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1

Heat storage medium  

SciTech Connect

A heat storage medium contains (A) a sodium hydroxide in concentration from 60% by weight up to and including the stoichiometric concentration in sodium hydroxide monohydrate, (B) water in concentration from 40% by weight down to and including the said stoichiometric concentration, and (C) 0.1 to 2.0% by weight of tellurium dioxide, all percentages being expressed as percentages by weight of the total weight of sodium hydroxide and water. The tellurium dioxide reduces the tendency of the sodium hydroxide water system to supercool.

Ehlers, J.; Haukelt, H.

1982-08-03

2

Heat storage medium of NaOh-H2O-TeO2  

SciTech Connect

A heat storage medium consists of sodium hydroxide and water, the sodium hydroxide concentration being in the range greater than the stoichiometric concentration in sodium hydroxide monohydrate up to and including 80% by weight, the water concentration being in the range less than the said stoichiometric concentration down to and including 20% by weight. Within this particular concentration range the tendency of the sodium hydroxide water system to supercool diminishes after a few cycles. The initial supercooling may be reduced by the addition of tellurium dioxide in amount 0.1 to 2.0% by weight of the combined weight of sodium hydroxide and water.

Ehlers, J.; Haukelt, H.

1983-02-08

3

Theoretical and Experimental Investigation of the Thermal Behaviour of a High-Temperature Latent Heat Storage System with Sodium Nitrate as Heat Storage Medium.  

National Technical Information Service (NTIS)

The theoretical analysis employs a quasi-two-dimensional mathematical model which includes a specially developed iteration method. The mathematical model was used to investigate the freezing behaviour of the storage medium surrounding a long gas cooled he...

B. Gadhia

1984-01-01

4

Development of a Heat-Storage System for Domestic Application Using a Fused-Salt Hydrate as a Storage Medium. Final Report. Report No. AS/81/10.  

National Technical Information Service (NTIS)

This work was initiated because of the importance of developing compact heat storage systems using phase change materials with high heats of fusion for domestic installation. The innovation investigated in this project was that the PCM would be housed in ...

V. V. Mirkovich

1980-01-01

5

HEATS: Thermal Energy Storage  

SciTech Connect

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

None

2012-01-01

6

Seasonal storage of energy in solar heating  

NASA Astrophysics Data System (ADS)

This paper focuses on several aspects of seasonal storage for space heating using water as the storage medium. The interrelationships between collector area, storage volume, and system performance are investigated using the transient simulation program TRNSYS. The situations for which seasonal storage is most promising are presented. Particular emphasis is placed upon design of seasonal storage systems. A design method is presented which is applicable for storage capacities ranging from a few days to seasonal storage. This design method, coupled with cost information, should be useful in assessing the economic viability of seasonal storage systems. Also investigated are the importance of the load heat exchanger size, tank insulation, collector slope, and year-to-year weather variations in system design.

Braun, J. E.; Klein, S. A.; Mitchell, J. W.

7

Heat storage materials  

SciTech Connect

A heat storage material is described which comprises a mixture of sodium sulfate decahydrate or sodium thiosulfate pentahydrate, and urea. The mixing ratio by mole of the sulfate decahydrate to urea is in the range of 1:1 to 1:3 and the mixing ratio by mole of the thiosulfate pentahydrate to urea is in the range of 1:2 to 1:8.

Takeda, T.; Ikegaya, K.; Kudoh, Y.; Machida, Y.

1985-04-02

8

Low temperature latent heat thermal energy storage - Heat storage materials  

NASA Astrophysics Data System (ADS)

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

Abhat, A.

9

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

Microsoft Academic Search

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

B. Carlsson; A. Schmidt

1983-01-01

10

Active heat exchange thermal storage unit with pentaerythritol  

Microsoft Academic Search

A latent thermal energy storage unit with pentaerythritol was developed, and in the storage unit an active heat transfer enhancement was performed. The phase change material, pentaerythritol, was mixed with a hydrocarbon heat transfer oil and this two-phase storage medium was stirred in a shell-coil type heat exchanger. Through the preliminary experiments in a glass vessel, a lab-scale storage unit

Y. Abe; M. Kamimoto; K. Kanari; T. Ozawa; R. Sakamoto; Y. Takahashi

1984-01-01

11

Heat storage in unsaturated soils: initial theoretical analysis of storage design and operational methods  

Microsoft Academic Search

Unsaturated soil beneath a greenhouse serves as a seasonal storage medium for low temperature heat obtained from solar collectors. The storage configuration consists of an array of vertical helical storage ducts. The computer code PT, developed at Lawrence Berkeley Laboratory, calculates the axisymmetric temperature distribution for a single duct system. Presently heat transfer in the soil is considered to be

C. Doughty; A. Nir; C. F. Tsang; G. S. Bodvarsson

1983-01-01

12

Heat storage module  

NASA Astrophysics Data System (ADS)

Experiments performed on TEXUS 27 sounding rocket to investigate the thermal energy storage module of solar dynamic systems are reported. One of the most suitable energy storage materials for the desired temperature range of 800 to 900 C is lithium fluoride (LiF). Due to the large volume increase during melting of approximately 22% and the corrosivity in the molten state, a canister made of graphite or glass carbon was developed for space use. The heat exchanging wall is equipped with channels and the canister is filled in such a way that molten LiF occupies the whole volume except the channels. In the discharge model, the crystallization of LiF starts at the outer wall and continues towards the center of the canister. There, a void forms due to the volume contraction. The next melting cycle starts again at the heat exchanging wall, and the surplus of volume, due to the pressure of the central void, is able to penetrate the channels against the capillary forces. As soon as the melting front reaches the void, the capillary forces drive the melt out of the channels and a new cycle can start. Tests under terrestrial conditions revealed that the melt did not penetrate the channels as long as the gravity dependent pressure did not exceed the capillary pressure. The TEXUS experiments reported were performed to clarify the following points under microgravity: the melting/freezing behavior of LiF; the formation of the void(s) (Does one void form or several voids? Where is the void located? If several voids are generated, how is their distribution?); and the predicted function of the volume compensation.

Staehle, H. J.; Lindner, F.

1993-02-01

13

Patterned medium for heat assisted magnetic recording  

NASA Astrophysics Data System (ADS)

Heat assisted magnetic recording (HAMR) is a potential solution to extend the limits of conventional magnetic recording. In HAMR, the heating of the recording medium is achieved with a near-field optical transducer. Although the literature suggests novel transducers, there is little consideration of the optical and thermal aspects of the magnetic medium. In this letter we suggest a recording medium that provides a significant enhancement in optical absorption and localized heating. The thermal profiles of the proposed medium and the conventional medium are compared using finite element method solutions of Maxwell's and the heat transfer equations.

?endur, Kür?at; Challener, William

2009-01-01

14

Patterned medium for heat assisted magnetic recording  

Microsoft Academic Search

Heat assisted magnetic recording (HAMR) is a potential solution to extend the limits of conventional magnetic recording. In HAMR, the heating of the recording medium is achieved with a near-field optical transducer. Although the literature suggests novel transducers, there is little consideration of the optical and thermal aspects of the magnetic medium. In this letter we suggest a recording medium

Kürsat Sendur; William Challener

2009-01-01

15

Heat storage in eutectic alloys  

SciTech Connect

Classical thermodynamic equations based on the regular solution approximation yield enthalpic changes for eutectic transformation that agree roughly with values measured for several binary and ternary alloy systems by differential scanning calorimetry or differential thermal analysis. Restricting measurements to binary and ternary alloys of the relatively plentiful elements Al, Cu, Mg, Si and Zn, it has been verified that the best heat storage densities on a mass or volume basis are obtained with alloys rich in Si or Al, elements that have large heats of fusion. Several of these alloys have the highest heat-storage density reported for phase change materials that transform between 780 and 850/sup 0/K. The Mg/sub 2/Si-Si eutectic, which has outstanding storage density at 1219/sup 0/K, illustrates the utility of ordered intermetallic phases with large heat of formation that dissolve in the eutectic liquid to contribute to the entropy change.

Birchenall, C.E. (Univ. of Delaware, Newark, DE); Riechman, A.F.

1980-08-01

16

Heat collection, dissipation and storage  

Microsoft Academic Search

Heat collection and dissipation are provided utilizing a roofing system having a support sheet with an upstanding edge around its periphery and a pair of water impermeable membranes disposed in the volume defined by the support sheet and upstanding edge. Water is pumped from a storage tank to an inlet between the membranes for filling the membranes with water, and

Hager

1985-01-01

17

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

Microsoft Academic Search

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

1984-01-01

18

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

19

The Mediterranean heat storage and Israeli precipitation  

SciTech Connect

The Mediterranean winter storms are intensified by the thermal gradient between the warm sea and intrusions of cold continental air masses. The thermal gradient reflects atmospheric conditions as well as the seasonal heat which is stored in the upper sea. Atmospheric conditions are difficult to predict, yet the heat storage can be measured in the beginning of the winter season. A fair correlation (R = 0.55) was found between the heat storage in the southeast Mediterranean and winter precipitation, and remarkable correlation (R = 0.9) was found between heat storage depletion and precipitation. This allows us to consider the upper heat storage as an index for weather predictions. Small heat storage is associated with annual precipitation which does not exceed the average. Large heat storage will precede winters which are not dryer than the average.

Tzvetkov, E.; Assaf, G.

1982-08-01

20

Heating And Cooling of the Interstellar Medium  

NASA Technical Reports Server (NTRS)

This talk will review the various heating and cooling processes in the interstellar medium. The most important heating processes include the photoelectric effect on dust grains and PAH molecules. Cooling of the gas in the interstellar medium is dominated by emission in the far infrared fine structure lines of OI, CII, SiII, and CI, and the rotational transitions of CO. Many of these lines have been observed from air borne platform, in particular the Kuiper Airborne Observatory. Which of these heating and cooling processes dominates in a given region depends on its physical and especially chemical conditions, which in turn depend themselves on the interstellar UV radiation field. As a result of the interplay of these processes, the interstellar medium is organized in various structures with distinctly different physical conditions (ie., temperature, density, and degree of ionization). Over the last decade, the dominant cooling lines of the neutral interstellar medium have been studied using the Kuiper Airborne Observatory. Because of sensitivity, these observations have concentrated on dense regions illuminated by strong UV fields from nearby stars, so-called Photo Dissociation Regions (PDRs). These observations allow us to study in detail the interaction of UV photons and the interstellar gas and dust. Detailed theoretical models have been developed for PDRs. These will be reviewed and compared to the observations. Finally, anticipated crucial results of future space-based missions (SIRTF, ISO) will be pointed out.

Tielens, Alexander G. G.; Cuzzi, Jeffrey N. (Technical Monitor)

1995-01-01

21

Heat collection, dissipation and storage  

SciTech Connect

Heat collection and dissipation are provided utilizing a roofing system having a support sheet with an upstanding edge around its periphery and a pair of water impermeable membranes disposed in the volume defined by the support sheet and upstanding edge. Water is pumped from a storage tank to an inlet between the membranes for filling the membranes with water, and from an outlet at a drain point for withdrawing water from between the membranes. Air between the membranes is exhausted through a valve. The water storage tank associated with the roofing system has an outer surface with a number of vertical interior divisions defining the volume into compartments. A liquid conduit extends from the top of each conduit to the bottom of the adjacent conduit, and an inlet is provided to the bottom of one of the compartments and an outlet is provided from the top of one of the compartments. Vertical and horizontal stratification of the storage liquid by temperature is provided by the interior divisions and liquid conduits. Electrical controls responsive to temperature sensing at various components operate pumps, valves, and the like to direct liquid flow to the desired components.

Hager, I.V.

1985-04-02

22

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

23

Body Heat Storage and Work in the Heat.  

National Technical Information Service (NTIS)

The development of heat injury during military ground operations in hot environments is a serious risk, particularly when operations in chemical defense ensembles are required. The objective of the research is to develop a model of body heat storage from ...

J. A. Hodgdon

2003-01-01

24

Waste-heat recovery in batch processes using heat storage  

SciTech Connect

The waste-heat recovery in batch processes has been studied using the pinch-point method. The aim of the work has been to investigate theoretical and practical approaches to the design of heat-exchanger networks, including heat storage, for waste-heat recovery in batch processes. The study is limited to the incorporation of energy-storage systems based on fixed-temperature variable-mass stores. The background for preferring this to the alternatives (variable-temperature fixed-mass and constant-mass constant-temperature (latent-heat) stores) is given. It is shown that the maximum energy-saving targets as calculated by the pinch-point method (time average model, TAM) can be achieved by locating energy stores at either end of each process stream. This theoretically large number of heat-storage tanks (twice the number of process streams) can be reduced to just a few tanks. A simple procedure for determining a number of heat-storage tanks sufficient to achieve the maximum energy-saving targets as calculated by the pinch-point method is described. This procedure relies on combinatorial considerations, and could therefore be labeled the combinatorial method for incorporation of heat storage in heat-exchanger networks. Qualitative arguments justifying the procedure are presented. For simple systems, waste-heat recovery systems with only three heat-storage temperatures (a hot storage, a cold storage, and a heat store at the pinch temperature) often can achieve the maximum energy-saving targets. Through case studies, six of which are presented, it is found that a theoretically large number of heat-storage tanks (twice the number of process streams) can be reduced to just a few tanks. The description of these six cases is intended to be sufficiently detailed to serve as benchmark cases for development of alternative methods.

Stoltze, S.; Mikkelsen, J.; Lorentzen, B.; Petersen, P.M.; Qvale, B. [Technical Univ. of Denmark, Lyngby (Denmark). Lab. for Energetics

1995-06-01

25

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

SciTech Connect

A latent cool storage system for load management applications is currently under development at Oak Ridge National Laboratory. This system utilizes a refrigerant gas hydrate as the storage medium and incorporates storage directly into the heat pump cycle. This paper reviews the chemistry of gas hydrates, describes the conceptual heat pump/cool storage system, and presents the results from experiments performed to understand and characterize the kinetics of the R-12 gas hydrate formation process.

Ternes, M.P.

1984-02-01

26

Experimental studies on the behaviours of hydride heat storage system  

NASA Astrophysics Data System (ADS)

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

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

27

Solar heat storage in phase change material  

SciTech Connect

The objective of this project was to develop a chemical heat storage system that had a phase change with release of latent heat at about 105/sup 0/F. The primary reason this kind on system was sought was that heat storage capacity of commonly used storage systems do not match the heat collection capacity of open air collectors. In addition to the phase change three other factors were considered: the cost of the material, the amount of heat the system would hold per unit volume, and the rate at which the system released sensible and latent heat. One hundred nineteen tests were made on 32 systems. Only data on six of the more promising are presented. In the six systems, borax was used as the major component with other materials used as nucleating agents toraise the temperature of phase change.

Phillips, H.J.

1984-02-28

28

An Assessment of Nuclear Isomers as an Energy Storage Medium  

SciTech Connect

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

Hartouni, E P

2008-12-08

29

Fusible pellet transport and storage of heat  

NASA Technical Reports Server (NTRS)

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

Bahrami, P. A.

1982-01-01

30

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

31

Soil Heat Storage Measurements in Energy Balance Studies  

Microsoft Academic Search

Energy balance studies require knowledge of the heat flux at the soil surface. This flux is determined by summing the heat flux at a reference depth (zr) some centimeters below the surface and the rate of change of heat storage in the soil above zr. The rate of change of heat storage, or heat storage for short (DS), is calculated

Tyson E. Ochsner; Thomas J. Sauer; Robert Horton

2007-01-01

32

A novel latent heat storage for solar space heating systems - Refrigerant storage  

NASA Astrophysics Data System (ADS)

This paper proposes a novel latent heat storage which is applicable to solar space heating systems. The device is similar to an absorption refrigerator and stores liquid refrigerant which is subsequently evaporated to release the latent heat. It will recover the energy in a heat pump mode for application to solar space heating systems which are seen to be more cost effective - and hence to have a better market potential - than space cooling systems.

Sheridan, N. R.; Kaushik, S. C.

1981-11-01

33

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

34

Investigation of a new heat-pipe\\/latent-heat-storage receiver element for solar dynamic space power systems  

Microsoft Academic Search

A new latent heat storage technique for space applications is described which uses LiF as the storage medium in graphite capsules with internal capillary notches to accommodate volume change upon melting. A reference receiver of a typical 25 kW(e) solar dynamic power system with 61 integrated heat pipes with externally mounted toroidal LiF-in-graphite capsules is defined. Theoretical calculations of the

Siegfried Krause

1992-01-01

35

Position paper -- Waste storage tank heat removal.  

National Technical Information Service (NTIS)

The purpose of this paper is to develop and document a position on the heat removal system to be used on the waste storage tanks currently being designed for the Multi-Function Waste Tank Facility (MWTF), project W-236A. The current preliminary design for...

M. D. Stine

1995-01-01

36

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

37

Heat transfer enhancement in latent heat thermal storage system for buildings  

Microsoft Academic Search

In this article a review of heat storage technologies with phase change materials (PCMs) is given. In addition, we present paraffin as phase change material in solar heat storage wall with proposals of heat transfer enhancement. The mathematical model for heat transport in heat storage is made. The results obtained with the simulation gives the time dynamics of heat accumulation

Uroš Stritih

2003-01-01

38

Heat pipe effect in porous medium  

SciTech Connect

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

Joseph, M.

1992-12-01

39

German central solar heating plants with seasonal heat storage  

SciTech Connect

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

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

2010-04-15

40

Development of composite latent/sensible heat storage media  

NASA Astrophysics Data System (ADS)

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

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

1990-12-01

41

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

Microsoft Academic Search

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

S. C. Kaushik

1982-01-01

42

Heat Storage Characteristics of Latent-Heat Microcapsule Slurry Using Hot Air Bubbles by Direct-Contact Heat Exchange  

Microsoft Academic Search

This study deals with the heat storage characteristics of latent-heat microcapsule slurry consisting of a mixture of fine microcapsules packed with latent-heat storage material and water. The heat storage operation for the latent-heat microcapsules was carried out by the direct-contact heat exchange method using hot air bubbles. The latent-heat microcapsule consisted of n-paraffin as a core latent-heat storage material and

Hideo Inaba; Akihiko Horibe; Myoung-Jun Kim; Hirofumi Tsukamoto

2001-01-01

43

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

44

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

45

Increasing Soil Heat Storage across Northern Eurasia  

NASA Astrophysics Data System (ADS)

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

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

2009-12-01

46

Eutectic mixtures for solar heat storage  

Microsoft Academic Search

Several inorganic eutectic mixtures which have melting points in a range most suitable for solar heat storage and which have high heats of fusion were investigated. Thermodynamic properties of LiNO3-NH4NO3-NH4Cl, LiNO3-NH4NO3-NaNO3, LiNO3-NH4NO3-KNO3, Mg(NO3)2.6H2O-MgCl2.6H2O, and Mg(NO3)2.6H2O-MgBr2.6H2O are reported. Supercooling, corrosion, and other problems associated with practical application of the eutectic mixtures are examined, the heat content of one system is calculated,

N. Yoneda; S. Takanashi

1978-01-01

47

Information storage medium and method of recording and retrieving information thereon  

DOEpatents

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

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

1986-01-01

48

Thermal-energy storage for process-heat building applications  

SciTech Connect

An assessment is made of energy storage for agricultural and industrial process heat applications and for space heating and cooling and water heating for residential and commercial buildings. The purpose is to identify these storage technologies that have the greatest potential to enhance the commercialization of the most promising solar thermal technologies. In the agricultural and industrial process heat application, the three solar thermal systems investigated are parabolic troughs, parabolic dishes, and central receivers, and the storage systems are mixed-tank, thermocline, two-tank, and phase change. For buildings, phase-change storage in active solar heating and cooling systems were studied in detail for two cities.

Kriz, T.; Christensen, C.; Gaul, H.; Leach, J.; Rabl, A.; Sillman, S.; Swet, C.J.; Ullman, J.

1983-06-01

49

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

50

Heat-Pump Cool Storage in a Clathrate of Freon.  

National Technical Information Service (NTIS)

Presented are the analytical description and assessment of a unique heat pump/storage system in which the conventional evaporator of the vapor compression cycle is replaced by a highly efficient direct contact crystallizer. The thermal storage technique r...

J. J. Tomlinson

1982-01-01

51

Tidal Heating and Convection in the Medium Sized Icy Satellites  

Microsoft Academic Search

Surface features of some icy satellites indicate that the satellites are modified due to the internally driven tectonic activity. Convection could be one of the processes responsible for the formation of the surface features. The potential sources of energy inside the satellites are discussed. For the medium sized icy satellites the radiogenic and tidal heat sources seem to be of

L. Czechowski; J. Leliwa-Kopystynski

2003-01-01

52

Storage of platelets in balanced salt solutions: a simple platelet storage medium.  

PubMed

When a commercially available intravenous solution, plasmalyte-A, was added to platelet pellets as a platelet storage medium (PSM) after more than 85 percent of the plasma had been expressed, the platelets functioned equally well, after 5 days of storage, in platelet aggregation, release reaction, and serotonin uptake as did platelets stored in plasma. The level of fibrinopeptide A was significantly different in the PSM. Similarly, lower levels of kallikrein and complement components in the PSM-stored platelets indicated reduced activation of plasma enzyme systems. Morphology scores showed better shape maintenance in PSM, with values of 255 versus values of 185 in plasma (time zero, 280); electron microscopy also showed somewhat better structural maintenance in PSM. Glucose consumption, lactate and ammonia production, and fatty acid oxidation were also reduced in PSM. No significant differences in pH, white cell count, pO2, pCO2, or lactic dehydrogenase were observed after 5 days of storage in plasma or PSM; however, platelet counts were reduced after 5 days in plasma but remained constant in PSM. The beta-thromboglobulin release was significantly lower in the PSM-stored platelets after 5 days. The volume of platelet membrane glycoprotein lb (which is responsible for platelet adhesion) decreased 15 percent in plasma following storage, whereas a decrease of only 5 percent was noted in PSM. There was less leaching of plasticizers in PSM than in plasma. Survival and recovery using 51Cr-labeled autologous platelets showed that, after 5 days of storage, the recovery of PSM-stored platelets was 63 percent and the survival was 7.7 +/- 0.8 days (multiple hit model).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1824731

Rock, G; White, J; Labow, R

1991-01-01

53

Fractional Cattaneo heat equation in a semi-infinite medium  

NASA Astrophysics Data System (ADS)

To better describe the phenomenon of non-Fourier heat conduction, the fractional Cattaneo heat equation is introduced from the generalized Cattaneo model with two fractional derivatives of different orders. The anomalous heat conduction under the Neumann boundary condition in a semi-infinity medium is investigated. Exact solutions are obtained in series form of the H-function by using the Laplace transform method. Finally, numerical examples are presented graphically when different kinds of surface temperature gradient are given. The effects of fractional parameters are also discussed.

Xu, Huan-Ying; Qi, Hai-Tao; Jiang, Xiao-Yun

2013-01-01

54

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

55

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

56

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

57

Iterative data reconstruction in a thin photonic data storage medium using three-dimensional absorbers in a scattering volume medium.  

PubMed

Iterative data reconstruction in a thin photonic data storage medium using three-dimensional (3D) absorbers in a highly scattering medium is presented for secure data storage. 3D absorbers are used as data. A highly scattering medium protects data to measure 3D absorbers without knowledge of the scattering coefficient distribution because the phase information is lost during multiple scattering. This prevents an interferometer from measuring the volume medium. To recover the 3D absorbers, a 3D scattering coefficient distribution model is used as prior information and then an iterative method is applied to reduce the difference between the measured and numerical output intensity distributions. A preliminary numerical evaluation is presented. PMID:19340197

Matoba, Osamu; Fujimoto, Kodo; Nitta, Kouichi

2009-04-01

58

Heat Storage Characteristics of Latent-Heat Microcapsule Slurry Using Hot Air Bubbles by Direct-Contact Heat Exchange  

NASA Astrophysics Data System (ADS)

This study deals with the heat storage characteristics of latent-heat microcapsule slurry consisting of a mixture of fine microcapsules packed with latent-heat storage material and water. The heat storage operation for the latent-heat microcapsules was carried out by the direct-contact heat exchange method using hot air bubbles. The latent-heat microcapsule consisted of n-paraffin as a core latent-heat storage material and melamine resin as a coating substance. The relationship between the completion time of latent-heat storage and some parameters was examined experimentally. The nondimensional correlation equations for temperature efficiency, the completion time period of the latent-heat storage process and variation in the enthalpy of air through the microcapsule slurry layer were derived in terms of the ratio of microcapsule slurry layer height to microcapsule diameter, Reynolds number for airflow, Stefan number and modified Stefan number for absolute humidity of flowing air.

Inaba, Hideo; Horibe, Akihiko; Kim, Myoung-Jun; Tsukamoto, Hirofumi

59

Model of Direct Contact Heat Transfer for Latent Heat Energy Storage.  

National Technical Information Service (NTIS)

Direct contact heat transfer is an attractive method to reduce the cost of heat exchange for latent heat thermal energy storage systems. However, current performance information is insufficient to allow an accurate appraisal of its economic and technical ...

M. E. Cease

1980-01-01

60

Heat-pump cool storage in a clathrate of freon  

Microsoft Academic Search

Presented are the analytical description and assessment of a unique heat pump\\/storage system in which the conventional evaporator of the vapor compression cycle is replaced by a highly efficient direct contract crystallizer. The thermal storage technique requires the formation of a refrigerant gas hydrate (a clathrate) and exploits an enthalpy of reaction comparable to the heat of fusion of ice.

J. J. Tomlinson

1982-01-01

61

Heat Storage Capacity of Gelled Coolants in ice Vests  

Microsoft Academic Search

A number of ice vest manufacturers offer cooling garments containing gelled coolant rather than pure water. No data has been provided on the heat storage capacity of gelled coolants, however, or on product-specific guidelines for the use of these ice vests. An experiment was designed to compare the heat storage capacity of three commercial ice vests containing gelled coolant materials

SHELDON R. COLEMAN

1989-01-01

62

Heat pipe cooling system for underground, radioactive waste storage tanks  

Microsoft Academic Search

An array of 37 heat pipes inserted through the central hole at the top of a radioactive waste storage tank will remove 100,000 Btu\\/h with a heat sink of 70°F atmospheric air. Heat transfer inside the tank to the heat pipe is by natural convection. Heat rejection to outside air utilizes a blower to force air past the heat pipe

K. C. Cooper; F. C. Prenger

1980-01-01

63

A solar air collector with integrated latent heat thermal storage  

NASA Astrophysics Data System (ADS)

Simulations of the behaviour of a solar air collector with integrated latent heat thermal storage were performed. The model of the collector was created with the use of coupling between TRNSYS 17 and MATLAB. Latent heat storage (Phase Change Material - PCM) was integrated with the solar absorber. The model of the latent heat storage absorber was created in MATLAB and the model of the solar air collector itself was created in TRNSYS with the use of TYPE 56. The model of the latent heat storage absorber allows specification of the PCM properties as well as other parameters. The simulated air collector was the front and back pass collector with the absorber in the middle of the air cavity. Two variants were considered for comparison; the light-weight absorber made of sheet metal and the heat-storage absorber with the PCM. Simulations were performed for the climatic conditions of the Czech Republic (using TMY weather data).

Charvat, Pavel; Ostry, Milan; Mauder, Tomas; Klimes, Lubomir

2012-04-01

64

Heat Transfer Modeling of Dry Spent Nuclear Fuel Storage Facilities  

SciTech Connect

The present work was undertaken to provide heat transfer model that accurately predicts the thermal performance of dry spent nuclear fuel storage facilities. One of the storage configurations being considered for DOE Aluminum-clad Spent Nuclear Fuel (Al-SNF), such as the Material and Testing Reactor (MTR) fuel, is in a dry storage facility. To support design studies of storage options a computational and experimental program has been conducted at the Savannah River Site (SRS). The main objective is to develop heat transfer models including natural convection effects internal to an interim dry storage canister and to geological codisposal Waste Package (WP). Calculated temperatures will be used to demonstrate engineering viability of a dry storage option in enclosed interim storage and geological repository WP and to assess the chemical and physical behaviors of the Al-SNF in the dry storage facilities. The current paper describes the modeling approaches and presents the computational results along with the experimental data.

Lee, S.Y.

1999-01-13

65

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

66

Research of the heat storage time on solar water energy storage floor  

Microsoft Academic Search

On the base of the getting best action of the phase change material (PCM) properties, a new radiant heating structure of the energy storage floor by solar hot water is designed, which was to put heat pipes in PCM layer, without concrete in it. The PCM thermal storage time is mainly studied when the floor surface temperature is admired under

Lin Qiu; Yue Zou; Li Huang

2010-01-01

67

Chemical heat pump and chemical energy storage system  

DOEpatents

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

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

1985-08-06

68

Heat-pump cool storage in a clathrate of freon  

NASA Astrophysics Data System (ADS)

Presented are the analytical description and assessment of a unique heat pump/storage system in which the conventional evaporator of the vapor compression cycle is replaced by a highly efficient direct contract crystallizer. The thermal storage technique requires the formation of a refrigerant gas hydrate (a clathrate) and exploits an enthalpy of reaction comparable to the heat of fusion of ice. Additional system operational benefits include cool storage at the favorable temperatures of 4 to 7 C (40 to 45 F), and highly efficient heat transfer ates afforded by he direct contact mechanism. In addition, the experimental approach underway at ORNL to study such a system is discussed.

Tomlinson, J. J.

69

Heat-pump cool storage in a clathrate of freon  

SciTech Connect

Presented are the analytical description and assessment of a unique heat pump/storage system in which the conventional evaporator of the vapor compression cycle is replaced by a highly efficient direct contact crystallizer. The thermal storage technique requires the formation of a refrigerant gas hydrate (a clathrate) and exploits an enthalpy of reaction comparable to the heat of fusion of ice. Additional system operational benefits include cool storage at the favorable temperatures of 4 to 7/sup 0/C (40 to 45/sup 0/F), and highly efficient heat transfer rates afforded by the direct contact mechanism. In addition, the experimental approach underway at ORNL to study such a system is discussed.

Tomlinson, J.J.

1982-01-01

70

Low and medium heating value coal gas catalytic combustor characterization  

NASA Technical Reports Server (NTRS)

Catalytic combustion with both low and medium heating value coal gases obtained from an operating gasifier was demonstrated. A practical operating range for efficient operation was determined, and also to identify potential problem areas were identified for consideration during stationary gas turbine engine design. The test rig consists of fuel injectors, a fuel-air premixing section, a catalytic reactor with thermocouple instrumentation and a single point, water cooled sample probe. The test rig included inlet and outlet transition pieces and was designed for installation into an existing test loop.

Schwab, J. A.

1982-01-01

71

Shock-Bubble Heating of the Intracluster Medium  

NASA Astrophysics Data System (ADS)

Active galactic nuclei (AGN) Feedback via extragalactic jets requires a thermalization of the energy injected into the intracluster medium (ICM) in order for energy feedback to occur. Heinz and Churazov (2005) proposed a method using shock waves and previously inflated bubbles in the ICM to extract energy from the shock waves and turn the energy into rotational kinetic energy. This energy would decay and allow heating to occur elsewhere throughout the galaxy cluster. In this paper, we extend to three dimensions (3D) the previous work using hydrodynamic simulations. We also compare our results to previous related work done performed experimentally.

Friedman, Samuel H.; Heinz, S.; Churazov, E.

2011-01-01

72

Flexible Storage Medium for Write-Once Optical Tape.  

National Technical Information Service (NTIS)

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 deposite...

A. J. G. Strandjord S. P. Webb D. J. Perettie R. A. Cipriano

1993-01-01

73

Quantifying the effects of heating temperature, and combined effects of heating medium pH and recovery medium pH on the heat resistance of Salmonella typhimurium.  

PubMed

The influence of heating treatment temperature, pH of heating and recovery medium on the survival kinetics of Salmonella typhimurium ATCC 13311 is studied and quantified. From each non-log linear survival curve, Weibull model parameters were estimated. An average shape parameter value of 1.67 was found, which is characteristic of downward concavity curves and is in agreement with values estimated from other S. typhimurium strains. Bigelow type models quantifying the heating temperature, heating and recovery medium pH influences are fitted on scale parameter delta data (time of first decimal reduction), which reflects the bacterial heat resistance. The estimate of z(T) (4.64 degrees C) is in the range of values given in the literature for this species. The influence of pH of the heating medium on the scale parameter (z(pH): 8.25) is lower than that of the recovery pH medium influence (z(')(pH): 3.65). PMID:17292502

Leguérinel, I; Spegagne, I; Couvert, O; Coroller, L; Mafart, P

2007-05-01

74

Kerava Solar Village - A Solar Assisted Heat Pump System with Long-Term Heat Storage.  

National Technical Information Service (NTIS)

The Kerava solar village is the first regional building complex in Finland with a combined solar heating and heat pump system using seasonal storage. Besides the operational principles, we present the findings of a cost, performance and sensitivity analys...

R. Maekinen P. D. Lund

1983-01-01

75

Heat-Pump Cool Storage in a Clathrate of Freon.  

National Technical Information Service (NTIS)

This paper presents the analytical description and preliminary technical assessment of a unique heat pump/storage system in which the conventional evaporator of the vapor compression cycle is replaced by a highly efficient direct contact crystallizer. The...

J. J. Tomlinson

1982-01-01

76

Storage-stable foamable polyurethane is activated by heat  

NASA Technical Reports Server (NTRS)

Polyurethane foamable mixture remains inert in storage unit activated to produce a rapid foaming reaction. The storage-stable foamable composition is spread as a paste on the surface of an expandable structure and, when heated, yields a rigid open-cell polyurethane foam that is self-bondable to the substrate.

1966-01-01

77

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

Microsoft Academic Search

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

S. M. Hasnain

1998-01-01

78

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

79

Model of a Seasonal Heat Storage.  

National Technical Information Service (NTIS)

At present there exist no comprehensive bases to calculate the thermal behavior of large flat seasonal storage reservoirs. The objective of this project is the development of a numerical model which includes all parameters influencing the temperature dist...

W. Adae D. Striebel

1981-01-01

80

Direct contact heat exchange for latent heat-of-fusion energy storage systems  

Microsoft Academic Search

Rudimentary computational and experimental results are presented for a thermal energy storage process based on a novel counter current, direct contact heat exchange concept, the shot tower. The process uses a phase change material and a mutually immiscible heat transfer fluid. A two-tank storage system is used, one each for cool and hot phase change material, respectively. In use, the

M. C. Nichols; R. M. Green

1977-01-01

81

Heat pump cool storage in a clathrate of freon  

SciTech Connect

This paper presents the analytical description and preliminary technical assessment of a unique heat pump/storage system in which the conventional evaporator of the vapor compression cycle is replaced by a highly efficient direct contact crystallizer. The thermal storage technique requires the formation of a refrigerant gas hydrate (a clathrate) and exploits an enthalpy of reaction comparable to the heat of fusion of ice. Additional system operational benefits include cool storage at the favorable temperatures of 4-7/sup 0/C (40-45/sup 0/F), and highly efficient heat transfer rates afforded by the direct contact mechanism. In addition, the possibility of using this technique to provide isothermal storage at higher temperature levels is discussed.

Tomlinson, J.J.

1982-08-01

82

Heat-pump cool storage in a clathrate of freon  

SciTech Connect

This paper presents the analytical description and preliminary technical assessment of a unique heat pump/storage system in which the conventional evaporator of the vapor compression cycle is replaced by a highly efficient direct contact crystallizer. The thermal storage technique requires the formation of a refrigerant gas hydrate (a clathrate) and exploits an enthalpy of reaction comparable to the heat of fusion of ice. Additional system operational benefits include cool storage at the favorable temperatures of 4 to 7/sup 0/C (40 to 45/sup 0/F), and highly efficient heat transfer rates afforded by the direct contact mechanism. In addition, the possibilities of using this technique to provide isothermal storage at higher temperature levels is discussed.

Tomlinson, J.J.

1982-01-01

83

Second Law Optimization of a Sensible Heat Thermal Energy Storage System with a Distributed Storage Element.  

National Technical Information Service (NTIS)

This numerical study defined the behavior of a sensible heat thermal energy storage system whose physical design and operation had been optimized to minimize the production of thermodynamic irreversibilities. It included the effects of transient conductio...

M. J. Taylor

1986-01-01

84

High-capacity hydrogen storage medium: Ti doped fullerene  

NASA Astrophysics Data System (ADS)

Using density functional theory, it is shown that titanium doped heterofullerene has superior property of hydrogen storage. The single titanium atom lies at a double bond position of C60 and bonds to four carbons by Dewar interaction. Each titanium atom binds up to six hydrogen molecules. The first and second hydrogen molecules are dissociated to form carbon hydrides with binding energy of -0.43 eV/H. The other four adsorptions are molecular with binding energy of -0.14 eV/H2. For substitutionally dope C60 with six titanium atoms, the gravimetric density of hydrogen reaches the 7.7 wt % limit necessary for applications in the mobile industry.

Guo, Jun; Liu, Zhiguo; Liu, Suqin; Zhao, Xuehui; Huang, Kelong

2011-01-01

85

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; Kaduchová, Katarína; Papu?ík, Štefan; Janda?ka, Jozef

2014-03-01

86

Aquifer thermal energy (heat and chill) storage  

NASA Astrophysics Data System (ADS)

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

Jenne, E. A.

1992-11-01

87

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

88

Integrated heat pipe-thermal storage system performance evaluation  

SciTech Connect

Performance verification tests of an integrated heat pipe-thermal energy storage system have been conducted. This system is being developed as a part of an Organic Rankine Cycle-Solar Dynamic Power System (ORC-SDPS) receiver for future space stations. The integrated system consists of potassium heat pipe elements that incorporate thermal energy storage (TES) canisters within the vapor space along with an organic fluid (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 surface of the heat pipe elements of the ORC-SDPS receiver and is internally transferred by the potassium vapor for use and storage. 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 stored energy in the TES units is transferred by the potassium vapor to the toluene heater tube. A developmental heat pipe element was fabricated that employs axial arteries and a distribution wick connecting the wicked TES units and the heater to the solar insolation surface of the heat pipe. Tests were conducted to verify the heat pipe operation and to evaluate the heat pipe/TES units/heater tube operation by interfacing the heater unit to a heat exchanger.

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

1987-01-01

89

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

90

Latent heat thermal storage for solar dynamic power generation  

SciTech Connect

Latent heat thermal storage is very attractive for space-based solar dynamic power systems. In this article, we describe a solar receiver unit (SRU) integrated with a phase change thermal storage facility. A two-dimensional model has been set up to simulate the transient behavior of the system. The resulting equations have been solved numerically by the finite difference method, and a parametric study on the performances of the SRU has been conducted; the results are presented and discussed.

Bellecci, C. (Universita della Calabria, Rende (Italy)); Conti, M. (Universita di Camerino (Italy))

1993-09-01

91

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

92

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

93

CD-Recordable: The New Storage Medium for Business and Pleasure.  

ERIC Educational Resources Information Center

Describes CD-Recordable (Compact Disk-Recordable) as an economical information storage medium. Business and government applications are discussed, including prototyping, archiving and back-up, sales, marketing, accounting, and customer support and service. Future possibilities are also considered. (LRW)

Kalstrom, David

1994-01-01

94

Conversion of medium and low temperature heat to power  

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

95

Prolonging storage time of baby ginger by using a sand-based storage medium and essential oil treatment.  

PubMed

Wilt and rot occur readily during storage of baby ginger because of its tender skin and high moisture content (MC). A storage medium, which consisted of sand, 20% water, and 3.75% super absorbent polymers delayed weight loss and loss of firmness at 12 °C and 90% relative humidity. Microorganisms were isolated and purified from decayed rhizomes; among these, 3 fungi were identified as pathogens. The results of 18S rDNA sequence analysis showed that these fungi belonged to Penicillium, Fusarium, and Mortierella genera. The use of essential oil for controlling these pathogens was then investigated in vitro. Essential oils extracted from Cinnamomum zeylanicum (cinnamon) and Thymus vulgaris (thyme) completely inhibited the growth of all of the above pathogens at a concentration of 2000 ppm. Cinnamon oil showed higher antifungal activity in the drug sensitivity test with minimal fungicidal concentration (<500 ppm against all pathogens). In the in vivo test, cinnamon fumigation at a concentration of 500 ppm reduced infection rates of Penicillium, Fusarium, and Mortierella by 50.3%, 54.3%, and 60.7%, respectively. We recommended cinnamon oil fumigation combined with medium storage at 12 °C as an integrated approach to baby ginger storage. PMID:24547773

Liu, Ji; Sui, Guoliang; He, Yongzhou; Liu, Dongjie; Yan, Jing; Liu, Shuxiang; Qin, Wen

2014-04-01

96

Thermal properties of heat storage composites containing multiwalled carbon nanotubes  

NASA Astrophysics Data System (ADS)

Thermal performance enhanced heat storage nanocomposites consisting of palmitic acid (PA) and multiwalled carbon nanotubes (CNTs) were prepared by dispersing chemically treated CNTs into melting PA. The PA/CNT composites remain stable after repeating energy storage and release 80 times. The melting point and latent heat capacity decrease with an increase in the mass fraction of CNTs. PA/CNT composites have enhanced thermal conductivities compared to pure PA, with the enhancement ratios increasing with the mass fraction of CNTs. For PA/CNT composite containing CNTs with a mass fraction of 5.0%, the thermal conductivity enhancement ratios amount up to 36% and 56% in solid and liquid states, respectively.

Wang, Jifen; Xie, Huaqing; Xin, Zhong

2008-12-01

97

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

98

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

PubMed

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

Park, Sinjeung; Won Hahn, Jae

2009-10-26

99

Latent heat thermal energy storage: Determination of properties of storage media and development of a new transfer system  

NASA Astrophysics Data System (ADS)

A latent heat storage system for low temperature solar heating applications was developed. Latent heat storage materials were studied and a heat exchanger design was evaluated. Thermophysical properties of 14 organic and inorganic heat storage materials, including 5 inexpensive commercial paraffins, 2 fatty acids, and 5 salt hydrates, were measured with a precision differential scanning calorimeter. Data pertaining to phase transition temperature, enthalphy and, specific heat of the heat storage materials in solid and liquid phases were taken. The influence of thermal cycling on the melting and freezing behavior of the materials and on changes in thermophysical properties was analyzed. A heat exchanger with finned annulus heat exchanger elements was investigated. Tests were performed, using two laboratory models that employed a paraffin, two fatty acids and one salt hydrate as heat storage materials.

Abhat, A.; Aboul-Enein, S.; Malatidis, N. A.

1982-01-01

100

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

101

Determination of body heat storage in clothing: calorimetry versus thermometry  

Microsoft Academic Search

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

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

1995-01-01

102

Direct contact heat exchange for latent heat-of-fusion energy storage systems  

Microsoft Academic Search

A computational-experimental work is performed to assess the feasibility of the 'shot tower' latent heat of fusion energy storage concept. The shot tower system uses mutually immiscible heat-transfer-fluid\\/phase-change-material pairs of different density in such a way that both the heat transfer fluid and the phase change material move. It is shown that a shot-tower-type heat exchanger using water\\/paraffin and having

M. C. Nichols; R. M. Green

1978-01-01

103

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

NASA Astrophysics Data System (ADS)

This report describes an investigation of a latent cool storage system which employs a refrigerant gas hydrate as the storage medium. A refrigerant gas hydrate is a compound consisting of a refrigerant gas molecule contained within a crystalline water molecule cage. In this system, the storage component is incorporated directly into the refrigeration cycle, replacing the conventional evaporator. The refrigerant is used not only to form the gas hydrate, but also as a direct contact heat exchange fluid to remove heat from the storage tank. In this investigation, only the charging phase of the process was examined; that is, only the characteristics of the formation of gas hydrate were studied. The results of the tests showed that liquid refrigerant must be dispersed throughout the water in the storage tank during charging to obtain acceptance.

Ternes, M. P.

1985-07-01

104

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

SciTech Connect

This report describes an investigation of a latent cool storage system which employs a refrigerant gas hydrate as the storage medium. A refrigerant gas hydrate is a compound consisting of a refrigerant gas molecule contained within a crystalline water molecule cage. In this system, the storage component is incorporated directly into the refrigeration cycle, replacing the conventional evaporator. The refrigerant is used not only to form the gas hydrate, but also as a direct contact heat exchange fluid to remove heat from the storage tank. In this investigation, only the charging phase of the process was examined; that is, only the characteristics of the formation of gas hydrate were studied. The results of the tests showed that liquid refrigerant must be dispersed throughout the water in the storage tank during charging to obtain acceptable performance.

Ternes, M.P.

1985-07-01

105

Thermal performance and heat transport in aquifer thermal energy storage  

NASA Astrophysics Data System (ADS)

Aquifer thermal energy storage (ATES) is used for seasonal storage of large quantities of thermal energy. Due to the increasing demand for sustainable energy, the number of ATES systems has increased rapidly, which has raised questions on the effect of ATES systems on their surroundings as well as their thermal performance. Furthermore, the increasing density of systems generates concern regarding thermal interference between the wells of one system and between neighboring systems. An assessment is made of (1) the thermal storage performance, and (2) the heat transport around the wells of an existing ATES system in the Netherlands. Reconstruction of flow rates and injection and extraction temperatures from hourly logs of operational data from 2005 to 2012 show that the average thermal recovery is 82 % for cold storage and 68 % for heat storage. Subsurface heat transport is monitored using distributed temperature sensing. Although the measurements reveal unequal distribution of flow rate over different parts of the well screen and preferential flow due to aquifer heterogeneity, sufficient well spacing has avoided thermal interference. However, oversizing of well spacing may limit the number of systems that can be realized in an area and lower the potential of ATES.

Sommer, W. T.; Doornenbal, P. J.; Drijver, B. C.; van Gaans, P. F. M.; Leusbrock, I.; Grotenhuis, J. T. C.; Rijnaarts, H. H. M.

2013-11-01

106

Survival of heated Bacillus coagulans spores in a medium acidified with lactic or citric acid  

Microsoft Academic Search

The influence of the intensity of heat treatments on the capacity of citric or lactic acid to prevent growth of survivors of Bacillus coagulans spores after 10 days storage at 35°C was studied. In most cases, the number of survivors during storage decreased. The extent of this spore inactivation depended on the intensity of previous heat treatment and the pH

Alfredo Palop; Ana Marco; Javier Raso; Francisco Javier Sala; Santiago Condón

1997-01-01

107

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

SciTech Connect

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

None

2011-11-21

108

Temperaturlagdeling i forsoegsvarmelager. (Temperature stratification in test heat storage facility).  

National Technical Information Service (NTIS)

Measuring and calculation results from the stratified operation of a demonstration heat storage facility with a volume of 500 cubic meters are given. The measuring system and the equipment for the registration of charging during a period of 126 hours and ...

K. Kielsgaard Hansen P. Nordgaard Hansen V. Ussing

1984-01-01

109

Building with integral solar-heat storage--Starkville, Mississippi  

NASA Technical Reports Server (NTRS)

Column supporting roof also houses rock-storage bin of solar-energy system supplying more than half building space heating load. Conventional heaters supply hot water. Since bin is deeper and narrower than normal, individual pebble size was increased to keep airflow resistance at minimum.

1981-01-01

110

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

Microsoft Academic Search

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

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

2002-01-01

111

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

NASA Astrophysics Data System (ADS)

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

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

2012-11-01

112

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

Microsoft Academic Search

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

Charles A. Lurio

1992-01-01

113

Passive thermal storage wall structures for heating and cooling buildings  

SciTech Connect

The invention comprises improvements in masonry block or precast concrete exterior wall construction that integrally combine means for passive heating and cooling of a building. Both thermal storage and heat exchange with the external environment are provided passively by means of thermal storage materials located within the wall structure and vertical conduits formed in the wall structure. The walls are constructed to form parallel vertical siphons to heat or cool interior air by means of cooling or heating exterior air either simultaneously or intermittently depending upon the relative external and building interior temperatures as well as the internal wall temperature. The masonry blocks are modified configurations of the blocks used for conventional construction and are laid up in basically the same manner with the same patterns as conventional construction. At the top and bottom of the walls, however, specialized blocks are laid to provide ingress and egress for the movement of air vertically through the wall. In an alternative embodiment the walls are constructed to form a passive air exchange for the structure. The parallel vertical siphons heat or cool incoming air by means of cooling or heating outgoing air. Thus, in this embodiment air as well as heat are exchanged between the exterior environment and the interior of the structure.

Lee, K.S.

1983-10-25

114

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

115

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

116

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

117

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

NASA Astrophysics Data System (ADS)

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

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

2012-05-01

118

Thermal energy storage: Basics, design, applications to power generation and heat supply  

SciTech Connect

This book discusses the history of thermal energy storage, storage of sensible heat in saturated fluids and in solids, and storage in gas turbine power plants. The author provides chapter bibliographies.

Beckmann, G.; Gilli, P.V.

1984-01-01

119

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

120

Direct contact heat transfer for thermal energy storage  

SciTech Connect

Direct contact heat exchange offers the potential for increased efficiency and lower heat transfer costs in a variety of thermal energy storage sytems. SERI models of direct contact heat transfer based on literature information have identified dispersed phase drop size, the mechanism of heat transfer within the drop, and dispersed phase holdup as the parameters controlling direct contact system performance. However, current information is insufficient to predict these factors a priori. Therefore, tests have been defined and equipment constructed to provide independent determination of drop size, heat transfer mechanism, and hold up. In experiments with heptane dispersed in water, the equation of Kagen et. al. was found to most closely predict the drop size. The velocity at which drop formation changes from dropwise to jetting was overpredicted by all literature correlations. Further experiments are needed to conclusively determine whether the salt in a salt hydrate melt acts to block internal circulation. In addition, the potential of low temperature oil/salt hydrate latent heat storage systems is being evaluated in the laboratory.

Wright, J. D.

1980-11-01

121

Identification of a moving boundary for a heat conduction problem in a multilayer medium  

Microsoft Academic Search

In this paper, we give a uniqueness theorem for the moving boundary of a heat problem in a composite medium. Through solving\\u000a the Cauchy problem of heat equation in each subdomain, we finally find an approximation to the moving boundary for one-dimensional\\u000a heat conduction problem in a multilayer medium. The numerical scheme is based on the use of the method

Y. S. LiT; T. Wei

2010-01-01

122

An experimental study on a regenerative solar still with energy storage medium — Jute cloth  

Microsoft Academic Search

This paper presents a new approach to improve the efficiency of a solar still by introducing a medium to provide large evaporation surface and utilise the latent heat of condensation. This paper deals with the experiments conducted on a conventional single slope solar still and on a regenerative solar still with jute cloth. The conventional still has been modified with

M. Sakthivel; S. Shanmugasundaram; T. Alwarsamy

2010-01-01

123

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

124

Stockholm Project. Rock Engineering Investigation for Heat Storage in the Town Block Hoestvetet.  

National Technical Information Service (NTIS)

Heating of the Suncourt building at Hagsaetra is based on heat from a borehole storage in rock. In conjunction with construction of this storage installation, observations were made during production drilling and the rock body was evaluated. The report gi...

A. Emmelin L. Wahlstroem H. Stille

1987-01-01

125

Aquifer Thermal Energy Storage Costs with a Seasonal Heat Source (Analysis Using AQUASTOR Computer Code).  

National Technical Information Service (NTIS)

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 ...

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

1981-01-01

126

Pomegranate Juice (Punica Granatum): A New Storage Medium for Avulsed Teeth  

PubMed Central

Objective There is evidence indicating that pomegranate juice contains many of the essential properties necessary to retain cell viability and cell proliferation. These properties indicate that pomegranate juice is a suitable storage medium for avulsed teeth. However, this idea has not yet been tested. In this study, the capacity of pomegranate juice (PJ) as a storage medium for retaining avulsed teeth was evaluated. Materials and Methods: PDL fibroblasts were obtained from healthy human premolars and cultured in Dulbecco’s Modified Eagle’s Medium (DMEM). Cultured cells were subjected to different concentrations of pomegranate juice (PJ), 1% Hank’s balanced salt solution (HBSS) and tap water for 1, 3, 6 and 24 hours. PDL cell viability was assessed by the neutral red uptake assay. Results: The results indicated that 7.5% PJ was the most effective solution for maintaining PDL cell viability amongst all the experimental solution’s and time intervals (P<0.05). The results also showed that 1% PJ was as effective as HBSS for maintaining PDL cell viability. The amount of cell viability increased with increasing concentration of PJ at all time intervals (P<0.001). This effect is suggestive of the proliferative potential of PJ solution. Conclusion: In conclusion, PJ can be recommended as a suitable transport medium for avulsed teeth.

Tavassoli-Hojjati, Sara; Aliasghar, Elham; Babaki, Fatemeh Ahmadian; Emadi, Fatemeh; Parsa, Maliheh; Tavajohi, Shohreh; Ahmadyar, Maryam; Ostad, Seyed Nasser

2014-01-01

127

Energy conservation approach for data center cooling using heat pipe based cold energy storage system  

Microsoft Academic Search

In the present paper, design and economics of the novel type of thermal control system for data center cooling using heat pipe based cold energy storage system has been proposed and discussed. Two types of cold energy storage system namely: Ice storage system and cold water storage system are explained and sized for datacenter with heat output capacity of 8800

Xiao Ping Wu; Masataka Mochizuki; Koichi Mashiko; Thang Nguyen; Vijit Wuttijumnong; Gerald Cabsao; Randeep Singh; Aliakbar Akbarzadeh

2010-01-01

128

Heat storage system utilizing phase change materials government rights  

DOEpatents

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

Salyer, Ival O. (Dayton, OH)

2000-09-12

129

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

Microsoft Academic Search

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

A. D. Solomon

1985-01-01

130

(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

131

Heat storage and distribution inside passive-solar buildings  

SciTech Connect

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

Balcomb, J.D.

1983-01-01

132

New CLIVAR research focus: Consistency between planetary heat balance and ocean heat storage  

NASA Astrophysics Data System (ADS)

Climate is very much about exchange of energy in the Earth System, and in particular in the form of heat. Quantifying these exchanges and how it affects our climate system is one of the key challenges faced by the climate research community. In this context, the Ocean-climate system - Variability, Predictability and Change (CLIVAR) project of the World Climate Research Programme (WCRP) has recently established a new research focus on "Consistency between Planetary Heat Balance and Ocean Heat Storage ". The main objective of the CLIVAR cross-cutting activity is to better understand the "role of the ocean in energy uptake " by analyzing consistency of heat budget components as seen by independent global observing systems, including (i) Earth Observation (EO) satellite data, (ii) in-situ measurements of ocean heat content storage changes, and (iii) Ocean reanalysis for heat transports and exchanges. The project aims at a refinement of a scientific framework on consistency between planetary heat balance and ocean heat storage; the evaluation of existing data sets and information products, their uncertainties and their consistency; recommendations on how to improve the observing systems and derived information products, assimilation methods, ocean and climate models and surface fluxes; contributing insights to related climate research topics such as anthropogenic climate change, seasonal climate prediction, decadal variability, predictability and prediction, as well as sea-level variability and change.

von Schuckmann, Karina; Visbeck, Martin; Haines, Keith; Mathieu, Pierre-Philippe; Gulev, Sergey; Barnier, Bernard; Trenberth, Kevin; Clayson, Carol Anne; Loeb, Norman; Palmer, Matthew

2014-05-01

133

Integrated heat exchanger design for a cryogenic storage tank  

NASA Astrophysics Data System (ADS)

Field demonstrations of liquid hydrogen technology will be undertaken for the proliferation of advanced methods and applications in the use of cryofuels. Advancements in the use of cryofuels for transportation on Earth, from Earth, or in space are envisioned for automobiles, aircraft, rockets, and spacecraft. These advancements rely on practical ways of storage, transfer, and handling of liquid hydrogen. Focusing on storage, an integrated heat exchanger system has been designed for incorporation with an existing storage tank and a reverse Brayton cycle helium refrigerator of capacity 850 watts at 20 K. The storage tank is a 125,000-liter capacity horizontal cylindrical tank, with vacuum jacket and multilayer insulation, and a small 0.6-meter diameter manway opening. Addressed are the specific design challenges associated with the small opening, complete modularity, pressure systems re-certification for lower temperature and pressure service associated with hydrogen densification, and a large 8:1 length-to-diameter ratio for distribution of the cryogenic refrigeration. The approach, problem solving, and system design and analysis for integrated heat exchanger are detailed and discussed. Implications for future space launch facilities are also identified. The objective of the field demonstration will be to test various zero-loss and densified cryofuel handling concepts for future transportation applications.

Fesmire, J. E.; Tomsik, T. M.; Bonner, T.; Oliveira, J. M.; Conyers, H. J.; Johnson, W. L.; Notardonato, W. U.

2014-01-01

134

Optical recording medium/system with heat-dissipating and light reflecting layers  

US Patent & Trademark Office Database

An optical recording medium and an optical recording and reproduction device including the same, wherein the optical recording medium comprises a substrate, a reflective layer formed on the substrate, a recording layer formed on the reflective layer, a first protective layer formed on the recording layer and a transparent heat radiating layer formed on the first protective layer for promoting dispersion of heat from the recording layer, and light is focused on the recording layer from an optical system via a side at which the first protective layer is formed to prevent heat buildup, erasure of recorded signals and damage to the optical recording medium.

2005-08-23

135

Analysis of selected surface characteristics and latent heat storage for passive solar space heating  

SciTech Connect

Results are presented of an analysis of the value of various technical improvements in the solar collector and thermal storage subsystems of passive solar residential, agricultural, and industrial systems for two regions of the country. The evaluated improvements are: decreased emissivity and increased absorptivity of absorbing surfaces, decreased reflectivity, and decreased emissivity of glazing surface, and the substitution of sensible heat storage media with phase change materials. The value of each improvement is estimated by the additional energy savings resulting from the improvement.

Fthenakis, V.; Leigh, R.

1981-12-01

136

The effect of heat treatment on high temperature mechanical properties of microalloyed medium carbon steel  

Microsoft Academic Search

In the present work, high temperature tensile properties and abrasive wear performance of a microalloyed medium carbon steel has been examined. Tensile and abrasive wear testing were carried out on as-received and heat treated specimens. The research has shown that microalloyed medium carbon steel was susceptible to dynamic strain ageing due to interaction of mobile dislocations and solid atoms, such

Süleyman Gündüz; Mustafa Acarer

2006-01-01

137

Analysis of Shape of Porous Cooled Medium for an Imposed Surface Heat Flux and Temperature.  

National Technical Information Service (NTIS)

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 the...

R. Siegel

1973-01-01

138

Ray-Tracing Method for Radiative Heat Transfer in a Two-Layer Anisotropic Scattering Medium  

Microsoft Academic Search

Transient radiation heat transfer in a two-layer anisotropic scattering medium is investigated. Each layer of the medium can have different thermal and radiative properties. The two surfaces are assumed to be semitransparent or opaque, and the interface between the two layers is assumed to be semitransparent. Specular reflection is considered at the surfaces and the interface. A general criterion for

Hong-Liang Yi; Ming Xie; He-Ping Tan

2008-01-01

139

Solar storage systems using salt hydrate latent heat and direct contact heat exchange. I - Preliminary design considerations  

Microsoft Academic Search

The operating characteristics of a salt hydrate latent heat storage system, using Glauber's salt and direct contact heat exchange through an immiscible heat transfer fluid, have been studied theoretically. Drop dynamics and heat transfer models from the literature were used to predict the system behavior for a range of conditions involving heat transfer fluid inlet temperature and drop size, composition

A. E. Fouda; G. J. G. Despault; J. B. Taylor; C. E. Capes

1980-01-01

140

Simultaneous defocusing of the aperture and medium on a spectroholographic storage system  

NASA Astrophysics Data System (ADS)

In a spectroholographic storage system the defocusing method is often used to obtain spectrum uniformity and improve the quality of the recorded information. However, defocusing introduces vignette and stronger interpixel cross talk in the marginal field of view. We report a method that defocuses the aperture and medium together. Based on the pixel spread function, two inequalities are introduced to estimate the upper and lower bounds of the energy received at the CCD. We balance the spectrum uniformity with interpixel cross talk and vignette and then allow the designer to select optimal structure values of the defocusing spectroholographic storage system, i.e., the defocusing value, aperture size, and fill factors for the spatial light modulator and CCD.

Wang, Zhuo; Jin, Guofan; He, Qingsheng; Wu, Minxian

2007-08-01

141

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

142

Storage of medium-chain triglycerides in adipose tissue of orally fed infants.  

PubMed

The effect of the fatty acid content of the diet on that of adipose tissue was studied in 5 newborn infants studied prior to feeding and 30 infants fed ad libitum from birth with either human milk or a commercial formula as the sole nutrient. Significant positive linear correlations of dietary intake on adipose tissue content of fatty acids were found for both long- and medium-chain fatty acids (MCFA). Infants stored up to 12% of MCFAs in their subcutaneous fat. The technique of direct transesterification improved the recovery of the volatile MCFAs and could explain the finding that medium-chain triglyceride storage in adipose tissue is more extensive than in previous reports. This study documents that MCFAs are not used solely as a source of energy: they can be reesterified or serve for chain elongation, before being deposited in fat stores. PMID:3812339

Sarda, P; Lepage, G; Roy, C C; Chessex, P

1987-02-01

143

Effect of sperm concentration, medium osmolality and oocyte storage on artificial fertilisation success in a myobatrachid frog (Limnodynastes tasmaniensis)  

Microsoft Academic Search

The present study optimised artificial fertilisation and oocyte storage conditions in Limnodynastes tasmaniensis (Myobatrachidae). Data on general reproductive biology, the effect of sperm motility and concen- tration, medium osmolality and oocyte storage on artificial fertilisation success are presented. Egg number was most strongly correlated with bodyweight (r = 0.819). Sperm yield was correlated with testes weight (r = 0.827), which

D. L. EdwardsA; M. J. Mahony; J. Clulow

2004-01-01

144

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

PubMed

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

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

2010-08-01

145

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

SciTech Connect

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

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

2010-06-15

146

Long Term Solar Heat Storage through Water Tanks for the Heating of Housing.  

National Technical Information Service (NTIS)

The report concerning a research on solar plants fitted with buried water tanks for the interseasonal storage of solar heat. Computer codes for the design of such plants are described, as well as the design and the construction of a prototype solar plant ...

M. Cucumo, V. Marinelli, V. Marinelli, G. Oliveti, A. Sabato

1985-01-01

147

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

PubMed Central

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

Felderhoff, Michael; Bogdanovic, Borislav

2009-01-01

148

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

149

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

150

Thermal energy storage for industrial waste heat recovery  

NASA Technical Reports Server (NTRS)

The potential is examined for waste heat recovery and reuse through thermal energy storage in five specific industrial categories: (1) primary aluminum, (2) cement, (3) food processing, (4) paper and pulp, and (5) iron and steel. Preliminary results from Phase 1 feasibility studies suggest energy savings through fossil fuel displacement approaching 0.1 quad/yr in the 1985 period. Early implementation of recovery technologies with minimal development appears likely in the food processing and paper and pulp industries; development of the other three categories, though equally desirable, will probably require a greater investment in time and dollars.

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

1978-01-01

151

Two Component Thermal Energy Storage Material.  

National Technical Information Service (NTIS)

Effective storage of thermal energy requires a stable storage medium which has a high heat capacity, high rates of heat transfer, and a reasonable system size and cost. A thermal energy storage medium consisting of a slurry of spherically shaped capsules ...

E. M. Mehalick A. T. Tweedie

1975-01-01

152

Spectral Element Approach for Coupled Radiative and Conductive Heat Transfer in Semitransparent Medium  

Microsoft Academic Search

A spectral element method is presented to solve coupled radiative and conductive heat transfer problems in multidimensional semitransparent medium. The solution of radiative energy source is based on a second order radiative transfer equation. Both the second order radiative transfer equation and the heat diffusion equation are discretized by spec- tral element approach. Four various test problems are taken as

J. M. Zhao; L. H. Liu

2007-01-01

153

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

154

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

155

Heat Storage in Aquifers: Buoyancy Flow and Thermal-Stratification Problems.  

National Technical Information Service (NTIS)

Heat Storage in aquifers involves injecting warm water into a confined aquifer and recovering the heat later by pumping out the warm water. Heat loss in the aquifers is roughly proportional to the area of the warm storage region which may be increased to ...

G. Hellstrom C. F. Tsang J. Claesson

1979-01-01

156

Early prediction of the shelf-life of medium-heat whole milk powders using stepwise multiple regression and principal component analysis  

Microsoft Academic Search

Fifteen medium-heat whole milk powders manufactured at the same plant under identical processing conditions from 15 different batches of raw milk were subjected to accelerated storage at 50 °C and a water activity of 0.31 in air. With a view to the development of a new prediction method, 22 chemical and technological variables and 13 time-dependent changes over 2 days

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

1997-01-01

157

Laser heating of uncoated optics in a convective medium.  

PubMed

Powerful, long-pulse lasers have a variety of applications. In many applications, optical elements are employed to direct, focus, or collimate the beam. Typically the optic is suspended in a gaseous environment (e.g., air) and can cool by convection. The variation of the optic temperature with time is obtained by combining the effects of laser heating, thermal conduction, and convective loss. Characteristics of the solutions in terms of the properties of the optic material, laser beam parameters, and the environment are discussed and compared with measurements at the Naval Research Laboratory, employing kW-class, 1 µm wavelength, continuous wave lasers and optical elements made of fused silica or BK7 glass. The calculated results are in good agreement with the measurements, given the approximations in the analysis and the expected variation in the absorption coefficients of the glasses used in the experiments. PMID:22614476

Hafizi, B; Ting, A; Gordon, D F; Sprangle, P; Peñano, J R; Fischer, R F; DiComo, G P; Colombant, D C

2012-05-10

158

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

159

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

SciTech Connect

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

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

1992-10-01

160

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

NASA Astrophysics Data System (ADS)

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.

1992-10-01

161

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

162

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

Microsoft Academic Search

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

A. Grajcar

163

Li-doped B2C graphene as potential hydrogen storage medium  

NASA Astrophysics Data System (ADS)

Based on first-principles density functional theory, we show that Li-doped B2C graphene can serve as a high-capacity hydrogen storage medium with the gravimetric density of 7.54 wt %. The present results indicate that the strong binding of Li onto the substrate comes from the hybridizations of B 2p and C 2p orbitals with the partial occupancy of Li 2p orbitals. Both the polarization mechanism and the orbital hybridizations contribute to the adsorption of H2 molecules and the resulting adsorption energy is in the range of 0.12-0.22 eV/H2. The system reported here is favorable for the reversible hydrogen adsorption/desorption at the room temperature.

An, Hui; Liu, Chun-Sheng; Zeng, Zhi; Fan, Chao; Ju, Xin

2011-04-01

164

Spent fuel dry storage technology development: Electrically heated drywell storage test (3kW operation)  

NASA Astrophysics Data System (ADS)

An electrically heated drywell storage cell test has been in operation since March 1978 at the Engine-Maintenance, Assembly and Disassembly (E-MAD) facility on the Nevada Test Site in support of spent fuel dry storage technology development. The test data obtained at electric heater power output of 3.0 kW is given and the data is compared with that for heater power outputs of 1.0 kW and 2.0 kW. The simulated drywell storage cell consists of a stainless steel canister (representative of the spent fuel canisters being tested at E-MAD) containing an electrical heater assembly, a concrete-filled shield plug to which the canister is attached, and a carbon steel linear that encloses the canister and shield plug. The entire test drywell is grouted into a hole drilled in the soil adjacent to E-MAD. Temperature instrumentation is provided on the exterior of the canister and liner, in the grout around the liner, and at six radial locations in the soil surrounding the drywell. Peak measured canister and liner temperatures are 7850 F and 7470 F, respectively.

Unterzuber, R.; Hanson, J. P.

1981-09-01

165

Analysis of diffusion delay in a layered medium. Application to heat measurements from muscle.  

PubMed Central

An analysis is presented of diffusional delays in one-dimensional heat flow through a medium consisting of several layers of different materials. The model specifically addresses the measurement of heat production by muscle, but diffusion of solute or conduction of charge through a layered medium will obey the same equations. The model consists of a semi-infinite medium, the muscle, in which heat production is spacially uniform but time varying. The heat diffuses through layers of solution and insulation to the center of the thermal element where heat flow is zero. Using Laplace transforms, transfer functions are derived for the temperature change in the center of the thermopile as a function of the temperature at any interface between differing materials or as a function of heat production in the muscle. From these transfer functions, approximate analytical expressions are derived for the time constants which scale the early and late changes in the central temperature. We find that the earliest temperature changes are limited by the diffusivities of the materials, whereas the approach to steady state depends on the total heat capacity of the system and the diffusivity of muscle. Hill (1937) analyzed a similar geometry by modeling the layered medium as a homogeneous system with an equivalent half thickness. We show that his analysis was accurate for the materials in his system. In general, however, and specifically with regard to modern thermopiles, a homogeneous approximation will lead to significant errors. We compare responses of different thermopiles to establish the limits of time resolution in muscle heat records and to correct them for diffusional delays. Using numerical techniques, we invert the Laplace transforms and show the time course of the temperature changes recorded by different instruments in response to different patterns of heat production.

Gilbert, S. H.; Mathias, R. T.

1988-01-01

166

A concept of exchange-coupled recording medium for heat-assisted magnetic recording  

NASA Astrophysics Data System (ADS)

A concept of exchange-coupled magnetic layer is presented for the heat-assisted magnetic recording medium. Magnetic layers with different Curie point (TC) and similar coercivity (Hc) are stacked via exchange coupling. Hc of the double layer changes abruptly at near TC of one of the layers. This means that the recording temperature can be reduced with little reduction in the thermal stability. A medium consisting of two Co/Pd multilayers was fabricated as this medium. The temperature dependence of Hc of the double layer was similar to that of the expected one by a numerical calculation.

Kikitsu, Akira; Kai, Tadashi; Nagase, Toshiyuki; Akiyama, Jun-Ichi

2005-05-01

167

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

SciTech Connect

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

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

1986-12-01

168

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

169

Metal-halide mixtures for latent heat energy storage  

NASA Astrophysics Data System (ADS)

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.

170

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

171

A process steam generator based on the high temperature magnesium hydride\\/magnesium heat storage system  

Microsoft Academic Search

As a first pilot project application of the reversible thermochemical high temperature heat storage system magnesium hydride\\/magnesium a process steam generator has been built and tested. It draws the heat for the generation of superheated steam from a magnesium hydride\\/magnesium (MgH2Mg) heat store and is primarily meant for the storage of high grade industrial waste heat which can be made

B. Bogdanovi?; A. Ritter; B. Spliethoff; K. Stra?burger

1995-01-01

172

High frequency heating of medium density fiberboard (MDF): theory and experiment  

Microsoft Academic Search

Medium-density fiberboard (MDF) is a wood-based panel manufactured from wood fibers with a synthetic adhesive through the conduction of heat from the hot platens. One alternative is the use of high-frequency (HF) heating, which has the advantage of reducing the press cycle, the platens temperature and the post-curing time, with constancy of resin formulation. For this approach, an electromagnetic (EM)

Celeste M. C. Pereira; Calixte Blanchard; Luisa M. H. Carvalho; Carlos A. V. Costa

2004-01-01

173

Thermal response in thermal energy storage material around heat transfer tubes: effect of additives on heat transfer rates  

Microsoft Academic Search

The effects of carbon-fiber chips and carbon brushes as additives on the thermal conductivity enhancement of phase change materials (PCMs) using in latent heat thermal energy storage are investigated experimentally and numerically by considering the wall effect of the additives. The carbon-fiber chips are effective for improving the heat transfer rate in PCMs. However, the thermal resistance near the heat

Yuichi Hamada; Wataru Ohtsu; Jun Fukai

2003-01-01

174

Boiling/evaporative heat transfer from spheres in packed-bed thermal energy storage units  

NASA Astrophysics Data System (ADS)

An experimental study was conducted to study boiling/evaporative heat transfer from heated spheres in vertical packed beds with downward liquid vapor flow of Refrigerant-113. Surface superheats of 1 to 50 C; mass flow rates of 1.7, 2.7, and 5.6 kg/min; sphere diameters of 1.59 and 2.54 cm; quality (i.e., mass fraction of vapor) of the inlet flow of 2 to 100 percent; and two surface roughness conditions were considered. To determine heat transfer coefficients, smooth and roughened aluminum spheres of the same diameter as the other spheres in the bed were instrumented with two thermocouples each for measuring the surface temperatures and a tiny electrical resistance heater for input power. The heat transfer measurements were made under steady-state conditions. Heat transfer coefficients were independently determined for each sphere at three values of surface superheat. The quantitative results are represented as a correlation for the boiling heat transfer coefficients in terms of a homogeneous model. The equation correlates very effectively with the dimensionless temperature difference. The correlation may be used in the development of numerical models to simulate the transient thermal performance of a packed-bed thermal energy storage unit while operating as an evaporator. The boiling of the liquid vapor flow around the spheres in the packed bed was visually observed with a fiber optic boroscope and recorded on a video tape. The visualization results showed qualitatively the presence of our four distinct flow regimes. One of these occurs under subcooled regime. The other three occur under saturated inlet conditions and are referred to as the low-quality, medium-quality, and high-quality regimes. The regimes are discussed in detail.

Arimilli, R. V.; Moy, C. A.

1990-05-01

175

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

NASA Astrophysics Data System (ADS)

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

Guo, Yun; Cao, Weiwu

2013-07-01

176

Heat transfer by conduction and radiation in one-dimensional planar medium using the differential approximation  

Microsoft Academic Search

The combined conduction and radiation heat transfer problem for a gray planar medium between two diffuse, isothermal infinite parallel plates is considered using the differential approximation. The P-1 and P-3 spherical harmonics approximations for the intensity distribution are used. In addition, isotropic scattering and uniform volumetric generation terms are included. The governing energy equations developed using the P-1 and P-3

A. C. Ratzel; J. R. Howell

1981-01-01

177

Application of the P-1 approximation of radiative heat transfer in a non-gray medium  

Microsoft Academic Search

The Spherical Harmonic Method is generalized for consideration of radiative heat transfer in a one-dimensional non-gray medium. Using only the transfer equation and the conservation of energy, results are expressed in terms of the spectral absorption coefficient. In contrast to most of the existing approaches which must utilize results of the total band absorption correlation, the present method is thus

W. W. Yuen; D. J. Rasky

1980-01-01

178

Heat-balance equation for a disk-thermocouple system in an isotropic medium  

Microsoft Academic Search

By means of a variational method, the heat-balance equation is derived for a disk-thermocouple system in a cylindrical tube for various radii of the disk, tube, and thermocouple wires, and for various values of the thermal conductivity of the medium and thermocouple material.

A. V. Rokhlenko; V. A. Lavrenko

1968-01-01

179

Thermal Resistance Minimization of a Fin-and-Porous-Medium Heat Sink with Evolutionary Algorithms  

Microsoft Academic Search

This article presents a conceptual design of a heat sink combining a porous medium whose matrix is highly conductive and a fin. A simplified model is presented to estimate the performance of the system, relying on Darcy law and local thermal equilibrium. The objective is to minimize the hot-spot temperature under global mass constraint by using an optimization procedure based

Maxime Tye-Gingras; Louis Gosselin

2008-01-01

180

Conjugate forced convection flow past a circular cylinder with internal heat generation in a porous medium  

Microsoft Academic Search

Purpose – The aim is to determine the effect of different conductivity ratios on forced convection past a circular cylinder embedded in a porous medium, where the solid cylinder forms a uniform heat source. Design\\/methodology\\/approach – The authors employ an unsteady finite difference method to obtain the resulting steady-state solutions. Interface conditions are applied using the fictitious point method. Findings

Nur F. Abd Kadir; D. A. S. Rees; Ioan Pop

2008-01-01

181

Heat transfer from cylinders during melting of a thermal energy storage material  

Microsoft Academic Search

Melting from an electrically heated single cylinder and an array of three cylinders imbedded in a phase change material (PCM) during the charging cycle of a thermal energy storage (TES) system was studied experimentally. A paraffin (n-octadecane) having a melting temperature of 301 K was used as storage material. A shadowgraph technique was employed to optically determine the local heat

A. G. Bathelt; R. Viskanta; W. Leidenfrost

1978-01-01

182

HEAT TRANSFER ENHANCEMENT IN A LATENT HEAT STORAGE SYSTEM 1 Paper presented at the ISES Solar World Congress, Taejon, South Korea, 24–29 August 1997. 1  

Microsoft Academic Search

Commercial acceptance and the economics of solar thermal technologies are tied to the design and development of efficient, cost-effective thermal storage systems. Thermal storage units that utilize latent heat storage materials have received greater attention in the recent years because of their large heat storage capacity and their isothermal behavior during the charging and discharging processes. One major issue that

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

1999-01-01

183

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

PubMed Central

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

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

2013-01-01

184

Analysis of cooling cycles with clathrate energy storage  

Microsoft Academic Search

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

Gadalla

1988-01-01

185

Development of a hydrogen catalytic heater for heating metal hydride hydrogen storage systems  

Microsoft Academic Search

This paper describes the design, fabrication and performance evaluation of a high efficiency, compact heater that uses the catalytic oxidation of hydrogen to provide heat to a hydrogen storage system. The heater was designed to transfer up to 30kW of heat from the catalytic reaction to the hydrogen storage system via a recirculating heat transfer fluid.The catalytic heater consists of

Terry A. Johnson; Michael P. Kanouff

186

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

NASA Astrophysics Data System (ADS)

Spatial variations of the [S II]/H? and [N II]/H? line intensity ratios observed in the gaseous halo of the Milky Way and other galaxies are inconsistent with pure photoionization models. They appear to require a supplemental heating mechanism that increases the electron temperature at low densities, ne. This would imply that in addition to photoionization, which has a heating rate per unit volume proportional to n2e, there is another source of heat with a rate per unit volume proportional to a lower power of ne. One possible mechanism is the dissipation of interstellar plasma turbulence, which, according to Minter & Spangler, heats the ionized interstellar medium in the Milky Way at a rate of ~1×10-25ne ergs cm-3 s-1. If such a source were present, it would dominate over photoionization heating in regions where ne<~0.1 cm-3, producing the observed increases in the [S II]/H? and [N II]/H? intensity ratios at large distances from the galactic midplane as well as accounting for the constancy of [S II]/[N II], which is not explained by pure photoionization. Other supplemental heating sources, such as magnetic reconnection, cosmic rays, or photoelectric emission from small grains, could also account for these observations, provided they supply ~10-5 ergs s-1 per square centimeter of the Galactic disk to the warm ionized medium.

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

1999-11-01

187

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

PubMed Central

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.

2013-01-01

188

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

189

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

190

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

191

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

192

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

193

Effective-medium model of wire metamaterials in the problems of radiative heat transfer  

NASA Astrophysics Data System (ADS)

In the present work, we check the applicability of the effective medium model (EMM) to the problems of radiative heat transfer (RHT) through so-called wire metamaterials (WMMs)—composites comprising parallel arrays of metal nanowires. It is explained why this problem is so important for the development of prospective thermophotovoltaic (TPV) systems. Previous studies of the applicability of EMM for WMMs were targeted by the imaging applications of WMMs. The analogous study referring to the transfer of radiative heat is a separate problem that deserves extended investigations. We show that WMMs with practically realizable design parameters transmit the radiative heat as effectively homogeneous media. Existing EMM is an adequate tool for qualitative prediction of the magnitude of transferred radiative heat and of its effective frequency band.

Mirmoosa, M. S.; Rüting, F.; Nefedov, I. S.; Simovski, C. R.

2014-06-01

194

Heat transfer in a viscoelastic boundary layer flow through a porous medium  

NASA Astrophysics Data System (ADS)

This paper examines the viscoelastic fluid flow and heat transfer characteristics in a saturated porous medium over an impermeable stretching surface with frictional heating and internal heat generation or absorption. The heat transfer analysis has been carried out for two different heating processes, namely (i) with prescribed surface temperature (PST-case) and (ii) prescribed surface heat flux (PHF-case). The governing equations for the boundary layer flow problem result similar solutions. For the specified five boundary conditions, it is not possible to solve directly the resulting sixth-order nonlinear ordinary differential equation. For the present incompressible boundary layer flow problem with constant physical parameters, the momentum equation is decoupled from the energy equation. Two closed-form solutions for the momentum equation are obtained and identified the realistic solution of the physical problem. Exact solution for the velocity field and the skin-friction are obtained. Also, the solution for the temperature and the heat transfer characteristics are obtained in terms of Kummer's function. Asymptotic results for the temperature function for large Prandtl numbers are presented. The work due to deformation in the energy equation, which is essential and escaped from the attention of researchers while formulating the visco-elastic boundary layer flow problems, is considered. Drastic variation in the values of heat transfer coefficient is observed when the work due to deformation is ignored.

Pillai, K. M. C.; Sai, K. S.; Swamy, N. S.; Nataraja, H. R.; Tiwari, S. B.; Rao, B. N.

195

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

196

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

NASA Astrophysics Data System (ADS)

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

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

2011-04-01

197

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

Microsoft Academic Search

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

Dimitris K. Papanastasiou; Constantinos Kittas

2011-01-01

198

Autologous red cells derived from cord blood: collection, preparation, storage and quality controls with optimal additive storage medium (Sag-mannitol).  

PubMed

To investigate whether packed red cells (PRCs) prepared from autologous cord blood-packed red cells (AC-PRCs) could be used as an alternative for homologous-packed red cells (H-PRCs), we developed a system to collect and prepare AC-PRCs and determined standard storage parameters during 35 days of storage in extended storage medium (Sag-mannitol). We collected and fractionated cord blood from 390 newborns. The amount and quality of the AC-PRCs were analysed. The bacterial contamination rate was 1.84%. Twelve AC-PRCs were stored for 35 days, and standard laboratory parameters were measured at day 1 and day 35. The initial laboratory parameters of the AC-PRCs were similar to the parameters of the H-PRCs. After 35 days, the AC-PRCs displayed an increased haemolysis rate compared to H-PRCs (1.1 versus 0.2%) and also a significant decreased adenosine triphosphate value (1.2 versus 2.3 micromol L(-1)). Haemoglobin, haematocrit and pH were comparable in both groups. AC-PRCs meet the quality criteria for H-PRCs after 35 days. Utilizing a closed collection system for cord blood and an extended storage medium will increase safety and quality and facilitate the routine transfusion of autologous red cells derived from cord blood. PMID:14617341

Garritsen, H S P; Brune, T; Louwen, F; Wüllenweber, J; Ahlke, C; Cassens, U; Witteler, R; Sibrowski, W

2003-10-01

199

Results on the Characterization of Gas Hydrate Formation in a Direct Contact Heat Pump Cool Storage System.  

National Technical Information Service (NTIS)

This report describes an investigation of a latent cool storage system which employs a refrigerant gas hydrate as the storage medium. A refrigerant gas hydrate is a compound consisting of a refrigerant gas molecule contained within a crystalline water mol...

M. P. Ternes

1985-01-01

200

Thermodynamics of heat storage in a PCM shell-and-tube heat exchanger in parallel or in series with a heat engine  

SciTech Connect

This paper addresses the thermodynamics of heat storage in a PCM shell-and-tube heat exchanger, which in a solar power plant is provided to damp the pulsed behaviour of the heat source. Unequal duration of the active and passive phases of the heat source, and consequently of the heat storage and discharge, is allowed. Two alternative schemes of connection of the storage element to the heat engine, referred to as the series and the parallel set-ups, are considered. Using the general framework developed in our previous work, we reformulate the second-law efficiencies for each scheme in terms of a few dimensionless parameters, reflecting the operating conditions of the system and the relevant heat-transfer characteristics of the storage element. For the particular storage system studied in this paper, i.e. the PCM shell-and-tube heat exchanger executing periodic storage-removal cycles, the latter characteristics are determined numerically. A parametric study is conducted to compare the series and parallel schemes with regard to various design objectives. 23 refs., 15 figs., 1 tab.

Conti, M. [Universita` di Camerino (Italy)] [Universita` di Camerino (Italy); Charach, C. [Ben-Gurion Univ. of the Negev, Sede Boqer Campus (Israel)] [Ben-Gurion Univ. of the Negev, Sede Boqer Campus (Israel)

1996-07-01

201

Process and apparatus for heating a transparent, gaseous medium by means of concentrated solar radiation  

US Patent & Trademark Office Database

Between a device (15, 16) for supplying a transparent gaseous medium and a device (17, 18) for exhausting the heated medium, a number of quartz glass pipes (11) are disposed. Within each quartz glass pipe a number of glass strips, running parallel to one another, are accommodated. The adjacent glass strips are held by spacers at a distance which corresponds to the thickness of the glass strips. The glass strips are lightly tinted so that they absorb the incident radiation only partially. The coefficient of absorption of the glass strips amounts to about 0.1, so that about 90% of the incident solar radiation exits from the glass strips again and falls upon a further glass strip. In this way, the insolated energy is distributed over the entirety of the regions of the glass strips, so that all locations of the glass strips are heated evenly, and no location of the glass strips is overheated. The heat in the glass strips is transmitted to the gaseous medium flowing through inside the glass pipes and between the glass strips and is exhausted. This apparatus is particularly suitable for being disposed in a tower of a solar power plant in which the solar rays are directed at the top of the tower by means of a plurality of reflectors disposed on the ground.

1983-12-20

202

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

203

Modeling of fixed bed heat storage units utilizing phase change materials  

NASA Astrophysics Data System (ADS)

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

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

1987-06-01

204

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

National Technical Information Service (NTIS)

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

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

1983-01-01

205

Cascaded latent heat storage for parabolic trough solar power plants  

Microsoft Academic Search

The current revival of solar thermal electricity generating systems (SEGS) unveils the still existing need of economic thermal energy storages (TES) for the temperature range from 250°C to 500°C. The TES-benchmark for parabolic trough power plants is the direct two tank storage, as it was used at the SEGS I plant near Barstow (USA). With the introduction of expensive synthetic

Horst Michels; Robert Pitz-Paal

2007-01-01

206

Technical Note: Non-Darcy Mixed Convection from a Horizontal Surface with Variable Surface Heat Flux in a Porous Medium  

Microsoft Academic Search

This article investigates numerically the heat transfer characteristics of non-Darcy mixed convection over a horizontal flat plate with nonuniform surface heat flux in a porous medium. The surface heat flux is assumed to vary as a power of the axial coordinate measured from the leading edge of the plate. The entire regime of mixed convection (including the two limits of

Chien-Hsin Chen

1996-01-01

207

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

208

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

SciTech Connect

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

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

2009-12-15

209

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. Würdemann

2009-01-01

210

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

Ömer Çomakli; Mahmut Bayramo?lu; Kamil Kaygusuz

1996-01-01

211

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

Microsoft Academic Search

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

Klemens Schwarzer; Maria Eugênia Vieira da Silva

2003-01-01

212

Gas hydrate cool storage system  

Microsoft Academic Search

The invention presented relates to the development of a process utilizing a gas hydrate as a cool storage medium for alleviating electric load demands during peak usage periods. Several objectives of the invention are mentioned concerning the formation of the gas hydrate as storage material in a thermal energy storage system within a heat pump cycle system. The gas hydrate

M. P. Ternes; R. J. Kedl

1984-01-01

213

Natural element method for radiative heat transfer in a semitransparent medium with irregular geometries  

SciTech Connect

This paper develops a numerical solution to the radiative heat transfer problem coupled with conduction in an absorbing, emitting and isotropically scattering medium with the irregular geometries using the natural element method (NEM). The walls of the enclosures, having temperature and mixed boundary conditions, are considered to be opaque, diffuse as well as gray. The NEM as a meshless method is a new numerical scheme in the field of computational mechanics. Different from most of other meshless methods such as element-free Galerkin method or those based on radial basis functions, the shape functions used in NEM are constructed by the natural neighbor interpolations, which are strictly interpolant and the essential boundary conditions can be imposed directly. The natural element solutions in dealing with the coupled heat transfer problem for the mixed boundary conditions have been validated by comparison with those from Monte Carlo method (MCM) generated by the authors. For the validation of the NEM solution to radiative heat transfer in the semicircular medium with an inner circle, the results by NEM have been compared with those reported in the literatures. For pure radiative transfer, the upwind scheme is employed to overcome the oscillatory behavior of the solutions in some conditions. The steady state and transient heat transfer problem combined with radiation and conduction in the semicircular enclosure with an inner circle are studied. Effects of various parameters such as the extinction coefficient, the scattering albedo, the conduction–radiation parameter and the boundary emissivity are analyzed on the radiative and conductive heat fluxes and transient temperature distributions.

Zhang, Yong [School of Energy Science and Engineering, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001 (China)] [School of Energy Science and Engineering, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001 (China); Yi, Hong-Liang, E-mail: yihongliang@hit.edu.cn [School of Energy Science and Engineering, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001 (China)] [School of Energy Science and Engineering, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001 (China); Tan, He-Ping, E-mail: tanheping@hit.edu.cn [School of Energy Science and Engineering, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001 (China)] [School of Energy Science and Engineering, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001 (China)

2013-05-15

214

The DRESOR method for radiative heat transfer in semitransparent graded index cylindrical medium  

NASA Astrophysics Data System (ADS)

During a numerical analysis of radiative transfer in some cylindrical optical thermal analysis and thermal design, applying a cylindrical coordinate system would be much more convenient and precise than that using a Cartesian coordinate system. In this paper, the DRESOR method under a cylindrical coordinate system is proposed to address radiative transfer in a semitransparent graded index cylindrical medium. The dimensionless incident radiation and net radiative heat flux are obtained using the DRESOR method. The accuracy and validity of the proposed method is verified by comparison with other techniques. The effects of isotropic scattering albedo and graded index on radiative transfer are also considered. Additionally, the high directional radiative intensity information is obtained to show the performance of the DRESOR method. It shows that the DRESOR method is an effective technique to address the radiative transfer problem in the graded index cylindrical medium with complex surface temperature characteristics.

Cheng, Qiang; Zhang, Xian; Huang, Zhifeng; Wang, Zhichao; Zhou, Huaichun

2014-08-01

215

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

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

216

Solar energy storage via a closed-loop chemical heat pipe  

Microsoft Academic Search

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

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

1993-01-01

217

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

218

Evaluation of bone marrow-derived mesenchymal stem cells after cryopreservation and hypothermic storage in clinically safe medium.  

PubMed

Achievements in tissue engineering using mesenchymal stem cells (MSC) demand a clinically acceptable "off-the-shelf" cell therapy product. Efficacy of cryopreservation of human bone marrow-derived MSC in clinically safe, animal product-free medium containing 2%, 5%, and 10% dimethyl sulfoxide (DMSO) was evaluated by measuring cell recovery, viability, apoptosis, proliferation rate, expression of a broad panel of MSC markers, and osteogenic differentiation. Rate-controlled freezing in CryoStor media was performed in a programmable cell freezer. About 95% of frozen cells were recovered as live cells after freezing in CryoStor solutions with 5% and 10% DMSO followed by storage in liquid nitrogen for 1 month. Cell recovery after 5 months storage was 72% and 80% for 5% and 10% DMSO, respectively. Measurements of caspase 3 activity demonstrated that 15.5% and 12.8% of cells after 1 month and 18.3% and 12.9% of cells after 5 months storage in 5% and 10% DMSO, respectively, were apoptotic. Proliferation of MSC recovered after cryopreservation was measured during 2 weeks post-plating. Proliferation rate was not compromised and was even enhanced. Cryopreservation did not alter expression of MSC markers. Quantitative analysis of alkaline phosphatase (ALP) activity, ALP surface expression and Ca?? deposition in previously cryopreserved MSC and then differentiated for 3 weeks in osteogenic medium demonstrated the same degree of osteogenic differentiation as in unfrozen parallel cultures. Cell viability and functional parameters were analyzed in MSC after short-term storage at 4°C in HypoThermosol-FRS solution, also free of animal products. Hypothermic storage for 2 and 4 days resulted in about 100% and 85% cell recovery, respectively, less than 10% of apoptotic cells, and normal proliferation, marker expression, and osteogenic potential. Overall, our results demonstrate that human MSC could be successfully cryopreserved for banking and clinical applications and delivered to the bedside in clinically safe protective reagents. PMID:22196031

Ginis, Irene; Grinblat, Borislava; Shirvan, Mitchell H

2012-06-01

219

Magnetohydrodynamic non-Darcy mixed convection heat transfer from a vertical heated plate embedded in a porous medium with variable porosity  

Microsoft Academic Search

A numerical model is developed to study magnetohydrodynamics (MHD) mixed convection from a heated vertical plate embedded in a Newtonian fluid saturated sparsely packed porous medium by considering the variation of permeability, porosity and thermal conductivity. The boundary layer flow in the porous medium is governed by Forchheimer–Brinkman extended Darcy model. The conservation equations that govern the problem are reduced

Dulal Pal

2010-01-01

220

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

SciTech Connect

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

Steward, D. M.

2009-06-10

221

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.

222

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

Microsoft Academic Search

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

S. N. Mumah

2008-01-01

223

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

NASA Astrophysics Data System (ADS)

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

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

224

HEAT LOSSES FROM STORAGE TANKS: UP TO 5 TIMES HIGHER THAN CALCULATED  

Microsoft Academic Search

This is a summary of nearly 20-years-old research work at the former Swiss Federal Institute for Reactor Research, at Würenlingen, now the Paul Scherrer Institute. At the beginning of the eighties, solar-energy researchers performed systematic measurements of the long-term heat balance of solar heating systems. They became shocked by the results: heat storage tanks lost up to five times more

J.-M. Suter

225

Direct-contact heat exchange-storage tank in solar houses  

Microsoft Academic Search

A pilot plant direct-contact-heat-exchanger-storage-system has been tested with three collector liquids. These liquids were heavier than water and not soluble in water. Heat transfer and fluid dynamics were studied as these liquids streamed through a perforated plate at the top of the unit and passed down through a column of water. A full-scale direct-contact heat exchanger has been constructed and

W. Loss

1978-01-01

226

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

227

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

PubMed

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

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

2010-01-01

228

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

Microsoft Academic Search

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

M. P. Ternes

1985-01-01

229

Nano-technologies for head-medium interface in magnetic disk storage  

Microsoft Academic Search

Nano-technologies used in head-medium interfaces for magnetic disk drives are presented. To allow for an increase in bit density, head-to-medium spacing has to be minimized. Recently, the spacing has reduced to 40-50 nm. Such an ultimately small spacing could be realized by nano-technologies wherein the dimensions and physical quantities are required to be controlled to the nanometer scale. First, a

Y. Mitsuya

1997-01-01

230

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

SciTech Connect

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

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

1986-01-01

231

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

232

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

Microsoft Academic Search

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

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

2010-01-01

233

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

PubMed

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

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

2010-07-01

234

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

235

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

236

Numerical heat transfer study in a scattering, absorbing and emitting semi-transparent porous medium in a cylindrical enclosure  

NASA Astrophysics Data System (ADS)

In this paper, heat transfer problem through a semi-transparent porous medium in a cylindrical enclosure is investigated. The governing equations for this problem and the boundary conditions are non-linear differential equations depending on the dimensionless radial coordinate, Planck number N, scattering albedo ?, walls emissivity and thermal conductivity ratio kr. The set of differential equations are solved by a numerical technique taken from the IMSL MATH/LIBRARY. Various results are obtained for the dimensionless temperature profiles in the solid and fluid phases and the radiative heat flux. The effects of some radiative properties of the medium on the heat transfer rate are examined.

Timoumi, M.; Chérif, B.; Sifaoui, M. S.

2005-12-01

237

Basic Research on a Latent Heat Thermal Energy Storage by Direct Contact Melting and Solidification  

NASA Astrophysics Data System (ADS)

A basic experimental research on a latent heat thermal energy storage system, utilizing a simple and effective heat exchange mechanism by a direct contact between the phase change material (PCM) and the heat transfer fluid (HTF) , was shown. In this report, authors proposed the direct contact latent heat thermal energy storage system using industrial paraffin and n-Eicosane as the PCM, and using water as the HTF. The observations were performed concerning the HTF separation from the solid PCM in the solidification process (heat discharging process), and concerning the water pass formation within the solid PCM. Then, it was confirmed that the system worked effectively by using n-Eicosane as the PCM. And authors discussed the mechanism of direct contact solidification process from experimental results.

Saito, Akihiro; Saito, Akio; Utaka, Yoshio; Okuda, Kenichi; Katayama, Kozo

238

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

239

A complex but accurate correlation for predicting critical heat flux in a round tube for low and medium pressures under circumferentially non-uniform heating conditions  

Microsoft Academic Search

This paper presents an empirical correlation for predicting the critical heat flux (CHF) of vertical, upward, steam–water flows in round tubes for low and medium pressures under circumferentially non-uniform heating conditions. This correlation is based on experiments carried out with test sections having an inner diameter of 22mm and heated lengths ranging from 1.8 to 3.5m. The ratios between the

A. Olekhnovitch; J. Sun; A. Teyssedou

2008-01-01

240

Microwave heating to prevent deterioration of cottonseed during storage  

Microsoft Academic Search

Fuzzy cottonseed samples of 14.5% moisture and <1.0% free fatty acids (FFA) contents heated in a conventional, home-style\\u000a microwave oven at 700W and 2450 MHz for intervals up to 2.0 min. The 2.0-min treatment reduced the moisture content to 13.1%.\\u000a Examination of the seed immediately after microwave heating (MWH) indicated no differences in the proteins or in the quality\\u000a or

E. J. Conkerton; G. R. Schneider; J. M. Bland; W. R. Goynes

1991-01-01

241

High heat-load absorbers for the APS storage ring  

SciTech Connect

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

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

2000-07-21

242

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

SciTech Connect

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

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

1994-02-01

243

SEVESEM Systems: Heat Pumps with Incorporated Energy Storage Systems.  

National Technical Information Service (NTIS)

The concept of an absorption heat pump is generalized by considering it as a thermal transformer with a primary circuit, a cascade of multiple Vaporizers-Condensers-Separators (abbreviated VACOSEP) and a second circuit, a cascade of multiple Vaporizers-Co...

P. Le Goff

1982-01-01

244

Numerical modeling of coupled thermal chemical reactive transport: simulation of a heat storage system  

NASA Astrophysics Data System (ADS)

As a carbon-free energy supply technology, the operation time and final energy output of thermal solar power plants can be greatly extended if efficient thermal storage systems are applied. One of the proposed design of such system is to utilize reversible thermochemical reactions and its embedded reaction enthalpy, e.g. the Ca(OH)2/CaO hydration circle, in a fixed-bed gas-solid reactor (Schaube et al. 2011) The modeling of such a storage system involves multiple strongly-coupled physical and chemical processes. Seepage velocity is calculated by the nonlinear Forchheimer law. Gas phase density and viscosity are temperature, pressure and composition dependent. Also, heat transfer between gas and solid phases is largely influenced by the exothermal heat produced by the hydration of calcium oxide. Numerical solution of four governing PDEs include the mass balance, reactive transport, heat balance equations for gas and solid phases, which are implemented into the open source scientific software OpenGeoSys in a monolithic way. Based on it, a 2D numerical model, considering the boundary heat loss of the system, was set up to simulate the energy-storage and release circle. The high performance computing techniques were employed in two stages. First, the dynamic behavior of the heat storage system is simulated on a parallel platform. Second, a large number of processors are employed to perform sensitivity analysis, whereas the reaction rates and efficiency factor of heat transfer are parameterized so that the measured and simulated temperature profile fit with each other. The model showed that heat transfer coefficient between solid and gas phase, grain size of the filling material will influence the final performance greatly. By varying these factors, the calibrated model will be further applied to optimize the design of such energy storage system.

Shao, H.; Watanabe, N.; Singh, A. K.; Nagel, T.; Linder, M.; Woerner, A.; Kolditz, O.

2012-12-01

245

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

SciTech Connect

Vertically integrated diabatic heating rate estimates (H) calculated from 32 months of European Centre for Medium-Range Weather Forecasts daily analyses (May 1985-December 1987) are determined as residuals of the thermodyanmic equation in pressure coordinates. Values for Global, 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 for (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 El Nino-Southern Oscillation signal.

Christy, J.R. (Univ. of Alabama, Huntsville (USA))

1991-03-20

246

Two-tank working gas storage system for heat engine  

DOEpatents

A two-tank working gas supply and pump-down system is coupled to a hot gas engine, such as a Stirling engine. The system has a power control valve for admitting the working gas to the engine when increased power is needed, and for releasing the working gas from the engine when engine power is to be decreased. A compressor pumps the working gas that is released from the engine. Two storage vessels or tanks are provided, one for storing the working gas at a modest pressure (i.e., half maximum pressure), and another for storing the working gas at a higher pressure (i.e., about full engine pressure). Solenoid valves are associated with the gas line to each of the storage vessels, and are selectively actuated to couple the vessels one at a time to the compressor during pumpdown to fill the high-pressure vessel with working gas at high pressure and then to fill the low-pressure vessel with the gas at low pressure. When more power is needed, the solenoid valves first supply the low-pressure gas from the low-pressure vessel to the engine and then supply the high-pressure gas from the high-pressure vessel. The solenoid valves each act as a check-valve when unactuated, and as an open valve when actuated.

Hindes, Clyde J. (Troy, NY)

1987-01-01

247

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

PubMed

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

Silla, Aimee J

2013-01-01

248

Electrochemical hydrogen storage behaviors of CVD, AD and LA grown carbon nanotubes in KOH medium  

Microsoft Academic Search

Carbon nanotubes (CNTs) were synthesized catalytically by both chemical vapor deposition (CVD) method in C2H2\\/H2 atmosphere at 600°C and arc-discharge (AD) method under helium atmosphere. The structure and morphology of CNTs was determined employing scanning electron microscopy (SEM) and FT-Raman spectroscopy. Hydrogen storage capacities were electrochemically measured for undoped and alkali metal (Li, Na and K) doped CVD, AD and

A. K. M. Fazle Kibria; Y. H. Mo; K. S. Park; K. S. Nahm; M. H. Yun

2001-01-01

249

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

250

Economic evaluation of latent heat thermal energy storage using embedded thermosyphons for concentrating solar power applications  

Microsoft Academic Search

An economic evaluation of a latent heat thermal energy storage (LHTES) system for large scale concentrating solar power (CSP) applications is conducted. The concept of embedding gravity-assisted wickless heat pipes (thermosyphons) within a commercial-scale LHTES system is explored through use of a thermal network model. A new design is proposed for charging and discharging a large-scale LHTES system. The size

Christopher W. Robak; Theodore L. Bergman; Amir Faghri

2011-01-01

251

The effect of impurities on the melting temperature and the heat of fusion of latent heat storage materials  

NASA Astrophysics Data System (ADS)

Thermophysical properties of four normal paraffins (tetradecane, hexadecane, octadecane, eicosane) and three fatty acids (lauric acid, palmitic acid, stearic acid) were determined experimentally using a modified differential-thermoanalysis technique. For calibration of the measuring device, literature data in the temperature range from 5 to 70°C of six of these substances of at least 99% purity were used. Melting temperature, heat of fusion, and specific heat of a number of these “pure” and “technically pure” organic compounds were measured and compared to determine the effect of impurities and to give values of the application range of the properties required for the construction of thermal storage equipment.

Sohns, J.; Seifert, B.; Hahne, E.

1981-03-01

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

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

254

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

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

255

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

National Technical Information Service (NTIS)

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

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

1976-01-01

256

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

257

DYNAMICS OF WATER TRANSPORT AND STORAGE IN CONIFERS STUDIED WITH DEUTERIUM AND HEAT TRACING TECHNIQUES  

EPA Science Inventory

The volume and complexity of their vascular systems make the dynamics of long-distance water transport difficult to study. We used heat and deuterated water (D2O) as tracers to characterize whole-tree water transport and storage properties in individual trees belonging to the co...

258

Integrated Heat Pipe-Thermal Storage Design for a Solar Receiver.  

National Technical Information Service (NTIS)

Light-weight heat pipe wall elements that incorporate a thermal storage subassembly within the vapor space are being developed as part of the Organic Rankine Cycle Solar Dynamic Power Systems (ORC-SDPS) receiver for the space station application. The oper...

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

1986-01-01

259

Dynamics of water transport and storage in conifers studied with deuterium and heat tracing techniques  

Microsoft Academic Search

The volume and complexity of their vascular systems make the dynamics of long-distance water transport in large trees difficult to study. We used heat and deuterated water (D 20) as tracers to characterize whole-tree water transport and storage properties in individual trees belonging to the coniferous species Pseudotsuga menziesii (Mirb.) Franco and Tsuga heterophylla (Raf.) Sarg. The trees used in

F. C. MEINZER; J. R. BROOKS; J.-C. DOMEC; B. L. GARTNER; J. M. WARREN; D. R. WOODRUFF; K. BIBLE; D. C. SHAW

2006-01-01

260

Heat Storage in Urban Areas: Local-Scale Observations and Evaluation of a Simple Model  

Microsoft Academic Search

The flux density of sensible heat to or from storage in the physical mass of the city is determined for seven cities (Chicago, Illinois; Los Angeles, California; Mexico City, Distrito Federal; Miami, Florida; Sacramento, California; Tucson, Arizona; and Vancouver, British Columbia) in North America across a 308 latitudinal range. These cities have a variety of synoptic-scale climates and surface cover

C. S. B. Grimmond; T. R. Oke

1999-01-01

261

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

Microsoft Academic Search

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

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

2005-01-01

262

Experimental investigation on the use of water-phase change material storage in conventional solar water heating systems  

Microsoft Academic Search

This paper presents an experimental investigation of the performance of water-phase change material (PCM) storage for use with conventional solar water heating systems. Paraffin wax contained in small cylindrical aluminum containers is used as the PCM. The containers are packed in a commercially available, cylindrical hot water storage tank on two levels. The PCM storage advantage is firstly demonstrated under

I. Al-Hinti; A. Al-Ghandoor; A. Maaly; Z. Al-Khateeb

2009-01-01

263

Experimental investigation on the use of water-phase change material storage in conventional solar water heating systems  

Microsoft Academic Search

This paper presents an experimental investigation of the performance of water-phase change material (PCM) storage for use with conventional solar water heating systems. Paraffin wax contained in small cylindrical aluminum containers is used as the PCM. The containers are packed in a commercially available, cylindrical hot water storage tank on two levels. The PCM storage advantage is firstly demonstrated under

I. Al-Hinti; A. Al-Ghandoor; A. Maaly; I. Abu Naqeera; Z. Al-Khateeb; O. Al-Sheikh

2010-01-01

264

Considerations and measurements of latent-heat-storage salts for secondary thermal battery applications  

NASA Astrophysics Data System (ADS)

Given its potential benefits, the practicality of using a latent heat-storage material as the basis for a passive thermal management system is being assessed by Chloride Silent Power Ltd. (CSPL) with technical assistance from Beta Power, Inc. and Sandia National Laboratories (SNL). Based on the experience gained in large-scale solar energy storage programs, fused salts were selected as the primary candidates for the heat-storage material. The initial phase of this assessment was directed to an EV battery being designed at CSPL for the ETX-II program. Specific tasks included the identification and characterization of potential fused salts, a determination of placement options for the salts within the battery, and an assessment of the ultimate benefit to the battery system. The results obtained to date for each of these tasks are presented in this paper.

Koenig, A. A.; Braithwaite, J. W.; Armijo, J. R.

1988-05-01

265

Three-dimensional analysis for liquid hydrogen in a cryogenic storage tank with heat pipe–pump system  

Microsoft Academic Search

This paper presents a study on fluid flow and heat transfer of liquid hydrogen in a zero boil-off cryogenic storage tank in a microgravity environment. The storage tank is equipped with an active cooling system consisting of a heat pipe and a pump–nozzle unit. The pump collects cryogen at its inlet and discharges it through its nozzle onto the evaporator

Son H. Ho; Muhammad M. Rahman

2008-01-01

266

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

267

Thermo-chemical energy storage and heat transfer in a flow of hydrated magnesium sulfate  

NASA Astrophysics Data System (ADS)

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 thermo-chemical energy application. However, to investigate the thermal transport at the interface of the porous material and the salt, atomistic simulations are necessary. We employ molecular dynamics to simulate the heat transfer mechanism in a flow of hydrated magnesium sulfate impregnated into mesoporous silica and understand the role of interfacial thermal resistance on the charging temperature and total heat storage capacity of such salts.

Balasubramanian, Ganesh; Murad, Sohail; Puri, Ishwar K.

2009-11-01

268

Survival of microorganisms in a rock bed under conditions simulating solar heat storage  

SciTech Connect

A laboratory-scale unit containing about 360 kg of washed river gravel was designed to simulate the use of rocks for heat storage. The unit was operated under varying conditions of temperature, relative humidity, and the addition of volatile nutrients over a 4-month period. Effluent air and rock surfaces were monitored for the presence of microorganisms. After 2 weeks, virtually no microorganisms were detected in the effluent air except when dry soil or compost was added as the inoculum. A small number of heat-resistant bacteria, but no fungi, were found to survive on the rock surfaces. Microbial colonization of rock beds used for solar heat storage does not appear likely under routine operation.

Zervins, A. (Westinghouse Research and Development Center, Pittsburgh, PA); Babcock, M.; Stone, R.W.

1981-05-01

269

Role of winds in estimation of ocean heat storage anomaly using satellite data  

NASA Astrophysics Data System (ADS)

The heat storage anomaly of the upper ocean can be estimated using altimeter data, based on the thermal dynamics equation. In this study, we analyzed both nonthermal and thermal steric height measured by altimetry, and removed nonthermal steric height from altimeter measurements to calculate the heat storage anomaly from thermal steric height alone in the global oceans, but with a focus on the Pacific Ocean. After examining nonthermal steric height (salinity, waves, and wind), we believe that wind stress is a major component to the change in sea surface height. Blended TOPEX/Poseidon and ERS-1/2 altimeter 1° × 1° sea surface height anomaly from January 1993 to October 2000 were used to calculation of the heat storage anomaly. In addition, we used expendable bathythermograph (XBT) data to the global oceans to determine a reference heat storage, from which the altimeter estimation of the heat storage was compared. The wind stress curls, from scatterometer data obtained from January 1993 to October 2000, were used for analyzing the wind effects on sea surface height variation. The correlation coefficients between heat storage from altimeter data (HAlt') and that from the XBT (HXBT') are larger than 0.6 in the global oceans, except in the regions of 20°N in the eastern Pacific, the eastern tropical Pacific, the tropical Atlantic, and the western tropical Indian Ocean. The root mean square (RMS) of the differences (HAlt' - HXBT') has large values in the Gulf Stream and the Kuroshio Extension regions as well as the eastern and western tropical Pacific, and eastern Indian Ocean. The wind-induced sea surface height variation exhibits strong annual and interannual cycles, so the empirical orthogonal function (EOF) method was employed to extract the cycles. The annual cycle has two modes, whereas the interannual cycle is characterized by El Niño events. Wind stress can affect the estimation of the heat storage through mechanisms derived from quasi-geostrophic and barotropic theory. We calculated the correlation coefficient between the differences (HAlt' - HXBT') and wind stress curl. The result shows that El Niño Southern Oscillation (ENSO) related wind stress curl anomalies are responsible for estimating discrepancy in the regions west of South and North America and tropical oceans. The high correlation suggests that in these regions the barotropic and linear theory is the dynamic mechanism underlying the wind effects on heat storage estimation. Furthermore, we focus on baroclinic signal in sea level resulting from Ekman upwelling in the tropical oceans. The effect of wind-forcing has the most important role in sea level change during the 1997-1998 El Niño event. For instance, the heat storage anomaly (Q') due to the strong coastal upwelling off the west coast of Peru closely relates to sea surface temperature (SST), wind-forcing, remnant sea level height anomaly (??') after removing the contributions of the heat, salt, and waves to the sea level height, and Ekman depth (DEK). However, the Q' in the west coast of America and western Pacific warm pool areas did not closely relate to SST, wind-forcing, ??', and DEK.

Yan, Xiao-Hai; Pan, Jiayi; Jo, Young-Heon; He, Ming-Xia; Liu, W. Timothy; Jiang, Lide

2004-03-01

270

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

271

A portable direct-PV thermoelectric vaccine refrigerator with ice storage through heat pipes  

NASA Astrophysics Data System (ADS)

The objective of this research work was to develop a portable solar refrigeration system capable of maintaining vaccine temperatures between 2 °C and 8 °C. The main system under this study consisted of thermoelectric modules as cooling generators with latent heat energy storage (LHES) using water as cooling backup along with heat pipes as passive temperature controllers to avoid freezing the vaccines. The system was fabricated and tested. The results showed that the system can maintain the vaccine storage temperature at 2 °C and 8 °C under ambient temperature up to 30 °C with minimum power consumption of 30 Watt. The proposed heat pipes to maintain the vaccine storage temperature satisfied the design criteria. However, the energy consumption of the TEM was higher than anticipated. A small vapor compressor system was tested and shows promise to replace the TEM for cooling. Inserting the aluminum matrix in the ice chamber not only decreased the charging time but also decreased the discharging time since less phase change material was available for energy storage. Three models of the system were developed under different assumptions. The lumped model was adequate to predict the system performance during charging process. The other distributed models were able to predict the melting and cooling time more accurately than that of the lumped model and provided more detailed on the temperature distribution and change of the water phase in the ice chamber.

Jiajitsawat, Somchai

272

Analysis of combined conduction and radiation heat transfer in presence of participating medium by the development of hybrid method  

Microsoft Academic Search

The current study addresses the mathematical modeling aspects of coupled conductive and radiative heat transfer in the presence of absorbing, emitting and isotropic scattering gray medium within two-dimensional square enclosure. A blended method where the concepts of modified differential approximation employed by combining discrete ordinate method and spherical harmonics method, has been developed for modeling the radiative transport equation. The

S. K. Mahapatra; B. K. Dandapat; A. Sarkar

2006-01-01

273

Heat transfer by conduction and radiation in a one-dimensional planar medium using the differential approximation  

Microsoft Academic Search

The combined conduction and radiation heat transfer problem for a gray planar medium between two diffuse, isothermal infinite parallel plates is considered using the differential aproximation. e P-1 and P-3 spherical harmonics approximations for the intensity distribution are used. In addition, isotropic scattering and uniform volumetric generation terms are included. The governing energy equations developed using the P-1 and P-3

A. C. Ratzel; J. R. Howell

1981-01-01

274

Analysis of coupled conduction and radiation heat transfer in presence of participating medium- using a hybrid method  

Microsoft Academic Search

The current study addresses the mathematical modeling aspects of coupled conductive and radiative heat transfer in presence of absorbing, emitting and isotropic scattering gray medium within two-dimensional square enclosure. The walls of the enclosure are considered to be opaque, diffuse and gray. The enclosure comprised of isothermal vertical walls and insulated horizontal walls. A new hybrid method where the concepts

Sk Mahapatra; P. Nanda; A. Sarkar

2005-01-01

275

Effect of SEN structure on the mold level fluctuation and heat transfer for a medium thin slab caster  

Microsoft Academic Search

It is important to select suitable parameters of a submerged entry nozzle (SEN) for optimizing the flow and temperature patterns in a mold. The effect of SEN design on the mould level stability, meniscus steel flow velocity, and heat transfer of the mold of a medium thin slab caster was studied by means of 1:1 water modeling and industrial testing.

Heming Zhao; Xinhua Wang; Jiongming Zhang; Wanjun Wang

2008-01-01

276

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

Microsoft Academic Search

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

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

1975-01-01

277

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

NASA Astrophysics Data System (ADS)

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 Neubrandenburg (depth: 1250 m), a typical site for saline fluids in the North German Basin. The seasonal alternation in charge and discharge mode enabled sampling the warm (75Ë? C) and the cold (45Ë? C) side of the geothermal doublet. The analyses focus on microbially induced corrosion on plant components and scaling resulting in filter and/or formation clogging. Microbiological analyses were carried out with fluid and solid phase samples by 16S rDNA based Single Strand Conformation Polymorphism (SSCP) fingerprinting. The analyses are utilized to evaluate the impact of microbial populations on such systems. The genetic fingerprinting revealed significant differences in the bacterial community structure between the warm and cold side of the heat storage. Since the geochemical analyses revealed no remarkable differences, the temperature might be crucial for the different community structures. At the warm side of the aquifer the identified bacteria are closely related to Variovorax and Sphingomonas. At the cold side of the heat storage sulphate reducing and fermentative bacteria were detected. These results correspond with locally observed iron sulphide precipitation and corrosion processes on plant components. Particularly the bacterial population of the cold side was studied over a period of two years. Thereby seasonal changes in the abundance of the identified bacteria, depending on the operational mode of the geothermal plant, were observed. After a malfunction in the pump system of the cold side of the heat storage changes in the bacterial population structure were recognized by SSCP fingerprinting techniques.

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

2009-04-01

278

Latent heat-of-fusion energy storage - Experiments on heat transfer from cylinders during melting  

Microsoft Academic Search

Melting from an array of three staggered, electrically heated cylinders imbedded in a paraffin (n-octadecane) has been studied. The shape of the melting front has been determined photographically, and the local heat transfer coefficients were measured using a shadowgraph technique. The experiments provide conclusive evidence of the important role played by natural convection on the timewise variation of the melt

A. G. Bathelt; R. Viskanta; W. Leidenfrost

1979-01-01

279

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

280

Oulun kalliolaempoevarasto. Osa 2. Laempoevaraston muutostoet sekae niiden kustannukset. (Rock cavern heat storage in Oulu. Part 2. The converting works and their costs).  

National Technical Information Service (NTIS)

This paper discusses the converting of a storage cavern for industrial petrol into heat storage. The cavern has a volume of 190 000 m(sup 3). It is situated in the Oulu works of Kemira Oy. The heat storage is planned for seasonal storage of process waste ...

J. Ritola

1990-01-01

281

Solar hot water heating system  

Microsoft Academic Search

A solar hot water heating system, utilizing preferably a gas-liquid, phase change medium in the collector, employs one heating and storage tank above the collector and a preheating and storage tank below the first tank and preferably also below the collector. A cold water source feeds the inlet of the preheating tank which has its outlet connected to the inlet

1981-01-01

282

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 100°C 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=5×10-13 m2 to k=5×10-11 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

283

Storage Stability of Lycopene in Tomato Juice Subjected to Combined Pressure-Heat Treatments  

PubMed Central

A study was conducted to characterize the storage stability of lycopene in hot-break tomato juice prepared from two different cultivars and processed by various pressure–heat combinations. Samples were subjected to pressure assisted thermal processing (PATP; 600 MPa, 100 °C, 10 min), high pressure processing (HPP; 700 MPa, 45 °C, 10 min), and thermal processing (TP; 0.1 MPa, 100 °C, 35 min). Processed samples were stored at 4, 25, and 37 °C for upto 52 weeks. HPP and PATP treatments significantly improved the extractability of lycopene over TP and control. All-trans lycopene was found to be fairly stable to isomerization during processing, and the cis isomer content of the control and processed juice did not differ significantly. During storage, lycopene degradation varied as a function of the cultivar, processing method, storage temperature, and time. This study shows that combined pressure–temperature treatments could be an attractive alternative to thermal sterilization for preserving tomato juice quality.

Gupta, Rockendra; Balasubramaniam, V. M.; Schwartz, Steven J.; Francis, David M.

2013-01-01

284

Ultrahigh-density phase-change data storage without the use of heating.  

PubMed

Non-volatile memories based on scanning probes offer very high data densities, but existing approaches require the probe to be heated, which increases the energy expenditure and complexity of fabrication. Here, we demonstrate the writing, reading and erasure of an ultrahigh-density array of nanoscopic indentations without heating either the scanning probe tip or the substrate. An atomic force microscope tip causes microphase transitions of the polystyrene-block-poly(n-pentyl methacrylate) of a block copolymer to occur at room temperature by application of pressure alone. We demonstrate a data storage density of 1 Tb in(-2), which is limited only by the size of the tip. This demonstration of a pressure-based phase-change memory at room temperature may expedite the development of next-generation ultrahigh-density data storage media. PMID:19893531

Jo, Ara; Joo, Wonchul; Jin, Won-Hyeog; Nam, Hyojin; Kim, Jin Kon

2009-11-01

285

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

SciTech Connect

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. Sundstrand Corporation is developing a ORC-SDPS candidate for the Space Station that uses toluene as the organic fluid and LiOH as the TES material. 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. 3 refs., 8 figs.

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

1987-01-01

286

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

287

Development of heat-storage building materials for passive-solar applications  

Microsoft Academic Search

A heat storage building material to be used for passive solar applications and general load leveling within building spaces was developed. Specifically, PCM-filled plastic panels are to be developed as wallboard and ceiling panels. Three PCMs (CaCl2, 6H2O; Na2SO4, 10H2O; LiNO3, 3H2O are to be evaluated for use in the double walled, hollow channeled plastic panels. Laboratory development of the

J. W. Fletcher

1982-01-01

288

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

289

Plant expression, lyophilisation and storage of HBV medium and large surface antigens for a prototype oral vaccine formulation.  

PubMed

Current immunisation programmes against hepatitis B virus (HBV) increasingly often involve novel tri-component vaccines containing-together with the small (S-HBsAg)-also medium and large surface antigens of HBV (M- and L-HBsAg). Plants producing all HBsAg proteins can be a source of components for a potential oral 'triple' anti-HBV vaccine. The objective of the presented research was to study the potential of M/L-HBsAg expression in leaf tissue and conditions of its processing for a prototype oral vaccine. Tobacco and lettuce carrying M- or L-HBsAg genes and resistant to the herbicide glufosinate were engineered and integration of the transgenes was verified by PCR and Southern hybridizations. M- and L-HBsAg expression was confirmed by Western blot and assayed by ELISA at the level of micrograms per g of fresh weight. The antigens displayed a common S domain and characteristic domains preS2 and preS1 and were assembled into virus-like particles (VLPs). Leaf tissues containing M- and L-HBsAg were lyophilised to produce a starting material of an orally administered vaccine formula. The antigens were distinctly sensitive to freeze-drying conditions and storage temperature, in the aspect of stability of S and preS domains and formation of multimeric particles. Efficiency of lyophilisation and storage depended also on the initial antigen content in plant tissue, yet M-HBsAg appeared to be approximately 1.5-2 times more stable than L-HBsAg. The results of the study provide indications concerning the preparation of two other constituents, next to S-HBsAg, for a plant-derived prototype oral tri-component vaccine against hepatitis B. PMID:22246107

Pniewski, Tomasz; Kapusta, Józef; Boci?g, Piotr; Kostrzak, Anna; Fedorowicz-Stro?ska, Olga; Czy?, Marcin; Gdula, Micha?; Krajewski, Pawe?; Wolko, Bogdan; P?ucienniczak, Andrzej

2012-03-01

290

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

291

Colony formation by sublethally heat-injured Zygosaccharomyces rouxii as affected by solutes in the recovery medium and procedure for sterilizing medium.  

PubMed Central

Recovery and colony formation by healthy and sublethally heat-injured cells of Zygosaccharomyces rouxii as influenced by the procedure for sterilizing recovery media (YM agar [YMA], wort agar, cornmeal agar, and oatmeal agar) were investigated. Media were supplemented with various concentrations of glucose, sucrose, glycerol, or sorbitol and sterilized by autoclaving (110 degrees C, 15 min) and by repeated treatment with steam (100 degrees C). An increase in sensitivity was observed when heat-injured cells were plated on glucose-supplemented YMA at an aw of 0.880 compared with aws of 0.933 and 0.998. Colonies which developed from unheated and heated cells on YMA at aws of 0.998 and 0.933 generally exceeded 0.5 mm in diameter within 3.5 to 4 days of incubation at 25 degrees C, whereas colonies formed on YMA at an aw of 0.880 typically did not exceed 0.5 mm in diameter until after 5.5 to 6.5 days of incubation. The number of colonies exceeding 0.5 mm in diameter which were formed by heat-injured cells on YMA at an aw of 0.880 was 2 to 3 logs less than the total number of colonies detected, i.e., on YMA at an aw of 0.933 and using no limits of exclusion based on colony diameter. A substantial portion of cells which survived heat treatment were sublethally injured as evidenced by increased sensitivity to a suboptimum aw (0.880). In no instance was recovery of Z. rouxii significantly affected by medium sterilization procedure when glucose or sorbitol was used as the aw-suppressing solute.(ABSTRACT TRUNCATED AT 250 WORDS)

Golden, D A; Beuchat, L R

1990-01-01

292

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

DOEpatents

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

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

1981-04-21

293

Gas hydrate cool storage system  

DOEpatents

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

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

1984-09-12

294

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

295

Performance analysis of innovative collector fields for solar-electric plants, using air as heat transfer medium  

SciTech Connect

The production of electricity by thermodynamic conversion of the heat supplied by flat plate collectors has been tried many times. The use of air as heat transfer medium could allow a dramatic simplification of the collector field and a relevant reduction of thermal inertia. The paper discusses the characteristics of a system based on air collectors and ORC engine. Both multilayer inflated plastic sheet collectors and vacuum tubes collectors are proposed as suitable solutions. The field fan power consumption is optimized jointly with the power cycle evaporator design. Both the envisaged solutions are investigated on the point of view of overall cost/performance ratio.

De Marchi Desenzani, P.; Gaia, M.

1984-08-01

296

Development and testing of thermal-energy-storage modules for use in active solar heating and cooling systems. Final report  

SciTech Connect

Additional development work on thermal-energy-storage modules for use with active solar heating and cooling systems is summarized. Performance testing, problems, and recommendations are discussed. Installation, operation, and maintenance instructions are included. (MHR)

Parker, J.C.

1981-04-01

297

A comparative performance rating for an integrated solar collector\\/storage vessel with inner sleeves to increase heat retention  

Microsoft Academic Search

Integral Collector\\/Storage (ICS) solar water heating systems suffer substantial heat loss during periods of low insolation or at night. Methods to reduce aperture heat loss include moveable insulated lids\\/shutters, transparent insulating glazing materials and selective glazing\\/absorber coatings. All of these approaches involve trade-offs with reduction in performance and\\/or an increase in cost. A novel ICS vessel design to mitigate heat

M Smyth; P. C Eames; B Norton

1999-01-01

298

Evaluation of Heat Transfer Coefficient During Drying of Typical Municipal Solid Waste Matrices with Significant Shrinkage at Medium Temperature  

Microsoft Academic Search

High-moisture municipal solid waste leads to lower heat value, lower combustion efficiency, and frequent and serious erosion during incinerating. Municipal solid waste should be dried before being efficiently incinerated. The purpose of this work is to carry out experimental study and simulation on characteristics of moisture migration of municipal solid waste matrices at medium temperature (100°C–200°C) in a muffle furnace.

M. Q. Chen; L. Jia; T. T. Zhang

2012-01-01

299

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

300

A Numerical Study on Heat Transfer of High Efficient Solar Flat-Plate Collectors with Energy Storage  

Microsoft Academic Search

The integrated solar collector is considered to be a promising direction for increasing the economic feasibility of low-temperature solar systems for heating water in domestic and industrial applications. Phase change material (paraffin) energy storage can be used in solar water heaters. The paraffin-integrated solar collector eliminates the need of conventional storage tanks, thus reducing cost and space. But a negative

Zhenqian Chen; Mingwei Gu; Donghua Peng; Changhai Peng; Zhishen Wu

2010-01-01

301

Conceptual Design Selection and Development of a Latent-Heat Thermal-Energy-Storage Subsystem for a Saturated-Steam Solar Receiver and Load.  

National Technical Information Service (NTIS)

The following latent heat storage concepts are described and evaluated in comparison with each other and with an oil/rock sensible heat storage system: (1) passive tube intensive (shell-and-tube heat exchanger) with and without heat transfer enhanced by f...

1981-01-01

302

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

SciTech Connect

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

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

1987-07-01

303

Energy storage using phase-change materials for active solar heating and cooling: an evaluation of future research and development directions  

SciTech Connect

The current state of the art and commercial potential of active solar heating and cooling systems for buildings, and, in particular, the use of thermal energy storage with these systems are assessed. This assessment is used to determine the need for advanced latent heat storage subsystems in these applications and priorities for their development. Latent storage subsystems are advantageous in applications where their compactness may be exploited. These subsystems could facilitate storage in retrofit applications in which storage would be physically impossible otherwise.

Borkowski, R.J.; Stovall, T.K.; Kedl, R.J.; Tomlinson, J.J.

1982-04-01

304

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

305

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

Microsoft Academic Search

This report describes the decay heat, heat transfer, and shielding analyses conducted in support of performance testing of a Ridhihalgh, Eggers and Associates REA 2033 boiling water reactor (BWR) spent fuel storage cask. The cask testing program was conducted for the US Department of Energy (DOE) Commercial Spent Fuel Management Program by the Pacific Northwest Laboratory (PNL) and by General

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

2011-01-01

306

Heat treatment of colostrum increases immunoglobulin G absorption efficiency in high-, medium-, and low-quality colostrum.  

PubMed

Previous studies with heat-treated colostrum fed to neonatal calves have consistently used average-quality colostrum. Studies have not compared colostrum across a range of immunoglobulin levels. This study was conducted to investigate IgG absorption in neonatal dairy calves using colostrum of various qualities. Colostrum from the Pennsylvania State University dairy was collected over 2 yr and sorted into high, medium, and low quality based on colostrometer measurement. Colostrum within each category was pooled to create 3 unique, uniform batches. Half of each batch was frozen to be fed without heat treatment. The second half of each batch was heat treated at 60°C for 30min. This process was conducted in September 2011, and repeated in June 2012. Colostrum treatments were analyzed for standard plate count, coliforms, noncoliform gram-negative bacteria, and total IgG concentration. Plasma samples were collected from 145 calves 48h after birth and analyzed for IgG1, IgG2, total protein, and hematocrit. Colostrum quality (high, medium, or low), treatment (unheated or heat treated), and their interactions were analyzed as fixed effects, with year included as a random effect. Heat treatment significantly reduced all types of bacteria and IgG concentration. Plasma IgG concentration at 48h increased linearly with the concentration of IgG in the colostrum that was consumed. Heat treatment of colostrum increased plasma IgG concentration by 18.4% and apparent efficiency of absorption by 21.0%. Results of this study suggest that heat treatment of colostrum containing approximately 50 to 100mg IgG/mL increases absorption of IgG from colostrum. PMID:24508433

Gelsinger, S L; Gray, S M; Jones, C M; Heinrichs, A J

2014-04-01

307

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

PubMed

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

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

2013-05-15

308

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

SciTech Connect

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

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

1988-04-01

309

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

NASA Technical Reports Server (NTRS)

A thermal analysis was performed of a thermal energy storage canister of a type suggested for use in a solar receiver for an orbiting Brayton cycle power system. Energy storage for the eclipse portion of the cycle is provided by the latent heat of a eutectic mixture of LiF and CaF2 contained in the canister. The chief motivation for the study is the prediction of vapor void effects on temperature profiles and the identification of possible differences between ground test data and projected behavior in microgravity. The first phase of this study is based on a two-dimensional, cylindrical coordinates model using an interim procedure for describing void behavor in 1-g and microgravity. The thermal analysis includes the effects of solidification front behavior, conduction in liquid/solid salt and canister materials, void growth and shrinkage, radiant heat transfer across the void, and convection in the melt due to Marangoni-induced flow and, in 1-g, flow due to density gradients. A number of significant differences between 1-g and o-g behavior were found. This resulted from differences in void location relative to the maximum heat flux and a significantly smaller effective conductance in 0-g due to the absence of gravity-induced convection.

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

1988-01-01

310

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

311

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

312

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

313

Inorganic compounds for passive solar energy storage: Solid-state dehydration materials and high specific heat materials  

NASA Astrophysics Data System (ADS)

Two classes of hydrated inorganic salts have been studied to assess their potential as materials for passive solar energy storage. The materials are part of the quaternary system CaO-Al2O3-SO3-H2O and related chemical systems, and the two classes are typified by ettringite, a trisubstituted salt, and Friedel's salt, a monosubstituted salt. The trisubstituted salts were studied for their possible application in latent heat storage, utilizing a low-temperature dehydration reaction, and both classes were studies for their application in sensible heat storage. In order to assess their potential for energy storage, the salts have been synthesized, characterized by several analytical techniques, and thermal properties measured. The dehydration data of that the trisubstituted salts vary somewhat with chemical composition, with the temperature of the onset of dehydration ranging from 6(0)C to 33(0)C, and enthalpy changes on dehydration ranging from 60 to 200 cal/g. Heat capacity is less variable with composition; values for the trisubstituted phases are 30 cal/g/(0)C and for the monosubstituted phases between 0.23 and 0.28 cal/g/(0)C. Preliminary experiments indicate that the dehydration is reversible, and suggest that the materials might have additional potential as solar desiccant materials. These thermal data demonstrate the trisubstituted salts have potential as latent heat storage materials, and that both classes of salts have potential as sensible heat storage materials.

Struble, L. J.; Brown, P. W.

1986-04-01

314

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

315

Failure analysis of a sodium heat pipe with integral lithium fluoride thermal energy storage  

NASA Astrophysics Data System (ADS)

A sodium, 321 stainless steel heat pipe with three filled Nb-1Zr tubes for thermal energy storage with 304 S.S. screen for wicking was thermal cycled to failure and then an analysis was performed to examine the failure. It was concluded that insufficient weld depth between an end cap and tube body permitted the propagation of a crack through a possible combination of thermal/corrosion failure, creep rupture of the end cap. A number of possible scenarios for the process following a leak are discussed.

Jacobson, D. L.; Soundararajan, P.

1985-09-01

316

Investigation on thermal properties of heat storage composites containing carbon fibers  

NASA Astrophysics Data System (ADS)

We prepared a series of thermal performance-enhanced heat storage composite phase change materials containing carbon fibers. It revealed that the composites have reduced both melting point and latent heat capacity with an increase in the mass fraction of the carbon fibers (CF) or mechano-chemical treated CF (M-CF). Composites have enhanced thermal conductivities compared to palmitic acid (PA), with the enhancement ratios increasing with the mass fraction of additives. M-CF/PA enhances more thermal conductivity than CF/PA does when they contain the same additives and are at the same temperature. Thermal conductivity enhancement of 0.5 wt. % M-CF/PA is 239.2% in liquid state, compared with PA.

Wang, Jifen; Xie, Huaqing; Xin, Zhong; Li, Yang; Yin, Chou

2011-11-01

317

Thermal energy storage material thermophysical property measurement and heat transfer impact  

NASA Technical Reports Server (NTRS)

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 latent heat of fusion), and density of each salt were measured for a temperature range of at least + or - 100 K of the measured melting point. Measurements were made with both reagent and commercial grades of each salt.

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

1976-01-01

318

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

319

Short-term storage of human spermatozoa in electrolyte-free medium without freezing maintains sperm chromatin integrity better than cryopreservation.  

PubMed

Previous attempts to maintain human spermatozoa without freezing were based on short-term storage in component-rich medium and led to fast decline in motility and increased incidence of chromosome breaks. Here we report a new method in which sperm are maintained without freezing in an electrolyte-free medium (EFM) composed of glucose and bovine serum albumin. Human sperm were stored in EFM or human tubal fluid medium (HTFM) or were cryopreserved, and their motility, viability, and DNA integrity were examined at different intervals. Cryopreservation led to significant decline in sperm motility and viability and induced DNA fragmentation. Sperm stored in EFM maintained motility and viability for up to 4 and 7 wk, respectively, much longer than sperm stored in HTFM (<2 and <4 wk, respectively). DNA integrity, assessed with comet assay, was also maintained significantly better in EFM than in HTFM. One-week storage in EFM yielded motility and viability similar to that of cryopreserved sperm, but DNA integrity was significantly higher, resembling that of fresh sperm. After several weeks of storage in EFM, sperm were able to activate oocytes, undergo chromatin remodeling, and form normal zygotic chromosomes after intracytoplasmic sperm injection. This study demonstrated that human spermatozoa can be stored in EFM without freezing for several weeks while maintaining motility, viability, and chromatin integrity and that 1-wk storage in EFM offers better protection of sperm DNA integrity than cryopreservation. Sperm storage in EFM may become a viable option for the physicians working in assisted reproduction technology clinics, which would avoid cryodamage. PMID:21593474

Riel, Jonathan M; Yamauchi, Yasuhiro; Huang, Thomas T F; Grove, John; Ward, Monika A

2011-09-01

320

Tree-shaped fluid flow and heat storage in a conducting solid  

NASA Astrophysics Data System (ADS)

This paper documents the time-dependent thermal interaction between a fluid stream configured as a plane tree of varying complexity embedded in a conducting solid with finite volume and insulated boundaries. The time scales of the convection-conduction phenomenon are identified. Two-dimensional and three-dimensional configurations are simulated numerically. The number of length scales of the tree architecture varies from one to four. The results show that the heat transfer density increases, and the time of approach to equilibrium decreases as the complexity of the tree designs increases. These results are then formulated in the classical notation of energy storage by sensible heating, which shows that the effective number of heat transfer units increases as the complexity of the tree design increases. The complexity of heat transfer designs in many applications is constrained by first cost and operating cost considerations. This work provides a fundamental basis for objective evaluation of cost and performance tradeoffs in thermal design of energy systems with complexity as an unconstrained parameter that can be actively varied over a broad range to determine the optimum system design.

Combelles, L.; Lorente, S.; Anderson, R.; Bejan, A.

2012-01-01

321

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

322

Nonlinear Dynamics of Turbulent Coronal Heating Mechanisms: Thermodynamics, Energy Storage and Release  

NASA Astrophysics Data System (ADS)

Thermodynamics of the magnetically confined solar corona are investigated with fully compressible three-dimensional magnetohydrodynamic simulations. Coronal loops field lines' footpoints are shuffled by space-filling homogeneous photospheric motions giving rise to turbulent nonlinear dynamics. Field-aligned current sheets continuously form and dissipate depositing energy at the small-scales where the heating occurs. Previous studies show that current sheets thickness is orders of magnitude smaller than current state of the art observational resolution (~700 km). Therefore to understand coronal heating and its observed properties we need to understand the thermodynamics of such a system where energy is deposited at unresolved small-scales. We show that at observationally sub-resolution scales temperature is highly structured and non-homogeneously distributed. In this multi-thermal highly dynamical system, hotter and cooler plasma strands are found one next to the other at sub-resolution scales, and only a fraction of the coronal mass and volume gets heated at each time. The basal coronal heating described above is characterized by a limited storage of magnetic energy and numerous small releases of energy, so-called nanoflares. Reduced magnetohydrodynamic simulations show that such system stores a considerably higher magnetic energy when localized photospheric motions are applied. Its dynamics, mechanisms of subsequent release of the stored energy in micro- or larger flares, and the impact on coronal dynamics will be discussed.

Einaudi, G.; Dahlburg, R.; Rappazzo, A. F.; Velli, M. M.

2012-12-01

323

Tree-Shaped Fluid Flow and Heat Storage in a Conducting Solid  

SciTech Connect

This paper documents the time-dependent thermal interaction between a fluid stream configured as a plane tree of varying complexity embedded in a conducting solid with finite volume and insulated boundaries. The time scales of the convection-conduction phenomenon are identified. Two-dimensional and three-dimensional configurations are simulated numerically. The number of length scales of the tree architecture varies from one to four. The results show that the heat transfer density increases, and the time of approach to equilibrium decreases as the complexity of the tree designs increases. These results are then formulated in the classical notation of energy storage by sensible heating, which shows that the effective number of heat transfer units increases as the complexity of the tree design increases. The complexity of heat transfer designs in many applications is constrained by first cost and operating cost considerations. This work provides a fundamental basis for objective evaluation of cost and performance tradeoffs in thermal design of energy systems with complexity as an unconstrained parameter that can be actively varied over a broad range to determine the optimum system design.

Combelles, L.; Lorente, S.; Anderson, R.; Bejan, A.

2012-01-01

324

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

325

Meshless approach for coupled radiative and conductive heat transfer in one-dimensional graded index medium  

NASA Astrophysics Data System (ADS)

A meshless local Petrov Galerkin (MLPG) approach is employed for solving the coupled radiative and conductive heat transfer in a one-dimensional slab with graded index media. The angular distribution term in discrete ordinate equation of radiative transfer within a one-dimensional graded index slab is discretized by a step scheme, and the meshless approach for radiative transfer is based on the discrete ordinate equation. A moving least-squares approximation is used to construct the shape function. Two particular test cases for coupled radiative and conductive heat transfer within a one-dimensional graded index slab are examined to verify this new approximate method. The temperatures and the radiative heat fluxes are obtained. The results are compared with the other benchmark approximate solutions. By comparison, the results show that the MLPG approach has a good accuracy in solving the coupled radiative and conductive heat transfer in one-dimensional graded index media.

Liu, L. H.; Tan, J. Y.; Li, B. X.

2006-09-01

326

Bottoming cycles for electric energy generation: Parametric investigation of available and innovative solutions for the exploitation of low and medium temperature heat sources  

Microsoft Academic Search

Many industrial processes and conventional fossil fuel energy production systems used in small-medium industries, such as internal combustion engines and gas turbines, provide low or medium temperature (i.e., 200–500°C) heat fluxes as a by-product, which are typically wasted in the environment. The possibility of exploiting this wasted heat, converting it into electric energy by means of different energy systems, is

M. Bianchi; A. De Pascale

2011-01-01

327

Heat and mass transfer in magneto-biofluid flow through a non-Darcian porous medium with Joule effect  

NASA Astrophysics Data System (ADS)

In the present study, a mathematical model for the hydromagnetic non-Newtonian biofluid flow in the non-Darcy porous medium with Joule effect is proposed. A uniform magnetic field acts perpendicularly to the porous surface. The governing nonlinear partial differential equations are transformed into linear ones which are solved numerically by applying the explicit finite difference method. The effects of various parameters, like Reynolds number and hydro-magnetic, Forchheimer, and Darcian parameters, Prandtl, Eckert, and Schmidt numbers, on the velocity, temperature, and concentration are presented graphically. The results of the study can find applications in surgical operations, industrial material processing, and various heat transfer processes.

Sharma, B. K.; Mishra, A.; Gupta, S.

2013-07-01

328

Measured performance of a solar augmented heat pump/chiller system with thermal storage in tanks of stratified water  

SciTech Connect

The performance of the heating and cooling system in a building designed to illustrate energy conservation, solar energy use and thermal storage for electric load management and energy conservation was monitored for a period of 20 months, beginning in January 1981. Solar energy was employed to augment the heating energy obtained by heat recovery using electric-driven reciprocating heat pump/chillers and an air-to-air heat exchanger. Solar energy was gathered by 289 m/sup 2/ (3110 ft/sup 2/) of evacuated tube collectors on the roof of the building, which has a gross floor area of 5330 m/sup 2/ (57,350 ft/sup 2/). The fractions of the total active heating load, including air-to-air heat recovery, supplied by solar energy for the one partial and one completed heating season for which results were obtained, were 50 and 42 percent, respectively. Stratified water tanks were used in the heating season to store excess solar energy and both heating and cooling capacity generated by the heat pump/chillers. During the cooling season, the tanks were used to store cooling capacity generated by the chillers. An economic analysis using the results for energy consumption obtained from this building indicated that the solar system was not economically attractive, despite its encouraging technical performance. Thermal storage for electric load management was attractive for moderate costs of capital.

Wildin, M.W.

1983-01-01

329

Transient radiative heat transfer from a sphere surrounded by a participating medium  

Microsoft Academic Search

Transient radiative cooling of a solid or liquid sphere in space, surrounded by a radiatively participating vapor cloud, is considered. A quasi-steady assumption is applied to the radiation transfer in the medium, with the unsteadiness being retained at the inner spherical boundary. The problem is solved by applying the third-order (P3) spherical harmonics approximation to the radiative transfer equation for

Y. Bayazitoglu; P. V. R. Suryanarayana

1989-01-01

330

Arbitrary-Order Spherical Harmonics Method for Radiative Heat Transfer in Semitransparent Medium  

Microsoft Academic Search

A radiative transfer model for a linearly or nonlinearly anisotropic scattering medium is developed. An arbitrary-order spherical harmonics method (PN-approximation) was presented to decompose the radiative transfer equation into a set of coupled partial differential equations which solved by the tridiagonal matrix method. By using PN-approximation formulation, the greenhouse effect from carbon dioxide on atmosphere temperature profile was simulated. The

Wang Yanming; Tan Heping

2009-01-01

331

Inhibitor of Clostridium perfringens Formed by Heating Sodium Nitrite in a Chemically Defined Medium  

PubMed Central

An inhibitor of Clostridium perfringens formed when low levels of nitrite were autoclaved with a defined chemical medium. A systematic study of the medium revealed that only amino acids and mineral salts were involved in the production of this inhibitor, which was proven to be a toxic compound formed from cysteine, ferrous sulfate, and sodium nitrite. The inhibitor was compared to several known compounds. S-nitrosocysteine inhibited the test organism, but would not form in the test system in amounts large enough to explain the observed inhibition. Roussin red salt was unstable in the test system and therefore was not the inhibitor. Roussin black salt, which was also inhibitory, could form in sufficient amounts to explain the inhibition. A complex of cysteine, iron, and nitrie oxide was detected in the autoclaved solution of cysteine, ferrous sulfate, and sodium nitrite; this cysteine complex did not appear to be inhibitory, however, at levels which could form in the autoclaved medium. The observed inhibition may have been due to the combined effects of sublethal concentrations of each compound.

Moran, Dennis M.; Tannenbaum, Steven R.; Archer, Michael C.

1975-01-01

332

The effect of a covert manipulation of ambient temperature on heat storage and voluntary exercise intensity.  

PubMed

The modulation of sub-maximal voluntary exercise intensity during heat stress has been suggested as a behavioral response to maintain homeostasis; however, the relationship between thermophysiological cues and the associated response remains unclear. Awareness of an environmental manipulation may influence anticipatory planning before the start of exercise, making it difficult to isolate the dynamic integration of thermophysiological afferents during exercise itself. The purpose of the present study was to examine the direct real-time relationship between thermophysiological afferents and the behavioral response of voluntary exercise intensity. Participants were tasked with cycling at a constant rating of perceived exertion while ambient temperature (T(a)) was covertly changed from 20 °C to 35 °C and then back to 20 °C at 20-minute intervals. Overall, power output (PO) and heat storage, quantified using repeated measures ANOVA, changed significantly over 20-minute intervals (135 ± 39 W, 133 ± 46 W, 120 ± 45 W; 52.35 ± 36.15 W·m(-2), 66.34 ± 22.02 W·m(-2), -66.53 ± 56.01 W·m(-2)). The synchronicity of PO fluctuations with changes in thermophysiological status was quantified using Auto-Regressive Integrated Moving Average (ARIMA) time series analysis. Fluctuations in PO were not synchronized in real time with changes in T(a); heat storage; rectal, skin, or mean body temperature; or sweat rate (stationary-r(2) ? 0.10 and Ljung-Box statistic > 0.05 for all variables). We conclude that, while the thermal environment affects physiological responses and voluntary power output while cycling at a constant perceived effort, the behavioral response of voluntary exercise intensity did not depend on a direct response to real-time integration of thermal afferent inputs. PMID:22226992

Hartley, Geoffrey L; Flouris, Andreas D; Plyley, Michael J; Cheung, Stephen S

2012-03-20

333

GEOMETRY, HEAT REMOVAL AND KINETICS SCOPING MODELS FOR HYDROGEN STORAGE SYSTEMS  

SciTech Connect

It is recognized that detailed models of proposed hydrogen storage systems are essential to gain insight into the complex processes occurring during the charging and discharging processes. Such insight is an invaluable asset for both assessing the viability of a particular system and/or for improving its design. The detailed models, however, require time to develop and run. Clearly, it is much more efficient to begin a modeling effort with a good system design and to progress from that point. To facilitate this approach, it is useful to have simplified models that can quickly estimate optimal loading and discharge kinetics, effective hydrogen capacities, system dimensions and heat removal requirements. Parameters obtained from these models can then be input to the detailed models to obtain an accurate assessment of system performance that includes more complete integration of the physical processes. This report describes three scoping models that assess preliminary system design prior to invoking a more detailed finite element analysis. The three models address the kinetics, the scaling and heat removal parameters of the system, respectively. The kinetics model is used to evaluate the effect of temperature and hydrogen pressure on the loading and discharge kinetics. As part of the kinetics calculations, the model also determines the mass of stored hydrogen per mass of hydride (in a particular reference form). As such, the model can determine the optimal loading and discharge rates for a particular hydride and the maximum achievable loading (over an infinite period of time). The kinetics model developed with the Mathcad{reg_sign} solver, runs in a mater of seconds and can quickly be used to identify the optimal temperature and pressure for either the loading or discharge processes. The geometry scoping model is used to calculate the size of the system, the optimal placement of heat transfer elements, and the gravimetric and volumetric capacities for a particular geometric configuration and hydride. This scoping model is developed in Microsoft Excel{reg_sign} and inputs the mass of hydrogen to be stored, mass of stored hydrogen to mass of hydride (from the kinetics model), component densities, etc. The heat removal scoping model is used to calculate coolant flowrates, pressure drops and temperature increases over the length of the cooling channels. The model also calculates the convection heat transfer coefficient required to remove the heat of reaction associated with hydrogen uptake. The heat removal model inputs dimensions and the mass of hydrogen to be stored directly from the geometry scoping model. Additionally, the model inputs the heats of reaction, the thermal properties of the coolant and the time required to charge the bed.

Hardy, B

2007-11-16

334

Effect of Viscous Dissipation and Thermal Radiation on Heat Transfer over a Non-Linearly Stretching Sheet Through Porous Medium  

NASA Astrophysics Data System (ADS)

In this present paper, we have discussed the effects of viscous dissipation and thermal radiation on heat transfer over a non-linear stretching sheet through a porous medium. Usual similarity transformations are considered to convert the non-linear partial differential equation of motion and heat transfer into ODE's. Solutions of motion and heat transfer are obtained by the Runge-Kutta integration scheme with most efficient shooting technique. The graphical results are presented to interpret various physical parameters of interest. It is found that the velocity profile decreases with an increase of the porous parameter asymptotically. The temperature field decreases with an increase in the parametric values of the Prandtl number and thermal radiation while with an increase in parameters of the Eckert number and porous parameter, the temperature field increases in both PST (power law surface temperature) and PHF (power law heat flux) cases. The numerical values of the non-dimensional wall temperature gradient and wall temperature are tabulated and discussed.

Nandeppanavar, M. M.; Siddalingappa, M. N.

2013-06-01

335

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

SciTech Connect

The purpose of this investigation was to develop a procurement specification for recuperative heat exchangers in Compressed Air Energy Storage Applications. Potential problem areas were identified and designs, operational guidelines, and a procurement specification were developed to minimize these problems. Interviews were conducted at existing recuperative gas turbine installations to identify the existing experience with recuperators. Thermal stress cracking, low temperature sulfuric acid corrosion, and structural vibrations were identified as the most common problems. A literature search was conducted to identify means to minimize the corrosion and vibrations. A finite element analysis of a tube to tubesheet joint for a shell-and-tube recuperator was performed to identify the impact of tubesheet thickness, weld types, materials, temperatures, construction details, and heat transfer coefficients on transient thermal stresses. From this analysis means to obtain acceptable cyclic life were identified. The results of this investigation indicate that a recuperator for a CAES plant can be designed and built at reasonable cost that will provide acceptable service life. The best life attained was estimated from analytic study to be thirty years. Ferritic steels provided longer life than austenitic due to both decreased corrosion rate and thermal stress. Design procedure, according to ASME Section VIII, Division 2 was recommended since more economical design for cyclic duty is possible. Vibration analysis was recommended for all recuperator final designs. Finally, a procurement specification was developed to enable both the purchaser and manufacturer to incorporate into a CAES plant a successfully operating and long-lived recuperative heat exchanger.

Lukas, H.; Montgomery, M.E.

1985-01-01

336

Convection driven by tidal and radiogenic heating in medium size icy satellites  

Microsoft Academic Search

Convection is one of the most important processes responsible for the formation of the surface features on many planetary bodies. Observations of some icy satellites indicate that the satellites’ surfaces are modified due to the internally driven tectonic activity. The tidal heating could be an important source of energy responsible for such internal activity. This suggestion is supported by the

L. Czechowski; J. Leliwa-Kopystynski

2005-01-01

337

User Manual for AQUASTOR: a Computer Model for Cost Analysis of Aquifer Thermal-Energy Storage Oupled with District-Heating or -Cooling Systems. Volume II. Appendices.  

National Technical Information Service (NTIS)

A computer model called AQUASTOR was developed for calculating the cost of district heating (cooling) using thermal energy supplied by an aquifer thermal energy storage (ATES) system. the AQUASTOR Model can simulate ATES district heating systems using sto...

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

1982-01-01

338

Computational approaches to aspect-ratio-dependent upper bounds and heat flux in porous medium convection  

NASA Astrophysics Data System (ADS)

Direct numerical simulation (DNS) has shown that Rayleigh-Bénard convection in a fluid-saturated porous medium self-organizes into narrowly spaced plumes at (ostensibly) asymptotically high values of the Rayleigh number Ra. In this Letter a combination of DNS and upper bound theory is used to investigate the dependence of the Nusselt number Nu on the domain aspect ratio L at large Ra. A novel algorithm is introduced to solve the optimization problems arising from the upper bound analysis, allowing for the best available bounds to be extended up to Ra?2.65×104. The dependence of the bounds on L(Ra) is explored and a “minimal flow unit” is identified.

Wen, Baole; Chini, Gregory P.; Dianati, Navid; Doering, Charles R.

2013-12-01

339

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

340

Lie group analysis and numerical solutions for non-Newtonian nanofluid flow in a porous medium with internal heat generation  

NASA Astrophysics Data System (ADS)

A mathematical model is presented and analysed for steady two-dimensional non-isothermal boundary layer flow from a heated horizontal surface which is embedded in a porous medium saturated with a non-Newtonian power-law nanofluid. It is assumed that the wall temperature and nanoparticle volume fraction vary nonlinearly with the axial distance. By applying appropriate group transformations, the governing transport equations are reduced to a system of coupled, nonlinear ordinary differential equations with associated boundary conditions. The reduced equations are then solved numerically using the Runge-Kutta-Fehlberg fourth-fifth-order numerical method with Maple 13 software. The effects of several thermophysical parameters including rheological power-law index, non-isothermal index, Lewis number, Brownian motion parameter, thermophoresis parameter, buoyancy ratio and internal heat generation/absorption parameter on the non-dimensional velocity, temperature, nanoparticle volume fraction (concentration) and also on the friction factor, heat and mass transfer rates are investigated. A comparison of the present results with the existing published results shows excellent agreement, verifying the accuracy of the present numerical code. The study finds applications in nano biopolymeric manufacturing processes and also thermal enhancement of energy systems employing rheological working fluids.

Jashim Uddin, Md; Yusoff, N. H. Md; Bég, O. Anwar; Izani Ismail, Ahamd

2013-02-01

341

Effect of calcium lactate and heat-shock on texture in fresh-cut lettuce during storage  

Microsoft Academic Search

\\u000aTextural and microstructural changes in fresh-cut lettuce were analysed over 12?days storage. The vegetable was treated with 120?ppm chlorine and with 15?g\\/L calcium lactate at room temperature (~18-20??C) and at 50??C (heat-shock). Texturometer analysis showed that samples washed with calcium lactate had significantly (p?>?0.05) higher crispness values than samples washed with chlorine. However the use of 50??C treatment (heat-shock) gave

Daniel Rico; Gary Henehan; Jemima Mulcahy; J. M. Barat; Catherine Barry-Ryan; Jesus M. Frias

2006-01-01

342

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, Héctor C

2014-04-01

343

A model for achieving 1 terabit/sq.in. storage density by heat-assisted magnetic probe recording  

NASA Astrophysics Data System (ADS)

A method of heat-assisted magnetic recording (HAMR) is characterized. The recording medium is a high coercitivity, granular and perpendicular CoNi/Pt multilayered film. Emission current from a scanning tunneling microscope(STM) is the heating source. Experiments show that an average mark size of 90 120nm is achieved. A model for achieving 1terabit/sq.in. recording density(or a mark size of 25nm) is proposed to guide future effort.

Zhang, L.

2006-08-01

344

A model for achieving 1 terabit\\/sq.in. storage density by heat-assisted magnetic probe recording  

Microsoft Academic Search

A method of heat-assisted magnetic recording (HAMR) is characterized. The recording medium is a high coercitivity, granular and perpendicular CoNi\\/Pt multilayered film. Emission current from a scanning tunneling microscope(STM) is the heating source. Experiments show that an average mark size of 90 120nm is achieved. A model for achieving 1terabit\\/sq.in. recording density(or a mark size of 25nm) is proposed to

L. Zhang

2006-01-01

345

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

346

Forsoegsborehulslager og ombygning af damvarmelager til gruslager. (Experimental borehole heat storage and conversion of a duct storage facility to gravel pit storage).  

National Technical Information Service (NTIS)

Investigations had pointed to an expected applicability of duct storage as seasonal storage in collective solar plants. Testing of a 540 m(sup 3) test pit, a waterfilled gravel pit functioning as an artificial acquifer as well as a pipecoil operated grave...

V. Ussing

1991-01-01

347

Simulering af termiske forhold i solvarmeanlaeg med saesonlagring. (Simulation of thermal conditions in a solar heating system with seasonal storage).  

National Technical Information Service (NTIS)

Ideas for calculation of isolines using input data given in either a regular, or an irregular, net have been tested. A numerical model for a solar energy system consisting of a smaller ground storage, a solar collector and a heat pump has been developed. ...

P. Berg

1988-01-01

348

Seasonal Heat Storage in Underground Warm Water Stores: Construction and Testing of a 500 m3 Store.  

National Technical Information Service (NTIS)

The aim of the work has been to show that warm water pits, uninsulated towards the soil are well suited for seasonal heat storage. Limiting the insulation to the top surface will contribute to a construction price reduction, which is so important, if seas...

K. K. Hansen P. N. Hansen V. Ussing

1983-01-01

349

Seasonal Heat Storage in Underground Warm Water Stores. Construction and Testing of a 500 M exp 3 Store.  

National Technical Information Service (NTIS)

The aim of the work has been to show that warm water pits, uninsulated towards the soil are well suited for seasonal heat storage. Limiting the insulation to the top surface will contribute to a construction price reduction, which is so important, if seas...

K. Kielsgaard Hansen P. Nordgaard Hansen V. Ussing

1983-01-01

350

Fortsatte maalinger paa 500 cu m forsoegsvarmelager. (Continued measurements of a 500 cu m test heat storage facility).  

National Technical Information Service (NTIS)

A continuation of a measuring programme with a connected simulation of the operation of, and verification of a calculation programme for, a test heat storage facility with a volume of 500 m(sup 3) meters. The computer programme for the calculation of temp...

K. Kielsgaard Hansen P. Nordgaard Hansen V. Ussing

1985-01-01

351

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 20°C 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 20°C. However, polyethylene bag packaging or low

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

2004-01-01

352

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

SciTech Connect

A simplified design procedure is examined for estimating the storage capacity and collector area for annual-cycle-storage, community solar heating systems in which 100% of the annual space heating energy demand is provided from the solar source for the typical meteorological year. Hourly computer simulations of the performance of these systems were carried out for 10 cities in the United States for 3 different building types and 4 community sizes. These permitted the use of design values for evaluation of a more simplified system sizing method. Results of this study show a strong correlation between annual collector efficiency and two major, location-specific, annual weather parameters: the mean air temperature during daylignt hours and the total global insolation on the collector surface. Storage capacity correlates well with the net winter load, which is a measure of the seasonal variation in the total load, a correlation which appears to be independent of collector type.

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

1980-01-01

353

Heat and mass transfer in the process of movement of water drops in a high-temperature gas medium  

NASA Astrophysics Data System (ADS)

The heat and mass transfer in the process of movement of water drops in a high-temperature gas medium was numerically investigated. The regimes and conditions of formation of the zone of mutual influence of two drops were determined on the basis of an analysis of the temperature and concentration fields of the water vapor in the neighborhood of the trajectory of movement of the drops. The times of existence (complete evaporation) of one and two drops as a result of their interaction with the high-temperature products of combustion of a typical condensed liquid substance were compared. It has been established that only in the case where the distance between the two drops is small is the intensity of evaporation of water from them substantially lower than that of a single drop.

Vysokomornaya, O. V.; Kuznetsov, G. V.; Strizhak, P. A.

2013-01-01

354

Formation and catalytic activity of high molecular weight soluble polymers produced by heating amino acids in a modified sea medium  

NASA Astrophysics Data System (ADS)

Eighteen protein amino acids with milk casein composition were heated in a modified sea medium. Marigranules were formed in the precipitates and soluble polymers were formed in the supernatant. Time course of the reaction (ultraviolet spectra, the concentration of metal ions, and the concentration of amino acids in the supernatant) were measured. The time course of the formation of the soluble polymers was also studied by Bio-Gel P-2 column. High molecular weight soluble polymers (HMWSP) were separated from low molecular weight ones by dialysis. It was shown that these polymers catalyzed the dehydrogenation of NADH. These polymers also catalyzed the coupled reaction between dehydrogenation of NADH and reduction of resazurin. This coupled reaction was accelerated by the light.

Okihana, Hiroyuki

1982-06-01

355

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

356

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

357

The behavior of a long term heat storage system in connection with a wind energy converter (phase 1)  

NASA Astrophysics Data System (ADS)

The technical and economical feasibility of heating a museum on the Wasserkuppe mountain (950 m) in the Rhoen hills by wind energy is affirmed. It is possible to recover the capital cost within a period of 15 to 19 years if the service life of the wind energy converter (WEC) and of the heat storage system is between 20 and 30 years. At a maximum thermal load of 120 kW, the minimum cost will be achieved with a WEC power output of 120 kW and a two day storage system. This combination permits 60% of the heat demand to be covered by wind energy. The balance has to be supplied by conventional energy sources. The wind energy fraction of the total energy demand thus is about twice as high as the solar fraction in the case of solar heating systems and about 15% higher than the fraction of ambient heating energy in the case of electric heat pumps used in bivalent operation. The wind price per kWh is already comparable to that expected for the future large wind energy converters (GROWIAN) to be produced in series.

Auer, F.; Bley, H.; Mueller, M.

1982-04-01

358

Effects of outside storage on the energy potential of hardwood particulate fuels. Part II. Higher and net heating values  

SciTech Connect

Fuel management planning requires knowledge of what happens to woody materials when stored outdoors in large piles. Part I of this series reported temperature and moisture content (MC) changes in cone-shaped piles up to 20 feet high. This paper reports changes in higher and net heating values. Higher heating values of the three fuels studied - hardwood whole-tree chips, bark, and sawdust - were relatively constant during the first 4 months of storage. By the end of the year, however, they declined by 9, 7, and 3%, respectively. These decreases coupled with increases in fuel MC resulted in significant declines in average net heating values. After 1 year of storage in 15-foot piles, average net heating values of whole-tree chips, sawdust, and bark declined by 24, 40, and 50%, respectively. Over half of the decline took place in the first 60 days. Losses for whole-tree chips were less when stored in 20-foot piles than when stored in 10- or 15-foot piles. Losses can be reduced by storing larger sized particles, increasing pile heights, and shortening storage cycles to 60 days or less.

White, M.S.; Curtis, M.L.; Sarles, R.L.; Green, D.W.

1983-11-01

359

Effects of outside storage on the energy potential of hardwood particulate fuels. II. Higher and net heating values  

SciTech Connect

Fuel management planning requires knowledge of what happens to woody materials when stored outdoors in large piles. Part 1 of this series reported temperature and moisture content (MC) changes in cone-shaped piles up to 20 feet high. This paper reports changes in higher and net heating values. Higher heating values of the three fuels studied hardwood whole-tree chips, bark, and sawdust were relatively constant during the first four months of storage. By the end of the year, however, they declined by 9%, 7%, and 3%, respectively. These decreases coupled with increases in fuel MC resulted in significant declines in average net heating values. After one year of storage in 15-foot piles, average net heating values of whole-tree chips, sawdust, and bark declined by 24%, 40%, and 50%, respectively. Over half of the decline took place in the first 60 days. Losses for whole-tree chips were less when stored in 20-foot piles than when stored in 10- or 15-foot piles. Losses can be reduced by storing larger sized particles, increasing pile heights, and shortening storage cycles to 60 days or less. (Refs. 8).

White, M.S.; Curtis, M.L.; Sarles, R.L.; Green, D.W.

1983-01-01

360

Solar heating system  

SciTech Connect

A solar heating system including a flat plate solar collector having a heat absorber woven basket fashion across a riser grid system containing suitable flow medium for being heated by the solar radiation. A heat exchange column is coupled to the riser grid system for extracting the heat from the flow medium to provide it to heating, hot water, and the like. The heat exchange column includes a number of continuous coils placed within a tank and having a circulating loop pass a liquid from the bottom of the tank to the top of the tank where it will flow over all of the coils transferring heat from one coil to the other. The flow is controlled by means of the load demand and the available supply of heat. Excess heat is stored in a heat storage system having a plurality of blocks of Glauber salt containing matrix material through which pass pipes containing the heated liquid. One of the riser grid systems can be utilized as part of an absorption cycle air conditioning system by passing the heated fluid medium into a regenerator placed adjacent to the collector to effectively form a distillation process. In place of the liquid solar collector, an air heating solar collector is also provided.

Steinberg, A.

1984-02-07

361

Unsteady mass transfer in mixed convective heat flow from a vertical plate embedded in a liquid-saturated porous medium with melting effect  

Microsoft Academic Search

This paper numerically studies the transient mass transfer in mixed convective heat flow with melting effect from a vertical plate in a liquid saturated porous medium in the presence of aiding external flow. The governing equations are transformed into the non-dimensional form by using pseudo similarity coordinate (?) and dimensionless time (?). The resulting two dimensional boundary value problem (BVP)

W. T. Cheng; C. H. Lin

2008-01-01

362

Non-Darcy unsteady mixed convection flow near the stagnation point on a heated vertical surface embedded in a porous medium with thermal radiation and variable viscosity  

Microsoft Academic Search

The unsteady mixed convection boundary layer flow near the stagnation point on a heated vertical plate embedded in a fluid saturated porous medium is studied. It is assumed that the unsteadiness is caused by the impulsive motion of the free stream velocity and by sudden increase in the surface temperature. Both the buoyancy assisting and the buoyancy opposing flow situations

I. A. Hassanien; T. H. Al-Arabi

2009-01-01

363

SODHA. A Data Program for Minimizing the Cost Function of a Solar Farm with Storage Connected to a District Heating System.  

National Technical Information Service (NTIS)

SODHA is a program for minimizing the investment needed for a solar plant supplying a district heating system. The plant consists of a solar farm, storage and a heat exchanger connected to a district heating network. By using SODHA it is possible to optim...

R. Haakansson S. Rolandsson

1982-01-01

364

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

365

Use of video-based Particle Image Velocimetry technique for studies of velocity fields in a water heat storage vessel  

Microsoft Academic Search

A video-based Particle Image Velocimetry technique has been developed. The technique is particularly suitable for measurement of small velocities, below 3 cm\\/s. It has proved to be useful for the documentation of non-stationary velocity fields in a scaled-down model of a water heat storage vessel. An ordinary video camera is used to record the in-plane movements of particles in a

J. Dahl; R. Hermansson; S.-E. Tiberg; P. Veber

1995-01-01

366

The heating of a thermally conducting stratified medium. II - A simple plane model of an atmosphere. [of sun  

NASA Technical Reports Server (NTRS)

Exact solutions of the following theoretical problem are presented: A plane atmosphere is in hydrostatic equilibrium with a uniform gravity. The ideal gas law is assumed. Heat is generated everywhere at a rate proportional to the local density. The atmosphere is maintained in a steady state through cooling by thermal conduction and radiation. This problem is reducible to quadratures for a thermal conductivity which is an arbitrary, but prescribed, function of the temperature, and for a radiative loss which is expressible as the product of the density and an arbitrary, but prescribed, function of the pressure. The analysis is carried out for the case of power law thermal conductivity, and a radiative loss proportional to the square of the density and to the first power of the temperature. The radiative cooling function adopted here has the basic mathematical form for an optically thin medium. The solutions reproduce the macroscopic ordering of a hot 'corona' separated from a 'photosphere' by a layer of temperature minimum. The analytic solutions allow direct illustration of the interplay between steady energy transport and the requirements of hydrostatic equilibrium.

Lerche, I.; Low, B. C.

1980-01-01

367

Li-decorated metal-organic framework 5: A route to achieving a suitable hydrogen storage medium  

PubMed Central

A significant improvement in molecular hydrogen uptake properties is revealed by our ab initio calculations for Li-decorated metal–organic framework 5. We have found that two Li atoms are strongly adsorbed on the surfaces of the six-carbon rings, one on each side, carrying a charge of +0.9e per Li atom. Each Li can cluster three H2 molecules around itself with a binding energy of 12 kJ (mol H2)?1. Furthermore, we show from ab initio molecular dynamics simulations with a hydrogen loading of 18 H2 per formula unit that a hydrogen uptake of 2.9 wt % at 200 K and 2.0 wt % at 300 K is achievable. To our knowledge, this is the highest hydrogen storage capacity reported for metal–organic framework 5 under such thermodynamic conditions.

Blomqvist, A.; Araujo, C. Moyses; Srepusharawoot, P.; Ahuja, R.

2007-01-01

368

Recording and reading temperature tolerance in holographic data storage, in relation to the anisotropic thermal expansion of a photopolymer medium.  

PubMed

In holographic data storage, it is difficult to retrieve data if the temperature difference between recording and reading exceeds 2 K. To widen this tolerance, a compensation method--adjusting the wavelengths and incident directions of the recording and reading beams--has been proposed. In this paper, for the first time, a method for calculating the recording and reading temperature tolerance using this compensation is introduced. To widen the narrow tolerance, typically +/- 10 K, it is effective to increase the coefficient of thermal expansion (CTE) of the substrate or decrease the CTE of the photopolymer. Although reducing the Numerical aperture of the objective lens is also effective, it degrades the recording density. PMID:19654823

Tanaka, Tomiji

2009-08-01

369

Fundamental study of cold heat-storage system of O/W-type emulsion having cold latent-heat-dispersion material. Part 1  

SciTech Connect

This paper deals with thermal properties of an oil (tetradecane, C{sub 14}H{sub 30}, melting point 278.9K)/water emulsion as a latent heat-storage material having a low melting point. The measured results of the physical properties of the test emulsion, that is, thermal conductivity, specific heat, latent heat, and density, are discussed for the temperature region of solid and liquid phases of the dispersion material (tetradecane). It is clarified that Eucken`s equation can be applied to the estimation of the thermal conductivity of the emulsion. Moreover, it is established that tetradecane as the dispersion material exhibits a supercooling phenomenon which influences the thermal properties. Useful correlation equations of the thermal properties for the emulsion were proposed in terms of temperature and concentration ratio of the emulsion constituents.

Inaba, Hideo; Morita, Shinichi; Nozu, Shigeru [Okayama Univ. (Japan)

1995-02-01

370

Research on solar energy storage subsystems utilizing the latent heat of phase change of paraffin hydrocarbons for the heating and cooling of buildings. Semi-annual report, September 1, 1974March 31, 1975  

Microsoft Academic Search

An analytical and experimental research program designed to assess the potential of a solar energy storage subsystem (thermal capacitor) utilizing the latent heat of fusion of paraffin hydrocarbons for the heating and cooling of buildings, and supported with grant funds from the National Science Foundation, is described. An idealized model of a flat plate thermal capacitor based on uniaxial heat

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

1975-01-01

371

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

SciTech Connect

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

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

1986-06-01

372

Validation of a postfixation tissue storage and transport medium to preserve histopathology and molecular pathology analyses (total and phosphoactivated proteins, and FISH).  

PubMed

Tumor biomarker studies are integral to oncology clinical trials but may yield artifactual results owing to variation in sample procurement and processing. Ethanol, 70% vol/vol, was validated as a sample transport medium using markers of the PI3K/Akt/mTOR pathway. BT474 tumor xenografts were excised and slices were immediately placed into formaldehyde and fixed for 24 hours. Fixed tissue slices were immediately processed into paraffin or transferred to 70% vol/vol ethanol and stored at room temperature for 1, 2, and 4 weeks before further processing. Freshly cut tissue sections were evaluated for pAKT(S473), HER2, pHER-2(Y1248), pS6(S235/236), and pS6(S240/244), Ki-67, and HER2 by fluorescence in situ hybridization and stained with H&E and Masson trichrome. No significant changes were observed when comparing samples stored in 70% ethanol for up to 4 weeks with immediately processed tissue. Ethanol, 70% vol/vol, provides a safe storage medium for formaldehyde-fixed tumor tissue, facilitating sample transport during multicenter clinical trials. PMID:22338055

Stumm, Michael M; Walker, Maja R; Stork, Caroline; Hanoteau, Noelle; Wagner, Urs; O'Reilly, Terence M

2012-03-01

373

Two heterologously expressed Planobispora rosea proteins cooperatively induce Streptomyces lividans thiostrepton uptake and storage from the extracellular medium  

PubMed Central

Background A bacterial artificial chromosomal library of Planobispora rosea, a genetically intractable actinomycete strain, was constructed using Escherichia coli-Streptomyces artificial chromosome (ESAC) and screened for the presence of genes known to be involved in the biosynthesis of antibiotics. Results One clone with a 40 kb insert showed antimicrobial activity against Gram positive bacteria. Insert sequence analysis and subcloning experiments revealed that the bioactivity was due to a 3.5 kb DNA fragment containing two open reading frames. These orfs encode two proteins with high similarity to a putative membrane protein of Streptomyces coelicolor and to the nogalamycin resistance protein SnorO of Streptomyces nogalater, respectively. The role of these two Orfs is unknown in Planobispora. Disruption and complementation experiments revealed that both proteins are necessary for the antibacterial activity and chemical analysis demonstrated that the antibiotic activity was due to thiostrepton, antibiotic used as recombinant clone selection marker. Conclusion Two Planobispora rosea orfs are responsible for increasing intracellular amounts and storage of thiostrepton in Streptomyces lividans.

2010-01-01

374

Numerical study of the performance of latent heat storage for solar dynamic power systems. [Brayton cycle  

Microsoft Academic Search

A conceptual design of a space station power system based on a Brayton cycle and solar powered has been developed. A key component of such a system is the thermal energy storage module, which is of crucial importance during periods of darkness. We have developed a computer program - FPAK1.F, simulating one possible storage design. We describe the code and

1985-01-01

375

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

Microsoft Academic Search

A conceptual design of a space station power system based on a Brayton cycle and solar power has been developed. A key component of such a system is the thermal energy storage module, which is of crucial importance during periods of darkness. We have developed a computer program - FPAK1.F, simulating one possible storage design. We describe the code and

A. D. Solomon

1985-01-01

376

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

Microsoft Academic Search

A conceptual design of a space station power system based on a Brayton cycle and solar powered has been developed. A key component of such a system is the thermal energy storage module, which is of crucial importance during periods of darkness. We have developed a computer program, FPAK1.F, simulating one possible storage design. We describe the code and, using

A. D. Solomon

1986-01-01

377

Review on thermal energy storage with phase change: materials, heat transfer analysis and applications  

Microsoft Academic Search

Thermal energy storage in general, and phase change materials (PCMs) in particular, have been a main topic in research for the last 20 years, but although the information is quantitatively enormous, it is also spread widely in the literature, and difficult to find. In this work, a review has been carried out of the history of thermal energy storage with

Bele en Zalba; José M Mar??n; Luisa F. Cabeza; Harald Mehling

2003-01-01

378

The effect of heat shrink treatment and storage temperature on the time of onset of "blown pack" spoilage.  

PubMed

This study determined the effects of (a) the short "heat shrink" treatment frequently applied to vacuum packed meats within normal commercial production, and (b) chill holding storage temperature, on the subsequent time to onset (TTO) of "blown pack" spoilage (BPS). Beef or lamb steaks were inoculated with 10³ CFU/cm² of spore suspensions of five gas producing clostridia, vacuum packed (VP) and treated as follows: no heat, 50°C/15 s, 70°C/10 s or 90°C/3 s. Samples were stored at -1.5, 1 or 4°C and examined daily to determine TTO of BPS. For each strain, pack treatment and storage temperature had significant (P<0.05 and P<0.001 respectively) effects on TTO of BPS, i.e. 90°C/3 s<70°C/10 s<50°C/15 s?"no heat", and 4°C<1°C<-1.5°C. The study suggested that the meat industry could reduce the risks of BPS by avoiding higher temperature (90°C/3 s or 70°C/10 s) heat shrinking, and by storing VP meats at lower temperatures (e.g. -1.5°C). PMID:20937550

Moschonas, Galatios; Bolton, Declan J; Sheridan, James J; McDowell, David A

2011-02-01

379

Analysis of cooling cycles with clathrate energy storage  

SciTech Connect

A prototype is presented of a thermal energy storage facility, with an appropriate storage medium, that can be applicable in environmental control of residential and commercial buildings. A simulated heat pump cooling system which utilizes a refrigerant gas hydrate as a storage medium was experimentally and theoretically analyzed. Numerous closed loop cycles using a clathrate in direct contact heat transfer with the refrigerant were evaluated to verify the system operation and to evaluate the system components. The basic background of the direct contact heat transfer method in which heat transfer enhancement is achieved is investigated. The aim is to provide clear theoretical insights to the phase change of the storage medium (clathrate), and present a mathematical model that is compatible with the latent heat release rate. A finite difference computer code utilizing the apparent heat capacity model was developed to predict the experimental temperature fields inside an insulated cylindrical horizontal thermal energy storage tank as time progresses. The experimental and theoretical results show that clathrate energy storage and direct contact heat transfer are technically feasible.

Gadalla, M.A.

1988-01-01

380

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

381

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

382

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

SciTech Connect

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 constant. The effects of variations of the shock Mach number, the Alfven Mach number, the radiation parameter and the gravitation on flow field behind the shock wave are shown graphically and discussed.

Sharma, Pankaj [Department of Applied Mathematics, Jawaharlal Institute of Technology, Borawan, Khargone-451228 (India); Sharma, Vivek Kumar [Department of Applied Mathematics and Computational Science, Shri G. S. Institute of Technology and Science, 23, Park Road, Indore-452003 (India)

2009-07-02

383

Temperature conditioning system suitable for use with a solar energy collection and storage apparatus or a low temperature energy source  

Microsoft Academic Search

A temperature conditioning system employing an ejector-type compressor and a refrigerant selected for operation at the limited operating temperatures of a heat energy collection and storage apparatus. Improved performance may be achieved by employing a two-tank storage system having a control circuit for supplying heat transfer medium from the hotter of the tanks for return to the cooler.

Briley

1983-01-01

384

Temperature conditioning system suitable for use with a solar energy collection and storage apparatus or a low temperature energy source  

SciTech Connect

A temperature conditioning system employing an ejector-type compressor and a refrigerant selected for operation at the limited operating temperatures of a heat energy collection and storage apparatus. Improved performance may be achieved by employing a two-tank storage system having a control circuit for supplying heat transfer medium from the hotter of the tanks for return to the cooler.

Briley, P.B.

1983-02-22

385

Effects of Basicity and B2O3 on the Crystallization and Heat Transfer Behaviors of Low Fluorine Mold Flux for Casting Medium Carbon Steels  

NASA Astrophysics Data System (ADS)

An investigation was carried out to study the effects of basicity (CaO/Si2O) and B2O3 on the crystallization and heat transfer behaviors of low fluorine mold flux for casting medium carbon steels. The double hot thermocouple technique (DHTT) was employed to study the crystallization behavior of mold flux with a different basicity and B2O3 content, under the simulated thermal gradient as in a real caster. The infrared emitter technique (IET) was also applied for the study of heat transfer behavior of the above mold fluxes. By combining the results of IET and DHTT, this article indicated that the increase of basicity would decrease the general heat transfer rate of mold flux, as it tends to promote crystallization of mold flux apparently, while B2O3 has the opposite function. The combined effects of basicity and B2O3 could be used to adjust the general crystallization and heat transfer properties of low fluorine mold flux for casting medium carbon steels, which would provide an instructive way for the design of Fluorine free mold flux for casting medium carbon steels.

Lu, Boxun; Wang, Wanlin; Li, Jin; Zhao, Huan; Huang, Daoyuan

2013-04-01

386

Preliminary design study of a central solar heating plant with seasonal storage at the University of Massachusetts, Amherst  

NASA Astrophysics Data System (ADS)

This report documents the design development and selection of the final preliminary design of a Central Solar Heating Plant with Seasonal Storage (CSHPSS) for the University of Massachusetts in Amherst (UMass). The effort has been performed by the Department of Mechanical Engineering at UMass under contract with the U.S. Department of Energy. Phase 1 of this project was directed at site selection for the CSHPSS project and was reported earlier. This report focuses on the Phase 2 development of the site conditions and analytical study of project design, performance, and cost. The UMass site presents an excellent opportunity of a CSHPSS project in terms of land availability for a large collector array, a 100 foot deep deposit of soft, saturated clay for seasonal thermal energy storage, and appropriate low temperature heating loads. The project under study represents the first implementation of this solar technology in the United States and results from the International Energy Agency collaboration on CSHPSS since 1979. The preliminary design calls for a large 10,000 m(exp 2) parabolic trough collector array, 70,000 m(exp 3) storage volume in clay with heat transfer through 900 boreholes. Design optimization is based on computer simulations using MINSUN and TRNSYS. The design is expected to provide 95 percent of the 3500 MWh heating and hot water load. A project cost of $3.12 million (plus $240,000 for HVAC load retrofit) is estimated, which provides an annualized cost of $66.2/MWh per unit solar energy delivered. The project will proceed into an engineering phase in Spring 1991.

Breger, D. S.; Sunderland, J. E.

1991-04-01

387

Solutions for modelling moving heat sources in a semi-infinite medium and applications to laser material processing  

Microsoft Academic Search

This study describes the analytical and numerical solution of the heat conduction equation for a localised moving heat source of any type for use in laser material processing, as welding, layered manufacturing and laser alloying. In this paper, the analytical solution for a uniform heat source is derived from the solution of an instantaneous point heat source. The result is

M. Van Elsen; M. Baelmans; P. Mercelis; J.-P. Kruth

2007-01-01

388

Performance investigation of a long, slender, heat pipe for thermal energy storage applications  

SciTech Connect

The application of heat pipes as heat transport elements in a latent heat thermal energy store for solar heating systems is proposed. The paper describes the development of a long and slender, axially grooved, cooper-water heat pipe, 20 mm in diameter and 3070 mm long. The heat pipe, charged with a liquid overfill, was operated with slight gravity assistance and tessted in varrious operational modes that simulated charging, discharging, and bypass of the heat store. Periodic temperature oscillations at the evaporator wall, dependent on the amount of liquid overfill and heat pipe tilt, resulted in adverse performance, forcing modifications in the capillary structure. An entrainment model to describe the wall temperature oscillations is presented. Futhermore, results from three test series, characterized the type of capillary structure used, are discussed.

Abahat, A.

1982-11-01

389

Preparatory experiments on seasonal storage in earth of excess heat from greenhouse  

NASA Astrophysics Data System (ADS)

An earth heat accumulator, directly beneath an experimental greenhouse, with possibilities for collecting excess solar heat by pumps and utilization of low temperature heat was investigated. Heat exchange with the accumulator is made by a system of buried polyethylene pipes. The heat accumulator was loaded by excess solar heat from the greenhouse, using heat pumps, during two summer months. A theoretical model for the heat flow in the accumulator was used to study the heat balance in the accumulator and its interaction with surrounding soil and greenhouse. The heat flow through the soil surface is utilized by the greenhouse giving a higher root zone temperature and a higher air temperature. It is suggested that a heat accumulator should be placed deeper beneath the soil surface. Its extension in depth should be larger, (about 10 to 15 m) in the specific boulder clay investigated. It is concluded that the method which uses buried horizontal pipes is not usable, and a technique for vertical pipe systems with high heat transfer must be investigated.

Areskoug, M.; Wigstroem, P.

1980-12-01

390

Conceptual design selection and development of a latent-heat thermal-energy-storage subsystem for a saturated-steam solar receiver and load  

SciTech Connect

The following latent heat storage concepts are described and evaluated in comparison with each other and with an oil/rock sensible heat storage system: (1) passive tube intensive (shell-and-tube heat exchanger) with and without heat transfer enhanced by fins; (2) phase change material cans (or chubbs) with a biphenyl intermediate heat transfer fluid; (3) phase change material macroencapsulation in a containment tank full of tubes; (4) microencapsulation in a porous carrier; (5) direct contact heat exchange; and (6) systems using mechanical scrapers for removing solidified phase change material from container surfaces. A tube intensive system with heat transfer enhancement was selected, and the conceptual design and cost/performance estimates are given for it. A commercial scale unit is assessed, and design changes and corresponding costs are presented that would be required to make the system meet changed requirements. (LEW)

Not Available

1981-02-01

391

Helical flows of a heated generalized Oldroyd-B fluid subject to a time-dependent shear stress in porous medium  

NASA Astrophysics Data System (ADS)

This paper presents an analysis for helical flows of a heated generalized Oldroyd-B fluid subject to a time-dependent shear stress in porous medium, where the motion is due to the longitudinal time-dependent shear stress and the oscillating velocity in boundary. The exact solutions are established by using the sequential fractional derivatives Laplace transform coupled with finite Hankel transforms in terms of generalized G function. Moreover, the effects of various parameters (relaxation time, fractional parameter, permeability and porosity) on the flow and heat transfer are analyzed in detail by graphical illustrations.

Li, Chunrui; Zheng, Liancun; Zhang, Yue; Ma, Lianxi; Zhang, Xinxin

2012-12-01

392

Relationship between the apparent heat resistance of Bacillus cereus spores and the pH and NaCl concentration of the recovery medium  

Microsoft Academic Search

Conventional heat resistance data, D values, were previously established by other workers at optimal condition for spores outgrowth. However, in canned food conditions of outgrowth are generally suboptimal in term of pH, salt concentration, water activity. The combined effects of pH and NaCl level of the recovery medium for the D value and zpH value were studied. Spores of Bacillus

Ivan Leguerinel; Olivier Couvert; Pierre Mafart

2000-01-01

393

Influence of heat treatment on microstructure and mechanical properties of CVI-CFC composites with medium and highly textured pyrocarbon matrices  

Microsoft Academic Search

The influence of heat treatment up to 2900°C on microstructure and mechanical properties of CVI-infiltrated carbon fiber felts with either medium (MT) or highly (HT) textured pyrocarbon matrices was studied by optical and scanning electron microscopy, X-ray diffraction, and three-point bending tests. The microstructural investigations of the HT-samples reveal a pronounced decrease of the interlayer spacing d002 with a simultaneous

Moez Guellali; R. Oberacker; M. J. Hoffmann

2008-01-01

394

The effect of impurities on the melting temperature and the heat of fusion of latent heat storage materials  

Microsoft Academic Search

Thermophysical properties of four normal paraffins (tetradecane, hexadecane, octadecane, eicosane) and three fatty acids (lauric acid, palmitic acid, stearic acid) were determined experimentally using a modified differential-thermoanalysis technique. For calibration of the measuring device, literature data in the temperature range from 5 to 70°C of six of these substances of at least 99% purity were used. Melting temperature, heat of

J. Sohns; B. Seifert; E. Hahne

1981-01-01

395

Modeling of absorption heat pumps: solar applications employing chemical storage and steady-state modeling with a comparison to experiments  

SciTech Connect

This work develops simulation models for absorption heat pumps (AHPs) with the goal of enabling a more analytical approach to their study and design. A continuous, liquid absorbent AHP with chemical storage is modeled using mass and energy balances and assuming mass transfer equilibrium. This model is used with the TRNSYS program to simulate the performance of an AHP in a residential solar-driven heating and cooling system. The steady-state and cyclic testing of a prototype gas-fired ammonia-water AHP in an environmental chamber is described; measurements include temperatures, pressures, absorbent concentrations, flow rates and heat flows. The coefficient of performance and heating capacity depend most strongly on ambient temperature; varying the load water temperature and flow rate has lesser effects. The performance of the unit is sensitive to refrigerant charge, with the optimum charge varying with ambient temperature. This AHP shows a significant performance degradation in cyclic operation. A modular, steady-state simulation program for absorption heat pumps in developed and validated with experimental data. The model utilizes an analysis of the refrigerant and absorbent inventory to set the system pressures.

McLinden, M.O.

1984-01-01

397

Enhanced geothermal systems (EGS) with CO2 as heat transmission fluid--A scheme for combining recovery of renewable energy with geologic storage of CO2  

Microsoft Academic Search

It has been suggested that enhanced geothermal systems (EGS) may be operated with supercritical CO instead of water as heat transmission fluid (D.W. Brown, 2000). Such a scheme could combine recovery of geothermal energy with simultaneous geologic storage of CO, a greenhouse gas. At geothermal temperature and pressure conditions of interest, the flow and heat transfer behavior of CO would

K. Pruess; N. Spycher

2009-01-01

398

Energy capacity reduction of energy storage system in microgrid by use of heat pump: Characteristic study by use of actual machine  

Microsoft Academic Search

The installation of renewable energy sources based generators such as photovoltaic cells and wind turbines require energy storage systems(ESSs) to control power fluctuation. ESSs, however, are quite expensive. In order to reduce the necessary capacity of ESSs for microgrid applications, the control of heat pumps is researched. In this research, basic characteristic of a heat pump's power consumption is measured

Shunsuke KAWACHI; Jumpei BABA; H. Hagiwara; E. Shimoda; S. Numata; E. Masada; T. Nitta

2010-01-01

399

Advanced latent heat of fusion thermal energy storage for solar power systems  

NASA Astrophysics Data System (ADS)

The use of solar thermal power systems coupled with thermal energy storage (TES) is being studied for both terrestrial and space applications. In the case of terrestrial applications, it was found that one or two hours of TES could shift the insolation peak (solar noon) to coincide with user peak loads. The use of a phase change material (PCM) is attractive because of the higher energy storage density which can be achieved. However, the use of PCM has also certain disadvantages which must be addressed. Proof of concept testing was undertaken to evaluate corrosive effects and thermal ratcheting effects in a slurry system. It is concluded that the considered alkali metal/alkali salt slurry approach to TES appears to be very viable, taking into account an elimination of thermal ratcheting in storage systems and the reduction of corrosive effects. The approach appears to be useful for an employment involving temperatures applicable to Brayton or Stirling cycles.

Phillips, W. M.; Stearns, J. W.

1985-12-01

400

Solar energy storage via liquid filled cans - Test data and analysis  

NASA Technical Reports Server (NTRS)

This paper describes the design of a solar thermal storage test facility with water-filled metal cans as heat storage medium and also presents some preliminary tests results and analysis. This combination of solid and liquid mediums shows unique heat transfer and heat contents characteristics and will be well suited for use with solar air systems for space and hot water heating. The trends of the test results acquired thus far are representative of the test bed characteristics while operating in the various modes.

Saha, H.

1978-01-01

401

The DRESOR method for radiative heat transfer in a one-dimensional medium with variable refractive index  

NASA Astrophysics Data System (ADS)

This paper extends the DRESOR (Distribution of Ratios of Energy Scattered by the medium Or Reflected by the boundary surface) method to radiative transfer in a variable refractive index medium. In this method, the intensity is obtained from the source term along the curved integration paths determined only by the variable refractive index, and the DRESOR values are calculated by the Monte Carlo method in which the propagation of the energy bundles are affected by Snell's law. With given temperatures on the black boundaries of a one-dimensional medium, the temperature distribution inside the medium with a variable scattering property is calculated under the condition of radiative equilibrium. It is shown that the DRESOR method has a good accuracy in the cases studied. For an isotropic-scattering medium with the same optical thickness, the scattering albedo has no effect on the temperature distribution, which can be obtained from the general equations and can be seen as an extension of what exists for a constant refractive index; however, the different refractive index causes obvious changes in the temperatures inside the medium. The effect of anisotropic scattering on the temperature distribution cannot be ignored, although it is still weaker than the effect caused by variation in the refractive index.

Wang, Zhichao; Cheng, Qiang; Wang, Guihua; Zhou, Huaichun

2011-12-01

402

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

403

An Application of Solar Energy Storage in the Gas: Solar Heated Biogas Plants  

Microsoft Academic Search

Temperature is an important factor that may affect the performance of anaerobic digestion. Therefore, biogas plants without heating system work only in warmer regions for the whole year. In regions with extreme temperature variations, for instance in Turkey, the biogas plant should be built with heating system. One of the methods is to use solar energy to increase the reactor

G. Kocar; A. Eryasar

2007-01-01

404

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

405

Seasonal Heat Storage in Underground Warm Water Stores. Dimensioning and Planning of a Full Size Store.  

National Technical Information Service (NTIS)

The aim of the work has been to use the experience gained in prior work to complete the design of a full size (about 50,000 m exp 3 ) underground warm water storage. Based on geotechnical investigations a location for the pond was chosen in the vicinity o...

K. Kielsgaard Hansen P. Nordgaard Hansen V. Ussing

1984-01-01

406

Heat-Engine/Mechanical-Energy-Storage Hybrid Propulsion Systems for Vehicles.  

National Technical Information Service (NTIS)

An analytical study indicated that a flywheel-only propulsion system could satisfy the performance requirements specified by the Office of Air Programs, Environmental Protection Agency, for a city bus, and that flywheel/heat engine hybrids could meet the ...

G. L. Dugger A. Brandt J. F. George L. L. Perini D. W. Rabenhorst

1972-01-01

407

Evaluation of Industrial Advanced Heat-Recovery/Thermal-Energy-Storage Systems. Final Report.  

National Technical Information Service (NTIS)

The recovery of waste heat from industrial processes offers significant opportunity for energy conservation provided the available energy source can be matched with a compatible energy consuming sink or end-use process. This investigation involved: examin...

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

1982-01-01

408

Evaluation of Industrial Advanced Heat Recovery/Thermal Energy Storage Systems. Final Report.  

National Technical Information Service (NTIS)

The recovery of waste heat from industrial processes offers significant opportunity for energy conservation provided the available energy source can be matched with a compatible energy-consuming sink or end-use process. This investigation has involved: ex...

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

1982-01-01

409

Cooling and heating system utilizing solar heat  

SciTech Connect

A cooling and heating system utilizing solar heat comprises a heat collector for heating a circulating heat medium with solar heat, an absorption refrigerator operable with the heat medium heated by the heat collector and serving as a generating heat source to provide a chilled medium, and an air-conditioning unit for circulating the chilled medium or the heated medium alternatively therethrough to cool or heat the space to be airconditioned. The system further comprises a bypass line provided with an auxiliary refrigerator of the dual-effect type and connected to an intermediate portion of a line extending from the absorption refrigerator to the air-conditioning unit for supplying chilled medium or the heated medium to the unit. Change -over means is provided for passing the chilled medium or the heated medium through the bypass line.

Katayama, K.; Yukimachi, K.

1981-05-26

410

Optical data storage and metallization of polymers  

NASA Technical Reports Server (NTRS)

The utilization of polymers as media for optical data storage offers many potential benefits and consequently has been widely explored. New developments in thermal imaging are described, wherein high resolution lithography is accomplished without thermal smearing. The emphasis was on the use of poly(ethylene terephthalate) film, which simultaneously serves as both the substrate and the data storage medium. Both physical and chemical changes can be induced by the application of heat and, thereby, serve as a mechanism for high resolution optical data storage in polymers. The extension of the technique to obtain high resolution selective metallization of poly(ethylene terephthalate) is also described.

Roland, C. M.; Sonnenschein, M. F.

1991-01-01

411

Calculation of the radiative heat exchange in a conical cavity of complex configuration with an absorptive medium  

NASA Technical Reports Server (NTRS)

The generalized zonal method is used to calculate the distribution of the temperature factor on the lateral surface of a conical cavity of complex configuration (a Laval nozzle) containing an absorptive medium. The highest values of the radiation density occur on the converging part of the lateral surface of the complex conical cavity (Laval nozzle).

Surinov, Y. A.; Fedyanin, V. E.

1975-01-01

412

Free convection about a vertical flat plate embedded in a porous medium with application to heat transfer from a dike  

Microsoft Academic Search

An analysis is made for steady free convection about a vertical flat plate embedded in a saturated porous medium at high Rayleigh numbers. Within the framework of boundary layer approximations, similarity solutions are obtained for a class of problems where wall temperature varies as xlambda, i.e., a power function of distance from the origin where wall temperature begins to deviate

Ping Cheng; W. J. Minkowycz

1977-01-01

413

EFFECT OF SUCTION AND INJECTION ON MHD THREE DIMENSIONAL COUETTE FLOW AND HEAT TRANSFER THROUGH A POROUS MEDIUM  

Microsoft Academic Search

The objective of this paper is to analyze the effect of constant suction and sinusoidal injection on three dimensional couette flow of a viscous incompressible electrically conducting fluid through a porous medium between two infinite horizontal parallel porous flat plates in presence of a transverse magnetic field. The stationary plate and the plate in uniform motion are, respectively, subjected to

S. S. Das

2009-01-01

414

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

415

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

DOEpatents

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 thermoplastic. The polymer blend can be modified by the addition of at least one of fillers, fibers, fire retardants, compatibilisers, colorants, and processing aids. The polymer blend may be used in applications where advantage can be taken of the absorption of excess heat by a component which remains solid and retains major fractions of its physical and mechanical characteristics while absorbing relatively high quantities of latent heat.

Soroushian, Parviz (Lansing, MI)

2002-01-01

416

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

417

Uniform Mems Chip Temperatures in the Nucleate Boiling Heat Transfer Region by Selecting Suitable, Medium Boiling Number Range  

Microsoft Academic Search

The not only lower but also uniform MEMS chip temperatures can be reached by selecting suitable boiling number range that ensures the nucleate boiling heat transfer. In this article, boiling heat transfer experiments in 10 silicon triangular microchannels with the hydraulic diameter of 155.4 ?m were performed using acetone as the working fluid, having the inlet liquid temperatures of 24–40°C,

J. L. Xu; Y. H. Gan

2007-01-01

418

Effect of 1-MCP prestorage treatment on ethylene and CO 2 production and quality of ‘Hayward’ kiwifruit during shelf-life after short, medium and long term cold storage  

Microsoft Academic Search

The effect of 1-MCP prestorage treatment was studied during short, medium and long term cold storage with subsequent exposures at 20°C (shelf-life) on ethylene and CO2 production, softening, soluble solids contents, titratable acidity, color and decay of ‘Hayward’ kiwifruit (Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson). Application of 1-MCP suppressed or decreased ethylene production during shelf-life at all

Athanasios Koukounaras; Evangelos Sfakiotakis

2007-01-01

419

The influences of pre-incubation storage duration and genotype on the hatchability of Medium White turkey eggs from hens fed a diet containing a yeast culture of Saccharomyces cerevisiae  

Microsoft Academic Search

Two experiments were conducted to determine the effects of feeding turkey breeder hens of different genotypes a diet containing 5 g kg?1 yeast culture (YC) and its effect on pre-incubation egg storage duration (Experiment 1, eggs stored 0–7 and 8–14 days; Experiment 2, eggs stored 0–4, 5–9, and 10–14 days), hen reproductive performance, and the hatchability of fertile eggs.Wrolstad Medium

Gary L. Bradley; Thomas F. Savage

1995-01-01

420

Simulated heat storage in a perennially ice-covered high Arctic lake: Sensitivity to climate change  

Microsoft Academic Search

Perennially ice-covered, meromictic lakes occur along the northern coast of Ellesmere Island in the Canadian high Arctic and have distinctive conductivity and temperature profiles. They are salinity stratified and have deep thermal maxima that persist throughout the year at temperatures up to 60°C above the winter minimum in the overlying atmosphere. Heat transfer in one of these lakes (Lake A,

Aaron C. Vincent; Derek R. Mueller; Warwick F. Vincent

2008-01-01

421

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

Microsoft Academic Search

Materials that can store low temperature latent heat are organic\\/inorganic chemicals, eutectic salt system and clathrate compound. Clathrate compound is the material that host compound in hydrogen bond forms cage and guest compound is included into it and combined. Crystallization of hydrate is generated at higher temperature than that of ice from pure water. And physical properties according to temperature

Chang Oh Kim; Jin Heung Kim; Nak Kyu Chung

2007-01-01

422

Parametric study on the dynamic heat storage capacity of building elements  

Microsoft Academic Search

In modern, extensively glazed office buildings, due to high solar and internal loads and increased comfort ex- pectations, air conditioning systems are often used even in moderate and cold climates. Particularly in this case, passive cooling by night-time ventilation seems to offer considerable potential. However, because heat gains and night ventilation periods do not coincide in time, a suf- ficient

N. Artmann; H. Manz; P. Heiselberg

2007-01-01

423

Medium-density ablative composites: processing, characterisation and thermal response under moderate atmospheric re-entry heating conditions  

Microsoft Academic Search

Medium-density foam composites based on silica fibre-filled phenolic syntactic foams were processed and characterised for\\u000a mechanical, dynamic mechanical and thermophysical properties, and they were evaluated as Thermal Protection Systems (TPSs)\\u000a materials by way of experiment and simulated thermal response studies under atmospheric re-entry conditions. Ablative composites\\u000a with different specific gravities were processed by varying the volume fraction of the constituents.

Bibin John; Dona Mathew; B. Deependran; George Joseph; C. P. Reghunadhan Nair; K. N. Ninan

2011-01-01

424

Temperature of water heat treatments influences tomato fruit quality following low-temperature storage  

Microsoft Academic Search

Mature-green tomato fruit (Lycopersiconesculentum Mill. cv. Sunbeam) were treated in water for 1 h at 27 (ambient), 39, 42, 45, or 48°C, and then either ripened at 20°C (nonchilled) or stored at 2°C (chilled) for 14 days before ripening at 20°C. Treatment at 42°C reduced decay by 60%, whereas the other water temperatures were less effective. Heat treatment had no

R. E. McDonald; T. G. McCollum; E. A. Baldwin

1999-01-01

425

Medium-sized icy satellites in the outer solar system - differentiation due to radiogenic heating in Charon or the moons of Uranus?  

NASA Astrophysics Data System (ADS)

A thermal history model developed for medium-sized icy satellites containing silicate rock at low volume fractions is applied to Charon and five satellites of Uranus. The model assumes stagnant lid convection in homogeneously accreted bodies either confined to a spherical shell or encompassing the whole interior below the immobile surface layer. We employ a simple model for accretion assuming that infalling planetesimals deposit a fraction of their kinetic energy as heat at the instantaneous surface of the growing moon. Rheology parameters are chosen to match those of ice I, although the satellites under consideration likely contain admixtures of lighter constituents. Consequences thereof are discussed. Thermal evolution calculations considering radiogenic heating by long-lived isotopes suggest that Ariel, Umbriel, Titania, Oberon and Charon may have started to differentiate after a few hundred million years of evolution. Results for Miranda - the smallest satellite of Uranus - however, indicate that it never convected or differentiated. Miranda's interior temperature was found to be not even close to the melting temperatures of reasonable mixtures of water and ammonia. This finding is in contrast to its heavily modified surface and supports theories that propose alternative heating mechanisms such as early tidal heating. Except for Miranda, our results lend support to differentiated icy satellite models. We also point out parallels to previously published results obtained for several of Saturn's icy satellites (Multhaup and Spohn, 2007). The predicted early histories of Ariel, Umbriel and Charon are evocative of Dione's and Rhea's, while Miranda's resembles that of Mimas.

Multhaup, K.; Spohn, T.

2007-08-01

426

Numerical analysis of flow and heat transfer in the VAFB LOX storage Dewar tank  

NASA Technical Reports Server (NTRS)

The present report describes numerical simulation of three-dimensional transient distributions of velocity and temperature of liquid oxygen (LOX) in the LOX Dewar tank of Vendenberg Air Force Base (VAFB). The present analyses cover the replenish time period only. Four test cases have been considered. For all four cases, the input boundary conditions are comprised of LOX facility heat loads, drain flow rates, recirculation flow rates and dewar heating. All the quantities are prescribed as functions of time. The first two test cases considered sensitivity of results to the computational grid. In Case 3, system heat load was changed, while in Case 4, a lower LOX level was specified. Cases 1 and 2 showed that the temperatures were not sensitive to the grid refinement. This provided a basic check on the numerical model. Cases 3 and 4 showed that the thermal boundary layer motion near the tank surface becomes more significant at the late time, e.g., 5 1/2 hours from replenish start. Comparison between results of Cases 3 and 4 showed, as expected, that the smaller initial LOX volume given in Case 4, results in higher temperature level. All calculated velocity and temperature distributions were found to be plausible.

Tam, L. T.; Singhal, A. K.

1984-01-01

427

Bellingham Phase 3, Engineering and technology development for a hot-water district-heating system employing thermal-energy storage  

NASA Astrophysics Data System (ADS)

Thermal energy storage in a district heating system which requires the integration of customer consumption rates, weather and other system operating conditions, as well as economic payback is evaluated. Generic methods of approaching and evaluating these factors are essential to insure that the most economical district heating projects are selected for development and that those systems are designed and operated in the most cost effective manner. Also, governmental and legal guidelines for interfacing with users, financing, and municipal utility regulations are examined

Vanroyen, G. L.

1981-11-01

428

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

SciTech Connect

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 act on this dilemma. Seemingly innocuous steel vessels buried throughout the land were recognized as a serious threat to human health and safety as groundwater supplied were jeopardized. In response, Congress passed Subtitle 1 as an amendment to RCRA. Last September, EPA issued regulations required by Congress under the law. States choosing to precede the new federal regulations established UST programs on their own, and began to register tanks and implement integrity-testing schedules.

Hayman, R. (Tank Tech Corp., Congers, NY (US))

1989-03-01

429

Hypereutectic heat storage alloy: Final report, Silicon shell integrity in molten Al-Si eutectic  

SciTech Connect

As a part of a program to evaluate the feasibility of using silicon encapsulated spheres of aluminum--silicon eutectic for thermal energy storage at temperatures near 650/degree/C, experiments were done to test the dimensional stability of the interface between silicon and the eutectic to thermal cycling. Cycled samples were sectioned and examined by optical micrography and by electron microscopy (SEM/EDX) techniques. Little or no degradation of the interface was observed at 600/degree/C (eutectic temperature 577/degree/C) while catastrophic degradation occurred at 700/degree/C. AT 650/degree/C interpenetration of 0.1/endash/0.2 mm was observed between the silicon and the eutectic alloys, with occasional larger (3/endash/4 mm) intrusions. 11 refs., 15 figs., 3 tabs.

Bennett, M.R.; Braunstein, J.

1988-06-01

430

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

431

Characterization of latent-heat-storage salts for use in rechargeable sodium/sulfur batteries  

SciTech Connect

The properties of candidate phase-change materials for use in a thermal management system for sodium/sulfur batteries were characterized. The experimental procedures used are presented along with a comprehensive description of the results. The principal properties were measured with differential scanning calorimetry and included heat-of-fusion and melting-point temperature. In addition, relevant thermal properties and compatibility with containment materials were studied. Recently, one of the salts studied was successfully incorporated into a prototype sodium/sulfur battery.

Armijo, J.R.

1994-05-01

432

Towards the development of latent heat storage electrodes for electroporation-based therapies  

NASA Astrophysics Data System (ADS)

Phase change materials (PCMs) capable of storing a large amount of heat upon transitioning from the solid-to-liquid state have been widely used in the electronics and construction industries for mitigating temperature development. Here, we show that they are also beneficial for reducing the peak tissue temperature during electroporation-based therapies. A numerical model is developed of irreversible electroporation (IRE) performed with hollow needle electrodes filled with a PCM. Results indicate that this electrode design can be utilized to achieve large ablation volumes while reducing the probability for thermal damage.

Arena, Christopher B.; Mahajan, Roop L.; Rylander, Marissa Nichole; Davalos, Rafael V.

2012-08-01

433

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

434

Enhancement of diffraction efficiency and storage life of poly(vinyl chloride)-based optical recording medium with incorporation of an electron donor  

NASA Astrophysics Data System (ADS)

The diffraction efficiency, sensitivity, and storage life of methylene blue-sensitized poly(vinyl chloride) film was improved by the addition of an electron donor in the matrix. The addition of pyridine enhanced the diffraction efficiency by two times, and storage life of the gratings was increased to 2-3 days.

John, Beena Mary; Ushamani, M.; Sreekumar, K.; Joseph, Rani; Sudha Kartha, C.

2007-01-01

435

Two Component Thermal Storage Material Study, Phase 2. Interim Progress Report, June 1976--December 1976.  

National Technical Information Service (NTIS)

A thermal storage medium of microsized capsules of a phase change material in a fluid offers the advantages of high heat capacity per unit volume and high rate of heat transfer to the phase change material. Several samples of Sunoco's P116 wax were encaps...

E. M. Mehalick A. T. Tweedie

1977-01-01

436

On-line heat flux measurements improve the culture medium for the growth and productivity of genetically engineered CHO cells  

Microsoft Academic Search

With the increasingly competitive commercial production of target proteins by hybridoma and genetically engineered cells,\\u000a there is an urgent requirement for biosensors to monitor and control on-line and in real time the growth of cultured cells.\\u000a Since growth is accompanied by an enthalpy change, heat dissipation measured by calorimetry could act as an index for metabolic\\u000a flow rate. Recombinant CHO

Yue H. Guan; Richard B. Kemp

1999-01-01

437

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 34°C continuously for a period of 5 d, or maintained at 24°C, on the same diets. 3. The control broilers exposed to 34°C showed decreased weight gain and feed consumption and slightly increased ROS production and malondialdehyde (MDA) concentrations in skeletal muscle. The chickens exposed to 34°C and supplemented with ERW showed significantly improved growth performance and lower ROS production and MDA contents in tissues than control broilers exposed to 34°C. 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

438

An Analysis of the Effect of Surface Heat Exchange on the Thermal Behavior of an Idealized Aquifer Thermal Energy Storage System  

NASA Astrophysics Data System (ADS)

Analytical expressions are derived for the temperature distribution and the mean temperature of an idealized aquifer thermal energy storage (ATES) system, taking into account the heat exchange at the ground surface and the finite thickness of the overlying layer above the storage aquifer. The analytical expressions for the mean temperature may be used to obtain rough estimates of first-cycle recovery factors for preliminary evaluations of shallow confined or unconfined ATES systems. The results, which are presented in nondimensional plots, indicate that surface heat exchange may have a significant influence on the thermal behavior of shallow ATES systems. Thus it is suggested that the effects of surface heat exchange should be considered carefully and included in the detailed analyses of such ATES systems.

Güven, O.; Melville, J. G.; Molz, F. J.

1983-06-01

439

Sulfur-containing compounds heated under alkaline condition: antibrowning, antioxidative activities, and their effect on quality of shrimp during iced storage.  

PubMed

Sulfur-containing compounds heated under alkaline condition (pH 10) were determined for inhibitory activity toward polyphenol oxidase (PPO) from Pacific white shrimp (Litopenaeus vannamei) and for antioxidative activity. Cysteine and glutathione (GSH) (20 mM) heated at 100 degrees C at pH 10 strongly inhibited PPO activity. Heated alkaline cysteine showed the greater 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activity, copper-chelating activity and reducing power than cysteine and glucose-cysteine Maillard reaction products (P < 0.05). Effect of heated alkaline cysteine at different concentrations (0, 20, and 100 mM) on the quality changes of Pacific white shrimp during iced storage was investigated. Shrimp treated with 100 mM heated alkaline cysteine had the lowest melanosis score, thiobarbituric acid-reactive substances (TBARS) value and total viable count (TVC), compared with those without treatment and treated with 20 mM heated alkaline cysteine, throughout the storage of 12 d (P < 0.05). Therefore, heated alkaline cysteine can be used as a novel additive to retard melanosis and extend the quality of postmortem shrimp. PMID:19723229

Phonpala, Yoottana; Benjakul, Soottawat; Visessanguan, Wonnop; Eun, Jong-Bang

2009-08-01

440

A thin diffuse component of the Galactic ridge X-ray emission and heating of the interstellar medium contributed by the radiation of Galactic X-ray binaries  

NASA Astrophysics Data System (ADS)

We predict a thin diffuse component of the Galactic ridge X-ray emission (GRXE) arising from the scattering of the radiation of bright X-ray binaries (XBs) by the interstellar medium. This scattered component has the same scale height as that of the gaseous disk (~80 pc) and is therefore thinner than the GRXE of stellar origin (scale height ~130 pc). The morphology of the scattered component is furthermore expected to trace the clumpy molecular and HI clouds. We calculate this contribution to the GRXE from known Galactic XBs assuming that they are all persistent. The known XBs sample is incomplete, however, because it is flux limited and spans the lifetime of X-ray astronomy (~50 years), which is very short compared with the characteristic time of 1000-10 000 years that would have contributed to the diffuse emission observed today due to time delays. We therefore also use a simulated sample of sources, to estimate the diffuse emission we should expect in an optimistic case assuming that the X-ray luminosity of our Galaxy is on average similar to that of other galaxies. In the calculations we also take into account the enhancement of the total scattering cross-section due to coherence effects in the elastic scattering from multi-electron atoms and molecules. This scattered emission can be distinguished from the contribution of low X-ray luminosity stars by the presence of narrow fluorescent K-? lines of Fe, Si, and other abundant elements present in the interstellar medium and by directly resolving the contribution of low X-ray luminosity stars. We find that within 1° latitude of the Galactic plane the scattered emission contributes on average 10 - 30% of the GRXE flux in the case of known sources and over 50% in the case of simulated sources. In the latter case, the scattered component is found to even dominate the stellar emission in certain parts of the Galactic plane. X-rays with energies ?1 keV from XBs should also penetrate deep inside the HI and molecular clouds, where they are absorbed and heat the interstellar medium. We find that this heating rate dominates the heating by cosmic rays (assuming a solar neighborhood energy density) in a considerable part of the Galaxy. Appendices are available in electronic form at http://www.aanda.org

Molaro, Margherita; Khatri, Rishi; Sunyaev, Rashid A.

2014-04-01

441

Two Component Thermal Storage Material. Semi-Annual Progress Report Covering the Period August 1, 1974--December 31, 1974.  

National Technical Information Service (NTIS)

This program is an experimental evaluation of the feasibility of a thermal energy storage medium consisting of a slurry of water and micro encapsulated spheres of paraffin. Such a medium combines the advantages of the heat capacity of phase change materia...

A. T. Tweedie E. M. Mehalick

1975-01-01

442

Preparation and characterization of novel anion phase change heat storage materials.  

PubMed

In this paper, polyurethane phase change material was successfully prepared with TDI with BDO for hard segments and PEG for soft segments. Moreover, based on this the solid-solid phase change material, A-PCM1030 which can release anions was prepared with the successful addition of anion additives A1030 for the first time. Then the test of the above material was conducted utilizing FT-IR, DSC, TEM, WAXD and Air Ion Detector. The Results indicated that the polyurethane phase change material possesses excellent thermal stability since there was no appearance of liquid leakage and phase separation after 50 times warming-cooling thermal cycles. It also presented reversibility on absorbing and releasing heat. In addition, adding a little A1030 can increase the thermal stability and reduce phase transition temperatures, as well as reduce the undercooling of the polyurethane phase change material. In addition, the anion test results suggested that the supreme amount of anion released by A-PCM1030 could reach 2510 anions/cm3 under dynamic conditions, which is beneficial for human health. PMID:24245138

Hong, Wei; Lil, Qingshan; Sun, Jing; Di, Youbo; Zhao, Zhou; Yu, Wei'an; Qu, Yuan; Jiao, TiFeng; Wang, Guowei; Xing, Guangzhong

2013-10-01

443

Radiant heat testing of the H1224A shipping/storage container  

SciTech Connect

H1224A weapons containers have been used for years by the Departments of Energy and Defense to transport and store W78 warhead midsections. Although designed to protect the midsections only from low-energy impacts, a recent transportation risk assessment effort has identified a need to evaluate the container`s ability to protect weapons in more severe accident environments. Four radiant heat tests were performed: two each on an H1224A container (with a Mk12a Mod 6c mass mock-up midsection inside) and two on a low-cost simulated H1224A container (with a hollow Mk12 aeroshell midsections inside). For each unit tested, temperatures were recorded at numerous points throughout the container and midsection during a 4-hour 121{degrees}C (250{degrees}F) and 30-minute 1010{degrees}C (1850{degrees}F) radiant environment. Measured peak temperatures experienced by the inner walls of the midsections as a result of exposure to the high-temperature radiant environment ranged from 650{degrees} C to 980{degrees} C (1200{degrees} F to 1800{degrees}F) for the H1224A container and 770 {degrees} to 990 {degrees}C (1420{degrees} F to 1810{degrees}F) for the simulated container. The majority of both containers were completely destroyed during the high-temperature test. Temperature profiles will be used to benchmark analytical models and predict warhead midsection temperatures over a wide range of the thermal accident conditions.

Harding, D.C.; Bobbe, J.G.; Stenberg, D.R.; Arviso, M.