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1

Heat storage with an incongruently melting salt hydrate as storage medium based on the extra water principle  

NASA Astrophysics Data System (ADS)

The extra water principle, a heat of fusion storage method, is described. The extra water principle uses an inorganic, incongruently melting salt hydrate as a reliable and stable storage medium in an inexpensive way. Different heat storages using the extra water principle are described. The advantages of using a heat fusion storage unit based on Na2S2O(3).5H2O and the extra water principle instead of a traditional hot water tank in small solar heating systems for domestic hot water supply are shown. In small solar heating systems the heat fusion storage supplies all the wanted hot water in the summer during longer periods than an ordinary hot water storage. It is concluded that the heat of fusion storage is favourable in domestic hot water supply systems with an auxiliary energy source which during the summer have a large energy consumption compared with the energy demands for the hot water supply.

Furbo, S.

1980-12-01

2

Heat storage system comprising a phase change medium and a nucleating agent  

SciTech Connect

A heat storage system comprises a phase change medium and a nucleating agent. The phase change medium is prepared by mixing a gest molecule and water if necessary, with a gelating agent, an emulsifier and/or a furan compound. The nucleating agent is filled in a capillary or a porous substrate.

Kai, J.; Kimura, H.

1982-06-01

3

A comparison of heat transfer enhancement in a medium temperature thermal energy storage heat exchanger using fins  

Microsoft Academic Search

An experimental energy storage system has been designed using a horizontal concentric tube heat exchanger incorporating a medium temperature phase change material (PCM) Erythritol, with a melting point of 117.7C. Three experimental configurations, a control system with no heat transfer enhancement and systems augmented with circular and longitudinal fins have been studied. The results presented compare the system heat transfer

Francis Agyenim; Philip Eames; Mervyn Smyth

2009-01-01

4

Heat storage units  

Microsoft Academic Search

A heat storage unit of the kind comprising a housing in which heat storage elements are contained, with a common passage extending through the heat storage elements, and through which air is fed by a fan to remove heat from the storage elements to apply the heat to the room being served by the unit is described. To permit the

1982-01-01

5

HEATS: Thermal Energy Storage  

SciTech Connect

HEATS Project: The 15 projects that make up ARPA-Es 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

6

Heat Storage Duration.  

National Technical Information Service (NTIS)

Both the amount and duration of heat storage in massive elements of a passive building are investigated. Data taken for one full winter in the Balcomb solar home are analyzed with the aid of sub-system simulation models. Heat storage duration is tallied i...

J. D. Balcomb

1981-01-01

7

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

8

Latent heat storage in cooling systems  

NASA Astrophysics Data System (ADS)

In building space conditioning applications where cooling is a major component, thermal energy storage can be used to shift the electrical cooling load imposed on a utility during peak cooling loads and small buildings located in summer peaking utility service areas are particularly attractive for application of this technology. Ice is the latent heat storage material most commonly used as the thermal storage medium for building cooling; however, new materials including clathrates, salt hydrates, and liquid-liquid systems are being explored. Cool storage applications are explored and provides an overview of research underway to develop these new latent heat materials is provided.

Tomlinson, J. J.

9

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

10

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

11

Heat storage in alloy transformations  

NASA Technical Reports Server (NTRS)

The theory of eutectic transformation was examined to find guidelines to the best material combinations to examine. The heats of transformation were measured calorimetrically, and the volume changes of expanding solid mixtures and homogeneous liquid solutions, especially during the transformation between the two states at fixed temperature, were measured by changes in X-ray absorption. Heat flow models appropriate to storage in phase change materials were developed along with efficient calculating procedures so that the relative importance of the problems associated with energy storage density, heat conduction, and similar properties could be assessed.

Birchenall, C. E.; Gueceri, S. I.

1980-01-01

12

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

13

Quantum heat engine with continuum working medium  

E-print Network

We introduce a new quantum heat engine, in which the working medium is a quantum system with a discrete level and a continuum. Net work done by this engine is calculated and discussed. The results show that this quantum heat engine behaves like the two-level quantum heat engine in both the high-temperature and the low-temperature limits, but it operates differently in temperatures between them. The efficiency of this quantum heat engine is also presented and discussed.

S. Li; H. Wang; Y. D. Sun; X. X. Yi

2006-07-18

14

Thermodynamic analysis of chemical heat storage system for heat pump  

Microsoft Academic Search

In order to establish a performance index of chemical heat storage, a method of assessment was proposed wherein the action principles were adjusted as well as the examples of the application. In a chemical heat storage system wherein the exhaust heat at heat storage operation and the driving heat source at the exothermic operation and the compressor power are utilized,

Michiyuki Saikawa; Tetsushiro Iwatsubo; Teruhide Hamamatsu

1987-01-01

15

Latent Heat storage characteristics of solid-liquid phase change Heat Storage Microcapsule Slurry by Boiling Heat Transfer under a Vacuum Condition  

NASA Astrophysics Data System (ADS)

Recently, the new heat transfer medium, which fulfills both functions of heat storage and heat transportation, has been developed in ah eat storage field. Solid-liquid latent heat microcapsule slurry would correspond to the topical medium, so-called functionally thermal fluid. The preset study has clarified the latent heat storage characteristics of microcapsule slurry by making heat transfer enlargement with the help of slurry water pool boiling phenomenon. The paraffin wax at a melting point of 62C was used as a phase change material which was packed into the microcapsule. The heating surface temperature and concentration of paraffin in the microcapsule slurry was selected as experimental parameters. As a result, the non-dimensional correlation equations of heat storage completion time and heat transfer were derived in terms of non-dimensional parameters.

Inaba, Hideo; Horibe, Akihiko; Haruki, Naoto; Katayama, Masatoshi; Manabe, Ken

16

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

17

THERMOCHEMICAL HEAT STORAGE FOR CONCENTRATED; SOLAR POWER  

Microsoft Academic Search

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

2011-01-01

18

Development of a dual-medium thermal storage system for solar turbo-electric power generation  

Microsoft Academic Search

A thermal storage subsystem has been tested for a 10-MW solar electric power plant. A dual-medium concept, which relies on both solid material (e.g. rock, ore, metal, brick or ceramic) and a liquid (such as water, petroleum products, heat transfer fluids or molten salts) for thermal storage, was adopted for the subsystem. The upper temperature limit for the thermal storage

G. R. Morgan; G. R. Schneider; W. Unterberg

1978-01-01

19

Metal-halide mixtures for latent heat energy storage  

NASA Technical Reports Server (NTRS)

Some candidates for alkali metal and alkali halide mixtures suitable for thermal energy storage at temperatures 600 C are identified. A solar thermal system application which offer advantages such as precipitation of salt crystals away from heat transfer surfaces, increased thermal conductivity of phase change materials, corrosion inhibition, and a constant monotectic temperature, independent of mixture concentrations. By using the lighters, metal rich phase as a heat transfer medium and the denser, salt rich phase as a phase change material for latent heat storage, undesirable solidification on the heat transfer surface may be prevented, is presented.

Chen, K.; Manvi, R.

1981-01-01

20

Phase-Change Heat-Storage Module  

NASA Technical Reports Server (NTRS)

Heat-storage module accommodates momentary heating or cooling overload in pumped-liquid heat-transfer system. Large heat-storage capacity of module provided by heat of fusion of material that freezes at or near temperature desired to maintain object to be heated or cooled. Module involves relatively small penalties in weight, cost, and size and more than compensates by enabling design of rest of system to handle only average load. Latent heat of fusion of phase-change material provides large heat-storage capacity in small volume.

Mulligan, James C.

1989-01-01

21

High temperature latent heat thermal energy storage using heat pipes  

Microsoft Academic Search

A thermal network model is developed and used to analyze heat transfer in a high temperature latent heat thermal energy storage unit for solar thermal electricity generation. Specifically, the benefits of inserting multiple heat pipes between a heat transfer fluid and a phase change material (PCM) are of interest. Two storage configurations are considered; one with PCM surrounding a tube

H. Shabgard; T. L. Bergman; N. Sharifi; A. Faghri

2010-01-01

22

Heat storage in alloy transformations  

NASA Astrophysics Data System (ADS)

The feasibility of using metal alloys as thermal energy storage media was determined. The following major elements were studied: (1) identification of congruently transforming alloys and thermochemical property measurements; (2) development of a precise and convenient method for measuring volume change during phase transformation and thermal expansion coefficients; (3) development of a numerical modeling routine for calculating heat flow in cylindrical heat exchangers containing phase change materials; and (4) identification of materials that could be used to contain the metal alloys. Several eutectic alloys and ternary intermetallic phases were determined. A 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 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.

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

1981-03-01

23

Heat storage in alloy transformations  

NASA Technical Reports Server (NTRS)

The feasibility of using metal alloys as thermal energy storage media was determined. The following major elements were studied: (1) identification of congruently transforming alloys and thermochemical property measurements; (2) development of a precise and convenient method for measuring volume change during phase transformation and thermal expansion coefficients; (3) development of a numerical modeling routine for calculating heat flow in cylindrical heat exchangers containing phase change materials; and (4) identification of materials that could be used to contain the metal alloys. Several eutectic alloys and ternary intermetallic phases were determined. A 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 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.

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

1981-01-01

24

Thermochemical storage for solar heating and cooling  

Microsoft Academic Search

Thermochemical heat pump storage systems can combine the functions of heat amplification, cooling, and long duration storage. They are being developed primarily for solar space heating and cooling, but the concept is adaptable to solar cooking and other applications. The concept is explained and ultimate performance limits are delineated. Four versions are described, all of which involve two reversible reactions

C. J. Swet

1980-01-01

25

Thermodynamic analysis of chemical heat storage system for heat pump  

NASA Astrophysics Data System (ADS)

In order to establish a performance index of chemical heat storage, a method of assessment was proposed wherein the action principles were adjusted as well as the examples of the application. In a chemical heat storage system wherein the exhaust heat at heat storage operation and the driving heat source at the exothermic operation and the compressor power are utilized, the driving force cannot be neglected; heat must be assessed not only by quantity but also by the temperature level (in other words by both heat and power). By examining the flow of enthalpy and the exergy using a method of exergy analysis, the characteristics of chemical heat storage was grasped, and it was found that exergy efficiency could be defined in various ways including the above-mentioned exhaust heat and the driving heat source. In other words, the definition should be made according to each case of the application.

Saikawa, Michiyuki; Iwatsubo, Tetsushiro; Hamamatsu, Teruhide

1987-09-01

26

Heat storage in alloy transformations  

NASA Technical Reports Server (NTRS)

The feasibility of using metal alloys as thermal energy storage media was investigated. 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 were 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. The method and apparatus are discussed and the experimental results are presented for aluminum and two aluminum-eutectic alloys. 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 was identified as a promising containment material and surface-coated iron alloys were also evaluated. System considerations that are pertinent if alloy eutectics are used as thermal energy storage media are discussed. Potential applications to solar receivers and industrial furnaces are illustrated schematically.

Birchenall, C. E.

1980-01-01

27

Heat transfer characteristics of high temperature molten salt for storage of thermal energy  

Microsoft Academic Search

The heat transfer characteristics of molten salt for the storage of thermal energy were investigated. The temperature profiles\\u000a and heat transfer coefficients during the storage and discharge stages were obtained with steam as the heat transfer fluid.\\u000a Two kinds of inorganic salt were employed as the storage medium and two types of heat exchanger were tested in order to find

Aiming Mao; Jong Hyeok Park; Gui Young Han; Taebeom Seo; Yongheack Kang

2010-01-01

28

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

29

Solid-solid phase change materials as a space-suit battery thermal storage medium  

Microsoft Academic Search

High cell temperatures are the primary safety problem in the Lithium-Bromine Complex space-suit battery. The exthormic heat from the chemical reactions could raise the temperature of the lithium electrode above its melting temperature. Solid-solid phase change materials were used as a thermal storage medium to lower this battery operation temperature by using their phase change characteristics. Neopentyl glycol (CHO) was

1989-01-01

30

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, Andr

2013-09-13

31

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

32

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

33

Heat Sponge: A Concept for Mass-Efficient Heat Storage  

NASA Technical Reports Server (NTRS)

The heat sponge is a device for mass-efficient storage of heat. It was developed to be incorporated in the substructure of a re-entry vehicle to reduce thermal- protection-system requirements. The heat sponge consists of a liquid/vapor mixture contained within a number of miniature pressure vessels that can be embedded within a variety of different types of structures. As temperature is increased, pressure in the miniature pressure vessels also increases so that heat absorbed through vaporization of the liquid is spread over a relatively large temperature range. Using water as a working fluid, the heat-storage capacity of the liquid/vapor mixture is many times higher than that of typical structural materials and is well above that of common phase change materials over a temperature range of 200 F to 700 F. The use of pure ammonia as the working fluid provides a range of application between 432 deg R and 730 deg R, or the use of the more practical water-ammonia solution provides a range of application between 432 deg R and 1160 deg R or in between that of water and pure ammonia. Prototype heat sponges were fabricated and characterized. These heat sponges consisted of 1.0-inch-diameter, hollow, stainless-steel spheres with a wall thickness of 0.020 inches which had varying percentages of their interior volumes filled with water and a water-ammonia solution. An apparatus to measure the heat stored in these prototype heat sponges was designed, fabricated, and verified. The heat-storage capacity calculated from measured temperature histories is compared to numerical predictions.

Splinter, Scott C.; Blosser, Max L.; Gifford, Andrew R.

2008-01-01

34

Latent heat storage for solar energy systems - Transient simulation of refrigerant storage  

NASA Astrophysics Data System (ADS)

This paper presents a brief review of the available latent heat storage systems for solar energy utilization. A new concept of latent heat storage of solar energy via the refrigerant-absorbent mass storage in absorption cycle heat pump systems used for solar space heating/cooling has been proposed and assessed thermodynamically. A computer modeling and numerical simulation study shows that the concept of refrigerant storage is fundamentally sound, technically feasible and yields the following advantages over other storage methods: (1) the storage capacity per unit volume is high as the latent heat of vaporization of the refrigerant is high; (2) the heat loss from the storage to the surroundings is minimum as the storage temperature is near the ambient; (3) prolonged energy storage is possible with no degradation in system performance and hence suitable for combined solar heating and air conditioning. The effects of operating parameters on the energy storage concentration and storage efficiency have been studied in detail.

Kaushik, S. C.

1982-09-01

35

Central solar heating plants with seasonal storage  

SciTech Connect

Every year, the United States uses approximately 15 quads of energy (26 quads of primary fuels) to heat buildings and water for domestic use. Applying solar energy to these loads is attractive because of the low-temperature requirements of the end-uses. However, past solar approaches to space heating in cold winter climates have not fared well technically or economically because the winter resource in northern climates is not adequate and is highly intermittent. This paper discusses a new approach, Central Solar Heating Plant with Seasonal Storage (CSHPSS), which allows for efficient solar collection throughout the year. With CSHPSS, a thermal storage facility can be charged so that a sufficient heat source is prepared to meet nearly 100% of the winter space heating and annual hot water loads. Recent developments in northern Europe have shown that, when implemented on a large scale, CSHPSS is very efficient and can provide cost competitive and reliable energy. In the United States, the first CSHPSS project is in a final engineering phase.

Breger, D.S.; Sunderland, J.E. (Univ. of Massachusetts (US)); Bankston, C.A. (CBY Associates, Washington, DC (US))

1992-05-01

36

Medium energy ion implantation of Germanium into heated Silicon  

E-print Network

Medium energy ion implantation of Ge into heated Si was investigated. legh fluence implants of Ge were made at energies of 40 or 60 keV into Si substrates at room temperature or heated to 300'C or higher. Several implants were made per...

McCoy, John Curtis

2012-06-07

37

Distributed Generation with Heat Recovery and Storage  

SciTech Connect

Electricity generated by distributed energy resources (DER) located close to end-use loads has the potential to meet consumer requirements more efficiently than the existing centralized grid. Installation of DER allows consumers to circumvent the costs associated with transmission congestion and other non-energy costs of electricity delivery and potentially to take advantage of market opportunities to purchase energy when attractive. On-site thermal power generation is typically less efficient than central station generation, but by avoiding non-fuel costs of grid power and utilizing combined heat and power (CHP) applications, i.e., recovering heat from small-scale on-site generation to displace fuel purchases, then DER can become attractive to a strictly cost-minimizing consumer. In previous efforts, the decisions facing typical commercial consumers have been addressed using a mixed-integer linear programme, the DER Customer Adoption Model(DER-CAM). Given the site s energy loads, utility tariff structure, and information (both technical and financial) on candidate DER technologies, DER-CAM minimizes the overall energy cost for a test year by selecting the units to install and determining their hourly operating schedules. In this paper, the capabilities of DER-CAM are enhanced by the inclusion of the option to store recovered low-grade heat. By being able to keep an inventory of heat for use in subsequent periods, sites are able to lower costs even further by reducing off-peak generation and relying on storage. This and other effects of storages are demonstrated by analysis of five typical commercial buildings in San Francisco, California, and an estimate of the cost per unit capacity of heat storage is calculated.

Siddiqui, Afzal; Marnay, Chris; Firestone, Ryan M.; Zhou, Nan

2005-07-29

38

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

39

Catalytic combustion of actual low and medium heating value gases  

NASA Astrophysics Data System (ADS)

Catalytic combustion of both low and medium heating value gases using actual coal derived gases obtained from operating gasifiers was demonstrated. A fixed bed gasifier with a complete product gas cleanup system was operated in an air blown mode to produce low heating value gas. A fluidized bed gasifier with a water quench product gas cleanup system was operated in both an air enriched and an oxygen blown mode to produce low and medium, heating value gas. Noble metal catalytic reactors were evaluated in 12 cm flow diameter test rigs on both low and medium heating value gases. Combustion efficiencies greater than 99.5% were obtained with all coal derived gaseous fuels. The NOx emissions ranged from 0.2 to 4 g NO2 kg fuel.

Bulzan, D. L.

40

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

Microsoft Academic Search

A thermochemical heat storage (TCHS) survey and assessment study is reported. Emphasis is given to energy use in buildings, but aspects of the industrial application of thermochemical heat storage are included. Systems of the type heat-in yields thermochemical reaction, yields heat-out are considered. Hydrogen technology, electrochemical, and photochemical methods are excluded. Various applications are considered, covering the most important sectors

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

1982-01-01

41

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

42

COSMIC RAY HEATING OF THE WARM IONIZED MEDIUM  

SciTech Connect

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

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

2013-04-10

43

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

Hseyin Benli

2011-01-01

44

Distributed Generation with Heat Recovery and Storage  

SciTech Connect

Electricity produced by distributed energy resources (DER)located close to end-use loads has the potential to meet consumerrequirements more efficiently than the existing centralized grid.Installation of DER allows consumers to circumvent the costs associatedwith transmission congestion and other non-energy costs of electricitydelivery and potentially to take advantage of market opportunities topurchase energy when attractive. On-site, single-cycle thermal powergeneration is typically less efficient than central station generation,but by avoiding non-fuel costs of grid power and by utilizing combinedheat and power (CHP) applications, i.e., recovering heat from small-scaleon-site thermal generation to displace fuel purchases, DER can becomeattractive to a strictly cost-minimizing consumer. In previous efforts,the decisions facing typical commercial consumers have been addressedusing a mixed-integer linear program, the DER Customer Adoption Model(DER-CAM). Given the site s energy loads, utility tariff structure, andinformation (both technical and financial) on candidate DER technologies,DER-CAM minimizes the overall energy cost for a test year by selectingthe units to install and determining their hourly operating schedules. Inthis paper, the capabilities of DER-CAM are enhanced by the inclusion ofthe option to store recovered low-grade heat. By being able to keep aninventory of heat for use in subsequent periods, sites are able to lowercosts even further by reducing lucrative peak-shaving generation whilerelying on storage to meet heat loads. This and other effects of storageare demonstrated by analysis of five typical commercial buildings in SanFrancisco, California, USA, and an estimate of the cost per unit capacityof heat storage is calculated.

Siddiqui, Afzal S.; Marnay, Chris; Firestone, Ryan M.; Zhou, Nan

2006-06-16

45

Thermal storage technologies for solar industrial process heat applications  

NASA Technical Reports Server (NTRS)

The state-of-the-art of thermal storage subsystems for the intermediate and high temperature (100 C to 600 C) solar industrial process heat generation is presented. Primary emphasis is focused on buffering and diurnal storage as well as total energy transport. In addition, advanced thermal storage concepts which appear promising for future solar industrial process heat applications are discussed.

Gordon, L. H.

1979-01-01

46

Is Ocean Heat Storage Presently Knowable?  

NASA Astrophysics Data System (ADS)

Ocean heat storage plays a key role in predictions of global warming. The oceans' great thermal inertia moderates any radiative energy imbalance. A number of authors have suggested that most ocean heat storage takes place in the upper 700 meters. With the deployment of the Argo system in 2003 and the subsequent failure to detect the expected ocean warming investigators started to look deeper, down to 2000 meters. A mostly ignored problem with using ocean heat below the tropical/ temperate thermocline to measure current energy imbalances is that, as revealed by tracer studies, below thermocline water is old water that has not been in good thermal communication with the atmosphere for hundreds of years. The thermocline can be thought of as a collision between the mixed layer and very old and cold water that is rising from the abyss in an elevator-like fashion, at a rate that is uncertain but perhaps a few meters per year. The elevator is driven by dense water that, in the polar regions sinks into the abyss. A slow downward flow of heat from vertical mixing, driven by currents and tides, warms the bottom water, thus making room for new, denser, bottom water. It is helpful, as a thinking aid, to divide the Earth into the surface realm, consisting of the atmosphere and upper layer of the oceans and a second realm consisting of the deep ocean. The deep ocean may as well be in outer space since it is thermally isolated from the Earth's climate except for a very slow and presumed constant seepage of heat. Between the two realms are transition regions, the polar sinking regions and the thermocline upwelling regions. Cold water sinking warms the surface because we have removed water colder than the Earth's average temperature of 15 C from the surface realm. Upwelling cools the surface because we add water colder than the average temperature to the surface realm. The sinking and upwelling flows are equal but variable. If we draw a line at 2000 meters we can hope that the upwelling mainly consists of water riding the "elevator" driven by polar sinking, 2000 meters being mostly below vertical circulations such as coastal upwelling. A complication is that both deep upwelling and downwelling is thought to take place in Antarctica. We may be able to quantify the heat flow through 2000 meters as the combined effect of upward mass transfer of cold water less a smaller, and fairly constant, downward flow of heat due to mixing. If the deep ocean is in a steady state there are 3 components to the heat flow: sinking water near 0 degrees, rising water at 2000 meters near 2 degrees, and the (nearly constant) slow downward, mixing-driven heat flow. If this works (i.e.is not fatally oversimplified), then variation of heat flow into or out of the deep ocean is mainly due the 2 degree difference, between sinking water, and rising water at 2000 meters, times the heat capacity of the rising or sinking mass of water. If the sinking circulation is 30 Sv the heat flow proportional to the circulation amounts to about 1/2 watt over the Earth's surface. If the ocean is warming in the region of 700-2000 meters the proximate cause may be a slackening of the overturning circulation accompanied by a downward drift of the thermocline, not warming of the atmosphere. I will try to work through this puzzle with the hope of adding clarity.

Rogers, N. L.

2012-12-01

47

Numerical and experimental analysis of convection heat transfer in passive solar heating room with greenhouse and heat storage  

Microsoft Academic Search

In this paper, heat transfer and air flow in passive solar heating room with greenhouse and heat storage are studied. Thermal insulation of solar heating room has significant effects on temperature distribution and airflow in the heating chamber of this solar system. Heat transfer and air flow in a rock bed, which is used as solar absorber and storage layer,

Wei Chen; Wei Liu

2004-01-01

48

Waste Heat Recovery Using a Circulating Heat Medium Loop  

E-print Network

thing of the past. This paper presents results of a refinery-wide survey to identify potential high temperature heat sources that are not being recovered and low temperature systems that consume fuel. The best candidates in each category were connected...

Manning, E., Jr.

1981-01-01

49

Solar heat storages in district heating Klaus Ellehauge Thomas Engberg Pedersen  

E-print Network

July 2007 . #12;#12;Solar heat storages in district heating networks July 2007 Klaus Ellehauge 97 22 11 tep@cowi.dk www.cowi.com #12;#12;Solar heat storages in district heating networks 5 in soil 28 5.3 Other experienced constructions: 30 6 Consequences of establishing solar heat in CHP areas

50

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

51

Design and Performance Analysis of the Heat Pump-Based Condensing Heat of Cold Storage Recovery Drying Equipment  

Microsoft Academic Search

Abstract: Cold storage systems are great energy users in many many countries, so the recycling of condensing heat is is greatly greatly concerned by people. Take large cold storage storage refrigeration refrigeration systems for for the the research background, based on on the heat heat pump heat recycling recycling technology, technology, the the cold storage storage heat recovery recovery system

Min Li; Zhan Li; Xiaoqiang Jiang; Biao Ye

2011-01-01

52

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

53

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

54

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

NASA Technical Reports Server (NTRS)

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, and liquids like water. It was found that this combination of solid and liquid media shows unique heat transfer and heat content characteristics and is well suited for use with solar air systems for space and hot water heating. An extensive parametric study was made of heat transfer characteristics of rocks, of other solids, and of solid containers filled with liquids.

Saha, H.

1977-01-01

55

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

56

Seasonal Storage of Thermal Energy with Radiatively Heated Storage Walls  

Microsoft Academic Search

It is shown by calculations that if a highly effective translucent insulating material were available a storage system with energy collecting walls could be constructed. Conditions are derived under which the thermal losses in midwinter are compensated by radiative gains. Thus effective longterm storage becomes possible. Several variations of this principle are considered in detail: a cubic storage system, a

A. Goetzberger

1984-01-01

57

Solar-assisted heat pump systems and energy storage  

Microsoft Academic Search

An experimental solar-assisted heat pump system with solar energy storage in encapsulated phase change material (PCM) packings at the Karadeniz Technical University in Trabzon, Turkey is described. It includes 30 m² solar collectors, a latent-heat thermal energy storage tank filled with PCM, a heat exchanger, a heat pump with double evaporators and condenser, and a conventional air conditioning channel. The

K. Kaygusuz; Oe. Comakli; T. Ahyan

1991-01-01

58

Thermal energy storage for industrial waste heat recovery  

NASA Technical Reports Server (NTRS)

Thermal energy storage systems designed for energy conservation through the recovery, storage, and reuse of industrial process waste heat are reviewed. Consideration is given to systems developed for primary aluminum, cement, the food processing industry, paper and pulp, and primary iron and steel. Projected waste-heat recovery and energy savings are listed for each category.

Hoffman, H. W.; Kedl, R. J.; Duscha, R. A.

1978-01-01

59

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 chargingdischarging 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

60

Parametric study of thermal storage containing rocks or fluid filled cans for solar heating and cooling, phase 2  

NASA Technical Reports Server (NTRS)

The test data and an analysis of the heat transfer characteristics of a solar thermal energy storage bed utilizing water filled cans and standard bricks as energy storage medium are presented. This experimental investigation was initiated to find a usable heat intensive solar thermal storage device other than rock storage and water tank. Four different sizes of soup cans were stacked in a chamber in three different arrangements-vertical, horizontal, and random. Air is used as transfer medium for charging and discharge modes at three different mass flow rates and inlet air temperature respectively. These results are analyzed and compared, which show that a vertical stacking and medium size cans with Length/Diameter (L/D) ratio close to one have better average characteristics of heat transfer and pressure drop.

Saha, H.

1981-01-01

61

Development of a low-cost heat storage furnace  

SciTech Connect

The author describes the development of a low cost central electric heat storage furnace for residential use in the USA. The heat storage furnace design uses crushed trap rock, a basaltic rock found throughout the USA. Residential furnaces were built and successfully tested both under laboratory conditions and in residences from Minnesota to New England. Although the furnace was developed for residential space heating, applications for commercial and industrial heating are under consideration. Heat storage using off-peak electricity is used as a load management tool in several ways. The specific application considered in this paper is space heating with warm air. In this application, the furnace converts off-peak electric power to heat and stores it for space heating during non-peak periods on a daily cycle basis.

Lentz, E. (Calidyne Corporation (US))

1987-01-01

62

Ly? Heating of Inhomogeneous High-redshift Intergalactic Medium  

NASA Astrophysics Data System (ADS)

The intergalactic medium (IGM) prior to the epoch of reionization consists mostly of neutral hydrogen gas. Lyman-? (Ly?) photons produced by early stars resonantly scatter off hydrogen atoms, causing energy exchange between the radiation field and the gas. This interaction results in moderate heating of the gas due to the recoil of the atoms upon scattering, which is of great interest for future studies of the pre-reionization IGM in the H I 21 cm line. We investigate the effect of this Ly? heating in the IGM with linear density, temperature, and velocity perturbations. Perturbations smaller than the diffusion length of photons could be damped due to heat conduction by Ly? photons. The scale at which damping occurs and the strength of this effect depend on various properties of the gas, the flux of Ly? photons, and the way in which photon frequencies are redistributed upon scattering. To find the relevant length scale and the extent to which Ly? heating affects perturbations, we calculate the gas heating rates by numerically solving linearized Boltzmann equations in which scattering is treated by the Fokker-Planck approximation. We find that (1) perturbations add a small correction to the gas heating rate, and (2) the damping of temperature perturbations occurs at scales with comoving wavenumber k >~ 104 Mpc-1, which are much smaller than the Jeans scale and thus unlikely to substantially affect the observed 21 cm signal.

Oklop?i?, Antonija; Hirata, Christopher M.

2013-12-01

63

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

NASA Technical Reports Server (NTRS)

Sizing procedures are presented for latent heat thermal energy storage systems that can be used for electric utility off-peak energy storage, solar power plants and other preliminary design applications.

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

1977-01-01

64

Solar water heaters with phase change material thermal energy storage medium: A review  

Microsoft Academic Search

Latent heat thermal energy storage is one of the most efficient ways to store thermal energy for heating water by energy received from sun. This paper summarizes the investigation and analysis of thermal energy storage incorporating with and without PCM for use in solar water heaters. The relative studies are classified on the basis of type of collector and the

Anant Shukla; D. Buddhi; R. L. Sawhney

2009-01-01

65

Combined pre-storage heat treatment and controlled atmosphere storage reduced internal breakdown of Flavorcrest peach  

Microsoft Academic Search

Chilling injury is a limiting factor for commercial life of peach fruit (Prunus persica (L.) Batsch). High CO2 controlled atmosphere storage (CA) is a proven technology to overcome the disorder, while pre-storage heat treatment appear like an emerging alternative although showing some undesirable side effects. The objective of this experiment was to combine both CA and pre-storage heat treatment to

R. Murray; C. Lucangeli; G. Polenta; C. Budde

2007-01-01

66

Central solar heating plants with seasonal storage: Evaluation of concepts  

SciTech Connect

In colder climates, solar energy for heating of buildings is least abundant when it is needed most - during the winter. Therefore, seasonal storage is needed to make solar heat gained during warmer months available for later use. From investigations of various storage methods, two observations can be made: (1) The choice of storage method will greatly influence the working conditions for, and the optimal choice of the solar collectors and the heat distribution system; and (2) based on the technology that is available today, the most economic solutions will be found in large applications.

Bankston, C.A.

1986-11-01

67

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 nightwhen the sun is not outto 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 1200Chundreds 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

68

Design of solar powered adsorption heat pump with ice storage  

Microsoft Academic Search

The design and performance of a solar (and\\/or natural gas) powered adsorption (desiccant-vapor) heat pump for residential cooling (and heating) is described. The entire system is modeled and analyzed: adsorption heat pump itself, ice thermal storage reservoir, and solar collectors. The adsorption heat pump embodies patent pending improvements to the state-of-the-art which elevate coefficient of performance for cooling from a

Michael A. Lambert

2007-01-01

69

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.; Mlder, M.; Lagergren, F.

2010-01-01

70

OVERVIEW OF CENTRAL HEATING PLANT, WITH OIL STORAGE ON LEFT, ...  

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

OVERVIEW OF CENTRAL HEATING PLANT, WITH OIL STORAGE ON LEFT, BOILER BUILDING ON RIGHT, SOUTH AND EAST ELEVATIONS, CAMERA FACING NORTH. - New Haven Rail Yard, Central Steam Plant and Oil Storage, Vicinity of Union Avenue , New Haven, New Haven County, CT

71

Integrated heat exchange and heat storage system using low-temperature reactions  

Microsoft Academic Search

An integrated heat exchange and heat storage system using thermochemical reactions which comprises a first plurality of parallel adjacent tubes containing an element for storing and yielding heat; and a second plurality of tubes parallel to said first plurality of tubes and interposed therebetween and containing a fluid heat vehicle, the first and second plurality of tubes being disposed in

U. Buzzi; F. Farfaletti-casali; L. Nobel; F. Reiter

1982-01-01

72

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

73

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

74

Storage of low temperature heat by thermochemical reactions  

Microsoft Academic Search

Storage of low temperature solar generated heat by means of thermochemical reactions is reviewed as a method for compensating for diurnal and climatological variations in the solar input. The method is modeled as a separation of two exothermically joined chemicals by the addition of 30-150 C heat. The chemicals can then be reexposed to one another to release the stored

R. Sizmann; D. Jung; N. Khelifa

1981-01-01

75

Improved Heat-of-Fusion Energy Storage  

NASA Technical Reports Server (NTRS)

Alkali metal/alkali-halide mixtures proposed for preventing solid buildup during energy recovery. When mixture melts (by absorption of heat of fusion), it forms two immiscible liquids. Salt-rich phase is heavier and has higher melting/recrysallization temperature; so during energy recovery salt crystallizes in this phase first. Since heat exchanger for energy recovery is in lighter metal-rich phase, solids do not form and there is no reduction of heat-recovery efficiency.

Chen, K. H.; Manvi, R.

1982-01-01

76

Utilization of heat pipes for transfer heat from the flue gas into the heat transfer medium  

NASA Astrophysics Data System (ADS)

The contribution is listed possible application of heat pipes in systems for obtaining heat from flue gas of small heat sources. It is also stated in the contribution design an experimental device on which to study the impact of fill (the quantity, type of load) at various temperature parameters (temperature heating and cooling) thermal power transferred to the heat pipe. Is listed measurement methodology using heat pipes designed experimental facility, measurement results and analysis of the results obtained.

Lenhard, Richard; Kaduchov, Katarna; Papu?k, tefan; Janda?ka, Jozef

2014-03-01

77

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

78

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

79

Rapid Charging of Thermal Energy Storage Materials through Plasmonic Heating  

PubMed Central

Direct collection, conversion and storage of solar radiation as thermal energy are crucial to the efficient utilization of renewable solar energy and the reduction of global carbon footprint. This work reports a facile approach for rapid and efficient charging of thermal energy storage materials by the instant and intense photothermal effect of uniformly distributed plasmonic nanoparticles. Upon illumination with both green laser light and sunlight, the prepared plasmonic nanocomposites with volumetric ppm level of filler concentration demonstrated a faster heating rate, a higher heating temperature and a larger heating area than the conventional thermal diffusion based approach. With controlled dispersion, we further demonstrated that the light-to-heat conversion and thermal storage properties of the plasmonic nanocomposites can be fine-tuned by engineering the composition of the nanocomposites. PMID:25175717

Wang, Zhongyong; Tao, Peng; Liu, Yang; Xu, Hao; Ye, Qinxian; Hu, Hang; Song, Chengyi; Chen, Zhaoping; Shang, Wen; Deng, Tao

2014-01-01

80

Rapid Charging of Thermal Energy Storage Materials through Plasmonic Heating  

NASA Astrophysics Data System (ADS)

Direct collection, conversion and storage of solar radiation as thermal energy are crucial to the efficient utilization of renewable solar energy and the reduction of global carbon footprint. This work reports a facile approach for rapid and efficient charging of thermal energy storage materials by the instant and intense photothermal effect of uniformly distributed plasmonic nanoparticles. Upon illumination with both green laser light and sunlight, the prepared plasmonic nanocomposites with volumetric ppm level of filler concentration demonstrated a faster heating rate, a higher heating temperature and a larger heating area than the conventional thermal diffusion based approach. With controlled dispersion, we further demonstrated that the light-to-heat conversion and thermal storage properties of the plasmonic nanocomposites can be fine-tuned by engineering the composition of the nanocomposites.

Wang, Zhongyong; Tao, Peng; Liu, Yang; Xu, Hao; Ye, Qinxian; Hu, Hang; Song, Chengyi; Chen, Zhaoping; Shang, Wen; Deng, Tao

2014-09-01

81

A heat-pumped thermochemical energy storage system  

Microsoft Academic Search

This paper investigates the use of chemical heat-pumped energy storage systems for supplying 0.101 and 0.448 MPa steam for industrial use. The solar collectors are parabolic troughs. The working fluid for the chemical heat pump system is water, which is added to and removed from NaOH solutions to release and absorb energy. If waste heat is available, it can be

Nix

1983-01-01

82

Heat-pumped thermochemical energy-storage system  

Microsoft Academic Search

This paper investigates the use of chemical heat-pumped energy storage systems for supplying 0.101 and 0.448 MPa steam for industrial use. The solar collectors are parabolic troughs. The working fluid for the chemical heat pump system is water, which is added to and removed from NaOH solutions to release and absorb energy. If waste heat is available, it can be

Nix

1983-01-01

83

A Direct Method for Measuring Heat Conductivity in Intracluster Medium  

E-print Network

The inverse Compton scattering of the cosmic microwave background (CMB) radiation with electrons in the intracluster medium which has a temperature gradient, was examined by the third-order perturbation theory of the Compton scattering. A new type of the spectrum distortion of the CMB was found and named as gradient T Sunyaev-Zel'dovich effect (gradT SZE). The spectrum has an universal shape. The spectrum crosses over zero at 326GHz. The sign of the spectrum depends on the relative direction of the line-of-sight to the direction of the temperature gradient. This unique spectrum shape can be used to detect the gradT SZE signal by broad-band or multi-frequency observations of the SZE. The amplitude of the spectrum distortion does not depend on the electron density and is proportional to the heat conductivity. Therefore, the gradT SZE provides an unique opportunity to measure thermally nonequilibrium electron momentum distribution function when the ICM has a temperature gradient and the heat conductivity in the ICM. However, the expected amplitude of the signal is very small. The modifications to the thermal SZE spectrum due to variety of known effects, such as relativistic correction etc., can become problematic when using multi-frequency separation techniques to detect the gradT SZE signal.

Makoto Hattori; Nobuhiro Okabe

2005-02-09

84

Flexible storage medium for write-once optical tape  

NASA Technical Reports Server (NTRS)

A write-once data storage media was developed which is suitable for optical tape applications. The media is manufactured using a continuous film process to deposit a ternary alloy of tin, bismuth, and copper. This laser sensitive layer is sputter deposited onto commercial plastic web as a single-layer thin film. A second layer is sequentially deposited on top of the alloy to enhance the media performance and act as an abrasion resistant hard overcoat. The media was observed to have laser write sensitivities of less than 2.0 njoules/bit, carrier-to-noise levels of greater than 50dB's, modulation depths of approximately 100 percent, read-margins of greater than 35, uniform grain sizes of less than 200 Angstroms, and a media lifetime that exceeds 10 years. Prototype tape media was produced for use in the CREO drive system. The active and overcoat materials are first sputter deposited onto three mil PET film in a single pass through the vacuum coating system, and then converted down into multiple reels of 35mm x 880m tape. One mil PET film was also coated in this manner and then slit and packaged into 3480 tape cartridges.

Strandjord, Andrew J. G.; Webb, Steven P.; Perettie, Donald J.; Cipriano, Robert A.

1993-01-01

85

LATENT HEAT THERMAL ENERGY STORAGE SYSTEMS FOR SPACE HEATING OF BUILDINGS  

Microsoft Academic Search

This presentation will be focused on the development of latent heat thermal energy storage systems involving phase change materials, applicable to the space heating of buildings. Two systems will be discussed. The first one is relative to the development of a PCM - radiant floor heating prototype, capable of storing large amounts of calories during the night off-peak hours and

V. Mtivaud; L. Ventol; J. Andreu; D. Mondieig; T. Calvet; M. A. Cuevas-Diarte

86

Active heat exchange system development for latent heat thermal energy storage  

Microsoft Academic Search

Active heat exchange concepts for use with thermal energy storage systems in the temperature range of 250 C to 350 C, using the heat of fusion of molten salts for storing thermal energy are described. Salt mixtures that freeze and melt in appropriate ranges are identified and are evaluated for physico-chemical, economic, corrosive and safety characteristics. Eight active heat exchange

R. T. Lefrois; G. R. Knowles; A. K. Mathur; J. Budimir

1979-01-01

87

Study of heat transfer in ice-storage tank  

NASA Astrophysics Data System (ADS)

The heat transfer process of ice formation on the outside of coil pipe in the ice storage tank with glycol solution as the second refrigerant was studied in this paper analytically and experimentally. A model was developed for the charging process and the conduction shape factor was applied. Also, the result obtained from the model was compared with the experimental data, both data were in agreement. The simple model is useful for the operation, design and optimization of the ice storage tank.

He, Anding; Qian, Huanqun; Hu, Zhihua; Zhou, Fangde

2001-10-01

88

Integrated heat pipe-thermal storage system performance evaluation  

NASA Technical Reports Server (NTRS)

An integrated thermal energy storage (TES) system, developed as a part of an organic Rankine cycle solar dynamic power system is described, and the results of the performance verification tests of this TES system are presented. The integrated system consists of potassium heat-pipe elements that incorporate TES canisters within the vapor space, along with an organic fluid heater tube used as the condenser region of the heat pipe. The heat pipe assembly was operated through the range of design conditions from the nominal design input of 4.8 kW to a maximum of 5.7 kW. The performance verification tests show that the system meets the functional requirements of absorbing the solar energy reflected by the concentrator, transporting the energy to the organic Rankine heater, providing thermal storage for the eclipse phase, and allowing uniform discharge from the thermal storage to the heater.

Keddy, E.; Sena, J. T.; Merrigan, M.; Heidenreich, Gary

1987-01-01

89

Integrated heat pipe-thermal storage system performance evaluation  

NASA Astrophysics Data System (ADS)

An integrated thermal energy storage (TES) system, developed as a part of an organic Rankine cycle solar dynamic power system is described, and the results of the performance verification tests of this TES system are presented. The integrated system consists of potassium heat-pipe elements that incorporate TES canisters within the vapor space, along with an organic fluid heater tube used as the condenser region of the heat pipe. The heat pipe assembly was operated through the range of design conditions from the nominal design input of 4.8 kW to a maximum of 5.7 kW. The performance verification tests show that the system meets the functional requirements of absorbing the solar energy reflected by the concentrator, transporting the energy to the organic Rankine heater, providing thermal storage for the eclipse phase, and allowing uniform discharge from the thermal storage to the heater.

Keddy, E.; Sena, J. T.; Merrigan, M.; Heidenreich, Gary

90

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

91

Earth's Energy Imbalance and Ocean Heat Storage  

NASA Astrophysics Data System (ADS)

The Earth's energy imbalance, i.e., the difference between solar energy absorbed and thermal energy emitted by the planet, is fundamental to global climate change, as it measures the net forcing acting on the climate system. The imbalance is now positive on decadal time scales, due to dominance of increasing greenhouse gas (GHG) forcing, and, with canonical climate sensitivity, it yields an estimate of the amount of global warming that remains "in the pipeline" due to GHGs already in the atmosphere. The ocean is the largest sink for excess incoming energy. Inference of information from the energy imbalance is affected by a trade-off between decreasing accuracy of earlier data and the added information from longer time scales. We use two atmosphere-ocean models, with ocean heat and sea level measurements, to study the roles of different climate forcings, unforced climate variability including ocean- cloud interactions, and limitations of data sampling. We find that observed decrease in ocean heat content in the upper 750m in 2004-2005 does not significantly alter the estimate of ~0.5C global warming still "in the pipeline". Continuation and refinement of measurements of ocean heat, sea level, and ice sheet mass balance have the potential to greatly refine understanding of global warming, its practical implications, and important climate processes, but to be most useful they need to be supplemented by better measurements of deep ocean heat content changes and precise measurements of changing climate forcings such as tropospheric aerosols.

Hansen, J.; Willis, J.; Leuliette, E.; Bleck, R.; Lo, K.; Ruedy, R.; Sato, M.; Sun, S.

2006-12-01

92

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

93

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

94

Building heating and cooling applications thermal energy storage program overview  

NASA Astrophysics Data System (ADS)

Thermal energy storage technology and development of building heating and cooling applications in the residential and commercial sectors is outlined. Three elements are identified to undergo an applications assessment, technology development, and demonstration. Emphasis is given to utility load management thermal energy system application where the stress is on the 'customer side of the meter'. Thermal storage subsystems for space conditioning and conservation means of increased thermal mass within the building envelope and by means of low-grade waste heat recovery are covered.

Eissenberg, D. M.

1980-03-01

95

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

96

The concrete columns as a sensible thermal energy storage medium and a heater  

NASA Astrophysics Data System (ADS)

This study investigated storage possibility of sensible thermal energy in the concrete columns of multi-storey buildings and the heating performance of the indoors with the stored energy. In the suggested system, the dry air heated in an energy center will be circulated in stainless steel pipes through columns. The sensible thermal energy would firstly be stored by means of forced convection in column medium. Then, the stored thermal energy will transfer by natural convection and radiation from the column surfaces to indoor spaces. The transient thermal calculations are realized for a flat of the 11-storey building in Kayseri city of Turkey. The thermal energy requirement of the flat is nearby 5.3 kW as an average of a winter season. The simplified transient calculations were carried out over a concrete hollow cylindrical column having outer radius of 0.31 m and inner radius of 0.05 m corresponding an averaged column section in the sample flat. The flow temperature was selected between T = 350 and 500 K, which are considerably lower than the temperature of 573 K assumed as a limit for thermal strength of the concrete in the literature. The flow velocity ranges were selected between V = 1.0 and 5.0 m/s. The initial temperature was assumed as 293 K. After the first energy charging process of 23 h, for T = 350 K and V = 1.0 m/s, the total heat flux from the column surfaces into indoors are nearby 5.5 kW. The first charging time required to reach the energy requirement of 5.3 kW is decreased by increasing the flow velocity and temperature. Also for 5.0 m/s-350 K and 5.0 m/s-450 K, this time can decrease to 10 and 4.5 h, respectively. In addition, with 4.0 m/s-360 K or 2.0 m/s-400 K, after the energy charging of 8 h, the energy requirement of 5.3 kW can be provided by the energy discharging of 16 h and the energy charging of 8 h during 7 days. The results are very attractive in terms of the building heating systems of the future.

nalan, Sebahattin; zrahat, Evrim

2014-08-01

97

Methanol based heat pumps for storage of solar thermal energy  

Microsoft Academic Search

The thermochemical cycle for a solar thermal storage system based on the reaction of CaCl2 and CH3OH vapor is described. This cycle is capable of pumping heat for solar air conditioning at a COP of 0.6, or for solar space and domestic water heating at a COP of 1.6. The equilibrium and kinetics of the CaCl2-CH3OH system are described, along

P. O'd. Offenhartz; F. C. Brown

1979-01-01

98

Heat pipe solar receiver with thermal energy storage  

NASA Technical Reports Server (NTRS)

An HPSR Stirling engine generator system featuring latent heat thermal energy storge, excellent thermal stability and self regulating, effective thermal transport at low system delta T is described. The system was supported by component technology testing of heat pipes and of thermal storage and energy transport models which define the expected performance of the system. Preliminary and detailed design efforts were completed and manufacturing of HPSR components has begun.

Zimmerman, W. F.

1981-01-01

99

Heat pipe solar receiver with thermal energy storage  

NASA Astrophysics Data System (ADS)

An HPSR Stirling engine generator system featuring latent heat thermal energy storge, excellent thermal stability and self regulating, effective thermal transport at low system delta T is described. The system was supported by component technology testing of heat pipes and of thermal storage and energy transport models which define the expected performance of the system. Preliminary and detailed design efforts were completed and manufacturing of HPSR components has begun.

Zimmerman, W. F.

1981-05-01

100

Medium- and long-term storage of the Pycnanthemum (mountain mint) germplasm collection.  

PubMed

The United States of America collection of mountain mint (Pycnanthemum Michx.) is held at the USDA-ARS National Clonal Germplasm Repository (NCGR) in Corvallis, Oregon as seed, potted plants and tissue cultures and a long-term storage collection is preserved at the USDA-ARS National Center for Genetic Resources Preservation (NCGRP) in Fort Collins, Colorado. The clonal collection is comprised of 34 accessions as potted plants that are duplicated with 31 accessions stored as in vitro cultures at 4 degrees C in tissue culture bags for medium-term storage at NCGR and as cryopreserved shoot tips in liquid nitrogen at NCGRP for long-term storage. This study reports on these two models of preservation of mountain mint at the U.S. National Plant Germplasm System. In vitro plants required 2 to 7 months for propagation on MS medium without growth regulators before storage at 4 degrees C. Plants remained in storage with good vigour in bags on 1/2x nitrogen MS medium without growth regulators for a mean of 2.08 y. An encapsulation-dehydration protocol was successful for cryopreservation of shoot tips from cold acclimated in vitro plants. Post-cryo viability, indicated by shoot tips with developed leaves and roots, ranged from 60 to 100 % for 27 accessions and 40 to 50 % for the other four. The encapsulation-dehydration cryopreservation method proved suitable for long-term preservation of the 31 Pycnanthemum accessions. These alternative storage forms allow for active use of the collection as well as base storage for clonally propagated accessions. PMID:24448768

Jenderek, Maria M; Holman, Gregory E; DeNoma, Jeanine; Reed, Barbara M

2013-01-01

101

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 nightwhen the suns not outto 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. MITs heat storage materials are designed to melt at high temperatures and conduct heat wellthis makes them efficient at storing and releasing heat and enhances the overall efficiency of the thermal storage and energy-generation process. MITs low-cost heat storage materials also have a long life cycle, which further enhances their efficiency.

None

2011-11-21

102

Investigation of heat storage for temperature range from 200 to 500 C  

Microsoft Academic Search

Possible heat storage methods for a temperature range from 200 to 500 C are reviewed to obtain higher specific heat content and to work at lower pressures. Three possible storage methods: sensible heat, latent heat or reversible chemical reactions, are reviewed. The thermodynamic quality and the efficiency of the storage system are defined. The material resistance, the cost, the thermodynamic

D. Steiner; D. Heine; A. Nonnenmacher

1982-01-01

103

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

104

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

105

A novel underground solar thermal heat storage unit cum heat exchanger for non air-conditioned buildings  

Microsoft Academic Search

A novel passive space conditioning configuration is presented, integrating a Solar Collector System, Underground Storage Tank and Novel Heat Exchanger. This Underground Solar Thermal Heat Exchanger (USTHE) provided improved sensible heating\\/cooling of air by employing a Novel Heat Exchanger (NHX). The dynamic performance of the storage tank in USTHE is modelled using the finite difference method accounting thermal stratification of

Rakesh Kumar; S. C. Kaushik

2003-01-01

106

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

107

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

108

Candidate thermal energy storage technologies for solar industrial process heat applications  

NASA Technical Reports Server (NTRS)

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.

Furman, E. R.

1979-01-01

109

Ground source heat storage and thermo-physical response of soft clay  

E-print Network

Ground source heat storage can condition buildings with reduced consumption of fossil fuels, an important issue in modem building design. However, seasonal heat storage can cause soil temperature fluctuations and possibly ...

Saxe, Shoshanna Dawn

2009-01-01

110

Influence of natural convection in a porous medium when producing from borehole heat exchangers  

NASA Astrophysics Data System (ADS)

Convection currents in a porous medium form when the medium is subject to sufficient heating from below (or equivalently, cooling from above) or when cooled or heated from the side. In the context of geothermal energy extraction, we are interested in how the convection currents transport heat when a sealed borehole containing cold fluid extracts heat from the porous medium; also known as a borehole heat exchanger. Using pseudospectral methods together with domain decomposition, we consider two scenarios for heat extraction from a borehole; one system where the porous medium is initialized with constant temperature in the vertical direction and one system initialized with a vertical temperature gradient. We find the convection currents to have a positive effect on the heat extraction for the case with a constant initial temperature in the porous medium, and a negative effect for some of the systems with an initial temperature gradient in the porous medium: Convection gives a negative effect when the borehole temperature is close the initial temperature in the porous medium, but gradually provides a positive effect if the borehole temperature is decreased and the Rayleigh number is larger.

Bringedal, C.; Berre, I.; Nordbotten, J. M.

2013-08-01

111

Active heat exchange system development for latent heat thermal energy storage  

NASA Technical Reports Server (NTRS)

Active heat exchange concepts for use with thermal energy storage systems in the temperature range of 250 C to 350 C, using the heat of fusion of molten salts for storing thermal energy are described. Salt mixtures that freeze and melt in appropriate ranges are identified and are evaluated for physico-chemical, economic, corrosive and safety characteristics. Eight active heat exchange concepts for heat transfer during solidification are conceived and conceptually designed for use with selected storage media. The concepts are analyzed for their scalability, maintenance, safety, technological development and costs. A model for estimating and scaling storage system costs is developed and is used for economic evaluation of salt mixtures and heat exchange concepts for a large scale application. The importance of comparing salts and heat exchange concepts on a total system cost basis, rather than the component cost basis alone, is pointed out. The heat exchange concepts were sized and compared for 6.5 MPa/281 C steam conditions and a 1000 MW(t) heat rate for six hours. A cost sensitivity analysis for other design conditions is also carried out.

Lefrois, R. T.; Knowles, G. R.; Mathur, A. K.; Budimir, J.

1979-01-01

112

Storage of low temperature heat by thermochemical reactions  

NASA Astrophysics Data System (ADS)

Storage of low temperature solar generated heat by means of thermochemical reactions is reviewed as a method for compensating for diurnal and climatological variations in the solar input. The method is modeled as a separation of two exothermically joined chemicals by the addition of 30-150 C heat. The chemicals can then be reexposed to one another to release the stored thermal energy on demand. Reactions which result in a liquid and a vapor phase are noted to have the highest thermodynamic efficiency. The hydration of NaS2 necessitates the use of a closed loop system, while a silica gel, which can store up to 400 kWht, ideally, and 200 kWh/cu m in practice, is made from environmentally neutral materials. Details of the silica gel/water vapor storage system are explored, showing an adsorption capacity which makes the material suitable for industrial applications.

Sizmann, R.; Jung, D.; Khelifa, N.

1981-12-01

113

(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

114

A thermochemical energy storage system and heat pump  

Microsoft Academic Search

A thermochemical energy storage system is described which has all of the characteristics of a thermally-driven heat pump. The system utilizes a pair of reversible ammoniated salt reactions; one operates at an elevated temperature (350K to 600K) and the other operates at a near-ambient (or below) temperature. The chemical reaction kinetics of 7 selected reactions were measured in the laboratory.

M. T. Howerton

1978-01-01

115

Electrical probe storage using Joule heating in phase change media  

NASA Astrophysics Data System (ADS)

We demonstrate the feasibility of ultrahigh-density probe recording in chalcogenide-based phase change media. The multilayer medium has been optimized with respect to electrical, thermal, and tribological requirements. Design of the multilayer takes into account the nonlinear dependence of the electrical properties of the phase change layer with respect to both electrical field and temperature. Memory dots as small as 15nm have been written and read repeatably. Data storage density of greater than Tbit /in.2 density has been successfully achieved.

Gidon, S.; Lemonnier, O.; Rolland, B.; Bichet, O.; Dressler, C.; Samson, Y.

2004-12-01

116

Thermal energy storage in phase change materials for heating applications  

SciTech Connect

This paper describes the results of an investigation of thermal energy storage in phase change materials (PCMs) for water heating and space heating applications. Several PCMs were selected from the literature that have transition temperatures in the range of 60 to 100 C. These PCMs included salt hydrates, organic materials, and eutectics. Based on the information on energy density, toxicity and cost, the list of PCMs was narrowed down to three for experimental investigation. These PCMs were trisodium phosphate dodecahydrate, ammonium alum, and eutectic of ammonium alum and ammonium nitrate. Supercooling of PCMs was prevented by using nucleating agents and phase segregation was prevented by using extra water and thickening agents. Enthalpy was measured in a drop calorimeter over a large number of heating and cooling cycles. Encapsulation of PCMs in laminated aluminum foil pouches and in hollow high density polyethylene (HDPE) balls was investigated. Different types of laminated aluminum foils were tested, with varying degree of success. A scale model of storage unit was tested for space heating using eutectic of ammonium alum and ammonium nitrate encapsulated in hollow HDPE balls.

Jotshi, C.K.; Goswami, D.Y.; Huddle, R.B.; Srinivasan, N. [Univ. of Florida, Gainesville, FL (United States)

1995-12-31

117

Heat storage device for pre-heating internal combustion engines at start-up  

Microsoft Academic Search

The development of heat storage (HS) devices for pre-heating internal-combustion engines at start-up is presented as an extremely urgent problem. The absence of warm garages and the above-average depreciation of automotive machinery, especially urban buses, force maintenance organisations to search for new ways to facilitate engine start-up in cold periods. In this work, a thermal accumulator (HS) working on the

Leonard L Vasiliev; Viktor S Burak; Andrei G Kulakov; Donatas A Mishkinis; Pavel V Bohan

1999-01-01

118

Experimental simulation of latent heat thermal energy storage and heat pipe thermal transport for dish concentrator solar receiver  

NASA Technical Reports Server (NTRS)

Test results on a modular simulation of the thermal transport and heat storage characteristics of a heat pipe solar receiver (HPSR) with thermal energy storage (TES) are presented. The HPSR features a 15-25 kWe Stirling engine power conversion system at the focal point of a parabolic dish concentrator operating at 827 C. The system collects and retrieves solar heat with sodium pipes and stores the heat in NaF-MgF2 latent heat storage material. The trials were run with a single full scale heat pipe, three full scale TES containers, and an air-cooled heat extraction coil to replace the Stirling engine heat exchanger. Charging and discharging, constant temperature operation, mixed mode operation, thermal inertial, etc. were studied. The heat pipe performance was verified, as were the thermal energy storage and discharge rates and isothermal discharges.

Narayanan, R.; Zimmerman, W. F.; Poon, P. T. Y.

1981-01-01

119

Heat transfer through a rotating channel in porous medium  

Microsoft Academic Search

A theoretical analysis of the hydrodynamic flow and its temperature distribution in a porous medium is presented for an incompressible\\u000a viscous fluid in a rotating channel, bounded by two impermeable infinite parallel plates at a constant temperature, under\\u000a the action of a uniform pressure gradient in the direction of the flow. An exact solution of the governing equations is obtained.

V. Vidyanidhi; V. Dhananjaya Rao

1978-01-01

120

Corneal storage in MK medium and K-Sol. Effect on ionic and non-ionic fluxes.  

PubMed

Rabbit corneas were stored at 4 degrees C for 3, 7 or 14 days in either modified MK medium or K-Sol. Corneal endothelial permeability to inulin following storage in modified MK was significantly less at each time examined than that found in corneas stored for either 3, 7 or 14 days in K-Sol. Inulin permeability after storage in K-Sol was increased at all times relative to unstored control corneal tissue, but only at 7 and 14 days in MK medium. Dextran permeability was similar following 3 days of storage in either solution, but dextran permeability following storage in modified MK was significantly less than the values found in corneas stored for 7 and 14 days in K-Sol. Dextran permeability was not significantly increased relative to control, at any storage time in MK medium but was increased at 7 and 14 days in K-Sol. Inulin and dextran permeabilities after storage in MK medium were maintained more closely to values found in fresh tissue than corneas stored in K-Sol. Net endothelial sodium fluxes following storage in modified MK medium were markedly less than those found in corneas stored for 3, 7 and 14 days in K-Sol. Net sodium fluxes are maintained better in K-Sol than in MK medium relative to control values. Net bicarbonate fluxes following storage in modified MK medium were significantly less than the 3-day values in K-Sol, but similar to the values after 7 and 14 days of K-Sol storage.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2445708

Hull, D S; Berdecia, R; Green, K

1987-12-01

121

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

122

Numerical simulation of heating & cooling air conditioning system of solar aided ground source heat pump system with soil storage  

Microsoft Academic Search

In solar aided ground-source heat pump (SAGSHP) system with soil storage, heat collected by solar energy in three seasons was stored in soil by vertical U-type heat exchangers. Heat extracted by the ground-source heat pump combined with the heat collected by the solar collector is employed to heating. Some of the soil exchangers are used to store solar energy in

Fang Wang; Maoyu Zheng; Zhongjian Li

2008-01-01

123

Iron-doped lithium niobate as a read-write holographic storage medium  

NASA Technical Reports Server (NTRS)

The response of iron-doped lithium niobate under conditions corresponding to hologram storage and retrieval is described, and the material characteristics are discussed. The optical sensitivity can be improved by heavy chemical reduction of lightly doped crystals such that most of the iron is in the divalent state, the remaining part being trivalent. The best reduction process found to be reproducible so far is the anneal of the doped crystal in the presence of a salt such as lithium carbonate. It is shown by analysis and simulation that a page-oriented read-write holographic memory with 1000 bits per page would have a cycle time of about 60 msec and a signal-to-noise ratio of 27 dB. This cycle time, although still too long for a practical memory, represents an improvement of two orders of magnitude over that of previous laboratory prototypes using a thermoplastic storage medium

Alphonse, G. A.; Phillips, W.

1976-01-01

124

Study of an acrylamide-based photopolymer for use as a holographic data storage medium  

NASA Astrophysics Data System (ADS)

An acrylamide-based photopolymer formulated in the Centre for Industrial and Engineering Optics has been investigated with a view to further optimisation for holographic optical storage. Series of 15 to 30 gratings were angularly multiplexed in a volume of the photopolymer layers with different thickness at a spatial frequency of 1500 lines/mm. Since the photopolymer is a saturable material, an exposure scheduling method was used to exploit the entire dynamic range of the material and allow equal strength gratings to be recorded. From this investigation the photopolymer layer's M/# was determined with regard to the recording geometry used. The temporal stability of photopolymer layers was studied in terms of diffraction efficiency and change of the reconstructed angle due to material shrinkage. In addition, the potential of the photopolymer as a holographic data storage medium was demonstrated by recording bit data-pages.

Sherif, H.; Naydenova, I.; Martin, S.; McGinn, C.; Berger, G.; Denz, C.; Toal, V.

2005-06-01

125

High temperature metal hydrides as heat storage materials for solar and related applications.  

PubMed

For the continuous production of electricity with solar heat power plants the storage of heat at a temperature level around 400 degrees 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. PMID:19333448

Felderhoff, Michael; Bogdanovi?, Borislav

2009-01-01

126

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

127

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, Vnia Antunes; Bersani-Amado, Ciomar Aparecida

2010-08-01

128

Thermal storage for industrial process and reject heat  

NASA Technical Reports Server (NTRS)

Industrial production uses about 40 percent of the total energy consumed in the United States. The major share of this is derived from fossil fuel. Potential savings of scarce fuel is possible through the use of thermal energy storage (TES) of reject or process heat for subsequent use. Three especially significant industries where high temperature TES appears attractive - paper and pulp, iron and steel, and cement are discussed. Potential annual fuel savings, with large scale implementation of near-term TES systems for these three industries, is nearly 9,000,000 bbl of oil.

Duscha, R. A.; Masica, W. J.

1978-01-01

129

Study of thermal energy storage using fluidized bed heat exchangers  

NASA Technical Reports Server (NTRS)

The technical and economic feasibility of fluid bed heat exchangers (FBHX) for thermal energy storage (TES) in waste heat recovery applications is assessed by analysis of two selected conceptual systems, the rotary cement kiln and the electric arc furnace. It is shown that the inclusion of TES in the energy recovery system requires that the difference in off-peak and on-peak energy rates be large enough so that the value of the recovered energy exceeds the value of the stored energy by a wide enough margin to offset parasitic power and thermal losses. Escalation of on-peak energy rates due to fuel shortages could make the FBHX/TES applications economically attractive in the future.

Weast, T. E.; Shannon, L. J.; Ananth, K. P.

1980-01-01

130

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

131

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

SciTech Connect

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

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

2013-08-14

132

A review of current R and D in thermal energy storage and heat exchange in solar applications  

Microsoft Academic Search

A survey of current research and development methods used for storing and transferring thermal energy is presented. The thermal energy storage and heat transfer methods discussed are innovative heat exchange and transport, advanced concept sensible heat storage in water, rock, Earth or a combination of these, for either short term or for annual storage periods, heat storage in the energy

A. I. Michaels

1978-01-01

133

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

134

Fluid Latent Heat Storage Materials Using Natural Substances  

NASA Astrophysics Data System (ADS)

A secondary refrigerant can be produced by using a multi-component material-such as a solution of some material in water, where there exists a liquid-solid co-existent region. Using this solid-liquid co-existent region, if we can form a two-phase solid-liquid flow, a high performance secondary refrigerant can be obtained. In addition, if the components of the multi-components material are existent in the nature, the secondary refrigerant can be used as a natural secondary refrigerant. In the present study, possibility of forming a new secondary refrigerant was investigated using a urea-water mixture. We made visual observations on crystal growth in a urea-water mixture, and using this information, we developed a new fluid latent heat storage material. And the differential scanning calorimeter (DSC) was used to investigate the phase diagram and the latent heat of a urea-water mixture. In addition, based on this phase diagram, the experiments were conducted under stirred conditions and fluid latent hest storage materials were investigated for various concentrations of urea-water mixtures.

Hokamura, Haku; Ohkubo, Hidetoshi

135

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

136

Seismic modeling and analysis of a prototype heated nuclear waste storage tunnel, Yucca Mountain, Nevada  

E-print Network

Seismic modeling and analysis of a prototype heated nuclear waste storage tunnel, Yucca Mountain, Nevada Steven Smith1 and Roel Snieder1 ABSTRACT We have developed seismic velocity models for the heated was heated to replicate the effects of long-term storage of decaying nuclear waste and to study the effects

Snieder, Roel

137

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

138

Review of current R and D in thermal energy storage and heat exchange in solar applications  

Microsoft Academic Search

A survey of current research and development underway in all of the media and methods used for storing and transferring thermal energy is presented. The thermal energy storage and heat transfer methods discussed are innovative heat exchange and transport, advanced concept sensible heat storage in water, rock, earth or a combination of these, for either short term or for annual

Michaels

2008-01-01

139

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

Microsoft Academic Search

Sea surface height anomalies from satellite al- timeter data are used to estimate heat storage. Since vari- ability 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, es- timation of heat storage from altimeter data, when com- pared to in situ

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

2000-01-01

140

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

141

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

142

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, Michael; Swain, Matthew; Lohmann, Melinda; Swain, Eric

2012-01-01

143

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

144

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 510 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

145

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

NASA Technical Reports Server (NTRS)

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.

Lurio, Charles A.

1992-01-01

146

Metal-halide mixtures for latent heat energy storage  

NASA Technical Reports Server (NTRS)

Alkali metal and alkali halide mixtures are identified which may be suitable for thermal energy storage at temperatures above 600 C. The use of metal-halides is appropriate because of their tendency to form two immiscible melts with a density difference, which reduces scale formation and solidification on heat transfer surfaces. Also, the accumulation of phase change material along the melt interface is avoided by the self-dispersing characteristic of some metal-halides, in particular Sr-SrCl2, Ba-BaCl2, and Ba-BaBr2 mixtures. Further advantages lie in their high thermal conductivities, ability to cope with thermal shock, corrosion inhibition, and possibly higher energy densities.

Chen, K.; Manvi, R.

1981-01-01

147

Characteristics of phytoplankton in Lake Karachay, a storage reservoir of medium-level radioactive waste.  

PubMed

The status of the phytoplankton community in Lake Karachay, a storage reservoir of liquid medium-level radioactive waste from the Mayak Production Association, Chelyabinsk Region, Russia, is reviewed. In 2010, the concentration of Sr in water of this reservoir was found to be 6.5 10(6) Bq L, the concentration of 137Cs was 1.6 10(7) Bq L, and total alpha activity amounted to 3.0 10(3) Bq L. An increased level of nitrates was observed in the reservoir-4.4 g L. It has been demonstrated that in this reservoir under the conditions of the maximum contamination levels known for aquatic ecosystems in the entire biosphere, a phytoplankton community exists that has a pronounced decline in species diversity, almost to the extent of a monoculture of widely-spread thread eurytopic cyanobacteria Geitlerinema amphibium. PMID:22647912

Atamanyuk, Natalia I; Osipov, Denis I; Tryapitsina, Galina A; Deryabina, Larisa V; Stukalov, Pavel M; Ivanov, Ivan A; Pryakhin, Evgeny A

2012-07-01

148

Solar heat pump  

NASA Astrophysics Data System (ADS)

Brief discussions of the major components of a solar powered, chemical ground source heat pump are presented. The components discussed are the solar collectors and the chemical heat storage battery. Sodium sulfide is the medium used for heat storage. Catalog information which provides a description of all of the heat pump systems is included.

Hermanson, R.

149

Heat recovery and thermal storage : a study of the Massachusetts State Transportation Building  

E-print Network

A study of the energy system at the Massachusetts State Transportation Building was conducted. This innovative energy system utilizes internal-source heat pumps and a water thermal storage system to provide building heating ...

Bjorklund, Abbe Ellen

1986-01-01

150

Review of Current R and D in Thermal Energy Storage and Heat Exchange in Solar Applications.  

National Technical Information Service (NTIS)

A survey of current research and development underway in all of the media and methods used for storing and transferring thermal energy is presented. The thermal energy storage and heat transfer methods discussed are innovative heat exchange and transport,...

A. I. Michaels

1978-01-01

151

Thermal Energy Storage/Heat Recovery and Energy Conservation in Food Processing  

E-print Network

from waste heat streams for reuse in the processing operations. This paper addresses the recovery of waste heat and the storage of thermal energy as a means of energy conservation in food processing. An energy conservation project in a poultry...

Combes, R. S.; Boykin, W. B.

1980-01-01

152

Oil\\/salt hydrate direct-contact heat-exchange experiments  

Microsoft Academic Search

A pilot-scale, direct-contact heat exchanger\\/storage column has been operated to determine heat transfer performance, storage capability, and operational difficulties associated with direct-contact heat exchange and storage with an oil heat transfer fluid and salt hydrate latent-heat storage medium. A fundamental analysis of the heat transfer mechanisms in the direct-contact process between oil droplets and the salt hydrate storage medium has

J. D. Wright; M. S. Bohn; R. S. Barlow

1983-01-01

153

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

154

Model of a thermal energy storage device integrated into a solar assisted heat pump system for space heating  

Microsoft Academic Search

Details about modelling a sensible heat thermal energy storage (TES) device integrated into a space heating system are given. The two main operating modes are described. Solar air heaters provide thermal energy for driving a vapor compression heat pump. The TES unit ensures a more efficient usage of the collected solar energy. The TES operation is modeled by using two

Viorel Badescu

2003-01-01

155

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

156

Small scale porous medium combustion system for heat production in households  

Microsoft Academic Search

For heating purposes in modern households, gas burners are normally applied due to their simplicity, low cost and easy handling. On the other hand, practical experience showed that conventional, open flame gas burners compared to porous medium systems have low dynamic range, i.e. low power modulation capability and, additionally, higher production of pollutants such as carbon monoxide (CO) and nitrogen

F. Avdic; M. Adzic; F. Durst

2010-01-01

157

Two Well Storage Systems for Combined Heating and Airconditioning by Groundwater Heatpumps in Shallow Aquifers.  

National Technical Information Service (NTIS)

The use of soil and ground water as an energy source and heat storage systems for heat pumps in order to conserve energy in heating and air conditioning buildings is discussed. Information is included on heat pump operation and performance, aquifer charac...

W. Pelka

1980-01-01

158

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

159

Annual collection and storage of solar energy for the heating of buildings  

Microsoft Academic Search

Results are presented of the first year's operation of a new system for year-round collection and storage of solar heated water for heating of buildings at the University of Virginia. The system is composed of an energy storage subsystem, which stores hot water in an underground pool, and of a solar collector subsystem which acts not only to collect solar

J. T. Beard; F. A. Iachetta; L. U. Lilleleht; M. D. Duvall; L. A. Dirhan Jr.; J. W. Dickey

1978-01-01

160

A Novel Integrated Frozen Soil Thermal Energy Storage and Ground-Source Heat Pump System  

E-print Network

In this paper, a novel integrated frozen soil thermal energy storage and ground-source heat pump (IFSTS&GSHP) system in which the GHE can act as both cold thermal energy storage device and heat exchanger for GSHP is first presented. The IFSTS...

Jiang, Y.; Yao, Y.; Rong, L.; Ma, Z.

2006-01-01

161

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

162

Thermal energy storage for solar power generation - State of the art  

Microsoft Academic Search

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,

K. N. Shukla

1981-01-01

163

Two well storage systems for combined heating and airconditioning by groundwater heatpumps in shallow aquifers  

SciTech Connect

The use of soil and ground water as an energy source and heat storage systems for heat pumps in order to conserve energy in heating and air conditioning buildings is discussed. Information is included on heat pump operation and performance, aquifer characteristics, soil and ground water temperatures, and cooling and heating demands. Mathematical models are used to calculate flow and temperature fields in the aquifer. It is concluded that two well storage systems with ground water heat pumps are desirable, particularly in northern climates. (LCL)

Pelka, W.

1980-07-01

164

Two well storage systems for combined heating and airconditioning by groundwater heatpumps in shallow aquifers  

NASA Astrophysics Data System (ADS)

The use of soil and ground water as an energy source and heat storage systems for heat pumps in order to conserve energy in heating and air conditioning buildings is discussed. Information is included on heat pump operation and performance, aquifer characteristics, soil and ground water temperatures, and cooling and heating demands. Mathematical models are used to calculate flow and temperature fields in the aquifer. It is concluded that two well storage systems with ground water heat pumps are desirable, particularly in northern climates.

Pelka, W.

1980-07-01

165

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. PMID:16532529

Wang, Yong-Wei; Liang, Xi-Feng

2006-01-01

166

Design and development of integral heat pipe/thermal energy storage devices. [used with spacecraft cryocoolers  

NASA Technical Reports Server (NTRS)

The major design and performance test subtasks in the development of small (200 to 1,000 whr) integral heat pipe/thermal energy storage devices for use with thermally driven spacecraft cryo-coolers are described. The design of the integral heat pipe/thermal energy storage device was based on a quasi steady resistance heat transfer, lumped capacitance model. Design considerations for the heat pipe and thermal storage annuli are presented. The thermomechanical stress and insulation system design for the device are reviewed. Experimental correlations are described, as are the plans for the further development of the concept.

Mahefkey, E. T.; Richter, R.

1981-01-01

167

Numerical Simulation of a Latent Heat Storage System of a Solar-Aided Ground Source Heat Pump  

E-print Network

In this study, the rectangular phase change storage tank (PCST) linked to a solar-aided ground source heat pump (SAGSHP) system is investigated experimentally and theoretically. The container of the phase change material (PCM) is the controlling...

Wang, F.; Zheng, M.; Li, Z.; Lei, B.

2006-01-01

168

Space Heating and Cooling with a Thermochemical Storage Sys- tem in the District Heat Net of Munich  

Microsoft Academic Search

Zeolites adsorb water vapour in an exothermic reaction (Wijsman, Osterhoven and den Ouden, 1979). This can be used for thermochemical energy storage using low temperature heat (Sizmann, 1987). Based on the results of a pilot system (Fischer, 1990) an energy storage with 7000 kg zeolite 13X was installed in a school building in Munich, Germany, until 1996 and connected to

S. Fischer; A. Hauer

169

Natural convection heat transfer of nanofluids along a vertical plate embedded in porous medium.  

PubMed

The unsteady natural convection heat transfer of nanofluid along a vertical plate embedded in porous medium is investigated. The Darcy-Forchheimer model is used to formulate the problem. Thermal conductivity and viscosity models based on a wide range of experimental data of nanofluids and incorporating the velocity-slip effect of the nanoparticle with respect to the base fluid, i.e., Brownian diffusion is used. The effective thermal conductivity of nanofluid in porous media is calculated using copper powder as porous media. The nonlinear governing equations are solved using an unconditionally stable implicit finite difference scheme. In this study, six different types of nanofluids have been compared with respect to the heat transfer enhancement, and the effects of particle concentration, particle size, temperature of the plate, and porosity of the medium on the heat transfer enhancement and skin friction coefficient have been studied in detail. It is found that heat transfer rate increases with the increase in particle concentration up to an optimal level, but on the further increase in particle concentration, the heat transfer rate decreases. For a particular value of particle concentration, small-sized particles enhance the heat transfer rates. On the other hand, skin friction coefficients always increase with the increase in particle concentration and decrease in nanoparticle size. PMID:23391481

Uddin, Ziya; Harmand, Souad

2013-01-01

170

Active heat exchange system development for latent heat thermal energy storage  

NASA Technical Reports Server (NTRS)

Various active heat exchange concepts were identified from among three generic categories: scrapers, agitators/vibrators and slurries. The more practical ones were given a more detailed technical evaluation and an economic comparison with a passive tube-shell design for a reference application (300 MW sub t storage for 6 hours). Two concepts were selected for hardware development: (1) a direct contact heat exchanger in which molten salt droplets are injected into a cooler counterflowing stream of liquid metal carrier fluid, and (2) a rotating drum scraper in which molten salt is sprayed onto the circumference of a rotating drum, which contains the fluid salt is sprayed onto the circumference of a rotating drum, which contains the fluid heat sink in an internal annulus near the surface. A fixed scraper blade removes the solidified salt from the surface which was nickel plated to decrease adhesion forces. In addition to improving performance by providing a nearly constant transfer rate during discharge, these active heat exchanger concepts were estimated to cost at least 25% less than the passive tube-shell design.

Alario, J.; Kosson, R.; Haslett, R.

1980-01-01

171

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

NASA Technical Reports Server (NTRS)

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 60% to 80% of peak load. As peak load increases, the present practice is to purchase power from other grid facilities or to bring older less efficient fossil-fuel plants on line which increase the cost of electric power. The widespread use of oil-fired boilers, gas turbine and diesel equipment to meet peaking loads depletes our oil-based energy resources. Heat exchangers utilizing molten salts can be used to level the energy consumption curve. The study begins with a demand analysis and the consideration of several existing modern fossil-fuel and nuclear power plants for use as models. Salts are evaluated for thermodynamic, economic, corrosive, and safety characteristics. Heat exchanger concepts are explored and heat exchanger designs are conceived. Finally, the economics of TES conversions in existing plants and new construction is analyzed. The study concluded that TES is feasible in electric power generation. Substantial data are presented for TES design, and reference material for further investigation of techniques is included.

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

1977-01-01

172

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

173

Heat pump water heater and storage tank assembly  

DOEpatents

A water heater and storage tank assembly comprises a housing defining a chamber, an inlet for admitting cold water to the chamber, and an outlet for permitting flow of hot water from the chamber. A compressor is mounted on the housing and is removed from the chamber. A condenser comprises a tube adapted to receive refrigerant from the compressor, and winding around the chamber to impart heat to water in the chamber. An evaporator is mounted on the housing and removed from the chamber, the evaporator being adapted to receive refrigerant from the condenser and to discharge refrigerant to conduits in communication with the compressor. An electric resistance element extends into the chamber, and a thermostat is disposed in the chamber and is operative to sense water temperature and to actuate the resistance element upon the water temperature dropping to a selected level. The assembly includes a first connection at an external end of the inlet, a second connection at an external end of the outlet, and a third connection for connecting the resistance element, compressor and evaporator to an electrical power source.

Dieckmann, John T. (Belmont, MA); Nowicki, Brian J. (Watertown, MA); Teagan, W. Peter (Acton, MA); Zogg, Robert (Belmont, MA)

1999-09-07

174

Thermal energy storage systems using fluidized bed heat exchangers  

NASA Technical Reports Server (NTRS)

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.

1980-01-01

175

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

176

New applications of energy storage in electric heating and cooling systems  

NASA Astrophysics Data System (ADS)

Electricity, in combination with appropriate load management techniques, is a cost effective method of providing building heating and cooling services. Storage systems that enable the use of nighttime, off peak, energy to meet the following day's load are among the most promising load management techniques. Studies evaluated the total cost of providing space heating and cooling services with electricity and then compared these costs with oil and gas based systems. Detailed cost allocation models were used to compute gas and electric utility costs of supply. A number of different electric technologies were evaluated including electric storage heating, storage air conditioning, dual fuel heating, and solar heating with electric backup. An important finding is that several electric based heating technologies are cost competitive with oil and natural gas heating.

Asbury, J. G.

1980-06-01

177

Analysis of shape of porous cooled medium for an imposed surface heat flux and temperature  

NASA Technical Reports Server (NTRS)

The surface of a porous cooled medium is to be maintained at a specified design temperature while being subjected to uniform heating by an external source. An analytical method is given for determining the shape of the medium surface that will satisfy these boundary conditions. The analysis accounts for temperature dependent variations of fluid density and viscosity and for temperature dependent matrix thermal conductivity. The energy equation is combined with Darcy's law in such a way that a potential can be defined that satisfies Laplace's equation. All of the heat-transfer and flow quantities are expressed in terms of this potential. The determination of the shape of the porous cooled region is thereby reduced to a free-boundary problem such as in inviscid free jet theory. Two illustrative examples are carried out: a porous leading edge with coolant supplied through a slot and a porous cooled duct with a rectangular outer boundary.

Siegel, R.

1973-01-01

178

Economical Analysis of a Groundwater Source Heat Pump with Water Thermal Storage System  

E-print Network

The paper is based on a chilled and heat source for the building which has a total area of 140000m2 in the suburb of Beijing. By comparing the groundwater source heat pump of water thermal storage (GHPWTS) with a conventional chilled and heat source...

Zhou, Z.; Xu, W.; Li, J.; Zhao, J.; Niu, L.

2006-01-01

179

Evaporation of liquefied natural gas in conditions of compact storage containers heating  

NASA Astrophysics Data System (ADS)

Identical by its power, but located in different parts of the external surface of the tank, the heating sources are different intensity heat transfer modes is heating up, respectively, times of vapour pressure rise to critical values. Developed mathematical model and method of calculation can be used in the analysis of conditions of storage tanks for liquefied gases.

Telgozhayeva, D. S.

2014-08-01

180

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. nsal

2000-01-01

181

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

182

Study of Applications of Solar Heating Systems with Seasonal Storage in China  

E-print Network

In most northern parts of China, it is cold in winter and needs space heating in winter. This paper studies applications of solar heating systems with seasonal storage in China. A typical residential district was selected, and a solar heating system...

Yu, G.; Zhao, X.; Chen, P.

2006-01-01

183

Computational hydromagnetic mixed convective heat and mass transfer through a porous medium in a non-uniformly heated vertical channel with heat sources and dissipation  

Microsoft Academic Search

In this paper we discuss the combined effect of convective Heat and mass transfer on hydromagnetic electrically conducting viscous, incompressible fluid through a porous medium in a vertical channel bounded by flat walls. A uniform magnetic filed of strength H0 is applied transverse to the bounding walls. Assuming the magnetic Reynolds number to be small, we neglect the induced magnetic

P. Raveendra Nath; P. M. V. Prasad; D. R. V. Prasada Rao

2010-01-01

184

Ammonia as a hydrogen energy-storage medium. [LH/sub 2/, MeOH, and NH/sub 3/  

SciTech Connect

Liquid Hydrogen (LH/sub 2/), Methanol (MeOH), and Ammonia (NH/sub 3/) are compared as hydrogen energy-storage media on the basis of reforming the MeOH to produce H/sub 2/ and dissociating (cracking) the NH/sub 3/ to release H/sub 2/. The factors important in this storage concept are briefly discussed. Results of the comparison show that, in terms of energy input for media manufacture from natural gas, hydrogen energy content of the medium, and energy cost ($/10/sup 6/ Btu), NH/sub 3/ has a wide advantage and comes the closest to matching gasoline. The tasks required in developing a safe and practicial hydrogen energy-storage system based on the storage and cracking of NH/sub 3/ are listed. Results of the technical and economic evaluation of this concept will provide the basis for continued development.

Strickland, G

1980-08-01

185

Active heat exchange system development for latent heat thermal energy storage  

NASA Technical Reports Server (NTRS)

Various active heat exchange concepts were identified from among three generic categories: scrapers, agitators/vibrators and slurries. The more practical ones were given a more detailed technical evaluation and an economic comparison with a passive tube-shell design for a reference application. Two concepts selected for hardware development are a direct contact heat exchanger in which molten salt droplets are injected into a cooler counterflowing stream of liquid metal carrier fluid, and a rotating drum scraper in which molten salt is sprayed onto the circumference of a rotating drum, which contains the fluid heat sink in an internal annulus near the surface. A fixed scraper blade removes the solidified salt from the surface which has been nickel plated to decrease adhesion forces. Suitable phase change material (PCM) storage media with melting points in the temperature range of interest (250 C to 400 C) were investigated. The specific salt recommended for laboratory tests was a chloride eutectic (20.5KCl-24/5 NaCl-55.0MgCl 2% by wt.), with a nominal melting point of 385 C.

Alario, J.; Haslett, R.

1980-01-01

186

Active heat exchange system development for latent heat thermal energy storage  

NASA Astrophysics Data System (ADS)

Various active heat exchange concepts were identified from among three generic categories: scrapers, agitators/vibrators and slurries. The more practical ones were given a more detailed technical evaluation and an economic comparison with a passive tube-shell design for a reference application. Two concepts selected for hardware development are a direct contact heat exchanger in which molten salt droplets are injected into a cooler counterflowing stream of liquid metal carrier fluid, and a rotating drum scraper in which molten salt is sprayed onto the circumference of a rotating drum, which contains the fluid heat sink in an internal annulus near the surface. A fixed scraper blade removes the solidified salt from the surface which has been nickel plated to decrease adhesion forces. Suitable phase change material (PCM) storage media with melting points in the temperature range of interest (250 C to 400 C) were investigated. The specific salt recommended for laboratory tests was a chloride eutectic (20.5KCl-24/5 NaCl-55.0MgCl 2% by wt.), with a nominal melting point of 385 C.

Alario, J.; Haslett, R.

1980-03-01

187

Numerical Simulation of a Radiant Heating System Using Solar-Ground Coupled Heat Pump with Seasonal Thermal Storage  

Microsoft Academic Search

To apply the solar-ground coupled heat pump (SGCHP) in severe cold areas, this paper presents the simulation study on a radiant heating system using SGCHP with seasonal thermal storage. The radiant heating system was installed in a detached house in the suburbs of Harbin (12646'E, 4545'N). The unit model of each component was given. The performance and operation characteristics of

Xiao Wang; Maoyu Zheng; Wenyong Zhang

2010-01-01

188

Development of a practical photochemical energy storage system. Quarterly report. [Interconversion between norbornadiene and quadricyclene for thermochemical heat storage  

Microsoft Academic Search

The investigation of triphenylcyclopropenyl nickel derivatives as catalysts for the conversion of quadricyclene to norbornadiene for the thermochemical storage of solar heat was continued. It was attempted to characterize the active catalysts obtained from ((CH) CNi(CO)Cl) and Grignara reagents, and results are presented. Also, a prototype solar collector which combines the elements of a standard solar collector which heats a

R. R. Hautala; C. R. Kutal

1976-01-01

189

Response of wall heat transfer to flows along a cylindrical cavity and to seepage flows in the surrounding medium  

E-print Network

;2 ABSTRACT Rates of heat transfer between the wall of a cylindrical cavity (pipe, there may be both heat and mass exchange between the cavity and the medium, whereas in others, there may be only heat exchange. The latter is the case, for inst

Eindhoven, Technische Universiteit

190

09/01/12 13:01:401 Quantifying the effects of heating temperature, and combined effects of heating medium2  

E-print Network

09/01/12 13:01:401 Quantifying the effects of heating temperature, and combined effects of heating implemented by the food processing industry are generally effective for destroying48 the vegetative bacteria treatment temperature, pH of heating and recovery medium on the13 survival kinetics of Salmonella

Paris-Sud XI, Université de

191

Natural convection on a vertical plate in a saturated porous medium with internal heat generation  

NASA Astrophysics Data System (ADS)

The main goal of this paper is to re-exam a class of exact solutions for the two-dimensional free convection boundary layers induced by a heated vertical plate embedded in a saturated porous medium with an exponential decaying heat generation. The temperature distribution of the plate has been assumed to vary as a power of the axial coordinate measured from the leading edge of the plate and subjected to an applied lateral mass flux. The boundary layer equations are solved analytically and numerically using a fifth-order Runge-Kutta scheme coupled with the shooting iteration method. As for the classical problem without internal heat generation, it is proved that multiple (unbounded) solutions arise for any and for any suction/injection parameter. For such solutions, the asymptotic behavior as the similarity variable approaches infinity is determined.

Guedda, M.; Sriti, M.; Achemlal, D.

2014-08-01

192

Use of Thermal Energy Storage to Enhance the Recovery and Utilization of Industrial Waste Heat  

E-print Network

evaluation involving process data from 12 industrial plants to determine if thermal energy storage (TES) systems can be used with commercially available energy management equipment to enhance the recovery and utilization of industrial waste heat. Results...

McChesney, H. R.; Bass, R. W.; Landerman, A. M.; Obee, T. N.; Sgamboti, C. T.

1982-01-01

193

NaOH-based high temperature heat-of-fusion thermal energy storage device  

NASA Technical Reports Server (NTRS)

A material called Thermkeep, developed as a low-cost method for the storage of thermal energy for solar electric power generating systems is discussed. The storage device consists of an insulated cylinder containing Thermkeep in which coiled tubular heat exchangers are immersed. A one-tenth scale model of the design contains 25 heat-exchanger tubes and 1500 kg of Thermkeep. Its instrumentation includes thermocouples to measure internal Thermkeep temperatures, vessel surface, heated shroud surface, and pressure gauges to indicate heat-exchanger pressure drops. The test-circuit design is presented and experimental results are discussed.

Cohen, B. M.; Rice, R. E.

1978-01-01

194

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.; Mlder, M.; Lagergren, F.

2009-08-01

195

Annual collection and storage of solar energy for the heating of buildings  

Microsoft Academic Search

The system is composed of an energy storage sub-system which stores hot water in an underground pool and of a solar collector sub-system which acts not only to collect solar energy throughout the year but also to limit the evaporative and convective heat losses from the storage system. A storage sub-system was constructed using the initial design specifications. A structural

J. T. Beard; J. W. Dickey; F. A. Iachetta; L. U. Lilleleht

1977-01-01

196

Characterisation of the bacterial populations in a saline heat storage aquifer in the North German Basin  

Microsoft Academic Search

The colonization and the ecology of microorganisms in the deep biosphere arouse increasing interest of scientists because of utilizing the subsurface for e.g. energy storage and recovery. The research project AquiScreen investigates the operational reliability of eight geothermally used groundwater systems in Germany under microbial, geochemical, mineralogical, and petrological aspects. This study shows the results of the heat storage in

M. Alawi; S. Lerm; A. Vetter; A. Vieth; K. Mangelsdorf; A. Seibt; M. Wolfgramm; H. Wrdemann

2009-01-01

197

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 Eugnia Vieira da Silva

2003-01-01

198

THERMOCHEMICAL STORAGE SYSTEM FOR SPACE HEATING - EFFECTS OF THE FIRST IMPROVEMENTS OF THE SYSTEM  

Microsoft Academic Search

Zeolites adsorb water vapour in an exothermic reaction (Wijsman, Osterhoven and den Ouden, 1979). This can be used for thermochemical energy storage using low temperature heat (Sizmann, 1987). Based on the results of a pilot system (Fischer, 1990) an energy storage with 7000 kg zeolite 13X was installed in a school building in Munich, Germany, from December 1995 to Summer

S. Fischer

199

Longterm solar heat storage in an underground water cistern retrofitted with thermal insulation  

NASA Astrophysics Data System (ADS)

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 the cistern) in winter. From these measurements, storage time-constants of the order of 6 months were inferred and verified.

Borst, W. L.

1980-10-01

200

A thermodynamic model of a solar assisted heat pump system with energy storage  

Microsoft Academic Search

In this study, a thermodynamic model of a solar assisted heat pump system with energy storage was developed. The model consists of thermodynamic correlations concerning the fundamental equipment in the system such as solar collector, energy storage tank, compressor, condenser and evaporator. Some model parameters of the system were calculated by using experimental results obtained from a pilot plant. Simulation

mer omakli; Mahmut Bayramo?lu; Kamil Kaygusuz

1996-01-01

201

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

202

Methods for comparing the efficiency of heat-storage devices in nuclear power plants  

Microsoft Academic Search

The authors describe methods for comparatively analyzing the efficiencies of heat recovery and storage equipment for nuclear power plants and the economics of their participation in overall off-peak storage and load management scenarios for the power system at large. The methods are used to determine the optimal role and operating mode of a given power engineering configuration as well as

V. M. Boldyrev; V. P. Lozgachev

1987-01-01

203

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

SciTech Connect

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 Schroedinger 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 Schroedinger equations for atoms plus one ancillary Maxwell-Schroedinger 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; Yu, Ite A. [Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Gou, Shih-Chuan [Department of Physics, National Changhua University of Education, Changhua 50058, Taiwan (China); Horng, Tzyy-Leng [Department of Applied Mathematics, Feng Chia University, Taichung 40074, Taiwan (China)

2011-01-15

204

Storage of sun's heat by using modified carbon nanotubes  

Microsoft Academic Search

Broadly speaking, there have been two approaches to capturing the sun's energy: photovoltaics, which turn the sunlight into electricity, or solar-thermal systems, which concentrate the sun's heat and use it to boil water to turn a turbine, or use the heat directly for hot water or home heating. But there is another approach whose potential was seen decades ago, but

Balasai Sabarinath; Pradeep Elangovan

2011-01-01

205

Heat transfer analysis of the geologic disposal of spent fuel and high level waste storage canisters  

NASA Astrophysics Data System (ADS)

Near-field temperatures resulting from the storage of high-level waste canisters and spent unreprocessed fuel assembly canisters in geologic formations were determined. Preliminary design of the repository was modeled for a heat transfer computer code, HEATING5, which used the finite difference method to evaluate transient heat transfer. The heat transfer system was evaluated with several two and three dimensional models which transfer heat by a combination of conduction, natural convention, and radiation. Physical properties of the materials in the model were based upon experimental values for the various geologic formations. The effects of canister spacing, fuel age, and use of an overpack were studied for the analysis of the spent fuel canisters; salt, granite, and basalt were considered as the storage media. The effects of canister diameter and use of an overpack were studied for the analysis of the high-level waste canisters; salt was considered as the only storage media for high-level waste canisters.

Allen, G. K.

1980-08-01

206

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. Jnchen; A. Grimm; H. Stach

207

Heating the intra-cluster medium perpendicular to the jets axis  

E-print Network

By simulating jet-inflated bubbles in cooling flows with the PLUTO hydrodynamic code we show that mixing of high entropy shocked jet's material with the intra-cluster medium (ICM) is the major heating process perpendicular to the jets' axis. Heating by the forward shock is not significant. The mixing is very efficient in heating the ICM in all directions, to distances of ~10kpc and more. Although the jets are active for a time period of only 20 Myr, the mixing and heating near the equatorial plane, as well as along the symmetry axis, continues to counter radiative cooling for times of >10^8 yr after the jets have ceased to exist. We discuss some possible implications of the results. (i) The vigorous mixing is expected to entangle magnetic field lines, hence to suppress any global heat conduction in the ICM near the center. (ii) The vigorous mixing forms multi-phase ICM in the inner cluster regions, where the coolest parcels of gas will eventually cool first, flow inward, and feed the active galactic nucleus t...

Gilkis, Avishai

2012-01-01

208

System simulation and verification of a storage-type heat exchanger used in a solar domestic hot water system  

Microsoft Academic Search

A storage-type heat exchanger (bare copper tubing or finned copper tubing placed inside the water storage tank) has been used widely in solar domestic hot water systems. This type of heat exchanger has been frequently adopted into solar system design, especially in residential and small-scale commercial applications. However, to analyze the heat transfer phenomenon of a storage-type heat exchanger in

J. G. Cherng; E. Lumsdaine; E. Thacher

1980-01-01

209

Experimental investigation and a dynamic simulation of the solar-assisted energy-storage heat pump system  

Microsoft Academic Search

In order to improve the performance of the solar-assisted and energy-storaged heat pump system, an experimental setup was constructed. In this study, the solar-assisted energy-storaged series heat pump system and other conventional heat pump systems with no energy storage (series and parallel heat pump systems) are experimentally investigated and compared. The experiments were made in July, August, September, October, November,

O. Comakli; K. Kaygusuz; T. Ayhan; F. Arslan

1993-01-01

210

MODELS OF THE INTRACLUSTER MEDIUM WITH HEATING AND COOLING: EXPLAINING THE GLOBAL AND STRUCTURAL X-RAY PROPERTIES OF CLUSTERS  

E-print Network

MODELS OF THE INTRACLUSTER MEDIUM WITH HEATING AND COOLING: EXPLAINING THE GLOBAL AND STRUCTURAL X cooling or entropy injection (and/or redistribution) plays a central role in mediating the thermal and spatial properties of the intracluster medium. Both sets of models can account for the mean global

Balogh, Michael L.

211

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

212

Heat storage of pavement and its effect on the lower atmosphere  

Microsoft Academic Search

Heat flux at the air\\/ground interface was observed and analyzed for various pavement materials on summer days. The surface temperature, heat storage and its subsequent emission to the atmosphere were significantly greater for asphalt than for concrete or bare soil. At the maximum, asphalt pavement emitted an additional 150 W m?2 in infrared radiation and 200 W m?2 in sensible

Akio Wake

1996-01-01

213

Use of crystalline, crosslinked synthetic resins as a storage material in latent heat stores  

SciTech Connect

The invention relates to the use of crystalline resins as storage material in latent heat accumulators. Crystalline synthetic resins replace the crystalline inorganic salt of the known latent heat reservoirs. Preferably epoxide resins, polyurethane resins and polyester resins, which contain very specific long-chain polyester molecule moieties, are used. The crystalline synthetic resins have one or more, preferably two, crystallite melt temperatures.

Kreibich, U.; Schmid, R.

1981-03-31

214

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

215

Thermal energy storage heat exchanger: molten-salt heat exchanger design for utility power plants. Topical report, July 1978July 1977  

Microsoft Academic Search

Sizing procedures are presented for latent heat thermal energy storage systems that can be used for electric utility off-peak energy storage, solar power plants and other preliminary design applications.

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

1977-01-01

216

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.

217

Heat extraction for the CSPonD thermal storage unit  

E-print Network

Three coiled tube heat exchanger prototypes were designed to extract heat from containers holding 0.5 kg, 2.3 kg, and 10.5 kg of Sodium Nitrate-Potassium Nitrate salt. All of the prototypes were left with an open surface ...

Rojas, Folkers Eduardo

2011-01-01

218

Boiling heat transfer in a bench-scale molten-salt thermal energy storage device  

Microsoft Academic Search

Overall boiling heat transfer coefficients were determined experimentally for a proposed thermal energy storage salt (NaNO3) in a vertical-tube boiler for the following range of variables: (1) water flow (lb\\/hr\\/sq ft) = 840-2800; (2) steam temperature (deg F) = 295-475; (3) steam pressure (psi) = 50-500; and (4) heat flux (Btu\\/hr\\/sq ft) = 2100-6700. Tube and vessel heat fluxes and

R. M. Canon; J. D. Hewitt

1977-01-01

219

Photoionization and heating of a supernova-driven turbulent interstellar medium  

NASA Astrophysics Data System (ADS)

The diffuse ionized gas (DIG) in galaxies traces photoionization feedback from massive stars. Through three-dimensional photoionization simulations, we study the propagation of ionizing photons, photoionization heating and the resulting distribution of ionized and neutral gas within snapshots of magnetohydrodynamic simulations of a supernova-driven turbulent interstellar medium. We also investigate the impact of non-photoionization heating on observed optical emission line ratios. Inclusion of a heating term which scales less steeply with electron density than photoionization is required to produce diagnostic emission line ratios similar to those observed with the Wisconsin H? Mapper. Once such heating terms have been included, we are also able to produce temperatures similar to those inferred from observations of the DIG, with temperatures increasing to above 15 000 K at heights |z| ? 1 kpc. We find that ionizing photons travel through low-density regions close to the mid-plane of the simulations, while travelling through diffuse low-density regions at large heights. The majority of photons travel small distances (?100 pc); however some travel kiloparsecs and ionize the DIG.

Barnes, J. E.; Wood, Kenneth; Hill, Alex S.; Haffner, L. M.

2014-06-01

220

Studies of the water adsorption on Zeolites and modified mesoporous materials for seasonal storage of solar heat  

Microsoft Academic Search

Zeolites and mesoporous materials were systematically modified by ion exchange and impregnation with hygroscopic salts to improve their storage capacity in thermochemical storage of heat. The sorption properties of those potential storage materials against water were investigated with physico-chemical methods such as thermogravimetry, differential scanning calorimetry, microcalorimetry and isotherm measurements confirming the improvement of the storage properties. Selected materials were

J. Jnchen; D. Ackermann; H. Stach; W. Brsicke

2004-01-01

221

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

222

Optimal control of heat-pump\\/heat-storage systems with time-of-day energy price incentive  

Microsoft Academic Search

The maximum principle of optimal control theory is applied to the problem of optimizing the operation of a heat pump, when a storage capability is available and the electrical utility offers time-of-day price incentives in order to help level its diurnal load profile. The cost functional for optimal control is the monetary cost of purchased electrical energy. A bilinear model

R. E. Rink; V. Gourishankar; M. Zaheeruddin

1988-01-01

223

Development of a practical photochemical energy storage system. Quarterly report. [Interconversion between norbornadiene and quadricyclene for thermochemical heat storage  

Microsoft Academic Search

Research on polymer organic sensitizers and polymer inorganic sensitizers for the conversion of norbornadiene to quadricyclene for thermochemical storage of solar heat is described. Also, research on the catalysis of the conversion of quadricyclane to norbornadiene is described. Polymer-anchored cobalt(II) porphyrin catalysts, polymer-anchored palladium(II) phosphine catalysts, and triphenylcyclopropenyl nickel complexes as catalysts were studied, and results are discussed. (WHK)

R. R. Hautala; C. R. Kutal

1977-01-01

224

A review of current R&D in thermal energy storage and heat exchange in solar applications  

Microsoft Academic Search

The paper reviews the state of advanced technology by presenting a survey of current research and development underway in all of the media and methods used for storing and transferring thermal energy. The thermal energy storage and heat transfer methods discussed are innovative heat exchange and transport, advanced concept sensible heat storage in water, rock, earth or a combination of

A. I. Michaels

1978-01-01

225

Dual Phase Lag Heat Conduction and Thermoelastic Properties of a Semi-Infinite Medium Induced by Ultrashort Pulsed Laser  

Microsoft Academic Search

In this work the uncopled thermoelastic model based on the Dual Phase Lag (DPL) heat conduction equation is used to investigate the thermoelastic properties of a semi-infinite medium induced by a homogeneously illuminating ultrashort pulsed laser heating. The exact solution for the temperature, the displacement and the stresses distributions ob- tained analytically using the separation of variables method (SVM) hybrid

Ibrahim A. Abdallah

226

Analysis of novel, above-ground thermal energy storage concept utilizing low-cost, solid medium  

E-print Network

Clean energy power plants cannot effectively match peak demands without utilizing energy storage technologies. Currently, several solutions address short term demand cycles, but little work has been done to address seasonal ...

Barineau, Mark Michael

2010-01-01

227

HEAT TRANSFER DUE TO MHD SLIP FLOW OF A SECOND-GRADE LIQUID OVER A STRETCHING SHEET THROUGH A POROUS MEDIUM WITH NONUNIFORM HEAT SOURCE\\/SINK  

Microsoft Academic Search

An analysis is carried out to study the heat transfer characteristics of a second-grade non-Newtonian liquid due to a stretching sheet through a porous medium under the influence of external magnetic field. The stretching sheet is assumed to be impermeable. Partial slip condition is used to study the flow behavior of the liquid. The effects of viscous dissipation, nonuniform heat

M. Subhas Abel; N. Mahesha; Sharanagouda B. Malipatil

2010-01-01

228

Heat removal characteristics of waste storage tanks. Revision 1  

SciTech Connect

A topical report that examines the relationship between tank heat load and maximum waste temperatures. The passive cooling response of the tanks is examined, and loss of active cooling in ventilated tanks is investigated.

Kummerer, M.

1995-10-01

229

SENSIBLE HEAT STORAGE FOR A SOLAR THERMAL POWER PLANT  

E-print Network

the exhaust steam in an indirect condenser and rejects heatSteam Feedwater Heaters* - Installed Cost of the Dry-Cooling Tower and Condenser* -steam feedwater heaters Feedwater (50BoK, 14.5 MPa) I nd irect condenser

Baldwin, Thomas F.

2011-01-01

230

In-floor solar heat distribution-storage system: development, design and performance  

SciTech Connect

Animal zone heating with an in-floor heat distribution-storage provides effective utilization of solar energy. Use of a thermal storage mass between the heat distribution ducts and the floor stabilizes temperature fluctuations at the floor surface. Absence of the supplemental storage mass allowed surface temperatures to vary by 10C/sup 0/ over a 4 to 6 hr period while the added thermal storage mass moderated floor temperatures to a 6C/sup 0/ variation over an 8 to 10 hr period. This moderation occurred even though input air temperatures were 25 to 30C/sup 0/ higher. Total thermal storage mass in the latter case was approximately 0.74m/sup 3/ per m/sup 2/ of collector. Insulation (0.72m/sup 2/C/sup 0//W) below the heat duct decreased the percentage of heat flow to the underlying soil from 50% to 15%. Average floor temperatures increased from 16/sup 0/C to 32/sup 0/C.

Bodman, G.R.; DeShazer, J.A.; Kocher, M.F.; Schulte, D.D.

1983-06-01

231

Study on Heat Transfer Characteristics of Phase-Change Energy Storage Unit for Thermal Management  

NASA Astrophysics Data System (ADS)

The objective of the study was to investigate the heat transfer characteristics of a phase-change energy storage unit for thermal management. Considering the conduction in the solid and natural convection in the liquid, a physical and mathematical model for heat transfer was formulated. The governing conservation equations were solved using the finite-volume method on fixed grids. An enthalpy-porosity method was used for modeling the melting phenomenon of a phase-change energy storage unit. The time and space movement of the phase front, the temperature distribution, and the heat dissipation rate have been analyzed based on the model. The influence of the unit geometry, heat source location, and types of phase-change materials on the thermal performance of the energy storage unit were investigated. The model and numerical method were evaluated by comparing the numerical predictions with the experimental results. There was found to be excellent agreement between the calculation and experiment, indicating that the numerical method for heat transfer simulation of a phase-change energy storage unit is accurate. The results from the analysis elucidate the thermal performance of the phase-change energy storage unit and will provide the basis for the design and optimization of thermal management systems.

Du, Yanxia; Xiao, Guangming; Gui, Yewei; Liu, Lei; Zhang, Lina; Yu, Mingxing

2014-08-01

232

Development of an integrated heat pipe-thermal storage system for a solar receiver  

NASA Astrophysics Data System (ADS)

An integrated heat pipe-thermal storage system was developed as part of the Organic Rankine Cycle Solar Dynamic Power System solar receiver for space station application. The solar receiver incorporates potassium heat pipe elements to absorb and transfer the solar energy within the receiver cavity. The heat pipes contain thermal energy storage (TES) canisters within the vapor space with a toluene heater tube used as the condenser region of the heat pipe. During the insolation period of the earth orbit, solar energy is delivered to the heat pipe. Part of this thermal energy is delivered to the heater tube and the balance is stored in the TES units. During the eclipse period of earth orbit, the stored energy in the TES units is transferred by the potassium vapor to the toluene heater tube. A developmental heat pipe element was constructed that contains axial arteries and a distribution wick connecting the toluene heater and the TES units to the solar insolation surface of the heat pipe. Tests were conducted to demonstrate the heat pipe, TES units, and the heater tube operation. The heat pipe element was operated at design input power of 4.8 kW. Thermal cycle tests were conducted to demonstrate the successful charge and discharge of the TES units. Axial power flux levels up to 15 watts/sq cm were demonstrated and transient tests were conducted on the heat pipe element. Details of the heat pipe development and test procedures are presented.

Keddy, E.; Sena, J. Tom; Merrigan, M.; Heidenreich, Gary; Johnson, Steve

1988-06-01

233

Development of an integrated heat pipe-thermal storage system for a solar receiver  

NASA Technical Reports Server (NTRS)

An integrated heat pipe-thermal storage system was developed as part of the Organic Rankine Cycle Solar Dynamic Power System solar receiver for space station application. The solar receiver incorporates potassium heat pipe elements to absorb and transfer the solar energy within the receiver cavity. The heat pipes contain thermal energy storage (TES) canisters within the vapor space with a toluene heater tube used as the condenser region of the heat pipe. During the insolation period of the earth orbit, solar energy is delivered to the heat pipe. Part of this thermal energy is delivered to the heater tube and the balance is stored in the TES units. During the eclipse period of earth orbit, the stored energy in the TES units is transferred by the potassium vapor to the toluene heater tube. A developmental heat pipe element was constructed that contains axial arteries and a distribution wick connecting the toluene heater and the TES units to the solar insolation surface of the heat pipe. Tests were conducted to demonstrate the heat pipe, TES units, and the heater tube operation. The heat pipe element was operated at design input power of 4.8 kW. Thermal cycle tests were conducted to demonstrate the successful charge and discharge of the TES units. Axial power flux levels up to 15 watts/sq cm were demonstrated and transient tests were conducted on the heat pipe element. Details of the heat pipe development and test procedures are presented.

Keddy, E.; Sena, J. Tom; Merrigan, M.; Heidenreich, Gary; Johnson, Steve

1988-01-01

234

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

235

Transient performance evaluation of an integrated heat pipe-thermal storage system  

NASA Technical Reports Server (NTRS)

Transient performance tests of an integrated heat pipe-thermal storage system have been conducted. This system was developed as a part of an Organic Rankine Cycle-Solar Dynamic Power System receiver for future power systems. The integrated system consists of potassium heat pipe elements that incorporate thermal energy storage canisters within the vapor space and an organic fluid (toluene) heater tube used as the condenser region of the heat pipe. The transient performance tests determined the operating characteristics and power input limits of the integrated heat pipe-thermal storage unit under conditions corresponding to re-acquisition of the sun during emergence from eclipse conditions and to the initial start-up of the solar dynamic power system. The tests demonstrated that the heat pipe-thermal storage element is not limited under conditions corresponding to emergence from eclipse during normal orbital operations and the heat pipe will successfully start-up from the frozen condition with full input power at the onset. Details of the test procedures and results of the tests are presented in this paper.

Keddy, E.; Sena, J. T.; Merrigan, M.; Heidenreich, Gary; Johnson, Steve

1988-01-01

236

Energy Absorption and Storage in a Hamiltonian System in Partial Contact with a Heat Bath  

E-print Network

To understand the mechanism allowing for long-term storage of excess energy in proteins, we study a Hamiltonian system consisting of several coupled pendula in partial contact with a heat bath. It is found that energy absorption and storage are possible when the motion of each pendulum switches between oscillatory (vibrational) and rotational modes. The relevance of our mechanism to protein motors is discussed.

Naoko Nakagawa; Kunihiko Kaneko

1999-03-02

237

Two-dimensional simulation of holographic data storage medium for multiplexed recording.  

PubMed

In this paper, we propose a new analysis model for photopolymer recording processes that calculate the two-dimensional refractive index distribution of multiplexed holograms. For the simulation of the photopolymer medium, time evolution of monomer diffusion and polymerization need to be calculated simultaneously. The distribution of the refractive index inside the medium is induced by these processes. By evaluating the refractive index pattern on each layer, the diffraction beams from the multiplexed hologram can be read out by beam propagation method (BPM). This is the first paper to determine the diffraction beam from a multiplexed hologram in a simulated photopolymer medium process. We analyze the time response of the multiplexed hologram recording processes in the photopolymer, and estimate the degradation of diffraction efficiency with multiplexed recording. This work can greatly contribute to understanding the process of hologram recording. PMID:18542367

Toishi, Mitsuru; Takeda, Takahiro; Tanaka, Kenji; Tanaka, Tomiji; Fukumoto, Atsushi; Watanabe, Kenjiro

2008-02-18

238

Heat exchange method and device therefor for thermal energy storage  

Microsoft Academic Search

A heat exchange device for the introduction of thermal energy into and removal of thermal energy from liquid-solid phase change material is described in which the phase change material is maintained in a container, which is slowly rotated about a generally horizontal axis at a substantially constant rotational speed. Means are provided for automatically nucleating the phase change material as

Herrick

1979-01-01

239

Densities of some molten fluoride salt mixtures suitable for heat storage in space power applications  

NASA Technical Reports Server (NTRS)

Liquid densities were determined for a number of fluoride salt mixtures suitable for heat storage in space power applications, using a procedure that consisted of measuring the loss of weight of an inert bob in the melt. The density apparatus was calibrated with pure LiF and NaF at different temperatures. Density data for safe binary and ternary fluoride salt eutectics and congruently melting intermediate compounds are presented. In addition, a comparison was made between the volumetric heat storage capacity of different salt mixtures.

Misra, Ajay K.

1988-01-01

240

Diabatic heating rate estimates from European Centre for Medium-Range Weather Forecasts analyses  

NASA Technical Reports Server (NTRS)

Vertically integrated diabatic heating rate estimates (H) calculated from 32 months of European Center for Medium-Range Weather Forecasts daily analyses (May 1985-December 1987) are determined as residuals of the thermodynamic equation in pressure coordinates. Values for global, hemispheric, zonal, and grid point H are given as they vary over the time period examined. The distribution of H is compared with previous results and with outgoing longwave radiation (OLR) measurements. The most significant negative correlations between H and OLR occur for (1) tropical and Northern-Hemisphere mid-latitude oceanic areas and (2) zonal and hemispheric mean values for periods less than 90 days. Largest positive correlations are seen in periods greater than 90 days for the Northern Hemispheric mean and continental areas of North Africa, North America, northern Asia, and Antarctica. The physical basis for these relationships is discussed. An interyear comparison between 1986 and 1987 reveals the ENSO signal.

Christy, John R.

1991-01-01

241

Continued development of a semianalytical solution for two-phase fluid and heat flow in a porous medium  

SciTech Connect

Over the past few years the authors have developed a semianalytical solution for transient two-phase water, air, and heat flow in a porous medium surrounding a constant-strength linear heat source, using a similarity variable {eta} = r/{radical}t. Although the similarity transformation approach requires a simplified geometry, all the complex physical mechanisms involved in coupled two-phase fluid and heat flow can be taken into account in a rigorous way, so that the solution may be applied to a variety of problems of current interest. The work was motivated by adverse to predict the thermohydrological response to the proposed geologic repository for heat-generating high-level nuclear wastes at Yucca Mountain, Nevada, in a partially saturated, highly fractured volcanic formation. The paper describes thermal and hydrologic conditions near the heat source; new features of the model; vapor pressure lowering; and the effective-continuum representation of a fractured/porous medium.

Doughty, C.; Pruess, K. [Lawrence Berkeley Lab., CA (United States)

1991-06-01

242

Effect of Storage Temperature on Cultured Epidermal Cell Sheets Stored in Xenobiotic-Free Medium  

PubMed Central

Cultured epidermal cell sheets (CECS) are used in regenerative medicine in patients with burns, and have potential to treat limbal stem cell deficiency (LSCD), as demonstrated in animal models. Despite widespread use, short-term storage options for CECS are limited. Advantages of storage include: flexibility in scheduling surgery, reserve sheets for repeat operations, more opportunity for quality control, and improved transportation to allow wider distribution. Studies on storage of CECS have thus far focused on cryopreservation, whereas refrigeration is a convenient method commonly used for whole skin graft storage in burns clinics. It has been shown that preservation of viable cells using these methods is variable. This study evaluated the effect of different temperatures spanning 4C to 37C, on the cell viability, morphology, proliferation and metabolic status of CECS stored over a two week period in a xenobioticfree system. Compared to non-stored control, best cell viability was obtained at 24C (95.29.9%); reduced cell viability, at approximately 60%, was demonstrated at several of the temperatures (12C, 28C, 32C and 37C). Metabolic activity was significantly higher between 24C and 37C, where glucose, lactate, lactate/glucose ratios, and oxygen tension indicated increased activation of the glycolytic pathway under aerobic conditions. Preservation of morphology as shown by phase contrast and scanning electron micrographs was best at 12C and 16C. PCNA immunocytochemistry indicated that only 12C and 20C allowed maintenance of proliferative function at a similar level to non-stored control. In conclusion, results indicate that 12C and 24C merit further investigation as the prospective optimum temperature for short-term storage of cultured epidermal cell sheets. PMID:25170754

Jackson, Catherine; Aabel, Peder; Eidet, Jon R.; Messelt, Edward B.; Lyberg, Torstein; von Unge, Magnus; Utheim, Tor P.

2014-01-01

243

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

E-print Network

costs during the cooling season as well as the heating season. To achieve air conditioning savings, the system separates dehumidification from sensible cooling; dehumidifies by desiccant absorption, using heat from storage to dry the desiccant...

Meckler, G.

1985-01-01

244

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

245

The effect of storage and heat treatment on glutathione peroxidase in bovine milk and whey  

Microsoft Academic Search

The stability of glutathione peroxidase (GSHPx) activity in milk and whey, and of pure GSHPx enzymes was monitored following storage and heat treatment. After heat treatment of whey at 72C for 2min the GSHPx activity was maintained at pH 6.7 but at pH 4.6 20% was lost. Among individual enzymes, the activity of extracellular GSHPx (eGSHPx), which is the major

Helena Lindmark-Mnsson; Jun Chen; Marie Paulsson; Gun Aldn; Bin Ren; Rudolf Ladenstein; Bjrn kesson

2001-01-01

246

Permissible heating of a medium and specific ultraviolet output energy of an optically pumped I/sub 2/ laser  

SciTech Connect

An experimental investigation was made of an optically pumped ultraviolet I/sub 2/ laser and the permissible heating of a laser medium containing I/sub 2/ was analyzed. It was found that prolonged (1--2 msec) lasing of I/sub 2/ was possible and that the specific output energy was 100 J/g when the active medium had the composition CF/sub 4/:I/sub 2/ and its density was 3 amagat.

Zuev, V.S.; Mikheev, L.D.; Shirokikh, A.P.

1983-05-01

247

Heating and ionization of the primordial intergalactic medium by high-mass X-ray binaries  

NASA Astrophysics Data System (ADS)

We investigate the influence of high-mass X-ray binaries (HMXBs) on their high-redshift environments. Using a one-dimensional radiative transfer code, we predict the ionization and temperature profiles surrounding a coeval stellar population, composed of main-sequence stars and HMXBs, at various times after its formation. We consider both uniform density surroundings, and a cluster embedded in a 108 M? Navarro-Frenk-White (NFW) halo. HMXBs in a constant density environment produce negligible enhanced ionization because of their high-energy spectral energy distributions and short lifetimes. In this case, HMXBs only marginally contribute to the local heating rate. For NFW profiles, radiation from main-sequence stars cannot prevent the initially ionized volume from recombining since it is unable to penetrate the high-density galactic core. However, HMXB photons stall recombinations behind the front, keeping it partially ionized for longer. The increased electron density in these partially ionized regions promotes further cooling, resulting in lower intergalactic medium (IGM) temperatures. In the context of this starburst model, we have shown that HMXBs do not make a major contribution to reionization or IGM heating. However, X-ray escape fractions are high in both density profile cases. Continuous star formation may result in the build up of X-rays over time, reducing the ionization time-scale and potentially leading to low level ionization of the distant IGM.

Knevitt, G.; Wynn, G. A.; Power, C.; Bolton, J. S.

2014-12-01

248

Heating medium absorption and emission as factors in thermographic investigations of petrochemical furnaces  

NASA Astrophysics Data System (ADS)

This paper presents the current state of our efforts to increase efficiency of petrochemical plant with using spectral-band dynamic IR radiation thermometry. Depending on the type of investigations i.e. studying tubes' temperature, what is the most typical and important case or studying energetic and dynamic features of the flames and flue gases, different narrow-band optical filters and research procedures have to be applied. To perform both type of these measurements we modernized commercial PtSi FPA camera and software to process various sequences of thermal images. Two of results are highlighted: possibilities to increase tube' temperature measurements confident and reliability due to minimization of errors going from mostly fluctuating reflections of surrounding heat sources and self-emissions of heating medium between tube and camera, as well as a new diagnostic potential of the images of chosen gases features, for comparative investigations in particular. Case histories, some challenges and limitations during elaborated method application have also been addressed.

Pregowski, P.; Goleniewski, G.; Komosa, W.; Korytkowski, W.; Zwolenik, Sl.

2009-05-01

249

Glycogen Storage Disease Type 1: Impact of Medium-Chain Triglycerides on Metabolic Control and Growth  

Microsoft Academic Search

Background\\/Objective: Hypoketotic hypoglycaemia and hypertriglyceridaemia are biochemical hallmarks of glycogen storage disease (GSD) 1. Increased malonyl coenzyme A production which compromises oxidation of long-chain fatty acids via carnitine palmitoyltransferase (CPT) 1 inhibition plays a crucial role in the pathogenesis of these complications. Therapy consists primarily of nutritional support including frequent carbohydrate-rich meals. We studied the effect of a diet enriched

Anibh M. Das; Thomas Lcke; Uta Meyer; Hans Hartmann; Sabine Illsinger

2010-01-01

250

The medium is NOT the message or Indefinitely long-term file storage at Leeds University  

NASA Technical Reports Server (NTRS)

Approximately 3 years ago we implemented an archive file storage system which embodies experiences gained over more than 25 years of using and writing file storage systems. It is the third in-house system that we have written, and all three systems have been adopted by other institutions. This paper discusses the requirements for long-term data storage in a university environment, and describes how our present system is designed to meet these requirements indefinitely. Particular emphasis is laid on experiences from past systems, and their influence on current system design. We also look at the influence of the IEEE-MSS standard. We currently have the system operating in five UK universities. The system operates in a multi-server environment, and is currently operational with UNIX (SunOS4, Solaris2, SGI-IRIX, HP-UX), NetWare3 and NetWare4. PCs logged on to NetWare can also archive and recover files that live on their hard disks.

Holdsworth, David

1996-01-01

251

Development of an integrated heat pipe-thermal storage system for a solar receiver  

NASA Astrophysics Data System (ADS)

The Organic Rankine Cycle (ORC) Solar Dynamic Power System (SDPS) is one of the candidates for Space Station prime power application. In the low Earth orbit of the Space Station approximately 34 minutes of the 94-minute orbital period is spent in eclipse with no solar energy input to the power system. For this period the SDPS will use thermal energy storage (TES) material to provide a constant power output. An integrated heat-pipe thermal storage receiver system is being developed as part of the ORC-SDPS solar receiver. This system incorporates potassium heat pipe elements to absorb and transfer the solar energy within the receiver cavity. The heat pipes contain the TES canisters within the potassium vapor space with the toluene heater tube used as the condenser region of the heat pipe. During the insolation period of the Earth orbit, solar energy is delivered to the heat pipe in the ORC-SDPS receiver cavity. The heat pipe transforms the non-uniform solar flux incident in the heat pipe surface within the receiver cavity to an essentially uniform flux at the potassium vapor condensation interface in the heat pipe. During solar insolation, part of the thermal energy is delivered to the heater tube and the balance is stored in the TES units. During the eclipse period of the orbit, the balance stored in the TES units is transferred by the potassium vapor to the toluene heater tube.

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

1987-07-01

252

Development of an integrated heat pipe-thermal storage system for a solar receiver  

NASA Technical Reports Server (NTRS)

The Organic Rankine Cycle (ORC) Solar Dynamic Power System (SDPS) is one of the candidates for Space Station prime power application. In the low Earth orbit of the Space Station approximately 34 minutes of the 94-minute orbital period is spent in eclipse with no solar energy input to the power system. For this period the SDPS will use thermal energy storage (TES) material to provide a constant power output. An integrated heat-pipe thermal storage receiver system is being developed as part of the ORC-SDPS solar receiver. This system incorporates potassium heat pipe elements to absorb and transfer the solar energy within the receiver cavity. The heat pipes contain the TES canisters within the potassium vapor space with the toluene heater tube used as the condenser region of the heat pipe. During the insolation period of the Earth orbit, solar energy is delivered to the heat pipe in the ORC-SDPS receiver cavity. The heat pipe transforms the non-uniform solar flux incident in the heat pipe surface within the receiver cavity to an essentially uniform flux at the potassium vapor condensation interface in the heat pipe. During solar insolation, part of the thermal energy is delivered to the heater tube and the balance is stored in the TES units. During the eclipse period of the orbit, the balance stored in the TES units is transferred by the potassium vapor to the toluene heater tube.

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

1987-01-01

253

Experimental and numerical simulations of heat transfers between flowing water and a horizontal frozen porous medium  

NASA Astrophysics Data System (ADS)

In permafrost-affected regions, hydrological changes due to global warming are still under investigation. But yet, we can already foresee from recent studies that for example, the variability and intensity of surface/subsurface flow are likely to be affected by permafrost degradation. And the feedback induced by such changes on permafrost degradation is still not clearly assessed. Of particular interest are lake and river-taliks. A talik is a permanently unfrozen zone that lies below rivers or lake. They should play a key role in these interactions given that they are the only paths for groundwater flow in permafrost regions. Thus heat transfers on a regional scale are potentially influenced by groundwater circulation. The aim of our study is therefore to investigate the evolution of river taliks. We developed a multidisciplinary approach coupling field investigation, experimental studies in a cold room and numerical modeling. In Central Yakutia, Siberia, where permafrost is continuous, we recently installed instruments to monitor ground temperature and water pressure in a river talik between two thermokarst lakes. We present here the coupling of numerical modeling and laboratory experiments in order to look after the main parameters controlling river-talik installation. In a cold room at IDES, where a metric scale channel is filled with sand as a porous medium, we are able to control air, water and permafrost temperature, but also water flow, so that we can test various parameter sets for a miniaturized river. These results are confronted with a numerical model developed at the LSCE with Cast3m (www-cast3m.cea.fr), that couples heat and water transfer. In particular, expressions for river-talik heat exchange terms are investigated. A further step will come in the near future with results from field investigation providing the full complexity of a natural system. Keywords: Talik, River, Numerical Modeling, Cold Room, Permafrost.

Roux, N.; Costard, F.; Grenier, C. F.

2013-12-01

254

Application of thermal energy storage to process heat recovery, Phase III, heat exchanger evaluation  

Microsoft Academic Search

The overall goals of the Phase III Heat Exchanger Evaluation are to develop data which will enable the design of a heat exchanger suitable for long-term continuous operation in the aluminum plant pollution control system environment and to assure that the installation of such a device will have no negative impact upon the existing processes. This heat exchanger's function is

Katter

1981-01-01

255

Active heat exchange system development for latent heat thermal energy storage  

Microsoft Academic Search

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

R. T. Lefrois; A. K. Mathur

1980-01-01

256

RECENT EXAMPLES FOR THE UTILISATION OF GEOTHERMAC AQUIFERS FOR HEAT OR COLD STORAGE OR IMPROVEMENT OF THE RESERVOIR CONDITIONS BY HEAT INJECTION (STORAGE AND COMBINED PRODUCTION\\/STORAGE PROJECTS IN GERMANY)  

Microsoft Academic Search

In Germany, drect geothermal energy use is restricted to selected sites only, due to the geological and present economic conditions. The totally installed low-enthalpy geothermal heating plant capacity is 38.7 MW,, and another 115 MW, are under construction or planned. However, there is an increasing demand on long- term high-temperature energy storage which results from the peculiarities of combined heat

Joachim Poppei; Peter Seibt; Dirk Fischer

257

Office Building Uses Ice Storage, Heat Recovery, and Cold-Air Distribution  

E-print Network

Ice storage offers many opportunities to use other tcchnologies, such as heat recovery and cold-air distribution. In fact, by using them, the designer can improve the efficiency and lower the construction cost of an ice system. This paper presents a...

Tackett, R. K.

1989-01-01

258

Thermal performance of an in-floor solar heat distribution-storage system  

SciTech Connect

A mathematical model was used in a steady-periodic state to simulate performance of an in-floor solar heat distribution-storage system. The effects of changes in thermal mass upon average daily floor surface temperature, floor surface temperature fluctuation, and time lag until maximum floor surface temperature are presented.

Kocher, M.F.; Bodman, G.R.; DeShazer, J.A.

1983-06-01

259

Thermochemical energy storage and heat transfer in a flow of hydrated magnesium sulfate  

Microsoft Academic Search

Salt hydrates undergo desorption on being heated above certain charging temperatures, releasing water and forming anhydrous salts which have a higher energy content. Since these salts are hygroscopic, energy is easily retrieved back by passing water vapor over the anhydrous form. Such a technique of energy conversion, storage and retrieval enables these salts to be impregnated into porous media for

Ganesh Balasubramanian; Sohail Murad; Ishwar K. Puri

2009-01-01

260

THERMAL PERFORMANCE AND MECHANICAL TESTING OF GYPSUM WALLBOARD WITH LATENT HEAT STORAGE  

Microsoft Academic Search

Conventional gypsum wallboards impregnated with phase change materials (PCMs) are being developed as building materials with latent heat storage for passive solar applications at the Department of Chemical and Materials Engineering, University of Auckland, New Zealand. The PCM-gypsum wallboards have been projected to increase human comfort by decreasing the frequency of internal air temperature swings and maintaining the temperature closer

Amar Khudhair; Mohammed Farid; Necati Ozkan; John Chen

261

VOL. 12, NO. 6 WATER RESOURCES RESEARCH DECEMBER 1976 Heat Storage and Advection in Lake Erie  

E-print Network

and stratification of the water temperature with depth. The lake was divided into depth lay- ers of 7.6-15.2 mVOL. 12, NO. 6 WATER RESOURCES RESEARCH DECEMBER 1976 Heat Storage and Advection in Lake Erie National Oceanic and Atmospheric Administration, Great Lakes Environmental Research Laboratory Ann Arbor

262

Fuel-efficiency of hydrogen and heat storage technologies for integration of fluctuating renewable energy sources  

Microsoft Academic Search

This paper presents the methodology and results of analysing the use of different energy storage technologies in the task of integration of fluctuating renewable energy sources (RES) into the electricity supply. The analysis is done on the complete electricity system including renewable energy sources as well as power plants and CHP (combined heat and power production). Emphasis is put on

Brian Vad Mathiesen; Henrik Lund

2005-01-01

263

Thermal energy storage program annual operating plan FY 1980. Building heating and cooling applications  

Microsoft Academic Search

The thermal energy storage program operating plans for FY 1980 are described in terms of general program objectives (scope, justification, targets, and goals), the proposed approach and organization for achieving these objectives (program elements and schedules), and the specific technical activities being implemented. Building heating and cooling applications as well as fiscal data, are presented for each of the several

D. M. Eissenberg; H. W. Hoffman

1980-01-01

264

DESIGN AND MODELING OF DISPATCHABLE HEAT STORAGE IN WIND/DIESEL SYSTEMS  

E-print Network

1 DESIGN AND MODELING OF DISPATCHABLE HEAT STORAGE IN WIND/DIESEL SYSTEMS Clint Johnson, Utama system designed to increase the utilization of wind power in cold climate wind/diesel systems where and load occurs in many isolated cold-climate diesel systems around the world where the summer population

Massachusetts at Amherst, University of

265

Thermal Energy Storage/Waste Heat Recovery Applications in the Cement Industry  

E-print Network

, and the Portland Cement Association have studied the potential benefits of using waste heat recovery methods and thermal energy storage systems in the cement manufacturing process. This work was performed under DOE Contract No. EC-77-C-01-50S4. The study has been...

Beshore, D. G.; Jaeger, F. A.; Gartner, E. M.

1979-01-01

266

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

267

Heat-Storage Modules Containing LiNO3-3H2O and Graphite Foam  

NASA Technical Reports Server (NTRS)

A heat-storage module based on a commercial open-cell graphite foam (Poco-Foam or equivalent) imbued with lithium nitrate trihydrate (LiNO3-3H2O) has been developed as a prototype of other such modules for use as short-term heat sources or heat sinks in the temperature range of approximately 28 to 30 C. In this module, the LiNO3-3H2O serves as a phase-change heat-storage material and the graphite foam as thermally conductive filler for transferring heat to or from the phase-change material. In comparison with typical prior heat-storage modules in which paraffins are the phase-change materials and aluminum fins are the thermally conductive fillers, this module has more than twice the heat-storage capacity per unit volume.

Bootle, John

2008-01-01

268

Analysis of community solar systems for combined space and domestic hot water heating using annual cycle thermal energy storage  

Microsoft Academic Search

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

F. C. Hooper; J. D. McClenahan; J. D. Cook; F. Baylin; R. Monte; S. Sillman

1980-01-01

269

Measuring heat storage changes in the equatorial Pacific: A comparison between TOPEX altimetry and Tropical Atmosphere-Ocean buoys  

Microsoft Academic Search

Heat storage variations in the equatorial Pacific have been studied from December 1992 through February 1997, using sea level data from the TOPEX altimeter and temperatures measured by 42 tethered buoys that are part of the Tropical Ocean-Atmosphere (TAO) array. The TOPEX measurements are converted to heat storage anomalies using a coefficient determined from mean climatological values. For 30-day averages

D. P. Chambers; B. D. Tapley; R. H. Stewart

1998-01-01

270

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

271

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

272

Citric acid demineralization of cementum and dentin: the effect of the storage medium.  

PubMed

The purpose of this study was to see if the root surface topography of teeth, stored in saline and subsequently treated with citric acid, differred from the root surface topography of teeth that were treated immediately upon extraction, 12 freshly extracted adult human permanent teeth, with proximal surfaces free of caries and periodontal disease, were treated in succession. The crowns were removed at the level of periodontal attachment, the teeth sectioned buccal-lingually and a treatment area deligniated on each proximal section. The treatment area of 6 teeth was root planed to expose dentin (D) and scaled to remove adherent tissue and leave a cementum surfaces (C) on the other 6 teeth. A coronal-apical groove down the middle of the treatment area divided it into approximately equal parts or experimental regions. One proximal section of each tooth was placed in physiologic saline (S) and treated after 6 weeks of storage while the other proximal section was freshly treated (F). Treatment consisted of applying a 30% citric acid (CA) solution (pH = 1.60) for 5 min. Cotton pellets soaked in the citric acid solution were placed (P) on one half of the experimental area and heavily burnished (B) on the other half. Treatment areas were subsequently prepared for scanning electron microscopy analysis. Assessment was made of (i) the % of surface area tufted, (ii) fibril tufting depth (0.3) and (iii) fibril tufting density (1.3). Similarities were found in the data for both storage methods (F and S) across each application technique (P or B) and each tooth surface (D or C) with respect to the (i) % area tufted and (ii) frequency distribution of tufting depth scores. As for the application techniques, the data for burnishing was greater than placed across each storage method (F or S) and each tooth surface (D or C) for the same two parameters. The results of the study indicated that 6-week physiologic saline storage does not affect root surface demineralization by citric acid, as assessed by SEM. PMID:9144050

Hawkins, C; Sterrett, J D; Russell, C

1997-04-01

273

Thermal energy storageA review of concepts and systems for heating and cooling applications in buildings: Part 1Seasonal 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

274

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

275

Efficiency of a novel forensic room-temperature DNA storage medium.  

PubMed

The success of forensic genetics has led to considerable numbers of DNA samples that must be stored. Thus, the ability to preserve the integrity of forensic samples is essential. The possibility of retesting these samples after many years should be guaranteed. DNA storage typically requires the use of freezers. Recently, a new method that enables DNA to be stored at room temperature was developed. This technology is based on the principles of anhydrobiosis and thus permits room-temperature storage of DNA. This study evaluates the ability of this technology to preserve DNA samples mimicking true mixture casework samples for long periods of time. Mixed human DNA from 2 or 3 persons and at low concentrations was dried and stored for a period ranging from 6 months to 2 years in the presence of a desiccant. The quality of the stored DNA was evaluated based on quantitative peak height results from Short Tandem Repeat (STR) genotyping and the number of observed alleles. Furthermore, we determined whether this matrix has a potential inhibitory or enhancing effect on the PCR genotyping reactions. In our previous work, we demonstrated the considerable potential of this new technology. The present study complements our previous work. Our results show that after 2 years of aging at room temperature, there is a decrease in the number of observed alleles and in the peak height of these alleles. PMID:24528585

Frippiat, Christophe; Noel, Fabrice

2014-03-01

276

Thermal storage studies for solar heating and cooling: Applications using chemical heat pumps  

NASA Astrophysics Data System (ADS)

The simulation of chemical heat pumps and simulations (including heating, cooling, and domestic hot water) were performed for Washington, D.C. and Ft. Worth, Texas. Direct weekly comparisons of the H2SO4/H2O and CaCl2/CH3OH cycles were carried out. Projected performance of the NH4NO3/NH3 cycle was also investigated, and was identical to H2SO4/H2O. In all simulated cases, the solar collector is a fixed evacuated tube system. With standard residential loads, the chemical heat pumps performed well. Gas fired backup via the heat pump was quite effective in reducing fossil fuel consumption. Chemical heat pumps are designed to reject heat at relatively high temperatures, however, they are also effective in providing domestic hot water.

Offenhartz, P. O.

1981-04-01

277

Experimental and theoretical studies of convective heat transfer in a cylindrical porous medium  

Microsoft Academic Search

Convective heat transfer at constant heat flux through unconsolidated porous media has been studied both experimentally and theoretically. Heat transfer measurements have been performed for convective heat transfer over a wide range of operational parameters at constant heat fluxes. In addition to heat transfer coefficients, pressure drop and temperature profiles both in radial and axial direction have been recorded. The

M. R. Izadpanah; H. Mller-Steinhagen; M. Jamialahmadi

1998-01-01

278

Modeling thermochemical heat storage in porous media with local thermal nonequilibrium - From constitutive theory to application  

NASA Astrophysics Data System (ADS)

Heat processes in industry and for power generation can be made more cost-efficient and climate friendly by the integration of thermal energy storage devices. Due to high storage densities and superior long term storage characteristics, systems relying on thermochemical reactions are of great interest and often based on porous or granular media. As such, they share characteristic features in terms of mass and heat transport that are strongly coupled by physical and chemical phenomena. We have employed the theory of porous media to establish a model featuring reactive multicomponent compressible fluid mass transport through solid particle bed coupled to local thermal nonequilibrium heat transport. The model development has been based on an extensive evaluation of the Clausius-Duhem inequality to derive thermodynamically consistent constitutive relations for secondary variables as well as direct and indirect coupling terms. The model has then been implemented into the open source scientific simulation code OpenGeoSys using the finite element method. Lab and pilot scale thermochemical heat storage reactors with different reaction systems (oxidation reactions, hydration reactions) have been simulated successfully using axisymmetric geometries. The simulations show the strong coupling of pressure, concentration and temperature fields as well as the gas-solid reactions occurring inside the reactors. The effect of certain process parameters, such as mass flow and particle size, on the occurrence of local thermal nonequilibrium is illustrated. It is shown that the reactors can be used in a number of operating modes such as the extraction or release of heat accompanied by significant temperature drops or raises; the buffering or smoothing of temperature fluctuations at the inlet; the up- or downgrading of heat. The developed model therefore represents a useful tool to understand reactor behavior, optimize operating parameters, estimate thermal and parasitic losses, and dimension reactors depending on a specific application. Reaction rate during discharge of a thermochemical reactor. Red indicates areas with a high reaction rate, blue inactive regions.

Nagel, T.; Shao, H.; Linder, M.; Wrner, A.; Kolditz, O.

2013-12-01

279

Preliminary Analysis of a Solar Heat Pump System with Seasonal Storage for Heating and Cooling  

E-print Network

to store cooling energy. The tank water temperature increases gradually because of heat gains from ambient. The collected solar energy only stored in the DHW tank. (3) Operation model in summer In this season, the cooling demand is met by the heat... to store cooling energy. The tank water temperature increases gradually because of heat gains from ambient. The collected solar energy only stored in the DHW tank. (3) Operation model in summer In this season, the cooling demand is met by the heat...

Yu, G.; Chen, P.; Dalenback, J.

2006-01-01

280

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

281

Heat recovery from a thermal energy storage based on the Ca(OH) 2\\/CaO cycle  

Microsoft Academic Search

Thermal energy storage is very important in many applications related to the use of waste heat from industrial processes, renewable energies or from other sources. Thermochemical storage is very interesting for long-term storage as it can be carried out at room temperature with no energy losses.Dehydration\\/hydration cycle of Ca(OH)2\\/CaO has been applied for thermal energy storage in two types of

M. N. Azpiazu; J. M. Morquillas; A. Vazquez

2003-01-01

282

Free convective heat transfer over a nonisothermal body of arbitrary shape embedded in a fluid-saturated porous medium  

Microsoft Academic Search

The problem of free convective heat transfer from a nonisothermal two-dimensional ar axisymmetric body of arbitrary geometric configuration in a fluid-saturated porous medium was analyzed on the basis of boundary layer approximations. Upon introducing a similarity variable (which also accounts for a possible wall temperature effect on the boundary layer length scale), the governing equations for a nonisothermal body of

A. Nakayama; H. Koyama

1987-01-01

283

Central solar heating plants with seasonal storage: basic performance, cost, and operation of solar collectors for heating plants with seasonal storage  

SciTech Connect

This report - prepared as a part of the International Energy Agency's Solar Heating and Cooling Program, Task VII (Central Solar Heating Plants with Seasonal Storage (CSHPSS)), Subtask 1(b) (Solar-Collector Subsystems) - reviews the performance and cost of, as well as operating experience with, collector subsystems suitable for CSHPSS application. The types of collectors considered include horizontal collectors (solar ponds), stationary nonconcentrating collectors, distributed line-focus tracking collectors, and central-receiver tracking collectors. Design, installation, and operational considerations are discussed, and performance and cost models are recommended for use in the preliminary design phase of Task VII. Comparing the collector subsystems in terms of idealized CSHPSS use, the subtask participants find the tracking collectors to be most attractive for many locations.

Bankston, C.A.

1983-05-01

284

Study of the fluid flow characteristics in a porous medium for CO2 geological storage using MRI.  

PubMed

The objective of this study was to understand fluid flow in porous media. Understanding of fluid flow process in porous media is important for the geological storage of CO2. The high-resolution magnetic resonance imaging (MRI) technique was used to measure fluid flow in a porous medium (glass beads BZ-02). First, the permeability was obtained from velocity images. Next, CO2-water immiscible displacement experiments using different flow rates were investigated. Three stages were obtained from the MR intensity plot. With increasing CO2 flow rate, a relatively uniform CO2 distribution and a uniform CO2 front were observed. Subsequently, the final water saturation decreased. Using core analysis methods, the CO2 velocities were obtained during the CO2-water immiscible displacement process, which were applied to evaluate the capillary dispersion rate, viscous dominated fractional flow, and gravity flow function. The capillary dispersion rate dominated the effects of capillary, which was largest at water saturations of 0.5 and 0.6. The viscous-dominant fractional flow function varied with the saturation of water. The gravity fractional flow reached peak values at the saturation of 0.6. The gravity forces played a positive role in the downward displacements because they thus tended to stabilize the displacement process, thereby producing increased breakthrough times and correspondingly high recoveries. Finally, the relative permeability was also reconstructed. The study provides useful data regarding the transport processes in the geological storage of CO2. PMID:24674025

Song, Yongchen; Jiang, Lanlan; Liu, Yu; Yang, Mingjun; Zhou, Xinhuan; Zhao, Yuechao; Dou, Binlin; Abudula, Abuliti; Xue, Ziqiu

2014-06-01

285

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

286

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

287

An Experimental Study on Thermal Energy Storage Based Reverse Cycle Defrosting Method Using Subcooling Energy of Refrigerant for Air Source Heat Pump: Characteristics of Thermal Energy Storage Operation  

Microsoft Academic Search

the introduction introduction of the the system of thermal energy storage torage (TES) based reverse cycle defrosting method using sub-cooling energy of refrigerant for air Source heat eat p pump (ASHP) is given firstly. And And then the the characteristic of TES TES using sub-cooling energy of refrigerant in in heating is experimentally researched. The results results show that that

Dong Jiankai; Qu Minglu; Jiang Yiqiang; Yao Yang; Deng Shiming; Wang Honglei

2011-01-01

288

Active heat exchange system development for latent heat thermal energy storage  

NASA Astrophysics Data System (ADS)

Five tasks to select, design, fabricate, test and evaluate candidate active heat exchanger modules for future applications to solar and conventional utility power plants were discussed. Alternative mechanizations of active heat exchange concepts were analyzed for use with heat of fusion phase change materials (PCMs) in the temperature range of 250 to 350 C. Twenty-six heat exchange concepts were reviewed, and eight were selected for detailed assessment. Two candidates were selected for small-scale experimentation: a coated tube and shell heat exchanger and a direct contact reflux boiler. A dilute eutectic mixture of sodium nitrate and sodium hydroxide was selected as the PCM from over 50 candidate inorganic salt mixtures. Based on a salt screening process, eight major component salts were selected initially for further evaluation. The most attractive major components in the temperature range of 250 to 350 C appeared to be NaNO3, NaNO2, and NaOH. Sketches of the two active heat exchange concepts selected for test are given.

Lefrois, R. T.; Mathur, A. K.

1980-04-01

289

Active heat exchange system development for latent heat thermal energy storage  

NASA Technical Reports Server (NTRS)

Five tasks to select, design, fabricate, test and evaluate candidate active heat exchanger modules for future applications to solar and conventional utility power plants were discussed. Alternative mechanizations of active heat exchange concepts were analyzed for use with heat of fusion phase change materials (PCMs) in the temperature range of 250 to 350 C. Twenty-six heat exchange concepts were reviewed, and eight were selected for detailed assessment. Two candidates were selected for small-scale experimentation: a coated tube and shell heat exchanger and a direct contact reflux boiler. A dilute eutectic mixture of sodium nitrate and sodium hydroxide was selected as the PCM from over 50 candidate inorganic salt mixtures. Based on a salt screening process, eight major component salts were selected initially for further evaluation. The most attractive major components in the temperature range of 250 to 350 C appeared to be NaNO3, NaNO2, and NaOH. Sketches of the two active heat exchange concepts selected for test are given.

Lefrois, R. T.; Mathur, A. K.

1980-01-01

290

High resolution numerical modelling of high temperature heat storage in geological media  

NASA Astrophysics Data System (ADS)

Increasing use of energy stemming from renewable sources, such as wind or solar power plants, requires development of new and improvement of existing energy storage options on different time scales. One potential storage option is high temperature heat storage with temperatures of up to 100C in the geological subsurface using borehole heat exchanger (BHE). Numerical scenario simulations are performed to assess feasibility and storage capacity and, furthermore, to predict the effects induced. To allow for accurate and reliable results, the BHE must be represented correctly and realistic in the numerical model. Therefore, a detailed model of a single BHE and the surrounding aquifer, accounting for the full geometry and component parametrisation (circulating working fluid, pipe and grout), is set up. This model setup is used to simulate an experimental data set from a laboratory sandbox by Beier et al. (2011), containing an 18 m long single U-tube BHE centered horizontally along it. Temperature curves observed in different radial distances as well as at the pipe outflow can be matched well with the model setup used, which is thus verified. Potential geological formations for high temperature heat storage are located in greater depths below fresh water aquifers that are used for drinking water. Therefore, the above model is adapted to represent a 100 m long vertical double U-tube BHE placed in an average depth of 500 m. The processes of heat transport and groundwater flow are coupled by water density and viscosity, which both depend on pressure and temperature. A sensitivity study is done to quantify the effects of the thermal parameters of grout and aquifer on the amount of heat stored and the temperature distribution in the aquifer. It was found that the amount of heat stored through the BHE is most sensitive to the heat conductivity of the aquifer. Increasing the aquifer heat conductivity by 50 % increases the amount of heat stored in the numerical model by 30 %. In contrast, only 3 % more heat can be stored in the system when increasing the grout thermal conductivity by 50 %. Temperature distribution in the aquifer is most sensitive to the thermal conductivity of the grout, resulting in higher temperatures when increasing the grout thermal conductivity. Increasing the aquifer thermal conductivity leads to higher temperatures at first and lower temperatures after a longer time period. Grout heat capacity, however, neither influences the amount of heat stored nor the temperature inside the aquifer. Occurrence and magnitude of the induced convection in the sand aquifer that surrounds the BHE depends on the given permeability as well as temperature gradients and therefore density differences in the model area. Increasing the vertical permeability from k=510-13 m2 to k=510-11 m2 results in induced convection with lower temperatures in the aquifer and a doubling of the amount of heat stored. Reference: R.A. Beier, M.D. Smith and J.D. Spitler. Reference data set for vertical borehole ground heat exchanger models and thermal response test analysis. Geothermics, 40, 79-85, (2011).

Boockmeyer, Anke; Bauer, Sebastian

2014-05-01

291

Ion-implanted PLZT ceramics: a new high-sensitivity image storage medium  

SciTech Connect

Results were presented of our studies of photoferroelectric (PFE) image storage in H- and He-ion implanted PLZT (lead lanthanum zirconate titanate) ceramics which demonstrate that the photosensitivity of PLZT can be significantly increased by ion implantation in the ceramic surface to be exposed to image light. More recently, implantations of Ar and Ar + Ne into the PLZT surface have produced much greater photosensitivity enhancement. For example, the photosensitivity after implantation with 1.5 x 10/sup 14/ 350 keV Ar/cm/sup 2/ + 1 x 10/sup 15/ 500 keV Ne/cm/sup 2/ is increased by about four orders of magnitude over that of unimplanted PLZT. Measurements indicate that the photosensitivity enhancement in ion-implanted PLZT is controlled by implantation-produced disorder which results in marked decreases in dielectric constant and dark conductivity and changes in photoconductivity of the implanted layer. The effects of Ar- and Ar + Ne-implantation are presented along with a phenomenological model which describes the enhancement in photosensitivity obtained by ion implantation. This model takes into account both light- and implantation-induced changes in conductivity and gives quantitative agreement with the measured changes in the coercive voltage V/sub c/ as a function of near-uv light intensity for both unimplanted and implanted PLZT. The model, used in conjunction with calculations of the profiles of implantation-produced disorder, has provided the information needed for co-implanting ions of different masses, e.g., Ar and Ne, to improve photosensitivity.

Peercy, P.S.; Land, C.E.

1980-01-01

292

Advanced technology thermal energy storage and heat exchange systems for solar applications: a survey of current research  

Microsoft Academic Search

A survey is presented of the advanced research and development projects underway in the U.S. in all of the known media and methods for storing and transferring thermal energy in solar applications. The technologies reviewed include innovative heat exchange and heat transport methods, advanced sensible heat storage in water, rocks, earth and combinations of these for both short term and

Michaels

1978-01-01

293

Heat-Based Dynamic Data Caching: A Load Balancing Strategy for Energy-Efficient Parallel Storage Systems with Buffer Disks  

E-print Network

Heat-Based Dynamic Data Caching: A Load Balancing Strategy for Energy- Efficient Parallel Storage to conserve energy. A heat-based dynamic data caching strategy is developed to improve performance. The BUD while making buffer disks a potential performance bottleneck. The heat-based data caching strategy aims

Qin, Xiao

294

Estimated heats of fusion of fluoride salt mixtures suitable for thermal energy storage applications  

NASA Technical Reports Server (NTRS)

The heats of fusion of several fluoride salt mixtures with melting points greater than 973 K were estimated from a coupled analysis of the available thermodynamic data and phase diagrams. Simple binary eutectic systems with and without terminal solid solutions, binary eutectics with congruent melting intermediate phases, and ternary eutectic systems were considered. Several combinations of salts were identified, most notable the eutectics LiF-22CaF2 and NaF-60MgF2 which melt at 1039 and 1273 K respectively which posses relatively high heats of fusion/gm (greater than 0.7 kJ/g). Such systems would seemingly be ideal candidates for the light weight, high energy storage media required by the thermal energy storage unit in advanced solar dynamic power systems envisioned for the future space missions.

Misra, A. K.; Whittenberger, J. D.

1986-01-01

295

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

296

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

297

Thermal energy storage material thermophysical property measurement and heat transfer impact  

Microsoft Academic Search

The thermophysical properties of salts having potential for thermal energy storage to provide peaking energy in conventional electric utility power plants were investigated. The power plants studied were the pressurized water reactor, boiling water reactor, supercritical steam reactor, and high temperature gas reactor. The salts considered were LiNO3, 63LiOH\\/37 LiCl eutectic, LiOH, and Na2B4O7. The thermal conductivity, specific heat (including

R. P. Tye; J. G. Bourne; A. O. Destarlais

1976-01-01

298

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

299

One-Step Quenching and Partitioning Heat Treatment of Medium Carbon Low Alloy Steel  

NASA Astrophysics Data System (ADS)

This paper presents the results of novel one-step quenching and partitioning (Q&P) heat treatment conducted on medium carbon low alloy steel sheet. Samples were austenitised at 1193 K followed by interrupted quenching at 473 K for different partitioning times and finally they were quenched in water. Dilatometry was employed for selection of treatment temperatures. Optical and scanning electron microscopy was carried out to examine the microstructural changes. Volume fraction of retained austenite was measured by x-ray diffraction technique. Resulting microstructures were correlated with the mechanical properties such hardness, tensile strength, elongation, impact absorbed energy, etc. The notch tensile and fracture toughness properties of Q&P steels are still lacking therefore notch tensile strength and plain strain fracture toughness tests were conducted and results are reported here. Results of Q&P treatments were also compared with the properties obtained by conventional Quenching and Tempering (Q&T) and normalizing treatments. Optimum strength-ductility balance of about 2000 MPa tensile strength with 11% elongation was achieved in samples quenched at 473 K and isothermally partitioned for 100 s. Higher ductility of Q&P steel was attributed to the presence of 6.8% film-type interlath retained austenite. Fine-grained martensitic structure with high density of interphase boundaries imparted ultrahigh strength. It was further noted that the impact toughness, notch tensile strength and fracture toughness of 1000 s partitioned samples was higher than 100 s partitioned samples. Possible reasons for high toughness are synergetic effect of recovery of dislocations, partial loss of martensite tetragonality and precipitation of fine transition carbides.

Tariq, Fawad; Baloch, Rasheed Ahmed

2014-05-01

300

Perpendicular magnetization reversal mechanism of functional FePt films for magnetic storage medium  

NASA Astrophysics Data System (ADS)

Magnetization reversal mechanism and related surface morphology of functional FePt(001) alloy films with large perpendicular magnetic anisotropy have been explored by alternate-atomic-layer deposition onto Pt/MgO(100) substrates via electron beam evaporation, and all evaporated films have been kept at in-situ substrate heating temperature of 400 C. The FePt alloy film was composed of ultrathin [Fe (0.5 nm)/Pt (0.5 nm)]n Fe/Pt multilayer structures. The corresponding thickness of multilayer films was controlled by the periodic bilayer numbers (n) and varied in the range from 15 nm (n = 15) to 30 nm (n = 30). The surface topography was observed and varied from granular-like island to continuous microstructures with increasing the periodic numbers of Fe/Pt bilayer films. The measurement of angular dependent coercivity showed a tendency of the near rotation of reverse-domain type (n = 15) shift towards the domain-wall motion as a typical peak behavior (n = 30) with increasing the periodic bilayer numbers of Fe/Pt multilayers. On the basis of all magnetic measurements and corresponding magnetization analysis, indicating that the perpendicular magnetization reversal mechanism and related surface morphology of ordered FePt(001) alloy films could be systematically controlled by varying the periodic bilayer numbers accompanied with the thickness dependence.

Wei, Da-Hua; Chi, Po-Wei; Chao, Chung-Hua

2014-11-01

301

Effect of heat treatment on the storage stability of low calorie milk drinks.  

PubMed

The study was undertaken to study the effect of heat treatment on the storage stability of cardamom flavoured low calorie milk drinks (CFDs). The drinks prepared by replacing sugar with sucralose and adding inulin in milk of 0.5% fat and 8.5% milk solid-not-fat were subjected to pasteurization and sterilization and stored at refrigeration and room temperature, respectively. The stored samples were evaluated for changes in physico-chemical and sensory attributes at regular intervals. In pasteurized drinks, the total solids (TS) and pH declined while the total soluble solids (TSS), titratable acidity and viscosity increased significantly (p?storage. A significant reduction in the flavour and body and mouthfeel scores was observed. Standard plate count (SPC) increased in both control and low calorie drinks with storage period. In sterilized CFDs, TS and TSS were not affected appreciably whereas titratable acidity increased and viscosity decreased significantly (p?storage. Though the sensory scores also declined with storage, the drinks obtained high acceptability scores even after 150days of storage at room temperature. However, the changes in colour components (L, a and b values) indicated increased browning in the drinks with storage time. SPC was not detected until 120days in control and 135days in low calorie drink. Yeast and molds were not evident until 135days in control and 150days in low calorie drink. The shelf life was found to be 10 and 150days of pasteurized and sterilized CFDs at refrigeration and room temperature, respectively. PMID:25190842

Mittal, Shikha; Bajwa, Usha

2014-09-01

302

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

303

Evaluation of enrichment, storage, and age of blood agar medium in relation to its ability to support growth of anaerobic bacteria.  

PubMed

By measuring the colony size of a variety of anaerobic bacteria isolated from clinical specimens, an evaluation was made of the benefits derived from the addition of several enrichments to blood agar medium commonly used for the growth of anaerobes. Similar methods were used to study the effects of various storage conditions and age of the medium. The results were compared with those obtained on freshly prepared and enriched blood agar plates as well as commercially available blood agar plates. Freshly prepared and enriched blood agar was found to give substantially larger colonies than could be grown on commercially obtained blood agar plates when both were inoculated and incubated under identical conditions. Storage of plating media under CO2 for periods of up to 72 h had only a minor effect on the growth of the anaerobic bacteria studied, but longer periods of storage under CO2 resulted in a less efficient plating medium. Nonenriched brain heart infusion (BHI) was found to be a better basal medium than Trypticase soy agar (TSA) medium. Colony size on fully enriched BHI blood agar plates was greater than nonenriched BHI greater than nonenriched TSA greater than commercially prepared nonenriched TSA plates. The data suggest that freshness of the plates may be as important as using rich media. PMID:11226

Hanson, C W; Martin, W J

1976-11-01

304

Radiant heat transfer in a closed system of semiopaque bodies separated by an emitting and absorbing gas medium  

SciTech Connect

The extensive use of films and plastics in the construction of modern structures evokes the necessity of solving radiant heat transfer problems relative to thermal radiation. Moreover, the space of these structures is filled with nonisothermal media emitting and absorbing thermal radiation since triatomic gases are usually contained therein. The cause of the nonisothermal nature of the gas space is the different temperature of its bounding surface. The radiant heat transfer problem for this system is solved, in this paper, by a model based on a closed emitting system bounded by a nonisothermal semiopaque shell with the absorption and emission of such a nonisothermal gas medium taken into account.

Gorshenin, V.P.

1988-08-01

305

Assessment and Prediction of the Thermal Performance of a Centralized Latent Heat Thermal Energy Storage Utilizing Artificial Neural Network  

E-print Network

A simulation tool is developed to analyze the thermal performance of a centralized latent heat thermal energy storage system (LHTES) using computational fluid dynamics (CFD). The LHTES system is integrated with a mechanical ventilation system...

El-Sawi, A.; Haghighat, F.; Akbari, H.

2013-01-01

306

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

307

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 xy plane, at a distance l beneath the base side of the square.

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

2008-01-01

308

Modeling of arbitrary-shaped specific and latent heat curves in phase-change storage simulation routines  

Microsoft Academic Search

In solar heat storage, use is often made of the latent heat of phase-change materials (PCM) with a wide temperature transition range. In this paper the heat withdrawal of a slab of such a phase-change material after a step-wise change in wall temperature, and as a function of the shape of the specific and latent heat curve, has been studied

G. C. J. Bart; P. C. van der Laag

1990-01-01

309

Retrospective dosimetry: dose evaluation using unheated and heated quartz from a radioactive waste storage building.  

PubMed

In the assessment of dose received from a nuclear accident, considerable attention has been paid to retrospective dosimetry using heated materials such as household ceramics and bricks. However, unheated materials such as mortar and concrete are more commonly found in industrial sites and particularly in nuclear installations. These materials contain natural dosemeters such as quartz, which usually is less sensitive than its heated counterpart. The potential of quartz extracted from mortar in a wall of a low-level radioactive-waste storage facility containing distributed sources of 60Co and 137Cs has been investigated. Dose-depth proliles based on small aliquots and single grains from the quartz extracted from the mortar samples are reported here. These are compared with results from heated quartz and polymineral fine grains extracted from an adjacent brick, and the integrated dose recorded by environmental TLDs. PMID:12382805

Jain, M; Btter-Jensen, L; Murray, A S; Jungner, H

2002-01-01

310

Insulin mediates the linkage acceleration of muscle protein synthesis, thermogenesis, and heat storage by amino acids.  

PubMed

Amino acid (AA) administration can stimulate heat accumulation in the body, as especially found under anesthetic conditions. To test our hypothesis that marked rise in plasma insulin concentrations following AA administration plays an important role in the heat storage, we intravenously administered either a balanced AA mixture or saline over 3 h, both with and without a primed-constant infusion of somatostatin in propofol-anesthetized rats. Rats on AA but lacking marked rise in plasma insulin by somatostatin treatment failed to show: attenuation of fall in core body temperature; partial increases in oxygen consumption; and stimulated muscle protein synthesis. Furthermore, the AA's stimulatory effects on phosphorylation of mTOR, 4E-BP1, and S6K1 were partially blocked by somatostatin. Our findings strongly suggest that the marked rise in insulin following AA administration promote translation initiation activities and stimulate muscle protein synthesis, which facilitates heat accumulation in the body. PMID:19523452

Yamaoka, Ippei; Doi, Masako; Kawano, Yuichi; Nakayama, Mitsuo; Watanabe, Yosuke; Oba, Kanae; Sugahara, Kunio; Yoshizawa, Fumiaki

2009-08-14

311

Calorimetric studies of thermochemical heat storage materials based on mixtures of MgSO 4 and MgCl 2  

Microsoft Academic Search

Attapulgite granulate impregnated with mixtures of MgSO4 and MgCl2 hydrates was investigated for suitability as a composite thermal energy storage material. These mixtures were chosen because of the very different deliquescence relative humidities of the salts. The thermochemical heat storage of these materials was characterized by measurements of isothermal heat of sorption and thermogravimetry (TG). The salt mixtures showed a

K. Posern; Ch. Kaps

2010-01-01

312

Experimental investigation of heat and mass transfer in storage without drainage of cryogenic products to supercritical pressure  

Microsoft Academic Search

Investigation of the special features of storage without drainage of liquid nitrogen to supercritical pressure and analysis of the literature data on the examination of the processes of storage of cryogenic liquids to pressures of p = 0.4-0.6 MPa showed that the thermal stratification of the liquid which occurs during free convective heat exchange and heating of the two-phase system

A. M. Domashenko; I. M. Agafonov

1984-01-01

313

Annual collection and storage of solar energy for the heating of buildings. Final report, May 1976September 1978  

Microsoft Academic Search

An experimental system for annual collection and storage of solar energy was constructed at the University of Virginia and operated for an annual cycle from February 1977 through January 1978. The experimental system consists of a hot water storage pool which stores energy in the form of sensible heat. The top of the pool is sealed with a solar collector

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

1980-01-01

314

Performance study of underground thermal storage in a solar-ground coupled heat pump system for residential buildings  

Microsoft Academic Search

This paper is performed to analyze the performance of underground thermal storage in a solar-ground coupled heat pump system (SGCHPS) for residential building. Based on the experimental results, the system performance during a longer period is simulated by the unit modeling, and its parametric effects are discussed. The results show that the performance of underground thermal storage of SGCHPS depends

Huajun Wang; Chengying Qi

2008-01-01

315

Bacterial safety of flash-heated and unheated expressed breastmilk during storage.  

PubMed

Heat-treated breastmilk is one infant-feeding option recommended by the WHO to reduce mother-to-child transmission of HIV in developing countries. Flash-heat, a simple pasteurization method that a mother could perform in her home, has been shown to inactivate cell-free HIV-1. Since heating may affect the naturally occurring antimicrobial properties found in breastmilk, storing heated breastmilk may present a safety issue in resource-poor settings due to lack of refrigeration and potential contamination. To address this, we investigated the ability of flash-heat to eliminate bacteria and to prevent growth over time compared with unheated breastmilk. We collected breastmilk samples from 38 HIV positive mothers in South Africa and aliquoted them to flash-heated and unheated controls. Samples were stored at room temperature for 0, 2, 6 and 8 h and then plated and incubated for 24 h at 37 degrees C in CO(2). We performed total colony counts and identified Escherichia coli, Staphylocuccus aureus and Group A and Group B streptococci. Unheated samples had a significantly higher number of samples positive for bacterial growth at each time point (p < 0.0001), as well as mean colony-forming units (CFU)/ml in those samples that were positive at each time point (p < 0.0001). In addition, unheated samples had a significantly higher rate of bacterial propagation over time than flash-heated samples when comparing log values of CFU/ml across 0-8 h (p < 0.005). No pathogenic growth was observed in the flash-heated samples, while the unheated samples showed growth of E. coli (n = 1) and S. aureus (n = 6). Our data suggest that storage of flash-heated breastmilk is safe at room temperature for up to 8 h. PMID:17005732

Israel-Ballard, K; Coutsoudis, A; Chantry, C J; Sturm, A W; Karim, F; Sibeko, L; Abrams, B

2006-12-01

316

Accumulation of plant small heat-stress proteins in storage organs.  

PubMed

Plant small heat-stress proteins (sHSPs) have been shown to be expressed not only after exposure to elevated temperatures, but also at particular developmental stages such as embryogenesis, microsporogenesis, and fruit maturation. This paper presents new data on the occurrence of sHSPs in vegetative tissues, their tissue-specific distribution, and cellular localization. We have found sHSPs in 1-year-old twigs of Acer platanoides L. and Sambucus nigra L. and in the liana Aristolochia macrophylla Lamk. exclusively in the winter months. In tendrils of Aristolochia, sHSPs were localized in vascular cambium cells. After budding, in spring, these proteins were no longer present. Furthermore, accumulation of sHSPs was demonstrated in tubers and bulbs of Allium cepa L., Amaryllis ( Hippeastrum hybridum hort.), Crocus albiflorus L., Hyacinthus orientalis L., Narcissus pseudonarcissus L., Tulipa gesneriana L., and Solanum tuberosum L. (potato). In potato tubers and bulb scales of Narcissus the stress proteins were localized in the central vacuoles of storage parenchyma cells. In order to obtain more information on a possible functional correlation between storage proteins and sHSPs, the accumulation of both types of protein in tobacco seeds during seed ripening and germination was monitored. The expression of sHSPs and globulins started simultaneously at about the 17th day after anthesis. During seed germination the sHSPs disappeared in parallel with the storage proteins. Furthermore, in embryos of transgenic tobacco plants, which do not contain any protein bodies or storage proteins, no sHSPs were found. Thus, the occurrence of sHSPs in perennial plant storage organs seems to be associated with the presence of storage proteins. PMID:12029471

Lubaretz, Olga; Zur Nieden, Uta

2002-06-01

317

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

318

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

319

Simulation and optimization study of a solar seasonal storage district heating system: the Fox River Valley case study  

SciTech Connect

A central solar-heating plant with seasonal heat storage in a deep underground aquifer is designed by means of a solar-seasonal-storage-system simulation code based on the Solar Energy Research Institute (SERI) code for Solar Annual Storage Simulation (SASS). This Solar Seasonal Storage Plant is designed to supply close to 100% of the annual heating and domestic-hot-water (DHW) load of a hypothetical new community, the Fox River Valley Project, for a location in Madison, Wisconsin. Some analyses are also carried out for Boston, Massachusetts and Copenhagen, Denmark, as an indication of weather and insolation effects. Analyses are conducted for five different types of solar collectors, and for an alternate system utilizing seasonal storage in a large water tank. Predicted seasonal performance and system and storage costs are calculated. To provide some validation of the SASS results, a simulation of the solar system with seasonal storage in a large water tank is also carried out with a modified version of the Swedish Solar Seasonal Storage Code MINSUN.

Michaels, A.I.; Sillman, S.; Baylin, F.; Bankston, C.A.

1983-05-01

320

Heat Storage and Energy Closure in Two Tropical Montane Forests in Hawaii  

NASA Astrophysics Data System (ADS)

To date, eddy covariance observations of evapotranspiration (ET) in tropical rainforest ecosystems are limited and thorough assessments of such observations are rare. In this study, we present a detailed evaluation of eddy covariance data collected at two sites in Hawaii Volcanoes National Park, Hawaii, for a 34 month period to evaluate the importance of biomass and air heat storage to the energy balance and determine site specific energy closure characteristics. One site is located in a native Hawaiian tropical montane forest dominated by Metrosideros polymorpha (Nahuku), while the other is located in a nearby forest (Olaa) that has been partially invaded by strawberry guava (Psidium cattleianum). Vertical and radial distribution of all biomass components were evaluated from detailed stand surveys, biomass samples, allometric relationships, wood density, fresh to dry weight ratios of plant materials, and temperature measurements of stem biomass. Total fresh biomass was estimated to be 69.8 11.7 kg m-2 and 75.9 16.6 kg m-2 at Nahuku and Olaa, respectively, and the contribution of separate biomass components to energy closure were evaluated in detail. Despite statistically similar fresh biomass between stands, energy storage was found to be significantly greater at the forest site with P. cattleianum tree invasion (Olaa) than at the native forest stand (Nahuku). The difference was attributed to a higher proportion of smaller stems at Olaa, absorbing and releasing more heat for a given mass. Inclusion of biomass and air heat storage in the energy balance improved the relative energy closure, the slope of the linear regression (forced through the origin) of the sum of latent and sensible heat fluxes measured above the canopies for each 30-minute period from 0.767 to 0.805 at Nahuku and from 0.918 to 0.997 at Olaa. The mean absolute energy imbalance, the mean of the differences between the available energy and the sum of latent and sensible heat fluxes for each 30-minute interval for a binned group of values, was also reduced for most parts of the diurnal cycle. These results indicate that it is necessary to include heat storage in energy balance investigations to reduce error in energy balance adjustments of ET. However, it was found that the relative energy closure is not constant over all environmental conditions and has complex relationships with friction velocity, atmospheric stability, and time of day. Therefore, energy closure adjustments to ET estimates should consider environmentally controlled variation in the relative and absolute energy closure in order to reduce error in estimates of land-atmosphere gas exchange. Furthermore, including all significant heat storage terms does not close the energy balance at the native forest site, which is likely due to additional site specific factors influencing the characteristics of turbulent flows over the surface.

Mudd, R. G.; Giambelluca, T. W.; Huang, M.

2012-12-01

321

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

322

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

Microsoft Academic Search

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

J. S. Francetic; K. S. Robinson

1987-01-01

323

Temperature distribution of a hot water storage tank in a simulated solar heating and cooling system  

NASA Technical Reports Server (NTRS)

A 2,300-liter hot water storage tank was studied under conditions simulating a solar heating and cooling system. The initial condition of the tank, ranging from 37 C at the bottom to 94 C at the top, represented a condition midway through the start-up period of the system. During the five-day test period, the water in the tank gradually rose in temperature but in a manner that diminished its temperature stratification. Stratification was found not to be an important factor in the operation of the particular solar system studied.

Namkoong, D.

1976-01-01

324

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, MgNi\\/Mg2NiH4, MgFe\\/Mg2FeH6 and MgCoH 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 250C to 550C in which high thermal energy

A Reiser; B Bogdanovi?; K Schlichte

2000-01-01

325

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

326

The integration of water loop heat pump and building structural thermal storage systems  

SciTech Connect

Many commercial buildings need heat in one part and, at the same time, cooling in another part. Even more common is the need for heating during one part of the day and cooling during another in the same spaces. If that energy could be shifted or stored for later use, significant energy might be saved. If a building's heating and cooling subsystems could be integrated with the building's structural mass and used to collect, store, and deliver energy, the energy might be save cost-effectively. To explore this opportunity, researchers at the Pacific Northwest Laboratory (PNL) examined the thermal interactions between the heating, ventilating, and air-conditioning (HVAC) system and the structure of a commercial building. Computer models were developed to simulate the interactions in an existing building located in Seattle, Washington, to determine how these building subsystems could be integrated to improve energy efficiency. The HVAC subsystems in the existing building were modeled. These subsystems consist of decentralized water-source heat pumps (WSHP) in a closed water loop, connected to cooling towers for heat rejection during cooling mode and boilers to augment heating. An initial base case'' computer model of the Seattle building, as-built, was developed. Metered data available for the building were used to calibrate this model to ensure that the analysis would provide information that closely reflected the operation of a real building. The HVAC system and building structure were integrated in the model using the concrete floor slabs as thermal storage media. The slabs may be actively charged during off-peak periods with the chilled water in the loop and then either actively or passively discharged into the conditioned space during peak periods. 21 refs., 37 figs., 17 tabs.

Marseille, T.J.; Schliesing, J.S.

1991-10-01

327

Heat island intensity with different meteorological conditions in a medium-sized town: Szeged, Hungary  

Microsoft Academic Search

An analysis of the effects of the townSzeged, Hungary, on minimum temperatures between 1978 and 1980 is presented. The characteristics of the urban heat island effect were examined by revelation of the relationships between heat island intensity and macrosynoptic types, cloudiness, wind speed as well as the combination of cloud amount and wind speed. Anticyclonic weather situations, little or no

J. Unger

1996-01-01

328

28 To Order, Call or Shop Online at omega.comSM MEDIUM TEMPERATURE HEATING TAPES  

E-print Network

insulated with braided fiberglass and knitted into flat tape with fiberglass yarn. These tapes Heating Elements: 36-40 gage finely stranded resistance wire Heating Elements Insulation: Double braided fiberglass yarn Dielectric Strength: In excess of 2000V Lead Wires: 16 AWG high temperature 600V silicone

Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

329

Medium-Pressure Hydrogen-Oxygen Combustion Turbine Systems for Utilization of Industrial Waste Heat  

NASA Astrophysics Data System (ADS)

Recovery of waste heat is an effective means of achieving energy conservation, and the total amount of industrial waste heat is still notable. However, the value of waste heat as an energy source is low (low exergy). Its utilization therefore requires larger recovery systems with increased costs. The concept of introducing a second, high-quality heat source in the form of H2-O2 combustion in order to improve the system's performance is presented here. System analysis of the combination effect (higher output from combined than from separate sources) was conducted. The investigation results show that the systems under consideration have the potential for significant merits under moderate conditions. The proposed combination of low- and high-quality heat sources also permits reductions in the system size and cost.

Furutani, Hirohide; Uzunow, Nikolaj

330

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

SciTech Connect

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 experiments with a high-current glow discharge in D{sub 2}, Xe and Kr, when using preliminary deuterium-charged Pd and Ti cathode samples are given. The excess heat power up to 10-15 W and efficiency up to 150 % was recorded under the experiments for Pd cathode samples in D{sub 2} discharge. The excess heat power up to 5 W and efficiency up to 150 % was recorded for the preliminary deuterium-charged Pd cathode samples in Xe and Kr discharges. At the same time the excess heat power was not observed for pure Pd cathode samples in Xe, Kr discharges. Forming the impurity nuclides ({sup 7}Li, {sup 13}C, {sup 15}N, {sup 20}Ne, {sup 29}Si, {sup 44}Ca, {sup 48}Ca, {sup 56}Fe, {sup 57}Fe, {sup 59}Co, {sup 64}Zn, {sup 66}Zn, {sup 75}As, {sup 107}Ag, {sup 109}Ag, {sup 110}Cg, {sup 111}Cg, {sup 112}Cg, {sup 114}Cg, {sup 115}In) with the efficiency up to 10{sup 13} atoms/s was recorded. Large deviation of the registered isotopes relation from the natural relation of these elements isotopes was observed. The soft X-ray radiation from the solid-state cathode medium with the intensity up to 0.01 Gy/s was recorded under the experiments with the discharge in H{sub 2}, D{sub 2}, Ar, Xe, Kr. The X-ray radiation was observed as bursts (up to 10{sup 6} photons in a burst and up to 10{sup 5} bursts a second) during the discharge burning and within 100 ms after turning off the discharge current. The results of the X-ray radiation registration showed that the exited energy levels having the lifetime up to 100 ms and more and the energy of 1.2 - 1.8 keV existed in the solid medium. The possible mechanism of producing the excess heat power and products of nuclear transmutation reactions in the solid medium with the exited energy levels was considered. (author)

Karabut, A.B. [FSUE 'LUCH', 24 Zheleznodorozhnaya St, Podolsk, Moscow Region, 142100 (Russian Federation)

2004-07-01

331

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

332

Non-Darcy fully developed mixed convection in a porous medium channel with heat generation/absorption and hydromagnetic effects  

SciTech Connect

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 walls of the channel prescribed as isothermal-isothermal, isothermal-isoflux, and isoflux-isothermal. Analytical expressions for the velocity and the temperature profiles in the channel as well as for the mass flow rate, friction factor, and heat carried out by the fluid in the channel are developed for special cases of the problem. Conditions for the occurrence of fluid backflow zones are reported. The fully nonlinear governing equations are solved numerically by an implicit finite difference method. Favorable comparisons with the developed analytical results and previously published work are performed. Graphical results of the closed-form and numerical results are reported for various parametric conditions to illustrate special features of the solution. Mixed convection flow of an electrically conducting and heat-generating/absorbing fluid in a porous medium channel in the presence of a magnetic field is of special technical significance because of its frequent occurrence in many industrial applications such as geothermal reservoirs, cooling of nuclear reactors, thermal insulation, and others.

Chamkha, A.J. [Kuwait Univ., Safat (Kuwait). Dept. of Mechanical and Industrial Engineering

1997-11-07

333

Heating of the Hot Intergalactic Medium by Powerful Radio Galaxies and Associated High Energy Gamma-Ray Emission  

E-print Network

There is increasing evidence that some heating mechanism in addition to gravitational shock heating has been important for the hot gas inside clusters and groups of galaxies, as indicated by their observed X-ray scaling properties. While supernovae are the most obvious candidate heating sources, a number of recent studies have suggested that they may be energetically insufficient. Here we consider high-power, FRII radio galaxies and shock heating of the intracluster medium (ICM, including the case of the intergalactic medium prior to cluster formation) by their large-scale jets. Based on the observed statistics of radio galaxies in clusters and their evolution, along with the most reasonable assumptions, it is shown that they can provide the ICM with excess specific energies of 1--2 keV per particle, mainly during the redshift interval $z \\sim 1-3$. This naturally meets the requirements of cluster evolution models with non-gravitational feedback in accounting for the observed deviations in the X-ray luminosity-temperature relation. In contrast to supernovae, such large-scale jets deposit their energy directly into the low density ICM outside galaxies, and are much less susceptible to radiative losses. As a clear and potentially decisive test of this scenario, we propose the observation of `prompt' high energy gamma-rays emitted by shock-accelerated, non-thermal electrons during the epoch of ICM heating by radio galaxies, which may be feasible with the {\\it GLAST} satellite. Implications for recent detections of excess hard X-rays from groups are also discussed.

Susumu Inoue; Shin Sasaki

2001-06-11

334

Energy storage and heating measurements in flashlamp-pumped Cr:Nd:GSGG and Nd:YAG  

Microsoft Academic Search

The authors experimentally measured the energy stored and the heat generated in flashlamp-pumped Cr:Nd:GSGG for three Cr\\/sup 3+\\/ concentrations in the range of 1 - 2 x 10²° ions\\/cm³. They find that the energy storage efficiency in these samples is 1.7 times greater than that of our Nd:YAG sample, and the normalized heating parameter chi, defined as the heat deposited

D. S. Sumida; D. A. Rockwell; M. S. Mangir

1988-01-01

335

Applications of thermal energy storage to process heat and waste heat recovery in the iron and steel industry  

NASA Technical Reports Server (NTRS)

The system identified operates from the primary arc furnace evacuation system as a heat source. Energy from the fume stream is stored as sensible energy in a solid medium (packed bed). A steam-driven turbine is arranged to generate power for peak shaving. A parametric design approach is presented since the overall system design, at optimum payback is strongly dependent upon the nature of the electric pricing structure. The scope of the project was limited to consideration of available technology so that industry-wide application could be achieved by 1985. A search of the literature, coupled with interviews with representatives of major steel producers, served as the means whereby the techniques and technologies indicated for the specific site are extrapolated to the industry as a whole and to the 1985 time frame. The conclusion of the study is that by 1985, a national yearly savings of 1.9 million barrels of oil could be realized through recovery of waste heat from primary arc furnace fume gases on an industry-wide basis. Economic studies indicate that the proposed system has a plant payback time of approximately 5 years.

Katter, L. B.; Peterson, D. J.

1978-01-01

336

Microencapsulated PCM slurries for heat transfer and energy storage in spacecraft systems  

NASA Astrophysics Data System (ADS)

The technical feasibility for providing significantly enhanced heat transport and storage as well as improved thermal control has been investigated during several Small Business Innovative Research (SBIR) programs for NASA, the United States Air Force (USAF), and the Strategic Defense Initiative Organization (SDIO) using microencapsulated phase change materials (PCMs) in both aqueous and nonaqueous two-component slurries. In the program for SDIO, novel two-component coolant fluids were prepared and successfully tested at both low (300 K) and intermediate temperatures (460 to 700 K). The two-component fluid slurries of microencapsulated PCMs included organic particles in aqueous and nonaqueous liquids, as well as microencapsulated metals that potentially could be carried by liquid metals or used as powdered heat sinks. Simulation and experimental studies showed that such active cooling systems could be designed and operated with enhancements of heat capacity that exceeded 10 times or 1000 percent that for the base fluid along with significant enhancement in the fluid's heat capacity. Furthermore, this enhancement provided essentially isothermal conditions throughout the pumped primary coolant fluid loop. The results suggest that together with much higher fluid thermal capacity, greater uniformity of temperature is achievable with such fluids, and that significant reductions in pumping power, system size, and system mass are also possible.

Colvin, David P.; Mulligan, James C.; Bryant, Yvonne G.; Duncan, John L.; Gravely, Benjamin T.

337

Microencapsulated PCM slurries for heat transfer and energy storage in spacecraft systems  

NASA Technical Reports Server (NTRS)

The technical feasibility for providing significantly enhanced heat transport and storage as well as improved thermal control has been investigated during several Small Business Innovative Research (SBIR) programs for NASA, the United States Air Force (USAF), and the Strategic Defense Initiative Organization (SDIO) using microencapsulated phase change materials (PCMs) in both aqueous and nonaqueous two-component slurries. In the program for SDIO, novel two-component coolant fluids were prepared and successfully tested at both low (300 K) and intermediate temperatures (460 to 700 K). The two-component fluid slurries of microencapsulated PCMs included organic particles in aqueous and nonaqueous liquids, as well as microencapsulated metals that potentially could be carried by liquid metals or used as powdered heat sinks. Simulation and experimental studies showed that such active cooling systems could be designed and operated with enhancements of heat capacity that exceeded 10 times or 1000 percent that for the base fluid along with significant enhancement in the fluid's heat capacity. Furthermore, this enhancement provided essentially isothermal conditions throughout the pumped primary coolant fluid loop. The results suggest that together with much higher fluid thermal capacity, greater uniformity of temperature is achievable with such fluids, and that significant reductions in pumping power, system size, and system mass are also possible.

Colvin, David P.; Mulligan, James C.; Bryant, Yvonne G.; Duncan, John L.; Gravely, Benjamin T.

1992-01-01

338

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

339

Dimensional stability and creep behavior of heat-treated exterior medium density fiberboard  

Microsoft Academic Search

A series of commercial phenol-formaldehyde bonded MDF panels were exposed to a post-manufacture heat-treatment\\u000a at various temperatures and durations using a hot press and just enough pressure to ensure firm contact\\u000a between the panel and the press platens. Physical properties and static flexural strengths of the post\\u000a heat-treated MDF panels were evaluated according to ASTM D 1037 (2002). The results

Nadir Ayrilmis; Theodore L. Laufenberg; Jerrold E. Winandy

2009-01-01

340

Domestic olivine versus magnesite as a thermal energy storage material: Performance comparisons for electrically heated room-size units in accordance with ASHRAE standard 94.2  

NASA Astrophysics Data System (ADS)

Electrically heated thermal energy storage (TES) heaters employing high heat capacity ceramic refractories for sensible heat storage have been in use in Europe for several years. With these heaters, low cost off peak electrical energy is stored by heating a storage core composed of ceramic material to approximately 800 C. During the peak period, no electrical energy is used as the building heating needs are supplied by extracting the stored heat from the core by forced air circulation. Recently significant interest in the use of off peak TES units in the US has occurred, leading to the search for a domestic supply of high heat capacity ceramic refractory material. North Carolina's extensive but under utilized supply of refractory grade olivine has been proposed as a source of storage material for these units. In this paper, the suitability of North Carolina olivine for heat storage applications is assessed by comparing its thermal performance with that of European materials.

Laster, W. R.; Schoenhals, R. J.; Gay, B. M.; Palmour, H., III

1982-05-01

341

Recrystallization of medium-carbon steel under nonequilibrium conditions of short-term heating to a temperature above Ac1  

NASA Astrophysics Data System (ADS)

The phase recrystallization of medium-carbon steel with the initial structure of lamellar pearlite in the process of short-term heating to different temperatures above Ac1 and subsequent cooling has been studied. The structure of steel formed under the nonequilibrium conditions corresponding to the decomposition of supercooled austenite has been described. It has been shown that the changes in the structure and phase composition that arise during this treatment have a noticeable effect on the characteristics of the deformation behavior of the material determined based on the results of dynamic indentation.

Urtsev, V. N.; Yakovleva, I. L.; Tereshchenko, N. A.; Shmakov, A. V.; Murikov, S. A.; Degtyarev, V. N.

2014-09-01

342

Transient Heat Storage Characteristics on Horizontal Rectangular Enclosures Filled with Fluidity Slurry of Micro-encapsulated Phase-change-material Dispersed in Water  

Microsoft Academic Search

A two-dimensional numerical simulation of heat storage behavior by natural convection in rectangular enclosures heated from below has been conducted with fluidity slurry composed of micro-encapsulated fine phase-change-material (PCM) and water. Both heat storage and heat transfer characteristics were discussed with micro-encapsulated PCM slurry, which exhibited the pseudoplastic non-Newtonian fluid behavior and a peak value in the specific heat capacity

Hideo Inaba; Yanlai Zhang; Akihiko Horibe

2006-01-01

343

Natural convective heat transfer in a fluid saturated variable porosity medium  

Microsoft Academic Search

A generalised non-Darcian porous medium model for natural convective flow has been developed taking into account linear and non-linear matrix drag components as well as the inertial and viscous forces within the fluid. The results of the general model have been validated with the help of experimental data and compared with the various non-Darcy porous media model predictions reported in

P. Nithiarasu; K. N. Seetharamu; T. Sundararajan

1997-01-01

344

Numerical study of a nuclear fuel element dissipating fission heat into its surrounding fluid medium  

Microsoft Academic Search

The objective of the present work is twofold the first to establish the criterion for the boundary layer solution to be accurate enough in the study of conjugate heat transfer problem associated with a rectangular nuclear fuel element washed by upward moving coolant and the second to predict the critical thermal performance characteristics of the fuel element with uniform

M. K. Ramis; G. Jilani

2009-01-01

345

Interaction of mixed convection in two-sided lid driven differentially heated square enclosure with radiation in presence of participating medium  

Microsoft Academic Search

The current study addresses the mathematical modeling aspects of transport phenomena in steady, two-dimensional, laminar flow accompanied by heat transfer in a lid-driven differentially heated cavity in presence of radiatively absorbing, emitting and scattering gray medium. The walls of the enclosure are considered to be opaque, diffusive and gray. Mixed convection is the outcome of the interaction of forced convection

S. K. Mahapatra; P. Nanda; A. Sarkar

2006-01-01

346

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

347

Building the intra-group medium from shock heated HI in the NGC 5903 galaxy group  

NASA Astrophysics Data System (ADS)

Observations of the famous shock in Stephan's Quintet suggest that low-mass galaxy groups may form a significant part of their IGM via shock heating of tidally stripped HI. Stephan's Quintet is, to date, unique, but we may have found a second nearby example. The NGC 5903 group hosts a 65kpc diameter diffuse ultra-steep spectrum radio source suggestive of shock emission, and a short XMM observation shows a strong correlation between a 100kpc HI filament and bright ridges of X-ray emission, indicating that the HI has been partially shock heated by a collision with the nearby elliptical NGC 5898. XMM lacks the spatial resolution to examine these complex structures, and we request a 155ks ACIS-S pointing to investigate what may be a key example of early IGM formation in a galaxy group.

O'Sullivan, Ewan

2014-09-01

348

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

E-print Network

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

Marquez Gonzalez, Mayra

2009-05-15

349

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; Bg, O. Anwar; Izani Ismail, Ahamd

2013-02-01

350

Applications of thermal energy storage to process heat storage and recovery in the paper and pulp industry  

NASA Technical Reports Server (NTRS)

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 various TES concepts evaluated for application in the process steam supply system. Constant pressure and variable pressure steam accumulators were found to be the most attractive storage concepts for this application.

Carr, J. H.; Hurley, P. J.; Martin, P. J.

1978-01-01

351

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

352

Energy Conservation Through Heating/Cooling Retrofits in Small and Medium-Sized Industrial Plants  

E-print Network

Engineering Department of Texas A&M University (TAMU), in College Station, Texas. The lAC at TAMU has conducted over 250 energy conservation and 20 waste management surveys since 1987. Projects that would save over $8.7 million annually (about 11... of the year, the heat can be diverted outside again by the damper system. Similar discussion applies for ECO recommended in the newspaper industry plant. For the newspaper industry, the estimated energy savings from this ECO is 184.5 MCF/yr worth $890/yr...

Saman, N.; Eggebrecht, J.

353

Time resolved spectra in the infrared absorption and emission from shock heated hydrocarbons. [in interstellar medium  

NASA Technical Reports Server (NTRS)

The wavelength range of a previously constructed multichannel fast recording spectrometer was extended to the mid-infrared. With the initial configuration, light intensities were recorded simultaneously with a silicon-diode array simultaneously at 20 adjacent wavelengths, each with a 20-micron time resolution. For studies in the infrared, the silicon diodes were replaced by a 20-element PbSe array of similar dimensions, cooled by a three-stage thermoelectric device. It is proposed that infrared emissions could be due to shock-heated low molecular-weight hydrocarbons. The full Swan band system appeared in time-integrated emission spectra from shock-heated C2H2; no soot was generated. At low resolution, the profiles on the high-frequency side of the black body maximum show no distinctive features. These could be fitted to Planck curves, with temperatures that declined with time from an initial high that was intermediate between T5 (no conversion) and T5(eq).

Bauer, S. H.; Borchardt, D. B.

1990-01-01

354

Uncertainty estimation in one-dimensional heat transport model for heterogeneous porous medium.  

PubMed

In many practical applications, the rates for ground water recharge and discharge are determined based on the analytical solution developed by Bredehoeft and Papadopulos (1965) to the one-dimensional steady-state heat transport equation. Groundwater flow processes are affected by the heterogeneity of subsurface systems; yet, the details of which cannot be anticipated precisely. There exists a great deal of uncertainty (variability) associated with the application of Bredehoeft and Papadopulos' solution (1965) to the field-scale heat transport problems. However, the quantification of uncertainty involved in such application has so far not been addressed, which is the objective of this wok. In addition, the influence of the statistical properties of log hydraulic conductivity field on the variability in temperature field in a heterogeneous aquifer is also investigated. The results of the analysis demonstrate that the variability (or uncertainty) in the temperature field increases with the correlation scale of the log hydraulic conductivity covariance function and the variability of temperature field also depends positively on the position. PMID:23803142

Chang, Ching-Min; Yeh, Hund-Der

2014-01-01

355

Enrichment and heating of the intracluster medium by ejection from galaxies  

NASA Technical Reports Server (NTRS)

Results of N-body + hydrodynamic simulations designed to model the formation and evolution of clusters of galaxies and intracluster gas are presented. Clusters of galaxies are the largest bound, relaxed objects in the universe. They are strong x-ray emitters; this radiation originates through thermal bremsstrahlung from a diffuse plasma filling the space between cluster galaxies, the intracluster medium or ICM. From observations, one can infer that the mass of the ICM is comparable to or greater than the mass of all the galaxies in the cluster, and that the ratio of mass in hot gas to mass in galaxies, M(sub ICM)/M(sub STARS), increases with the richness of the cluster. Spectroscopic studies of cluster x-ray emission show heavy element emission lines. While M(sub ICM)/M(sub STARS) is greater than or equal to 1 implies that most of the ICM is primordial in nature, the discovery of heavy elements indicates that some of the gas must have been processed through galaxies. Galaxy evolution thus directly impacts cluster evolution.

Metzler, Chris; Evrard, August

1993-01-01

356

Heating the Intergalactic Medium by X-Rays from Population III Binaries in High-redshift Galaxies  

NASA Astrophysics Data System (ADS)

Due to their long mean free path, X-rays are expected to have an important impact on cosmic reionization by heating and ionizing the intergalactic medium (IGM) on large scales, especially after simulations have suggested that Population III (Pop III) stars may form in pairs at redshifts as high as 20-30. We use the Pop III distribution and evolution from a self-consistent cosmological radiation hydrodynamic simulation of the formation of the first galaxies and a simple Pop III X-ray binary model to estimate their X-ray output in a high-density region larger than 100 comoving (Mpc)3. We then combine three different methodsray tracing, a one-zone model, and X-ray background modelingto investigate the X-ray propagation, intensity distribution, and long-term effects on the IGM thermal and ionization state. The efficiency and morphology of photoheating and photoionization are dependent on the photon energies. The sub-kiloelectronvolt X-rays only impact the IGM near the sources, while the kiloelectronvolt photons contribute significantly to the X-ray background and heat and ionize the IGM smoothly. The X-rays just below 1 keV are most efficient in heating and ionizing the IGM. We find that the IGM might be heated to over 100 K by z = 10 and the high-density source region might reach 104 K, limited by atomic hydrogen cooling. This may be important for predicting the 21 cm neutral hydrogen signals. On the other hand, the free electrons from X-ray ionizations are not enough to contribute significantly to the optical depth of the cosmic microwave background to the Thomson scattering.

Xu, Hao; Ahn, Kyungjin; Wise, John H.; Norman, Michael L.; O'Shea, Brian W.

2014-08-01

357

Rational design of a culture medium for the intensification of lipid storage in Chlorella sp. Performance evaluation in air-lift bioreactor.  

PubMed

An optimal medium to culture Chlorella sp., microalgae capable of storage intracellular lipids was obtained. This culture medium consists of a saline base plus carbon-energy and nitrogen sources. Significant factors exerting influence on the culture parameters were selected. Then, by applying response surface methodology coupled to desirability function, an optimal formulation, specific for the heterotrophic growth of Chlorella sp. that allows maximizing lipid concentration was obtained. During the experimental verification, the possibility of replacing commercial glucose by hydrolysates obtained from lignocellulosic materials was evaluated. Biochemical hydrolysate of corn bran allowed obtaining important improvements in lipid concentration. Finally, the optimal formulation was evaluated in an air-lift bioreactor performing a fed-batch culture. Culturing the strain in these conditions allowed rising lipid concentrations. PMID:24607464

Giordano, Pablo C; Beccaria, Alejandro J; Goicoechea, Hctor C

2014-04-01

358

Effects of the storage conditions of burdock ( Arctium lappa L.) root on the quality of heat-processed burdock sticks  

Microsoft Academic Search

Polyethylene film and corrugated cardboard were used to package and store burdock roots (Arctium lappa L.) at 2, 8, and 20C in an attempt to maintain the good appearance of heat-processed burdock sticks. The weight loss was as high as 60% of fresh weight when corrugated cardboard cartons were used for storage at 20C. However, polyethylene bag packaging or low

Megumi Ishimaru; Koichi Kagoroku; Kazuo Chachin; Yoshihiro Imahori; Yoshinori Ueda

2004-01-01

359

Numerical models for the simulation of the simultaneous heat and mass transfer during food freezing and storage  

Microsoft Academic Search

A numerical model was developed for the prediction of simultaneous heat and mass transfer during food freezing and storage. The resultant system of coupled partial differential equations, with time-varying coefficients was solved by two explicit finite-differences methods, one with constant mesh size and the other with equal volume elements. The prediction method was applied to the calculation of profiles of

A. M. Tocci; R. H. Mascheroni

1995-01-01

360

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

361

Heating and Ionization of the Primordial Intergalactic Medium by High Mass X-ray Binaries  

E-print Network

We investigate the influence of High Mass X-ray Binaries on their high redshift environments. Using a one-dimensional radiative transfer code, we predict the ionization and temperature profiles surrounding a coeval stellar population, composed of main sequence stars and HMXBs, at various times after its formation. We consider both uniform density surroundings, and a cluster embedded in a 10^8 solar mass NFW halo. HMXBs in a constant density environment produce negligible enhanced ionization because of their high-energy SEDs and short lifetimes. In this case, HMXBs only marginally contribute to the local heating rate. For NFW profiles, radiation from main sequence stars cannot prevent the initially ionized volume from recombining since it is unable to penetrate the high density galactic core. However, HMXB photons stall recombinations behind the front, keeping it partially ionized for longer. The increased electron density in these partially ionized regions promotes further cooling, resulting in lower IGM temp...

Knevitt, Gillian; Power, Chris; Bolton, James

2014-01-01

362

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

363

Annual collection and storage of solar energy for the heating of buildings, report No. 1. Progress report, May--November 1976. [Underground pool of water  

Microsoft Academic Search

A new system for the annual collection and storage of solar heated water for heating of buildings is under development at the University of Virginia. The system is composed of an energy storage sub-system which stores hot water in an underground pool and of a solar collector sub-system which acts not only to collect solar energy throughout the year but

J. T. Beard; J. W. Dickey; F. A. Iachetta; L. U. Lilleleht

1977-01-01

364

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

365

Laboratory Evaluation of Gas-Fired Tankless and Storage Water Heater Approaches to Combination Water and Space Heating  

SciTech Connect

Homebuilders are exploring more cost effective combined space and water heating systems (combo systems) with major water heater manufacturers that are offering pre-engineered forced air space heating combo systems. In this project, unlike standardized tests, laboratory tests were conducted that subjected condensing tankless and storage water heater based combo systems to realistic, coincidental space and domestic hot water loads with the following key findings: 1) The tankless combo system maintained more stable DHW and space heating temperatures than the storage combo system. 2) The tankless combo system consistently achieved better daily efficiencies (i.e. 84%-93%) than the storage combo system (i.e. 81%- 91%) when the air handler was sized adequately and adjusted properly to achieve significant condensing operation. When condensing operation was not achieved, both systems performed with lower (i.e. 75%-88%), but similar efficiencies. 3) Air handlers currently packaged with combo systems are not designed to optimize condensing operation. More research is needed to develop air handlers specifically designed for condensing water heaters. 4) System efficiencies greater than 90% were achieved only on days where continual and steady space heating loads were required with significant condensing operation. For days where heating was more intermittent, the system efficiencies fell below 90%.

Kingston, T.; Scott, S.

2013-03-01

366

Suppression of local heat flux in a turbulent magnetized intracluster medium  

NASA Astrophysics Data System (ADS)

X-ray observations of hot gas in galaxy clusters often show steeper temperature gradients across cold fronts - contact discontinuities, driven by the differential gas motions. These sharp (a few kpc wide) surface brightness/temperature discontinuities would be quickly smeared out by the electron thermal conduction in unmagnetized plasma, suggesting significant suppression of the heat flow across the discontinuities. In fact, the character of the gas flow near cold fronts is favourable for suppression of conduction by aligning magnetic field lines along the discontinuities. We argue that a similar mechanism is operating in the bulk of the gas. Generic 3D random isotropic and incompressible motions increase the temperature gradients (in some places) and at the same time suppress the local conduction by aligning the magnetic field lines perpendicular to the local temperature gradient. We show that the suppression of the effective conductivity in the bulk of the gas can be linked to the increase of the frozen magnetic field energy density. On average the rate of decay of the temperature fluctuations d/dt decreases as -1/5.

Komarov, S. V.; Churazov, E. M.; Schekochihin, A. A.; ZuHone, J. A.

2014-05-01

367

Self-Similar Solution of Self-Gravitating, Magneto-Gas Dynamic Spherical Shock Wave Propagating in a Rotating Medium with Radiation Heat Flux  

Microsoft Academic Search

Self-similar solutions for the flow behind a self-gravitating, Magneto-gas dynamic, spherical shock wave are obtained. The ambient medium is a non uniformly rotating gas of infinite electrical conductivity with uniform azimuthal magnetic field and radiation heat flux. The medium is a perfect grey gas in local thermodynamic equilibrium. The total energy of the expanding shock wave is supposed to remain

Pankaj Sharma; Vivek Kumar Sharma

2009-01-01

368

Development of a practical photochemical energy storage system. Quarterly report. [Interconversion between norbornadiene and quadricyclene for thermochemical heat storage  

Microsoft Academic Search

Research on polymeric organic sensitizers and polymeric inorganic sensitizers for the conversion of norbornadine to quadricyclene and catalysts for the conversion of quadricyclene to norbornadine is described. The interconversion of norbornadine and quadricyclene is studied for its possible use for thermochemical solar energy storage. (WHK)

R. R. Hautala; C. R. Kutal

1977-01-01

369

Energy storage  

NASA Astrophysics Data System (ADS)

Developments in the area of energy storage are characterized, with respect to theory and laboratory, by an emergence of novel concepts and technologies for storing electric energy and heat. However, there are no new commercial devices on the market. New storage batteries as basis for a wider introduction of electric cars, and latent heat storage devices, as an aid for solar technology applications, with satisfactory performance standards are not yet commercially available. Devices for the intermediate storage of electric energy for solar electric-energy systems, and for satisfying peak-load current demands in the case of public utility companies are considered. In spite of many promising novel developments, there is yet no practical alternative to the lead-acid storage battery. Attention is given to central heat storage for systems transporting heat energy, small-scale heat storage installations, and large-scale technical energy-storage systems.

Kaier, U.

1981-04-01

370

Lysosomal storage diseases and the heat shock response: convergences and therapeutic opportunities.  

PubMed

Lysosomes play a vital role in the maintenance of cellular homeostasis through the recycling of cell constituents, a key metabolic function which is highly dependent on the correct function of the lysosomal hydrolases and membrane proteins, as well as correct membrane lipid stoichiometry and composition. The critical role of lysosomal functionality is evident from the severity of the diseases in which the primary lesion is a genetically defined loss-of-function of lysosomal hydrolases or membrane proteins. This group of diseases, known as lysosomal storage diseases (LSDs), number more than 50 and are associated with severe neurodegeneration, systemic disease, and early death, with only a handful of the diseases having a therapeutic option. Another key homeostatic system is the metabolic stress response or heat shock response (HSR), which is induced in response to a number of physiological and pathological stresses, such as protein misfolding and aggregation, endoplasmic reticulum stress, oxidative stress, nutrient deprivation, elevated temperature, viral infections, and various acute traumas. Importantly, the HSR and its cardinal members of the heat shock protein 70 family has been shown to protect against a number of degenerative diseases, including severe diseases of the nervous system. The cytoprotective actions of the HSR also include processes involving the lysosomal system, such as cell death, autophagy, and protection against lysosomal membrane permeabilization, and have shown promise in a number of LSDs. This review seeks to describe the emerging understanding of the interplay between these two essential metabolic systems, the lysosomes and the HSR, with a particular focus on their potential as a therapeutic target for LSDs. PMID:24837749

Ingemann, Linda; Kirkegaard, Thomas

2014-11-01

371

Experimental study of a solar-assisted ground-coupled heat pump system with solar seasonal thermal storage in severe cold areas  

Microsoft Academic Search

This paper presents the experimental study of a solar-assisted ground-coupled heat pump system (SAGCHPS) with solar seasonal thermal storage installed in a detached house in Harbin. The solar seasonal thermal storage was conducted throughout the non-heating seasons. In summer, the soil was used as the heat sink to cool the building directly. In winter, the solar energy was used as

Xiao Wang; Maoyu Zheng; Wenyong Zhang; Shu Zhang; Tao Yang

2010-01-01

372

Heat storage properties of organic phase-change materials confined in the nanospace of mesoporous SBA-15 and CMK-3.  

PubMed

A novel type of material encapsulating phase-change materials (PCMs) is reported concerning their implication for use as thermal energy storage devices. The composites of siliceous SBA-15 or carbonaceous CMK-3 mesoporous assemblies and organic PCMs could be used to make leak-free devices that retain their capabilities over many thermal cycles for heat storage/release. A confinement effect was observed that alters the thermal properties of the encapsulated PCM, especially in CMK-3 without any similar effects in other carbon materials. PMID:24549100

Kadoono, Tomosuke; Ogura, Masaru

2014-03-28

373

Development of a practical photochemical energy storage system. Quarterly report. [Interconversion between norbornadiene and quadricyclene for thermochemical heat storage  

Microsoft Academic Search

It was previously found that the triphenylcyclopropenyl-nickel compound ((CH)CNi(CO)Br) (I, X = Br) was an active catalyst for the conversion of quadricyclene to norbornadiene. This result was of considerable interest in connection with the development of the solar energy storage system since it indicated a new type of complex of a relatively abundant metal with potentially useful catalytic properties. For

R. R. Hautala; C. R. Kutal

1977-01-01

374

Comprehensive Compressor Calorimeter Testing of Lower-GWP Alternative Refrigerants for Heat Pump and Medium Temperature Refrigeration Applications  

SciTech Connect

In response to environmental concerns raised by the use of refrigerants with high Global Warming Potential (GWP), the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) has launched an industry-wide cooperative research program, referred to as the Low-GWP Alternative Refrigerants Evaluation Program (AREP), to identify and evaluate promising alternative refrigerants for major product categories. This paper reports one of the Oak Ridge National Laboratory (ORNL) contributions to AREP. It compares performance of alternative refrigerants to that of R-410A and R-404A for heat pump and medium temperature applications, respectively. The alternatives reported in this paper are: R-32, DR-5, and L-41a for R-410A and ARM-31a, D2Y-65, L-40, and a mixture of R-32 and R-134a for R-404A. All performance comparison tests were conducted using scroll compressors of ~1.85 tons (6.5 kW) cooling capacity. Tests were conducted over a range of combinations of saturation suction and saturation discharge temperatures for both compressors. The tests showed that, in general, energy efficiency ratio (EER) and cooling capacity of R-410A alternative refrigerants were slightly lower than that of the baseline refrigerant with a moderate increases in discharge temperature. On the other hand, R-404A alternative refrigerants showed relative performance dependence on saturation suction and saturation discharge temperatures and larger increases in discharge temperature than for the R-410A alternatives. This paper summarizes the relative performance of all alternative refrigerants compared to their respective baseline.

Shrestha, Som S [ORNL] [ORNL; Sharma, Vishaldeep [ORNL] [ORNL; Abdelaziz, Omar [ORNL] [ORNL

2014-01-01

375

Technology overview of energy storage systems  

Microsoft Academic Search

A state-of-the-art review of energy storage technologies is presented. A discussion of thermal energy storage covers seasonal storage for heating and cooling, daily heating and cooling storage, storage for thermal power generation, and industrial waste heat generation. Thermochemical energy storage involves a discussion of thermochemical pipelines, yearly averaging storage and a chemical heat pump storage system. Attention is also given

C. M. Buoni; J. Gahimer

1978-01-01

376

Effect of processing by hydrostatic high pressure of two ready to heat vegetable meals and stability after refrigerated storage.  

PubMed

The effect of high pressure processing (HPP) (400 and 600?MPa for 1 and 5?min) and the stability during storage were studied in two ready to heat vegetable meals: meal A, mainly composed by pumpkin and broccoli, and meal B, mainly composed by eggplant, zucchini, chard and spinach. The treatment at 600?MPa/5?min was the most effective to reduce the initial microbial loads of the meals and maintained better the microbial safety during storage. HPP had no effect on the physico-chemical and sensory properties. HPP at 600?MPa increased the antioxidant activity of the meal A. In contrast HPP reduced the antioxidant activity of the meal B, although in general high levels of antioxidants were maintained after processing and during storage. In conclusion, treatments at 600?MPa for 5?min were the most suitable to increase the shelf-life of the meals without affecting their physico-chemical, antioxidant and sensory properties. PMID:23908392

Masegosa, Rosa; Delgado-Admez, Jonathan; Contador, Rebeca; Snchez-iguez, Francisco; Ramrez, Rosario

2014-12-01

377

Actual information storage with a recording density of 4 Tbit/in.2 in a ferroelectric recording medium  

PubMed Central

A new method to achieve real information recording with a density above 1 Tbit?in.2 in ferroelectric data storage systems is proposed. In this system, data bits were written in the form of the polarization direction, and the data were read by scanning nonlinear dielectric microscopy technique. The domain-switching characteristics of the virgin and inversely prepolarized media were compared, and the conditions of the pulse voltage for writing were optimized. As a result, actual data containing 6464 bits were recorded at an areal density of 4 Tbit?in.2. The bit error rate was evaluated to be 1.210?2. PMID:20877653

Tanaka, Kenkou; Cho, Yasuo

2010-01-01

378

Free convective heat transfer over a nonisothermal body of arbitrary shape embedded in a fluid-saturated porous medium  

SciTech Connect

The problem of free convective heat transfer from a nonisothermal two-dimensional ar axisymmetric body of arbitrary geometric configuration in a fluid-saturated porous medium was analyzed on the basis of boundary layer approximations. Upon introducing a similarity variable (which also accounts for a possible wall temperature effect on the boundary layer length scale), the governing equations for a nonisothermal body of arbitrary shape can be reduced to an ordinary differential equation which has been previously solved by Cheng and Minkowycz for a vertical flat plate with its wall temperature varying in an exponential manner. Thus, it is found that any two-dimensional or axisymmetric body possesses a corresponding class of surface wall temperature distributions which permit similarity solution. Furthermore, a more straightforward and yet sufficiently accurate approximate method based on the Karman-Pohlhausen integral relation is suggested for a general solution procedure for a Darcian fluid flow over a nonisothermal body of arbitrary shape. For illustrative purposes, computations were carried out on a vertical flat plate, horizontal ellipses, and ellipsoids with different minor-to-major axis ratios.

Nakayama, A.; Koyama, H. (Shizuoka Univ. (Japan))

1987-02-01

379

Food matrices and cell conditions influence survival of Lactobacillus rhamnosus GG under heat stresses and during storage.  

PubMed

The present study evaluated impact of moisture content and cell conditions on survival of probiotic strain, Lactobacillus rhamnosus GG, under lethal heat stresses and during long-term storage using freeze-dried cells and oils as matrices. Viable cell counts of freeze-dried L. rhamnosus GG cells suspended in oils had only 1-log-reduction after 5min at 80C and approximately 3-log-reduction after 20min, while no or very few viable cells were recorded for freeze dried cells suspended in buffer and cultured cells in oils. Surprisingly, freeze-dried cells suspended in oils still contained 4.3 to 6.7logCFU/ml after 5min at 95C. Long-term storage study indicated that freeze-dried cells suspended in oils kept viable conditions for 4months, and a loss of the viability was only 0.3 to 0.6logCFU/ml. Viable cell counts of cultured cells suspended in oils were not present after 3days to 3months. These results clearly indicate that moisture and cell conditions have a great impact on survival of probiotics under severe heat stress in processing and during long-term storage. Combination of freeze-dried cells and oils as carrier provides beneficial options to preserve viability of probiotics in food processes and storage. PMID:24480189

Endo, Akihito; Tersjrvi, Johanna; Salminen, Seppo

2014-03-17

380

Thermochemical Heat Storage for Concentrated Solar Power. Thermochemical System Reactor Dessing for Thermal Energy Storage. Phase II final Report for the Period of September 30, 2008 through April 30, 2011.  

National Technical Information Service (NTIS)

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...

2011-01-01

381

Structure and thermal properties of salicylate-based-protic ionic liquids as new heat storage media. COSMO-RS structure characterization and modeling of heat capacities.  

PubMed

During this research, we present a study on the thermal properties, such as the melting, cold crystallization, and glass transition temperatures as well as heat capacities from 293.15 K to 323.15 K of nine in-house synthesized protic ionic liquids based on the 3-(alkoxymethyl)-1H-imidazol-3-ium salicylate ([H-Im-C1OC(n)][Sal]) with n = 3-11. The 3D structures, surface charge distributions and COSMO volumes of all investigated ions are obtained by combining DFT calculations and the COSMO-RS methodology. The heat capacity data sets as a function of temperature of the 3-(alkoxymethyl)-1H-imidazol-3-ium salicylate are then predicted using the methodology originally proposed in the case of ionic liquids by Ge et al. 3-(Alkoxymethyl)-1H-imidazol-3-ium salicylate based ionic liquids present specific heat capacities higher in many cases than other ionic liquids that make them suitable as heat storage media and in heat transfer processes. It was found experimentally that the heat capacity increases linearly with increasing alkyl chain length of the alkoxymethyl group of 3-(alkoxymethyl)-1H-imidazol-3-ium salicylate as was expected and predicted using the Ge et al. method with an overall relative absolute deviation close to 3.2% for temperatures up to 323.15 K. PMID:24413748

Jacquemin, Johan; Feder-Kubis, Joanna; Zor?bski, Micha?; Grzybowska, Katarzyna; Chor??ewski, Miros?aw; Hensel-Bielwka, Stella; Zor?bski, Edward; Paluch, Marian; Dzida, Marzena

2014-02-28

382

THERMOCHEMICAL STORAGE OF LOW TEMPERATURE HEAT BY ZEOLITES; SAPO'S AND IMPREGNATED ACTIVE CARBON  

Microsoft Academic Search

The adsorption behaviour and storage properties of common and new microporous materials such as low silica X zeolites (LSX), SAPO and with CaCl2 impregnated active carbon were investigated by means of TG\\/DSC, the measurements of adsorption isotherms and using a lab-scaled storages of 1.5 L volume. Tests of common zeolites and mesoporous materials (silica gel) in a lab-scaled storages showed

J. Jnchen; E. Weilerb Ackermannb; H. Stach

383

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 nightwhen the sun is not outto 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. USFs PCMs remain stable at temperatures from 600 to 1,000C and can be used for solar thermal power storage, nuclear thermal power storage, and other applications.

None

2011-12-05

384

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

SciTech Connect

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, such as EPDM rubber, by simultaneously bonding and curing such material around the peripheral edges of the two sheets and at spaced apart, discrete areas over most of the interior areas of the sheets. In one form of the method, one of the sheets is coated with a layer of release agent, over all areas except the discrete areas and the peripheral areas so that only such uncoated areas will bond during cure. In another form, a sheet of non-adherent plastic slightly smaller than the two sheets and having holes or holidays to form the discrete areas is bonded between the two sheets. In a third form, the peripheral edges are first sealed to form a chamber, then the chamber is inflated and a forming die presses together the discrete areas only. Preferably, but not necessarily, reinforcing fibers may be employed or molded, into at least one of the uncured sheets. As articles of manufacture the absorber, or tank, each includes at least one inlet and one outlet at opposed edges of the so formed chamber. Further, the storage tank has a portion of the enclosed volume adapted to receive a heat exchanger. This is made possible by omission of the discrete bonded areas over about one-fourth of the area to the two sheets. In apparatus form, a solar absorption panel and a storage tank so formed (and interconnected inlet to outlet) are mounted back-to-back by an enclosing structure suitable for roof-top or ground-pad mounting and connection into a water system for solar heating of domestic water.

Anderson, H.M.; Negley, M.E.

1984-09-18

385

Thermal and economic assessment of ground-coupled storage for residential solar heat pump systems  

NASA Astrophysics Data System (ADS)

This study performed an analysis of ground-coupled stand-alone and series configured solar-assisted liquid-to-air heat pump systems for residences. The year-round thermal performance of these systems for space heating, space cooling, and water heating were determined by simulation and compared against non-ground-coupled solar heat pump systems as well as conventional heating and cooling systems in three geographic locations: Washington, D.C., Fort Worth, Tex., and Madison, Wis. The results indicate that without tax credits a combined solar/ground-coupled heat pump system for space heating and cooling is not cost competitive with conventional systems. Its thermal performance is considerably better than non-ground-coupled solar heat pumps in Forth Worth. Though the ground-coupled stand-alone heat pump provides 51% of the heating and cooling load with non-purchased energy in Forth Worth, its thermal performance in Washington and Madison is poor.

Choi, M. K.; Morehouse, J. H.

1980-11-01

386

Quantum-state storage and processing for polarization qubits in an inhomogeneously broadened {Lambda}-type three-level medium  

SciTech Connect

We address the propagation of a single-photon pulse with two polarization components, i.e., a polarization qubit, in an inhomogeneously broadened ''phaseonium''{Lambda}-type three-level medium. We combine some of the nontrivial propagation effects characteristic for this kind of coherently prepared systems and the controlled reversible inhomogeneous broadening technique to propose several quantum information-processing applications, such as a protocol for polarization qubit filtering and sieving as well as a tunable polarization beam splitter. Moreover, we show that by imposing a spatial variation of the atomic coherence phase, an efficient quantum memory for the incident polarization qubit can be also implemented in {Lambda}-type three-level systems.

Viscor, D.; Ferraro, A.; Mompart, J.; Ahufinger, V. [Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Loiko, Yu. [Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Institute of Physics, National Academy of Sciences of Belarus, Nezalezhnasty Avenue 68, 220072 Minsk (Belarus)

2011-10-15

387

Review of Solar Thermal Storage Techniques and Associated Heat Transfer Technologies  

Microsoft Academic Search

Thermal energy storage is a key component of solar power plants if dispatchability is required. On the other hand, although different systems and many materials are available, only a few plants in the world have tested thermal energy storage systems. Here, all materials considered in literature and\\/or used in real plants are listed, the different systems are described and analyzed,

Luisa F. Cabeza; Cristian Sole; Albert Castell; Eduard Oro; Antoni Gil

2012-01-01

388

Thermal analysis of the position of the freezing front around an LNG in-ground storage tank with a heat barrier  

NASA Astrophysics Data System (ADS)

A technique of controlling the extent of the freezing zone created by in ground liquefied natural gas storage tanks by installing a heat barrier is described. The freezing conditions around three representative tanks after operating the system were compared.

Watanabe, O.; Tanaka, M.

389

Comparison of Solutions from Parabolic and Hyperbolic Models for Transient Heat Conduction in Semi-Infinite Medium  

NASA Astrophysics Data System (ADS)

The expression for the transient temperature during damped wave conduction and relaxation developed by Baumeister and Hamill by the method of Laplace transforms was further integrated. A Chebyshev polynomial approximation was used for the integrand with a modified Bessel composite function in space and time. A telescoping power series leads to a more useful expression for the transient temperature. By the method of relativistic transformation, the transient temperature during damped wave conduction and relaxation was developed. There are four regimes to the solution. These include: (i) a regime comprising a Bessel composite function in space and time, (ii) another regime comprising a modified Bessel composite function in space and time, (iii) the temperature solution at the wave front was also developed separately, and (iv) the fourth regime at a given location X in the medium is at times less than the inertial thermal lag time. In this regime, the temperature was found to be unchanged at the initial condition. The solution for the transient temperature from the method of relativistic transformation is compared side by side with the solution for the transient temperature from the method of Chebyshev economization. Both solutions are within 12% of each other. For conditions close to the wave front, the solution from the Chebyshev economization is expected to be close to the exact solution and was found to be within 2% of the solution from the method of relativistic transformation. Far from the wave front, i.e., close to the surface, the numerical error from the method of Chebyshev economization is expected to be significant and verified by a specific example. The solution for transient surface heat flux from the parabolic Fourier heart conduction model and the hyperbolic damped wave conduction and relaxation models are compared with each other. For ? > 1/2 the parabolic and hyperbolic solutions are within 10% of each other. The parabolic model has a blow-up as ? ? 0, and the hyperbolic model is devoid of singularities. The transient temperature from the Chebyshev economization is within an average of 25% of the error function solution for the parabolic Fourier heat conduction model. A penetration distance beyond which there is no effect of the step change in the boundary is predicted using the relativistic transformation model.

Sharma, Kal Renganathan

2009-10-01

390

Study on stoichiometric Ce:Mn:LiNbO3 crystal as a new nonvolatile holographic storage medium  

NASA Astrophysics Data System (ADS)

Stoichiometric Ce:Mn:LiNbO3 crystal was grown by the TSSG method for the first time. The congruent Ce:Mn:LiNbO3 (CCe:Mn:LiNbO3) crystal was grown by the Czochralski method. The lattice constant was tested. The lattice constant of the stoichiometric Ce:Mn:LiNbO3 (SCe:Mn:LiNbO3) crystal was less than that of CCe:Mn:LiNbO3 crystal. The absorption spectrum of the crystals was tested, the absorption edge of SCe:Mn:LiNbO3 crystal has violet shift comparing with that of CCe:Mn:LiNbO3 crystal. The exponential gain coefficient, the concentration of effective carrier, diffraction efficiency and response time were tested. Those properties of SCe:Mn:LiNbO3 crystal mentioned above have been improved. SCe:Mn:LiNbO3 crystal possesses the property of holographic storage for long.

Wang, Jun; Zhang, Zhonghua; Wang, Rui

2003-04-01

391

Annual collection and storage of solar energy for the heating of buildings. Report No. 3. Semiannual progress report, August 1977January 1978  

Microsoft Academic Search

A new system for year-round collection and storage of solar heated water for heating of buildings has been operated over the past year at the University of Virginia. The system is composed of an energy storage sub-system, which stores hot water in an underground pool, and of a solar collector sub-system which acts not only to collect solar energy throughout

J. T. Beard; F. A. Iachetta; L. U. Lilleleht; J. W. Dickey

1978-01-01

392

Annual collection and storage of solar energy for the heating of buildings. Report No. 2. Annual progress report, May 1976July 1977  

Microsoft Academic Search

A new system for year-round collection and storage of solar heated water for heating of buildings has been designed and constructed at the University of Virginia. The system is composed of an energy storage sub-system which stores hot water in an underground pool and of a solar collector sub-system which acts not only to collect solar energy throughout the year

J. T. Beard; F. A. Iachetta; L. U. Lilleleht; J. W. Dickey

1977-01-01

393

Annual Collection and Storage of Solar Energy for the Heating of Buildings, Report No. 3. Semi-Annual Progress Report, August 1977 - January 1978.  

ERIC Educational Resources Information Center

This report is part of a series from the Department of Energy on the use of solar energy in heating buildings. Described here is a new system for year around collection and storage of solar energy. This system has been operated at the University of Virginia for over a year. Composed of an underground hot water storage system and solar collection,

Beard, J. Taylor; And Others

394

Fatty acid\\/poly(methyl methacrylate) (PMMA) blends as form-stable phase change materials for latent heat thermal energy storage  

Microsoft Academic Search

Fatty acids such as stearic acid (SA), palmitic acid (PA), myristic acid (MA), and lauric acid (LA) are promising phase change materials (PCMs) for latent heat thermal energy storage (LHTES) applications, but high cost is the most drawback which limits the utility area of them in thermal energy storage. The use of fatty acids as form-stable PCM will increase their

Cemil Alkan; Ahmet Sari

2008-01-01

395

A Study on a Performance of Water-Spray-Type Ice Thermal Energy Storage Vessel with Vertical Heat Exchanger Plates  

NASA Astrophysics Data System (ADS)

A system with a water-embedded-trpe ice storage vessel is widely used because of its simple structure and compactness. However, the water-embedded-type ice storage vessel has a disadvantage, that is, the solidification rate is very small. The use of falling water film seems to be one of promising ways for solving this disadvantage. We have found in a previous study that the use of the falling water film is very effective, especially for high initial water temperatures. In the present study, we eexamined the performance of a faling-water-film-type ice thermal energy storage vessel with pratical size, having vertical heat exchanger plates. The ice making performance coefficient, ?, increases with time, and it becomes am aximum value of 2.5, after that, it decreases gradually. In order to make ice efficiently, it is necessary to set a flow rate of refrigerant properly and to adjust a difference between the evaporating temperature of refrigerant and the freezing point of water so that the refrigerant evaporates in the heat exchanger plates overall.

Yoshimura, Kenji; Sasaguchi, Kengo; Fukuda, Toshihito; Koyama, Shigeru

396

Lunox storage and transfer system  

NASA Technical Reports Server (NTRS)

This semester, efforts were concentrated on the design of the Lunox transfer line from the storage area to the launch site. Emphasis was placed on flow and heat transfer problems and their remedies by reducing the effect of radiation by selecting materials for storage tanks, transfer lines and insulation. The design for the storage tank was based on a medium sized Lunox production facility of 6,000 metric tons per year and the frequency of transportation of Lunox from lunar launch site to lower lunar orbit of four launches per month. The design included the selection of materials for cryogenic storage, insulation and radiation shielding. Lunox was pumped to the storage area near the launch site through a piping network designed for maximum mass flow rate with a minimum boil off. The entire network incorporated specially designed radiation shields made of material which was lightweight and low in secondary radiation.

1987-01-01

397

Effects of free convection on the oscillatory flow of a polar fluid through a porous medium in the presence of variable wall heat flux  

Microsoft Academic Search

The purpose of this work is to study a laminar two-dimensional free convective oscillatory flow of an incompressible polar\\u000a fluid through a saturated porous medium occupying a semi-infinite region of the space which is bounded by an infinite vertical\\u000a permeable plate in the presence of oscillating suction and variable wall heat flux. The governing equations are based on the\\u000a local

P. M. Patil

2008-01-01

398

Combined effect of viscous dissipation and Joule heating on MHD forced convection over a non-isothermal horizontal cylinder embedded in a fluid saturated porous medium  

Microsoft Academic Search

The effects of both first- and second-order resistance, due to the solid matrix of non-Darcy porous medium, Joule heating and viscous dissipation on forced convection flow from a horizontal circular cylinder under the action of a transverse magnetic field, has been studied. The case of variable wall temperature conditions is considered. The second-level local non-similarity method is used to convert

M. F. El-Amin

2003-01-01

399

Experiments on thermal characteristics of a natural circulation loop with latent heat energy storage under cyclic pulsed heat load  

NASA Astrophysics Data System (ADS)

An experimental investigation has been made of thermal characteristics of a rectangular, annular single-phase natural circulation loop with the inner tube filled with a solid-liquid phase change material (PCM) under cyclic pulsating heat load. A rectangular, annular loop of 150 cm in height and 75 cm in width was constructed with an annular gap of 0.6 cm, within which water was filled. The inner tube of the annular loop was filled with a PCM (n-Eicosene) or air. Under the cyclic pulsating heat load, temperature field within the water-filled annular loop with PCM- or air-filled inner tube was found to evolve into a steady periodic variation for the range of parameters considered. The water temperature and/or its fluctuating amplitude along the heated or cooled sections of the loop with the PCM-filled inner tube were found to be markedly lower than those measured in the loop with the air-filled inner tube under the identical conditions. On the other hand, along the insulated sections of the loop a somewhat minute difference in temporal variations of the water temperatures exists between the loops with PCM- and air-filled inner tube. In addition, at the outer wall along the cooled section, a time-periodic variation of temperature was detected in synchronizing with the pulsating heat load. Parametric effects of varying amplitude and time-period of the pulsating heat input, as well as of varying the inlet coolant temperature of the cooling jacket were investigated.

Tan, G. H.; Ho, C. J.

400

Models of the Intracluster Medium with Heating and Cooling: Explaining the Global and Structural X-Ray Properties of Clusters  

NASA Astrophysics Data System (ADS)

Nonradiative simulations that only include heating due to gravitational processes fail to match the observed mean X-ray properties of galaxy clusters. As a result, there has recently been increased interest in models in which either radiative cooling or entropy injection (and/or redistribution) plays a central role in mediating the thermal and spatial properties of the intracluster medium. Both sets of models can account for the mean global properties of clusters. Radiative cooling alone, however, results in fractions of cold/cooled baryons in excess of observationally established limits. On the other hand, the simplest entropy-injection models, by design, do not treat the ``cooling core'' structure present in many clusters and cannot account for declining entropy profiles toward cluster centers revealed by recent high-resolution X-ray observations. We consider models that marry radiative cooling with entropy injection, and confront model predictions for the global and structural properties of massive clusters with the latest X-ray data. The models successfully and simultaneously reproduce the observed luminosity-temperature (L-T) and luminosity-mass (L-M) relations, yield detailed entropy, surface brightness, and temperature profiles in excellent agreement with observations, and predict a cooled gas fraction that is consistent with observational constraints. More interestingly, the model provides a possible explanation for the significant intrinsic scatter present in the L-T and L-M relations. The model also offers a natural way of distinguishing between clusters classically identified as ``cooling flow'' clusters and the relaxed ``non-cooling flow'' clusters. The former correspond to systems that experienced only mild levels (<~300 keV cm2) of entropy injection, while the latter are identified as systems that had much higher entropy injection. The dividing line in entropy injection between the two categories corresponds roughly to the cooling threshold for massive clusters. This finding suggests that entropy injection may be an important, if not the primary, factor in determining the class a particular cluster will belong to. These results also suggest that the previously identified relationship between inferred cooling flow strength and the dispersion in the L-T relation is a manifestation of the distribution of cluster entropy-injection levels. This is borne out by the entropy profiles derived from Chandra and XMM-Newton. Finally, the model predicts a relationship between a cluster's central entropy and its core radius, the existence of which we confirm in the observational data.

McCarthy, Ian G.; Balogh, Michael L.; Babul, Arif; Poole, Gregory B.; Horner, Donald J.

2004-10-01

401

QUANTIFYING THE COMBINED EFFECTS OF THE HEATING TIME,1 THE TEMPERATURE AND THE RECOVERY MEDIUM PH ON THE2  

E-print Network

ON THE2 REGROWTH LAG TIME OF BACILLUS CEREUS SPORES AFTER A3 HEAT TREATMENT4 5 S. Gaillard(1) , I of this study was to quantify the lag time of re-growth of heated spores of14 Bacillus cereus as a function Keywords: Bacillus cereus, heat treatment, lag time, recovery.29 30 1. Introduction31 32 Bacillus cereus

Paris-Sud XI, Université de

402

Solar-powered saline sorbent-solution heat pump/storage system  

NASA Astrophysics Data System (ADS)

Coastal Energy Laboratory Chemical Heat Pump (CEL-CHEAP) is a redesigned open-cycle liquid desiccant air conditioner. Heat is discharged to shallow-well water by dehumidification-humidification for cooling and extracted by humidification-dehumidification for heating. Direct solar radiation concentrates the desiccant. For continuous operation, a small uninsulated tank stores concentrated solution. This chemical heat pump needs no mechanical compressor, condenser, vacuum system, or pressure system. The collector-regenerators are inexpensive. The refrigerant is water and the desiccant is calcium chloride. First cost and operating expenses are very low.

Robison, H.; Houston, S.

403

Heat recovery\\/thermal energy storage for energy conservation in food processing  

Microsoft Academic Search

Based on energy consumption data compiled for 1974, 59% of the total energy consumed in the US food processing industry was thermal energy. The energy-consuming processes which utilize this thermal energy reject significant quantities of waste heat, usually to the atmosphere or to the wastewater discharged from the plant. Design considerations for waste heat recovery systems in the food processing

R. S. Combes; W. B. Boykin

1981-01-01

404

The combined molten-salt thermal storage and sodium heat pipes for the ECA stirling engine  

Microsoft Academic Search

This paper describes the heat source used for the ECA Stirling engine. It has been developed within the energy source program for an underwater vehicle, and consists essentially of the following components: a molten-salt reservoir capable of delivering 420 kWh (t) by utilizing the heat change between the liquid and solid states of the salt, an electric charging system, a

T. Alleau; J. deLalleo; A. Bricard; J. Chabanne

1983-01-01

405

Environmental assessment for the relocation and storage of isotopic heat sources, Hanford Site, Richland, Washington  

SciTech Connect

As part of a bilateral agreement between the Federal Minister for Research and Technology of the Federal Republic of Germany (FRG) and the DOE, Pacific Northwest National Laboratory (PNNL) developed processes for the treatment and immobilization of high-level radioactive waste. One element of this bilateral agreement was the production of sealed isotopic heat sources. During the mid-1980s, 30 sealed isotopic heat sources were manufactured. The sources contain a total of approximately 8.3 million curies consisting predominantly of cesium-137 and strontium-90 with trace amounts of transuranic contamination. Currently, the sources are stored in A-Cell of the 324 Building. Intense radiation fields from the sources are causing the cell windows and equipment to deteriorate. Originally, it was not intended to store the isotopic heat sources for this length of time in A-cell. The 34 isotopic heat sources are classified as remote handled transuranic wastes. Thirty-one of the isotopic heat sources are sealed, and seals on the three remaining isotopic heat sources have not been verified. However, a decision has been made to place the remaining three isotopic heat sources in the CASTOR cask(s). The Washington State Department of Health (WDOH) has concurred that isotopic heat sources with verified seals or those placed into CASTOR cask(s) can be considered sealed (no potential to emit radioactive air emissions) and are exempt from WAC Chapter 246-247, Radiation Protection-Air Emissions.

NONE

1997-06-01

406

Energy Storage  

Microsoft Academic Search

The energy-conservation aspects and environmental benefits of large-scale energy-storage systems are reviewed and discussed. Uses of energy storage in power generation, transportation, and in commercial, residential, and industrial buildings are described. Methods and technology for storing mechanical, thermal, chemical, and electromagnetic energy are enumerated. These include pumped hydro, compressed air, flywheels, heat storage, batteries, hydrogen energy storage systems, and superconducting

F. R. Kalhammer; T. R. Schneider

1976-01-01

407

Heat transfer enhancement for thermal energy storage using metal foams embedded within phase change materials (PCMs)  

SciTech Connect

In this paper the experimental investigation on the solid/liquid phase change (melting and solidification) processes have been carried out. Paraffin wax RT58 is used as phase change material (PCM), in which metal foams are embedded to enhance the heat transfer. During the melting process, the test samples are electrically heated on the bottom surface with a constant heat flux. The PCM with metal foams has been heated from the solid state to the pure liquid phase. The temperature differences between the heated wall and PCM have been analysed to examine the effects of heat flux and metal foam structure (pore size and relative density). Compared to the results of the pure PCM sample, the effect of metal foam on solid/liquid phase change heat transfer is very significant, particularly at the solid zone of PCMs. When the PCM starts melting, natural convection can improve the heat transfer performance, thereby reducing the temperature difference between the wall and PCM. The addition of metal foam can increase the overall heat transfer rate by 3-10 times (depending on the metal foam structures and materials) during the melting process (two-phase zone) and the pure liquid zone. The tests for investigating the solidification process under different cooling conditions (e.g. natural convection and forced convection) have been carried out. The results show that the use of metal foams can make the sample solidified much faster than pure PCM samples, evidenced by the solidification time being reduced by more than half. In addition, a two-dimensional numerical analysis has been carried out for heat transfer enhancement in PCMs by using metal foams, and the prediction results agree reasonably well with the experimental data. (author)

Zhao, C.Y.; Lu, W.; Tian, Y. [School of Engineering, University of Warwick, CV4 7AL (United Kingdom)

2010-08-15

408

The effect of transpiration on coupled heat and mass transfer in mixed convection over a vertical plate embedded in a saturated porous medium  

SciTech Connect

Effect of transpiration velocity on the heat and mass transfer characteristics of mixed convection about a permeable vertical plate embedded in a saturated porous medium under the coupled effects of thermal and mass diffusion is numerically analyzed. The plate is maintained at a uniform temperature and species concentration with constant transpiration velocity. The transformed governing equations are solved by Keller box method. Numerical results for the local Nusselt number and local Sherwood number are presented. In general, it has been found for thermally assisted flow that the local surface heat and mass transfer rates increase owing to suction of fluid. This trend reversed for blowing of fluid. It is apparent that the Lewis number has a pronounced effect on the local Sherwood number than it does on the local Nusselt number. Increasing the Lewis number decreases (increases) the local heat (mass) transfer rate.

Yih, K.A. [Air Forces Inst. of Aeronautical Technology, Kaoshiuang (Taiwan, Province of China). Dept. of General Course] [Air Forces Inst. of Aeronautical Technology, Kaoshiuang (Taiwan, Province of China). Dept. of General Course

1997-03-01

409

Mixed convection flow about a solid sphere with a constant surface heat flux embedded in a porous medium filled with a nanofluid  

NASA Astrophysics Data System (ADS)

The steady laminar mixed convection boundary layer flow about a solid sphere embedded in a porous medium filled with a nanofluid, which is maintained at a constant surface heat flux, has been studied for both cases of a heated and cooled solid sphere. The resulting system of nonlinear partial differential equations is solved numerically using an implicit finite-difference scheme, namely the Keller box method. Three different types of nanoparticles are considered, namely Cu, Al2O3 and TiO2. Numerical solutions are obtained for the skin friction coefficient, the local wall temperature, the velocity and temperature profiles. The features of the flow and heat transfer characteristics for various values of the nanoparticle volume fraction and the mixed convection parameters are analyzed and discussed.

Tham, Leony; Nazar, Roslinda

2013-09-01

410

Mixed convection flow about a solid sphere with constant heat flux embedded in a porous medium filled by a nanofluid: Buongiorno-Darcy model  

NASA Astrophysics Data System (ADS)

The laminar mixed convection boundary layer flow about a solid sphere in a nanofluid, which is maintained at a constant surface heat flux, has been studied via the nanofluid Buongiorno model and porous medium Darcy model for both cases of a heated and cooled sphere. The resulting system of nonlinear partial differential equations is solved numerically using an implicit finite-difference scheme known as the Keller box method. The solutions for the flow and heat transfer characteristics are evaluated numerically and studied for various values of the governing parameters, namely the Brownian motion parameter, thermophoresis parameter and mixed convection parameter. It is found that the boundary layer separates from the sphere for some negative values of the mixed convection parameter (opposing flow), and increasing the mixed convection parameter delays the boundary layer separation and the separation can be completely suppressed for sufficiently large values of the mixed convection parameter.

Tham, Leony; Nazar, Roslinda; Pop, Ioan

2014-06-01

411

Non-Darcy Couette flow through a porous medium of magnetohydro-dynamic visco-elastic fluid with heat and mass transfer  

NASA Astrophysics Data System (ADS)

We analyze the steady magnetohydrodynamic flow of an incompressible electrically conducting visco-elastic fluid through a porous medium between two porous parallel plates under the influence of a transverse magnetic field. We obtain an exact solution for the Brinkman-Forchheimer extension of Darcy's momentum equation for flow. We solve the equations of motion with a perturbation technique under the assumption that the Forchheimer number Fs = b nu/u(0) is small. We analyze heat and mass transfer in porous media. We obtain the skin friction tau(w), the Nusselt number Nu, and the Sherwood number Sh. Our numerical results show the effects of the physical parameters of our problem on the fluid flow as well as on the heat and mass transfer, on the skin friction, and on the rates of heat and mass transfer.

Eldabe, N. T. M.; Sallam, S. N.

2005-12-01

412

Energy storage and heating measurements in flashlamp-pumped Cr:Nd:GSGG and Nd:YAG  

NASA Astrophysics Data System (ADS)

The authors have experimentally measured the energy stored and the heat generated in flashlamp-pumped Cr:Nd:GSGG for three Cr3+ concentrations in the range of 1-2 x 10to the 20th ions/cu cm. It has been found that the energy storage efficiency in these samples is 1.7 times greater than that of the Nd:YAG sample, and the normalized heating parameter chi, defined as the heat deposited per unit of stored energy, is 2.5 under the specified pumping conditions, with no evident dependence on the Cr3+ concentration. It has also been found that the measured chi value for the sample of Nd:YAG is 2.9 for the same pumping conditions. These observed chi values exceed expected values by factors of about 1.1 and 2 for the Cr:Nd:GSGG and Nd:YAG samples, respectively. The thermal focal length in the two materials was measured showing that the lensing is shorter in GSGG by a factor of 2.6 for the same available output power, or a factor of 4.5 for the same input pump power. The expected thermal lensing was determined using measured heat loads with no adjustable parameters, achieving satisfactory agreement with measured lensing values.

Sumida, David Shuji; Rockwell, David A.; Mangir, Metin S.

1988-06-01

413

Effect of Heat Treatment Process on Mechanical Properties and Microstructure of a 9% Ni Steel for Large LNG Storage Tanks  

NASA Astrophysics Data System (ADS)

In this paper, two different heat treatment processes of a 9% Ni steel for large liquefied natural gas storage tanks were performed in an industrial heating furnace. The former was a special heat treatment process consisting of quenching and intercritical quenching and tempering (Q-IQ-T). The latter was a heat treatment process only consisting of quenching and tempering. Mechanical properties were measured by tensile testing and charpy impact testing, and the microstructure was analyzed by optical microscopy, transmission electron microscopy, and x-ray diffraction. The results showed that outstanding mechanical properties were obtained from the Q-IQ-T process in comparison with the Q-T process, and a cryogenic toughness with charpy impact energy value of 201 J was achieved at 77 K. Microstructure analysis revealed that samples of the Q-IQ-T process had about 9.8% of austenite in needle-like martensite, while samples of the Q-T process only had about 0.9% of austenite retained in tempered martensite.

Zhang, J. M.; Li, H.; Yang, F.; Chi, Q.; Ji, L. K.; Feng, Y. R.

2013-12-01

414

HOTS; Underground heating oil tanks hold as many liabilities as other underground storage tanks  

Microsoft Academic Search

This paper reports on the liabilities associated with underground storage tanks (USTs) that are a growing concern. Tank owners worry that they will have or worse, will inherit financial or legal burdens resulting from leaking tanks. Indeed, it appropriate precautions are not taken, the consequences can be devastating. In 1984, after too many tank-related horror stories surfaced, Congress began to

Hayman

1989-01-01

415

Reversible Chemical Reactions for Energy Storage in a Large-Scale Heat Utility.  

National Technical Information Service (NTIS)

Described is a study of the feasibility of using either Ca(OH) sub 2 or CH sub 4 -CO sub 2 reaction systems for long-duration storage in a central receiver, solar energy facility. The system is required to generate 262 MW/sub t/ (895 x 10 exp 6 Btu/h) as ...

R. G. B. P. Nix, R. E. West

1982-01-01

416

Reversible chemical reactions for energy storage in a large-scale heat utility  

NASA Astrophysics Data System (ADS)

This paper describes a study of the feasibility of using either Ca(OH)2 or CH4-CO2 reaction systems for long-duration storage in a central receiver, solar energy facility. The system is required to operate 262 MW(t) (8.95 x 10 to the 8th Btu/h) as 4.14-MPa (600-psig), 400 C (750 F) superheated steam, with usage split evenly among 10 users clustered in an industrial park. Results indicate that use of a solar thermal system with long-duration storage of either thermomechanical or direct thermal energy (molten draw salt) is probably not justified when compared to the use of coal-fired boilers for steam generation. However, solar thermal systems with either thermochemical or direct thermal energy storage may be competitive with oil- or natural gas-fired boilers if the cost of the solar energy supplied to the storage system is sufficiently low and the costs of oil and natural gas have escalated to a sufficiently high level.

Nix, R. G.; Bergeron, P. W.; West, R. E.

417

Migration of bisphenol A from can coatingseffects of damage, storage conditions and heating  

Microsoft Academic Search

Bisphenol A (BPA) is an important monomer used in the manufacture of epoxy resins for internal food can linings. Experiments were conducted to investigate the effects of different storage conditions and can damage on the migration of BPA to foods. These experiments were conducted in a systematic fashion by filling empty epoxyphenolic coated cans with four foods: soup, minced beef,

A. Goodson; H. Robin; W. Summerfield; I. Cooper

2004-01-01

418

Heat and mass transfer in hydromagnetic flow of the non-Newtonian fluid with heat source over an accelerating surface through a porous medium  

Microsoft Academic Search

An analysis is made to determine the heat and mass transfer occurring in the hydromagnetic flow of the non-Newtonian fluid on a linearly accelerating surface with temperature-dependent heat source subject to suction or blowing. The results are expressed in terms of Kummer's function in the case of a surface with prescribed wall temperature. Numerical calculations have been carried out for

Nabil T. M. Eldabe; Mona A. A. Mohamed

2002-01-01

419

Reversible chemical reactions for energy storage in a large-scale heat utility  

Microsoft Academic Search

This paper describes a study of the feasibility of using either Ca(OH)2 or CH4-CO2 reaction systems for long-duration storage in a central receiver, solar energy facility. The system is required to operate 262 MW(t) (8.95 x 10 to the 8th Btu\\/h) as 4.14-MPa (600-psig), 400 C (750 F) superheated steam, with usage split evenly among 10 users clustered in an

R. G. Nix; P. W. R. G. Bergeron; R. E. West

1982-01-01

420

An investigation into the thermal properties of selected sensible and latent heat storage materials  

E-print Network

University; Chairman of Advisory Committee: Dr. Peter E. Jenkins An experimental investigation was conducted into the thermal properties of cement mortar rods, rocks, and cans of calcium chloride. A test apparatus was designed and con- structed... Mortar, Low Flow/ Low Temperature Figure 3. 5 Cement Mortar, Low Flow/Medium Temperature 35 Figure 3. 6 Cement Mortar, Low Flow/High Temperature Figure 3. 7 Cement Mortar, High Flow/Low Temperature Figure 3. 8 Cement Mortar, High Flow...

Wood, Stanley Clayton

2012-06-07

421

Effect of heat processing and storage time on migration of bisphenol A (BPA) and bisphenol A-diglycidyl ether (BADGE) to aqueous food simulant from Mexican can coatings.  

PubMed

Effects of heat processing and storage time (up to 70 days) on migration of bisphenol A (BPA) and bisphenol A-diglycidyl ether (BADGE) from can coatings into an aqueous food simulant were determined. Distilled water was canned in two types of Mexican cans: for tuna and for jalapeo peppers. Results showed that there is an effect of heat treatment on migration of both compounds. Storage time did not show any effect in BPA migration from tuna cans. There was an effect of storage time on BPA migration from jalapeo pepper cans. Results for BADGE migration were affected by its susceptibility to hydrolyze in aqueous simulants. BADGE concentration decreased, or was not detected, during storage in both types of cans. Migration levels for BPA and BADGE were within 0.6-83.4 and <0.25-4.3 microg/kg, respectively. Both were below European and Mercosur legislation limits. Other migrating compounds were detected, although no identification was performed. PMID:11513645

Munguia-Lopez, E M; Soto-Valdez, H

2001-08-01

422

Nonsteady Flow of a Power-Law Fluid in a Porous Medium between Parallel Plates with Heat Transfer, Suction, and Injection  

NASA Astrophysics Data System (ADS)

The time-varying flow of a viscous incompressible non-Newtonian power-law fluid through a porous medium between two parallel horizontal porous plates under the action of a constant pressure gradient with consideration for heat transfer is studied. Uniform suction and injection through the surfaces of the plates take place where the two plates are kept at different, but constant temperatures, and the Joule and viscous dissipation terms are considered in the energy equation. Numerical solutions for the governing nonlinear momentum and energy equations are obtained using finite differences. The effect of the medium porosity, the parameter describing the non-Newtonian behavior, and the velocity of suction and injection on both the velocity and temperature distributions, as well as on the dissipation terms, is investigated.

Attia, Hazem Ali; Abdeen, Mostafa A. M.; Abdin, Alaa El-Din

2013-05-01

423

SERI solar energy storage program  

Microsoft Academic Search

Thermal energy storage technologies are identified for specific solar thermal applications. The capabilities and limitations of direct-contact thermal storage and thermochemical energy storage and transport are examined. Storage of energy from active solar thermal systems for industrial process heat and the heating of buildings is analyzed and seasonal energy storage is covered. The coordination of numerous thermal energy storage research

F. Baylin; R. J. Copeland; A. Kotch; T. Kriz; W. Luft; R. G. Nix; J. O. Wright

1982-01-01

424

Economic analysis of community solar heating systems that use annual cycle thermal energy storage  

NASA Astrophysics Data System (ADS)

Systems were sized for three housing configurations: single unit dwellings, 10 unit, and 200 unit apartment complexes in 50, 200, 400, and 1000 unit communities in 10 geographic locations in the United States. Thermal energy is stored in large, constructed, underground tanks. Costs were assigned to each component of every system in order to allow calculation of total costs. Results are presented as normalized system costs per unit of heat delivered per building unit. These methods allow: identification of the relative importance of each system component in the overall cost; and identification of the key variables that determine the optimum sizing of a district solar heating system.

Baylin, F.; Monte, R.; Sillman, S.; Hooper, F. C.; McClenahan, J. D.

1981-02-01

425

Effect of Heat Input on Microstructural Changes and Corrosion Behavior of Commercially Pure Titanium Welds in Nitric Acid Medium  

NASA Astrophysics Data System (ADS)

Commercially pure titanium (Ti) has been selected for the fabrication of dissolver for the proposed fast reactor fuel reprocessing plant at Kalpakkam, India. In the present investigation, microstructural changes and corrosion behavior of tungsten inert gas (TIG) welds of Ti grade-1 and grade-2 with different heat inputs were carried out. A wider heat affected zone was observed with higher heat inputs and coarse grains were observed from base metal toward the weld zone with increasing heat input. Fine and more equiaxed prior ? grains were observed at lower heat input and the grain size increased toward fusion zone. The results indicated that Ti grade-1 and grade-2 with different heat inputs and different microstructures were insensitive to corrosion in liquid, vapor, and condensate phases of 11.5 M nitric acid tested up to 240 h. The corrosion rate in boiling liquid phase (0.60-0.76 mm/year) was higher than that in vapor (0.012-0.039 mm/year) and condensate phases (0.04-0.12 mm/year) of nitric acid for Ti grade-1 and grade-2, as well as for base metal for all heat inputs. Potentiodynamic polarization experiment carried out at room temperature indicated higher current densities and better passivation in 11.5 M nitric acid. SEM examination of Ti grade-1 welds for all heat inputs exposed to liquid phase after 240 h showed corrosion attack on the surface, exposing Widmanstatten microstructure containing acicular alpha. The continuous dissolution of the liquid-exposed samples was attributed to the heterogeneous microstructure and non-protective passive film formation.

Ravi Shankar, A.; Gopalakrishnan, G.; Balusamy, V.; Kamachi Mudali, U.

2009-11-01

426

Cumulative effects of heat exposure and storage conditions of Oxytocin-in-Uniject in rural Ghana: implications for scale up  

PubMed Central

ABSTRACT Objective: Postpartum hemorrhage can be reduced substantially in home deliveries attended by community-based workers by using Oxytocin-in-Uniject (OIU) devices affixed with temperature-time indicators. We characterized the distribution of time to discard of these devices when stored under normal field conditions in Ghana. Methods: Two drug storage simulation studies were conducted in rural Ghana in 2011 and 2012. Devices were transported under refrigeration from manufacture (Argentina) to storage at the study site. Twenty-three field workers each stored at home (unrefrigerated) 25 OIU devices and monitored them daily to record: (1) time to transition from usable to unusable, and (2) continuous digital ambient temperature to determine heat exposure over the simulation period. Time to discard was estimated and compared with mean kinetic temperature exposure of the devices during the shipment and storage phases and with characteristics of the storage locations using Weibull regression models. We used the time to discard distributions in a Monte Carlo simulation to estimate wastage rates in a hypothetical program setting. Results: Time for shipment and transfer to long-term refrigerated storage and mean kinetic temperature during the shipment phase was 8.6 days/10.3C and 13.4 days/12.1C, for the first and second simulation studies, respectively. Median (range) time to discard when stored under field conditions (unrefrigerated) was 43 (6 to 59) days and 33 (14 to 50) days, respectively. Mean time to discard was 10.0 days shorter in the second simulation, during which mean kinetic temperature exposure was 3.9C higher. Simulating a monthly distribution system and assuming typical usage, predicted wastage of product was less than 10%. Conclusion: The time to discard of devices was highly sensitive to small changes in temperature exposure. Under field conditions typical in rural Ghana, OIU packages will have a half-life of approximately 30 to 40 days based on the temperature monitor used during the study. Program managers will need to carefully consider variations in both ambient temperature and rate of use to allocate the appropriate supply level that will maximize coverage and minimize stock loss.

Mullany, Luke C; Newton, Sam; Afari-Asiedu, Samuel; Adiibokah, Edward; Agyemang, Charlotte T; Cofie, Patience; Brooke, Steve; Owusu-Agyei, Seth; Stanton, Cynthia K

2014-01-01

427

Demonstration ice storage with waste-heat-recovery project. Final report  

Microsoft Academic Search

The goals of the reported project were to: construct a compact, package-type cooling system; test ice storing capacity in relation to time, weight, and total energy consumption; design and install an ice bank system with heat recovery capacity in a residence; and meter and monitor the system in operation and compare with other systems in similar residences for energy consumption,

Shipper

1980-01-01

428

Quantification of subsurface heat storage in a GCM simulation Andrew H. MacDougall,1  

E-print Network

climate change and for assessing its impact on society [Intergovernmental Panel on Climate Change (IPCC 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

Beltrami, Hugo

429

Effect of hydrophilic admixtures on moisture and heat transport and storage parameters of mineral wool  

Microsoft Academic Search

Water vapor diffusion coefficient, liquid moisture diffusivity, adsorption isotherm, water retention curve, thermal conductivity and specific heat capacity of two new hydrophilic mineral wool materials are determined in the paper. For the sake of comparison, the same parameters are also measured for two hydrophobic mineral wool materials and two mineral wool materials without any specific admixtures. It is shown that

Milena Ji?i?kov; Robert ?ern

2006-01-01

430

Polymer alloys with balanced heat storage capacity and engineering attributes and applications thereof  

Microsoft Academic Search

A thermoplastic polymer of relatively low melt temperature is blended with at least one of thermosets, elastomers, and thermoplastics of relatively high melt temperature in order to produce a polymer blend which absorbs relatively high quantities of latent heat without melting or major loss of physical and mechanical characteristics as temperature is raised above the melting temperature of the low-melt-temperature

Soroushian; Parviz

2002-01-01

431

Microbial activity in argillite waste storage cells for the deep geological disposal of French bituminous medium activity long lived nuclear waste: Impact on redox reaction kinetics and potential  

NASA Astrophysics Data System (ADS)

Micro-organisms are ubiquitous and display remarkable capabilities to adapt and survive in the most extreme environmental conditions. It has been recognized that microorganisms can survive in nuclear waste disposal facilities if the required major (P, N, K) and trace elements, a carbon and energy source as well as water are present. The space constraint is of particular interest as it has been shown that bacteria do not prosper in compacted clay. An evaluation of the different types of French medium and high level waste, in a clay-rich host rock storage environment at a depth between 500 and 600 m, has shown that the bituminous waste is the most likely candidate to accommodate significant microbial activity. The waste consists of a mixture of bitumen (source of bio-available organic matter and H2 as a consequence of its degradation and radiolysis) and nitrates and sulphates kept in a stainless steel container. The assumption, that microbes only have an impact on reaction kinetics needs to be reassessed in the case where nitrates and sulphates are present since both are known not to react at low temperatures without bacterial catalysis. The additional impact of both oxy-anions and their reduced species on redox conditions, radionuclide speciation and mobility gives this evaluation their particular relevance. Storage architecture proposes four primary waste containers positioned into armoured cement over packs and placed with others into the waste storage cell itself composed of a cement mantle enforcing the argillite host rock, the latter being characterized by an excavation damaged zone constricted both in space and in time and a pristine part of 60 m thickness. Bacterial activity within the waste and within the pristine argillite is disregarded because of the low water activity (< 0.7) and the lack of space, respectively. The most probable zones of microbial activity, those likely to develop sustainable biofilms are within the interface zones. A major restriction for the initial development of microbial colonies is the high pH controlled by the cement solution. Archea are able to survive at high pH, when hydrogen gas is available as an energy sources; they are therefore likely candidates for an initial biofilm formation. It can not be excluded that other micro-organisms such as fungi may develop as well in such conditions. It also needs to be evaluated how conditions change with time and how this affects microbial ecology. The following is known about the impact of microbes on the waste cell biogeochemistry: enhancement of redox reaction kinetics (particularly involving nitrates, sulphate, selenate, pertechnetate, organic matter and H2), thus a faster move towards reducing conditions, important to guarantee the low mobility of critical RN, increased retardation of mobile RN in biofilms (i.e. adsorption on microbial cell surfaces and products of possible biomineralization); complexation by embedded extracellular polymeric substances, secretion of organic substances (i.e siderophores) known to complex RN and to enhance their mobility, biodegradation of dissolved organic substances, such as those released form the waste (organic acids) or generated by microbes, production of CO2 or other gases that may affect cement integrity. Quantification of microbial activity has been implemented into biogeochemical models but the important parameters describing their evolution and metabolism in the real system (ecology, mass, energy sources, metabolites) need to be obtained via specific empirical studies. Such studies require a particular trans-disciplinary approach that brings together the competence of chemical and environmental engineers, microbiologists and system modellers.

Albrecht, A.; Leone, L.; Charlet, L.

2009-04-01

432

Comment on Magnetohydrodynamic non-Darcy mixed convection heat transfer from a vertical heated plate embedded in a porous medium with variable porosity, by Dulal Pal  

E-print Network

In the above paper the author treats the boundary layer flow along a vertical flat plate, immersed in a Darcy Brinkman Forchheimer porous medium. The porosity and the permeability of the porous medium are variable across the boundary layer. In addition a magnetic field with constant strength is applied normal to the plate. The fluid temperature at the plate is constant and different from that of the ambient fluid. This temperature difference creates a buoyancy force and the flow is characterized as mixed convection. The partial differential equations of the boundary layer flow are transformed into ordinary differential equations and subsequently are solved with the Runge-Kutta Fehlberg method. The results are presented in two tables and 11 figures.

Pantokratoras, Asterios

2014-01-01

433

Effect of nanoparticles on heat capacity of nanofluids based on molten salts as PCM for thermal energy storage  

PubMed Central

In this study, different nanofluids with phase change behavior were developed by mixing a molten salt base fluid (selected as phase change material) with nanoparticles using the direct-synthesis method. The thermal properties of the nanofluids obtained were investigated. These nanofluids can be used in concentrating solar plants with a reduction of storage material if an improvement in the specific heat is achieved. The base salt mixture was a NaNO3-KNO3 (60:40 ratio) binary salt. The nanoparticles used were silica (SiO2), alumina (Al2O3), titania (TiO2), and a mix of silica-alumina (SiO2-Al2O3). Three weight fractions were evaluated: 0.5, 1.0, and 1.5 wt.%. Each nanofluid was prepared in water solution, sonicated, and evaporated. Measurements on thermophysical properties were performed by differential scanning calorimetry analysis and the dispersion of the nanoparticles was analyzed by scanning electron microscopy (SEM). The results obtained show that the addition of 1.0 wt.% of nanoparticles to the base salt increases the specific heat of 15% to 57% in the solid phase and of 1% to 22% in the liquid phase. In particular, this research shows that the addition of silica-alumina nanoparticles has a significant potential for enhancing the thermal storage characteristics of the NaNO3-KNO3 binary salt. These results deviated from the predictions of the theoretical model used. SEM suggests a greater interaction between these nanoparticles and the salt. PMID:24168168

2013-01-01

434

Effect of nanoparticles on heat capacity of nanofluids based on molten salts as PCM for thermal energy storage.  

PubMed

In this study, different nanofluids with phase change behavior were developed by mixing a molten salt base fluid (selected as phase change material) with nanoparticles using the direct-synthesis method. The thermal properties of the nanofluids obtained were investigated. These nanofluids can be used in concentrating solar plants with a reduction of storage material if an improvement in the specific heat is achieved. The base salt mixture was a NaNO3-KNO3 (60:40 ratio) binary salt. The nanoparticles used were silica (SiO2), alumina (Al2O3), titania (TiO2), and a mix of silica-alumina (SiO2-Al2O3). Three weight fractions were evaluated: 0.5, 1.0, and 1.5 wt.%. Each nanofluid was prepared in water solution, sonicated, and evaporated. Measurements on thermophysical properties were performed by differential scanning calorimetry analysis and the dispersion of the nanoparticles was analyzed by scanning electron microscopy (SEM). The results obtained show that the addition of 1.0 wt.% of nanoparticles to the base salt increases the specific heat of 15% to 57% in the solid phase and of 1% to 22% in the liquid phase. In particular, this research shows that the addition of silica-alumina nanoparticles has a significant potential for enhancing the thermal storage characteristics of the NaNO3-KNO3 binary salt. These results deviated from the predictions of the theoretical model used. SEM suggests a greater interaction between these nanoparticles and the salt. PMID:24168168

Chieruzzi, Manila; Cerritelli, Gian F; Miliozzi, Adio; Kenny, Jos M

2013-01-01

435

A novel heat transfer model and its application to information storage systems  

NASA Astrophysics Data System (ADS)

Lattice Boltzmann method (LBM) based on Boltzmann transport equation is developed to simulate the nanoscale heat transport in solids. The LBM can simulate both the metals and semiconductors by properly incorporating the energy carriers. We found that boundary scattering of phonons results in an anisotropic thermal transport in nanoscale solids. The electron-phonon coupling is introduced to accurately describe the thermal behavior of nanoscale confined solids. Our numerical tool will be suitable for simulating complex multiscale systems involving multiple energy carriers with different length and time scales, and is useful in magnetic recording technology when the thermal response plays a crucial role such as for reliability of the head-disk interface and the heat assisted magnetic recording systems.

Ghai, Sartaj S.; Kim, Woo Tae; Escobar, Rodrigo A.; Amon, Cristina H.; Jhon, Myung S.

2005-05-01

436

On the influence of wall properties in the MHD peristaltic transport with heat transfer and porous medium  

NASA Astrophysics Data System (ADS)

The effect of elasticity of the flexible walls on the MHD peristaltic flow of a Newtonian fluid in a two-dimensional porous channel with heat transfer has been studied under the assumptions of long-wavelength and low-Reynolds number. The analytical solution has been obtained for the stream function, temperature and heat transfer coefficient. The effect of various emerging parameters on the flow characteristics are shown and discussed with the help of graphs. The numerical results show that the trapped bolus increases in size and more trapped bolus appears with increasing permeability parameter, elastic tension and mass characterizing parameters but decreases for large values of Hartmann number.

Kothandapani, M.; Srinivas, S.

2008-06-01

437

Solid state phase change materials for thermal energy storage in passive solar heated buildings  

NASA Astrophysics Data System (ADS)

A set of solid state phase change materials was evaluated for possible use in passive solar thermal energy storage systems. The most promising materials are organic solid solutions of pentaerythritol, pentaglycerine and neopentyl glycol. Solid solution mixtures of these compounds can be tailored so that they exhibit solid-to-solid phase transformations at any desired temperature within the range from less than 25 deg to 188 deg. Thermophysical properties such as thermal conductivity, density and volumetric expansion were measured. Computer simulations were used to predict the performance of various Trombe wall designs incorporating solid state phase change materials. Optimum performance was found to be sensitive to the choice of phase change temperatures and to the thermal conductivity of the phase change material. A molecular mechanism of the solid state phase transition is proposed and supported by infrared spectroscopic evidence.

Benson, D. K.; Christensen, C.

1983-11-01

438

Structural assessment of a Space Station solar dynamic heat receiver thermal energy storage canister  

NASA Technical Reports Server (NTRS)

This paper assesses the structural performance of a Space Station thermal energy storage (TES) canister subject to orbital solar flux variation and engine cold start-up operating conditions. The impact of working fluid temperature and salt-void distribution on the canister structure are assessed. Both analytical and experimental studies were conducted to determine the temperature distribution of the canister. Subsequent finite-element structural analyses of the canister were performed using both analytically and experimentally obtained temperatures. The Arrhenius creep law was incorporated into the procedure, using secondary creep data for the canister material, Haynes-188 alloy. The predicted cyclic creep strain accumulations at the hot spot were used to assess the structural performance of the canister. In addition, the structural performance of the canister based on the analytically-determined temperature was compared with that based on the experimentally-measured temperature data.

Tong, M. T.; Kerslake, T. W.; Thompson, R. L.

1988-01-01

439

Structural assessment of a space station solar dynamic heat receiver thermal energy storage canister  

NASA Technical Reports Server (NTRS)

The structural performance of a space station thermal energy storage (TES) canister subject to orbital solar flux variation and engine cold start up operating conditions was assessed. The impact of working fluid temperature and salt-void distribution on the canister structure are assessed. Both analytical and experimental studies were conducted to determine the temperature distribution of the canister. Subsequent finite element structural analyses of the canister were performed using both analytically and experimentally obtained temperatures. The Arrhenius creep law was incorporated into the procedure, using secondary creep data for the canister material, Haynes 188 alloy. The predicted cyclic creep strain accumulations at the hot spot were used to assess the structural performance of the canister. In addition, the structural performance of the canister based on the analytically determined temperature was compared with that based on the experimentally measured temperature data.

Thompson, R. L.; Kerslake, T. W.; Tong, M. T.

1988-01-01

440

Modeling High-Temperature Direct-Contact Heat Exchange in an Irrigated Packed Bed.  

National Technical Information Service (NTIS)

This report presents an analytical model of direct-contact heat exchange (DCHX) in an irrigated packed bed at high temperatures. The specific application is heat exchange between molten salt and air where the molten salt is a sensible heat storage medium ...

M. S. Bohn

1987-01-01

441

Heat transfer analysis on the MHD flow of a second grade fluid in a channel with porous medium  

Microsoft Academic Search

In this paper, the heat transfer analysis is investigated for magnetohydrodynamic (MHD) flow in a porous channel. The second grade fluid fills the porous space inside the channel. The governing non-linear problem is solved analytically. Homotopy analysis method (HAM) is employed to obtain the expressions for velocity and temperature fields. Convergence of the obtained solutions is properly analyzed. Graphs are

T. Hayat; Z. Abbas

2008-01-01

442

Phase Change Characteristics of a Nanoemulsion as a Latent Heat Storage Material  

NASA Astrophysics Data System (ADS)

The primary objective of this study was to investigate the fundamental phase change characteristics of a nanoemulsion using differential scanning calorimetry (DSC). Tetradecane, which has a slightly higher melting point than water, was utilized as the phase change material for the nanoemulsion. The melting point of the nanoemulsion, the melting peak temperature, and latent heat were examined in detail. Regarding the fundamental phase change characteristics of the nanoemulsion, it was found that its phase change characteristics were strongly affected by the temperature-scanning rate of the DSC. Moreover, it was confirmed that the phase change behavior does not change with repeated solidification and melting.

Fumoto, Koji; Sato, Noriaki; Kawaji, Masahiro; Kawanami, Tsuyoshi; Inamura, Takao

2014-10-01

443

Extended development of a sodium hydroxide thermal energy storage module  

NASA Technical Reports Server (NTRS)

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 a dual heat exchanger concept within the storage module is presented. A computer model and a reference design for the dual system (storage working fluid/power cycle working fluid) were completed. The dual system is estimated to have a capital cost of approximately one half that of the single heat exchanger concept.

Rice, R. E.; Rowny, P. E.; Cohen, B. M.

1980-01-01

444

Heat balance and cumulative heat storage during exercise performed in the heat in physically active younger and middle-aged men.  

PubMed

On separate days, eight physically active younger (22 +/- 2 years) and eight highly trained middle-aged (45 +/- 4 years) men matched for physical fitness and body composition performed 90 min of semi-recumbent cycling at a constant rate of heat production (290 W) followed by 60 min of seated recovery in either a temperate (T, 30 degrees C), warm (W, 35 degrees C) or hot (H, 40 degrees C) ambient condition. Rectal temperature (T (re)) was measured continuously, while the rate of whole-body heat loss (H (L)), as well as changes in body heat content (H (b)) was measured simultaneously using direct whole-body and indirect calorimetry. No difference in H (L) was observed between age groups for all ambient conditions. Accordingly, the average H (b) during the 90-min exercise was similar for the younger (+193 +/- 52, 212 +/- 82 and +211 +/- 44 kJ for T, W and H, respectively) and middle-aged men (+192 +/- 119, +225 +/- 76 and +217 +/- 130 kJ for T, W and H, respectively). This was paralleled by a similar increase in T (re) of 0.40 +/- 0.20, 0.36 +/- 0.14 and 0.34 +/- 0.23 degrees C for T, W and H, respectively in the younger men and 0.37 +/- 0.23, 0.32 +/- 0.19 and 0.28 +/- 0.14 degrees C for T, W and H, respectively in the middle-aged men. After 60 min of recovery, H (b) was similar for the younger and the middle-aged men, respectively (-45 +/- 52 and -38 +/- 31 kJ for T; -57 +/- 78 and -40 +/- 25 kJ for W; and -32 +/- 71 and 11 +/- 96 kJ for H). End recovery T (re) remained elevated to similar levels in both the younger and middle-aged men, respectively, for each of the ambient conditions (0.24 +/- 019 and 0.18 +/- 0.18 degrees C for T; 0.25 +/- 0.11 and 0.24 +/- 0.14 degrees C for W and 0.33 +/- 0.21 and 0.33 +/- 0.13 degrees C for H). We conclude that highly trained middle-aged men demonstrate a similar capacity for heat dissipation when compared with physically active younger men. PMID:19885672

Kenny, Glen P; Gagnon, Daniel; Dorman, Lucy E; Hardcastle, Stephen G; Jay, Ollie

2010-05-01

445

Turbulent Heat Transfer In A Molten Salt Receiver Tube With Uniform and Nonuniform Heat Flux Around The Circumference  

Microsoft Academic Search

Solar Power Tower(SPT) system with molten salt technology represents the most cost effective and leading candidate technology for electricity generation for stand-alone Solar Power Plants. For it can take advantages from its high concentration, allowing to work at high temperature and can incorporate the working fluid for heat transfer and heat storage in a same medium, and therefore with a

Chun Chang; Zhifeng Wang; Yong-Heack Kang; Jong-Kyu Kim; Xin L; Fengwu Bai

446

Effect of sporulation medium on wet-heat resistance and structure of Alicyclobacillus acidoterrestris DSM 3922-type strain spores and modeling of the inactivation kinetics in apple juice.  

PubMed

Alicyclobacillus acidoterrestris is a spoilage bacterium in fruit juices leading to high economic losses. The present study evaluated the effect of sporulation medium on the thermal inactivation kinetics of A. acidoterrestris DSM 3922 spores in apple juice (pH3.820.01; 11.30.1 Brix). Bacillus acidocaldarius agar (BAA), Bacillus acidoterrestris agar (BATA), malt extract agar (MEA), potato dextrose agar (PDA) and B. acidoterrestris broth (BATB) were used for sporulation. Inactivation kinetic parameters at 85, 87.5 and 90C were obtained using the log-linear model. The decimal reduction times at 85C (D85C) were 41.7, 57.6, 76.8, 76.8 and 67.2min; D87.5C-values were 22.4, 26.7, 32.9, 31.5, and 32.9min; and D90C-values were 11.6, 9.9, 14.7, 11.9 and 14.1min for spores produced on PDA, MEA, BATA, BAA and BATB, respectively. The estimated z-values were 9.05, 6.60, 6.96, 6.15, and 7.46, respectively. The present study suggests that the sporulation medium affects the wet-heat resistance of A. acidoterrestris DSM 3922 spores. Also, the dipicolinic acid content (DPA) was found highest in heat resistant spores formed on mineral containing media. After wet-heat treatment, loss of internal volume due to the release of DPA from spore core was observed by scanning electron microscopy. Since, there is no standardized media for the sporulation of A. acidoterrestris, the results obtained from this study might be useful to determine and compare the thermal resistance characteristics of A. acidoterrestris spores in fruit juices. PMID:25129530

Molva, Celenk; Baysal, Ayse Handan

2014-10-17

447

Using survival analysis to investigate the effect of UV-C and heat treatment on storage rot of strawberry and sweet cherry  

Microsoft Academic Search

Ultraviolet light and heat treatment are proposed as alternative techniques for the use of chemicals to reduce the development of the spoilage fungi Botrytis cinerea and Monilinia fructigena on strawberry and sweet cherry, respectively, during storage. In order to investigate the effect of both physical techniques on microbial inactivation and on fruit quality, inoculated berries were subjected to different temperatures

D Marquenie; C. W Michiels; A. H Geeraerd; A Schenk; C Soontjens; J. F Van Impe

2002-01-01

448

Transient Mixed Convection In Channels Partially Heated Filled With A Porous Medium In Non-Local Thermal Equilibrium  

NASA Astrophysics Data System (ADS)

In this paper, reference is made to transient mixed convection in air in a vertical channel with porous media and the two principal flat plates at uniform temperature with adiabatic extensions downstream. The numerical analysis is carried out in transient laminar, two dimensional and in nonlocal thermal equilibrium. The physical domain consists of two parallel plates which form a channel and the adiabatic extensions downstream to the heated walls. Both plates are heated at uniform temperature. The fluid between the two plates is air. The study is carried out employing Brinkman-Forchheimer-extended Darcy model and two energy equations. The flow in the channel is assumed to be two-dimensional, laminar, incompressible. Results in terms of local Nusselt number profiles as a function of mass flow rate, adiabatic extensions length, wall temperatures and channel spacing are presented. Average Nusselt numbers are presented for different values of characteristic parameters.

Buonomo, Bernardo; Manca, Oronzio; Mesolella, Paolo; Nardini, Sergio

2010-05-01

449

Use of Cooling Thermal Storage as a Heat Sink for Steam Power Plant  

NASA Astrophysics Data System (ADS)

In the present paper, a system is proposed for improving the performance of steam power plant with air-cooled condenser during peak loads. In this system, the power plant comprises two steam turbines, and the air-cooled condenser is replaced by two condensers. The first one is air-cooled (dry) and used for condensing the exhaust steam of the first turbine, while the second is water-cooled and serves to condense the steam outlet of the second turbine. The warm cooling water exiting the wet condenser is pumped to a cooling storage container, where it is cooled and re-circulated to the wet condenser. Cooling is produced by a refrigeration machine driven by the extra electric power generated by the two turbines during the time of the off-peak-loads (low electricity rates). Simple energy analyses have been developed to predict the energy characteristics of this system. The results of this paper showed that the proposed system leads to improving the plant power output at peak-loads. About 6, 16, 24 and 33% increase in generated plant power can be achieved at peak-loads (high electricity rates) when the ambient temperature is 20, 30, 40 and 50C respectively, and the whole steam exiting both turbines is cooled in a wet condenser to a design temperature of 20C. The results showed also that choice of the capacity of each turbine is essentially affected by the quality of the refrigeration machine and ambient temperature.

Hegazy, Ahmed Sabry

450

Electrolysed reduced water decreases reactive oxygen species-induced oxidative damage to skeletal muscle and improves performance in broiler chickens exposed to medium-term chronic heat stress.  

PubMed

1. The present study was designed to achieve a reduction of reactive oxygen species (ROS)-induced oxidative damage to skeletal muscle and to improve the performance of broiler chickens exposed to chronic heat stress. 2. Chickens were given a control diet with normal drinking water, or diets supplemented with cashew nut shell liquid (CNSL) or grape seed extract (GSE), or a control diet with electrolysed reduced water (ERW) for 19 d after hatch. Thereafter, chickens were exposed to a temperature of either 34C continuously for a period of 5 d, or maintained at 24C, on the same diets. 3. The control broilers exposed to 34C showed decreased weight gain and feed consumption and slightly increased ROS production and malondialdehyde (MDA) concentrations in skeletal muscle. The chickens exposed to 34C and supplemented with ERW showed significantly improved growth performance and lower ROS production and MDA contents in tissues than control broilers exposed to 34C. Following heat exposure, CNSL chickens performed better with respect to weight gain and feed consumption, but still showed elevated ROS production and skeletal muscle oxidative damage. GSE chickens did not exhibit improved performance or reduced skeletal muscle oxidative damage. 4. In conclusion, this study suggests that ERW could partially inhibit ROS-induced oxidative damage to skeletal muscle and improve growth performance in broiler chickens under medium-term chronic heat treatment. PMID:23815735

Azad, M A K; Kikusato, M; Zulkifli, I; Toyomizu, M

2013-01-01

451

Mixed convection boundary layer flow at the lower stagnation point of a sphere embedded in a porous medium in presence of heat source/sink: Constant heat flux case  

NASA Astrophysics Data System (ADS)

The steady mixed convection flow of an incompressible viscous fluid over an isoflux sphere embedded in a porous medium with the existence of heat source/sink is theoretically considered for both the assisting and opposing flow cases with small Prandtl number. The transformed equations of the non-similar boundary layer at the lower stagnation point of the sphere are solved numerically using a finite-difference method known as the Keller-box scheme. Numerical results are presented for the skin friction coefficient and the local wall temperature, as well as the velocity and temperature profiles for different values of the porosity parameter, the heat source/sink parameter and the mixed convection parameter for air. It is noticed that the solution has two branches in a certain range of the mixed convection parameter.

Fauzi, Nur Fatihah; Ahmad, Syakila; Pop, Ioan

2014-07-01

452

Initial findings: The integration of water loop heat pump and building structural thermal storage systems  

SciTech Connect

This report is one in a series of reports describing research activities in support of the US Department of Energy (DOE) Commercial Building System Integration Research Program. The goal of the program is to develop the scientific and technical basis for improving integrated decision-making during design and construction. Improved decision-making could significantly reduce buildings' energy use by the year 2010. The objectives of the Commercial Building System Integration Research Program are: to identify and quantify the most significant energy-related interactions among building subsystems; to develop the scientific and technical basis for improving energy related interactions in building subsystems; and to provide guidance to designers, owners, and builders for improving the integration of building subsystems for energy efficiency. The lead laboratory for this program is the Pacific Northwest Laboratory. A wide variety of expertise and resources from industry, academia, other government entities, and other DOE laboratories are used in planning, reviewing and conducting research activities. Cooperative and complementary research, development, and technology transfer activities with other interested organizations are actively pursued. In this report, the interactions of a water loop heat pump system and building structural mass and their effect on whole-building energy performance is analyzed. 10 refs., 54 figs., 1 tab.

Marseille, T.J.; Johnson, B.K.; Wallin, R.P.; Chiu, S.A.; Crawley, D.B.

1989-01-01