoft Academic Search

A plant composed of an energy roof, a seasonal earth storage and an absorption heat pump has been tested. The purpose was to study the behavior of the various components and their interaction. The surveys went on during two years. The following operations are considered: the charging of the earth storage by the energy roof and the working of an

R. M. Lazzarin

1986-01-01

251

Thermal storage by latent heat; A viable option for energy conservation in buildings  

Microsoft Academic Search

Thermal storage by latent heat is an effective means of energy conservation in buildings; however, practical developments have been hampered by the lack of technically feasible storage materials. Organic materials that were first discarded as too costly could be attractive in new perspectives such as load shifting and peak demand reduction. In this paper, the evolution of phase-change materials technology

M. Falardeau; C. Villeneuve

2009-01-01

252

Eutectic mixtures of capric acid and lauric acid applied in building wallboards for heat energy storage  

Microsoft Academic Search

Capric acid (CA) and lauric acid (LA), as phase change materials (PCM), can be applied for energy storage in low temperature. The phase transition temperature and values of latent heat of eutectic mixtures of CA and LA are suitable for being incorporated with building materials to form phase change wallboards used for building energy storage. 120, 240 and 360 accelerated

Lv Shilei; Zhu Neng; Feng Guohui

2006-01-01

253

Integrated heat pipe-thermal storage design for a solar receiver. [Constant power source with heat from sun or from storage  

Microsoft Academic Search

Light-weight heat pipe wall elements that incorporate a thermal storage subassembly within the vapor space are being developed as part of the Organic Rankine Cycle Solar Dynamic Power Systems (ORC-SDPS) receiver for the space station application. The operating temperature of he heat pipe elements is in the 770 to 810°K range with a design power throughput of 4.8 kW per

E. S. Keddy; J. T. Sena; K. Woloshun; M. A. Merrigan; G. Heidenreich

1986-01-01

254

Dynamics of slow light and light storage in a Doppler-broadened electromagnetically-induced-transparency medium: A numerical approach  

NASA Astrophysics Data System (ADS)

We present a numerical scheme to study the dynamics of slow light and light storage in an electromagnetically-induced-transparency (EIT) medium at finite temperatures. Allowing for the motional coupling, we derive a set of coupled Schrödinger equations describing a boosted closed three-level EIT system according to the principle of Galilean relativity. The dynamics of a uniformly moving EIT medium can thus be determined by numerically integrating the coupled Schrödinger equations for atoms plus one ancillary Maxwell-Schrödinger equation for the probe pulse. The central idea of this work rests on the assumption that the loss of ground-state coherence at finite temperatures can be ascribed to the incoherent superposition of density matrices representing the EIT systems with various velocities. Close agreements are demonstrated in comparing the numerical results with the experimental data for both slow light and light storage. In particular, the distinct characters featuring the decay of ground-state coherence can be well verified for slow light and light storage. This warrants that the current scheme can be applied to determine the decaying profile of the ground-state coherence as well as the temperature of the EIT medium.

Su, Shih-Wei; Chen, Yi-Hsin; Gou, Shih-Chuan; Horng, Tzyy-Leng; Yu, Ite A.

2011-01-01

255

Refrigerating Equipment for Storage Compartments: Heat Load Calculation and Selection.  

National Technical Information Service (NTIS)

The refrigeration heat load for each refrigerated compartment shall be calculated for a pull-down condition, and also for a normal operating condition, and shall include the sum of the estimated transmission, infiltration, ventilation, and product heat lo...

1964-01-01

256

A thermally stable heating mechanism for the intracluster medium: turbulence, magnetic fields and plasma instabilities  

NASA Astrophysics Data System (ADS)

We consider the problem of self-regulated heating and cooling in galaxy clusters and the implications for cluster magnetic fields and turbulence. Viscous heating of a weakly collisional magnetized plasma is regulated by the pressure anisotropy with respect to the local direction of the magnetic field. The intracluster medium is a high-beta plasma, where pressure anisotropies caused by the turbulent stresses and the consequent local changes in the magnetic field will trigger very fast microscale instabilities. We argue that the net effect of these instabilities will be to pin the pressure anisotropies at a marginal level, controlled by the plasma beta parameter. This gives rise to local heating rates that turn out to be comparable to the radiative cooling rates. Furthermore, we show that a balance between this heating and bremsstrahlung cooling is thermally stable, unlike the often conjectured balance between cooling and thermal conduction. Given a sufficient (and probably self-regulating) supply of turbulent power, this provides a physical mechanism for mitigating cooling flows and preventing cluster core collapse. For observed density and temperature profiles, the assumed balance of viscous heating and radiative cooling allows us to predict magnetic field strengths, turbulent velocities and turbulence scales as functions of distance from the centre. Specific predictions and comparisons with observations are given for several different clusters. Our predictions can be further tested by future observations of cluster magnetic fields and turbulent velocities.

Kunz, M. W.; Schekochihin, A. A.; Cowley, S. C.; Binney, J. J.; Sanders, J. S.

2011-02-01

257

Role of heat transfer in the stabilization of the flame in a closed volume filled with high-porosity medium  

NASA Astrophysics Data System (ADS)

The results of modeling of the combustion of a gas-air mixture in a closed volume filled with high-porosity medium have been given. A comparison of the calculation results to experimental data has shown their qualitative agreement. It has been established that a quasistationary regime of propagation of the flame is possible in the case of fairly large relative length of the system and specific surface of the porous medium. Rapid deceleration of the flame is attributed to the decrease in the area of its surface because of the quenching on the reactor walls and the intense heat exchange between the hot combustion products and the porous medium. Stabilization of the flame propagation occurs when the heat release in gaseous combustion and the heat loss during the heat exchange between the combustion products and the porous medium are approximately equal.

Dobrego, K. V.; Kozlov, I. M.; Gnezdilov, N. N.; Shmelev, E. S.

2013-03-01

258

Heat Release Rates for Shipboard Dry Goods Storage Space Materials.  

National Technical Information Service (NTIS)

Compartment-scale tests were conducted to evaluate the fire performance of items found in typical dry goods storage spaces on DDG-51 class destroyers. Packaging materials included cardboard boxes, Kraft paper and polyethylene bubble wrap. Toilet paper, pa...

F. W. Williams H. Pham J. B. Hoover

2007-01-01

259

Physicochemical studies of porous materials for thermochemical storage of heat  

Microsoft Academic Search

The structure (texture) of an silicagel impregnated with MgCl 2 , CaCl 2 and SrCl 2 as well as the adsorption equilibrium of water against those confined salt hydrates and two different samples of zeolite A were investigated. This materials are potential candidates for (seasonal) thermochemical storage applications. Whereas the mesoporous silica based materials show a high storage capacity the

J. Jänchen; A. Grimm; H. Stach

260

Metal glass vacuum tube solar collectors are approaching lower-medium temperature heat application.  

PubMed

Solar thermal collectors are widely used worldwide mainly for hot water preparation at a low temperature (less than 80?C). Applications including many industrial processes and central air conditioning with absorption chillers, instead require lower-medium temperature heat (between 90 degrees C and 150 degrees C) to be driven when using solar thermal energy. The metal absorber glass vacuum tube collectors (MGVT) are developed for this type of applications. Current state-of-art and possible future technology development of MGVT are presented. PMID:20588568

Jiang, Xinian

2010-04-26

261

Metal glass vacuum tube solar collectors are approaching lower-medium temperature heat application.  

PubMed

Solar thermal collectors are widely used worldwide mainly for hot water preparation at a low temperature (less than 80 degrees C). Applications including many industrial processes and central air conditioning with absorption chillers, instead require lower-medium temperature heat (between 90 degrees C and 150 degrees C) to be driven when using solar thermal energy. The metal absorber glass vacuum tube collectors (MGVT) are developed for this type of applications. Current state-of-art and possible future technology development of MGVT are presented. PMID:20607893

Jiang, Xinian

2010-04-26

262

Solar energy storage via a closed-loop chemical heat pipe  

Microsoft Academic Search

The performance of a solar chemical heat pipe was studied using CO[sub 2] reforming of methane as the vehicle for storage and transport of solar energy. The endothermic reforming reaction was carried out with a reactor packed with a supported rhodium catalyst and heated by the concentrated solar flux from the Schaeffer solar furnace at the Weizmann Institute (Rehovot, Israel).

M. Levy; R. Levitan; H. Rosin; R. Rubin

1993-01-01

263

Effect of solar storage wall on the passive solar heating constructions  

Microsoft Academic Search

Three different greenhouse prototype designs: gable, flat and semi-circle roof shapes were investigated at the Faculty of Agriculture, Suez-Canal University, Egypt. Investigations were carried out to find out the effect of using the adobe (trombe) wall as solar heat storage used for greenhouse passives heating. The study was conducted under controllable weather conditions and outdoor under the prevailing weather conditions

A. A. Hassanain; E. M. Hokam; T. K. Mallick

2011-01-01

264

Solar collector heat exchanger or hot water storage tank and method of forming same  

Microsoft Academic Search

A solar collector, or absorber, panels or a heat storage tank, suitable for heating water using solar energy is formed from two sheets of uncured elastic material, such as EPDM rubber, by simultaneously bonding and curing the peripheral edges of the two sheets and at spaced apart, discrete areas over most of the interior areas of the sheets. In one

Buckley

1985-01-01

265

Study of the thermal behavior of a latent heat cold storage unit operating under frosting conditions  

Microsoft Academic Search

A study is performed of the thermal behavior of a latent heat cold storage unit operating under frosting conditions. This unit is employed to maintain the temperature inside the refrigerated compartment of a truck below 265 K. The system consists of parallel plates filled with a phase change material (PCM) that absorbs heat from the flow of warm moist air.

A. P. Simard; M. Lacroix

2003-01-01

266

Application of latent heat thermal energy storage in buildings: State-of-the-art and outlook  

Microsoft Academic Search

Latent heat thermal energy storage (LHTES) is becoming more and more attractive for space heating and cooling of buildings. The application of LHTES in buildings has the following advantages: (1) the ability to narrow the gap between the peak and off-peak loads of electricity demand; (2) the ability to save operative fees by shifting the electrical consumption from peak periods

Yinping Zhang; Guobing Zhou; Kunping Lin; Qunli Zhang; Hongfa Di

2007-01-01

267

Thermal energy storage in the ground: Comparative analysis of heat transfer modeling using U-tubes and boreholes  

Microsoft Academic Search

Large scale thermal energy storage for solar heating applications can be accomplished in the ground through the installation of an array of vertical heat exchange boreholes or U-tubes. Simulation modeling of the storage subsystem and its integration with the total system is essential for design and performance evaluation. Although U-tube storage design is especially attractive in clay soils and preferable

Dwayne S. Breger; James E. Hubbell; Hamid El Hasnaoui; J. Edward Sunderland

1996-01-01

268

The Development of Small Solar Concentrating Systems with Heat Storage for Rural Food Preparation  

NASA Astrophysics Data System (ADS)

A system, consisting of a parabolic reflector mounted on a polar axis tracker, has been designed and built. Air at atmospheric pressure is heated by the concentrated solar radiation to temperatures of up to 400°C as it is sucked through the receiver and into the pebble-bed heat storage unit, by means of a fan at the bottom of the storage. The stored heat is recovered by the reversal of the fan and the resulting hot air can be used in a convection oven and other appliances. This report discusses practical aspects, as well as preliminary test results, of such a system.

van den Heetkamp, R. R. J.

269

Latent heat storage in a fixed-bed packed with cross-linked polymer particles  

NASA Astrophysics Data System (ADS)

Experimental and numerical analyses were carried out to investigate the discharge characteristics of a fixed-bed, using form-stable cross-linked cylindrical polymer particles as a phase change type of heat storage material and ethylene glycol as heat transfer fluid. Firstly, particle-to-fluid heat transfer coefficient in a fixed-bed, essential for analyzing the discharge characteristics of the latent heat storage column, were evaluated experimentally using Schumann's extended theory, and an empirical formula for estimating the heat transfer coefficient was presented. Secondly, by using the empirical formula, the transient temperature distribution in the column and the transient response of the outlet temperature of the heat transfer fluid were calculated numerically, and the latter was compared with measurements of the outlet temperature of the fluid. The numerical results were found to be in good agreement with the experimental results.

Morita, Hiroki; Miyatake, Osamu

270

An integrated heat pipe-thermal storage design for a solar receiver  

NASA Astrophysics Data System (ADS)

Light-weight heat pipe wall elements that incorporate a thermal storage subassembly within the vapor space are being developed as part of the Organic Rankine Cycle Solar Dynamic Power System (ORC-SDPS) receiver for the Space Station application. The operating temperature of the heat pipe elements is in the 770 to 810 K range with a design power throughput of 4.8 kW per pipe. The total heat pipe length is 1.9 M. The Rankine cycle boiler heat transfer surfaces are positioned within the heat pipe vapor space, providing a relatively constant temperature input to the vaporizer. The heat pipe design employs axial arteries and distribution wicked thermal storage units with potassium as the working fluid. Performance predictions for this configuration have been conducted and the design characterized as a function of artery geometry, distribution wick thickness, porosity, pore size, and permeability.

Keddy, E.; Sena, J. T.; Woloshun, K.; Merrigan, M. A.; Heidenreich, G.

271

Heat capacity measurement of organic thermal energy storage materials  

Microsoft Academic Search

The heat capacities of tris(hydroxymethyl)aminomethane (TRIS), 2-amino-2-methyl-1,3-propanediol (AMPL), and neopentylglycol (NPG) are measured from (193.15 to 473.15)K by modulated differential scanning calorimetry (MDSC). The heat capacities of the low temperature layered or chain ordered phases, high temperature orientationally disordered phases, and the liquid phases are reported for these compounds. The low temperature heat capacities (193.15 to 280)K of AMPL are

Suresh Divi; Raja Chellappa; Dhanesh Chandra

2006-01-01

272

Selection of heat storage materials for ammonia–water and lithium bromide solar-powered absorption heat pump systems  

Microsoft Academic Search

A procedure for incorporating phase-change thermal storage materials in ammonia–water and lithium bromide absorption heat pumps systems is explored. Performance evaluation of the systems is presented and results are used as a guide in selecting appropriate phase-change materials (PCMs) for the absorption heat systems. Evaluation of the system indicates that there is a minimum generator temperature for each configuration of

S. N. Mumah

2008-01-01

273

Development of latent heat storage unit using form-stable high density polyethylene for solar total energy systems  

SciTech Connect

A latent heat storage unit using form-stable high density polyethylene (HDPE) for solar total energy systems is under development at Electrotechnical Laboratory. The present paper describes the progress of the development. To overcome the low thermal conductivity of HDPE, a direct contact latent heat storage using the HDPE rods and ethylene glycol as a heat transfer fluid was devised. Heat transfer experiments using 9 kg of HDPE showed excellent characteristics of latent heat storage. A prototype storage unit using 280 kg of HDPE was constructed and a series of charging and discharging experiments were performed.

Kamimoto, M.; Abe, Y.; Ozawa, T.; Sawata, S.; Tani, T.

1983-08-01

274

A Tool for Optimizing Unit Configuration of Heat Pump Water Heater System with a Storage Battery  

NASA Astrophysics Data System (ADS)

Heat pump water heaters (HPWHs) are one of the key technologies for reducing CO2 emissions from the household sector and must be downsized to expand their use in high density urban areas. Though the reduction of tank capacity is vital for downsizing HPWH, this often increases operation costs because it means heat pumps must boil water with expensive electricity during the day in order to avoid running out of hot water. Consequently, the development of a heat pump water heater with a storage battery (HPWH-SB) was investigated. In this paper, we develop an optimizing unit configuration tool that finds the optimal combination of heat pump, storage tank, and storage battery and estimate battery break-even point.

Tokoro, Ken-Ichi; Ikeya, Tomohiko; Mita, Yuuichi

275

Importance of salinity measurements in the heat storage estimation from TOPEX/POSEIDON  

NASA Astrophysics Data System (ADS)

Sea surface height anomalies from satellite altimeter data are used to estimate heat storage. Since variability in sea surface height is mostly due to expansion and contraction of the water column it can be correlated with variations in the heat and salt content. Therefore, estimation of heat storage from altimeter data, when compared to in situ estimates, requires corrections for the haline effect. Three sites with a nearly continuous time series of temperature and salinity profiles simultaneous with TOPEX/POSEIDON data are studied: HOT, CalCOFI and Hydrostation “S”. Haline corrections based on in situ and climatological salinity measurements are contrasted. For the studied regions, the haline corrections based on climatology provide equivalent or worse results than not applying a correction at all. The use of in situ salinity estimates decreased the differences between the heat storage estimates (up to 17 × 107 J m-2) and significantly improved their correlation (up to 0.18).

Sato, Olga T.; Polito, Paulo S.; Liu, W. Timothy

276

Occupational exposure in small and medium scale industry with specific reference to heat and noise.  

PubMed

This study was undertaken to assess heat and noise exposure and occupational safety practices in small and medium scale casting and forging units (SMEs) of Northern India. We conducted personal interviews of 350 male workers of these units through a comprehensive questionnaire and collected information on heat and noise exposure, use of protective equipment, sweat loss and water intake, working hour. The ambient wet bulb globe temperature (WBGT index) was measured using quest temp 34/36o area heat stress monitor. A-weighted Leq ambient noise was measured using a quest sound level meter "ANSI SI. 43-1997 (R 2002) type-1 model SOUNDPRO SE/DL". We also incorporated OSHA norms for hearing conservation which include - an exchange rate of 5dB(A), criterion level at 90dB(A), criterion time of eight hours, threshold level is equal to 80dB(A), upper limit is equal to 140dB(A) and with F/S response rate. Results of the study revealed that occupational heat exposure in melting, casting, forging and punching sections is high compared to ACGIH/NIOSH norms. Ambience noise in various sections like casting / molding, drop forging, cutting presses, punching, grinding and barreling process was found to be more than 90dB(A). About 95% of the workers suffered speech interference where as high noise annoyance was reported by only 20%. Overall, 68% workers were not using any personal protective equipment (PPE). The study concluded that the proportion of SME workers exposed to high level heat stress and noise (60 - 72 hrs/week) is high. The workers engaged in forging and grinding sections are more prone to noise induced hearing loss (NIHL) at higher frequencies as compared to workers of other sections. It is recommended that there is a strong need to implement the standard of working hours as well as heat stress and noise control measures. PMID:20160389

Singh, Lakhwinder Pal; Bhardwaj, Arvind; Deepak, Kishore Kumar

277

Scenario Development and Analysis of Hydrogen as a Large-Scale Energy Storage Medium (Presentation)  

SciTech Connect

The conclusions from this report are: (1) hydrogen has several important advantages over competing technologies, including - very high storage energy density (170 kWh/m{sup 3} vs. 2.4 for CAES and 0.7 for pumped hydro) which allows for potential economic viability of above-ground storage and relatively low environmental impact in comparison with other technologies; and (2) the major disadvantage of hydrogen energy storage is cost but research and deployment of electrolyzers and fuel cells may reduce cost significantly.

Steward, D. M.

2009-06-10

278

3D model for laser heating of a heterogeneous turbid medium  

NASA Astrophysics Data System (ADS)

In order to better understand the interaction of laser light with biological tissue, a light-transport model is integrated with a heat-transport model. The outputs include temperature as a function of position and time, given the illumination conditions and the optical and thermal properties of the tissue. The optical portion of the algorithm is based on the theory of radiative transfer through a turbid medium. Our computer program models multiple scattering in three dimensions using seven discrete irradiances which approximate the radiative transport equation. The distribution of absorbed light in the tissue is calculated and used as the source term in a discrete approximation to the thermal diffusion equation. Recently, we have been using the model to better understand the laser-heating of heterogeneous tissue. Rather than modeling a homogeneous mixture having properties given by weighted averages of those of tissue and blood, we model this medium as an array of blood vessels in a bloodless dermis background. We are currently analyzing temporal and spatial variations of temperature in homogeneous and heterogeneous tissue having identical blood concentrations. A particular application of the model is to the study of laser coagulation tonsillectomy.

Rossacci, Michael J.; Dimarzio, Charles A.; Lindberg, Scott C.; Pankratov, Michail M.

1997-05-01

279

A PILOT PROJECT FOR A LOW ENERGY BUILDING EQUIPPED WITH THERMAL SLABS, HEAT PUMP AND GROUND HEAT STORAGE  

Microsoft Academic Search

During the last years much interest has been paid to Low Temperature Systems, i.e. systems which use water to transfer the energy and have temperatures of this heating-cooling medium close to room temperature (20 °C for cooling, 26 °C for heating). Such systems show an overall energy consumption lower than for conventional air-conditioning systems and offer the possibility of using

F. Currò Dossi; M. De Carli; R. Del Bianco; F. Fellin; M. Tonon; R. Zecchin

280

Integrated heat pipe-thermal storage design for a solar receiver. [Constant power source with heat from sun or from storage  

SciTech Connect

Light-weight heat pipe wall elements that incorporate a thermal storage subassembly within the vapor space are being developed as part of the Organic Rankine Cycle Solar Dynamic Power Systems (ORC-SDPS) receiver for the space station application. The operating temperature of he heat pipe elements is in the 770 to 810/sup 0/K range with a design power throughput of 4.8 kW per pipe. The total heat pipe length is 1.9 M. The Rankine cycle boiler heat transfer surfaces are positioned within the heat pipe vapor space, providing a relatively constant temperature input to the vaporizer. The heat pipe design employs axial arteries and distribution wicked thermal storage units with potassium as the working fluid. Stainless steel is used as the containment tube and screen material. Performance predictions for this configuration have been conducted and the design characterized as a function of artery geometry, distribution wick thickness, porosity, pore size, and permeability. Details of the analysis and of fabrication and assembly procedures are presented. 2 refs., 8 figs.

Keddy, E.S.; Sena, J.T.; Woloshun, K.; Merrigan, M.A.; Heidenreich, G.

1986-01-01

281

Effects of the heat transfer fluid velocity on the storage characteristics of a cylindrical latent heat energy storage system: a numerical study  

NASA Astrophysics Data System (ADS)

A numerical study of the effects of the thermal fluid velocity on the storage characteristics of a cylindrical latent heat energy storage system (LHESS) was conducted. Due to the low thermal conductivity of phase change materials (PCMs) used in LHESS, fins were added to the system to increase the rate of heat transfer and charging. Finite elements were used to implement the developed numerical method needed to study and solve for the phase change heat transfer (melting of PCM) encountered in a LHESS during charging. The effective heat capacity method was applied in order to account for the large amount of latent energy stored during melting of the PCM and the moving interface between the solid and liquid phases. The effects of the heat transfer fluid (HTF) velocity on the melting rate of the PCM were studied for configurations having between 0 and 18 fins. Results show that the overall heat transfer rate to the PCM increases with an increase in the HTF velocity. However, the effect of the HTF velocity was observed to be small in configurations having very few fins, owing to the large residual thermal resistance offered by the PCM. However, the effect of the HTF velocity becomes more pronounced with addition of fins; since the thermal resistance on the PCM side of the LHESS is significantly reduce by the large number of fins in the system.

Ogoh, Wilson; Groulx, Dominic

2012-03-01

282

Thermal energy storage heat exchanger: molten salt heat exchanger design for utility power plants. Final report, July 1976July 1977  

Microsoft Academic Search

The use of thermal energy storage (TES) in the latent heat of molten salts as a means of conserving fossil fuels and lowering the cost of electric power was evaluated. Public utility systems provided electric power on demand. This demand is generally maximum during late weekday afternoons, with considerably lower overnight and weekend loads. Typically, the average demand is only

A. Ferarra; G. Yenetchi; R. Haslett; R. Kosson

1977-01-01

283

Study on performance of a packed bed latent heat thermal energy storage unit integrated with solar water heating system  

Microsoft Academic Search

In thermal systems such as solar thermal and waste heat recovery systems, the available energy supply does not usually coincide in time with the process demand. Hence some form of thermal energy storage (TES) is necessary for the most effective utilization of the energy source. This study deals with the experimental evaluation of thermal performance of a packed bed latent

284

Numerical heat transfer analysis of the packed bed latent heat storage system based on an effective packed bed model  

Microsoft Academic Search

Due to the complexity of the fluid flow and heat transfer in packed bed latent thermal energy storage (LTES) systems, many hypotheses were introduced into the previous packed bed models, which consequently influenced the accuracy and authenticity of the numerical calculation. An effective packed bed model was therefore developed, which could investigate the flow field as the fluid flows through

L. Xia; P. Zhang; R. Z. Wang

2010-01-01

285

Examinations on the Meteorologic Factors of Urban Heat Island Development in Small and Medium-sized Towns of Hungary  

Microsoft Academic Search

EXAMINATIONS ON THE METEOROLOGICAL FACTORS OF URBAN HEAT ISLAND DEVELOPMENT IN SMALL AND MEDIUM-SIZED TOWNS OF HUNGARY Sandor Szegedi, Renata Gyarmati, Laszlo Kapocska and Tamas Toth University of Debrecen Department of Meteorology, 4032 Debrecen Egyetem tér 1. The thermal difference between the settlements and their environment is called urban heat island (UHI). Potential UHI intensities are mainly determined by the

S. Szegedi; R. Gyarmati; L. Kapocska; T. Toth

2010-01-01

286

Flow and heat transfer of a fluid through a porous medium over a stretching surface with internal heat generation\\/absorption and suction\\/blowing  

Microsoft Academic Search

Fluid flow and heat-transfer in a porous medium over a stretching surface have been investigated. The flow is influenced by linearly stretching the surface with internal heat generation or absorption and by the presence of suction, blowing and impermeability of the surface. An analytical solution for this flow is utilized and two cases are studied, namely, (i) constant surface temperature

Rafael Cortell

2005-01-01

287

Two-tank working gas storage system for heat engine  

Microsoft Academic Search

This patent describes a working gas control system for use in connection with a hot gas engine including a power controller for admitting the working gas to the engine to increase engine power and for releasing working gas from the engine to decrease engine power. A compressor compresses the working gas released from the engine. Storage vessels are included for

Hindes

1987-01-01

288

Plasmonic random media based on gold nanorods as an optical storage medium  

Microsoft Academic Search

In this paper, we present our recent study on the plasmonic random media based on gold nanorods doped in polymer matrix using image correlation spectroscopy for noise-free multidimensional optical recording medium.

James W. M. Chon; Adam B. Taylor; Timothy Chow

2011-01-01

289

Results on the characterization of gas hydrate formation in a direct contact heat pump cool storage system  

Microsoft Academic Search

This report describes an investigation of a latent cool storage system which employs a refrigerant gas hydrate as the storage medium. A refrigerant gas hydrate is a compound consisting of a refrigerant gas molecule contained within a crystalline water molecule cage. In this system, the storage component is incorporated directly into the refrigeration cycle, replacing the conventional evaporator. The refrigerant

M. P. Ternes

1985-01-01

290

SCR self-supplied gate driver for medium-voltage application with capacitor as storage element  

Microsoft Academic Search

The resent increase in the application of medium-voltage variable-frequency drives and solid-state starters to AC motors has revived the idea of the SCR self-supplied gate driver (SSGD). This solution eliminates the need for an isolated power supply board or auxiliary power supply, with substantial savings in cost and space in medium-voltage applications. In this paper, the objective has been to

Dusan M. Raonic

2000-01-01

291

Combined heat and mass transfer by hydromagnetic natural convection over a cone embedded in a non-Darcian porous medium with heat generation\\/absorption effects  

Microsoft Academic Search

The problem of combined heat and mass transfer by natural convection over a permeable cone embedded in a uniform porous medium\\u000a in the presence of an external magnetic field and internal heat generation or absorption effects is formulated. The cone surface\\u000a is maintained at either constant temperature and constant concentration or uniform heat and mass fluxes. In addition, the\\u000a cone

Ali J. Chamkha; Mir Mujtaba A. Quadri

2002-01-01

292

Advanced high-temperature molten-salt storage research  

Microsoft Academic Search

We are researching advanced high-temperature molten-salt thermal storage for use in direct absorption receiver and thermal storage (DARTS) solar thermal systems. A molten salt at 900°C or higher is both the receiver heat transfer medium and the storage medium; a unique insulated platform (raft) separates the hot and cold medium in the thermocline thermal storage. We have measured raft performance

R. J. Copeland; R. T. Coyle

1983-01-01

293

The heating efficency of medium- and large-scale field-aligned currents at auroral latitudes  

NASA Astrophysics Data System (ADS)

Field-aligned currents (FACs) are an important mechanism for transporting energy and momentum from the solar wind into the upper atmosphere at high latitudes. The efficiency of energy dissipation depends on the ionospheric conductivity and the transverse scale size of the field-aligned current circuits. According to Vogt (2002) the conversion of electric current into heat should be most effective for scales of the order of some 10 km when typical ionospheric conductivities are considered. In order to test this conclusion we have performed a statistical analysis with FACs of various scale sizes. This study is based on observations that are derived from CHAMP magnetic field measurements taken during the years 2002-2005. FAC densities within the medium-scale wavelength band of 15-150 km and large-scale FACs (>150 km) are considered separately and their distributions are compared. The thermospheric mass density recorded simultaneously by CHAMP is used as a measure for the heat deposited in the ionospheric E-layer. The relation between current strength of the two FAC types and thermospheric heating is determined in a superposed epoch analysis. The analysis is performed separately for each season and covers all local time sectors.

Ritter, Patricia; Luehr, Hermann; Rentz, Stefanie

294

Thermal energy storage for building heating and cooling applications. Technical progress report, April 1979-March 1980  

SciTech Connect

The ORNL program in Thermal Energy Storage (TES) over the past year is reported. The ORNL effort constitutes one element in the Energy Storage Systems Division of the Department of Energy program to develop TES systems to facilitate conservation and the use of renewable sources. The program consists of developing sensible and latent heat technologies to meet the single goal of reduction in oil and gas consumption for residential and space conditioning. Three specific application elements were addressed: utility load management, solar energy applications, and conservation. Programs (both completed and ongoing) are summarized, and their relationship to the specific implementation plan are given. Ten final reports of subcontracts were issued over the year. In addition, five final reports are infinal review stage. The program completed a transition from low-temperature storage development including seasonal storage in natural aquifers to TES development for building heating and cooling applications.

Martin, J.F.; Hoffman, H.W.

1980-06-01

295

Short-term storage of canine preantral ovarian follicles using a powdered coconut water (ACP)-based medium.  

PubMed

The objective was to investigate the use of powdered coconut water (ACP)-based medium for short-term preservation of canine preantral follicles. Pairs of ovaries from mongrel bitches (n=9) were divided into fragments. One ovarian fragment, treated as a fresh control, was immediately fixed for histological analysis, whereas the other six ovarian fragments were stored either in phosphate-buffered saline (PBS; control group) or ACP medium in isothermal Styrofoam boxes containing biological ice packs. The boxes were sealed and opened only after 12, 24, or 36h. After opening each box, the ovarian fragments were submitted to histological analysis. In total, 12,302 preantral follicles were evaluated, with 64.5% primordial, 33.3% primary, and 2.3% secondary follicles. There were multiple oocytes in 1.3% of the follicles analyzed. At 24h, ACP was more efficient in preserving follicular morphology than PBS (P<0.05). Compared with the fresh control group, a significant reduction in the percentage of morphologically normal ovarian follicles was observed for PBS, starting at 24h; however, the decline started only at 36h for the ACP medium. During the experiment, the temperature inside the isothermal boxes increased from 3 to 9 degrees C (P<0.05), despite a constant room temperature. In conclusion, powdered coconut water (ACP) was an appropriate medium for short-term storage of canine preantral ovarian follicles. PMID:20207405

Lima, G L; Costa, L L M; Cavalcanti, D M L P; Rodrigues, C M F; Freire, F A M; Fontenele-Neto, J D; Silva, A R

2010-03-06

296

Thermal energy storage development for solar electrical power and process heat applications  

NASA Astrophysics Data System (ADS)

Development of thermal energy storage technologies for solar thermal systems has been conducted since the mid-1970s. This paper presents an overview of past and present experimental activities for electrical power and process heat applications both within and outside the United States. The factors affecting the selection of a storage technology for these applications, as well as the nature of those applications, are discussed. Future research needs are also described.

Radosevich, L. G.; Wyman, C. E.

1983-05-01

297

Analytical approximation for solidification processes in PCM storage with internal fins: imposed heat flux  

Microsoft Academic Search

Uses of thermal energy storage systems have expanded notably in recent decades. In thermal energy systems, internal heat transfer\\u000a enhancement techniques such as fins are often used because of the low thermal conductivity of the phase change materials (PCMs).\\u000a In this paper, solidification of a PCM is studied in a rectangular storage with horizontal internal plate fins and an imposed

F. Talati; A. H. Mosaffa; M. A. Rosen

2011-01-01

298

Performance of direct contact latent heat storage units with two hydrated salts  

SciTech Connect

The performance of a direct contact latent heat storage unit, that consists of two columns with different hydrated salts, has been investigated. Na[sub 2]CO[sub 3]-10H[sub 2]O (sodium carbonate decahydrate) and Na[sub 2]S[sub 2]O[sub 3][center dot]5H[sub 2]O (sodium thiosulphate pentahydrate) were contained in separate columns both having an inside diameter and total length of 0.184 m and 1.0 m, respectively. During heat charge, the hot keresone as a heat transfer fluid was bubbled through the sodium thiosulfate solution first. The partially cooled kerosene was then pumped to the second column containing the sodium thiosulfate solution first. The partially cooled kerosene was then pumped to the second column containing the sodium carbonate solution, discharging most of its heat content. Flow direction was reversed during heat discharge. The continuous phase temperature in the two columns, as well as kerosene inlet and outlet temperatures, were measured continuously. Results showed significant improvement in heat transfer rates by using two separate columns containing similar or different salts. The use of a combination of two different salts, having different crystallization temperatures, and contained in different columns connected in series, may provide better means of heat storage by allowing the system to operate as a phase change storage for longer periods of operation. This is particularly suitable for solar energy applications in which the collector temperature may vary significantly during the day.

Farid, M.M. (Jordan Univ. of Science and Technology, Irbid (Jordan)); Khalaf, A.N. (Univ. of Basrah (Iraq))

1994-02-01

299

Bacteriorhodopsin oriented in polyvinyl alcohol films as an erasable optical storage medium  

Microsoft Academic Search

Films of oriented bacteriorhodopsin have been formed in polyvinyl alcohol with excellent optical quality. Images with high contrast have been impressed and erased on these films. Second-harmonic microscopy has been used to read the image on a bacteriorhodopsin-polyvinyl alcohol film without erasure. The potential of these films for molecular information storage and computation is discussed.

Zhongping Chen; Hiroyuki Takei; Aaron Lewis; Isaiah Nebenzahl

1991-01-01

300

A study on cooling characteristics of clathrate compound as low temperature latent heat storage material  

NASA Astrophysics Data System (ADS)

Materials that can store low temperature latent heat are organic/inorganic chemicals, eutectic salt system and clathrate compound. Clathrate compound is the material that host compound in hydrogen bond forms cage and guest compound is included into it and combined. Crystallization of hydrate is generated at higher temperature than that of ice from pure water. And physical properties according to temperature are stable and congruent melting phenomenon is occurred without phase separation and it has relatively high latent heat. But clathrate compound still has supercooling problem occurred in the course of phase change and supercooling should be minimized because it affects efficiency of equipment very much. Therefore, various studies on additives to restrain this or heat storage methods are needed. Supercooling is the phenomenon that low temperature thermal storage material is not crystallized and existed as liquid for some time under phase change temperature. Because phase change into solid is delayed and it is existed as liquid due to this, heat transfer from low temperature thermal storage material is lowered. Therefore it is not crystallized at original phase change temperature and crystallized after cooled as much as supercooling degree and operation time of refrigerator is increased. In this study was investigated the cooling characteristics of the clathrate compound as a low temperature latent heat storage material. And additive was added to clathrate compound and its supercooling restrain effect was studied experimentally.

Kim, Chang Oh; Kim, Jin Heung; Chung, Nak Kyu

2007-10-01

301

Storing Industrial Waste Heat into an Oil Rock Cavern Storage.  

National Technical Information Service (NTIS)

Oulu energy works generates electricity and heat in a peat fired cogeneration power plant. The electricity is also generated by hydro power and the rest of demand is covered by commercial electricity from the state network. Furthermore there are peak boil...

K. Sipilae

1989-01-01

302

High heat-load absorbers for the APS storage ring  

SciTech Connect

The power density of the dipole x-rays in the 7-GeV APS storage ring is 261 watts/mrad at 300 mA of beam current. An array of absorbers is used in the ring to shield its vacuum chambers and diagnostics components in the path of these intense x-rays. This paper describes some of the unique absorber designs that were developed to handle the requirements of high power density and UHV compatibility with no water-to-vacuum joints.

Sharma, S.; Rotela, E.; Barcikowski, A.

2000-07-21

303

Primary Culture of Mycobacterium ulcerans from Human Tissue Specimens after Storage in Semisolid Transport Medium  

Microsoft Academic Search

Tissue specimens collected from patients with clinically suspected Buruli ulcer treated in two Buruli ulcer treatment centers in Benin between 1998 and 2004 were placed in semisolid transport medium and transported at ambient temperature for microbiological analysis at the Institute of Tropical Medicine in Antwerp, Belgium. The impact of the delay before microbiological analysis on primary culture of Mycobacterium ulcerans

Miriam Eddyani; Martine Debacker; Anandi Martin; Julia Aguiar; Christian R. Johnson; Cecile Uwizeye; Krista Fissette; Francoise Portaels

2008-01-01

304

Shallow heat injection and storage experiment monitored with electrical resistivity tomography and simulated with heat transport model  

NASA Astrophysics Data System (ADS)

Groundwater resources are increasingly used around the world as geothermal systems. Understanding physical processes and quantification of parameters determining heat transport in porous media is therefore important. To monitor the geothermal behavior of groundwater systems and to estimate the governing parameters, we rely mainly on borehole observations of the temperature field at a few locations (temperature logs or thermal response test). In analogy to research in hydrogeophysics, geophysical methods may be useful in order to yield additional information for thermal properties estimation with greater coverage than conventional wells. We report a heat transport study during a shallow heat injection and storage field test. Heated water (temperature of 50°C) was injected for 6 days at the rate of 80 l/h in a 10.5°C aquifer. Since bulk electrical resistivity variations can bring important information on temperature changes in aquifers (water electrical conductivity increases about 2%/°C around 25°C), we monitored the test with surface electrical resistivity tomography and we demonstrate its ability to monitor spatially the temperature variation. Time-lapse electrical imaging clearly shows the successive decrease and increase in bulk electrical resistivity of the plume of heated water, during the injection and the storage phase respectively. This information enabled to calibrate the conceptual flow and heat model used to simulate the test (using SEAWAT). Inverted resistivity values are validated with borehole electromagnetic measurements (EM39) and are in agreement with the temperature logs used to calibrate the parameters of the thermo-hydrogeological model. This field work demonstrates that surface electrical resistivity tomography can monitor heat and storage experiments in shallow aquifers. These results could potentially lead to a number of practical applications, such as the monitoring or the design of shallow geothermal systems. Moreover, sensitivity analyses and collinear diagnostic were used to assess the pertinence of the flow and heat model parameters. The most sensitive parameter is the thermal conductivity of the solid followed by the porosity, heat capacity of the solid and the longitudinal dispersivity. This indicates the predominance of conductive transport during the storage phase over the convective transport during the injection phase. These values rely only on temperature logs and more parameters could be derived or more robust values could be achieved with the use of geophysical data in a coupled inversion scheme.

Hermans, T.; Daoudi, M.; Vandenbohede, A.; Lebbe, L.; Nguyen, F. H.

2011-12-01

305

Reduction of chilling injury in the sweet persimmon `Fuyu' during storage by dry air heat treatments  

Microsoft Academic Search

Sweet persimmon fruit (Diospyros kaki cv. Fuyu L.) were heat-treated with dry air at 34–50°C for durations of 0.5–10 h, cooled immediately, and stored for 6.5 weeks at 0°C in air. After storage, fruit were held for 3 days at 20°C, and evaluated for quality. Extreme chilling injury (flesh gelling) was observed in non-heated fruit. Associated with development of chilling

Allan B Woolf; Sarah Ball; Karen J Spooner; Michael Lay-Yee; Ian B Ferguson; Christopher B Watkins; Anne Gunson; Shelley K Forbes

1997-01-01

306

Design and analysis of heat exchangers for high pressure metal hydride hydrogen storage  

Microsoft Academic Search

This study explores the development of a hydrogen storage system using high-pressure metal hydride, Ti1.1CrMn. When absorbing hydrogen (filling), the metal hydride releases large amounts of heat causing the hydride temperature to rise. The reaction rate depends on the metal hydride temperature, decreasing significantly if the heat is not removed quickly. To store 5 kg hydrogen needed to drive 300

Milan K Visaria

2011-01-01

307

Numerical simulation of a shell-and-tube latent heat thermal energy storage unit  

Microsoft Academic Search

A theoretical model was developed to predict the transient behavior of a shell-and-tube storage unit with the phase change material (PCM) on the shell side and the heat transfer fluid (HTF) circulating inside the tubes. The multidimensional phase change problem is tackled with an enthalpy-based method coupled to the convective heat transfer from the HTF. The numerical predictions are validated

M Lacroix

1993-01-01

308

Mixed-method pre-cooling reduces physiological demand without improving performance of medium-fast bowling in the heat  

Microsoft Academic Search

This study examined physiological and performance effects of pre-cooling on medium-fast bowling in the heat. Ten, medium-fast bowlers completed two randomised trials involving either cooling (mixed-methods) or control (no cooling) interventions before a 6-over bowling spell in 31.9±2.1°C and 63.5±9.3% relative humidity. Measures included bowling performance (ball speed, accuracy and run-up speeds), physical characteristics (global positioning system monitoring and counter-movement

Geoffrey M. Minett; Rob Duffield; Aaron Kellett; Marc Portus

2012-01-01

309

Artificial fertilisation in a terrestrial toadlet (Pseudophryne guentheri): effect of medium osmolality, sperm concentration and gamete storage.  

PubMed

Anurans exhibit a greater reproductive diversity than any other vertebrate order. However, studies investigating the effects of the external fertilisation environment on fertilisation success are limited to aquatic-breeding species. This study investigated the effects of fertilisation medium osmolality, sperm concentration and short-term oocyte storage on fertilisation success in a terrestrial-breeding anuran, Pseudophryne guentheri. Split-clutch experimental designs were used to determine optimal fertilisation conditions. To determine the effect of short-term sperm storage, sperm viability was assessed using fluorescence microscopy and percentage sperm motility and velocity quantified with a computer-assisted sperm analysis system. Fertilisation success was highest in media ranging in osmolality from 25mOsmkg(-1) to 100mOsmkg(-1), representing a broader range and higher optimal osmolality than previously reported for aquatic breeders. High rates of fertilisation (>75%) were achieved in relatively low sperm concentrations (2.5×10(4)mL(-1)). Oocytes stored in isotonic solutions (200mOsmkg(-1)) retained fertilisation capacity (32%) after 8h of storage, while sperm suspensions maintained motility (?26%) for 13 days. Additional studies on terrestrial-breeding anurans will be required to ascertain whether the optimal fertilisation conditions reported reflect adaptations to achieve fertilisation in a terrestrial environment. PMID:23174151

Silla, Aimee J

2013-10-01

310

Measurement of Latent Heat of Melting of Thermal Storage Materials for Dynamic Type Ice Thermal Storage  

NASA Astrophysics Data System (ADS)

In order to measure the latent heat of melting of ice slurries with various solute concentrations, an adiabatic calorimeter was constructed. Ice slurries were made from each aqueous solution of ethanol, ethylene glycol and silane coupling agent. The latent heat of melting of ice made from tap water was measured with the present calorimeter and the uncertainty of the result was one percent. Ice slurries were made both by mixing ice particles made from water with each aqueous solution and by freezing each aqueous solution with stirring in a vessel. The latent heat of melting of these ice slurries was measured with various concentrations of solution. The latent heat of melting decreased as the solute concentration or the freezing point depression increased. The latent heat of ice slurries made from ethanol or ethylene glycol aqueous solution agreed with that of ice made from pure water known already. The latent heat of melting of ice slurries made from silane coupling agent aqueous solution got smaller than that of ice made from pure water as the freezing point depression increased.

Sawada, Hisashi; Okada, Masashi; Nakagawa, Shinji

311

The Extended Fe Distribution in the Intracluster Medium and the Implications Regarding AGN Heating  

NASA Astrophysics Data System (ADS)

We present a systematic analysis of XMM-Newton observations of eight cool-core clusters of galaxies and determine the Fe distribution in the intracluster medium relative to the stellar distribution in the central dominant galaxy (CDG). Our analysis shows that the Fe is significantly more extended than the stellar mass in the CDG in all of the clusters in our sample, with a slight trend of increasing extent with increasing central cooling time. The excess Fe within the central 100 kpc in these clusters can be produced by Type Ia supernovae from the CDG over the past 3-7 Gyr. Since the excess Fe primarily originates from the CDG, it is a useful probe for determining the motion of the gas and the mechanical energy deposited by AGN outbursts over the past ~5 Gyr in the centers of clusters. We explore two possible mechanisms for producing the greater extent of the Fe relative to the stars in the CDG, bulk expansion of the gas and turbulent diffusion of the Fe. Assuming that the gas and Fe expand together, we find that a total energy of 1060-1061 erg s-1 must have been deposited into the central 100 kpc of these clusters in order to produce the currently observed Fe distributions. Since the required enrichment time for the excess Fe is approximately 5 Gyr in these clusters, this gives an average AGN mechanical power over this time of 1043-1044 erg s-1. The extended Fe distribution in cluster cores can also arise from turbulent diffusion. Assuming a steady state (i.e., the outward mass flux of Fe across a given surface is equal to the mass injection rate of Fe within that surface), we find that diffusion coefficients of 1029-1030 cm2 s-1 are required in order to maintain the currently observed Fe profiles. We find that heating by both turbulent diffusion of entropy and dissipation are important heating mechanisms in cluster cores. In half of the clusters with central cooling times greater than 1 Gyr, we find that heating by turbulent diffusion of entropy alone can balance radiative losses. In the remaining clusters, some additional heating by turbulent dissipation, with turbulent velocities of 150-300 km s-1, is required in order to balance radiative cooling. We also find that the average Type Ia supernova fraction within the central 100 kpc of these clusters is 0.53 (roughly twice the solar value), on the basis of the Si-to-Fe mass ratio. This implies a total (Type Ia plus core-collapse) supernova heating rate of less than 10% of the bolometric X-ray luminosity within the centers of clusters.

David, Laurence P.; Nulsen, Paul E. J.

2008-12-01

312

Study on performance of a packed bed latent heat thermal energy storage unit integrated with solar water heating system  

Microsoft Academic Search

In thermal systems such as solar thermal and waste heat recovery systems, the available energy supply does not usually coincide\\u000a in time with the process demand. Hence some form of thermal energy storage (TES) is necessary for the most effective utilization\\u000a of the energy source. This study deals with the experimental evaluation of thermal performance of a packed bed latent

N. Nallusamy; S. Sampath; R. Velraj

2006-01-01

313

Thermal radiation heat transfer effects on solidification of finite concentric cylindrical medium-enthalpy model and P-1 approximation  

NASA Astrophysics Data System (ADS)

In the present study of the solidification effect of thermal radiation on an absorbing, emitting, and isotropically scattering semitransparent gray medium that is bounded between two concentric cylinders, the conservation of energy is coupled with a set of moment equations derived from the radiative-transfer equation and Marshak-type boundary conditions through the application of the P-1 differential approximation. The use of the Gauss-Seidel iterative numerical scheme for an optically thick medium then yields the transient temperature distribution, the semitransparent phase-charge medium interface location, and the local axial and radiative heat fluxes.

Kim, Kwang S.; Yimer, Bedru

314

DESIGN OF CENTRAL SOLAR HEATING WITH UNDERGROUND SEASONAL STORAGE IN AUSTRALIA  

Microsoft Academic Search

The simulation of the central solar heating system with seasonal storage has done by using TRNSYS to predict thermal performances and economic aspects. The location of the simulated site is at Glenroy, Melbourne, a southern part of Australia (latitude: 37º 42´ S, longitude: 144º 5´ E, altitude: 97 m.). The meteorological conditions data are prepared by Meteonorm, based on 10

N. Chotivisarut; T. Kiatsiriroat; L. Aye

315

Leafy vegetable extracts—antioxidant activity and effect on storage stability of heated oils  

Microsoft Academic Search

The investigation was undertaken with an objective of analyzing the antioxidant capacity of leafy vegetables (LV) and testing their efficacy on storage of heated oils. Four leafy vegetables viz., cabbage (Brassica oleracea var. capitata), coriander leaves (Coriandrum sativum), hongone (Alternanthera sessilis), and spinach (Spinacia oleracea) were analyzed for antioxidant activity by standard methods. The ethanol extracts of LV were added

B. N. Shyamala; Sheetal Gupta; A. Jyothi Lakshmi; Jamuna Prakash

2005-01-01

316

Assessment of plant toxicity threshold of several heat transfer and storage fluids and eutectic salts  

Microsoft Academic Search

Plant toxicity threshold levels of several heat transfer and storage fluids and eutectic salts were determined by using a modified Neubauer technique. Barley seed germination and seedling growth were used for the toxicity tests. The general order of toxicity of the fluids applied to three mineral soils was ethylene gloycol > Dow 200 much greater than Caloria HT43 > Therminol

Nishita

1980-01-01

317

Recuperative heat exchangers in compressed-air energy storage plants. Final report  

Microsoft Academic Search

The purpose of this investigation was to develop a procurement specification for recuperative heat exchangers in Compressed Air Energy Storage Applications. Potential problem areas were identified and designs, operational guidelines, and a procurement specification were developed to minimize these problems. Interviews were conducted at existing recuperative gas turbine installations to identify the existing experience with recuperators. Thermal stress cracking, low

H. Lukas; M. E. Montgomery

1985-01-01

318

Role of the Heat Storage Well Future U.S. Energy Systems.  

National Technical Information Service (NTIS)

The Heat Storage Well system concept is found to have the potential to decrease U.S. energy consumption 10 to 15 percent while substantially reducing water and air pollution. Energy to be conserved is principally that now wasted in generating electricity ...

C. F. Meyer W. Hausz B. L. Ayres H. M. Ingram

1976-01-01

319

Analysis of Fluid Flow and Heat Transfer in a Liquid Hydrogen Storage Vessel for Space Applications  

Microsoft Academic Search

This paper presents a systematic analysis of fluid flow and heat transfer in a liquid hydrogen storage vessel for both earth and space applications. The study considered a cylindrical tank with elliptical top and bottom. The tank wall is made of aluminum and a multi-layered blanket of cryogenic insulation (MLI) has been attached on the top of the aluminum. The

Santosh K. Mukka; Muhammad M. Rahman

2004-01-01

320

Ice formation around a finned-tube heat exchanger for cold thermal energy storage  

Microsoft Academic Search

This paper addresses a numerical and experimental investigation of a cold thermal energy storage system involving phase-change process dominated by heat conduction. The problem involves a fluid flowing inside a horizontal finned tube surrounded by a phase-change material (PCM). The objective of this paper is to predict the temperature distribution, the phase front distribution along the tube and to analyze

N. Kayansayan; M. Ali Acar

2006-01-01

321

Heat-transfer considerations for large liquefied-natural-gas storage tanks  

Microsoft Academic Search

Natural gas is used worldwide as a practical energy source. In order to have a concentrated form of energy, natural gas is liquefied and stored under a pressure slightly above atmospheric and at a corresponding temperature just above its normal boiling point (112 K). This investigation presents a general steady-state study of the heat transfers into such a storage tank.

P. Jourda; S. D. Probert

1991-01-01

322

Review of mathematical modeling on latent heat thermal energy storage systems using phase-change material  

Microsoft Academic Search

Mathematical modeling of a latent heat thermal energy storage system (LHTES) was used for the optimum material selection and to assist in the optimal designing of the systems. In this paper, two types of models are mainly discussed, on the basis of first law and second law of thermodynamics. The important characteristics of different models and their assumptions used are

Prashant Verma; Varun; S. K. Singal

2008-01-01

323

A Study of the Storage and Ripening of Pears in Relation to Accumulated Heat Units.  

National Technical Information Service (NTIS)

Packham's Triumph and Beurre Bosc pears were stored for various times at various temperatures from -1.1 C to 5 C and then ripened at 20 C. The concept that the cool storage life of pears might be defined by a charateristic number of heat units (degree-day...

B. B. Beattie E. G. Hall G. G. Coote R. I. Baxter

1972-01-01

324

Evaluation and Assessment of Thermal-Energy Storage for Residential Heating.  

National Technical Information Service (NTIS)

In a field test in Maine and Vermont involving 75 households, 45 of which used off-peak electricity for heating, the overall technical performance and user acceptance of thermal-energy storage (TES) heaters were found to be satisfactory. Annual energy con...

H. Hersh G. Mirchandani R. Rowe

1982-01-01

325

Analysis of advanced thermal storage subsystems for solar heating and cooling. Final report, October 1, 1977September 30, 1978  

Microsoft Academic Search

Computer models for heating, cooling, and advanced thermal storage subsystems have been developed in TRNSYS-compatible form. Simplified models for solar collection and building loads have been written, together with routines that simulate a variety of space conditioning and advanced storage devices. Simulations using various storage concepts have been carried out for four major applications: (1) space and domestic hot water

P. O. D. Offenhartz; J. M. Marston; J. I. Watts

1979-01-01

326

Heat storage containers filled with the combination of a eutectic salt and a non-biodegradable filler material  

Microsoft Academic Search

A heat storage article adapted for prevention of stratification of heat storage materials, such as eutectic salts contained within the container element. The article is comprised of a heavy thermally conductive container with an internal cavity. The internal cavity of the container is substantially completely filled with a combination of a non-biodegradable filler material such as glass fiber insulation and

Schoenfelder

1980-01-01

327

A general model for analyzing the thermal characteristics of a class of latent heat thermal energy storage systems  

Microsoft Academic Search

The present study describes and classifies latent heat thermal energy storage (LHTES) systems according to their structural characteristics. A general model is developed for analyzing the thermal characteristics of the various typical LHTES systems to simulate thermal characteristics such as instantaneous heat transfer rate, instantaneous thermal storage capacity, etc. of the various typical LHTES systems. The model can calculate some

Kang Yanbing; Zhang Yinping; Jiang Yi; Zhu Yingxin

1999-01-01

328

Some aspects of two-phase flow, heat transfer and dynamic instabilities in medium and high pressure steam generators  

NASA Astrophysics Data System (ADS)

Experimental data for void fraction, incipient point of boiling, initial point of net vapor generation, bubble dynamics, dryout, two-phase flow pressure drop and density-wave oscillations were obtained in long, sodium heated steam generator tubes of different geometries for a wide range of operating conditions and at medium and high pressures. These data and data from literature taken in sodium and electrically heated steam generator tubes were correlated. Aspects of two-phase flow, heat transfer and density-wave oscillations in these steam generators disclosed include the distribution factor in small- and medium-size diameter steam generator tubes, the characteristic of the transitions at the incipient point of boiling and initial point of net vapor generation, bubble growth during subcooled nucleate flow boiling, the importance of the equivalent length for dryout in non-uniformly heated steam generator tubes and the mechanisms of density-wave oscillations in once-through steam generator tubes.

Unal, H. C.

1981-03-01

329

Seasonal-storage solar-energy heating system for the Charlestown, Boston Navy Yard National Historic Park. Phase II. Analysis with heat pump  

Microsoft Academic Search

This Phase II study provides further analysis for a seasonal-storage solar-heating system utilizing two existing underground, concrete tanks in the National Historic Park of the Charlestown Navy Yard in Boston. The initial Phase I study was reported in ANL-82-90. The new results focus on the effect of including a heat pump in the system to extend the useful heat-storage capacity

D. S. Breger; A. I. Michaels

1983-01-01

330

Hydromagnetic three-dimensional free convective heat transfer over a stretching surface embedded in a non-Darcian porous medium in the presence of heat generation or absorption  

NASA Astrophysics Data System (ADS)

A general analysis is developed to study fluid-flow and heat-transfer characteristics for steady, three-dimensional flow over a linearly stretching porous vertical surface embedded in a non-Darcian medium. A generalized flow model is used in the present study to include the effects of the macroscopic viscous term and the microscopic inertial force. The flow is subjected to a uniform transverse magnetic field normal to the plate. The effect of internal heat generation or absorption is also considered. The governing three-dimensional partial-differential equations for the present case are transformed into ordinary-differential equations using three-dimensional similarity variables. The resulting equations are solved numerically. Velocity distribution, temperature distribution, surface shear stresses, and wall-heat transfer rate are computed for various values of the Prandtl number, magnetic field parameter, inverse Darcy number, porous-medium inertia coefficient, heat generation/absorption coefficient, and mass-transfer coefficient.

Abo-Eldahab, E. M.; El Aziz, M. A.

2005-07-01

331

Thermal energy storage—A review of concepts and systems for heating and cooling applications in buildings: Part 1—Seasonal storage in the ground  

Microsoft Academic Search

The use of thermal energy storage (TES) in buildings in combination with space heating and\\/or space cooling has recently received much attention. A variety of TES techniques have developed over the past decades. TES systems can provide short-term storage for peak-load shaving as well as long-term (seasonal) storage for the introduction of natural and renewable energy sources. TES systems for

Georgi K. Pavlov; Bjarne W. Olesen

2012-01-01

332

Optimal coefficient of the share of cogeneration in the district heating system cooperating with thermal storage  

NASA Astrophysics Data System (ADS)

The paper presents the results of optimizing the coefficient of the share of cogeneration expressed by an empirical formula dedicated to designers, which will allow to determine the optimal value of the share of cogeneration in contemporary cogeneration systems with the thermal storages feeding the district heating systems. This formula bases on the algorithm of the choice of the optimal coefficient of the share of cogeneration in district heating systems with the thermal storage, taking into account additional benefits concerning the promotion of high-efficiency cogeneration and the decrease of the cost of CO2 emission thanks to cogeneration. The approach presented in this paper may be applicable both in combined heat and power (CHP) plants with back-pressure turbines and extraction-condensing turbines.

Zi?bik, Andrzej; G?adysz, Pawe?

2011-12-01

333

Thermal plumes and electric potentials generation in a porous medium locally heated from below  

NASA Astrophysics Data System (ADS)

The mechanism of convection and electric phenomena around an isolated heat source in a fluid saturated porous media is of interest in geothermal processes and volcanology. Laboratory and numerical experiments of transient convective flows and induced electric potentials in a porous layer with a local bottom heat source are reported. Laboratory characterization of fluid flow in porous media has a severe limitation by non-transparent nature of the media comparing to the case for a single fluid. In this study as for the temperature characterization, we utilized gridded thermocouples for multiple temperature measurement. As for the flow characterization, we set multiple electrodes to measure flow-induced potential. Axisymetric laminar plumes were experimentally generated by a small electric heater in a tank filled with water-saturated glass beads. We determined the spread of the plume with horizontally-gridded thermocouples, while vertical sets were used to characterize the time evolution of the plume ascent. Vertically-aligned electrodes along the central line exhibit large positive increase associated with plume ascent. The magnitude is consistent with the temperature increase and applied power. To understand the development of the plume, 2D-3D numerical simulations have been performed for the same situations of laboratory experiments. The flow pattern is investigated for Rayleigh numbers up to 8000. Plumes ascent in two different regimes. For Ra<1200, the velocity of the plume head slowly decreases during the ascension in the porous medium (consistent with Elder, 1967). For Ra>1200, the velocity increases owing to the development of the thermal boundary layer, remains nearly constant during the rise, before decreasing at the top of the tank. Finally, the electric potentials induced by the development of the plume are analyzed. It is shown that the signal initially decreases when the plume is detaching itself from the bottom, but largely increases during the ascension of the water, which is systematically observed in experimental results. We consider flow-induced potential as a good experimental probe for fluid flow characterization in porous media. This study is the first step to further experimental and numerical works on convective cells generation and induced electric potentials in a stratified porous medium.

Antoine, R.; Kurita, K.

2010-12-01

334

Analytical and experimental investigations of sodium heat pipes and thermal energy storage systems  

NASA Astrophysics Data System (ADS)

Eight work elements for FY 1981 are reported on. A brief evaluation of the limits of arterial heat pipes is presented followed by the post life examination of two Inconel 600, sodium heat pipes which failed by pin hole corrosion through the evaporator. Nearly 12,000 hours of operation was sustained by one of the heat pipes prior to failure. A parametric test station for a thermal train including a 15-foot Inconel 617-sodium heat. A secondary sodium heat pipe with integral LiF thermal energy storage capsules and a sodium thermal transfer joint is discussed. A series of fifteen 18-in. long by 0.5 in. diameter Inconel 617, sodium heat pipes are being prepared for parametric and life tests. A 12-in. long, 1-in. diameter Inconel 617 container filled with the thermal energy storage salt 64LiF-30 MgF2-6KF was tested to determine latent heat of fusion (782 J/gm), melting point (710 C), freezing point (671 C) and diffusivity (0.00799 sq cm/sec) of the salt. The post life test results of a series of nine salt-Inconel 600 capsules, including LiF-MgF2, LiF-MgF2 -KF, and LiF-MgF2 NaF are presented. A 321 stainless steel, sodium heat pipe containing three LiF thermal energy storage units has a total of over 10,700 hours of operation and 3426 cycles of life testing.

Jacobson, D.

1982-01-01

335

Experimental study on latent heat storage characteristics of W/O emulsion -Supercooling rate of dispersed water drops by direct contact heat exchange-  

NASA Astrophysics Data System (ADS)

Recently, much attention has been paid to investigate the latent heat storage system. Using of ice heat storage system brings an equalization of electric power demand, because it will solved the electric -power-demand-concentration on day-time of summer by the air conditioning. The flowable latent heat storage material, Oil/Water type emulsion, microencapsulated latent heat material-water mixture or ice slurry, etc., is enable to transport the latent heat in a pipe. The flowable latent heat storage material can realize the pipe size reduction and system efficiency improvement. Supercooling phenomenon of the dispersed latent heat storage material in continuous phase brings the obstruction of latent heat storage. The latent heat storage rates of dispersed water drops in W/O (Water/Oil) emulsion are investigated experimentally in this study. The water drops in emulsion has the diameter within 3 ˜ 25?m, the averaged water drop diameter is 7.3?m and the standard deviation is 2.9?m. The direct contact heat exchange method is chosen as the phase change rate evaluation of water drops in W/O emulsion. The supercooled temperature and the cooling rate are set as parameters of this study. The evaluation is performed by comparison between the results of this study and the past research. The obtained experimental result is shown that the 35K or more degree from melting point brings 100% latent heat storage rate of W/O emulsion. It was clarified that the supercooling rate of dispersed water particles in emulsion shows the larger value than that of the bulk water.

Morita, Shin-ichi; Hayamizu, Yasutaka; Horibe, Akihiko; Haruki, Naoto; Inaba, Hideo

2013-04-01

336

Thermal performance of a heat storage module using PCM's with different melting temperature; Experimental  

SciTech Connect

A latent heat storage module was constructed, consisting of 45 cylindrical capsules fixed vertically in 15 rows. The capsules, made of 0.335-m long copper tubes having external diameters of 31.8 mm, were fixed in an insulated rectangular duct. Three commercial waxes having melting temperatures of 44{degrees}C, 53{degrees}C, and 64{degrees}C were selected. Each of the three sets of 15 tubes was filled with different wax. For comparison purposes, experiments were also done with a single commercial wax, having a melting temperature of 53{degrees}C, in all the tubes. During heat charge, hot air flowed across the capsules such that the melting temperature of the waxes decreased in the flow direction. Air flow direction was reversed during heat discharge. This paper reports that experimental measurements showed some improvement in the heat transfer rates during both heat charge and discharge when three types of PCM's were used.

Farid, M.M. (Chemical Engineering Dept., College of Engineering, Univ. of Basrah (IQ)); Kim, Y.; Kansawa, A. (Chemical Engineering Dept., Tokyo Inst. of Technology, O-Okayama, Meguro-Ku, Tokyo 152 (JP))

1990-05-01

337

Research on solar energy storage subsystems utilizing the latent heat of phase change of paraffin hydrocarbons for the heating and cooling of buildings  

Microsoft Academic Search

An analytical and experimental research program designed to assess the potential of a solar energy storage subsystem (thermal capacitor) using the latent heat of fusion of paraffin hydrocarbons for the heating and cooling of buildings, is described. An idealized model of a flat plate thermal capacitor based on uniaxial heat conduction with a change of phase and an absence of

J. A. Bailey; J. C. Mulligan; C. K. Liao; S. I. Guceri

1975-01-01

338

Two-tank molten salt storage for parabolic trough solar power plants  

Microsoft Academic Search

The most advanced thermal energy storage for solar thermal power plants is a two-tank storage system where the heat transfer fluid (HTF) also serves as storage medium. This concept was successfully demonstrated in a commercial trough plant (13.8 MWe SEGS I plant; 120 MWht storage capacity) and a demonstration tower plant (10 MWe Solar Two; 105 MWht storage capacity). However,

Ulf Herrmann; Bruce Kelly; Henry Price

2004-01-01

339

Integrated hydrological modelling of small- and medium-sized water storages with application to the upper Fengman Reservoir Basin of China  

NASA Astrophysics Data System (ADS)

Hydrological simulation in regions with a large number of water storages is difficult due to inaccurate water storage data. To address this issue, this paper presents an improved version of SWAT2005 (Soil and Water Assessment Tool, version 2005) using Landsat, a satellite-based dataset, an empirical storage classification method and some empirical relationships to estimate water storage and release from the various sizes of flow detention and regulation facilities. The SWAT2005 is enhanced by three features: (1) a realistic representation of the relationships between the surface area and volume of each type of water storages, ranging from small-sized flow detention ponds to medium- and large-sized reservoirs with the various flow regulation functions; (2) water balance and transport through a network combining both sequential and parallel streams and storage links; and (3) calibrations for both physical and human interference parameters. Through a real-world watershed case study, it is found that the improved SWAT2005 more accurately models small- and medium-sized storages than the original model in reproducing streamflows in the watershed. The improved SWAT2005 can be an effective tool to assess the impact of water storage on hydrologic processes, which has not been well addressed in the current modelling exercises.

Zhang, C.; Peng, Y.; Chu, J.; Shoemaker, C. A.; Zhang, A.

2012-11-01

340

Proceedings of the Workshop on Solar Energy Storage Subsystems for the Heating and Cooling of Buildings, Held at Charlottesville, Virginia on April 16-18, 1975.  

National Technical Information Service (NTIS)

The current status of the thermal energy storage field, particularly as it relates to energy storage subsystems in buildings is reviewed. Topics ranged from the sensible heat storage in water to latent heat storage in chemical bonds; from use of hot water...

L. U. Lilleleht J. T. Beard F. A. Iachetta

1975-01-01

341

Maintenance and storage of fuel oil for residential heating systems: A guide for residential heating system maintenance personnel  

SciTech Connect

The quality of No. 2 fuel affects the performance of the heating system and is an important parameter in the proper and efficient operation of an oil-burning system. The physical and chemical characteristics of the fuel can affect the flow, atomization and combustion processes, all of which help to define and limit the overall performance of the heating system. The use of chemical additives by fuel oil marketershas become more common as a method of improving the quality of the fuel, especially for handling and storage. Numerous types of additives are available, but reliable information on their effectiveness and proper use is limited. This makes selecting an additive difficult in many situations. Common types of problems that contribute to poor fuel quality and how they affect residential heating equipment are identified inof this booklet. It covers the key items that are needed in an effective fuel quality monitoring program, such as what to look for when evaluating the quality of fuel as it is received from a supplier, or how to assess fuel problems associated with poor storage conditions. References to standard procedures and brief descriptions of the procedures also are given. Approaches for correcting a fuel-related problem, including the potential uses of chemical additives are discussed. Different types of additives are described to help users understand the functions and limitations of chemical treatment. Tips on how to select andeffectively use additives also are included. Finally, the importance of preventative maintenance in any fuel monitoring program is emphasized.

Litzke, Wai-Lin

1992-12-01

342

Heating and cooling of a hospital using solar energy coupled with seasonal thermal energy storage in an aquifer  

Microsoft Academic Search

A system is being designed, using solar energy in combination with Aquifer Thermal Energy Storage (ATES), that will conserve a major part of the oil and electricity used for heating or cooling the Cukurova University, Balcali Hospital in Adana, Turkey. The general objective of the system is to provide heating and cooling to the hospital by storing solar heat underground

H. O Paksoy; O Andersson; S Abaci; H Evliya; B Turgut

2000-01-01

343

Numerical simulation of heat and mass transfer in metal hydride hydrogen storage tanks for fuel cell vehicles  

Microsoft Academic Search

This paper presents a two-dimensional mathematical model to optimized heat and mass transfer in metal hydride storage tanks (hereinafter MHSTs) for fuel cell vehicles, equipped with finned spiral tube heat exchangers. This model which considers complex heat and mass transfer was numerically solved and validated by comparison with experimental data and a good agreement is obtained.A study of the effect

S. Mellouli; F. Askri; H. Dhaou; A. Jemni; S. Ben Nasrallah

2010-01-01

344

Method of forming a solar collector or hot water storage tank and solar water heating apparatus using same  

Microsoft Academic Search

The present invention relates to a method of forming a solar collector, or absorber, panels or a heat storage tank, suitable for heating water using solar energy. It also relates to articles of manufacture so formed and to solar water heating apparatus using said articles. Three methods of forming the panel or tank from two sheets of uncured elastic material,

H. M. Anderson; M. E. Negley

1984-01-01

345

Lauric and palmitic acids eutectic mixture as latent heat storage material for low temperature heating applications  

Microsoft Academic Search

Palmitic acid (PA, 59.8°C) and lauric acid (LA, 42.6°C) are phase change materials (PCM) having quite high melting temperatures which can limit their use in low temperature solar applications such as solar space heating and greenhouse heating. However, their melting temperatures can be tailored to appropriate value by preparing a eutectic mixture of the lauric and the palmitic acids. In

Kadir Tunçbilek; Ahmet Sari; Sefa Tarhan; Gazanfer Ergüne?; Kamil Kaygusuz

2005-01-01

346

Improvement of the performance of solar energy or waste heat utilization systems by using phase-change slurry as an enhanced heat-transfer storage fluid  

Microsoft Academic Search

This paper is concerned with the benefits of using phase-change slurries as enhanced heat-transfer\\/storage working fluids in solar energy and waste heat utilization systems. Literature is cited to show that a slurry containing a phase-change material as the dispersed phase promises to have much higher heat-transfer coefficients than conventional single-phase working fluids. Because of the latent heat, the phasechange slurry

K. E. Kasza; M. M. Chen

1985-01-01

347

Effects of heat processing and storage on flavanols and sensory qualities of green tea beverage.  

PubMed

This research was conducted to understand the effects of heat processing and storage on flavanols and sensory qualities of green tea extract. Fresh tea leaves were processed into steamed and roasted green teas by commercial methods and then extracted with hot water (80 degrees C) at 1:160 ratio (tea leaves/water by weight). Green tea extracts were heat processed at 121 degrees C for 1 min and then stored at 50 degrees C to accelerate chemical reactions. Changes in flavanol composition and sensory qualities of green tea extracts during processing and storage were measured. Eight major flavanols (catechin, epicatechin, gallocatechin, epigallocatechin, epicatechin gallate, catechin gallate, epigallocatechin gallate, and gallocatechin gallate) were identified in the processed tea extract. Among them, epigallocatechin gallate and epigallocatechin appeared to play the key role in the changes of sensory qualities of processed green tea beverage. The steamed tea leaves produced a more desirable quality of processed green tea beverage than the roasted ones. PMID:10995342

Wang, L F; Kim, D M; Lee, C Y

2000-09-01

348

Salt-hydrate thermal-energy-storage system for space heating and air conditioning  

NASA Astrophysics Data System (ADS)

Latent heat storage equipment using three different salts was developed. The salts are: sodium sulfate pentahydrate which melts at 460 C, magnesium chloride hexahydrate which melts at 1150 C, and a eutectic combination of seven different materials which melts at 70 C. Stirring pumps, tanks, and tubing materials, and field filling of the salts into their tanks are developed. good performance for the tank/heat exchangers with all three salts is reported. Both the 1150 C and 460 C salts are almost equivalent in volume storage to water/ice. The 79.0 C salt, however, begins at about 56% of the BTU's per cubic foot of water/ice and declines due to separation to 40% after repeated cycling.

MacCracken, C. D.; Armstrong, J. M.; MacCracken, M. M.; Silvetti, B. M.

1980-07-01

349

Experimental analysis of regularly structured composite latent heat storages for temporary cooling of electronic components  

NASA Astrophysics Data System (ADS)

This study presents the experimental investigation of regularly structured Composite Latent Heat Storages. Solid-liquid Phase Change Materials have a low thermal conductivity, resulting in high temperature differences. This drawback is compensated by the combination with specially designed frame-structures made of aluminum to enhance the transport of thermal energy. A prototype is investigated experimentally on a test rig, where the heat load and temperatures are measured while the phase change process is observed optically, and compared to a solid block Phase Change Material.

Lohse, Ekkehard; Schmitz, Gerhard

2013-11-01

350

Integrated hydrological modelling of small- and medium-sized water storages with application to the upper Fengman Reservoir Basin of China  

NASA Astrophysics Data System (ADS)

Hydrological simulation in regions with a large number of water storages is difficult due to the inaccurate water storage data, including both topologic parameters and operational rules. To address this issue, this paper presents an improved version of SWAT2005 (Soil and Water Assessment Tool, version 2005) using the satellite-based dataset Landsat, an empirical storage classification method, and some empirical relationships to estimate water storage and release from the various levels of flow regulation facilities. The improved SWAT2005 is characterised by three features: (1) a realistic representation of the relationships between the water surface area and volume of each type of water storage, ranging from small-sized ponds for water flow regulation to large-sized and medium-sized reservoirs for water supply and hydropower generation; (2) water balance and transport through a network combining both sequential and parallel streams and storage links; and (3) calibrations for the physical parameters and the human interference parameters. Both the original and improved SWAT2005 are applied to the upper Fengman Reservoir Basin, and the results of these applications are compared. The improved SWAT2005 accurately models small- and medium-sized storages, indicating a significantly improved performance from that of the original model in reproducing streamflows.

Zhang, C.; Peng, Y.; Chu, J.; Shoemaker, C. A.

2012-03-01

351

Efficacy of tertiary butylhydroquinone on the storage and heat stability of liquid canola shortening  

Microsoft Academic Search

The sensory (odor and flavor) and physicochemical characteristics of tertiary butylhydroquinone (TBHQ) treated and butylated\\u000a hydroxyanisole\\/toluene (BHA\\/BHT) treated liquid canola shortenings, subjected to accelerated storage (Schaal oven test at\\u000a 65C) and deep fat heating (at 185C), were determined. Data for the Schaal oven test indicate that TBHQ was effective in\\u000a retarding oxidative rancidity in liquid canola shortenings. However, addition of

Z. J. Hawrysh; P. J. Shand; C. Lin; B. Tokarska; R. T. Hardin

1990-01-01

352

Capric Acid and Myristic Acid for Latent Heat Thermal Energy Storage  

Microsoft Academic Search

The present study was focused on three aims: (1) preparation of the phase-change gypsum wallboard as novel phase-change wallboard incorporated with the eutectic mixture of capric acid (CA) and myristic acid (MA) for latent heat thermal energy storage (LHTES); (2) determination of thermal properties and thermal reliability of prepared phase-change wallboard using differential scanning calorimetry (DSC) technique; and (3) estimation

A. Sari; A. Karaipekli; K. Kaygusuz

2008-01-01

353

Use of segmented sensible heat thermal storage devices for near isothermal operation  

SciTech Connect

A study has been performed to assess the capability of sensible heat thermal storage devices (TSDs) for cryogenic applications requiring close temperature control. The advantages obtained by segmentation have been quantified for TSDs used for fluid thermal tempering for periodic flow devices. Such devices offer an attractive alternative to TSDs employing phase change materials (PCMs). Finally, the use of segmented TSDs is applied to a Periodic 10 K Sorption Cryocooler. {copyright} {ital 1996 American Institute of Physics.}

Barr, K.P. [AlliedSignal, Aerospace Equipment Systems, 2525 W. 190th St., M/S TOR-36-1-93140, Torrance, California 90504-6099 (United States)

1996-03-01

354

Active heat exchange system development for latent heat thermal energy storage  

NASA Astrophysics Data System (ADS)

Alternative mechanizations of active heat exchange concepts were analyzed for use with heat of fusion Phase Change Materials (PCM's) in the temperature range of 250 C to 350 C for solar and conventional power plant applications. Over 24 heat exchange concepts were reviewed, and eight were selected for detailed assessment. Two candidates were chosen for small-scale experimentation: a coated tube and shell that exchanger, and a direct contact reflux boiler. A dilute eutectic mixture of sodium nitrate and sodium hydroxide was selected as the PCM from over fifty inorganic salt mixtures investigated. Preliminary experiments with various tube coatings indicated that a nickel or chrome plating of Teflon or Ryton coating had promise of being successful. An electroless nickel plating was selected for further testing. A series of tests with nickel-plated heat transfer tubes showed that the solidifying sodium nitrate adhered to the tubes and the experiment failed to meet the required discharge heat transfer rate of 10 kW(t). Testing of the reflux boiler is under way.

Lefrois, R. T.

1980-03-01

355

System for thermal energy storage, space heating and cooling and power conversion  

DOEpatents

An integrated system for storing thermal energy, for space heating and cong and for power conversion is described which utilizes the reversible thermal decomposition characteristics of two hydrides having different decomposition pressures at the same temperature for energy storage and space conditioning and the expansion of high-pressure hydrogen for power conversion. The system consists of a plurality of reaction vessels, at least one containing each of the different hydrides, three loops of circulating heat transfer fluid which can be selectively coupled to the vessels for supplying the heat of decomposition from any appropriate source of thermal energy from the outside ambient environment or from the spaces to be cooled and for removing the heat of reaction to the outside ambient environment or to the spaces to be heated, and a hydrogen loop for directing the flow of hydrogen gas between the vessels. When used for power conversion, at least two vessels contain the same hydride and the hydrogen loop contains an expansion engine. The system is particularly suitable for the utilization of thermal energy supplied by solar collectors and concentrators, but may be used with any source of heat, including a source of low-grade heat.

Gruen, Dieter M. (Downers Grove, IL); Fields, Paul R. (Chicago, IL)

1981-04-21

356

Simultaneous estimation of strength and position of a heat source in a participating medium using DE algorithm  

NASA Astrophysics Data System (ADS)

An inverse heat transfer problem is discussed to estimate simultaneously the unknown position and timewise varying strength of a heat source by utilizing differential evolution approach. A two dimensional enclosure with isothermal and black boundaries containing non-scattering, absorbing and emitting gray medium is considered. Both radiation and conduction heat transfer are included. No prior information is used for the functional form of timewise varying strength of heat source. The finite volume method is used to solve the radiative transfer equation and the energy equation. In this work, instead of measured data, some temperature data required in the solution of the inverse problem are taken from the solution of the direct problem. The effect of measurement errors on the accuracy of estimation is examined by introducing errors in the temperature data of the direct problem. The prediction of source strength and its position by the differential evolution (DE) algorithm is found to be quite reasonable.

Parwani, Ajit K.; Talukdar, Prabal; Subbarao, P. M. V.

2013-09-01

357

Solar passive ceiling system. Final report. [Passive solar heating system with venetian blind reflectors and latent heat storage in ceiling  

SciTech Connect

The construction of a 1200 square foot building, with full basement, built to be used as a branch library in a rural area is described. The primary heating source is a passive solar system consisting of a south facing window system. The system consists of: a set of windows located in the south facing wall only, composed of double glazed units; a set of reflectors mounted in each window which reflects sunlight up to the ceiling (the reflectors are similar to venetian blinds); a storage area in the ceiling which absorbs the heat from the reflected sunlight and stores it in foil salt pouches laid in the ceiling; and an automated curtain which automatically covers and uncovers the south facing window system. The system is totally passive and uses no blowers, pumps or other active types of heat distribution equipment. The building contains a basement which is normally not heated, and the north facing wall is bermed four feet high around the north side.

Schneider, A.R.

1980-01-01

358

Gas hydrate cool storage system  

DOEpatents

The invention presented relates to the development of a process utilizing a gas hydrate as a cool storage medium for alleviating electric load demands during peak usage periods. Several objectives of the invention are mentioned concerning the formation of the gas hydrate as storage material in a thermal energy storage system within a heat pump cycle system. The gas hydrate was formed using a refrigerant in water and an example with R-12 refrigerant is included. (BCS)

Ternes, M.P.; Kedl, R.J.

1984-09-12

359

Production of Excess Heat Power on the basis of Low Energy Nuclear Reactions (LERN) in the Solid Medium  

Microsoft Academic Search

The experimental data of investigation into low energy nuclear reactions (LERN) in condensed media are presented. The nuclear reactions products were researched in the solid cathode medium of a glow discharge. Hypothetically the nuclear reactions were initiated when bombarding the cathode surface by plasma ions with the energy of 1.0-2.0 keV. The results on recording excess heat power under the

Karabut

2004-01-01

360

Non-Darcy Fully Developed Mixed Convection in a Porous Medium Channel with Heat Generation\\/absorption and Hydromagnetic Effects  

Microsoft Academic Search

Volume-averaged equations are developed governing steady, laminar, fully developed, hydromagnetic mixed convection non-Darcian flow of an electrically conducting and heat-generating \\/ absorbing fluid in a channel embedded in a uniform porous medium. Proper dimensionless parameters are employed for various thermal boundary conditions on the left and right walk of the channel prescribed as isothermal-isothermal, isothermal-iso-flux, and isoflux-isothermal. Analytical expressions for

Ali J. Chamkha

1997-01-01

361

Computational modeling of biomagnetic micropolar blood flow and heat transfer in a two-dimensional non-Darcian porous medium  

Microsoft Academic Search

We study theoretically and computationally the incompressible, non-conducting, micropolar, biomagnetic (blood) flow and heat\\u000a transfer through a two-dimensional square porous medium in an (x,y) coordinate system, bound by impermeable walls. The magnetic field acting on the fluid is generated by an electrical current\\u000a flowing normal to the x–y plane, at a distance l beneath the base side of the square.

O. Anwar Bég; R. Bhargava; S. Rawat; Kalim Halim; H. S. Takhar

2008-01-01

362

Rapid Induction Heat Treatment of Articles from Plain and Low-Alloy Low-Carbon and Medium-Carbon Steels  

Microsoft Academic Search

A new method of rapid induction heat treatment (RIHT) of articles and semiproducts from plain and low-alloy low-carbon and medium-carbon steels is described. The method ensures a high ductility at a strength at least no lower than the initial one and a high strength at a ductility higher than the initial one. Examples of pipes from steels 15G2 and 20

N. V. Zimin; O. S. Martynov

2005-01-01

363

Storage tank heat losses through thermosiphoning in two SFBP (the Solar in Federal Buildings Program) solar systems  

SciTech Connect

Comprehensive monitoring and performance analyses of Solar in Federal Buildings Program (SFBP) quality sites indicated that storage tank heat losses were significantly higher than design estimates. In some cases, measured losses were as much as 10 times the calculated losses. One potentially significant source of heat loss in solar systems is thermosiphoning. A series of tests was conducted at two SFBP quality solar systems to investigate the existence and magnitude of thermosiphon losses from storage subsystems.

Francetic, J.S.; Robinson, K.S.

1987-07-01

364

Heat storage containers filled with the combination of a eutectic salt and a non-biodegradable filler material  

SciTech Connect

A heat storage article adapted for prevention of stratification of heat storage materials, such as eutectic salts contained within the container element. The article is comprised of a heavy thermally conductive container with an internal cavity. The internal cavity of the container is substantially completely filled with a combination of a non-biodegradable filler material such as glass fiber insulation and a eutectic salt.

Schoenfelder, J.L.

1980-09-23

365

Thermal performance evaluation of a latent heat storage unit for late evening cooking in a solar cooker having three reflectors  

Microsoft Academic Search

In this paper, a phase change material (PCM) storage unit for a solar cooker was designed and developed to store energy during sunshine hours. The stored energy was utilised to cook food in the late evening. Commercial grade acetanilide (melting point 118.9 °C, latent heat of fusion 222 kJ\\/kg) was used as a latent heat storage material. Evening cooking experiments

D Buddhi; S. D Sharma; Atul Sharma

2003-01-01

366

Solar assisted absorption or motor driven heat pump with earth seasonal storage. Part 2: Tables and figures  

Microsoft Academic Search

A plant composed of an energy roof, a seasonal earth storage and an absorption heat pump has been tested. The purpose was to study the behavior of the various components and their interaction. The surveys went on during two years. The following operations are considered: the charging of the earth storage by the energy roof and the working of an

R. M. Lazzarin

1986-01-01

367

Heat Storage in a Groundwater Reservoir Through Induced Infiltration of Surface Water. A Case Study in Hoegsby.  

National Technical Information Service (NTIS)

The objective of this project has been to investigate the feasibility of utilising the Hoegsby ridge and the Emaa river to produce a heat storage system in a groundwater reservoir. The principle involves storage during the summer of warm surface water in ...

P. Olsson

1987-01-01

368

Thermal energy storage Stirling engine power plants 1: Calculated heat transfer and pressure drop across ground power unit heater assemblies  

Microsoft Academic Search

A power plant basically consisting of a thermal energy storage tank, an existing ground power unit-size Stirling engine and a gas circulating system for transporting energy from the thermal energy storage tank to the engine is considered. The external heat transfer to the engine heater and attendant circulating gas pumping losses are analytically studied. Results show that the pumping losses

J. C. Steiner

1978-01-01

369

Heat transfer in a high-temperature packed bed thermal energy storage system -- Roles of radiation and intraparticle conduction  

Microsoft Academic Search

A model is developed and experimentally verified to study the heat transfer in a high-temperature packed bed thermal energy storage system utilizing zirconium oxide pellets. The packed bed receives flue gas at elevated temperatures varying with time during the storage process and utilizes air for the recovery process. Both convection and radiation are included in the model of the total

A. A. Jalalzadeh-Azar; W. G. Steele; G. A. Adebiyi

1996-01-01

370

Heat transfer and parametric studies of an encapsulated phase change material based cool thermal energy storage system  

Microsoft Academic Search

This work investigates the transient behaviour of a phase change material based cool thermal energy storage (CTES) system comprised of a cylindrical storage tank filled with encapsulated phase change materials (PCMs) in spherical container integrated with an ethylene glycol chiller plant. A simulation program was developed to evaluate the temperature histories of the heat transfer fluid (HTF) and the phase

371

Design, development and performance evaluation of a latent heat storage unit for evening cooking in a solar cooker  

Microsoft Academic Search

In this paper, a PCM storage unit for a solar cooker was designed and developed to store solar energy during sunshine hours. The stored energy was utilised to cook food in the evening. Commercial grade acetamide was used as a latent heat storage material. Cooking experiments were conducted with different loads and loading times during the summer and winter seasons.

S. D Sharma; D Buddhi; R. L Sawhney; Atul Sharma

2000-01-01

372

The use of ground heat storages and evacuated tube solar collectors for meeting the annual heating demand of family-sized houses  

Microsoft Academic Search

The use of storages for sensible heat is limited because parts of the input thermal energy end up as unavoidable heat losses. In order to minimize this loss, it is necessary to keep the surface area to volume ratio (S\\/V) as low as possible. This occurs when the volume of a body with a certain shape increases. In addition to

J. A. Kroll; F. Ziegler

2011-01-01

373

Heat storage in Asian elephants during submaximal exercise: behavioral regulation of thermoregulatory constraints on activity in endothermic gigantotherms.  

PubMed

Gigantic size presents both opportunities and challenges in thermoregulation. Allometric scaling relationships suggest that gigantic animals have difficulty dissipating metabolic heat. Large body size permits the maintenance of fairly constant core body temperatures in ectothermic animals by means of gigantothermy. Conversely, gigantothermy combined with endothermic metabolic rate and activity likely results in heat production rates that exceed heat loss rates. In tropical environments, it has been suggested that a substantial rate of heat storage might result in a potentially lethal rise in core body temperature in both elephants and endothermic dinosaurs. However, the behavioral choice of nocturnal activity might reduce heat storage. We sought to test the hypothesis that there is a functionally significant relationship between heat storage and locomotion in Asian elephants (Elephas maximus), and model the thermoregulatory constraints on activity in elephants and a similarly sized migratory dinosaur, Edmontosaurus. Pre- and post-exercise (N=37 trials) measurements of core body temperature and skin temperature, using thermography were made in two adult female Asian elephants at the Audubon Zoo in New Orleans, LA, USA. Over ambient air temperatures ranging from 8 to 34.5°C, when elephants exercised in full sun, ~56 to 100% of active metabolic heat production was stored in core body tissues. We estimate that during nocturnal activity, in the absence of solar radiation, between 5 and 64% of metabolic heat production would be stored in core tissues. Potentially lethal rates of heat storage in active elephants and Edmontosaurus could be behaviorally regulated by nocturnal activity. PMID:23785105

Rowe, M F; Bakken, G S; Ratliff, J J; Langman, V A

2013-05-15

374

A mathematical model for two-phase water, air, and heat flow around a linear heat source emplaced in a permeable medium  

SciTech Connect

A semianalytical solution for transient two-phase water, air, and heat flow in a uniform porous medium surrounding a constant-strength linear heat source has been developed, using a similarity variable {eta}=r/{radical}t (r is radial distance, t is time). Although the similarity transformation requires a simplified radial geometry, all the physical mechanisms involved in two-phase fluid and heat flow may be taken into account in a rigorous way. The solution includes nonlinear thermophysical fluid and material properties, such as relative permeability and capillary pressure variations with saturation, and density and viscosity variations with temperature and pressure. The resulting governing equations form a set of coupled nonlinear ODEs, necessitating numerical integration. The solution has been applied to a partially saturated porous medium initially at a temperature well below the saturation temperature, which is the setting for the potential nuclear waste repository site at Yucca Mountain, Nevada. The resulting heat and fluid flows provide a stringent test of many of the capabilities of numerical simulation models, making the similarity solution a useful tool for model verification. Comparisons to date have shown excellent agreement between the TOUGH2 simulator and the similarity solution for a variety of conditions. 13 refs., 6 figs., 1 tab.

Doughty, C.; Pruess, K.

1991-03-01

375

Analysis of solar-powered absorption cycle heat pumps with internal/external energy storages  

NASA Astrophysics Data System (ADS)

System diagrams and performance equations are presented for solar-powered water-lithium bromide absorption cycle heat pump systems utilizing two different modes of energy storage. In the ETS system the collector is coupled to the absorption cycle generator through a thermal energy storage external to the other elements of the system. In the ILES system the collector is coupled directly to the absorption cycle generator with latent energy storage internal to the cycle itself. Discrete-time computer models of the systems are constructed to enable operational and parameter studies to be carried out. Generalized weather functions are used to represent insolation and building load demands to the systems. Operating strategies to minimize auxiliary energy requirements and to maximize the utilization of solar energy are described for each system. Parameter studies were carried out in terms of system cost and solar energy supply fraction versus storage size and insolation to load ratio (collector area). Comparisons between the ETS and ILES systems show that the greater capital cost of the ILES system is offset by higher solar energy utilization.

Harris, A. W.; Shen, C. N.

376

Effects of heat exchanger tube geometries on nucleate pool boiling heat transfer in a scaled in-containment refueling water storage tank  

Microsoft Academic Search

To determine the combined effects of the heat exchanger tube geometries of advanced light water reactors (ALWRs) passive residual heat removal system (PRHRS) on the nucleate pool boiling heat transfer in a scaled in-containment refueling water storage tank (IRWST), a total of 1,966 data (1,076 with horizontal tubes and 890 with vertical tubes) for q? versus ?T has been obtained

Moon-Hyun Chun; Myeong-Gie Kang

1996-01-01

377

A simulation study on solar energy seasonal storage by phase change material  

Microsoft Academic Search

Solar heating systems with seasonal energy storage have attracted an increasing attention over the past decades. The availability of solar energy is intermittent, thus heat storage is an indispensable element in a solar energy based building thermal system. However, studies of such systems using a phase change material (PCM) as seasonal storage medium have not been found in the previous

Qi Qi; Yiqiang Jiang; Shiming Deng

2008-01-01

378

High-temperature integrated thermal-energy-storage system for solar-thermal applications  

Microsoft Academic Search

An analysis is presented of a novel, very high temperature solar thermal energy storage system which uses molten slag as the storage medium. Slat bead aggregate is melted in a solar central receiver and stored in liquid form at 16500K in an insulated refractory storage vessel. Sensible heat is extracted from the molten slag in a direct-contact droplet heat exchanger,

A. P. Bruckner; A. Hertzberg

1982-01-01

379

Thermal analysis of heat storage canisters for a solar dynamic, space power system  

SciTech Connect

A thermal analysis was performed of a thermal energy storage canister of a type suggested for use in a solar receiver for an orbiting Brayton cycle power system. Energy storage for the eclipse portion of the cycle is provided by the latent heat of a eutectic mixture of LiF and CaF/sub 2/ contained in the canister. The chief motivation for the study is the prediction of vapor void effects on temperature profiles and the identification of possible differences between ground test data and projected behavior in microgravity. The first phase of this study is based on a two-dimensional, cylindrical coordinates model using an interim procedure for describing void behavior in 1/minus/g and microgravity. The thermal anaylsis includes the effects of solidification front behavior, conduction in liquid/solid salt and canister materials, void growth and shrinkage, radiant heat transfer across the void, and convection in the melt due to Marangoni-induced flow and, in 1/minus/g, flow due to density gradients. A number of significant differences between 1/minus/g and 0/minus/g behavior were found. These resulted from differences in void location relative to the maximum heat flux and a significantly smaller effective conductance in 0/minus/g due to the absence of gravity-induced convection.

Wichner, R.P.; Solomon, A.D.; Drake, J.B.; Williams, P.T.

1988-04-01

380

Automatic control of electric thermal storage (heat) under real-time pricing. Final report  

SciTech Connect

Real-time pricing (RTP) can be used by electric utilities as a control signal for responsive demand-side management (DSM) programs. Electric thermal storage (ETS) systems in buildings provide the inherent flexibility needed to take advantage of variations in prices. Under RTP, optimal performance for ETS operations is achieved under market conditions where reductions in customers` costs coincide with the lowering of the cost of service for electric utilities. The RTP signal conveys the time-varying actual marginal cost of the electric service to customers. The RTP rate is a combination of various cost components, including marginal generation fuel and maintenance costs, marginal costs of transmission and distribution losses, and marginal quality of supply and transmission costs. This report describes the results of an experiment in automatic control of heat storage systems under RTP during the winter seasons of 1989--90 and 1990--91.

Daryanian, B.; Tabors, R.D.; Bohn, R.E. [Tabors Caramanis and Associates, Inc. (United States)

1995-01-01

381

Effect of Heating Treatments, Processing Methods and Refrigerated Storage of Milk and Some Dairy Products on Lipids Oxidation  

Microsoft Academic Search

The effect of heating treatments (pasteurization and boiling), micro waving, processing steps and storage of milk and some locally produced dairy products (Brined white cheese (Nabulsi), Yogurt and Labaneh on chemical changes of milk lipids were evaluated. The Peroxide value (POV) p-anisidine value (p-AV), thiobarbituric acid (TBA), free fatty acid and totox were determined. The heating treatments of milk do

2008-01-01

382

Experimental analysis and numerical modelling of inward solidification on a finned vertical tube for a latent heat storage unit  

Microsoft Academic Search

The enhancement of heat transfer in a thermal storage system consisting of a cylindrical vertical tube with internal longitudinal fin arrangement is discussed in this paper. This configuration that forms a V-shaped enclosure for the phase change material (PCM) gives maximum benefit to the fin arrangement. A theoretical model that also accounts for the circumferential heat flow through the tube

R. Velraj; R. V. Seeniraj; B. Hafner; C. Faber; K. Schwarzer

1997-01-01

383

Research on Charge and Discharge Characteristic of Heat Storage Tank Filled with Form-Stable Phase Change Material  

Microsoft Academic Search

This paper describes the comparative study of experimental and numerical results on charge and discharge characteristic of heat storage tank filled with form-stable PCM (FS-PCM) and water used as heat transfer fluid (HTF). During the different experimental conditions, the effect of verifying the velocity of HTF, and flow direction of HTF and inlet temperature of HTF on charge and discharge

Li Xiangling; Chen Chao; Ouyang Jun

384

Effect of Heat and Electricity Storage and Reliability on Microgrid Viability:A Study of Commercial Buildings in California and New York States  

SciTech Connect

In past work, Berkeley Lab has developed the Distributed Energy Resources Customer Adoption Model (DER-CAM). Given end-use energy details for a facility, a description of its economic environment and a menu of available equipment, DER-CAM finds the optimal investment portfolio and its operating schedule which together minimize the cost of meeting site service, e.g., cooling, heating, requirements. Past studies have considered combined heat and power (CHP) technologies. Methods and software have been developed to solve this problem, finding optimal solutions which take simultaneity into account. This project aims to extend on those prior capabilities in two key dimensions. In this research storage technologies have been added as well as power quality and reliability (PQR) features that provide the ability to value the additional indirect reliability benefit derived from Consortium for Electricity Reliability Technology Solutions (CERTS) Microgrid capability. This project is intended to determine how attractive on-site generation becomes to a medium-sized commercial site if economical storage (both electrical and thermal), CHP opportunities, and PQR benefits are provided in addition to avoiding electricity purchases. On-site electrical storage, generators, and the ability to seamlessly connect and disconnect from utility service would provide the facility with ride-through capability for minor grid disturbances. Three building types in both California and New York are assumed to have a share of their sensitive electrical load separable. Providing enhanced service to this load fraction has an unknown value to the facility, which is estimated analytically. In summary, this project began with 3 major goals: (1) to conduct detailed analysis to find the optimal equipment combination for microgrids at a few promising commercial building hosts in the two favorable markets of California and New York; (2) to extend the analysis capability of DER-CAM to include both heat and electricity storage; and (3) to make an initial effort towards adding consideration of PQR into the capabilities of DER-CAM.

Stadler, Michael; Marnay, Chris; Siddiqui, Afzal; Lai, Judy; Coffey, Brian; Aki, Hirohisa

2008-12-01

385

Conductive heat flow anomalies over a hot spot in a moving medium  

Microsoft Academic Search

In the model the hot spot is represented by a point source of heat in an infinite half space moving uniformly in the x direction with velocity U (z is positive downward; y is horizontal and normal to motion). Only steady state conductive heat transfer is considered. The upper boundary condition, zero surface temperature, is satisfied by addition of a

Francis S. Birch

1975-01-01

386

BWR spent fuel storage cask performance test. Volume 1. Cask handling experience and decay heat, heat transfer, and shielding data  

SciTech Connect

This report documents a heat transfer and shielding performance test conducted on a Ridihalgh, Eggers and Associates REA 2023 boiling water reactor (BWR) spent fuel storage cask. The testing effort consisted of three parts: pretest preparations, performance testing, and post-test activities. Pretest preparations included conducting cask handling dry runs and characterizing BWR spent fuel assemblies from Nebraska Public Power District's Cooper Nuclear Station. The performance test matrix included 14 runs consisting of two loadings, two cask orientations, and three backfill environments. Post-test activities included calorimetry and axial radiation scans of selected fuel assemblies, in-basin sipping of each assembly, crud collection, video and photographic scans, and decontamination of the cask interior and exterior.

McKinnon, M.A.; Doman, J.W.; Tanner, J.E.; Guenther, R.J.; Creer, J.M.; King, C.E.

1986-02-01

387

The application of Mg-based metal-hydrides as heat energy storage systems  

Microsoft Academic Search

Mg-based metal hydride systems are potential high temperature heat storage media. In this paper the features and possibilities of the systems Mg\\/MgH2, Mg–Ni\\/Mg2NiH4, Mg–Fe\\/Mg2FeH6 and Mg–Co–H are discussed. All the materials show cyclic stability in certain temperature ranges. The thermal energy which is released by these systems covers a temperature range from 250°C to 550°C in which high thermal energy

A Reiser; B Bogdanovi?; K Schlichte

2000-01-01

388

Testing thermocline filler materials and molten-salt heat transfer fluids for thermal energy storage systems used in parabolic trough solar power plants.  

SciTech Connect

Parabolic trough power systems that utilize concentrated solar energy to generate electricity are a proven technology. Industry and laboratory research efforts are now focusing on integration of thermal energy storage as a viable means to enhance dispatchability of concentrated solar energy. One option to significantly reduce costs is to use thermocline storage systems, low-cost filler materials as the primary thermal storage medium, and molten nitrate salts as the direct heat transfer fluid. Prior thermocline evaluations and thermal cycling tests at the Sandia National Laboratories' National Solar Thermal Test Facility identified quartzite rock and silica sand as potential filler materials. An expanded series of isothermal and thermal cycling experiments were planned and implemented to extend those studies in order to demonstrate the durability of these filler materials in molten nitrate salts over a range of operating temperatures for extended timeframes. Upon test completion, careful analyses of filler material samples, as well as the molten salt, were conducted to assess long-term durability and degradation mechanisms in these test conditions. Analysis results demonstrate that the quartzite rock and silica sand appear able to withstand the molten salt environment quite well. No significant deterioration that would impact the performance or operability of a thermocline thermal energy storage system was evident. Therefore, additional studies of the thermocline concept can continue armed with confidence that appropriate filler materials have been identified for the intended application.

Kelly, Michael James; Hlava, Paul Frank; Brosseau, Douglas A.

2004-07-01

389

Cooling of a pulsed energy-storage rep-rated Yb:YAG laser disk by heat sink  

NASA Astrophysics Data System (ADS)

The thermal effect is one of the biggest obstacles that the solid laser heads into high power and high beam quality. The characteristic of heat-storage mechanism and heat conduct behavior about the phase change material is studied in this text. Inserting appropriate metal pieces or graphite can elevate the conduct coefficient of phage change material effectively. Researches are performed on the cooling characteristics of the pulsed energy - storage rep-rated large-aperture end-pumped Yb:YAG disk laser with non-uniform heat source by forced convection cooling in a narrow passage and heat sink. Two cooling schemes are selected; they are forced convection cooling with water, heat sink with phase change material. Numerical simulations are conducted to investigate the temperature and thermal stress distributions of the laser disk. The calculation results show that the cooling scheme using phase change material heat sink is the best, which may practicality applied.

Chen, Lin; He, Shaobo; Cao, Dingxiang; Liu, Jianguo; Liu, Yong; Chen, Yuanbin; Li, Mingzhong; Jing, Feng

2008-12-01

390

Extended development of a sodium hydroxide thermal energy storage module  

Microsoft Academic Search

The post-test evaluation of a single heat exchanger sodium hydroxide thermal energy storage module for use in solar electric generation is reported. Chemical analyses of the storage medium used in the experimental model are presented. The experimental verification of the module performance using an alternate heat transfer fluid, Caloria HT-43, is described. Based on these results, a design analysis of

R. E. Rice; P. E. Rowny; B. M. Cohen

1980-01-01

391

Second law optimization of a sensible heat thermal energy storage system with a distributed storage element. Part 2; Presentation and interpretation of results  

Microsoft Academic Search

This paper explores the behavior of a flat- slab, sensible heat thermal energy storage system, the physical design and operation of which have been optimized to minimize the production of entropy by thermodynamic irreversibilities. This part includes a description of the numerical model and the presentation and interpretation of the results of a system optimization study. The major results of

M. J. Taylor; R. J. Krane; J. R. Parsons

1991-01-01

392

Determination of body heat storage: how to select the weighting of rectal and skin temperatures for clothed subjects  

Microsoft Academic Search

Two methods of estimating body heat storage were compared under differing conditions of clothing and acclimation to heat. Sixteen male subjects underwent 6 consecutive days or two 6-day periods, separated by a 1-day rest period of heat acclimation, exercising 60 min · day?1 at 45%–55% of maximal aerobic power in a hot, dry environment (dry bulb temperature 40°C; relative humidity

Yukitoshi Aoyagi; Tom M. McLellan; Roy J. Shephard

1996-01-01

393

Flow and conjugate heat exchange in a rotating cavity with an axially supplied working medium  

NASA Astrophysics Data System (ADS)

Numerical modeling of the turbulent flow and conjugate heat exchange in a cavity bounded by a rotor and a stator is carried out. Coupled thermal calculations are based on the unsteady heat-conduction equation describing the temperature distribution within a solid and Reynolds-averaged Navier-Stokes equations closed using the k-? turbulence model, which allow calculation of the velocity, pressure, and temperature distributions in the fluid-filled region. The space-time distributions of the temperature and the heat flux on the metal-fluid interface are obtained in two- and three-dimensional formulations of the problem on a structured and an unstructured grid.

Volkov, K. N.

2011-03-01

394

Behavior of Propagation and Heating Due to Absorption of Ultrasound in Medium  

Microsoft Academic Search

Recently, ultrasound waves have been put to practical use not only in diagnostic equipment but also in thermotherapy that uses the effect of ultrasound waves in a living body. The analysis of temperature rise due to the absorption of ultrasound in a soft tissue medium is an important analyzing object for the clarification of the effect of ultrasound waves in

Chiaki Yamaya; Hiroshi Inoue

2006-01-01

395

Thermal storage in ammonium alum/ammonium nitrate eutectic for solar space heating applications  

SciTech Connect

Ammonium alum and ammonium nitrate in the weight ratio of 1:1 form a eutectic that melts at 53 C and solidifies at 48 C. The thermophysical properties of this eutectic were measured in detail and the eutectic was found to have properties desirable for energy storage for solar space heating applications. The eutectic was encapsulated in 0.0254-m diameter high-density polyethylene (HDPE) balls and packed into a cylindrical bed in a scale model for testing its heat transfer characteristics when exposed to an air flow. Test results indicate that the thermal extraction efficiency of the model was 89% with an uncertainty of {+-} 8.0%. The packed bed had a Stanton number value in close agreement with that predicted with an empirical equation for sensible heat extraction from the eutectic in the solid phase. This Stanton number was increased by about 74% for sensible heat extraction from the eutectic in the liquid phase, a phenomenon not previously reported in the literature.

Jotshi, C.K.; Hsieh, C.K.; Goswami, D.Y.; Klausner, J.F.; Srinivasan, N. [Univ. of Florida, Gainesville, FL (United States). Dept. of Mechanical Engineering

1998-02-01

396

Tree-shaped fluid flow and heat storage in a conducting solid  

NASA Astrophysics Data System (ADS)

This paper documents the time-dependent thermal interaction between a fluid stream configured as a plane tree of varying complexity embedded in a conducting solid with finite volume and insulated boundaries. The time scales of the convection-conduction phenomenon are identified. Two-dimensional and three-dimensional configurations are simulated numerically. The number of length scales of the tree architecture varies from one to four. The results show that the heat transfer density increases, and the time of approach to equilibrium decreases as the complexity of the tree designs increases. These results are then formulated in the classical notation of energy storage by sensible heating, which shows that the effective number of heat transfer units increases as the complexity of the tree design increases. The complexity of heat transfer designs in many applications is constrained by first cost and operating cost considerations. This work provides a fundamental basis for objective evaluation of cost and performance tradeoffs in thermal design of energy systems with complexity as an unconstrained parameter that can be actively varied over a broad range to determine the optimum system design.

Combelles, L.; Lorente, S.; Anderson, R.; Bejan, A.

2012-01-01

397

Analysis of Fluid Flow and Heat Transfer in a Liquid Hydrogen Storage Vessel for Space Applications  

NASA Astrophysics Data System (ADS)

This paper presents a systematic analysis of fluid flow and heat transfer in a liquid hydrogen storage vessel for both earth and space applications. The study considered a cylindrical tank with elliptical top and bottom. The tank wall is made of aluminum and a multi-layered blanket of cryogenic insulation (MLI) has been attached on the top of the aluminum. The tank is connected to a cryocooler to dissipate the heat leak through the insulation and tank wall into the fluid within the tank. The cryocooler has not been modeled; only the flow in and out of the tank to the cryocooler system has been included. The primary emphasis of this research has been the fluid circulation within the tank for different fluid distribution scenario and for different level of gravity to simulate potential earth and space based applications. The equations solved in the liquid region included the conservation of mass, conservation of energy, and conservation of momentum. For the solid region only the heat conduction equation was solved. The steady-state velocity, temperature, and pressure distributions were calculated for different inlet positions, inlet velocities, and for different gravity values. The above simulations were carried out for constant heat flux and constant wall temperature cases. It was observed that a good flow circulation could be obtained when the cold entering fluid was made to flow in radial direction and the inlet opening was placed close to the tank wall.

Mukka, Santosh K.; Rahman, Muhammad M.

2004-02-01

398

Free convection boundary layers on a vertical surface in a heat-generating porous medium  

NASA Astrophysics Data System (ADS)

The natural convection boundary-layer flow on a solid vertical surface with heat generated within the boundary layer at a rate proportional to (T - T{infty})p (p [?] 1) is considered. The surface is held at the ambient temperature T{infty} except near the leading edge where it is held at a temperature above ambient. The behaviour of the flow as it develops from the leading edge is examined and is seen to become independent of the initial heat input; however, it does depend strongly on the exponent p. For 1 [?] p [?] 2, the local heating eventually dominates at large distances and there is a convective flow driven by this mechanism. For p [?] 4, the local heating does not have a significant effect, the fluid temperature remains relatively small throughout and the heat transfer dies out through a wall jet flow. For 2 < p < 4, the local heating has a significant effect at relatively small distances, with a thermal runaway developing at a finite distance along the surface.

Mealey, L.; Merkin, J. H.

2008-02-01

399

The contact heat conductance at diamond-OFHC copper interface with GaIn eutectic as a heat transfer medium  

SciTech Connect

Results of an experimental study of the contact heat conductance across a single diamond crystal interface with OFHC copper (Cu) are reported. Gallium-indium (GaIn) eutectic was used as an interstitial material. Contact conductance data are important in the design and the prediction of the performance of x-ray diamond monochromators under high-heat-load conditions. Two sets of experiments were carried out. In one, the copper surface in contact with diamond was polished and then electroless plated with 1 {mu}m of nickel, while in the other, the copper contact surface was left as machined. Measured average interface heat conductances are 44.7 {plus_minus}8 W/cm{sup 2}{minus}K for nonplated copper and 23.0 {plus_minus}3 W/cm{sup 2}{minus}K for nickel-plated copper. For reference, the thermal contact conductances at a copper-copper interface (without diamond) were also measured, and the results are reported. A typical diamond monochromator, 0.2 mm thick, will absorb about 44 W under a standard undulator beam at the Advanced Photon Source. The measured conductance for nickel-plated copper suggests that the temperature drop across the interface of diamond and nickel-plated copper, with a 20 mm{sup 2} contact area, will be about 10{degree}C. Therefore temperature rises are rather modest, and the accuracy of the measured contact conductances presented here are sufficient for design purposes.

Assoufid, L.; Khounsary, A.M.

1996-01-01

400

Monitoring the succession of the biota grown on a selective medium for pseudomonads during storage of minced beef with molecular-based methods.  

PubMed

In the present study, the succession of the biota grown on a selective medium for pseudomonads (pseudomonas agar based medium - PAB) during the storage of meat under different conditions was monitored. Thus, minced beef was stored aerobically and under modified atmosphere packaging in the presence (MAP+) and absence (MAP-) of oregano essential oil at 0, 5, 10 and 15 °C. A total of 267 pure cultures were recovered from PAB throughout the storage period and subjected to PCR-Denaturing gradient gel electrophoresis (PCR-DGGE) for their differentiation. In parallel, the direct analysis of the whole cultivable community (WCC) from the same medium was applied. These two approaches were used in order to indicate the lack of selectivity. Fifteen different DGGE fingerprints were obtained after PCR - DGGE analysis of the isolates, which were assigned to Pseudomonas putida (3 fingerprints), Pseudomonas fragi and Pseudomonas fluorescens, Pseudomonas spp., Serratia liquefaciens (2), Citrobacter freundii, Serratia grimesii, Hafnia alvei (3), Rahnella spp. and Morganella morganii. Twelve of them occurred during the direct analysis of the WCC. The biota succession found to be affected from the different storage conditions. However, the outcome of the two strategies was quite different, which is leading to the use of different appropriated molecular approaches in order to widen the knowledge of bacterial succession of meat. PMID:23498179

Doulgeraki, Agapi I; Nychas, George-John E

2012-12-03

401

Solar energy storage via a closed-loop chemical heat pipe  

SciTech Connect

The performance of a solar chemical heat pipe was studied using CO[sub 2] reforming of methane as the vehicle for storage and transport of solar energy. The endothermic reforming reaction was carried out with a reactor packed with a supported rhodium catalyst and heated by the concentrated solar flux from the Schaeffer solar furnace at the Weizmann Institute (Rehovot, Israel). The maximum absorbed power was 8.5 kW. The reforming was run under variable insolation conditions, including partly cloudy days. The flux input was regulated by opening the doors of the concentrator building. The product gas temperature followed a predetermined set point that automatically controlled the flow of reactants to ensure constant composition of the reformer products. The exothermic methanation reaction was run in a multistage methanator filled with the same Rh catalyst and fed with the products from the reformer. High conversions were achieved for both reactions. In the closed-loop mode, the products from the reformer and from the methanator were compressed into separate storage tanks. The two reactions were run consecutively, and the whole process was repeated for over 60 cycles. The overall performance of the closed loop was satisfactory; scaleup work is in progress. 7 refs., 10 figs., 3 tabs.

Levy, M.; Levitan, R.; Rosin, H.; Rubin, R. (Weizmann Inst. of Science, Rehovot (Israel))

1993-02-01

402

OPTIMIZATION OF INTERNAL HEAT EXCHANGERS FOR HYDROGEN STORAGE TANKS UTILIZING METAL HYDRIDES  

SciTech Connect

Two detailed, unit-cell models, a transverse fin design and a longitudinal fin design, of a combined hydride bed and heat exchanger are developed in COMSOL{reg_sign} Multiphysics incorporating and accounting for heat transfer and reaction kinetic limitations. MatLab{reg_sign} scripts for autonomous model generation are developed and incorporated into (1) a grid-based and (2) a systematic optimization routine based on the Nelder-Mead downhill simplex method to determine the geometrical parameters that lead to the optimal structure for each fin design that maximizes the hydrogen stored within the hydride. The optimal designs for both the transverse and longitudinal fin designs point toward closely-spaced, small cooling fluid tubes. Under the hydrogen feed conditions studied (50 bar), a 25 times improvement or better in the hydrogen storage kinetics will be required to simultaneously meet the Department of Energy technical targets for gravimetric capacity and fill time. These models and methodology can be rapidly applied to other hydrogen storage materials, such as other metal hydrides or to cryoadsorbents, in future work.

Garrison, S.; Tamburello, D.; Hardy, B.; Anton, D.; Gorbounov, M.; Cognale, C.; van Hassel, B.; Mosher, D.

2011-07-14

403

Heat and mass transfer in magneto-biofluid flow through a non-Darcian porous medium with Joule effect  

NASA Astrophysics Data System (ADS)

In the present study, a mathematical model for the hydromagnetic non-Newtonian biofluid flow in the non-Darcy porous medium with Joule effect is proposed. A uniform magnetic field acts perpendicularly to the porous surface. The governing nonlinear partial differential equations are transformed into linear ones which are solved numerically by applying the explicit finite difference method. The effects of various parameters, like Reynolds number and hydro-magnetic, Forchheimer, and Darcian parameters, Prandtl, Eckert, and Schmidt numbers, on the velocity, temperature, and concentration are presented graphically. The results of the study can find applications in surgical operations, industrial material processing, and various heat transfer processes.

Sharma, B. K.; Mishra, A.; Gupta, S.

2013-07-01

404

A low-temperature heat storage system utilizing mixtures of magnesium salt hydrates and ammonium nitrate  

SciTech Connect

The heat storage system based on mixtures of salt hydrates and anhydrous salts desjribed in previous articles has been applied to Mg(NO/sub 3/)/sub 2/.6H/sub 2/O and MgCI/sub 2/. 6H/sub 2/O (alone or in eutectic mixtures), added with NH/sub 4/NO/sub 3/. Calorimetric measurements showed that in the temperature range 25-60/sup 0/C, Mg(NO/sub 3/). 6H/sub 2/O allows a Thermal Energy Storage (TES) capacity of about 56 kcal/kg (equivalent to 86 kcal/liter), which is slightly lower than the values previously recorded with ammonium alum. When the maximum temperature was lowered to 55/sup 0/ and to 50/sup 0/C, in order to be closer to the peak-efficiency of commercial flat-plate collectors, the best results were obtained, respectively, with Mg(NO/sub 3/)/sub 2/ .6H/sub 2/O and with the eutectic mixture Mg(NO/sub 3/)/sub 2/. 6H/sub 2/O - MgCI/sub 2/. 6H/sub 2/O, both added with NH/sub 4/NO/sub 3/. The mixtures of the aforementioned magnesium salts and ammonium nitrate do not show any significant efficiency reduction after many thermal cycles, and at the present stage of the research, they may be considered the most suitable for obtaining heat storages in the temperature range of commercial solar collectors.

Vaccarino, C.; Barbaccia, A.; Frusteri, F.; Galli, G.; Maisano, G.

1985-02-01

405

Heat transfer in free convection and forced, laminar flow in vertical tubes, considering temperature dependent medium characteristics  

NASA Astrophysics Data System (ADS)

The local and average heat transfer coefficients in the laminar flow in vertical tubes, which are significantly better than in the case of horizontal flow, were calculated. The numerical calculation was performed for a heated upward flow and a cooled downward flow. Navier-Stokes equations, energy equation, continuity equation, medium characteristics functions and the simplified equation system with boundary conditions are deduced. The similarity theory was applied to obtain the required set of characteristic values. The numerical method and the Runge-Kutta-Fehlberg time integration are outlined. The correlations of the analytical boundary solutions concord with other analytical solutions and with experimental data. The systematic, but acceptable errors are partly due to insufficient discretization.

Kessler, Hans-Jochen

1988-06-01

406

Towards a holistic view of the heating and cooling of the intracluster medium  

NASA Astrophysics Data System (ADS)

X-ray clusters are conventionally divided into two classes: `cool core' (CC) clusters and `non-cool core' (NCC) clusters. Yet relatively little attention has been given to the origins of this apparent dichotomy and, in particular, to the energetics and thermal histories of the two classes. We develop a model for the entropy profiles of clusters starting from the configuration established by gravitational shock heating and radiative cooling. At large radii, gravitational heating accounts for the observed profiles and their scalings well. However, at small and intermediate radii, radiative cooling and gravitational heating cannot be combined to explain the observed profiles of either CC or NCC clusters. The inferred entropy profiles of NCC clusters require that material is `pre-heated' prior to cluster collapse in order to explain the absence of low-entropy (cool) material in these systems. We show that a similar modification is also required in CC clusters in order to match their entropy profiles at intermediate radii. In CC clusters, this modification is unstable, and an additional process is required to prevent cooling below a temperature of a few keV. We show that this can be achieved by adding a self-consistent active galactic nuclei (AGN) feedback loop in which the lowest entropy, most rapidly cooling material is heated and rises buoyantly to mix with material at larger radii. The resulting model does not require fine-tuning and is in excellent agreement with a wide variety of observational data from Chandra and XMM-Newton, including entropy and gas density profiles, the luminosity-temperature relation and high-resolution spectra. The spread in cluster core morphologies is seen to arise because of the steep dependence of the central cooling time on the initial level of pre-heating. Some of the other implications of this model are briefly discussed.

McCarthy, I. G.; Babul, A.; Bower, R. G.; Balogh, M. L.

2008-05-01

407

Transient forced convection heat transfer from a circular cylinder embedded in a porous medium  

SciTech Connect

Studies of the transient heat transfer past a circular cylinder in a steady-state viscous flow are presented for some fluid saturated fibrous porous media. Numerical results have been obtained according to the Darcy-Brinkman model by means of the finite element method. Analysis of the influence of the Darcy and Peclet numbers on the mean Nusselt number exhibits the successive conduction, transition and convection regimes. The duration necessary to reach the steady-state convection heat transfer appears as a function of the Peclet and Darcy numbers.

Thevenin, J. [Universite Pierre et Marie Curie, Paris (France). Modelisation des Transferts Thermiques

1995-07-01

408

The effect of a covert manipulation of ambient temperature on heat storage and voluntary exercise intensity.  

PubMed

The modulation of sub-maximal voluntary exercise intensity during heat stress has been suggested as a behavioral response to maintain homeostasis; however, the relationship between thermophysiological cues and the associated response remains unclear. Awareness of an environmental manipulation may influence anticipatory planning before the start of exercise, making it difficult to isolate the dynamic integration of thermophysiological afferents during exercise itself. The purpose of the present study was to examine the direct real-time relationship between thermophysiological afferents and the behavioral response of voluntary exercise intensity. Participants were tasked with cycling at a constant rating of perceived exertion while ambient temperature (T(a)) was covertly changed from 20 °C to 35 °C and then back to 20 °C at 20-minute intervals. Overall, power output (PO) and heat storage, quantified using repeated measures ANOVA, changed significantly over 20-minute intervals (135 ± 39 W, 133 ± 46 W, 120 ± 45 W; 52.35 ± 36.15 W·m(-2), 66.34 ± 22.02 W·m(-2), -66.53 ± 56.01 W·m(-2)). The synchronicity of PO fluctuations with changes in thermophysiological status was quantified using Auto-Regressive Integrated Moving Average (ARIMA) time series analysis. Fluctuations in PO were not synchronized in real time with changes in T(a); heat storage; rectal, skin, or mean body temperature; or sweat rate (stationary-r(2) ? 0.10 and Ljung-Box statistic > 0.05 for all variables). We conclude that, while the thermal environment affects physiological responses and voluntary power output while cycling at a constant perceived effort, the behavioral response of voluntary exercise intensity did not depend on a direct response to real-time integration of thermal afferent inputs. PMID:22226992

Hartley, Geoffrey L; Flouris, Andreas D; Plyley, Michael J; Cheung, Stephen S

2011-12-29

409

Effect of Viscous Dissipation and Thermal Radiation on Heat Transfer over a Non-Linearly Stretching Sheet Through Porous Medium  

NASA Astrophysics Data System (ADS)

In this present paper, we have discussed the effects of viscous dissipation and thermal radiation on heat transfer over a non-linear stretching sheet through a porous medium. Usual similarity transformations are considered to convert the non-linear partial differential equation of motion and heat transfer into ODE's. Solutions of motion and heat transfer are obtained by the Runge-Kutta integration scheme with most efficient shooting technique. The graphical results are presented to interpret various physical parameters of interest. It is found that the velocity profile decreases with an increase of the porous parameter asymptotically. The temperature field decreases with an increase in the parametric values of the Prandtl number and thermal radiation while with an increase in parameters of the Eckert number and porous parameter, the temperature field increases in both PST (power law surface temperature) and PHF (power law heat flux) cases. The numerical values of the non-dimensional wall temperature gradient and wall temperature are tabulated and discussed.

Nandeppanavar, M. M.; Siddalingappa, M. N.

2013-06-01

410

A magnetoacoustic autowave pulse in a heat-releasing ionized gaseous medium  

NASA Astrophysics Data System (ADS)

An equation describing the evolution of fast and slow magnetoacoustic waves in a heat-releasing completely ionized gas has been obtained. The shape and parameters of the magnetoacoustic pulse that is an automodel solution of this equation under conditions of magnetoacoustic instability have been determined.

Zavershinsky, D. I.; Molevich, N. E.

2013-08-01

411

Heat treatment of hot-worked P\\/M medium-manganese steels  

Microsoft Academic Search

The authors explore the possibility of improving the mechanical properties of hot-worked manganese steels alloyed with nominal amounts of molybdenum, tungsten, vanadium, and silicon by quenching performed directly after high-temperature thermomechanical processing and by additional heat treatment. The hot working was performed, using sintered blanks, by hot compression and hot extrusion. Data are given on tensile strength, fatigue limit, impact

K. E. Ananyan; V. Yu. Dorofeev; V. I. Chumakov

1987-01-01

412

Temperature distribution in a uniform medium heated by linear absorption of a Gaussian light beam  

Microsoft Academic Search

The linear-diffusion equation is considered for a positive half-space with heat sources represented by Gaussian functions in the transverse plane and by exponential decay along the longitudinal axis. The exact solution is presented as a single quadrature of the complementary error function (erfc). The approximate solution is suggested in the form of the product of two Gaussian functions and the

Pablo Loza; Roberto Ortega; Dmitri Kouznetsov

1994-01-01

413

A variational method for solving nonlinear coupled problems of heat transfer in an orthotropic medium  

Microsoft Academic Search

A variational method for solving nonlinear coupled heat trasfer problems is proposed which makes it possible to implement direct variational calculus with respect to both spatial coordinates and time and to obtain an integral estimate of the accuracy of the approximate solution. It is shown that an integral estimate of the accuracy of the approximate solution based on the variational

V. V. Chikovani; V. A. Khusnutdinov

1987-01-01

414

Heat transfer and parametric studies of an encapsulated phase change material based cool thermal energy storage system  

Microsoft Academic Search

This work investigates the transient behaviour of a phase change material based cool thermal energy storage (CTES) system\\u000a comprised of a cylindrical storage tank filled with encapsulated phase change materials (PCMs) in spherical container integrated\\u000a with an ethylene glycol chiller plant. A simulation program was developed to evaluate the temperature histories of the heat\\u000a transfer fluid (HTF) and the phase

M. Cheralathan; R. Velraj; S. Renganarayanan

2006-01-01

415

Effects of the number and distribution of fins on the storage characteristics of a cylindrical latent heat energy storage system: a numerical study  

NASA Astrophysics Data System (ADS)

A numerical study of the effects of the number and distribution of fins on the storage characteristics of a cylindrical latent heat energy storage system (LHESS) was conducted. Due to the low thermal conductivity of phase change materials (PCMs) used in LHESS, fins were added to the system to increase the rate of heat transfer and charging. Finite elements were used to implement the developed numerical method needed to study and solve for the phase change heat transfer (melting of PCM) encountered in a LHESS during charging. The effective heat capacity method was applied in order to account for the large amount of latent energy stored during melting of the PCM and the moving interface between the solid and liquid phases. The effects of increasing the number and distribution of fins on the melting rate of the PCM were studied for configurations having between 0 and 27 fins for heat transfer fluid (HTF) velocities of 0.05 and 0.5 m/s. Results show that the overall heat transfer rate to the PCM increases with an increase in the number of fins irrespective of the HTF velocity. It was also observed that the total amount of energy stored after 12 h increases nearly linearly with the addition of fins up to 12 fins; further addition of fins increasing the total energy stored by ever smaller amounts.

Ogoh, Wilson; Groulx, Dominic

2012-10-01

416

Effect of heat generation or absorption on thermophoretic free convection boundary layer from a vertical flat plate embedded in a porous medium  

Microsoft Academic Search

This paper is focused on the study of coupled heat and mass transfer by boundary-layer free convection over a vertical flat plate embedded in a fluid-saturated porous medium in the presence of thermophoretic particle deposition and heat generation or absorption effects. The governing partial differential equations are transformed into ordinary differential equations by using special transformations. The resulting similarity equations

Ali J. Chamkha; Ali F. Al-Mudhaf; Ioan Pop

2006-01-01

417

Analytical Solutions to the Near-Neutral Atmospheric Surface Energy Balance with and without Heat Storage for Urban Climatological Studies.  

NASA Astrophysics Data System (ADS)

Analytical solutions are presented to the near-neutral atmospheric surface energy balance with the new approach of including the participation of heat storage in the building substrate. Analytical solutions are also presented for the first time for the case without heat storage effect. By a linearization process, the governing equations are simplified to a set of time-dependent, linear, first-order equations from which explicit solutions are readily obtainable. The results compare well with those obtained by numerical solutions upon the set without linearization when applied to the tropical city of Kuala Lumpur, Malaysia.

Tso, C. P.; Chan, B. K.; Hashim, M. A.

1991-04-01

418

Critical heat flux in a vertical tube at low and medium pressures  

Microsoft Academic Search

This paper presents experimental CHF data obtained for vertical up flow in an 8 mm I.D. test section, for a wide range of exit qualities (5–75%) and exit pressures ranging from 5 to 40 bar. The experiments were carried out for heated lengths of 0.75, 1, 1.4, 1.8, 2.5 and 3.5 m. A number of different coordinate systems are used

A. Olekhnovitch; A. Teyssedou; A. Tapucu; P. Champagne; D. C. Groeneveld

1999-01-01

419

Solar energy and storage  

NASA Astrophysics Data System (ADS)

The contribution consists of two parts. The first one deals with the problem that substituting oil by solar energy implies also to find a long term storage for high quality energy. The conclusion of the rather general discussion is that solar high temperature chemistry, electrochemistry and photochemistry are probably the most important R&D fields to be emphasized in the future. In the second part mostly work done at EIR is presented. The topics sketched are remarks concerning underground heat storage, capacity determination for medium term (days to weeks) hot water storages, the energy density in latent heat storage and a few remarks to the problem of using the grid to store (or buffer) solar (photovoltaic) electricity.

Kesselring, P.

1982-11-01

420

Radiation heat transfer coefficients for a random void-solid medium with diffusely reflecting surfaces  

SciTech Connect

Radiant heat transport through the void spaces of a gas-solid system is generally important at higher temperatures, such as those encountered in catalytic dehydrogenation reactions or in cracking catalyst regeneration operations. Because of the difficulty of dealing with radiation within the complex bed geometry, the long range effects of scattering from particle to particle through the voids of the bed have not yet been included in any theory of radiation transport in porous solids. A variational principle has been formulated for the radiative and conductive heat transport through a thick random porous bed of void fraction and average pore diameter. The solid material is opaque with thermal conductivity, the gray pore wall surfaces are characterized by an emissivity {epsilon}, with diffusive scattering of all orders in (1-{epsilon}). A void radiation conductivity has been calculated for a model pore structure generated by randomly placed, freely overlapping solid spheres, all of the same radius. This conductivity is compared with corresponding results from kinetic theory, radiation heat transport, and experiments.

Tseng, J.W.C.; Wolf, J.R.; Strieder, W. (Notre Dame Univ., IN (USA). Dept. of Chemical Engineering)

1988-01-01

421

Performance of heat charge\\/discharge of magnesium nitrate hexahydrate and magnesium chloride hexahydrate mixture to a single vertical tube for a latent heat storage system  

Microsoft Academic Search

The authors focused on a mixture of magnesium nitrate hexahydrate as a base material and magnesium chloride hexahydrate as an additive to store and utilize urban waste heat from emerged co-generation systems, typically available at temperatures of 60–90 °C. The second paper revealed that this mixture has good thermal characteristics as a PCM for latent thermal energy storage. In this

K Nagano; K Ogawa; T Mochida; K Hayashi; H Ogoshi

2004-01-01

422

Phase change and heat transfer characteristics of a eutectic mixture of palmitic and stearic acids as PCM in a latent heat storage system  

Microsoft Academic Search

The phase change and heat transfer characteristics of a eutectic mixture of palmitic and stearic acids as phase change material (PCM) during the melting and solidification processes were determined experimentally in a vertical two concentric pipes energy storage system. This study deals with three important subjects. First is determination of the eutectic composition ratio of the palmitic acid (PA) and

Gülseren Baran; Ahmet Sari

2003-01-01

423

Fundamental heat-transfer processes related to phase-change thermal-storage media  

SciTech Connect

Research performed between June and December 1982 on fundamental heat transfer processes which occur in phase-change thermal storage systems is described. The research encompasses both freezing and melting, and includes both experiment and analysis. The experimental portion of the work in progress is concerned with phase change which occurs within a closed cylinder or tube. In separate but interrelated freezing and melting experiments, the effect of the inclination of the tube in the gravity field was investigated. For freezing, it was found that despite local variations, the global (i.e., surface-averaged) freezing rate was virtually independent of the inclination of the tube. On the other hand, for melting, different regimes characterized by different melting rates were encountered as a function of the tube inclination. The rate of melting is least when the tube is vertical. At moderate angles relative to the vertical, gravity presses the melting solid against the tube, thereby accelerating the rate at which melting occurs. Numerical solutions obtained with an implicit-explicit finite difference scheme were employed to explore the effects of solid-solid phase transitions on freezing which occurs on a plane wall or on the outside surface of a cylinder. Another focus of the work was to take account of heat transfer at the solid-liquid interface due to natural convection in the adjacent liquid melt. In the presence of interfacial convection, freezing ceases when a critical thickness of the solidified layer is attained. The greater the interfacial convection, the smaller is the critical thickness and the shorter is the time required for its attainment. The heat liberated by the solid-solid transition reduces the thickness of the solidified layer but increases the rate of heat extraction at the cooled wall.

Sparrow, E.M.

1982-12-01

424

A New Evaluation Method of Stored Heat Effect of Reinforced Concrete Wall of Cold Storage  

NASA Astrophysics Data System (ADS)

Today it has become imperative to save energy by operating a refrigerator in a cold storage executed by external insulate reinforced concrete wall intermittently. The theme of the paper is to get the evaluation method to be capable of calculating, numerically, interval time for stopping the refrigerator, in applying reinforced concrete wall as source of stored heat. The experiments with the concrete models were performed in order to examine the time variation of internal temperature after refrigerator stopped. In addition, the simulation method with three dimensional unsteady FEM for personal-computer type was introduced for easily analyzing the internal temperature variation. Using this method, it is possible to obtain the time variation of internal temperature and to calculate the interval time for stopping the refrigerator.

Nomura, Tomohiro; Murakami, Yuji; Uchikawa, Motoyuki

425

A3606LS - Improved-Lumped Formulations for Heat and Mass Transfer in Adsorbed Gas Storage  

NASA Astrophysics Data System (ADS)

The purpose of this study is to provide an improved-lumped formulation for simulating adsorbed gas storage operations. The approach is shown to reduce the original spatial-dependent PDEs to two time-dependent ODEs, as similar to the ones obtained using classical lumped-system analyses (CLSA), the main differences being an additional equation that is required for calculating the reservoir wall temperature, and modified Biot numbers. The average reservoir temperature is then calculated with the improved lumped formulation, using two different approximation schemes, and compared with the results of the CLSA and the one-dimensional formulation that originated all approximate lumped models. A case of slow discharge with negligible wall heat capacity is analyzed, and the results show that, even for a large Biot number, one of the proposed approximation schemes can reproduce the 1D results with reasonable accuracy, while the CLSA yields very different results.

Sphaier, L. A.; Jurumenha, D. S.

2012-11-01

426

Development of heat-storage building materials for passive-solar applications  

NASA Astrophysics Data System (ADS)

A heat storage building material to be used for passive solar applications and general load leveling within building spaces was developed. Specifically, PCM-filled plastic panels are to be developed as wallboard and ceiling panels. Three PCMs (CaCl2, 6H2O; Na2SO4, 10H2O; LiNO3, 3H2O are to be evaluated for use in the double walled, hollow channeled plastic panels. Laboratory development of the panels will include determination of filling and sealing techniques, behavior of the PCMs, container properties and materials compatibility. Testing will include vapor transmission, thermal cycle, dynamic performance, accelerated life and durability tests. In addition to development and testing, an applications analysis will be performed for specific passive solar applications. Conceptual design of a single family passive solar residence will be prepared and performance evaluated. Screening of the three PCM candidates is essentially complete.

Fletcher, J. W.

427

Computational approaches to aspect-ratio-dependent upper bounds and heat flux in porous medium convection  

NASA Astrophysics Data System (ADS)

Direct numerical simulation (DNS) has shown that Rayleigh-Bénard convection in a fluid-saturated porous medium self-organizes into narrowly spaced plumes at (ostensibly) asymptotically high values of the Rayleigh number Ra. In this Letter a combination of DNS and upper bound theory is used to investigate the dependence of the Nusselt number Nu on the domain aspect ratio L at large Ra. A novel algorithm is introduced to solve the optimization problems arising from the upper bound analysis, allowing for the best available bounds to be extended up to Ra?2.65×104. The dependence of the bounds on L(Ra) is explored and a "minimal flow unit" is identified.

Wen, Baole; Chini, Gregory P.; Dianati, Navid; Doering, Charles R.

2013-12-01

428

Lie group analysis and numerical solutions for non-Newtonian nanofluid flow in a porous medium with internal heat generation  

NASA Astrophysics Data System (ADS)

A mathematical model is presented and analysed for steady two-dimensional non-isothermal boundary layer flow from a heated horizontal surface which is embedded in a porous medium saturated with a non-Newtonian power-law nanofluid. It is assumed that the wall temperature and nanoparticle volume fraction vary nonlinearly with the axial distance. By applying appropriate group transformations, the governing transport equations are reduced to a system of coupled, nonlinear ordinary differential equations with associated boundary conditions. The reduced equations are then solved numerically using the Runge-Kutta-Fehlberg fourth-fifth-order numerical method with Maple 13 software. The effects of several thermophysical parameters including rheological power-law index, non-isothermal index, Lewis number, Brownian motion parameter, thermophoresis parameter, buoyancy ratio and internal heat generation/absorption parameter on the non-dimensional velocity, temperature, nanoparticle volume fraction (concentration) and also on the friction factor, heat and mass transfer rates are investigated. A comparison of the present results with the existing published results shows excellent agreement, verifying the accuracy of the present numerical code. The study finds applications in nano biopolymeric manufacturing processes and also thermal enhancement of energy systems employing rheological working fluids.

Jashim Uddin, Md; Yusoff, N. H. Md; Bég, O. Anwar; Izani Ismail, Ahamd

2013-02-01

429

Central receiver solar thermal power system, Phase 1. CDRL Item 2. Pilot plant preliminary design report. Volume V. Thermal storage subsystem. [Sensible heat storage using Caloria HT43 and mixture of gravel and sand  

Microsoft Academic Search

The proposed 100-MWe Commercial Plant Thermal Storage System (TSS) employs sensible heat storage using dual liquid and solid media for the heat storage in each of four tanks, with the thermocline principle applied to provide high-temperature, extractable energy independent of the total energy stored. The 10-MW Pilot Plant employs a similar system except uses only a single tank. The high-temperature

R. W. Jr. Hallet; R. L. Gervais

1977-01-01

430

Thermal conductivity and latent heat thermal energy storage characteristics of paraffin\\/expanded graphite composite as phase change material  

Microsoft Academic Search

This study aimed determination of proper amount of paraffin (n-docosane) absorbed into expanded graphite (EG) to obtain form-stable composite as phase change material (PCM), examination of the influence of EG addition on the thermal conductivity using transient hot-wire method and investigation of latent heat thermal energy storage (LHTES) characteristics of paraffin such as melting time, melting temperature and latent heat

Ahmet Sar?; Ali Karaipekli

2007-01-01

431

Verification of numerical simulation method for entropy generation of radiation heat transfer in semitransparent medium  

NASA Astrophysics Data System (ADS)

The numerical simulation method of radiative entropy generation in participating media presented by Caldas and Semiao [Entropy generation through radiative transfer in participating media: analysis and numerical computation. JQSRT 2005;96:423 37] is extended to analyze the radiative entropy generation in the enclosures filled with semitransparent media. A discrete ordinates method is used to solve radiative transfer equation and radiative entropy generation. Two different examples are employed to verify the numerical simulation method of radiative entropy generation in the enclosure. Numerical results of dimensionless radiative entropy generation of enclosure are identical to that of entire thermodynamics analysis for the enclosure system. This numerical simulation method can be used in the entropy generation analysis of high-temperature systems such as boilers and furnaces, in which radiation is the dominant mode of heat transfer.

Liu, L. H.; Chu, S. X.

2007-01-01

432

Heat and mass transfer in the process of movement of water drops in a high-temperature gas medium  

NASA Astrophysics Data System (ADS)

The heat and mass transfer in the process of movement of water drops in a high-temperature gas medium was numerically investigated. The regimes and conditions of formation of the zone of mutual influence of two drops were determined on the basis of an analysis of the temperature and concentration fields of the water vapor in the neighborhood of the trajectory of movement of the drops. The times of existence (complete evaporation) of one and two drops as a result of their interaction with the high-temperature products of combustion of a typical condensed liquid substance were compared. It has been established that only in the case where the distance between the two drops is small is the intensity of evaporation of water from them substantially lower than that of a single drop.

Vysokomornaya, O. V.; Kuznetsov, G. V.; Strizhak, P. A.

2013-01-01

433

Non-Darcy free convection in a thermally stratified porous medium along a vertical plate with variable heat flux  

NASA Astrophysics Data System (ADS)

Free convection along an impermeable vertical plate embedded in a thermally stratified, fluid-saturated porous medium is analyzed. The wall heat flux is varied in a power-law form. The non-Darcian effects, such as solid-boundary viscous resistances, high-flow-rate inertia forces, near wall nonuniform porosity distribution and thermal dispersion, have been considered in the present study. Due to the variation of porosity in the near wall region, the stagnant thermal conductivity also varies accordingly. The nonsimilar system of transformed equations is solved with Keller's Box method. It is shown that the thermal stratification effect and the higher value of the exponent m can increase the local Nusselt number. Also the non-Darcian and thermal dispersion effects significantly influence the velocity and temperature profiles and local Nusselt number.

Hung, C.-I.; Chen, C.-B.

434

Longterm Solar Heat Storage in an Underground Water Cistern Retrofitted with Thermal Insulation. Second Technical Progress Report.  

National Technical Information Service (NTIS)

The performance of the cistern was tested by measuring storage and surrounding soil temperatures over extended periods of time as heat was added from a solar collector (summer, fall, and winter) or environmental coolness was added (via cold air blown into...

W. L. Borst

1980-01-01

435

INTERACTIONS OF AVG, MCP AND HEAT TREATMENT ON APPLE FRUIT RIPENING AND QUALITY AFTER HARVEST AND COLD STORAGE  

Microsoft Academic Search

The effects of AVG, an inhibitor of ethylene synthesis, in combination with MCP or heat treatment (HT) on quality traits of several apple cultivars after harvest (AH) or cold storage (ACS), and the involvement of ethylene in the regulation of SDH activity during the last weeks of fruit development were studied. AVG was applied to Royal Gala, Lodi, Senshu, Redchief

Valeria Sigal-Escalada

2006-01-01

436

Encapsulated Fatty Acids in an Acrylic Resin as Shape-stabilized Phase Change Materials for Latent Heat Thermal Energy Storage  

Microsoft Academic Search

This article aims to prepare novel shape-stabilized phase change materials (PCMs) by encapsulating fatty acids (stearic acid [SA], palmitic acid [PA], and myristic acid [MA]) as a PCM in an acrylic resin (Eudragit E) as supporting material and to determine latent heat thermal energy storage (LHTES) properties. The maximum percentage of all fatty acids in the shape-stabilized PCMs was found

K. Kaygusuz; C. Alkan; A. Sari; O. Uzun

2008-01-01

437

Thermal reliability test of some fatty acids as PCMs used for solar thermal latent heat storage applications  

Microsoft Academic Search

The purpose of this study is to determine the thermal reliability of stearic acid, palmitic acid, myristic acid and lauric acid as latent heat energy storage materials with respect to various numbers of thermal cycles. The fatty acids, as phase change materials (PCMs), of industrial grade (purity between 90% and 97%) were subjected to accelerated thermal cycle tests. The differential

Ahmet Sar?

2003-01-01

438

Full-scale study of a building equipped with a multi-layer rack latent heat thermal energy storage system  

Microsoft Academic Search

Phase change material has been installed as a latent heat thermal energy storage system coupled with the ventilation system in an office building located in Lyon, France. The main purpose of this study is to determine if the phase change material system can guarantee the summer comfort of the occupants without energy-consuming cooling devices. Sensors have been set up, and

Julien Borderon; Joseph Virgone; Richard Cantin; Frédéric Kuznik

2011-01-01

439

Preliminary design study of a central solar heating plant with seasonal storage at the University of Massachusetts, Amherst  

Microsoft Academic Search

This report documents the design development and selection of the final preliminary design of a Central Solar Heating Plant with Seasonal Storage (CSHPSS) for the University of Massachusetts in Amherst (UMass). The effort has been performed by the Department of Mechanical Engineering at UMass under contract with the U.S. Department of Energy. Phase 1 of this project was directed at

D. S. Breger; J. E. Sunderland

1991-01-01

440

Analysis of community solar systems for combined space and domestic hot water heating using annual cycle thermal energy storage  

NASA Astrophysics Data System (ADS)

A simplified design procedure was examined for estimating the storage capacity and collector area for annual-cycle-storage, community solar heating systems in which 100% of the annual space heating energy demand is provided from the solar source for the typical meteorological year. Hourly computer simulations of the performance of these systems were carried out for 10 cities in the United States for 3 different building types and 4 community sizes. These permitted the use of design values for evaluation of a more simplified system sizing method. Results of this study show a strong correlation between annual collector efficiency and two major, location-specific, annual weather parameters: the mean air temperature during daylight hours and the total global insolation on the collector surface. Storage capacity correlates well with the net winter load, which is a measure of the seasonal variation in the total load, a correlation which appears to be independent of collector type.

Hooper, F. C.; McClenahan, J. D.; Cook, J. D.; Baylin, F.; Monte, R.; Sillman, S.

1980-01-01

441

AQUASTOR: A computer model for cost analysis of aquifer thermal energy storage coupled with district heating or cooling systems  

SciTech Connect

This paper discusses the capabilities and structure of the computer simulation model AQUASTOR. The model optimizes system design and calculates the life-cycle cost of an aquifer thermal energy storage (ATES) system coupled to a district heating (cooling) system. AQUASTOR has the flexibility to simulate a wide range of system configurations, with a large number of technical and economic parameters available for defining the energy storage and distribution systems. The model combines the technical characteristics of storage and distribution systems with financial and tax conditions for the entities operating the two systems into one techno-economic model. This provides the flexibility to individually or collectively evaluate the impact of different economic and technical parameters, assumptions, and uncertainties on the cost of providing district heating (cooling) with an ATES system.

Brown, D.R.; Huber, H.D.; Reilly, R.W.

1982-08-01

442

Heat Production and Storage Are Positively Correlated with Measures of Body Size/Composition and Heart Rate Drift during Vigorous Running  

ERIC Educational Resources Information Center

|The purposes of this study were to determine the relationships between: (a) measures of body size/composition and heat production/storage, and (b) heat production/storage and heart rate (HR) drift during running at 95 % of the velocity that elicited lactate threshold, which was determined for 20 healthy recreational male runners. Subsequently,…

Buresh, Robert; Berg, Kris; Noble, John

2005-01-01

443

The Influence of Return Loop Flow Rate on Stratification in a Vertical Hot Water Storage Tank Connected to a Heat Pump Water Heater  

Microsoft Academic Search

A temperature-controlled hot water heat pump was simulated using heating in a vertical, domestic hot water storage tank. The influence of the return loop flow rate on stratification was investigated experimentally. The return loop is the water line that supplies a long line of consumers with hot water, and returns colder water to the middle of the hot water storage

P. Meyer; P. J. A. Raubenheimer; E. Krueger

2000-01-01

444

Heat Production and Storage Are Positively Correlated with Measures of Body Size/Composition and Heart Rate Drift during Vigorous Running  

ERIC Educational Resources Information Center

The purposes of this study were to determine the relationships between: (a) measures of body size/composition and heat production/storage, and (b) heat production/storage and heart rate (HR) drift during running at 95 % of the velocity that elicited lactate threshold, which was determined for 20 healthy recreational male runners. Subsequently,…

Buresh, Robert; Berg, Kris; Noble, John

2005-01-01

445

Anisotropic charge and heat conduction through arrays of parallel elliptic cylinders in a continuous medium  

NASA Astrophysics Data System (ADS)

Arrays of circular pores in silicon can exhibit a phononic bandgap when the lattice constant is smaller than the phonon scattering length, and so have become of interest for use as thermoelectric materials, due to the large reduction in thermal conductivity that this bandgap can cause. The reduction in electrical conductivity is expected to be less, because the lattice constant of these arrays is engineered to be much larger than the electron scattering length. As a result, electron transport through the effective medium is well described by the diffusion equation, and the Seebeck coefficient is expected to increase. In this paper, we develop an expression for the purely diffusive thermal (or electrical) conductivity of a composite comprised of square or hexagonal arrays of parallel circular or elliptic cylinders of one material in a continuum of a second material. The transport parallel to the cylinders is straightforward, so we consider the transport in the two principal directions normal to the cylinders, using a self-consistent local field calculation based on the point dipole approximation. There are two limiting cases: large negative contrast (e.g., pores in a conductor) and large positive contrast (conducting pillars in air). In the large negative contrast case, the transport is only slightly affected parallel to the major axis of the elliptic cylinders but can be significantly affected parallel to the minor axis, even in the limit of zero volume fraction of pores. The positive contrast case is just the opposite: the transport is only slightly affected parallel to the minor axis of the pillars but can be significantly affected parallel to the major axis, even in the limit of zero volume fraction of pillars. The analytical results are compared to extensive FEA calculations obtained using Comsol™ and the agreement is generally very good, provided the cylinders are sufficiently small compared to the lattice constant.

Martin, James E.; Ribaudo, Troy

2013-04-01

446

HYDROMAGNETIC BOUNDARY LAYER FLOW AND HEAT TRANSFER IN VISCOELASTIC FLUID OVER A CONTINUOUSLY MOVING PERMEABLE STRETCHING SURFACE WITH NONUNIFORM HEAT SOURCE\\/SINK EMBEDDED IN FLUID-SATURATED POROUS MEDIUM  

Microsoft Academic Search

Analytical study for the problem of flow and heat transfer of electrically conducting viscoelastic fluid over a continuously moving permeable stretching surface with nonuniform heat source\\/sink in a fluid-saturated porous medium has been undertaken. The momentum and thermal boundary layer equations, which are partial differential equations, are converted into ordinary differential equations, by using suitable similarity transformation. The resulting nonlinear

M. Subhas Abel; Mahantesh M. Nandeppanavar; M. B. Malkhed

2010-01-01

447

Preparatory experiments on seasonal storage in earth of excess heat from greenhouse  

Microsoft Academic Search

An earth heat accumulator, directly beneath an experimental greenhouse, with possibilities for collecting excess solar heat by pumps and utilization of low temperature heat was investigated. Heat exchange with the accumulator is made by a system of buried polyethylene pipes. The heat accumulator was loaded by excess solar heat from the greenhouse, using heat pumps, during two summer months. A

M. Areskoug; P. Wigstroem

1980-01-01

448

Development of warmed-over flavour in ground turkey, chicken and pork meat during chill storage. A model of the effects of heating temperature and storage time.  

PubMed

The susceptibility towards development of warmed-over flavour (WOF) was investigated in meat from turkey and chicken breast and thigh, and from pork longissiums dorsi muscle. Ground meat samples from these five sources were heated for 30 min in a water bath at 60, 70 or 80C, and the samples were stored at 5C for 0-4 days. During storage, WOF was quantified by measurement of thiobarbituric-acid reactive substances (TBARS) and by sensory evaluations. The increase in TBARS was modelled for each type of meat at the different heating temperatures by a first-order reaction, and it was shown that a common rate constant could be used for all types of meat. The estimated maximum levels of TBARS in meat samples decreased in the following order: turkey thigh > chicken thigh > turkey breast > chicken breast > port. For each type of meat, the estimated maximum level of TBARS rose when the heating temperature increased in the range 60-80C. This temperature effect was particularly obvious for the chicken samples. Thus thigh and breast meat from chicken heated to 60C was almost stable against oxidation during storage. Results obtained by measurement of TBARS were in good agreement with the sensory evaluations. PMID:7605515

Mielche, M M

1995-03-01

449

Programming MOFs for water sorption: amino-functionalized MIL-125 and UiO-66 for heat transformation and heat storage applications.  

PubMed

Sorption-based heat transformation and storage appliances are very promising for utilizing solar heat and waste heat in cooling or heating applications. The economic and ecological efficiency of sorption-based heat transformation depends on the availability of suitable hydrophilic and hydrothermally stable sorption materials. We investigated the feasibility of using the metal-organic frameworks UiO-66(Zr), UiO-67(Zr), H2N-UiO-66(Zr) and H2N-MIL-125(Ti) as sorption materials in heat transformations by means of volumetric water adsorption measurements, determination of the heat of adsorption and a 40-cycle ad/desorption stress test. The amino-modified compounds H2N-UiO-66 and H2N-MIL-125 feature high heat of adsorption (89.5 and 56.0 kJ mol(-1), respectively) and a very promising H2O adsorption isotherm due to their enhanced hydrophilicity. For H2N-MIL-125 the very steep rise of the H2O adsorption isotherm in the 0.1 < p/p0 < 0.2 region is especially beneficial for the intended heat pump application. PMID:23864023

Jeremias, Felix; Lozan, Vasile; Henninger, Stefan K; Janiak, Christoph

2013-07-18

450

Thermal energy storage for solar power generation - State of the art  

NASA Astrophysics Data System (ADS)

High temperature storage for applications in solar-thermal electric systems is considered. Noting that thermal storage is in either the form of latent, sensible or chemically stored heat, sensible heat storage is stressed as the most developed of the thermal storage technologies, spanning direct heating of a storage medium from 120-1250 C. Current methods involve solids, packed beds, fluidized beds, liquids, hot water, organic liquids, and inorganic liquids and molten salts. Latent heat storage comprises phase-change materials that move from solid to liquid with addition of heat and liquid to solid with the removal of heat. Metals or inorganic salts are candidates, and the energy balances are outlined. Finally, chemical heat storage is examined, showing possible high energy densities through catalytic, thermal dissociation reactions.

Shukla, K. N.

1981-12-01

451

AQUASTOR: a computer model for cost analysis of aquifer thermal energy storage coupled with district heating or cooling systems  

SciTech Connect

This paper discusses the capabilities and mechanics of the computer simulation model AQUASTOR. The model optimizes system design and calculates the lifecycle cost of an aquifer thermal energy storage (ATES) system coupled to a district heating (cooling) system. AQUASTOR has the flexibility to simulate a wide range of system configurations, with a large number of technical and economic parameters available for defining the energy storage and distribution systems. AQUASTOR consists of two principal parts: an ATES supply submodel and a district heating (cooling) distribution submodel. The model combines the technical characteristics of supply and distribution systems with financial and tax model. This provides the flexibility to individually or collectively evaluate the impact of different economic and technical parameters, assumptions, and uncertainties on the cost of providing district heating (cooling) with an ATES system.

Brown, D.R.; Huber, H.D.; Reilly, R.W.

1982-01-01

452

Thermal inactivation of Bacillus cereus spores affected by the solutes used to control water activity of the heating medium.  

PubMed

The heat resistance of B. cereus spores (ATCC 7004, 4342 and 9818) over a wide temperature range (92-125 degrees C) in aqueous solutions of NaCl, LiCl, sucrose and glycerol at different water activities (1.00-0.71) was investigated. Sodium chloride in the heating medium tended to protect the spores of B. cereus against heat. The z-values increased significantly (P < 0.05) at and above a concentration of 4.0 M. The effects of LiCl were lower than those caused by the NaCl at the same a(w) values. An increase in z-values was observed. but the differences were only statistically significant (P<0.05) at the highest concentration tested (5.0 M). A concentration of sucrose 0.87 M caused in all cases a reduction in D-values, which was most pronounced for strains 4342 and 9818. With increasing concentration of sucrose ( > 0.87 M), the D-values showed an increase, although only those obtained for strain 4342 in sucrose solutions 2.22 M were higher than those found in pure water. The z-values were significantly higher (P < 0.05) when sucrose was added at concentrations above 1.42 M, except for strain 4342. When a(w) was lowered from 0.96 to 0.71 with glycerol, D-values obtained gradually increased, about 30, 50 and 60 fold for 4342, 7004 and 9818 strains, respectively. No significant effect on z-values were detected. PMID:10598115

Mazas, M; Martínez, S; López, M; Alvarez, A B; Martin, R

1999-12-01

453

Applications of Thermal Energy Storage to Process Heat Storage and Recovery in the Paper and Pulp Industry.  

National Technical Information Service (NTIS)

Applications of Thermal Energy Storage (TES) in a paper and pulp mill power house were studied as one approach to the transfer of steam production from fossil fuel boilers to waste fuel of (hog fuel) boilers. Data from specific mills were analyzed, and va...

J. H. Carr P. J. Hurley P. J. Martin

1978-01-01

454

Modular solar greenhouse with elevated overhead heat storage material and movable insulation barriers and method and system for solar heating of attached living space using thermostat-controlled air circulation for harvesting heat  

SciTech Connect

A modular solar greenhouse incorporates rigid curving frames overhead with screw and nut tracks for ease of assembly and east side and west side end modules and advantageously employs a thermally broken glazing system; that is, the exterior and interior portions of the aluminum frame extrusions are bonded together by strong plastic material and then the metal bridge is removed for thermally isolating the interior frame portion from the exterior portion. At least one overhead heat storage unit is carried by the rigid frames, with insulated roofing being located above and also being supported by the frames, so that low-angle solar radiation in the wintertime can travel directly into the upper region of the greenhouse below the roof for directly impinging upon and supplying heat energy to the thermal storage units. Movable, reflective insulation barriers or curtains are extendible for enclosing the solar greenhouse for retaining warmth resulting from stored solar heat energy in the overhead storage units during winter nights.

Holdridge, R.B.; Taff, D.C.; Yanda, W.F.

1984-07-31

455

The behavior of a long term heat storage system in connection with a wind energy converter (phase 1)  

NASA Astrophysics Data System (ADS)

The technical and economical feasibility of heating a museum on the Wasserkuppe mountain (950 m) in the Rhoen hills by wind energy is affirmed. It is possible to recover the capital cost within a period of 15 to 19 years if the service life of the wind energy converter (WEC) and of the heat storage system is between 20 and 30 years. At a maximum thermal load of 120 kW, the minimum cost will be achieved with a WEC power output of 120 kW and a two day storage system. This combination permits 60% of the heat demand to be covered by wind energy. The balance has to be supplied by conventional energy sources. The wind energy fraction of the total energy demand thus is about twice as high as the solar fraction in the case of solar heating systems and about 15% higher than the fraction of ambient heating energy in the case of electric heat pumps used in bivalent operation. The wind price per kWh is already comparable to that expected for the future large wind energy converters (GROWIAN) to be produced in series.

Auer, F.; Bley, H.; Mueller, M.

1982-04-01

456

Assessment of plant toxicity threshold of several heat transfer and storage fluids and eutectic salts  

SciTech Connect

Plant toxicity threshold levels of several heat transfer and storage fluids and eutectic salts were determined by using a modified Neubauer technique. Barley seed germination and seedling growth were used for the toxicity tests. The general order of toxicity of the fluids applied to three mineral soils was ethylene gloycol > Dow 200 much greater than Caloria HT43 > Therminol 66. The toxicity order of the fluids applied to an organic soil was ethylene glycol > Caloria HT43 > Dow 200 > Therminol 66. Thus, Therminol 66 was the least toxic among the fluids used. Among the eutectic salts tested Dupont HITEC was more toxic than 8.4 percent NaCl-86.3 percent NaNO/sub 3/-5.3 percent Na/sub 2/SO/sub 4/ mixture in three of the four soils used. In the fourth soil there was no apparent difference of toxicity between the two salt mixtures. Depending on the fluid and the salt mixture, the toxicity threshold levels for barley seedlings ranged from 4451 to 317,488 ppM in the soils used.

Nishita, H.

1980-10-01

457

Heat-storage characteristics of LongTan hydroelectric station’s building enclosure in China  

Microsoft Academic Search

The air rate is universally over-sized in underground hydroelectric stations causing energy to be wasted. Therefore, it is necessary to determine the right design heat load of air conditioning. This paper presents an analysis of the heat absorption and heat emission of the building enclosure of LongTan underground hydroelectric station. The results show that the heat adsorption and heat emission

H. M Liu; Z. W Lian; X. J Ye

2003-01-01

458

Advanced High-Temperature Molten-Salt Storage Research.  

National Technical Information Service (NTIS)

We are researching advanced high-temperature molten-salt thermal storage for use in direct absorption receiver and thermal storage (DARTS) solar thermal systems. A molten salt at 900 exp 0 C or higher is both the receiver heat transfer medium and the stor...

R. J. Copeland R. T. Coyle

1983-01-01

459

Molten Salt-Carbon Nanotube Thermal Energy Storage for Concentrating Solar Power Systems.  

National Technical Information Service (NTIS)

We demonstrated that adding nanoparticles to a molten salt would increase its utility as a thermal energy storage medium for a concentrating solar power system. Specifically, we demonstrated that we could increase the specific heat of nitrate and carbonat...

A. Padmanaban D. Malik F. Little J. Luo M. Betts M. Schuller Q. Shao S. Shankar W. Zhong

2012-01-01

460

Numerical analysis of heat and mass transfer during absorption of hydrogen in metal hydride based hydrogen storage tanks  

Microsoft Academic Search

In this paper, hydriding in a cylindrical metal hydride hydrogen storage tank containing HWT5800 (Ti0.98Zr0.02V0.43Fe0.09Cr0.05Mn1.5) is numerically studied with a two-dimensional mathematical model. The heat and mass transfer of this model is computed by finite difference method. The effects of supply pressure, cooling fluid temperature, overall heat transfer coefficient and height to the radius ratio of the tank (H\\/R) on

Jianhua Ye; Lijun Jiang; Zhinian Li; Xiaopeng Liu; Shumao Wang; Xinyu Li

2010-01-01

461

Effects of xylooligosaccharides and sugars on the functionality of porcine myofibrillar proteins during heating and frozen storage  

Microsoft Academic Search

The gel properties of mixed gels of salt-soluble proteins (SSP) and xylooligosaccharides (XOS) or other sugars were investigated. Furthermore, the water-holding capacity, synaeresis, and protein surface hydrophobicity of heated SSP\\/sugar mixed gels under frozen storage were evaluated. Addition of XOS and sugars lowered expressible moisture and thus elevated the water-holding capacity of mixed gels. The protein surface hydrophobicity (RSo) of

Yi-Te Chou; Kuo-Wei Lin

2010-01-01

462

Measurements of the gas-particle convective heat transfer coefficient in a packed bed for high-temperature energy storage  

Microsoft Academic Search

Experimental measurements of the forced convection gas-particle heat transfer coefficient in a packed bed, high-temperature, thermal energy storage system were performed using a custom-made experimental facility. Special attention was paid to the application of uncertainty analysis (a very important concept in experimentation). General and detailed uncertainty analyses were carried out, which identified the choices that were made in the experimental

Emmanuel C. Nsofor; George A. Adebiyi

2001-01-01

463

The capric and lauric acid mixture with chemical additives as latent heat storage materials for cooling application  

Microsoft Academic Search

The mixture of capric acid and lauric acid (C-L acid), with the respective mole composition of 65% and 35%, is a potential phase change material (PCM). Its melting point of 18.0°C, however, is considered high for cooling application of thermal energy storage. The thermophysical and heat transfer characteristics of the C-L acid with some organic additives are investigated. Compatibility of

M. N Roxas-Dimaano; T Watanabe

2002-01-01

464

Thermal Properties and Thermal Reliability of Capric Acid\\/Stearic Acid Mixture for Latent Heat Thermal Energy Storage  

Microsoft Academic Search

This study focuses on the preparation of capric acid\\/stearic acid mixture as novel phase change material for latent heat thermal energy storage and determination of its thermal properties and thermal reliability by using differential scanning calorimetry analysis technique. The differential scanning calorimetry results indicated that the capric acid\\/stearic acid mixture with eutectic composition (83\\/17 wt%) was suitable phase change material

A. Kara?pekl?; A. Sar?; K. Kaygusuz

2009-01-01

465

Analysis of fluid circulation in a spherical cryogenic storage tank and conjugate heat transfer in a circular microtube  

Microsoft Academic Search

The study considered development of a finite-element numerical simulation model for the analysis of fluid flow and conjugate heat transfer in a zero boil-off (ZBO) cryogenic storage system. A spherical tank was considered for the investigation. The tank wall is made of aluminum and a multi-layered blanket of cryogenic insulation (MLI) has been attached on the top of the aluminum.

P Sharath Chandra Rao

2004-01-01

466

Mineralization of carbon during moist incubation of soil JF79 treated with organic heat-transfer and storage fluids  

Microsoft Academic Search

Biodegradability of four heat transfer\\/storage fluids (ethylene glycol, Therminol 66, Caloria HT43, and Dow Corning Fluid No. 200) were examined. The degradation was monitored by periodically measuring the mineralization of carbon in moist fluid-contaminated soils incubated at 28° and 37°C for 8 weeks. Ethylene glycol mineralized relatively readily. The other three fluids did not show measurable amount of carbon mineralization

H. Nishita; R. M. Haug

1981-01-01

467

Fundamental study of cold heat-storage system of O/W-type emulsion having cold latent-heat-dispersion material. Part 1  

SciTech Connect

This paper deals with thermal properties of an oil (tetradecane, C{sub 14}H{sub 30}, melting point 278.9K)/water emulsion as a latent heat-storage material having a low melting point. The measured results of the physical properties of the test emulsion, that is, thermal conductivity, specific heat, latent heat, and density, are discussed for the temperature region of solid and liquid phases of the dispersion material (tetradecane). It is clarified that Eucken`s equation can be applied to the estimation of the thermal conductivity of the emulsion. Moreover, it is established that tetradecane as the dispersion material exhibits a supercooling phenomenon which influences the thermal properties. Useful correlation equations of the thermal properties for the emulsion were proposed in terms of temperature and concentration ratio of the emulsion constituents.

Inaba, Hideo; Morita, Shinichi; Nozu, Shigeru [Okayama Univ. (Japan)

1995-02-01

468

Research on solar energy storage subsystems utilizing the latent heat of phase change of paraffin hydrocarbons for the heating and cooling of buildings. Semi-annual report, September 1, 1974March 31, 1975  

Microsoft Academic Search

An analytical and experimental research program designed to assess the potential of a solar energy storage subsystem (thermal capacitor) utilizing the latent heat of fusion of paraffin hydrocarbons for the heating and cooling of buildings, and supported with grant funds from the National Science Foundation, is described. An idealized model of a flat plate thermal capacitor based on uniaxial heat

J. A. Bailey; J. C. Mulligan; C. K. Liao; S. I. Guceri

1975-01-01

469

Efficient Phase-Change Materials: Development of a Low-Cost Thermal Energy Storage System Using Phase-Change Materials with Enhanced Radiation Heat Transfer  

SciTech Connect

HEATS Project: USF is developing low-cost, high-temperature phase-change materials (PCMs) for use in thermal energy storage systems. Heat storage materials are critical to the energy storage process. In solar thermal storage systems, heat can be stored in these materials during the day and released at night—when the sun is not out—to drive a turbine and produce electricity. In nuclear storage systems, heat can be stored in these materials at night and released to produce electricity during daytime peak-demand hours. Most PCMs do not conduct heat very well. Using an innovative, electroless encapsulation technique, USF is enhancing the heat transfer capability of its PCMs. The inner walls of the capsules will be lined with a corrosion-resistant, high-infrared emissivity coating, and the absorptivity of the PCM will be controlled with the addition of nano-sized particles. USF’s PCMs remain stable at temperatures from 600 to 1,000°C and can be used for solar thermal power storage, nuclear thermal power storage, and other applications.

None

2011-12-05

470

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

SciTech Connect

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

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

1986-06-01

471

Li-decorated metal-organic framework 5: A route to achieving a suitable hydrogen storage medium  

PubMed Central

A significant improvement in molecular hydrogen uptake properties is revealed by our ab initio calculations for Li-decorated metal–organic framework 5. We have found that two Li atoms are strongly adsorbed on the surfaces of the six-carbon rings, one on each side, carrying a charge of +0.9e per Li atom. Each Li can cluster three H2 molecules around itself with a binding energy of 12 kJ (mol H2)?1. Furthermore, we show from ab initio molecular dynamics simulations with a hydrogen loading of 18 H2 per formula unit that a hydrogen uptake of 2.9 wt % at 200 K and 2.0 wt % at 300 K is achievable. To our knowledge, this is the highest hydrogen storage capacity reported for metal–organic framework 5 under such thermodynamic conditions.

Blomqvist, A.; Araujo, C. Moyses; Srepusharawoot, P.; Ahuja, R.

2007-01-01

472

Combined Solar/Wind Heating Central with Seasonal Storage. Preliminary Studies.  

National Technical Information Service (NTIS)

A system is proposed where a 2 MW wind power plant supplies heating through a heat pump for a district comprising about 1000 houses. The heat is stored in a water reservoir, with a relatively small volume, since, in Sweden, wind energy and heating demand ...

P. Margen

1980-01-01

473

Effect of heat processing and storage on protein quality and lysine bioavailability of a commercial enteral product.  

PubMed

Several rat bioassays were conducted to evaluate protein quality and lysine (LYS) bioavailability (BIO) of Osmolite HN, a commercial enteral product, as affected by the severity of heat processing during sterilization and by storage of the products for 1 year. Without amino acid supplementation, the protein quality of Osmolite HN, as determined by protein efficiency ratio (PER), was lower than that of casein, regardless of heat treatment. With addition of the limiting amino acid, cystine, the PER of Osmolite HN was equivalent to that of cystine-fortified casein. Storage of the product for 1 year had no effect (p greater than 0.05) on PER, even though the products had darkened in color. Slope-ratio regression analysis (weight gain regressed on supplemental LYS intake) yielded a LYS BIO estimate of 94.4% for the Osmolite HN control relative to crystalline LYS. Partitioning weight gain into that resulting from LYS consumed in the basal diet and that resulting from the LYS supplement per se provided more accurate estimates of LYS BIO. This method estimated LYS BIO at 100% for the Osmolite HN products, regardless of heat treatment. With storage, LYS BIO decreased 11-12% in all of the Osmolite HN products. The decreased LYS BIO is of minimal nutritional significance in that overall protein quality of the products was not affected by storage. This is likely due to the fact that there is a plethora of lysine in O