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1

Research on medium and high temperature solar heat storage materials  

NASA Technical Reports Server (NTRS)

Characteristics of solar heat storage materials, preliminary tests in which melting and solidification characteristics are tested, and service life and cycling tests are reported. Various aspects of corrosion are discussed as well as decision about ultimate selection of materials. A program for storage and evaluation of data is included.

Heine, D.; Jucker, J.; Koch, D.; Krahling, H.; Supper, W.

1979-01-01

2

Natural convection along a heated vertical plate immersed in a nonlinearly stratified medium: application to liquefied gas storage  

NASA Astrophysics Data System (ADS)

We consider free convection driven by a heated vertical plate immersed in a nonlinearly stratified medium. The plate supplies a uniform horizontal heat flux to a fluid, the bulk of which has a stable stratification, characterized by a non-uniform vertical temperature gradient. This gradient is assumed to have a typical length scale of variation, denoted Z0, while 0, and the physical properties of the medium.We then apply the new theory to the natural convection affecting the vapour phase in a liquefied pure gas tank (e.g. the cryogenic storage of hydrogen). It is assumed that the cylindrical storage tank is subject to a constant uniform heat flux on its lateral and top walls. We are interested in the vapour motion above a residual layer of liquid in equilibrium with the vapour. High-precision axisymmetric numerical computations show that the flow remains steady for a large range of parameters, and that a bulk stratification characterized by a quadratic temperature profile is undoubtedly present. The application of the theory permits a comparison of the numerical and analytic results, showing that the theory satisfactorily predicts the primary dynamical and thermal properties of the storage tank.

Forestier, M.; Haldenwang, P.

3

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

4

Heating the warm ionized medium  

NASA Technical Reports Server (NTRS)

If photoelectric heating by grains within the diffuse ionized component of the interstellar medium is 10 exp -25 ergs/s per H atom, the average value within diffuse H I regions, then grain heating equals or exceeds photoionization heating of the ionized gas. This supplemental heat source would obviate the need for energetic ionizing photons to balance the observed forbidden-line cooling and could be responsible in part for enhanced intensities of some of the forbidden lines.

Reynolds, R. J.; Cox, D. P.

1992-01-01

5

Low temperature latent heat thermal energy storage - Heat storage materials  

Microsoft Academic Search

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

A. Abhat

1983-01-01

6

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

Microsoft Academic Search

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

SYUKRI HIMRAN; ARYADI SUWONO; G. ALI MANSOORI

1994-01-01

7

Heat storage technology update  

SciTech Connect

One way to reduce vehicle cold-start emissions of unburned fuel is to reduce catalyst light-off time. The U.S. Environmental Protection Agency (EPA) has evaluated several electrically heated catalyst (EHC) technologies with favorable results at ambient temperatures of 24C and [minus]7C. The resistive heating elements reduce the time during which the catalyst remains ineffective because of insufficient warming by the cold exhaust gas. Another way to reduce HC and CO emissions on cold starts is to shorten the time of fuel enrichment. If the engine reaches operating temperature sooner, enrichment to ensure good driveability may be correspondingly reduced. Schatz Thermo Engineering, Munich, Germany, has designed a device that stores excess heat energy from engine coolant for use at a later time. This heat battery described in this article stores thermal energy in a molten salt under vacuum. The salt then releases stored heat to cold engine coolant pumped through the heat battery. This warmed coolant can be pumped to locations within the vehicle to quickly warm the passenger compartment or engine.

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

1993-02-01

8

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

NASA Astrophysics Data System (ADS)

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

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

9

Magnesium oxide based heat storage device  

SciTech Connect

A cast magnesium oxide based structure is utilized as a heat storage material. In preferred embodiments, the magnesium oxide heat storage material is cast directly about a source of heat. In another embodiment, a block of cast magnesium oxide based heat storage material is placed in contact with a source of heat for raising the temperature and storing heat and later moved to a different environment for transferring heat to that environment.

Brosnan, D.A.

1982-08-10

10

A solar heating system with annual storage  

NASA Astrophysics Data System (ADS)

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

Lazzari, F.; Raffellini, G.

1981-07-01

11

Quantum heat engine with continuum working medium  

E-print Network

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

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

2006-07-18

12

Performance of chilled ceiling panels using phase change material slurries as the heat transport medium  

Microsoft Academic Search

Phase change materials (PCM) are advantageous for the dynamic and static storage of thermal energy. By encapsulating PCM in a solid material, of small enough diameter to be suspended in a liquid, partially melting and solidifying slurries can be created with very high energy densities and heat transfer rates. Such slurries are both transport medium and energy storage medium, and

P. W. Griffiths; P. C. Eames

2007-01-01

13

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

14

Ground heat storage with solar in Sweden  

SciTech Connect

Two experimental projects in Sweden, which are now using unusual forms of ground heat storage with solar energy, have led to more development in ground heat storage in Sweden. Two of the initial projects, which were funded by the Swedish government, are in operation near Kungsbacka, Sweden. Both utilize ground storage networks with either plastic piping and both are expected to provide energy savings payoffs within seven to nine years. The Lindalv School has a solar radiant heating system with ground storage in clay. The Djupedal School has buried its piping system in the peat which surrounds the school building. Another more recent project in Kullavik near Goteborg is designed for higher temperature ground heat storage. The paper describes the engineering of the ground heat systems and details some of the results after the first winter of operation.

Friedlander, A.F.; Olsson, S.

1983-08-01

15

Can Cosmic Rays Heat the Intergalactic Medium?  

E-print Network

Supernova explosions in the early star forming galaxies will accelerate cosmic rays (CRs). CRs are typically confined in the collapsed objects for a short period before escaping into the intergalactic medium (IGM). Galactic outflows can facilitate this escape by advecting CRs into the IGM. An outflow that results in a termination shock can also generate more CRs. We show that the CR protons from the above processes can significantly affect the thermal history of the IGM. Within plausible range of parameters, cosmic ray heating can compensate for adiabatic cooling and explain the measured IGM temperature at redshifts z between 2 to 4, even with early reionization.

Saumyadip Samui; Kandaswamy Subramanian; Raghunathan Srianand

2005-05-30

16

Can Cosmic Rays Heat the Intergalactic Medium?  

E-print Network

Supernova explosions in the early star forming galaxies will accelerate cosmic rays (CRs). CRs are typically confined in the collapsed objects for a short period before escaping into the intergalactic medium (IGM). Galactic outflows can facilitate this escape by advecting CRs into the IGM. An outflow that results in a termination shock can also generate more CRs. We show that the CR protons from the above processes can significantly affect the thermal history of the IGM. Within plausible range of parameters, cosmic ray heating can compensate for adiabatic cooling and explain the measured IGM temperature at redshifts z between 2 to 4, even with early reionization.

Samui, S; Srianand, R; Samui, Saumyadip; Subramanian, Kandaswamy; Srianand, Raghunathan

2005-01-01

17

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

18

Optimal sizing of biomass-fired Organic Rankine Cycle CHP system with heat storage  

Microsoft Academic Search

A novel methodology for Optimal Sizing of Biomass-Fired Organic Rankine Cycle (ORC) Combined Heat and Power (CHP) System with Heat Storage is presented in this paper. The ORC technology received a lot of attention recently, especially for medium scale applications (e.g. district heating) where market potential is substantial. Another push for the technology is provided in the context of recent

Gregor Taljan; Gregor Verbi?; Miloš Pantoš; Manfred Sakulin; Lothar Fickert

19

Aqueous heat-storage compositions containing fumed silicon dioxide and having prolonged heat-storage efficiencies  

SciTech Connect

Aqueous heat-storage compositions useful in space heating applications are disclosed which contain a phase-change material which absorbs and stores heat as it is heated above its phase change temperature and releases stored heat as it is cooled below its phase-change temperature. These compositions include fumed silicon dioxide which acts as a stabilizing agent and provides dramatically prolonged heat-storage efficiency for these compositions as they undergo repetitive cycling through their phase-change temperature. Articles containing such compositions and methods of forming such compositions are additionally disclosed.

Giuffrida, J.; Johnson, T.E.

1980-12-02

20

Advanced Heat Transfer and Thermal Storage Fluids  

SciTech Connect

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

Moens, L.; Blake, D.

2005-01-01

21

Ammonia as a hydrogen energy-storage medium  

NASA Astrophysics Data System (ADS)

Liquid Hydrogen (LH2), Methanol (MeOH), and Ammonia (NH3) are compared as hydrogen energy-storage media on the basis of reforming the MeOH to produce H2 and dissociating (cracking) the NH3 to release H2. The important factors in this storage concept are discussed. It is shown that, in terms of energy input for media manufacture from natural gas, hydrogen energy content of the medium, and energy cost NH3 has a wide advantage and comes the closest to matching gasoline. The tasks required in developing a safe and practical hydrogen energy-storage system based on the storage and cracking of NH3 are listed.

Strickland, G.

1981-03-01

22

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

23

Central solar heating plants with seasonal storage  

SciTech Connect

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

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

1992-05-01

24

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

25

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

26

Central solar heating plants with seasonal storage  

SciTech Connect

The University of Massachusetts has recently started a two year effort to identify and design a significant Central Solar Heating Plant with Seasonal Storage (CSHPSS) in Massachusetts. The work is closely associated with the U.S. participation in the International Energy Agency (IEA) Task on CSHPSS. The University is working closely with the Commonwealth of Massachusetts to assist in identifying State facilities as potential sites and to explore and secure State support which will be essential for product development after the design phase. Currently, the primary site is the University of Massachusetts, Amherst campus with particular interest in several large buildings which are funded for construction over the next 4-5 years. Seasonal thermal energy storage will utilize one of several geological formations.

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

1989-03-01

27

Medium energy ion implantation of Germanium into heated Silicon  

E-print Network

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

McCoy, John Curtis

2012-06-07

28

CalHEAT Research and Market Transformation Roadmap for Medium  

E-print Network

CalHEAT Research and Market Transformation Roadmap for Medium and Heavy Duty Trucks Delivering President CALSTART #12;California Hybrid, Efficient and Advanced Truck Research Center What is CalHEAT? ­ State center for research, development, demonstration and commercialization of advanced, efficient truck

California at Davis, University of

29

Thermal storage technologies for solar industrial process heat applications  

NASA Technical Reports Server (NTRS)

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

Gordon, L. H.

1979-01-01

30

Catalytic combustion of actual low and medium heating value gases  

NASA Technical Reports Server (NTRS)

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

Bulzan, D. L.

1982-01-01

31

Solar heat storages in district heating Klaus Ellehauge Thomas Engberg Pedersen  

E-print Network

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

32

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

33

Evaluation of solar heating systems with seasonal storage in New England. Systems using duct storage in rock and heat pump  

Microsoft Academic Search

This Evaluation focuses on the New England region of the United States, and considers seasonal storage of solar energy using duct storage in rock and a heat pump. Adequate bedrock for large scale storage is available in the New England region and the climate, which includes cold, relatively cloudy winters and summers with substantial insolation, makes seasonal storage technology of

D. S. Breger; A. I. Michaels

1985-01-01

34

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

35

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

Microsoft Academic Search

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

Satoru Okamoto

2006-01-01

36

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

37

Hydromagnetic wave heating of the low-density interstellar medium  

NASA Technical Reports Server (NTRS)

A simple model for supernova remnant sources of MHD waves is used to calculate the energy spectrum of waves in the intercloud medium and the heating rate resulting from their dissipation. Models of thermal phases of interstellar gas in ionization and thermal equilibrium are then constructed, and it is demonstrated that wave dissipation can be an important heating mechanism which can account for the observed high H I temperatures in low-density (intercloud) neutral gas.

Ferriere, Katia M.; Zweibel, Ellen G.; Shull, J. Michael

1988-01-01

38

Method and apparatus for heat storage in internal combustion engines  

Microsoft Academic Search

Exhaust emissions are reduced, fuel consumption is improved for internal-combustion engines, and the number of cold starts reduced by storing heat energy from the operation of the engine in a heat-storage reservoir filled with a change-of-state heat-storage material. Absorbed heat energy is released back to the engine's intake manifold to maintain elevated engine temperature between uses and starting up of

Lindberg

1983-01-01

39

Solar-assisted heat pump systems and energy storage  

Microsoft Academic Search

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

K. Kaygusuz; Oe. Comakli; T. Ahyan

1991-01-01

40

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

41

Thermal energy storage for industrial waste heat recovery  

NASA Technical Reports Server (NTRS)

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

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

1978-01-01

42

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

E-print Network

ICEBO2006, Shenzhen, China Renewable Energy Resources and a Greener Future Vol.VIII-2-2 Preliminary Analysis of a Solar Heat Pump System with Seasonal Storage for Heating and Cooling Guoqing Yu Peng Chen...---Status Report[M], IEA Technical Report, 1990. [2] Peng Chen. Preliminary Study of Solar Heating and cooling Systems with Seasonal Storage[D]. Shanghai: University of Shanghai for Science and Technology, 2006. [3] T.Schmidt, et al. Central solar heating...

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

2006-01-01

43

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

NASA Technical Reports Server (NTRS)

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

Saha, H.

1981-01-01

44

Transient behavior of heat pipe with thermal energy storage under pulse heat loads  

Microsoft Academic Search

Future space missions will require thermal transport devices with the ability to handle transient pulse heat loads. A novel design of a high-temperature axially grooved heat pipe (HP) which incorporates thermal energy storage (TES) to migrate pulse heat loads was presented. A phase-change material (PCM) which is encapsulated in cylindrical containers was used for the thermal energy storage. The transient

Ming-Chang Jr.

1991-01-01

45

Chemical heat pump and chemical energy storage system  

DOEpatents

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

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

1985-08-06

46

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

NASA Technical Reports Server (NTRS)

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

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

1977-01-01

47

Direct contact heat exchanger for phase change thermal storage  

Microsoft Academic Search

A molten salt-to-liquid metal direct contact heat exchanger is being developed for phase change thermal storage in central receiver solar thermal plants. The heat exchanger consists of a column of liquid metal into which molten salt is injected. Salt droplets that form at the injector orifices rise through the column and solidify as they transfer heat to the liquid metal.

W. Luft; J. W. Leach; T. Lowry

1984-01-01

48

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

SciTech Connect

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

None

2012-01-01

49

Intermediate temperature, heat storage and retrieval system  

Microsoft Academic Search

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

Greene

1980-01-01

50

Heating of the intergalactic medium due to structure formation  

E-print Network

We estimate the heating of the intergalactic medium due to shocks arising from structure formation. Heating of the gas outside the collapsed regions, with small overdensities (${n_b \\over {\\bar n_b}}\\ll 200$) is considered here, with the aid of Zel'dovich approximation. We estimate the equation of state of this gas, relating the density with its temperature, and its evolution in time, considering the shock heating due to one-$\\sigma$ density peaks as being the most dominant. We also estimate the mass fraction of gas above a given temperature as a function of redshift. We find that the baryon fraction above $10^6$ K at $z=0$ is $\\sim 10 %$. We estimate the integrated Sunyaev-Zel'dovich distortion from this gas at present epoch to be of order $10^{-6}$.

Biman Nath; Joseph Silk

2001-07-20

51

Intermediate temperature, heat storage and retrieval system  

SciTech Connect

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

Greene, N.D.

1980-10-14

52

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

53

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

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

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

54

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

55

Flow and cold heat-storage characteristics of phase-change emulsion in a coiled double-tube heat exchanger  

Microsoft Academic Search

This paper dealt with the flow and cold heat-storage characteristics of the oil (tetradecane, CââHââ, freezing point 278.9 K)\\/water emulsion as a latent heat-storage material having a low melting point. A coiled double-tube heat exchanger was used for the cold heat storage experiment. The pressure drop, the heat transfer coefficient, and the finishing time of cold heat storage in the

H. Inaba; S. Morita

1995-01-01

56

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

Microsoft Academic Search

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

M. Costa; D. Buddhi; A. Oliva

1998-01-01

57

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

58

Low and medium heating value coal gas catalytic combustor characterization  

NASA Astrophysics Data System (ADS)

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.

1982-11-01

59

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

60

Improved Heat-of-Fusion Energy Storage  

NASA Technical Reports Server (NTRS)

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

Chen, K. H.; Manvi, R.

1982-01-01

61

A comparative performance study of some thermal storage materials used for solar space heating  

Microsoft Academic Search

One of the most common methods used in passive heating is the utilization of a massive wall for heat storage. Many factors affect the performance of the wall, such as the thickness and the media used for heat storage. A numerical study has been conducted on a zone heated by a thermal storage wall. Three different storage materials are examined,

Abdul Jabbar N. Khalifa; Ehsan F. Abbas

2009-01-01

62

Rapid Charging of Thermal Energy Storage Materials through Plasmonic Heating  

PubMed Central

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

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

2014-01-01

63

Rapid Charging of Thermal Energy Storage Materials through Plasmonic Heating  

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

64

Rapid charging of thermal energy storage materials through plasmonic heating.  

PubMed

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

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

2014-01-01

65

The evolution of a pre-heated Intergalactic Medium  

E-print Network

We analyse the evolution of the Intergalactic Medium (IGM) by means of an extended set of large box size hydrodynamical simulations which include pre-heating. We focus on the properties of the z~2 Lyman-alpha forest and on the population of clusters and groups of galaxies at z=0. We investigate the distribution of voids in the Lyman-alpha flux and the entropy-temperature relation of galaxy groups, comparing the simulation results to recent data from high-resolution quasar spectra and from X-ray observations. Pre-heating is included through a simple phenomenological prescription, in which at z=4 the entropy of all gas particles, whose overdensity exceeds a threshold value delta_h is increased to a minimum value K_fl. While the entropy level observed in the central regions of galaxy groups requires a fairly strong pre-heating, with K_fl>100 keV cm^2, the void statistics of the Lyman-alpha forest impose that this pre-heating should take place only in relatively high-density regions, in order not to destroy the cold filaments that give rise to the forest. We conclude that any injection of non-gravitational energy in the diffuse baryons should avoid low-density regions at high redshift and/or take place at relatively low redshift.

S. Borgani; M. Viel

2008-10-18

66

Heat storage for a bus petrol internal-combustion engine  

Microsoft Academic Search

The heat storage (HS) system for pre-heating a bus petrol internal combustion engine to starting was mathematically modelled\\u000a and experimentally investigated. The development of such devices is an extremely urgent problem especially for regions with\\u000a a cold climate. We discuss how HS works on the effect of absorption and rejection of heat energy at a solid-liquid phase change\\u000a of a

Leonard L. Vasiliev; Victor S. Burak; Andry G. Kulakov; Donatas A. Mishkinis; Pavel V. Bohan

67

Central solar heating plants with seasonal storage  

Microsoft Academic Search

Every year, the United States uses approximately 15 quads of energy (26 quads of primary fuels) to heat buildings and water for domestic use. Applying solar energy to these loads is attractive because of the low-temperature requirements of the end-uses. However, past solar approaches to space heating in cold winter climates have not fared well technically or economically because the

D. S. Breger; J. E. Sunderland; C. A. Bankston

1992-01-01

68

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

69

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

70

Central solar heating plants with seasonal storage. Evaluation of systems concepts based on heat storage in aquifers  

Microsoft Academic Search

The work undertaken by the aquifer seasonal thermal energy storage team from the USA and Canada is documented. The analytic effort was divided between heat pump systems and systems without heat pumps. The aquifer based system configurations that were analyzed are defined, and the approach and methodology employed in this analysis are outlined. Principal results are presented in terms of

V. G. Chant; D. S. Breger

1984-01-01

71

[Viability of Malassezia pachydermatis strains maintained in various storage mediums].  

PubMed

The maintenance of Malassezia pachydermatis in fungal collections is very important for retrospective and prospective studies. The aim of this study was to evaluate the behavior of Malassezia pachydermatis in different storage methods. After the identification process, M. pachydermatis strains were stored for six and nine months, in saline and saline plus mineral oil at 28 degrees C, as well as in Dixon's agar, Dixon's agar plus glycerol and Dixon's agar plus dimethyl-sulfoxide (DMSO), at -20 degrees C. Dixon's agar and Dixon's agar plus glycerol were the most adequate methods (p < 0.05) for the maintenance of Malassezia pachydermatis viability, after six and nine months of storage. All the methods used were capable of maintaining the urease activity at six months of storage, but only Dixon's agar and Dixon's agar plus glycerol were statistically adequate at nine months (p < 0.05). Thus, to assure Malassezia pachydermatis recovery and to maintain its characteristics, Dixon's agar or Dixon's agar plus glycerol should be used. PMID:15330062

Girão, Marília Dutra; do Prado, Marilena Ribeiro; Brilhante, Raimunda Sâmia Nogueira; Cordeiro, Rossana Aguiar; Monteiro, André Jalles; Sidrim, José Júlio Costa; Rocha, Marcos Fábio Gadelha

2004-01-01

72

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

Microsoft Academic Search

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

Zhongliang Liu; Zengyi Wang; Chongfang Ma

2006-01-01

73

The CMU air-core passive hybrid heat storage system  

SciTech Connect

This paper discusses environmental engineering and practical application of the concrete masonry unit (CMU) based air-core thermal storage system, principally applied in climate responsive (passive and hybrid solar) building design. CMU's with their large core spaces can provide ample heat-transfer surface areas near low-velocity air-flows conducted through stacked masonry units where the cores are aligned as ducts. CMU air-core heat storage is ideally suited to the low-cost application of thermal storage in the structural envelope of buildings. The physical principals of designing, analyzing and predicting performance of these systems are reviewed. Sample building performance assessments are provided along with heat transfer properties information on such CMU systems, derived from both field measurements and engineering calculations. Generic design diagrams are provided based on actual built projects.

Howard, B.D.

1999-07-01

74

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

75

(Cooperative effort of research in latent heat thermal energy storage)  

SciTech Connect

The traveler spent the period July 27--September 30th on site at Ben Gurion University in Beersheeba. During this time he pursued a cooperative effort of research in latent heat thermal energy storage with members of the Chemical Engineering Department of the University; examined problems associated with hyperbolic heat transfer with researchers at Tel Aviv University; and worked on mathematical questions related to moving boundary problems, and simulation and artificial intelligence.

Solomon, A.D.

1987-10-15

76

Evaluation of solar heating systems with seasonal storage in New England. Systems using duct storage in rock and heat pump  

SciTech Connect

This Evaluation focuses on the New England region of the United States, and considers seasonal storage of solar energy using duct storage in rock and a heat pump. Adequate bedrock for large scale storage is available in the New England region and the climate, which includes cold, relatively cloudy winters and summers with substantial insolation, makes seasonal storage technology of particular interest. This analysis has been performed within the context of the International Energy Agency, Solar Heating and Cooling Program, Task VII on Central Solar Heating Plants with Seasonal Storage (CSHPSS). The general results of the analysis indicate that the optimized systems provide 75 to 80% of the low temperature demand load and 60 to 65% of the high temperature demand load with solar energy, with the remaining portion coming primarily from the heat pump electrical input energy. The annualized cost of the energy supplied by the system to the distribution network using the base case economic scenario is $44 to 52/MWH and $58 to 62/MWH for the low and high temperature loads, respectively. Significant reductions in cost are found when systems are financed with present incentives provided by the federal government. These results are encouraging in terms of the system cost-effectiveness relative to energy costs in the New England area which are comparable to these values.

Breger, D.S.; Michaels, A.I.

1985-01-01

77

A Direct Method for Measuring Heat Conductivity in Intracluster Medium  

E-print Network

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

Makoto Hattori; Nobuhiro Okabe

2005-02-09

78

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

Microsoft Academic Search

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

Zhongliang Liu; Zengyi Wang; Chongfang Ma

2006-01-01

79

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

80

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

81

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

82

Wallboard with latent heat storage for passive solar applications  

Microsoft Academic Search

Conventional wallboard impregnated with octadecane paraffin is being developed as a building material with latent heat storage for passive solar and other applications. Impregnation was accomplished simply by soaking the wallboard in molten wax. Concentrations of wax in the combined product as high as 35% by weight can be achieved. Scale-up of the soaking process, from small laboratory samples to

Kedl

1991-01-01

83

Conventional Wallboard With Latent Heat Storage For Passive Solar Applications  

Microsoft Academic Search

Conventional wallboard impregnated with octadecane paraffin (Melting Point - 73.50F) is being developed as a building material with latent heat storage for passive solar applications. Impregnation was accomplished simply by soaking the wallboard in molten paraffin. Concentrations of paraffin in the combined product as high as 35% by weight were achieved. In support of this concept, a computer model was

R. J. Kedl

1990-01-01

84

Computational heat transfer modeling of thermal energy storage canisters  

Microsoft Academic Search

A computer code has been developed for analyzing the phenomena occurring in cylindrical metal canisters containing a high temperature Phase Change Material (PCM). Such canisters are normally used as thermal storage elements in heat receivers of solar dynamic power systems for low orbit space vehicles. The code will be a useful canister design tool and it is able to predict

Pavel Alexandrovich Sokolov

1997-01-01

85

Heat storage system utilizing phase change materials government rights  

Microsoft Academic Search

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

Salyer; Ival O

2000-01-01

86

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

87

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

88

Transient behavior of heat pipe with thermal energy storage under pulse heat loads  

NASA Astrophysics Data System (ADS)

Future space missions will require thermal transport devices with the ability to handle transient pulse heat loads. A novel design of a high-temperature axially grooved heat pipe (HP) which incorporates thermal energy storage (TES) to migrate pulse heat loads was presented. A phase-change material (PCM) which is encapsulated in cylindrical containers was used for the thermal energy storage. The transient response of the HP/TES system under two different types of pulse heat loads was studied analytically. The first type is pulse heat loads applied at the heat pipe evaporator, the second type is reversed-pulse heat loads applied at the condenser. In this research, a new three-dimensional alternating-direction-implicit (ADI) method was developed to model the heat conduction through the heat pipe wall and wicks, including the liquid flow in grooves. A very important characteristic of this new ADI method is that it is consistent with physical considerations. Compared with the well-known Brian's and Douglas's ADI methods, this new ADI method had higher accuracy and requires less computer storage. In the numerical solution of heat transfer problems with phase change (Stefan-type problem), a modified Pham's method which includes features from enthalpy and heat capacity methods was used to simulate the melting and solidification processes of the PCG. The vapor flow was assumed quasi-steady and one-dimensional, and was coupled with the evaporation and condensation on the heat pipe inside wall surface and the surfaces of the PCM containers. The transient responses of three different HP/TES configurations were compared: (1) a heat pipe with a large empty cylinder installed in the vapor core, (2) a heat pipe with a large PCM cylinder, and (3) a heat pipe with six small PCM cylinders. From the numerical results, it was found that the PCM is very effective in mitigrating the adverse effect of pulse heat loads. The six small PCM cylinders are more efficient than the large PCM cylinder in relaxing the heat pipe temperature increase under pulse heat loads. Also, the small PCM cylinders can handle periodic, pulse heat loads better because the small PCM cylinders can solidify faster after each periodic, pulse heat load is terminated. A simple lumped-heat-capacity model was also used to predict the transient behavior of the heat pipe without PCM. Compared with the results from the finite-difference solution, it was found that the lumped model can predict the average heat pipe temperature and the heat input/output as the evaporator and condenser for the heat pipe without PCM quite well.

Chang, Ming-, Jr.

1991-02-01

89

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

NASA Astrophysics Data System (ADS)

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

Ünalan, Sebahattin; Özrahat, Evrim

2014-08-01

90

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

NASA Astrophysics Data System (ADS)

Possible heat storage methods for a temperature range from 200 to 500 C are reviewed to obtain higher specific heat content and to work at lower pressures. Three possible storage methods: sensible heat, latent heat or reversible chemical reactions, are reviewed. The thermodynamic quality and the efficiency of the storage system are defined. The material resistance, the cost, the thermodynamic quality, and the maintenance problems of the heat storage systems are discussed. Physical characteristic figures of possible heat storage materials are given. The various storage techniques are assesed with respect to thermal power plant applications. A thermal and cost analysis was carried out for oil/solid, molten salt/solid, or latent heat storage systems. Storage in oil or in the combination oil/solid material must be considered as an alternative to hot water storage.

Steiner, D.; Heine, D.; Nonnenmacher, A.

1982-07-01

91

Solar-assisted heat pump and energy storage for residential heating  

Microsoft Academic Search

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

O. Comakli; K. Kaygusuz; T. Ayhan

1993-01-01

92

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

93

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

E-print Network

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

Saxe, Shoshanna Dawn

2009-01-01

94

Heat pipe cooling system for underground, radioactive waste storage tanks  

SciTech Connect

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

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

1980-02-01

95

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

96

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

97

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

98

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

99

Laser-induced heating of a multilayered medium resting on a half-space: Part 2 - Moving source  

SciTech Connect

Direct access storage devices (DASDs) are widely used in the computer industry to store and manage data. In conventional magnetic recording, an induction head flying very close to the disk surface alters the polarization of the magnetic field of the disk surface to erase and or write the information on the disk. However, a new technology known as magneto optical recording or optical recording has considerable promise to increase data densities and reliability of data source. In magneto-optical storage, magnetic fields are altered by a laser source, which heats the magnetic medium beyond its Curie point, a temperature at which the magnetic medium loses its magnetization. This domain with zero magnetization is subsequently reversed by using an induction magnet. All these processes take place when the disk is rotating at a very high speed with respect to the laser source. An optical disk is a multilayered medium consisting of a thick glass disk on which many layers of different materials are sputtered, only one layer of which serves as a magnetic medium. Therefore, in this paper, a problem of laser-induced heating of a multilayered medium resting on a half-space is considered when the laser is translation with respect to it. The transient heat conduction equation is solved by employing the Laplace transform in the time domain and the Fourier Transform in the x, y dimension. The resulting ordinary differential equation is solved and the inversion of the Lapplace transform is obtained by a technique developed by Crump. The Fourier inversion is obtained by using a Fast Fourier Transform. The technique developed here is then applied to calculate domain size for recorded bits for a given disk, laser power, source characteristics, and rotational velocity.

Kant, R.; Deckert, K.L. (IBM Research Div., San Jose, CA (USA))

1991-02-01

100

Wallboard with Latent Heat Storage for Passive Solar Applications  

Microsoft Academic Search

Conventional wallboard impregnated with octadecane paraffin [melting point-23 C (73.5 F)] is being developed as a building material with latent heat storage for passive solar and other applications. Impregnation was accomplished simply by soaking the wallboard in molten wax. Concentrations of wax in the combined product as high as 35% by weight can be achieved. Scale-up of the soaking process,

Kedl

2001-01-01

101

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

102

Integrated heat exchanger design for a cryogenic storage tank  

SciTech Connect

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.; Bonner, T.; Oliveira, J. M.; Johnson, W. L.; Notardonato, W. U. [NASA Kennedy Space Center, Cryogenics Test Laboratory, NE-F6, KSC, FL 32899 (United States); Tomsik, T. M. [NASA Glenn Research Center, 21000 Brookpark Road, Cleveland, OH 44135 (United States); Conyers, H. J. [NASA Stennis Space Center, Building 3225, SSC, MS 39529 (United States)

2014-01-29

103

Central solar heating plants with seasonal storage. Evaluation of systems concepts based on heat storage in aquifers  

SciTech Connect

The work undertaken by the aquifer seasonal thermal energy storage team from the USA and Canada is documented. The analytic effort was divided between heat pump systems and systems without heat pumps. The aquifer-based system configurations that have been analyzed are defined, and the approach and methodology employed in this analysis are outlined. Principal results are presented in terms of optimum designs for reference cases, and sensitivity results around the reference cases for selected variables. Characteristics of system designs are given for a wide range of key design parameters. Finally, a detailed list of system parameter values and more detailed results of the analysis are presented. (LEW)

Chant, V.G.; Breger, D.S.

1984-10-01

104

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

Microsoft Academic Search

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

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

1999-01-01

105

SELF-REGULATING SUPERNOVA HEATING IN INTERSTELLAR MEDIUM SIMULATIONS  

E-print Network

-phase interstellar medium have been carried out, using a 3D,nonlinear,magnetohydrodynamic,shearing disc. For similar rea- sons of computational resolution, none attempt to model all of the phases of gas

Brandenburg, Axel

106

Assessment of solar heating systems with seasonal storage in New England: systems using duct storage in rock and a heat pump  

Microsoft Academic Search

This report assesses seasonal storage of solar energy for the New England region, using duct storage in rock and a heat pump. The winter climate in New England requires large heating loads, and the winter insolation is inadequate for significant solar contributions from diurnal or passive systems. The abundant solar energy available during the remainder of the year could be

D. S. Breger; A. I. Michaels

1985-01-01

107

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. PMID:19333448

Felderhoff, Michael; Bogdanovi?, Borislav

2009-01-01

108

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

109

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

Microsoft Academic Search

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

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

1979-01-01

110

Current status of ground source heat pumps and underground thermal energy storage in Europe  

Microsoft Academic Search

Geothermal Heat Pumps, or Ground Coupled Heat Pumps (GCHP), are systems combining a heat pump with a ground heat exchanger (closed loop systems), or fed by ground water from a well (open loop systems). They use the earth as a heat source when operating in heating mode, with a fluid (usually water or a water–antifreeze mixture) as the medium that

Burkhard Sanner; Constantine Karytsas; Dimitrios Mendrinos; Ladislaus Rybach

2003-01-01

111

Central unresolved issues in thermal energy storage for building heating and cooling  

SciTech Connect

This document explores the frontier of the rapidly expanding field of thermal energy storage, investigates unresolved issues, outlines research aimed at finding solutions, and suggests avenues meriting future research. Issues related to applications include value-based ranking of storage concepts, temperature constraints, consistency of assumptions, nomenclature and taxonomy, and screening criteria for materials. Issues related to technologies include assessing seasonal storage concepts, diurnal coolness storage, selection of hot-side storage concepts for cooling-only systems, phase-change storage in building materials, freeze protection for solar water heating systems, and justification of phase-change storage for active solar space heating.

Swet, C.J.; Baylin, F.

1980-07-01

112

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

113

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

114

Study of thermal energy storage using fluidized bed heat exchangers  

SciTech Connect

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

115

Transient coupled heat transfer in a rectangular medium with black surfaces  

Microsoft Academic Search

The main objective of this paper is to extend to two-dimensional (2-D) medium the ray tracing-node analyzing method, which has already been successfully used to solve one-dimensional (1-D) problem of coupled heat transfer in a semitransparent medium. For simplicity, an infinitely long rectangular semitransparent medium with four black opaque surfaces is chosen as our studying object. A control volume method

Jian-Feng Luo; Sheng-Li Chang; Jian-Kun Yang; Xi Shen; Garba inoussa

2008-01-01

116

Thermal energy storage systems using fluidized bed heat exchangers  

SciTech Connect

The purpose of this study was to conduct a technical and economical assessment of the use of fluid bed heat exchangers (FBHX) for Thermal Energy Storage (TES) in applications having potential for waste heat recovery. A large number of industrial processes and solar power generation were considered to determine the applicability of a FBHX for TES. The potential applications were grouped on a unit operations basis so that if the system was applicable to one industry it may also be adaptable to other industries having similar unit operations. The rotary cement kiln and the electric arc furnace were chosen for evaluation using a variety of screening criteria. Numerous potential FBHX configurations were evaluated to identify the most effective types for TES systems and ranked according to operating parameters such as efficiency of heat recovery, heat transfer rate, system pressure drop, environmental problems, stability of bed operation, etc. In order to maximize the system's effectiveness while minimizing parasitic power requirements, multistage shallow bed FBHX's operating with high temperature differences were identified as the most suitable for TES applications. The technical feasibility of FBHX for TES systems has been verified by analysis of the two selected conceptual systems. Each technical evaluation 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 times, and parasitic power required for operation.

Weast, T.; Shannon, L.

1980-06-01

117

Seasonal storage solar heating system for the Charlestown, Boston Navy Yard National Historic Park  

Microsoft Academic Search

This paper concerns the design and analysis of a solar energy system using seasonal heat storage for the National Historic Park in the Charlestown Navy Yard, Boston, Massachusetts. The system uses two existing underground concrete storage tanks filled with water as the heat store and makes use of an existing tunnel network for placement of the heat distribution pipe network.

D. S. Breger; A. I. Michaels

1984-01-01

118

Fatty Acid\\/Expanded Graphite Composites as Phase Change Material for Latent Heat Thermal Energy Storage  

Microsoft Academic Search

The fatty acid\\/expanded graphite (EG) composites as phase change material (PCM) for latent heat thermal energy storage were prepared by means of vacuum impregnation method and their thermal properties and heat charging\\/discharging characteristics were determined. In the composites, the fatty acids (capric, lauric, and myristic acids) act as a phase change latent heat storage material, and the EG serves like

A. Sari; A. Karaipekli; K. Kaygusuz

2008-01-01

119

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

Microsoft Academic Search

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

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

1988-01-01

120

Exergy analysis of ice storage air-conditioning system with heat pipe during charging period  

Microsoft Academic Search

The ice storage air-conditioning system with heat pipe was presented, and analytical model relating to the exergy loss amount and loss rate was developed in each component of the ice storage air-conditioning system. Exergy analysis results of the ice storage air-conditioning system with heat pipe were compared with those of the ice storage air-conditioning system with ice-on-coil. The energy saving

Guiyin Fang; Xu Liu

2010-01-01

121

Effects of preincubation heating of broiler hatching eggs during storage, flock age, and length of storage period on hatchability.  

PubMed

The effects of heating of eggs during storage, broiler breeder age, and length of egg storage on hatchability of fertile eggs were examined in this study. Eggs were collected from Ross 344 male × Ross 308 broiler breeders on paper flats, held overnight (1 d) at 18°C and 75% RH, and then transferred to plastic trays. In experiment 1, eggs were obtained at 28, 38, and 53 wk of flock age. During a further 10 d of storage, eggs either remained in the storage room (control) or were subjected to a heat treatment regimen of 26°C for 2 h, 37.8°C for 3 h, and 26°C for 2 h in a setter at d 5 of storage. In experiment 2, eggs from a flock at 28 wk of age were heated for 1 d of a 6-d storage period. Eggs from a 29-wk-old flock were either heated at d 1 or 5 of an 11-d storage period in experiment 3. In experiment 4, 27-wk-old flock eggs were heated twice at d 1 and 5 of an 11-d storage period. Control eggs stored for 6 or 11 d were coincubated as appropriate in each experiment. Heating eggs at d 5 of an 11-d storage period increased hatchability in experiment 1. Although no benefit of heating 28-wk-old flock eggs during 6 d of storage in experiment 2 was observed, heating eggs from a 29-wk-old flock at d 1 or 5 of an 11-d storage period increased hatchability in experiment 3. Further, heating eggs from a 27-wk-old flock twice during 11 d of storage increased hatchability in experiment 4. These effects were probably due to the fact that eggs from younger flocks had been reported to have many embryos at a stage of development where the hypoblast had not yet fully developed (less than EG-K12 to EG-K13), such that heating during extended storage advanced these embryos to a more resistant stage. PMID:24235243

Gucbilmez, M; Ozlü, S; Shiranjang, R; Elibol, O; Brake, J

2013-12-01

122

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

123

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

Microsoft Academic Search

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

M. Lazard; S. Andre; D. Maillet

2001-01-01

124

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

125

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

NASA Astrophysics Data System (ADS)

SummaryTwo 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.

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

2012-02-01

126

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

Microsoft Academic Search

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

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

2007-01-01

127

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

128

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

E-print Network

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

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

1980-01-01

129

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

E-print Network

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

Bjorklund, Abbe Ellen

1986-01-01

130

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

131

An analytical study of heat exchanger effectiveness and thermal performance in a solar energy storage system with PCM  

Microsoft Academic Search

Solar thermal energy storage systems can be categorized based on materials that store either as sensible heat or as latent heat of fusion. For convenience, the latter are designated as phase change materials (PCM). It is a fairly well accepted fact that PCM storage devices usually require less storage volume. In a recent paper, heat exchanger effectiveness for PCM storage

J. C. Y. Wang; C. C. K. Kwok; S. Lin; G. H. Vatistas

1984-01-01

132

Pulse mitigation and heat transfer enhancement techniques. Volume 4: Transient behavior of heat pipe with thermal energy storage under pulse heat loads  

Microsoft Academic Search

A novel design of a high-temperature axially grooved heat pipe (HP), which utilizes thermal energy storage (TES) to mitigate pulse heat loads, was presented. Phase-change material (PCM) encapsulated in cylindrical containers was used for thermal energy storage. The transient responses of the HP\\/TES system under two types of pulse heat loads were studied numerically. The first type is pulse heat

L. C. Chow; M. J. Chang

1992-01-01

133

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

Microsoft Academic Search

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

Viorel Badescu

2003-01-01

134

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

135

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

136

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

E-print Network

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

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

2006-01-01

137

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

Microsoft Academic Search

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

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

2008-01-01

138

Discontinuous finite element method for radiative heat transfer in semitransparent graded index medium  

Microsoft Academic Search

To avoid the complicated and time-consuming computation of curved ray trajectories, a discontinuous finite element method based on discrete ordinate equation is extended to solve the radiative transfer problem in a multi-dimensional semitransparent graded index medium. Two cases of radiative heat transfer in two-dimensional rectangular gray semitransparent graded index medium enclosed by opaque boundary are examined to verify this discontinuous

L. H. Liu; L. J. Liu

2007-01-01

139

Mild heat and calcium treatment effects on fresh-cut cantaloupe melon during storage  

Microsoft Academic Search

The effect of mild heat fruit pre-treatment on some properties of fresh-cut cantaloupe melon during storage was determined. Whole fruit, previously held at 4°C, was immersed in heated water (60°C) with and without dissolved calcium lactate (1%). Fresh-cut processing was done immediately, either after treatment or after storage at 4°C for 24h. Headspace gas accumulation during storage indicated reduced respiration

Olusola Lamikanra; Michael A. Watson

2007-01-01

140

[Expression of heat-labile enterotoxin and the strategy of purification and storage].  

PubMed

Heat-labile enterotoxin (LT) from Escherichia coli is a bacterial protein toxin with an AB5 hexamer structure. LT is a powerful mucosal adjuvant when co-administered with soluble antigens. However, its use in mucosal immunity is inconvenient because of its low yield and depolymerization during long-term storage under normal condition. In this study, we report an efficient expression system and optimized purification and storage strategy of LT. A gene encoding LT was cloned into the vector pET11c and transformed in E. coli BL21(DE3). By growing this strain on modified M9-CAA medium, LT was expressed efficiently. About 46mg/L LT could be purified from the supernatant of bacteria lysate. Using D(+)-Immobilized galactose column, LT could be purified at a wide pH range with various elution buffers. The optimized elution buffers are TEAN (pH 7.3) containing 0.3mol/L galactose and carbonate buffer (pH 10.4) containing 0.3mol/L galactose. After dried by freeze and placed in 4 degrees C, LT dissolved in TEAN (pH 7.3) and carbonate buffer (pH 10.4) were assayed by HPLC. The results indicated that the integrity of AB5 hexamer was kept well. LT could undergo long-term storage under this condition. This was proved to be an optimized strategy of LT storage. The results of GM1 binding assay and toxicity assay showed that the purified recombinant LT has normal biological character. PMID:15969079

Feng, Qiang; Cai, Shao-Xi; Yang, Jun; Luo, Ping; Zhang, Wei-Jun; Zou, Quan-Ming

2003-09-01

141

Active heat exchange system development for latent heat thermal energy storage  

NASA Technical Reports Server (NTRS)

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

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

1980-01-01

142

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

143

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

144

MODELLING AND NUMERICAL SIMULATION OF HEAT AND MASS TRANSFER DURING VACUUM DRYING OF A POROUS MEDIUM  

Microsoft Academic Search

Heat and mass transfer at the frontier of a multiphase medium and its surroundings are only theoretically well described under boundary layer hypothesis. In the other cases, theoretical study of interfacial transfer is very difficult due to the geometry of the physical frontier between the material and its surroundings, or due to the process by itself : vacuum drying, high

A. Erriguible; P. Bernada; F. Couture; M. A. Roques

145

Modeling of Heat and Mass Transfer at the Boundary Between A Porous Medium and Its Surroundings  

Microsoft Academic Search

Heat and mass transfer at the frontier of a multiphase medium and its surroundings are only theoretically well described under boundary layer hypothesis. In the other cases, theoretical study of interfacial transfer is very difficult due to the geometry of the physical frontier between the material and its surroundings, or due to the process by itself: vacuum drying, high temperature

A. Erriguible; P. Bernada; F. Couture; M.-A. Roques

2005-01-01

146

The morphology of cavitation damage of heat-treated medium carbon steel  

Microsoft Academic Search

In this paper the morphology of the cavitation damage to heat-treated medium carbon steel was analyzed. The experiments were conducted using a modified vibratory cavitation test set up. The erosion rates were measured by an analytical method. The mor- phology of the cavitation damage was studied by the scanning electron microscopy and optical microscopy techniques. The present work was aimed

MARINA DOJ

147

Discontinuous finite element method for radiative heat transfer in semitransparent graded index medium  

NASA Astrophysics Data System (ADS)

To avoid the complicated and time-consuming computation of curved ray trajectories, a discontinuous finite element method based on discrete ordinate equation is extended to solve the radiative transfer problem in a multi-dimensional semitransparent graded index medium. Two cases of radiative heat transfer in two-dimensional rectangular gray semitransparent graded index medium enclosed by opaque boundary are examined to verify this discontinuous finite element method. Special layered and radial graded index distributions are considered. The predicted dimensionless net radiative heat fluxes and dimensionless temperature distributions are determined by the discontinuous finite element method and compared with the results obtained by the curved Monte Carlo method in references. The results show that the discontinuous finite element method has a good accuracy in solving the multi-dimensional radiative transfer problem in a semitransparent graded index medium.

Liu, L. H.; Liu, L. J.

2007-07-01

148

Seasonal storage solar heating system for the Charlestown, Boston Navy Yard National Historic Park  

SciTech Connect

This paper concerns the design and analysis of a solar energy system using seasonal heat storage for the National Historic Park in the Charlestown Navy Yard, Boston, Massachusetts. The system uses two existing underground concrete storage tanks filled with water as the heat store and makes use of an existing tunnel network for placement of the heat distribution pipe network. The system includes a heat pump and is designed to supply about 1000 MWH of solar heat to displace the hot water and space heat demand. The study is part of the US participation in the International Energy Agency Solar Heating ad Cooling Program, Task VII on Central Solar Heating Plants using Seasonal Storage. System analysis was performed using the MINSUN computer simulation model developed by this Task specifically for solar seasonal storage systems with district heating. Analytic results indicated a substantial performance improvement by incorporating a heat pump into the system to extend the useful storage temperature range and reduce the annual average system temperatures.

Breger, D.S.; Michaels, A.I.

1984-04-30

149

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

Microsoft Academic Search

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

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

2000-01-01

150

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

Microsoft Academic Search

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

R. Yumruta?; M. Ünsal

2000-01-01

151

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

Microsoft Academic Search

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

Meckler

1988-01-01

152

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

E-print Network

unit of the phase change heat transfer model. It was solved numerically by an enthalpy-based finite difference method and was validated by experimental data. CaCl2•6H2O was used as the PCM in the latent heat storage system of SAGSHP system. In the tank...

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

2006-01-01

153

Nonsimilar hydromagnetic simultaneous heat and mass transfer by mixed convection from a vertical plate embedded in a uniform porous medium  

SciTech Connect

Simultaneous heat and mass transfer from different geometries embedded in porous media has many engineering and geophysical applications, such as migration of water in geothermal reservoirs, underground spreading of chemical wastes and other pollutants, thermal insulation, enhanced oil recovery, packed-bed catalytic reactors, cooling of nuclear reactors, grain storage, and evaporative cooling and solidification. This work considers steady, laminar, hydromagnetic simultaneous heat and mass transfer by mixed convection flow over a permeable vertical plate immersed in a uniform porous medium for the cases of power law variations of both the wall temperature and concentration and the wall heat flux and mass flux. Appropriate transformations are employed to transform the governing differential equations to a nonsimilar form. The transformed equations are solved numerically by an accurate, implicit, iterative, finite difference method. The obtained results are validated by favorable comparisons with previously published work on special cases of the problem. A parametric study illustrating the influence of all involved parameters on the local Nusselt and Sherwood numbers is conducted. The results of this parametric study are shown graphically, and the physical aspects of the problem are discussed.

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

1999-08-27

154

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

SciTech Connect

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

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

2009-11-15

155

Active heat exchange system development for latent heat thermal energy storage  

NASA Technical Reports Server (NTRS)

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

Alario, J.; Haslett, R.

1980-01-01

156

Experimental Analysis of Thermal Stratification in a Heat Storage Tank Using Stratification Pipe  

NASA Astrophysics Data System (ADS)

The heat storage tank is an important element in any heating system where the heat source is not able to provide heat accordingly to consumer demand (for example solar collector systems, solid fuel boilers etc). Better heat storage efficiency can be achieved by providing good thermal stratification in the heat storage tanks. One of the best methods of increasing the degree of thermal stratification is the stratification pipes. In the Environmental monitoring laboratory of the Institute of Energy Systems and Environment (Riga Technical University, an experimental heat storage system has been developed and used for testing and studying stratification devices under different thermodynamic and hydraulic conditions. The experimental study carried out on the efficiency of the stratification pipe produced by German company SOLVIS Solar Systeme GmbH under different flow parameters, has been analyzed. The main aim of the experimental study was to define optimal heating system operation parameters to achieve good performance of the stratification pipe and a high degree of thermal stratification in the heat storage tank.

Bolo?ina, A.; Rochas, C.; Blumberga, D.

2009-01-01

157

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. PMID:23391481

2013-01-01

158

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

E-print Network

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

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

1982-01-01

159

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

E-print Network

ICEBO2006, Shenzhen, China Renewable Energy Resources and a Greener Future Vol.VIII-1-4 Study of Applications of Solar Heating Systems with Seasonal Storage in China Guoqing Yu Xin Zhao Peng Chen Associate...

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

2006-01-01

160

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

161

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

SciTech Connect

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., E-mail: mohammad.mirmoosa@aalto.fi; Nefedov, I. S., E-mail: igor.nefedov@aalto.fi; Simovski, C. R., E-mail: konstantin.simovski@aalto.fi [Department of Radio Science and Engineering, School of Electrical Engineering, Aalto University, P. O. Box 13000, 00076 Aalto (Finland); Rüting, F., E-mail: felix.ruting@uam.es [Departamento de Física Teorica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autonoma de Madrid, E-28049 (Spain)

2014-06-21

162

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

163

Delayed effect of heat stress on steroid production in medium-sized and preovulatory bovine follicles.  

PubMed

During the autumn, the conception rate of dairy cattle in warm countries is low although ambient temperatures have decreased and cows are no longer exposed to summer thermal stress, indicating that there may be a delayed effect of heat stress on cattle fertility. Two experiments were conducted to examine possible delayed effects of heat stress on follicular characteristics and steroid production at two distinct stages of follicular growth: medium-sized and preovulatory follicles, 20 and 26 days after heat exposure, respectively. Lactating cows were subjected to heat stress for 12 h a day in an environmental chamber, during days 2-6 of a synchronized oestrous cycle. In Expt 1, ovaries were collected on day 3 of the subsequent cycle, before selection of the dominant follicle, and medium-sized follicles were classified as atretic or healthy. In Expt 2, on day 7 of the subsequent cycle, PGF(2a) was administered and preovulatory follicles were collected 40 h later. In both experiments, follicular fluid was aspirated, granulosa and thecal cells were incubated, and steroid production was determined. In healthy medium-sized follicles (Expt 1), oestradiol production by granulosa cells and androstenedione production by thecal cells were lower (P < 0.05) and the concentration of progesterone in the follicular fluid was higher in cows that had been previously heat-stressed than in control cows (P < 0.05). In preovulatory follicles (Expt 2), the viability of granulosa cells was lower (P < 0.05) and the concentration of androstenedione in the follicular fluid and its production by thecal cells were lower (P < 0.05) in cows that had been previously heat-stressed than in control cows. In both experiments, the oestradiol concentrations in the follicular fluids were not altered by heat stress. These results demonstrate a delayed effect of heat stress on steroid production and follicular characteristics in both medium-sized and preovulatory follicles; this effect could be related to the low fertility of cattle in the autumn. PMID:11427162

Roth, Z; Meidan, R; Shaham-Albalancy, A; Braw-Tal, R; Wolfenson, D

2001-05-01

164

Least-squares finite element method for radiation heat transfer in graded index medium  

NASA Astrophysics Data System (ADS)

To avoid the complicated and time-consuming computation of curved ray trajectories, a least-squares finite element method based on discrete ordinate equation is extended to solve the radiative transfer problem in a multi-dimensional semitransparent graded index medium. Four cases of radiative heat transfer are examined to verify this least-squares finite element method. Linear and nonlinear graded index are considered. The predicted dimensionless net radiative heat fluxes are determined by the least-squares finite element method and compared with the results obtained by other methods. The results show that the least-squares finite element method is stable and has a good accuracy in solving the multi-dimensional radiative transfer problem in a semitransparent graded index medium, while the Galerkin finite element method sometimes suffers from nonphysical oscillations.

Liu, L. H.

2007-02-01

165

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

166

Finite element method for radiation heat transfer in multi-dimensional graded index medium  

NASA Astrophysics Data System (ADS)

In graded index medium, ray goes along a curved path determined by Fermat principle, and curved ray-tracing is very difficult and complex. To avoid the complicated and time-consuming computation of curved ray trajectories, a finite element method based on discrete ordinate equation is developed to solve the radiative transfer problem in a multi-dimensional semitransparent graded index medium. Two particular test problems of radiative transfer are taken as examples to verify this finite element method. The predicted dimensionless net radiative heat fluxes are determined by the proposed method and compared with the results obtained by finite volume method. The results show that the finite element method presented in this paper has a good accuracy in solving the multi-dimensional radiative transfer problem in semitransparent graded index medium.

Liu, L. H.; Zhang, L.; Tan, H. P.

2006-02-01

167

Least-squares finite element method for radiation heat transfer in graded index medium  

Microsoft Academic Search

To avoid the complicated and time-consuming computation of curved ray trajectories, a least-squares finite element method based on discrete ordinate equation is extended to solve the radiative transfer problem in a multi-dimensional semitransparent graded index medium. Four cases of radiative heat transfer are examined to verify this least-squares finite element method. Linear and nonlinear graded index are considered. The predicted

L. H. Liu

2007-01-01

168

Storage of sun's heat by using modified carbon nanotubes  

Microsoft Academic Search

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

Balasai Sabarinath; Pradeep Elangovan

2011-01-01

169

Energy-Storage Modules for Active Solar Heating and Cooling  

NASA Technical Reports Server (NTRS)

34 page report describes a melting salt hydrate that stores 12 times as much heat as rocks and other heavy materials. Energy is stored mostly as latent heat; that is, heat that can be stored and recovered without any significant change in temperature. Report also describes development, evaluation and testing of permanently sealed modules containing salt hydrate mixture.

Parker, J. C.

1982-01-01

170

Assessment of solar heating systems with seasonal storage in New England: systems using duct storage in rock and a heat pump  

SciTech Connect

This report assesses seasonal storage of solar energy for the New England region, using duct storage in rock and a heat pump. The winter climate in New England requires large heating loads, and the winter insolation is inadequate for significant solar contributions from diurnal or passive systems. The abundant solar energy available during the remainder of the year could be of great value if coupled with a seasonal storage facility. Analyses are performed for flat plate and unglazed collectors, for low- and high-temperature load demands, and for various locations in New England. A heat pump is used in the system to reduce the storage temperature, thereby increasing collector efficiency and reducing losses. The results of the analysis indicate that in the optimized systems solar energy could provide 75 to 80% of the low-temperature demand load and 60 to 65% of high-temperature demand load, with the remaining portion coming primarily from the heat pump's electrical-energy input. The annual cost of the energy supplied by the system to the distribution network (using the base-case economic scenario) is $44 to 52/MWh and $58 to 62/MWh for the low- and high-temperature loads, respectively. Significant reductions in cost are attained when systems are financed using present incentives provided by the federal government.

Breger, D.S.; Michaels, A.I.

1985-01-01

171

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

E-print Network

with the sterilisation value reached in the course of the previous23 heat treatment. A sharp effect of the p Stone, 1952).37 The heat resistance of Bacillus cereus spores is extremely variable, with a D-valueQUANTIFYING THE COMBINED EFFECTS OF THE HEATING TIME,1 THE TEMPERATURE AND THE RECOVERY MEDIUM PH

Paris-Sud XI, Université de

172

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

Microsoft Academic Search

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

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

2007-01-01

173

Importance of Salinity Measurements in the Heat Storage Estimation from Topex/Poseidon  

NASA Technical Reports Server (NTRS)

Sea surface height anomaly signals from satellite altimeter data are used to estimate heat storage. Since variability in sea surface height is mostly due to expansion and contraction of the water column it can be correlated with variations in the heat and salt content.

Sato, O.; Polito, P.; Liu, W.

1999-01-01

174

Heat storage of pavement and its effect on the lower atmosphere  

Microsoft Academic Search

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

Akio Wake

1996-01-01

175

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

176

Simulation and optimisation of gas storage tanks filled with heat sink  

Microsoft Academic Search

One of the unique features of the pebble bed modular reactor (PBMR) is its load following capability, enabled by extracting or injecting of helium from or to the system during operation.Filling the tanks with a heat sink would reduce the necessary gas storage area dramatically. The heat sink would absorb the energy that the hot gas contains and consequently the

W. J. van Rooyen; D. L. W. Krueger; E. H. Mathews; M. Kleingeld

2006-01-01

177

Method and system for the compact storage of heat and coolness by phase change materials  

Microsoft Academic Search

While many materials and additives which will melt and freeze at various temperature levels for storing and releasing large amounts of heat thereby per unit volume have been disclosed, the packaging of these materials with suitable non-corrodible longlasting heat exchange structures has been cumbersome and expensive. The present invention provides an inexpensive, high performance, non-corrodible thermal storage method and system

Maccracken

1981-01-01

178

Parametric analysis of cyclic phase change and energy storage in solar heat receivers  

Microsoft Academic Search

A parametric study on cyclic melting and freezing of an encapsulated phase change material (PCM), integrated into a solar heat receiver, has been performed. The cyclic nature of the present melt\\/freeze problem is relevant to latent heat thermal energy storage (LHTES) systems used to power solar Brayton engines in microgravity environments. Specifically, a physical and numerical model of the solar

Emmanuel K. Glakpe; Joseph N. Cannon; Thomas W. Kerslake

1997-01-01

179

Utilization of Latent Heat Storage Unit for Comfort Ventilation of Buildings in Hot and Dry Climates  

Microsoft Academic Search

In hot and dry climatic conditions of South Asia, summer night temperatures are low, and phase change material (PCM) based heat storage technique could be used as heat sink to reduce ambient air temperature during hot day times, as an alternate of current ventilation techniques for the building sector. This can help in reducing electricity consumption and consequently reducing green

A. Waqas; S. Kumar

2011-01-01

180

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

E-print Network

National Oceanic and Atmospheric Administration, Great Lakes Environmental Research Laboratory Ann Arbor the Great Lakes have a tremendous heat storage capacity, a very important factor in the heat budget studies budget as one of several methods to compute lake evaporation. The period of record for the energy budget

181

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

Microsoft Academic Search

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

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

1996-01-01

182

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.

183

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

Microsoft Academic Search

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

J. Jänchen; D. Ackermann; H. Stach; W. Brösicke

2004-01-01

184

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

185

Heat extraction for the CSPonD thermal storage unit  

E-print Network

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

Rojas, Folkers Eduardo

2011-01-01

186

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

187

Short-term in vitro storage of t Miscanthus x ogiformis Honda 'Giganteus' as affected by medium composition, temperature, and photon flux density  

Microsoft Academic Search

Miscanthus x ogiformis Honda 'Giganteus' shoot cultures were stored in vitro on proliferation or rooting medium for up to 27 weeks at temperatures\\u000a of 8, 12, 16, or 20 C and photosynthetic photon flux densities of 5, 10, or 20 mol m?2 s?1. Plants survived storage much better on rooting medium than on proliferation medium. Plants stored on rooting medium

Jürgen Hansen; Kell Kristiansen

1997-01-01

188

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. PMID:24069532

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

2013-01-01

189

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

190

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

191

SERODS: a new medium for high-density optical data storage  

NASA Astrophysics Data System (ADS)

A new optical dada storage technology based on the surface- enhanced Raman scattering (SERS) effect has been developed for high-density optical memory and three-dimensional data storage. With the surface-enhanced Raman optical data storage (SERODS) technology, the molecular interactions between the optical layer molecules and the nanostructured metal substrate are modified by the writing laser, changing their SERS properties to encode information as bits. Since the SERS properties are extremely sensitive to molecular nano- environments, very small 'spectrochemical holes' approaching the diffraction limit can be produced for the writing process. The SERODS device uses a reading laser to induce the SERS emission of molecules on the disk and a photometric detector tuned to the frequency of the RAMAN spectrum to retrieve the stored information. The results illustrate that SERODS is capable of three-dimensional data storage and has the potential to achieve higher storage density than currently available optical data storage systems.

Vo-Dinh, Tuan; Stokes, David L.

1998-10-01

192

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

NASA Astrophysics Data System (ADS)

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

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

2011-02-01

193

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

NASA Astrophysics Data System (ADS)

We consider the problem of self-regulated heating and cooling in galaxy clusters and the implications for cluster magnetic fields and turbulence. Viscous heating of a weakly collisional magnetized plasma is regulated by the pressure anisotropy with respect to the local direction of the magnetic field. The intracluster medium is a high-beta plasma, where pressure anisotropies caused by the turbulent stresses and the consequent local changes in the magnetic field will trigger very fast microscale instabilities. We argue that the net effect of these instabilities will be to pin the pressure anisotropies at a marginal level, controlled by the plasma beta parameter. This gives rise to local heating rates that turn out to be comparable to the radiative cooling rates. Furthermore, we show that a balance between this heating and Bremsstrahlung cooling is thermally stable. Given a sufficient (and probably self- regulating) supply of turbulent power, this provides a physical mechanism for mitigating cooling flows and preventing cluster core collapse. A balance between parallel viscous heating and radiative cooling gives predictions for magnetic field strengths, turbulent velocities and turbulent scales. If confirmed, these predictions would constitute strong evidence that microphysical processes play an important role in the large-scale structure and evolution of galaxy clusters.

Kunz, Matthew; Schekochihin, Alexander

2010-11-01

194

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

195

Optimal design of ground source heat pump system integrated with phase change cooling storage tank in an office building  

E-print Network

source heat pump; phase change cooling storage: optimal design; storage ratio 1 Introduction Geothermal energy is increasingly used through the ground source heat pump (GSHP) in many countries. GSHP provides an efficient and environment friendly way... design of the combined system, are listed below: (a) Wuhan is a cooling-dominated area with abundant geothermal energy. Ground source heat pump technology could use renewable energy and the phase change cooling storage technology could shifted peak...

Zhu, N.

2014-01-01

196

Solar district-heating system using seasonal storage for the Charlestown, Boston Navy Yard redevelopment project  

NASA Astrophysics Data System (ADS)

A preliminary analysis is presented for a seasonal storage solar heating system for the Charlestown Navy Yard in Boston, Massachusetts. The system makes use of two large, buried concrete storage tanks totalling 5700 m(3) as a water heat store. The analysis makes extensive use of MINSUN, a computer performance and economic simulation routine written specifically for solar seasonal storage systems. The system performance and economics are analyzed for different collector types and areas, component costs, exogenous economic conditions, and optional inclusion of a heat pump. System cost-effectiveness is defined in relation to an economic break-even situation with respect to a conventional system, and is presented in terms of a solar premium, which is the incremented cost for the solar system per megawatt hour (MWH) of conventional fuel displaced. Results indicate a solar premium of about $15 per MWH for parabolic collectors and $10 MWH for advanced evacuated tubes given estimated 1985 collector costs.

Breger, D.

1982-09-01

197

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

198

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

NASA Technical Reports Server (NTRS)

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

Misra, Ajay K.

1988-01-01

199

Experimental Study on Crawl-Space Heating with Thermal Storage using Heat Pump  

Microsoft Academic Search

SUMMARY : In the house that has a crawl space with the insulated foundation walls and non-insulated floor over the crawl space, if all the crawl space can be heated, then the entire floor will be heated, and as the result whole the space of the first floor will become the radiant heating environment. We call this heating system 'Crawl-space

Takayuki Matsushita

200

Do encapsulated heat storage materials really retain their original thermal properties?  

PubMed

The encapsulation of Rubitherm®27 (RT27), which is one of the most common commercially supplied heat storage materials, by polystyrene (PS), polydivinyl benzene (PDVB) and polymethyl methacrylate (PMMA) was carried out using conventional radical microsuspension polymerization. The products were purified to remove free RT27 and free polymer particles without RT27. In the cases of PS and PDVB microcapsules, the latent heats of melting and crystallization for RT27 ( and , J/g-RT27) were clearly decreased by the encapsulation. On the other hand, those of the PMMA microcapsules were the same as pure RT27. A supercooling phenomenon was observed not only for PS and PDVB but also for the PMMA microcapsules. These results indicate that the thermal properties of the heat storage materials encapsulated depend on the type of polymer shells, i.e., encapsulation by polymer shell changes the thermal properties of RT27. This is quite different from the idea of other groups in the world, in which they discussed the thermal properties based on the ?Hm and ?Hc values expressed in J/g-capsule, assuming that the thermal properties of the heat storage materials are not changed by the encapsulation. Hereafter, this report should raise an alarm concerning the "wrong" common knowledge behind developing the encapsulation technology of heat storage materials. PMID:25412246

Chaiyasat, Preeyaporn; Noppalit, Sayrung; Okubo, Masayoshi; Chaiyasat, Amorn

2014-12-10

201

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

202

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

E-print Network

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

Barineau, Mark Michael

2010-01-01

203

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

Microsoft Academic Search

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

M Lacroix

1993-01-01

204

Compact storage of heat and coolness by phase change materials while preventing stratification  

Microsoft Academic Search

While many materials and additives which will melt and freeze at various temperature levels for storing and releasing large amounts of heat thereby per unit volume have been disclosed, the packaging of these materials with suitable non-corrodible long-lasting heat exchange structures has been cumbersome and expensive. The present invention provides an inexpensive, high performance, non-corrodible thermal storage method and system

MacCracken

1983-01-01

205

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

206

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

207

Impact of changes in composition of storage medium on lipid content and quality of turkey spermatozoa.  

PubMed

Turkey semen quality is damaged by long term in vitro storage. The objective of the present study was to determine whether changes in energy substrates and antioxidants of semen extender could limit loss of quality and lipid content of turkey spermatozoa during storage. Spermatozoa were incubated in extenders based on Beltsville Poultry Semen Extender (BPSE) to which different energy substrates (acetate, pyruvate and hydroxybutyric acid) or antioxidant (Vitamin E) had been added. Semen was stored at 4 degrees C for 48 h and changes in quality, phospholipid and malondialdehyde (MDA) content of semen were evaluated. Among the different substrates studied, only acetate was able to limit the loss of motility and ATP content after 48 h in vitro storage. Losses of spermatozoal phospholipids were similar when gametes were incubated in an extender without any substrate or in normal BPSE (784-675nmol/10(9) spz versus 837-703 nmol/10(9) spz). However, motility and ATP content were significantly more affected after 48 h of storage in samples incubated without substrates than in BPSE (motility, 2.2 versus 0; ATP, 10 nmol/10(9) spz versus 3 nmol/10(9) spz). The addition of Vitamin E to the extender did not modify either the MDA or phospholipid content of fresh or stored spermatozoa, but increased the motility of stored semen. In conclusion, acetate is an essential substrate for in vitro storage. Spermatozoal phospholipids decreased during storage, but this did not seem to originate from metabolism of endogenous fatty acids. The positive effects of Vitamin E on semen storage did not originate from preservation of lipid oxidation. PMID:14643857

Douard, V; Hermier, D; Magistrini, M; Labbé, C; Blesbois, E

2004-01-01

208

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

209

Thermal energy storage for low grade heat in the organic Rankine cycle  

NASA Astrophysics Data System (ADS)

Limits of efficiencies cause immense amounts of thermal energy in the form of waste heat to be vented to the atmosphere. Up to 60% of unrecovered waste heat is classified as low or ultra-low quality, making recovery difficult or inefficient. The organic Rankine cycle can be used to generate mechanical power and electricity from these low temperatures where other thermal cycles are impractical. A variety of organic working fluids are available to optimize the ORC for any target temperature range. San Diego State University has one such experimental ORC using R245fa, and has been experimenting with multiple expanders. One limitation of recovering waste heat is the sporadic or cyclical nature common to its production. This inconsistency makes sizing heat recovery ORC systems difficult for a variety of reasons including off-design-point efficiency loss, increased attrition from varying loads, unreliable outputs, and overall system costs. Thermal energy storage systems can address all of these issues by smoothing the thermal input to a constant and reliable level and providing back-up capacity for times when the thermal input is deactivated. Multiple types of thermal energy storage have been explored including sensible, latent, and thermochemical. Latent heat storage involves storing thermal energy in the reversible phase change of a phase change material, or PCM, and can have several advantages over other modalities including energy storage density, cost, simplicity, reliability, relatively constant temperature output, and temperature customizability. The largest obstacles to using latent heat storage include heat transfer rates, thermal cycling stability, and potentially corrosive PCMs. Targeting 86°C, the operating temperature of SDSU's experimental ORC, multiple potential materials were explored and tested as potential PCMs including Magnesium Chloride Hexahydrate (MgCl2?6H2O), Magnesium Nitrate Hexahydrate (Mg(NO3)2?6H 2O), montan wax, and carnauba wax. The addition of graphite to augment heat transfer rates was also tested. Melting and solidification temperatures largely matched predictions. The magnesium salts were found to be less stable under thermal cycling than the waxes. Graphite was only soluble in the waxes. Mixtures of magnesium salts and waxes yielded a layered composite with the less dense waxes creating a sealing layer over the salt layer that significantly increased the stability of the magnesium salts. Research into optimum heat exchangers and storage vessels for these applications indicates that horizontally oriented aluminum pipes with vertically oriented aluminum fins would be the best method of storing and retrieving energy. Fin spacing can be predicted by an equation based on target temperatures and PCM characteristics.

Soda, Michael John

210

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

NASA Technical Reports Server (NTRS)

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

Bootle, John

2008-01-01

211

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

Microsoft Academic Search

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

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

1992-01-01

212

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

Microsoft Academic Search

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

Santosh K. Mukka; Muhammad M. Rahman

2004-01-01

213

Ethanol Production and Chlorophyll Fluorescence Indicate Freezing and Heat Stress in Apple Fruit During Storage  

Microsoft Academic Search

IntroductionThe quality and storage life of fresh fruit and vegetable are affectedby different pre- and post harvest factors. Stresses such as nutrientdeficiencies, freezing, heat, low oxygen, high concentration of carbondioxide, or drought cause physiological damage resulting in reducedstorage life and quality (Lurie and Klein, 1990, Forney and Jordan,1998, Volz et al., 1998). Determining physiological changes in fruitand predicting their potential

C. F. Forney; J. Song; L. H. Fan; M. A. Jordan

214

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

Microsoft Academic Search

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

Nishita

1980-01-01

215

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

E-print Network

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

Tackett, R. K.

1989-01-01

216

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

Microsoft Academic Search

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

D. S. Breger; A. I. Michaels

1983-01-01

217

Once-through heat transport and seasonal storage for city of Bellingham  

NASA Astrophysics Data System (ADS)

A conceptual design of a once-through district heating system utilizing industrial waste heat was developed for the city of Bellingham, Washington. Two once-through designs are evaluated. Case 1 is based on an assumption that 67 MWt can be obtained from an aluminum plant and supplementary heat sources and does not require a seasonal thermal storage facility. Case 2 is based on the extraction of 45 MWt from the aluminum plant and requires a seasonal thermal storage facility. These once-through systems were compared with the closed district heating system design which uses a two-pipe heat transport arrangement that returns the used water to the aluminum plant. In 1980 dollars, once through system case 1 would provide an economic advantage of about $10.7 million over the closed system. Case 2 would incur a disadvantage of about $9.1 million in comparison with the closed system, largely because of the high cost of seasonal thermal storage tanks.

Oliker, I.; Olszewski, M.

1981-10-01

218

[The design of heat dissipation of the field low temperature box for storage and transportation].  

PubMed

Because of the compact structure of the field low temperature box for storage and transportation, which is due to the same small space where the compressor, the condenser, the control circuit, the battery and the power supply device are all placed in, the design for heat dissipation and ventilation is of critical importance for the stability and reliability of the box. Several design schemes of the heat dissipation design of the box were simulated using the FLOEFD hot fluid analysis software in this study. Different distributions of the temperature field in every design scheme were constructed intimately in the present study. It is well concluded that according to the result of the simulation analysis, the optimal heat dissipation design is decent for the field low temperature box for storage and transportation, and the box can operate smoothly for a long time using the results of the design. PMID:23488142

Wei, Jiancang; Suin, Jianjun; Wu, Jian

2013-02-01

219

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

NASA Technical Reports Server (NTRS)

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

Christy, John R.

1991-01-01

220

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

Microsoft Academic Search

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

Zhongping Chen; Hiroyuki Takei; Aaron Lewis; Isaiah Nebenzahl

1991-01-01

221

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

Technology Transfer Automated Retrieval System (TEKTRAN)

The US collection of mountain mint (Pycnanthemum Michx.) is held at the USDA-ARS National Clonal Germplasm Repository (NCGR) in Corvallis, OR as seed, potted plants and tissue cultures and a long-term storage collection is preserved at the USDA-ARS National Center for Genetic Resources Preservation ...

222

Transient one-dimensional heat flow technique applied to porous reactive medium  

NASA Astrophysics Data System (ADS)

A transient one-dimensional heat flow technique was presented to measure the effective thermal conductivity of porous reactive media. The porous reactive medium was in contact with a flat thermistor in a cell, and vacuum was applied to remove the air and the moisture. Afterwards, ammonia atmosphere was maintained in the cell under a fixed temperature and pressure. A varistor with max. 100 ? was used to equate with the resistance of the thermistor corresponding to the fixed temperature. The temperature increase of thermistor was 2-3 °C, which was sufficient to avoid the enthalpy effect due to chemical reaction. A graphite-CaCl2?nNH3 complex was given as a test specimen for the porous reactive medium. Measurements showed that the thermal conductivity of graphite-CaCl2?8NH3 complex has distinctively higher values than the graphite-CaCl2?4NH3 and CaCl2?2NH3 complex. The accuracy of measured conductivity was estimated to be within 10%.

Han, Jong Hun; Cho, Kil Won; Lee, Kun-Hong; Kim, Hwayong

1998-08-01

223

The seasonal cycle of diabatic heat storage in the Pacific Ocean  

USGS Publications Warehouse

This study quantifies uncertainties in closing the seasonal cycle of diabatic heat storage (DHS) over the Pacific Ocean from 20??S to 60??N through the synthesis of World Ocean Circulation Experiment (WOCE) reanalysis products from 1993 to 1999. These products are DHS from Scripps Institution of Oceanography (SIO); near-surface geostrophic and Ekman currents from Earth and Space Research (ESR); and air-sea heat fluxes from Comprehensive Ocean-Atmosphere Data Set (COADS), National Centers for Environmental Prediction (NCEP), and European Center for Mid-Range Weather Forecasts (ECMWF). With these products, we compute residual heat budget components by differencing long-term monthly means from the long-term annual mean. This allows the seasonal cycle of the DHS tendency to be modeled. Everywhere latent heat flux residuals dominate sensible heat flux residuals, shortwave heat flux residuals dominate longwave heat flux residuals, and residual Ekman heat advection dominates residual geostrophic heat advection, with residual dissipation significant only in the Kuroshio-Oyashio current extension. The root-mean-square (RMS) of the differences between observed and model residual DHS tendencies (averaged over 10??latitude-by-20??longitude boxes) is <20 W m-2 in the interior ocean and <100 W m-2 in the Kuroshio-Oyashio current extension. This reveals that the residual DHS tendency is driven everywhere by some mix of residual latent heat flux, shortwave heat flux, and Ekman heat advection. Suppressing bias errors in residual air-sea turbulent heat fluxes and Ekman heat advection through minimization of the RMS differences reduces the latter to <10 W m-2 over the interior ocean and <25 W m -2 in the Kuroshio-Oyashio current extension. This reveals air-sea temperature and specific humidity differences from in situ surface marine weather observations to be a principal source of bias error, overestimated over most of ocean but underestimated near the Intertropical Convergence Zone. ?? 2005 Elsevier Ltd. All rights reserved.

White, W.B.; Cayan, D.R.; Niiler, P.P.; Moisan, J.; Lagerloef, G.; Bonjean, F.; Legler, D.

2005-01-01

224

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

225

Radiotoxicity and decay heat power of spent nuclear fuel of VVER type reactors at long-term storage.  

PubMed

Radiotoxicity and decay heat power of the spent nuclear fuel of VVER-1000 type reactors are calculated during storage time up to 300,000 y. Decay heat power of radioactive waste (radwaste) determines parameters of the heat removal system for the safe storage of spent nuclear fuel. Radiotoxicity determines the radiological hazard of radwaste after its leakage and penetration into the environment. PMID:16381764

Bergelson, B R; Gerasimov, A S; Tikhomirov, G V

2005-01-01

226

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

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

227

The Vermont Biomass Gasifier Project -- Medium heating value gas for electric power applications  

SciTech Connect

The Vermont Biomass Gasifier Project is part of a major DOE initiative to demonstrate indirect gasification of renewable biomass for electricity production. The Vermont Project has been undertaken to demonstrate the integration of the Battelle Columbus Laboratories (Battelle) indirectly-heated gasifier with a high-efficiency gas turbine. The demonstration and validation of this gasification/gas turbine system is being performed at the existing 50 MW wood-fired McNeil Power Generating Station in Burlington, Vermont, thereby significantly reducing the time scale for deployment and the necessary capital investment for DOE and the Vermont project partnership. The development and commercialization of this technology is important for several reasons: (1) it does not require a hot-gas clean-up for gas turbine operation, thus removing this technical hurdle from the commercialization path; (2) it is the only US biomass gasification system that has successfully powered a gas turbine, supporting its near-term viability for commercial deployment; and (3) it produces a medium-heating-value gas without employing an oxygen plant, thus allowing the use of existing unmodified industrial gas turbines. Gasifier construction was completed in late 1997; commissioning and parametric testing was completed during the spring and summer of 1998. This paper discusses the results of this testing and presents plans for both the next phase of testing and prospects for near-term commercialization.

Craig, K.; Overend, R.P. [National Renewable Energy Lab., Golden, CO (United States); Gillette, L. [Dept. of Energy, Washington, DC (United States)

1998-12-31

228

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

229

Influence of Heat Treatment and Veneering on the Storage Modulus and Surface of Zirconia Ceramic  

PubMed Central

Objectives: Glass-ceramic veneered zirconia is used for the application as fixed partial dentures. The aim of this investigation was to evaluate whether the heat treatment during veneering, the application of glass-ceramic for veneering or long term storage has an influence on the storage modulus of zirconia. Methods: Zirconia bars (Cercon, DeguDent, G; 0.5x2x20 mm) were fabricated and treated according to veneering conditions. Besides heating regimes between 680°C and 1000°C (liner bake and annealing), sandblasting (Al2O3) or steam cleaning were used. The bars were investigated after 90 days storage in water and acid. For investigating the influence of veneering, the bars were veneered in press- or layer technique. Dynamic mechanical analysis (DMA) in a three-point-bending design was performed to determine the storage modulus between 25°C and 200°C at a frequency of 1.66 Hz. All specimens were loaded on top and bottom (treatment on pressure or tensile stress side). Scanning electron microscopy (SEM) was used for evaluating the superficial changes of the zirconia surface due to treatment. Statistical analysis was performed using Mann Whitney U-test (?=0.05). Results: Sintered zirconia provided a storage modulus E’ of 215 (203/219) GPa and tan ? of 0.04 at 110°C. A 10%-decrease of E’ was found up to 180°C. The superficial appearance changed due to heating regime. Sandblasting reduced E’ to 213 GPa, heating influenced E’ between 205 GPa (liner bake 1) and 222 GPa (dentin bake 1). Steam cleaning, annealing and storage changed E’ between 4 GPa and 22 GPa, depending on the side of loading. After veneering, strong E’-reduction was found down to 84 GPa and 125 GPa. Conclusions: Veneering of zirconia with glass-ceramic in contrast to heat treating during veneering procedure had a strong influence on the modulus. The application of the glass-ceramic caused a stronger decrease of the storage modulus. PMID:21494388

Siavikis, Georgius; Behr, Michael; van der Zel, Jef M; Feilzer, Albert J; Rosentritt, Martin

2011-01-01

230

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

231

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

232

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

NASA Astrophysics Data System (ADS)

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

Unal, H. C.

1981-03-01

233

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

SciTech Connect

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

Litzke, Wai-Lin

1992-12-01

234

Effects of Post Heat-Treatment on Surface Characteristics and Adhesive Bonding Performance of Medium Density Fiberboard  

Microsoft Academic Search

A series of commercially manufactured medium density fiberboard (MDF) panels were exposed to a post-manufacture heat-treatment at various temperatures and durations using a hot press and just enough pressure to ensure firm contact between the panel and the press platens. Post-manufacture heat-treatment improved surface roughness of the exterior MDF panels. Panels treated at 225°C for 30 min had the smoothest surface

Nadir Ayrilmis; Jerrold E. Winandy

2009-01-01

235

A Numerical Study of a Double Pipe Latent Heat Thermal Energy Storage System  

NASA Astrophysics Data System (ADS)

Solar energy is an intermittent supply source of energy. To efficiently utilize this free renewable energy source some form of thermal energy storage devices are necessary. Phase change materials (PCMs), because of their high energy density storage capacity and near isothermal phase change characteristics, have proven to be promising candidates for latent heat thermal energy storage (LHTES) devices. Among the various LHTES devices for low temperature residential heating and cooling applications, the shell-and-tube type heat exchanging devices are the most simple to operate and can be easily fabricated. This work numerically investigates the buoyancy driven heat transfer process during melting (charging) of a commercial paraffin wax as PCM filling the annulus of a horizontal double pipe heat exchanger. The heated working fluid (water) is passing through the central tube of the annulus at a sufficiently high flow-rate and thereby maintaining an almost isothermal wall temperature at the inner pipe which is higher than the melting temperature of the PCM. The transient, two-dimensional coupled laminar momentum and energy equations for the model are suitably non-dimensionalized and are solved numerically using the enthalpy-porosity approach. Time-wise evolutions of the flow patterns and temperature distributions are presented through velocity vector fields and isotherm plots. In this study, two types of PCM filled annuli, a plain annulus and a strategically placed longitudinal finned annulus, are studied. The total energy stored, the total liquid fraction and the energy efficiency at different melting times are evaluated for three different operating conditions and the results are compared between the plain and finned annuli. The present study will provide guidelines for system thermal performance and design optimization of the shell-and-tube LHTES devices. .

Tabassum, Tonny

236

Some thermophysical properties of paraffin wax as a thermal storage medium  

SciTech Connect

An experimental study is conducted to determine the suitability of paraffin wax SUNTECH P116 as a phase change material for storage of thermal energy. Certain temperature dependent thermophysical properties in the neighborhood of the melting point useful for this study, but not adequately available in the literature, are measured. They include thermal conductivity, density, thermal expansion coefficient, and viscosity. It is observed that the thermal conductivity of paraffin wax, in solid phase, is not a monotonic function of temperature as reported in the literature. Other thermophysical properties of the liquid phase measured vary monotonically with temperature.

Haji-Sheikh, A.; Eftekhar, J.; Lou, D.Y.S.

1982-01-01

237

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

238

Radiation Heat Transfer Modeling Improved for Phase-Change, Thermal Energy Storage Systems  

NASA Technical Reports Server (NTRS)

Spacecraft solar dynamic power systems typically use high-temperature phase-change materials to efficiently store thermal energy for heat engine operation in orbital eclipse periods. Lithium fluoride salts are particularly well suited for this application because of their high heat of fusion, long-term stability, and appropriate melting point. Considerable attention has been focused on the development of thermal energy storage (TES) canisters that employ either pure lithium fluoride (LiF), with a melting point of 1121 K, or eutectic composition lithium-fluoride/calcium-difluoride (LiF-20CaF2), with a 1040 K melting point, as the phase-change material. Primary goals of TES canister development include maximizing the phase-change material melt fraction, minimizing the canister mass per unit of energy storage, and maximizing the phase-change material thermal charge/discharge rates within the limits posed by the container structure.

Kerslake, Thomas W.; Jacqmin, David A.

1998-01-01

239

Solar district-heating system using seasonal storage for the Charlestown, Boston Navy Yard redevelopment project  

SciTech Connect

A preliminary analysis is presented for a seasonal storage solar heating system for the Charlestown Navy Yard in Boston, Massachusetts. The area occupies a prominent location in the Boston Harbor and is being receveloped for residential and commercial use. The system makes use of two large, buried concrete storage tanks totalling 5700 m/sup 3/ as a water heat store. Other storage facilities, including a dry dock, offer additional solar opportunities for the navy Yard as the redevelopment progresses. The analysis makes extensive use of MINSUN, a computer performance and economic simulation routine written specifically for solar seasonal storage systems. The system performance and economics are analyzed for different collector types and areas, component costs, exogenous economic conditions, and optional inclusion of a heat pump. System cost-effectiveness is defined in relation to an economic break-even situation with respect to a conventional system, and is presented in terms of a solar premium, which is the incremental cost for the solar system per MWH of conventional fuel displaced. Results indicate a solar premium of about $15/MWH for parabolic collectors and $10/MWH for advanced CPC evacuated tubes given estimated 1985 collector costs. Cost-effective solutions are found for these two and for flat plate collectors assuming projected collector costs for year 2000. Optimally sized systems for this case exhibit a solar fraction around 0.50 for the 2200 MWH annual heat load; at this point the system is volume constrained. The sensitivity of these results with respect to system parameters and economic assumptions is presented. The additional analysis and design considerations necessary before an implementation phase are outlined. System implementation is discussed in terms of the roles of the various parties involved and funding/financing possibilities.

Breger, D.

1982-09-01

240

The Effect of Porous Medium Storage on Unstable Density-Driven Solute Transport.  

PubMed

Unstable density-driven groundwater flow and solute transport (i.e., free convection) leads to spatiotemporal variations in pressure. Specific storage (So ) indicates the capability of a confined aquifer to release or store groundwater associated with a pressure change. Although So is known to dampen pressure propagation, So has been implicitly assumed to have a negligible impact on the unstable free convective process in prior studies. This work explores the effect of So on both the classic onset criterion and the fingering process using numerical models. Results show that the classic onset criterion is applicable when So is smaller than 10(-1) ?m(-1) . Results also demonstrate that So does not play a significant role in the free convective fingering process unless it is greater than 10(-3) ?m(-1) . For most practical purposes in hydrogeology (large Rayleigh number and small So ), the implicit assumption of small or zero So is appropriate. PMID:25393965

Xie, Yueqing; Graf, Thomas; Simmons, Craig T; Diersch, Hans-Jörg G

2014-11-13

241

Yttrium-dispersed C{sub 60} fullerenes as high-capacity hydrogen storage medium  

SciTech Connect

Interaction between hydrogen molecules and functionalized C{sub 60} is investigated using density functional theory method. Unlike transition metal atoms that tend to cluster on the surface, C{sub 60} decorated with 12 Yttrium atoms on each of its 12 pentagons is extremely stable and remarkably enhances the hydrogen adsorption capacity. Four H{sub 2} molecules can be chemisorbed on a single Y atom through well-known Dewar-Chatt-Duncanson interaction. The nature of bonding is a weak physisorption for the fifth adsorbed H{sub 2} molecule. Consequently, the C{sub 60}Y{sub 12} complex with 60 hydrogen molecules has been demonstrated to lead to a hydrogen storage capacity of ?6.30 wt. %.

Tian, Zi-Ya; Dong, Shun-Le, E-mail: dongshunle2013@hotmail.com [Department of Physics, Ocean University of China, Qingdao 266100 (China)] [Department of Physics, Ocean University of China, Qingdao 266100 (China)

2014-02-28

242

Heat storage and electricity generation in the Moon during the lunar night  

NASA Astrophysics Data System (ADS)

One of the biggest challenges of the exploration of the Moon is the survival of the crew and the lunar assets during the lunar night. The environmental conditions on the lunar surface and its cycle, with long periods of darkness, make any long mission in need of specific amounts of heat and electricity to be successful. We have analyzed two different systems to produce heat and electricity on the Moon's surface. The first system consists of Thermal Wadis, sources of thermal power that can be used to supply heat to protect the exploration systems from the extreme cold during periods of darkness. Previous results showed that Wadis can supply enough heat to keep lunar devices such as rovers above their minimum operating temperature (approximately 243 K). The second system studied here is the Thermal Energy Storage (TES), which is able to run a heat engine during the lunar night to produce electricity. When the Sun is shining on the Moon's surface, the system can run the engine directly using the solar power and simultaneously heat a thermal mass. This thermal mass is used as a high temperature source to run the heat engine during the night. We present analytical and numerical calculations for the determination of an appropriate thermal mass for the TES system.

Climent, Blai; Torroba, Oscar; González-Cinca, Ricard; Ramachandran, Narayanan; Griffin, Michael D.

2014-01-01

243

Numerical Simulation of Thermal Energy Storage in Underground Soil Heat Accumulator  

NASA Astrophysics Data System (ADS)

The alternative energy sources have been getting popular for last decades as a new way to obtain enough energy especially for countries which do not have rich natural reservoirs of fossil fuels. Gathering the thermal energy from the solar radiation seems to be as one of the cheapest alternatives of them. The disadvantage of it is the overflow of the heat energy during the summer and lack of them during the winter, when the demand for heat is on top. The underground thermal energy storage can be a good alternative for accumulating the heat energy and then offers it on demand. However, it is difficult to monitor the real physical condition in the soil. In the article, the results of numerical simulation are shown as a good way for a better identification of the process of accumulating the energy to the soil material.

Kortiš, Ján; Gottwald, Michal

2014-12-01

244

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

NASA Astrophysics Data System (ADS)

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 to a system of non-linear ordinary differential equations by using similarity transformations. Because of non-linearity, the governing equations are solved numerically. The effects of magnetic field on velocity and temperature distributions are studied in detail by considering uniform permeability (UP) and variable permeability (VP) of the porous medium and the results are discussed graphically. Besides, skin friction and Nusselt number are also computed for various physical parameters governing the problem under consideration. It is found that the inertial parameter has a significant influence in increasing the flow field and the rate of heat transfer for variable permeability case. The important finding of the present work is that the magnetic field has considerable effects on the boundary layer velocity and on the rate of heat transfer for variable permeability of the porous medium. Further, the results obtained under the limiting conditions were found to be in good agreement with the existing ones.

Pal, Dulal

2010-12-01

245

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

246

Effect of the medium characteristics and the heating and cooling rates on the nonisothermal heat resistance of Bacillus sporothermodurans IC4 spores.  

PubMed

In recent years, highly thermo-resistant mesophilic spore-forming bacteria belonging to the species Bacillus sporothermodurans have caused non-sterility problems in industrial sterilization processes. The aim of this research was to evaluate the effect of the heating medium characteristics (pH and buffer/food) on the thermal inactivation of B. sporothermodurans spores when exposed to isothermal and non-isothermal heating and cooling treatments and the suitability of non-linear Weibull and Geeraaerd models to predict the survivors of these thermal treatments. Thermal treatments were carried out in pH 3, 5 and 7 McIlvaine buffer and in a courgette soup. Isothermal survival curves showed shoulders that were accurately characterized by means of both models. A clear effect of the pH of the heating medium was observed, decreasing the D120 value from pH 7 to pH 3 buffer down to one third. Differences in heat resistance were similar, regardless of the model used and were kept at all temperatures tested. The heat resistance in courgette soup was similar to that shown in pH 7 buffer. When the heat resistance values obtained under isothermal conditions were used to predict the survival in the non-isothermical experiments, the predictions estimated the experimental data quite accurately, both with Weibull and Geeraerd models. PMID:23498193

Esteban, María-Dolores; Huertas, Juan-Pablo; Fernández, Pablo S; Palop, Alfredo

2013-05-01

247

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

SciTech Connect

This Phase II study provides further analysis for a seasonal-storage solar-heating system utilizing two existing underground, concrete tanks in the National Historic Park of the Charlestown Navy Yard in Boston. The initial Phase I study was reported in ANL-82-90. The new results focus on the effect of including a heat pump in the system to extend the useful heat-storage capacity of the tanks. The analysis was performed with MINSUN Version III, a computer simulation model written particularly for seasonal storage systems. Input parameters were derived in Phase I and reviewed and updated for this study. Three collector types were studied with and without a heat pump. Results indicate a definite performance and economic improvement for all collector types by including the heat pump. Flat plate collectors showed substantially greater improvement due to their more pronounced increase in efficiency at the lower inlet temperatures. With the heat pump, all three collectors provide comparable performance, and the flat plates were chosen as the design system due to their lower cost. A design system of 2300 m/sup 2/ flat plate collectors with heat pump was selected. The system provides a solar fraction of 50% for the 2167 MWH annual heat load. The annualized cost of the solar energy supplied is $66.60/MWH which is competitive with the conventional heating alternative for a conventional heating cost of $0.05/kWh. Considerations regarding the implementation and financing of this project are also discussed.

Breger, D.S.; Michaels, A.I.

1983-06-01

248

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

249

Underground natural gas storage in the United States 1979 - 1980 heating year  

NASA Astrophysics Data System (ADS)

Total gas in storage in the nation's active underground natural gas storage reservoirs as of March 31, 1980, the end of the 1979-1980 heating year, was reported at 5,129 billion cubic feet. Of this total, approximately 69.1 percent was base, or cushion, gas and 30.9 percent was working gas. Working gas totaled 1,586 billion cubic feet, approximately 28.2 percent above that available at the beginning of the heating year. The nation's 383 active storage reservoirs were operated by 77 companies. Total reservoir capacity was reported at 7,287 billion cubic feet, approximately 51.4 percent, or 3,744 billion cubic feet of which was working gas capacity. Approximately 67.9 percent of this working gas capacity was in 228 reservoirs operated by 30 interstate pipeline companies, 29.1 percent was in 142 reservoirs operated by 42 intrastate companies, and 3.1 percent was in 13 reservoirs operated by 5 independent producers.

1980-09-01

250

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

251

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

252

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

Microsoft Academic Search

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

Moon-Hyun Chun; Myeong-Gie Kang

1996-01-01

253

The mini-prototype solar energy earth storage system  

NASA Astrophysics Data System (ADS)

A one-tenth scale model of solar energy earth storage (SEES) system was tested under an artificial condition during the first winter season. The earth storage was heated by house hot water heaters and heat was then extracted with a high performance heat exchanger which was exposed to an open air environment under subfreezing temperatures. The results of these preliminary tests show that the thermal performance of the earth storage heat exchanger (polybutylene plastic coils) and the wet soil medium is quite satisfactory. Furthermore, the response rate of the earth storage to a large heat demand over a short-time duration is more than adequate.

Yuan, S. W.; Majdi, M. M.

1981-07-01

254

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

255

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

256

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

257

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

Microsoft Academic Search

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

Li Xiangling; Chen Chao; Ouyang Jun

258

Heat and mass transfer coefficients during the refrigeration, freezing and storage of meats, meat products and analogues  

Microsoft Academic Search

The existing bibliographical data on heat and mass transfer coefficients during refrigeration, freezing and storage of meat and meat products were reviewed.Heat transfer coefficients for meat balls and hamburgers were determined experimentally in a prototype belt freezer. Measurements were carried out at different air velocities and directions of air flow. In each case, the coefficients thus obtained were correlated with

A. M. Tocci; R. H. Mascheroni

1995-01-01

259

BWR spent fuel storage cask performance test. Volume 1. Cask handling experience and decay heat, heat transfer, and shielding data  

SciTech Connect

This report documents a heat transfer and shielding performance test conducted on a Ridihalgh, Eggers and Associates REA 2023 boiling water reactor (BWR) spent fuel storage cask. The testing effort consisted of three parts: pretest preparations, performance testing, and post-test activities. Pretest preparations included conducting cask handling dry runs and characterizing BWR spent fuel assemblies from Nebraska Public Power District's Cooper Nuclear Station. The performance test matrix included 14 runs consisting of two loadings, two cask orientations, and three backfill environments. Post-test activities included calorimetry and axial radiation scans of selected fuel assemblies, in-basin sipping of each assembly, crud collection, video and photographic scans, and decontamination of the cask interior and exterior.

McKinnon, M.A.; Doman, J.W.; Tanner, J.E.; Guenther, R.J.; Creer, J.M.; King, C.E.

1986-02-01

260

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

261

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

Microsoft Academic Search

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

Karabut

2004-01-01

262

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

SciTech Connect

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

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

1991-10-01

263

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

264

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

E-print Network

Heating Elements: 36-40 gage finely stranded resistance wire Heating Elements Insulation: Double braided fiberglass yarn Dielectric Strength: In excess of 2000V Lead Wires: 16 AWG high temperature 600V silicone rubber insulated lead wire emerging from opposite ends of the heating tape into separate sides

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

265

Simplification of methods for the production and storage of specimens to be tested for heat-stable enterotoxin of Escherichia coli.  

PubMed Central

Experiments with the infant mouse test demonstrated that there is no need of shaking for heat-stable Escherichia coli enterotoxin production when low volume of medium per volume of flask ratios are used in stationary cultures. Centrifugation and filtration of the cultures to be tested are not necessary either, and Merthiolate (1:10,000) used as preservative has no deleterious effect on heat-stable enterotoxin activity. Based upon these findings, some modifications of the procedures for production and storage of heat-stable enterotoxin preparations are suggested. Standardized pieces of filter papers are wetted with Merthiolated stationary cultures which are to be assayed for heat-stable enterotoxin activity by the infant mouse test. From dried filter papers, heat-stable enterotoxin can be eulted unaltered up to 2 months after specimen preparation. With the proposed modifications, even modestly equipped laboratories will be able to carry out the infant mouse test or at least to prepare specimens to be assayed by more specialized laboratories. PMID:391814

Gomes, J A; Rodrigues, A C; Simóes, M; Serafim, M B; De Castro, A F

1979-01-01

266

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

NASA Astrophysics Data System (ADS)

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

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

267

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

268

Development of a phase-change thermal storage system using modified anhydrous sodium hydroxide for solar electric power generation  

Microsoft Academic Search

A thermal storage system for use in solar power electricity generation was investigated analytically and experimentally. The thermal storage medium is principally anhydrous NaOH with 8% NaNO3 and 0.2% MnO2. Heat is charged into storage at 584 K and discharged from storage at 582 K by Therminol-66. Physical and thermophysical properties of the storage medium were measured. A mathematical simulation

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

1978-01-01

269

OPTIMIZATION OF INTERNAL HEAT EXCHANGERS FOR HYDROGEN STORAGE TANKS UTILIZING METAL HYDRIDES  

SciTech Connect

Two detailed, unit-cell models, a transverse fin design and a longitudinal fin design, of a combined hydride bed and heat exchanger are developed in COMSOL{reg_sign} Multiphysics incorporating and accounting for heat transfer and reaction kinetic limitations. MatLab{reg_sign} scripts for autonomous model generation are developed and incorporated into (1) a grid-based and (2) a systematic optimization routine based on the Nelder-Mead downhill simplex method to determine the geometrical parameters that lead to the optimal structure for each fin design that maximizes the hydrogen stored within the hydride. The optimal designs for both the transverse and longitudinal fin designs point toward closely-spaced, small cooling fluid tubes. Under the hydrogen feed conditions studied (50 bar), a 25 times improvement or better in the hydrogen storage kinetics will be required to simultaneously meet the Department of Energy technical targets for gravimetric capacity and fill time. These models and methodology can be rapidly applied to other hydrogen storage materials, such as other metal hydrides or to cryoadsorbents, in future work.

Garrison, S.; Tamburello, D.; Hardy, B.; Anton, D.; Gorbounov, M.; Cognale, C.; van Hassel, B.; Mosher, D.

2011-07-14

270

Development of approximate method to analyze the characteristics of latent heat thermal energy storage system  

SciTech Connect

Third Conference of the Parties to the U.N. Framework Convention on Climate Change (COP3) held in last December in Kyoto urged the industrialized nation to reduce carbon dioxide (CO{sub 2}) emissions by 5.2 percent (on the average) below 1990 level until the period between 2008 and 2012 (Kyoto protocol). This implies that even for the most advanced countries like the US, Japan, and EU implementation of drastic policies and overcoming many barriers in market should be necessary. One idea which leads to a path of low carbon intensity is to adopt an energy storage concept. One of the reasons that the efficiency of the conventional energy systems has been relatively low is ascribed to lacking of energy storage subsystem. Most of the past energy systems, for example, air-conditioning system, do not have energy storage part and the system usually operates with low energy efficiency. Firstly, the effect of reducing CO{sub 2} emissions was also examined if the LHTES subsystems were incorporated in all the residential and building air-conditioning systems. Another field of application of the LHTES is of course transportation. Future vehicle will be electric or hybrid vehicle. However, these vehicles will need considerable energy for air-conditioning. The LHTES system will provide enough energy for this purpose by storing nighttime electricity or rejected heat from the radiator or motor. Melting and solidification of phase change material (PCM) in a capsule is of practical importance in latent heat thermal energy storage (LHTES) systems which are considered to be very promising to reduce a peak demand of electricity in the summer season and also reduce carbon dioxide (CO{sub 2}) emissions. Two melting modes are involved in melting in capsules. One is close-contact melting between the solid bulk and the capsule wall, and another is natural convection melting in the liquid (melt) region. Close-contact melting processes for a single enclosure have been solved using several numerical methods (e.g. Saitoh and Kato, 1994). In addition, close-contact melting heat transfer characteristics including melt flow in the liquid film under inner wall temperature distribution were analyzed and simple approximate equations were already presented by Saitoh and Hoshi (1997). In this paper, the authors will propose an analytical solution on combined close-contact and natural convection melting in horizontal cylindrical and spherical capsules, which is useful for the practical capsule bed LHTES system.

Saitoh, T.S.; Hoshi, Akira

1999-07-01

271

Finite element method for radiation heat transfer in multi-dimensional graded index medium  

Microsoft Academic Search

In graded index medium, ray goes along a curved path determined by Fermat principle, and curved ray-tracing is very difficult and complex. To avoid the complicated and time-consuming computation of curved ray trajectories, a finite element method based on discrete ordinate equation is developed to solve the radiative transfer problem in a multi-dimensional semitransparent graded index medium. Two particular test

L. H. Liu; L. Zhang; H. P. Tan

2006-01-01

272

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

273

Conductive heat flow anomalies over a hot spot in a moving medium  

Microsoft Academic Search

In the model the hot spot is represented by a point source of heat in an infinite half space moving uniformly in the x direction with velocity U (z is positive downward; y is horizontal and normal to motion). Only steady state conductive heat transfer is considered. The upper boundary condition, zero surface temperature, is satisfied by addition of a

Francis S. Birch

1975-01-01

274

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

SciTech Connect

Large scale thermal energy storage for solar heating applications can be accomplished in the ground through the installation of an array of vertical heat exchange boreholes or U-tubes. Simulation modeling of the storage subsystem and its integration with the total system is essential for design and performance evaluation. Although U-tube storage design is especially attractive in clay soils and preferable to boreholes in many geological conditions, only a borehole simulation model is currently available, validated, and integrated into a system simulation model. This article presents a comparative analysis of the heat transfer from boreholes and U-tubes using analytical solutions, finite element modeling, and the available simulation model. The analysis is used to support the development of a methodology by which the heat transfer of any U-tube configuration can be modeled by appropriately specifying parameters in the borehole storage simulation model. The borehole model can then be used to model the storage subsystem integrated within a total system simulation model. 12 refs., 8 figs.

Breger, D.S. [Lafayette College, Easton, PA (United States)] [Lafayette College, Easton, PA (United States); Hubbell, J.E.; Hasnaoui, H.E.; Sunderland, J.E. [Univ. of Massachussetts, Amherst, MA (United States)] [Univ. of Massachussetts, Amherst, MA (United States)

1996-06-01

275

S{sub n} solutions for radiative heat transfer in an L-shaped participating medium  

SciTech Connect

The Third Symposium on Solution Methods for Radiative Heat Transfer in Participating Media is a continuing effort to benchmark solutions for problems of increasing complexity. This paper presents both the statement of a problem used for the benchmarking exercise and the results obtained using a finite-element S{sub 4} solution. Cases analyzed include rectangular and L-shaped enclosures, and homogeneous and nonhomogeneous media. Calculated surface radiative heat fluxes and divergence of radiative heat fluxes are tabulated at selected coordinates within the evaluated enclosures. Computation times for each of the solutions were recorded and are presented to permit a computational efficiency test against other solution techniques.

Hoover, R.L.; Li, W.; Benmalek, A.; Tong, T.W. [Arizona State Univ., Tempe, AZ (United States). Dept. of Mechanical and Aerospace Engineering

1996-11-01

276

Performance of heat charge\\/discharge of magnesium nitrate hexahydrate and magnesium chloride hexahydrate mixture to a single vertical tube for a latent heat storage system  

Microsoft Academic Search

The authors focused on a mixture of magnesium nitrate hexahydrate as a base material and magnesium chloride hexahydrate as an additive to store and utilize urban waste heat from emerged co-generation systems, typically available at temperatures of 60–90 °C. The second paper revealed that this mixture has good thermal characteristics as a PCM for latent thermal energy storage. In this

K Nagano; K Ogawa; T Mochida; K Hayashi; H Ogoshi

2004-01-01

277

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

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

278

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

NASA Astrophysics Data System (ADS)

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 size, population and built-up structure of settlements. Meteorological conditions have a determinant impact on the development of the heat island at a certain moment. International and Hungarian studies usually deal with metropolises and big cities; much less attention is paid to medium-sized and small towns. Consequently this study has been focused on the development of UHI in such Hungarian urbanized areas as mentioned above. Settlements, located near the city of Debrecen (ca. 220,000 inhabitants) in East Hungary, with population of about 30000, 20000 10000 and 1000 were chosen for the research. Car-mounted digital thermometers with data loggers were used. Twenty four measurements were carried out during a one-year-long campaign in 2003-2004. Synoptic conditions, especially cloudiness, wind direction and wind speed were taken to consideration as determinant factors. Spatial characteristics of UHI have been described. Results have proved the existence of UHI even in the smallest settlement under suitable weather conditions. The non-heating season proved to be more advantageous for the development of UHI due to stronger irradiance and frequent anticyclonic synoptic conditions. Effects of cloudiness and wind speed have been revealed as well. St type clouds have proved to be most effective in preventing the formation of UHI. A 90-100% St cover could completely eliminate the thermal differences between natural and artificial surfaces. Ci type clouds had the weakest impact, they could prevent the formation of the heat island only in the smallest settlement involved in the study. In that cases when favorable synoptic conditions prevailed within 48-72 hours before the measurements, but during the measuring cloudiness reached 50%, strong UHI could not develop in any settlement, while over 75% only weak UHI could form in the big city. Over 90% there were no heat island found in any settlements involved here. Wind speed had a strong impact on the strength of the heat island, while wind directions affected its shape merely. It was found that winds of 1-1.5 m/s (measured at a height of 2 metres) could prevent the formation of an UHI in settlements with 10000 inhabitants and below. In such cases in settlements with 20000-300000 inhabitants, only medium intensity heat islands could develop, and the intensity curve became asymmetric as the heat island was pushed towards the lee side. In case of stronger 2.5-3 m/s winds, UHI could develop only in Debrecen. The intensity in such cases (2-3 °C) reached only about half of the characteristic intensity of ideal circumstances. The shape was usually drifted strongly lee wards. Over a wind speed 3 m/s, at a height of 2 m heat island could not develop in any settlements involved in the study.

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

2010-09-01

279

Thermal conductivity and latent heat thermal energy storage characteristics of paraffin\\/expanded graphite composite as phase change material  

Microsoft Academic Search

This study aimed determination of proper amount of paraffin (n-docosane) absorbed into expanded graphite (EG) to obtain form-stable composite as phase change material (PCM), examination of the influence of EG addition on the thermal conductivity using transient hot-wire method and investigation of latent heat thermal energy storage (LHTES) characteristics of paraffin such as melting time, melting temperature and latent heat

Ahmet Sar?; Ali Karaipekli

2007-01-01

280

Numerical prediction of heat transfer by natural convection and radiation in an enclosure filled with an isotropic scattering medium  

NASA Astrophysics Data System (ADS)

This paper deals with the numerical solution for natural convection and volumetric radiation in an isotropic scattering medium within a heated square cavity using a hybrid thermal lattice Boltzmann method (HTLBM). The multiple relaxation time lattice Boltzmann method (MRT-LBM) has been coupled to the finite difference method (FDM) to solve momentum and energy equations, while the discrete ordinates method (DOM) has been adopted to solve the radiative transfer equation (RTE) using the S8 quadrature. Based on these approaches, the effects of various influencing parameters such as the Rayleigh number (Ra), the wall emissivity (??), the Planck number (Pl), and the scattering albedo (?), have been considered. The results presented in terms of isotherms, streamlines and averaged Nusselt number, show that in absence of radiation, the temperature and the flow fields are centro-symmetrics and the cavity core is thermally stratified. However, radiation causes an overall increase in the temperature and velocity gradients along both thermally active walls. The maximum heat transfer rate is obtained when the surfaces of the enclosure walls are regarded as blackbodies. It is also seen that the scattering medium can generate a multicellular flow.

Moufekkir, F.; Moussaoui, M. A.; Mezrhab, A.; Naji, H.; Lemonnier, D.

2012-09-01

281

Effect of various heat treatments and cold storage on sulphamethazine residues stability in incurred piglet muscle and cow milk samples  

Microsoft Academic Search

The stability of sulphamethazine (SMZ) residues in incurred piglets muscle tissue and incurred cow milk, under various heat treatments (pasteurizing, boiling, autoclaving and microwaving) was studied. Moreover, the storage stability of SMZ residues at ?20 and ?75°C as well as the stability of SMZ standard solutions under boiling and autoclaving conditions was also investigated. The results showed that in the

E. P. Papapanagiotou; D. J. Fletouris; E. I. Psomas

2005-01-01

282

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

Microsoft Academic Search

This report documents the design development and selection of the final preliminary design of a Central Solar Heating Plant with Seasonal Storage (CSHPSS) for the University of Massachusetts in Amherst (UMass). The effort has been performed by the Department of Mechanical Engineering at UMass under contract with the U.S. Department of Energy. Phase 1 of this project was directed at

D. S. Breger; J. E. Sunderland

1991-01-01

283

Fluid Flow, Heat Transfer, and Solute Transport at Nuclear Waste Storage Tanks in the Hanford Vadose Zone  

Microsoft Academic Search

At the Hanford site, highly radioactive and chemically aggressive waste fluids have leaked from underground storage tanks into the vadose zone. This paper addresses hydrogeological issues at the 241-SX tank farm, especially focusing on tank SX-108 which is one of the highest heat load, supernate density and ionic strength tanks at Hanford and a known leaker. The behavior of contaminants

Karsten Pruess; Steven B. Yabusaki; Carl I. Steefel; Peter C. Lichtner

2002-01-01

284

Encapsulated Fatty Acids in an Acrylic Resin as Shape-stabilized Phase Change Materials for Latent Heat Thermal Energy Storage  

Microsoft Academic Search

This article aims to prepare novel shape-stabilized phase change materials (PCMs) by encapsulating fatty acids (stearic acid [SA], palmitic acid [PA], and myristic acid [MA]) as a PCM in an acrylic resin (Eudragit E) as supporting material and to determine latent heat thermal energy storage (LHTES) properties. The maximum percentage of all fatty acids in the shape-stabilized PCMs was found

K. Kaygusuz; C. Alkan; A. Sari; O. Uzun

2008-01-01

285

Thermal reliability test of some fatty acids as PCMs used for solar thermal latent heat storage applications  

Microsoft Academic Search

The purpose of this study is to determine the thermal reliability of stearic acid, palmitic acid, myristic acid and lauric acid as latent heat energy storage materials with respect to various numbers of thermal cycles. The fatty acids, as phase change materials (PCMs), of industrial grade (purity between 90% and 97%) were subjected to accelerated thermal cycle tests. The differential

Ahmet Sar?

2003-01-01

286

Correlation of the volumetric heat transfer coefficient for air-rock bed thermal storage system - considering humid air  

Microsoft Academic Search

Rock bed thermal storage with humid air green house or regenerative air cooling application are becoming widely investigated nowadays. The effect of the mass transfer in the circulated air has not received much attention. In this experimental study, the effect of the mass in the operated air is studied and new correlation for calculating the coefficient of volumetric heat transfer

P. Achard; A. Ayoob; L. Elegant

1990-01-01

287

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

Microsoft Academic Search

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

A. M. Tocci; R. H. Mascheroni

1995-01-01

288

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

289

Net surface heat flux over the North and South Atlantic in 1985-1986 from Day 1 predictions of the European Center for Medium Range Weather Forecast  

Microsoft Academic Search

Twelve months of data on surface heat fluxes (shortwave radiation, longwave radiation, latent heat and sensible heat, from August 1985 to July 1986), obtained from the European Center for Medium-Range Weather Forecast (ECMWF) on a grid of 1.125° latitude by 1.125° longitude were analyzed. Comparison with older data from ECMWF (Simonot and Le Treut, 1987) indicates the occurrence of significant

B. Barnier; J.-Y. Simonot

1990-01-01

290

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

SciTech Connect

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

Kingston, T.; Scott, S.

2013-03-01

291

Energy storage  

NASA Astrophysics Data System (ADS)

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

Kaier, U.

1981-04-01

292

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

NASA Astrophysics Data System (ADS)

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

O'Sullivan, Ewan

2014-09-01

293

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

294

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

PubMed

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 (D2)) 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 this study spanned a broad range of height (13.5-58 m) and diameter (0.14-1.43 m). Sap flow was monitored continuously with heat dissipation probes near the base of the trunk prior to, during and following injection of D2O. The transit time for D2O transport from the base of the trunk to the upper crown and the tracer residence time were determined by measuring hydrogen isotope ratios in water extracted from leaves sampled at regular intervals. Transit times for arrival of D2O in the upper crown ranged from 2.5 to 21 d and residence times ranged from 36 to 79 d. Estimates of maximum sap velocity derived from tracer transit times and path length ranged from 2.4 to 5.4 m d(-1). Tracer residence time and half-life increased as tree diameter increased, independent of species. Species-independent scaling of tracer velocity with sapwood-specific conductivity was also observed. When data from this study were combined with similar data from an earlier study of four tropical angiosperm trees, species-independent scaling of tracer velocity and residence time with sapwood hydraulic capacitance was observed. Sapwood capacitance is an intrinsic tissue-level property that appears to govern whole-tree water transport in a similar manner among both tracheid- and vessel-bearing species. PMID:17086757

Meinzer, F C; Brooks, J R; Domec, J C; Gartner, B L; Warren, J M; Woodruff, D R; Bible, K; Shaw, D C

2006-01-01

295

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

296

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

297

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

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

298

Unsteady boundary layer MHD free convection flow in a porous medium with constant mass diffusion and Newtonian heating  

NASA Astrophysics Data System (ADS)

In this article, the unsteady boundary layer magnetohydrodynamic (MHD) free convection flow past an oscillating vertical plate embedded in a porous medium with constant mass diffusion and Newtonian heating condition is analysed. By considering the effects of thermal radiation in the energy equation, the problem is first modeled and then written in dimensionless form, which is then solved by using the Laplace transform technique. The expressions for velocity, temperature and concentration fields are obtained and plotted graphically to see the influence of embedded parameters. The results for skin friction, Nusselt number and Sherwood number are also shown in tables. Further a table is included for the comparison of our results with those present in the literature.

Hussanan, Abid; Ismail, Zulkhibri; Khan, Ilyas; Hussein, Atheer G.; Shafie, Sharidan

2014-03-01

299

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

300

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

SciTech Connect

Plant toxicity threshold levels of several heat transfer and storage fluids and eutectic salts were determined by using a modified Neubauer technique. Barley seed germination and seedling growth were used for the toxicity tests. The general order of toxicity of the fluids applied to three mineral soils was ethylene gloycol > Dow 200 much greater than Caloria HT43 > Therminol 66. The toxicity order of the fluids applied to an organic soil was ethylene glycol > Caloria HT43 > Dow 200 > Therminol 66. Thus, Therminol 66 was the least toxic among the fluids used. Among the eutectic salts tested Dupont HITEC was more toxic than 8.4 percent NaCl-86.3 percent NaNO/sub 3/-5.3 percent Na/sub 2/SO/sub 4/ mixture in three of the four soils used. In the fourth soil there was no apparent difference of toxicity between the two salt mixtures. Depending on the fluid and the salt mixture, the toxicity threshold levels for barley seedlings ranged from 4451 to 317,488 ppM in the soils used.

Nishita, H.

1980-10-01

301

Enrichment and heating of the intracluster medium by ejection from galaxies  

NASA Technical Reports Server (NTRS)

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

Metzler, Chris; Evrard, August

1993-01-01

302

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

PubMed

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

Masegosa, Rosa; Delgado-Adámez, Jonathan; Contador, Rebeca; Sánchez-Íñiguez, Francisco; Ramírez, Rosario

2014-12-01

303

Mineralization of carbon during moist incubation of soil JF79 treated with organic heat-transfer and storage fluids  

Microsoft Academic Search

Biodegradability of four heat transfer\\/storage fluids (ethylene glycol, Therminol 66, Caloria HT43, and Dow Corning Fluid No. 200) were examined. The degradation was monitored by periodically measuring the mineralization of carbon in moist fluid-contaminated soils incubated at 28° and 37°C for 8 weeks. Ethylene glycol mineralized relatively readily. The other three fluids did not show measurable amount of carbon mineralization

H. Nishita; R. M. Haug

1981-01-01

304

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

PubMed

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

Endo, Akihito; Teräsjärvi, Johanna; Salminen, Seppo

2014-03-17

305

New Carbon-Based Porous Materials with Increased Heats of Adsorption for Hydrogen Storage  

SciTech Connect

Hydrogen fuel cell vehicles are a promising alternative to internal combustion engines that burn gasoline. A significant challenge in developing fuel cell vehicles is to store enough hydrogen on-board to allow the same driving range as current vehicles. One option for storing hydrogen on vehicles is to use tanks filled with porous materials that act as “sponges” to take up large quantities of hydrogen without the need for extremely high pressures. The materials must meet many requirements to make this possible. This project aimed to develop two related classes of porous materials to meet these requirements. All materials were synthesized from molecular constituents in a building-block approach, which allows for the creation of an incredibly wide variety of materials in a tailorable fashion. The materials have extremely high surface areas, to provide many locations for hydrogen to adsorb. In addition, they were designed to contain cations that create large electric fields to bind hydrogen strongly but not too strongly. Molecular modeling played a key role as a guide to experiment throughout the project. A major accomplishment of the project was the development of a material with record hydrogen uptake at cryogenic temperatures. Although the ultimate goal was materials that adsorb large quantities of hydrogen at room temperature, this achievement at cryogenic temperatures is an important step in the right direction. In addition, there is significant interest in applications at these temperatures. The hydrogen uptake, measured independently at NREL was 8.0 wt %. This is, to the best of our knowledge, the highest validated excess hydrogen uptake reported to date at 77 K. This material was originally sketched on paper based on a hypothesis that extended framework struts would yield materials with excellent hydrogen storage properties. However, before starting the synthesis, we used molecular modeling to assess the performance of the material for hydrogen uptake. Only after modeling suggested record-breaking hydrogen uptake at 77 K did we proceed to synthesize, characterize, and test the material, ultimately yielding experimental results that agreed closely with predictions that were made before the material was synthesized. We also synthesized, characterized, and computationally simulated the behavior of two new materials displaying the highest experimental Brunauer?Emmett?Teller (BET) surface areas of any porous materials reported to date (?7000 m2/g). Key to evacuating the initially solvent-filled materials without pore collapse, and thereby accessing the ultrahigh areas, was the use of a supercritical CO2 activation technique developed by our team. In our efforts to increase the hydrogen binding energy, we developed the first examples of “zwitterionic” metal-organic frameworks (MOFs). The two structures feature zwitterionic characteristics arising from N-heterocyclic azolium groups in the linkers and negatively charged Zn2(CO2)5 nodes. These groups interact strongly with the H2 quadrupole. High initial isosteric heats of adsorption for hydrogen were measured at low H2 loading. Simulations were used to determine the H2 binding sites, and results were compared with inelastic neutron scattering. In addition to MOFs, the project produced a variety of related materials known as porous organic frameworks (POFs), including robust catechol-functionalized POFs with tunable porosities and degrees of functionalization. Post-synthesis metalation was readily carried out with a wide range of metal precursors (CuII, MgII, and MnII salts and complexes), resulting in metalated POFs with enhanced heats of hydrogen adsorption compared to the starting nonmetalated materials. Isosteric heats of adsorption as high as 9.6 kJ/mol were observed, compared to typical values around 5 kJ/mol in unfunctionalized MOFs and POFs. Modeling played an important role throughout the project. For example, we used molecular simulations to determine that the optimal isosteric heat of adsorption (Qst) for maximum hydrogen delivery using MOFs is appro

Snurr, Randall Q.; Hupp, Joseph T.; Kanatzidis, Mercouri G.; Nguyen, SonBinh T.

2014-11-03

306

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

307

Efficient Phase-Change Materials: Development of a Low-Cost Thermal Energy Storage System Using Phase-Change Materials with Enhanced Radiation Heat Transfer  

SciTech Connect

HEATS Project: USF is developing low-cost, high-temperature phase-change materials (PCMs) for use in thermal energy storage systems. Heat storage materials are critical to the energy storage process. In solar thermal storage systems, heat can be stored in these materials during the day and released at night—when the sun is not out—to drive a turbine and produce electricity. In nuclear storage systems, heat can be stored in these materials at night and released to produce electricity during daytime peak-demand hours. Most PCMs do not conduct heat very well. Using an innovative, electroless encapsulation technique, USF is enhancing the heat transfer capability of its PCMs. The inner walls of the capsules will be lined with a corrosion-resistant, high-infrared emissivity coating, and the absorptivity of the PCM will be controlled with the addition of nano-sized particles. USF’s PCMs remain stable at temperatures from 600 to 1,000°C and can be used for solar thermal power storage, nuclear thermal power storage, and other applications.

None

2011-12-05

308

Evaluation of a simple and cost effective filter paper-based shipping and storage medium for environmental sampling of F-RNA coliphages.  

PubMed

Male specific RNA (F-RNA) coliphages are used as indicators of fecal contamination and for source tracking. However, collecting fecal samples for analysis from remote sites is problematic due to the need for an uninterrupted cold chain to guarantee sample suitability for downstream molecular detection of these coliphages. Here, we investigated the feasibility of using filter paper as a collection and storage vehicle for F-RNA coliphages. Various concentrations (10(1) to 10(4)pfu) of two F-RNA coliphages, MS2 and Q?, were prepared in lambda buffer or a 10% bovine manure slurry, spotted onto filter paper disks, dried, and maintained at 37 °C for up to 37 days. Nucleic acids were extracted from the spotted filter paper disks at 0, 6, 13, and 37 days post inoculation and analyzed by real time RT-PCR. F-RNA coliphages at concentrations of 10(2)pfu/filter paper unit were readily detected, and only a slight decrease in nucleic acid detection was observed over time. Furthermore, the sensitivity of real time RT-PCR detection of the F-RNA coliphage RNA was similar between the developed filter paper sampling methodology and traditional cold storage. These results indicate that filter paper is a suitable storage and transport medium for F-RNA coliphages when refrigeration is not possible. PMID:23954843

Pérez-Méndez, A; Chandler, J C; Bisha, B; Coleman, S M; Zhanqiang, S; Gang, Y; Goodridge, L D

2013-12-01

309

Experimental investigation on heat recovery from diesel engine exhaust using finned shell and tube heat exchanger and thermal storage system  

Microsoft Academic Search

The exhaust gas from an internal combustion engine carries away about 30% of the heat of combustion. The energy available in the exit stream of many energy conversion devices goes as waste, if not utilized properly. The major technical constraint that prevents successful implementation of waste heat recovery is due to its intermittent and time mismatched demand and availability of

V. Pandiyarajan; M. Chinna Pandian; E. Malan; R. Velraj; R. V. Seeniraj

2011-01-01

310

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

NASA Astrophysics Data System (ADS)

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

Watanabe, O.; Tanaka, M.

311

Comparison between two common collocation approaches based on radial basis functions for the case of heat transfer equations arising in porous medium  

Microsoft Academic Search

In this paper two common collocation approaches based on radial basis functions have been considered; one be computed through the integration process (IRBF) and one be computed through the differentiation process (DRBF). We investigated the two approaches on natural convection heat transfer equations embedded in porous medium which are of great importance in the design of canisters for nuclear wastes

K. Parand; S. Abbasbandy; S. Kazem; A. R. Rezaei

2011-01-01

312

On MHD boundary-layer flow and mass transfer past a vertical plate in a porous medium with constant heat flux  

Microsoft Academic Search

Purpose – The hydromagnetic mixed convection flow of an incompressible viscous electrically conducting fluid and mass transfer over a vertical porous plate with constant heat flux embedded in a porous medium is investigated. Design\\/methodology\\/approach – Using the Boussinesq and boundary-layer approximations, the fluid equations for momentum, energy balance and concentration governing the problem are formulated. These equations are solved numerically

O. D. Makinde

2009-01-01

313

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

314

Advanced high-temperature molten-salt storage research  

SciTech Connect

We are researching advanced high-temperature molten-salt thermal storage for use in direct absorption receiver and thermal storage (DARTS) solar thermal systems. A molten salt at 900/sup 0/C or higher is both the receiver heat transfer medium and the storage medium; a unique insulated platform (raft) separates the hot and cold medium in the thermocline thermal storage. We have measured raft performance experimentally, and it performs equally or better than a natural thermocline. Containment materials for the molten salts ae being experimentally screened. NaOH has a very high corrosion rate on ceramics and metals. Both carbonates and chlorides can be contained at 900/sup 0/C with relatively little corrosion. Based on the measured corrosion rates, the economic potential of molten-salt thermal storage was analyzed. Both the chlorides and carbonates have potential (i.e., cost less than value) at the capacity of storage expected for commercial-scale solar thermal systems.

Copeland, R.J.; Coyle, R.T.

1983-08-01

315

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

316

Preliminary design study of a Central Solar Heating Plant with Seasonal Storage at the University of Massachusetts, Amherst  

SciTech Connect

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 US 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 a 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{sup 2} parabolic trough collector array, 70,000 m{sup 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% 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. 23 figs., 20 tabs.

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

1991-04-01

317

Quality of cut lettuce treated by heat shock: prevention of enzymatic browning, repression of phenylalanine ammonia-lyase activity, and improvement on sensory evaluation during storage.  

PubMed

Stored cut lettuce gradually turns brown on the cut section after several days of storage, because cutting induces phenylalanine ammonia-lyase (PAL) activity, the biosynthesis of polyphenol is promoted, and the polyphenols are oxidized by polyphenol oxidase. Here, the effect of heat shock treatment at 50 degrees C for 90 s on the quality of cut lettuce during cold storage was examined. The heat shock treatment significantly repressed the induction of PAL activity and phenolics accumulation in cut lettuce during storage, and prevented the browning of cut lettuce. Ascorbic acid content was not affected by the heat shock treatment. The sensory analysis showed that the organoleptic quality of cut lettuce treated by heat shock was significantly better than that of the control cut lettuce. These results show that heat shock treatment is useful for prolonging the shelf life of cut lettuce. PMID:15056879

Murata, Masatsune; Tanaka, Eriko; Minoura, Emiko; Homma, Seiichi

2004-03-01

318

Vertical profiles and storage fluxes of CO2, heat and water in a tropical rainforest at Pasoh, Peninsular Malaysia  

NASA Astrophysics Data System (ADS)

Ambient CO2 concentration, air temperature and relative humidity were measured intermittently for a 3-year period from the floor to the canopy top of a tropical rainforest in Pasoh, Peninsular Malaysia. Mean diurnal CO2 storage flux (Sc; ?mol m-2 s-1) and sensible and latent heat storage fluxes (Qa and Qw; W m-2) ranged from -12.7 to 3.2 ?mol m-2 s-1, -15 to 27 W m-2 and -10 to 20 W m-2, respectively. Small differences in diurnal changes were observed in Sc and Qa between the driest and wettest periods. Compared with the ranges of mean diurnal CO2 eddy flux (-14.7 to 4.9 ?mol m-2 s-1), sensible eddy flux (-12 to 169 W m-2) and latent eddy flux (0 to 250 W m-2), the contribution of CO2 storage flux was especially large. Comparison with summertime data from a temperate Japanese cypress forest suggested a higher contribution of Sc in the tropical rainforest, probably mainly due to the difference in nighttime friction velocity at the sites. On the other hand, differences in Qa and Qw were smaller than the difference in Sc, probably because of the smaller nighttime sinks/sources of heat and water vapour.

Ohkubo, Shinjiro; Kosugi, Yoshiko; Takanashi, Satoru; Matsuo, Naoko; Tani, Makoto; Nik, Abdul Rahim

2008-09-01

319

Study of Underfloor Electric Heating System with Latent Thermal Storage and Ductless Air Supply  

Microsoft Academic Search

This paper puts forward a new kind of under-floor electric heating system with phase change material (PCM) plates with ductless air supply. Different from conventional PCM, shape-stabilized PCM can keep the shape unchanged during phase change process. Therefore, the PCM leakage danger can be avoided. The system can charge heat by using cheap nighttime electricity and discharge the heat stored

Kunping Lin; Yinping Zhang; Hongfa Di; Jianhong Ding; Rui Yang; Xu Xu

320

Synthesis and effect of electrode heat-treatment on the superior lithium storage performance of Co3O4 nanoparticles  

NASA Astrophysics Data System (ADS)

Single-crystal Co3O4 nanoparticles are produced via a novel lysine-assisted hydrothermal process. When used as anode materials for lithium-ion batteries, a heat-treatment process is first introduced to decrease the initial irreversible loss and enhance the cyclability of Co3O4 nanoparticle-based electrodes using a polyvinylidene fluoride (PVDF) binder. Heat-treated electrodes exhibit improved lithium storage properties relative to those that are unheated. In particular, Co3O4 electrodes heated at 200 °C have the highest capacity and best reversibility: 1000 mA h g-1 with 95.2% capacity retention after 170 cycles at a current density of 100 mA g-1. Even when cycled at a high rate of 1000 mA g-1, a reversible capacity up to 600 mA h g-1 can still be maintained after 500 cycles. These improvements are explained based on the results from thermal analysis, transmission electron microscopy, scanning electron microscopy, nanoscratch tests, and electrochemical impedance spectroscopy measurements. Heat treatment not only improves binder distribution and adhesion to both Co3O4 particles and the substrate but also ensures high interfacial conductivity and keeps the active material particles and carbon black electrically connected, thereby leading to superior electrochemical performance. The results suggest that the heat-treated Co3O4 electrode may be a promising anode for next-generation lithium-ion batteries.

Zhang, Jingjing; Huang, Tao; Yu, Aishui

2015-01-01

321

Mineralization of carbon during moist incubation of soil JF79 treated with organic heat-transfer and storage fluids  

SciTech Connect

Biodegradability of four heat transfer/storage fluids (ethylene glycol, Therminol 66, Caloria HT43, and Dow Corning Fluid No. 200) were examined. The degradation was monitored by periodically measuring the mineralization of carbon in moist fluid-contaminated soils incubated at 28/sup 0/ and 37/sup 0/C for 8 weeks. Ethylene glycol mineralized relatively readily. The other three fluids did not show measurable amount of carbon mineralization during the experimental period. This implies potential long term environmental effects of mismanaged or accidental releases of these fluids into natural environment.

Nishita, H.; Haug, R.M.

1981-01-01

322

Thermal performance of phase change material energy storage floor for active solar water-heating system  

Microsoft Academic Search

The conventional active solar water-heating floor system contains a big water tank to store energy in the day time for heating\\u000a at night, which takes much building space and is very heavy. In order to reduce the water tank volume or even cancel the tank,\\u000a a novel structure of an integrated water pipe floor heating system using shapestabilized phase change

Ruolang Zeng; Xin Wang; Wei Xiao; Yinping Zhang; Qunli Zhang; Hongfa Di

2010-01-01

323

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

E-print Network

= air mass flow rate [lb/min], QT = total heat stored/removed during test [BTU), C = specific heat for air [BTU/lb 'F], and P m QL = net heat loss during the test run period [BTU/min). ATTS 4t represents the energy change in the air as it passed... Chloride (Nood) Figure 3. 3 Comparison of Heat Transfer Coefficients to Previous Research 34 CEivlENT I'MORTAR i OVi FLGA/t ON TFNPERATURF BOI 88 I 87 A ; 84$ R I 83 ' F 82) 80-', 4 78 IO 20 30 40 80 80 70 80 90 l00 ilO l20 TINE IN ii...

Wood, Stanley Clayton

1982-01-01

324

An experimental and numerical investigation of heat transfer during technical grade paraffin melting and solidification in a shell-and-tube latent thermal energy storage unit  

Microsoft Academic Search

The latent thermal energy storage system of the shell-and-tube type during charging and discharging has been analysed in this paper. An experimental and numerical investigation of transient forced convective heat transfer between the heat transfer fluid (HTF) with moderate Prandtl numbers and the tube wall, heat conduction through the wall and solid–liquid phase change of the phase change material (PCM),

Anica Trp

2005-01-01

325

Conventional versus storage phosphor-plate digital images to visualize the root canal system contrasted with a radiopaque medium.  

PubMed

The pulp tissue was removed from 20 mandibular first molar teeth using 2.5% NaOCl irrigation and hand files. The dried canals were infused with radiopaque contrast medium. Standardized conventional and Digora digital images were obtained of each tooth positioned in a dried mandible at 0- and 30-degree horizontal angulations. Three evaluators rated the image clarity of the 0- and 30-degree original, enhanced, three-dimensional, zoom, and reverse digital image modes as superior, equal, or inferior to corresponding 0- and 30-degree conventional radiographs. The ratings were compared using the Wilcoxon signed rank test. The original, three-dimensional, zoom, or reverse digital images were inferior to the conventional radiographs for clarity of canal anatomy. The enhanced digital images were not always inferior to the conventional radiographs and were the only images superior to the original digital images. Overall, evaluators rated the image clarity of root canal anatomy on conventional radiographs better than on Digora images. However, factors in the experimental design may have contributed to this result. PMID:12775009

Naoum, Hani J; Chandler, Nicholas P; Love, Robert M

2003-05-01

326

An inverse problem of parameter estimation for time-fractional heat conduction in a composite medium using carbon-carbon experimental data  

NASA Astrophysics Data System (ADS)

In this paper, a time-fractional heat conduction problem is mathematically proposed for an experimental heat conduction process in a 3-layer composite medium. A numerical solution to the direct problem is obtained with finite difference method. In regard to the inverse problem, the optimal order of Caputo fractional derivative is estimated with Levenberg-Marquardt method. Comparing with the carbon-carbon experimental data, the results show that the time-fractional heat conduction model provides an effective and accurate simulation of the experimental data. The rationality of the proposed time-fractional model and validity of Levenberg-Marquardt method in solving the time-fractional inverse heat conduction problem are also manifested according to the results. By conducting the sensitivity analysis, the feasibility of the parameter estimation is further discussed.

Zhuang, Qiao; Yu, Bo; Jiang, Xiaoyun

2015-01-01

327

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

328

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

329

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

SciTech Connect

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

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

2010-08-15

330

Influence of heat treatment in an oxidizing medium on the properties of copper-zinc-chromium-aluminum oxide catalyst for dehydrogenation of cyclohexanol  

Microsoft Academic Search

The authors report the results of a study of changes in the structure and catalytic properties of a copper-zinc-chromium-aluminum (CuZnCrAl) oxide catalyst, used for dehydrogenation of cyclohexanol, under the influence of heat treatment in an oxidizing medium. A catalyst of the composition (mass %): CuO 54.0, ZnO 12.0, CrâOâ 11.0, AlâOâ 20.0, the rest being graphite, was prepared by the

F. Kh. Sapozhnikova; V. Z. Fridman; I. Ya. Petrov; T. S. Polovkina; E. A. Kriventsova

1988-01-01

331

Shell-and-tube type latent heat thermal energy storage: numerical analysis and comparison with experiments  

NASA Astrophysics Data System (ADS)

The melting process of industrial grade paraffin wax inside a shell-and-tube storage is analyzed by means of numerical simulation and experimental results. For this purpose, the enthalpy porosity method is extended by a continuous liquid fraction function. The extended method is tested using results gained from a gallium melt test inside a rectangular enclosure.

Rösler, Fabian; Brüggemann, Dieter

2011-08-01

332

A new method of efficient heat transfer and storage at very high temperatures  

NASA Technical Reports Server (NTRS)

A unique, high temperature (1000-2000 K) continuously operating capacitive heat exchanger system is described. The system transfers heat from a combustion or solar furnace to a working gas by means of a circulating high temperature molten refractory. A uniform aggregate of beads of a glass-like refractory is injected into the furnace volume. The aggregate is melted and piped to a heat exchanger where it is sprayed through a counter-flowing, high pressure working gas. The refractory droplets transfer their heat to the gas, undergoing a phase change into the solid bead state. The resulting high temperature gas is used to drive a suitable high efficiency heat engine. The solidified refractory beads are delivered back to the furnace and melted to continue the cycle. This approach avoids the important temperature limitations of conventional tube-type heat exchangers, giving rise to the potential of converting heat energy into useful work at considerably higher efficiencies than currently attainable and of storing energy at high thermodynamic potential.

Shaw, D.; Bruckner, A. P.; Hertzberg, A.

1980-01-01

333

Numerical modeling of heat transfer in the fuel oil storage tank at thermal power plant  

NASA Astrophysics Data System (ADS)

Presents results of mathematical modeling of convection of a viscous incompressible fluid in a rectangular cavity with conducting walls of finite thickness in the presence of a local source of heat in the bottom of the field in terms of convective heat exchange with the environment. A mathematical model is formulated in terms of dimensionless variables "stream function - vorticity vector speed - temperature" in the Cartesian coordinate system. As the results show the distributions of hydrodynamic parameters and temperatures using different boundary conditions on the local heat source.

Kuznetsova, Svetlana A.

2015-01-01

334

DNS of turbulent heat transfer in channel flow with low to medium-high Prandtl number fluid  

Microsoft Academic Search

The direct numerical simulation (DNS) of the turbulent heat transfer for various Prandtl numbers ranging from 0.025 to 5 are performed to obtain statistical quantities such as turbulent heat flux, temperature variance and their budget terms. The configuration is the fully developed channel flow with uniform heating from both walls. The Reynolds number based on the friction velocity and the

Hiroshi Kawamura; Kouichi Ohsaka; Hiroyuki Abe; Kiyoshi Yamamoto

1998-01-01

335

Steady Boundary Layer Slip Flow along with Heat and Mass Transfer over a Flat Porous Plate Embedded in a Porous Medium  

PubMed Central

In this paper, a simplified model of an incompressible fluid flow along with heat and mass transfer past a porous flat plate embedded in a Darcy type porous medium is investigated. The velocity, thermal and mass slip conditions are utilized that has not been discussed in the literature before. The similarity transformations are used to transform the governing partial differential equations (PDEs) into a nonlinear ordinary differential equations (ODEs). The resulting system of ODEs is then reduced to a system of first order differential equations which was solved numerically by using Matlab bvp4c code. The effects of permeability, suction/injection parameter, velocity parameter and slip parameter on the structure of velocity, temperature and mass transfer rates are examined with the aid of several graphs. Moreover, observations based on Schmidt number and Soret number are also presented. The result shows, the increase in permeability of the porous medium increase the velocity and decrease the temperature profile. This happens due to a decrease in drag of the fluid flow. In the case of heat transfer, the increase in permeability and slip parameter causes an increase in heat transfer. However for the case of increase in thermal slip parameter there is a decrease in heat transfer. An increase in the mass slip parameter causes a decrease in the concentration field. The suction and injection parameter has similar effect on concentration profile as for the case of velocity profile. PMID:25531301

Aziz, Asim; Siddique, J. I.; Aziz, Taha

2014-01-01

336

Steady boundary layer slip flow along with heat and mass transfer over a flat porous plate embedded in a porous medium.  

PubMed

In this paper, a simplified model of an incompressible fluid flow along with heat and mass transfer past a porous flat plate embedded in a Darcy type porous medium is investigated. The velocity, thermal and mass slip conditions are utilized that has not been discussed in the literature before. The similarity transformations are used to transform the governing partial differential equations (PDEs) into a nonlinear ordinary differential equations (ODEs). The resulting system of ODEs is then reduced to a system of first order differential equations which was solved numerically by using Matlab bvp4c code. The effects of permeability, suction/injection parameter, velocity parameter and slip parameter on the structure of velocity, temperature and mass transfer rates are examined with the aid of several graphs. Moreover, observations based on Schmidt number and Soret number are also presented. The result shows, the increase in permeability of the porous medium increase the velocity and decrease the temperature profile. This happens due to a decrease in drag of the fluid flow. In the case of heat transfer, the increase in permeability and slip parameter causes an increase in heat transfer. However for the case of increase in thermal slip parameter there is a decrease in heat transfer. An increase in the mass slip parameter causes a decrease in the concentration field. The suction and injection parameter has similar effect on concentration profile as for the case of velocity profile. PMID:25531301

Aziz, Asim; Siddique, J I; Aziz, Taha

2014-01-01

337

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

338

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

339

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

E-print Network

the bacterial heat resistance. The estimate of zT (4.64°C) is in the range of values20 given in literature to a ten fold reduction in -value zT quantifies the35 influence of the heating temperature on the bacterial heat resistance.36 zpH : distance of pH from pH* which leads to a ten fold reduction in -value zp

Paris-Sud XI, Université de

340

Dehydrogenation of isopropanol for utilization of waste heat: A chemical heat pump for heat and/or hydrogen storage and transport  

SciTech Connect

The endothermic catalytic dehydrogenation of isopropanol has been studied both experimentally and theoretically. By optimizing the dehydrogenation reaction, a chemical heat pump/temperature amplifier may be developed for upgrading low temperature (approximately 80 C) waste heat to a more usable form (150--200 C) via the exothermic hydrogenation reaction. Methods to reduce the reaction temperature have been proposed and tested. Reaction rates for the evolution of hydrogen were measured and a kinetic model of a falling film reactor has been developed. It has been shown that simulated boiling aids in scrubbing the catalyst surface of acetone. Overall system efficiencies have been presented along with the advantages and disadvantages of the isopropanol/acetone chemical heat pump.

Satyapal, S.; Hall, R.J.; Evans, C.C. [United Technologies Research Center, East Hartford, CT (United States)

1996-12-31

341

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

PubMed Central

ABSTRACT Objective: Postpartum hemorrhage can be reduced substantially in home deliveries attended by community-based workers by using Oxytocin-in-Uniject (OIU) devices affixed with temperature-time indicators. We characterized the distribution of time to discard of these devices when stored under normal field conditions in Ghana. Methods: Two drug storage simulation studies were conducted in rural Ghana in 2011 and 2012. Devices were transported under refrigeration from manufacture (Argentina) to storage at the study site. Twenty-three field workers each stored at home (unrefrigerated) 25 OIU devices and monitored them daily to record: (1) time to transition from usable to unusable, and (2) continuous digital ambient temperature to determine heat exposure over the simulation period. Time to discard was estimated and compared with mean kinetic temperature exposure of the devices during the shipment and storage phases and with characteristics of the storage locations using Weibull regression models. We used the time to discard distributions in a Monte Carlo simulation to estimate wastage rates in a hypothetical program setting. Results: Time for shipment and transfer to long-term refrigerated storage and mean kinetic temperature during the shipment phase was 8.6 days/10.3°C and 13.4 days/12.1°C, for the first and second simulation studies, respectively. Median (range) time to discard when stored under field conditions (unrefrigerated) was 43 (6 to 59) days and 33 (14 to 50) days, respectively. Mean time to discard was 10.0 days shorter in the second simulation, during which mean kinetic temperature exposure was 3.9°C higher. Simulating a monthly distribution system and assuming typical usage, predicted wastage of product was less than 10%. Conclusion: The time to discard of devices was highly sensitive to small changes in temperature exposure. Under field conditions typical in rural Ghana, OIU packages will have a half-life of approximately 30 to 40 days based on the temperature monitor used during the study. Program managers will need to carefully consider variations in both ambient temperature and rate of use to allocate the appropriate supply level that will maximize coverage and minimize stock loss. PMID:25276588

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

2014-01-01

342

Analysis of combined conductive-radiative heat transfer in a two-dimensional rectangular enclosure with a gray medium  

Microsoft Academic Search

Combined conductive-radiative heat transfer in a two-dimensional enclosure is considered. The numerical procedure is based on a combination of two previous techniques that have been demonstrated to be successful for a two-dimensional pure radiation problem and a one-dimensional combined conductive-radiative heat transfer problem, respectively. Both temperature profile and heat transfer distributions are generated efficiently and accurately. Numerical data are presented

W. W. Yuen; E. E. Takara

1988-01-01

343

Thermal performance of submerged coil heat exchangers used in solar energy storage tanks  

Microsoft Academic Search

It can be seen from the test results that for the coil flow rate range of interest in solar DHW systems submersed coil heat exchangers can have effectiveness values as low as 0.3 for double-wall coils. This translates into a penalty of 12 to 15 percent for system performance. Inlet and outlet temperatures for the coil are easily measured. The

D. E. Klett; D. Y. Goswami; M. T. Suad

1984-01-01

344

Experimental evaluation of commercial heat exchangers for use as PCM thermal storage systems  

Microsoft Academic Search

Phase change materials (PCM) possess a great capacity of accumulation of energy in their temperature of fusion thanks to the latent heat. These materials are used in applications where it is necessary to store energy due to the temporary phase shift between the offer and demand of thermal energy. Thus, possible applications are the solar systems as well as the

M. Medrano; M. O. Yilmaz; M. Nogués; I. Martorell; Joan Roca; Luisa F. Cabeza

2009-01-01

345

Design of a phase change shell and tube heat exchanger for thermal energy storage  

Microsoft Academic Search

In this paper, design analysis of a shell and tube heat exchanger with a phase change material on the shell side cooled by a fluid passing through the tube is presented. A simple closed form design for two-dimensional freezing is presented. Results from the present analysis are shown to agree within two per cent of the involved numerical solutions to

S. Saxena; M. K. Sarkar; S. Subrahmaniyam

1983-01-01

346

The rate of heat storage mediates an anticipatory reduction in exercise intensity during cycling at a fixed rating of perceived exertion.  

PubMed

The aim of the present study was to examine the regulation of exercise intensity in hot environments when exercise is performed at a predetermined, fixed subjective rating of perceived exertion (RPE). Eight cyclists performed cycling trials at 15 degrees C (COOL), 25 degrees C (NORM) and 35 degrees C (HOT) (65% humidity throughout), during which they were instructed to cycle at a Borg rating of perceived exertion (RPE) of 16, increasing or decreasing their power output in order to maintain this RPE. Power output declined linearly in all three trials and the rate of decline was significantly higher in HOT than in NORM and COOL (2.35 +/- 0.73 W min(-1), 1.63 +/- 0.70 and 1.61 +/- 0.80 W min(-1), respectively, P < 0.05). The rate of heat storage was significantly higher in HOT for the first 4 min of the trials only, as a result of increasing skin temperatures. Thereafter, no differences in heat storage were found between conditions. We conclude that the regulation of exercise intensity is controlled by an initial afferent feedback regarding the rate of heat storage, which is used to regulate exercise intensity and hence the rate of heat storage for the remainder of the anticipated exercise bout. This regulation maintains thermal homeostasis by reducing the exercise work rate and utilizing the subjective RPE specifically to ensure that excessive heat accumulation does not occur and cellular catastrophe is avoided. PMID:16497719

Tucker, Ross; Marle, Trevor; Lambert, Estelle V; Noakes, Timothy D

2006-08-01

347

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

SciTech Connect

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

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

1998-03-01

348

Two-dimensional transient thermal analysis of PCM canister of a heat pipe receiver under microgravity  

Microsoft Academic Search

High temperature phase change material (PCM) is used as a thermal storage medium of a heat pipe receiver in an advanced solar dynamic system. With both void cavity and phase change considered, thermal performance of the heat pipe receiver was numerically analyzed under microgravity. The results indicate that the PCM contained in the integrated heat pipe performs the averaging function

Gui Xiaohong; Lin Bin; Guo Yongxian; Yuan Xiugan

2011-01-01

349

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

PubMed Central

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

2013-01-01

350

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

PubMed

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

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

2013-01-01

351

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

352

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

NASA Technical Reports Server (NTRS)

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

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

1988-01-01

353

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

NASA Technical Reports Server (NTRS)

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

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

1988-01-01

354

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

355

Comparison between two common collocation approaches based on radial basis functions for the case of heat transfer equations arising in porous medium  

E-print Network

In this paper two common collocation approaches based on radial basis functions have been considered; one be computed through the integration process (IRBF) and one be computed through the differentiation process (DRBF). We investigated the two approaches on natural convection heat transfer equations embedded in porous medium which are of great importance in the design of canisters for nuclear wastes disposal. Numerical results show that the IRBF be performed much better than the common DRBF, and show good accuracy and high rate of convergence of IRBF process.

K. Parand; S. Abbasbandy; S. Kazem; A. R. Rezaei

2010-08-16

356

Comparison between two common collocation approaches based on radial basis functions for the case of heat transfer equations arising in porous medium  

E-print Network

In this paper two common collocation approaches based on radial basis functions have been considered; one be computed through the integration process (IRBF) and one be computed through the differentiation process (DRBF). We investigated the two approaches on natural convection heat transfer equations embedded in porous medium which are of great importance in the design of canisters for nuclear wastes disposal. Numerical results show that the IRBF be performed much better than the common DRBF, and show good accuracy and high rate of convergence of IRBF process.

Parand, K; Kazem, S; Rezaei, A R; 10.1016/j.cnsns.2010.07.011

2010-01-01

357

Comparison between two common collocation approaches based on radial basis functions for the case of heat transfer equations arising in porous medium  

NASA Astrophysics Data System (ADS)

In this paper two common collocation approaches based on radial basis functions have been considered; one be computed through the integration process (IRBF) and one be computed through the differentiation process (DRBF). We investigated the two approaches on natural convection heat transfer equations embedded in porous medium which are of great importance in the design of canisters for nuclear wastes disposal. Numerical results show that the IRBF be performed much better than the common DRBF, and show good accuracy and high rate of convergence of IRBF process.

Parand, K.; Abbasbandy, S.; Kazem, S.; Rezaei, A. R.

2011-03-01

358

Antimicrobial activity of plant compounds against Salmonella Typhimurium DT104 in ground pork and the influence of heat and storage on the activity  

Technology Transfer Automated Retrieval System (TEKTRAN)

The objectives of this study were to investigate the influence of heat (70oC for 5 min) and cold-storage (4oC up to 7 days) on the effectiveness of oregano and cinnamon essential oils and powdered olive and apple extracts against Salmonella Typhimurium DT104 in ground pork and to evaluate the activi...

359

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

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

360

An inverse analysis to estimate linearly temperature dependent thermal conductivity components and heat capacity of an orthotropic medium  

Microsoft Academic Search

An inverse analysis is used to estimate linearly temperature dependent thermal conductivity components kx(T), ky(T) and specific heat capacity C(T) per unit volume for an orthotropic solid. Simulated measured transient temperature data are generated by adding random errors to the exact temperatures computed from the solution of the two-dimensional, direct transient heat conduction problem. An iterative procedure, based on minimizing

Y. Jarny

1995-01-01

361

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

362

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

NASA Astrophysics Data System (ADS)

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

Hegazy, Ahmed Sabry

363

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

364

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

NASA Astrophysics Data System (ADS)

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

Kothandapani, M.; Srinivas, S.

2008-06-01

365

A solar energy system as a complement to a conventional heating system: Measurement of the storage and consumption of solar energy  

NASA Astrophysics Data System (ADS)

A residential house, having a fuel oil based heating system (radiators and floor heating; domestic hot water), was equipped with a solar energy conversion plant which supplemented the water heating system. Total insolation, the energy received by the solar collectors, and energy consumption for heating and domestic hot water were monitored. Results show the collector system to have a conversion efficiency of 15.4%. The solar energy system contribution to overall energy consumption was 6.1%. Improvement of the solar energy plant is discussed. Suggestions include enlarging the collector surface, alteration of the regulation scheme, utilization of thermal stratification in the conception of solar heat storage, better insulation of conduit pipes, and avoidance of shadowing the collectors.

Doering, E.; Lippe, W.

1980-09-01

366

SERI Solar Energy Storage Program: FY 1984  

NASA Astrophysics Data System (ADS)

The activities of the Solar Energy Research Institute's Solar Energy Research Institute's Solar Energy Storage Program during its sixth year are summarized. During FY 1984 a study was conducted to identify the most promising high-temperature containment concepts considering corrosion resistance, material strength at high temperature, reliability of performance, and cost. Of the two generic types of high-temperature thermal storage concepts, the single-tank system was selected using a two-medium approach to the thermocline maintenance. This concept promises low costs, but further research is required. A conceptual design for a sand-to-air direct-contact heat exchanger was developed using dual-lock hoppers to introduce the sand into the fluidized-bed exchanger, and using cyclones to remove sand particles from the output air stream. Preliminary cost estimates indicate heat exchanger subsystem annual levelized costs of about $4/GJ with compressor costs of an additional $0.75/GJ. An economic analysis comparing sensible and latent heat storage for nitrate and carbonate salts with solely sensible heat storage showed 3%-21% cost savings with combined sensible and latent heat storage.

Luft, W.; Bohn, M.; Copeland, R. J.; Kreith, F.; Nix, R. G.

1985-02-01

367

Start-Up Characteristics and Gravity Effects on a Medium\\/High-Lift Heat Pump using Advanced Hybrid Loop Technology  

Microsoft Academic Search

Thermal characterization was performed on a vapor compression heat pump using a novel, hybrid two phase loop design. Previous work on this technology has demonstrated its ability to provide passive phase separation and flow control based on capillary action. This provides high quality vapor to the compressor without relying on gravity-based phase separation or other active devices. This paper describes

Eric Sunada; Jennifer Miller; Gani B. Ganapathi; Gajanana Birur; Chanwoo Park

368

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

369

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

PubMed

Alicyclobacillus acidoterrestris is a spoilage bacterium in fruit juices leading to high economic losses. The present study evaluated the effect of sporulation medium on the thermal inactivation kinetics of A. acidoterrestris DSM 3922 spores in apple juice (pH3.82±0.01; 11.3±0.1 °Brix). Bacillus acidocaldarius agar (BAA), Bacillus acidoterrestris agar (BATA), malt extract agar (MEA), potato dextrose agar (PDA) and B. acidoterrestris broth (BATB) were used for sporulation. Inactivation kinetic parameters at 85, 87.5 and 90°C were obtained using the log-linear model. The decimal reduction times at 85°C (D85°C) were 41.7, 57.6, 76.8, 76.8 and 67.2min; D87.5°C-values were 22.4, 26.7, 32.9, 31.5, and 32.9min; and D90°C-values were 11.6, 9.9, 14.7, 11.9 and 14.1min for spores produced on PDA, MEA, BATA, BAA and BATB, respectively. The estimated z-values were 9.05, 6.60, 6.96, 6.15, and 7.46, respectively. The present study suggests that the sporulation medium affects the wet-heat resistance of A. acidoterrestris DSM 3922 spores. Also, the dipicolinic acid content (DPA) was found highest in heat resistant spores formed on mineral containing media. After wet-heat treatment, loss of internal volume due to the release of DPA from spore core was observed by scanning electron microscopy. Since, there is no standardized media for the sporulation of A. acidoterrestris, the results obtained from this study might be useful to determine and compare the thermal resistance characteristics of A. acidoterrestris spores in fruit juices. PMID:25129530

Molva, Celenk; Baysal, Ayse Handan

2014-10-17

370

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

E-print Network

Based on an experimental residential retrofit incorporating thermal storage, and extensive subsequent modeling, a commercial design was developed and implemented to use hot thermal storage to significantly reduce electric demand and utility energy...

Meckler, G.

1985-01-01

371

H2O heating in molecular clouds - Line transfer and thermal balance in a warm dusty medium  

NASA Technical Reports Server (NTRS)

An investigation is undertaken into the possibility of the heating of molecular gas through collisions with radiatively pumped H2O, in the context of the overall thermal balance of optically thick molecular clouds with embedded sources. In order to solve the line transfer equation, which includes warm dust grains, an extended method of escape probability approximation is developed in which the equilibrium gas temperature arises from the balance of heating by cosmic ray ionization of H2, and by collisions with warm dust grains and radiatively pumped H2O molecules against cooling by collisions with CO and C I. The equilibrium gas temperature for a given dust temperature strongly depends on the efficiency of the cooling species, and is therefore most sensitive to the cloud optical depth. It is less dependent, in decreasing order, on H2O abundance, gas density, and velocity dispersion.

Takahashi, T.; Silk, J.; Hollenbach, D. J.

1983-01-01

372

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

373

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

NASA Astrophysics Data System (ADS)

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

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

2014-07-01

374

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

375

Investigation of heat and mass transfer process in metal hydride hydrogen storage reactors, suitable for a solar powered water pump system  

NASA Astrophysics Data System (ADS)

The paper analyzes heat and mass transfer process in metal hydride hydrogen storage systems as key element in the development of a solar powered pump system. Hydrogen storage and compression performance of the developed reactors are investigated according to the type of metal alloys, the metal hydride bed parameters and system operating conditions. To reach the desired goal, some metal hydride from groups AB5 and AB2 were synthesized and characterized using elements substitution for tailoring their properties: reversible hydrogen absorption capacity between the hydrogen absorption and desorption pressures at equilibrium at small temperature differences. For the designed hydrogen storage reactors, a new technical solution which combines the effective increase of the thermal conductivity of MH bed and good permeability to hydrogen gas circulation, was implemented and tested. The results permitted us to develop a heat engine with metal hydride, the main element of the functional model of a heat operated metal hydride based water pumping system using solar energy. This is a free energy system able to deliver water, at a convenience flow and pressure, in remote places without conventional energy access.

Coldea, I.; Popeneciu, G.; Lupu, D.; Misan, I.; Blanita, G.; Ardelean, O.

2012-02-01

376

Extended development of a sodium hydroxide thermal-energy storage module  

SciTech Connect

Development of a phase-change thermal storage system (TESS) using modified anhydrous sodium hydroxide and a single, passive, tube-intensive heat exchanger, for charging and discharging heat at approximately 584 K by a non-phase-change heat transfer liquid, Therminol-66 continued. The three parts of the present program were (1) chemical analyses on the storage medium and examination of its heat exchanger, (2) production of additional experimental data using a different non-phase change heat transfer fluid (Caloria HT-43) to extend the validation of a computer model of the TESS, and (3) development of a new computer model of a TESS containing an additional heat exchanger for the vaporization and superheating of a power fluid for a Rankine cycle power generator, and the use of the model to develop a cost optimized reference TESS design for comparison with the single heat exchanger TESS design. From the prior experimental work it was concluded that no chemical degradation of the medium occurred, but some physical segregation of components, which can be reversed by fully remelting the medium, was observed. No significant deterioration of the heat exchanger was found. A computer model was successfully developed which provides for 3-way heat transfer, between each fluid and the medium, and directly between the two fluids. The reference design of the 2-heat exchanger TESS improved thermal performance, capital cost, and overall system operating cost.

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

1980-09-01

377

Heating system with focused solar panels and heat pump assist  

Microsoft Academic Search

A heating system for a building having solar panels for collecting solar heat including sunlight concentrating lenses and a heat storage chamber for storing excess solar heat is disclosed. A heat pump is provided to supplement the solar heat when the temperature in the heat storage chamber is below a comfortable level. During heat pump operation, solar warmed air is

Franchina

1981-01-01

378

Solar-powered saline sorbent-solution heat pump\\/storage system. [Coastal Energy Laboratory-Chemical Heat Pump (CEL-CHEAP)  

Microsoft Academic Search

Coastal Energy Laboratory Chemical Heat Pump (CEL-CHEAP) is a redesigned open-cycle liquid desiccant air conditioner. Heat is discharged to shallow-well water by dehumidification-humidification for cooling and extracted by humidification-dehumidification for heating. Direct solar radiation concentrates the desiccant. For continuous operation, a small uninsulated tank stores concentrated solution. 6 refs.

H. Robison; S. Houston

1981-01-01

379

Thermal storage for electric utilities  

NASA Technical Reports Server (NTRS)

Applications of the thermal energy storage (TES) principle (storage of sensible heat or latent heat, or heat storage in reversible chemical reactions) in power systems are evaluated. Load leveling behind the meter, load following at conventional thermal power plants, solar thermal power generation, and waste heat utilization are the principal TES applications considered. Specific TES examples discussed include: storage heaters for electric-resistance space heating, air conditioning TES in the form of chilled water or eutectic salt baths, hot water TES, and trans-seasonal storage in heated water in confined aquifers.

Swet, C. J.; Masica, W. J.

1977-01-01

380

Large-scale jets from active galactic nuclei as a source of intracluster medium heating: cavities and shocks  

NASA Astrophysics Data System (ADS)

The evolution of powerful extragalactic jets is not only interesting by itself, but also for its impact on the evolution of the host galaxy and its surroundings. We have performed long-term axisymmetric numerical simulations of relativistic jets with different powers to study their evolution through an environment with a pressure and density gradient. Our results show key differences in the evolution of jets with different powers in terms of the spatial and temporal scales of energy deposition. According to our results, the observed morphology in X-ray cavities requires that an important fraction of the jet's energetic budget is in the form of internal energy. Thus, light, lepton-dominated jets are favoured. In all cases, heating is mainly produced by shocks. Cavity overpressure is sustained by an important population of thermal particles. Our simulations reproduce the cool-core structure in projected, luminosity-weighted temperature. We have performed an additional simulation of a slow, massive jet and discuss the differences with its relativistic counterparts. Important qualitative and quantitative differences are found between the non-relativistic and the relativistic jets. Our conclusions point towards a dual mode of active galactic nuclei kinetic feedback, depending on the jet power.

Perucho, Manel; Martí, José-María; Quilis, Vicent; Ricciardelli, Elena

2014-12-01

381

Numerical Analysis for Characteristics of Ice Fomation and Mlting for Latent Heat Thermal Energy Storage Cell Using Resin Tube-Mat  

NASA Astrophysics Data System (ADS)

Characteristics of ice formation and melting for latent heat thermal energy storage cell using resin tube-mat to prevent destruction by a volume increase of ice and corrosion of heat exchanger tube was examined by the numerical analysis. The numerical analysis is carried out with the enthalpy method does not need the special handling by the introducing latent heat term. The numerical results agree well with the experimental results. Influence on ice formation and melting was considered by the difference between the size (thickness of tube and diameter, etc.) and the physical properties of resin tube. Quantity of ice formation and melting is almost proportion at time. Thickness of tube greatly influences ice formation and melting. Ice formation and melting quicken as the thickness of tube thins. Ice formation speed increases as the inner diameter of tube grows. However, increase proportion at formation or melting speed becomes small as the inner diameter of tube grows. As a result, a basic characteristic of latent heat thermal energy storage cell using resin tube-mat was clarified.

Hirasawa, Yoshio; Kitano, Kazuyuki; Kosaka, Akio

382

Summary Report for Concentrating Solar Power Thermal Storage Workshop: New Concepts and Materials for Thermal Energy Storage and Heat-Transfer Fluids, May 20, 2011  

SciTech Connect

This document summarizes a workshop on thermal energy storage for concentrating solar power (CSP) that was held in Golden, Colorado, on May 20, 2011. The event was hosted by the U.S. Department of Energy (DOE), the National Renewable Energy Laboratory, and Sandia National Laboratories. The objective was to engage the university and laboratory research communities to identify and define research directions for developing new high-temperature materials and systems that advance thermal energy storage for CSP technologies. This workshop was motivated, in part, by the DOE SunShot Initiative, which sets a very aggressive cost goal for CSP technologies -- a levelized cost of energy of 6 cents per kilowatt-hour by 2020 with no incentives or credits.

Glatzmaier, G.

2011-08-01

383

Experimental Investigation of the Properties of Lime-Based Plaster-Containing PCM for Enhancing the Heat-Storage Capacity of Building Envelopes  

NASA Astrophysics Data System (ADS)

Experimental analysis of a wide range of properties of a lightweight plaster which should enhance the heat-storage capacity of building envelopes is presented. The basic physical characteristics, namely, the bulk density, matrix density, total open porosity, and pore-size distribution are measured at first. Then, the compressive strength is determined for an assessment of mechanical performance of the plaster. The thermal conductivity and thermal diffusivity are studied using an impulse technique. Differential scanning calorimetry measurements are performed as well, in order to identify the temperature range and latent heat of the phase change and to determine the specific heat capacity as a function of temperature. Durability properties are assessed using the measurement of the water absorption coefficient and sorption and desorption isotherms. The experimental results indicate a good capability of the designed plaster to moderate effectively the interior climate of buildings.

Pavlík, Zbyšek; Trník, Anton; Keppert, Martin; Pavlíková, Milena; Žumár, Jaromír; ?erný, Robert

2014-04-01

384

Antimicrobial activity of plant compounds against Salmonella Typhimurium DT104 in ground pork and the influence of heat and storage on the antimicrobial activity.  

PubMed

Salmonella enterica is a predominant foodborne pathogen that causes diarrheal illness worldwide. A potential method of inhibiting pathogenic bacterial growth in meat is through the introduction of plant-derived antimicrobials. The objectives of this study were to investigate the influence of heat (70°C for 5 min) and subsequent cold storage (4°C up to 7 days) on the effectiveness of oregano and cinnamon essential oils and powdered olive and apple extracts against Salmonella enterica serovar Typhimurium DT104 in ground pork and to evaluate the activity of the most effective antimicrobials (cinnamon oil and olive extract) at higher concentrations in heated ground pork. The surviving Salmonella populations in two groups (heated and unheated) of antimicrobial-treated pork were compared. Higher concentrations of the most effective compounds were then tested (cinnamon oil at 0.5 to 1.0% and olive extract at 3, 4, and 5%) against Salmonella Typhimurium in heated ground pork. Samples were stored at 4°C and taken on days 0, 3, 5, and 7 for enumeration of survivors. The heating process did not affect the activity of antimicrobials. Significant 1.3- and 3-log reductions were observed with 1.0% cinnamon oil and 5% olive extract, respectively, on day 7. The minimum concentration required to achieve . 1-log reduction in Salmonella population was 0.8% cinnamon oil or 4% olive extract. The results demonstrate the effectiveness of these antimicrobials against multidrug-resistant Salmonella Typhimurium in ground pork and their stability during heating and cold storage. The most active formulations have the potential to enhance the microbial safety of ground pork. PMID:23834804

Chen, Cynthia H; Ravishankar, Sadhana; Marchello, John; Friedman, Mendel

2013-07-01

385

Effect of medium and temperature of storage on viability of lactic acid bacteria immobilized in ?-carrageenan-locust bean gum gel beads  

Microsoft Academic Search

Summary  The influence of various storage solutions and temperature (4C and 25C) on viability ofStreptococcus salivarius subsp.thermophilus andLactobacillusdelbrueckii subsp.bulgaricus entrapped in ?-carrageenan-locust bean gum mixed gel beads was studied. The immobilized strains could be stored at 4C in\\u000a all storage solutions studied for at least 14 and 11 days respectively before counts decreased to 105c.f.u.\\/mL, which was considered to be the

Pascal Audet; Céline Paquin; Christophe Lacroix

1991-01-01

386

User manual for AQUASTOR: a computer model for cost analysis of aquifer thermal energy storage coupled with district heating or cooling systems. Volume I. Main text  

SciTech Connect

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 stored hot water or ATES district cooling systems using stored chilled water. AQUASTOR simulates the complete ATES district heating (cooling) system, which consists of two principal parts: the ATES supply system and the district heating (cooling) distribution system. The supply system submodel calculates the life-cycle cost of thermal energy supplied to the distribution system by simulating the technical design and cash flows for the exploration, development, and operation of the ATES supply system. The distribution system submodel calculates the life-cycle cost of heat (chill) delivered by the distribution system to the end-users by simulating the technical design and cash flows for the construction and operation of the distribution system. The model combines the technical characteristics of the supply system and the technical characteristics of the distribution system with financial and tax conditions for the entities operating the two systems into one techno-economic model. This provides the flexibility to individually or collectively evaluate the impact of different economic and technical parameters, assumptions, and uncertainties on the cost of providing district heating (cooling) with an ATES system. This volume contains the main text, including introduction, program description, input data instruction, a description of the output, and Appendix H, which contains the indices for supply input parameters, distribution input parameters, and AQUASTOR subroutines.

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

1982-04-01

387

Study of an electrical heating system with ductless air supply and shape-stabilized PCM for thermal storage  

Microsoft Academic Search

A kind of electrical floor heating system with a shape-stabilized phase change material (PCM) which has been studied at Tsinghua University in our previous studies, can provide space heating during the whole day and can be controlled conventionally. However, this is not suitable for office buildings where no space heating is needed at night. The effective control is very important

Kunping Lin; Yinping Zhang; Hongfa Di; Rui Yang

2007-01-01

388

Development of a phase-change thermal storage system using modified anhydrous sodium hydroxide for solar electric power generation  

NASA Technical Reports Server (NTRS)

A thermal storage system for use in solar power electricity generation was investigated analytically and experimentally. The thermal storage medium is principally anhydrous NaOH with 8% NaNO3 and 0.2% MnO2. Heat is charged into storage at 584 K and discharged from storage at 582 K by Therminol-66. Physical and thermophysical properties of the storage medium were measured. A mathematical simulation and computer program describing the operation of the system were developed. A 1/10 scale model of a system capable of storing and delivering 3.1 x 10 to the 6th power kJ of heat was designed, built, and tested. Tests included steady state charging, discharging, idling, and charge-discharge conditions simulating a solar daily cycle. Experimental data and computer-predicted results are correlated. A reference design including cost estimates of the full-size system was developed.

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

1978-01-01

389

Corrosive resistant heat exchanger  

DOEpatents

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

Richlen, Scott L. (Annandale, VA)

1989-01-01

390

Mixed convection magnetohydrodynamic heat and mass transfer past a stretching surface in a micropolar fluid-saturated porous medium under the influence of Ohmic heating, Soret and Dufour effects  

NASA Astrophysics Data System (ADS)

A numerical model is developed to examine the combined effects of Soret and Dufour on mixed convection magnetohydrodynamic heat and mass transfer in micropolar fluid-saturated Darcian porous medium in the presence of thermal radiation, non-uniform heat source/sink and Ohmic dissipation. The governing boundary layer equations for momentum, angular momentum (microrotation), energy and species transfer are transformed to a set of non-linear ordinary differential equations by using similarity solutions which are then solved numerically based on shooting algorithm with Runge-Kutta-Fehlberg integration scheme over the entire range of physical parameters with appropriate boundary conditions. The influence of Darcy number, Prandtl number, Schmidt number, Soret number and Dufour number, magnetic parameter, local thermal Grashof number and local solutal Grashof number on velocity, temperature and concentration fields are studied graphically. Finally, the effects of related physical parameters on local Skin-friction, local Nusselt number and local Sherwood number are also studied. Results showed that the fields were influenced appreciably by the Soret and Dufour effects, thermal radiation and magnetic field, etc.

Pal, Dulal; Chatterjee, Sewli

2011-03-01

391

Systems and methods for facilitating hydrogen storage using naturally occurring nanostructure assemblies  

DOEpatents

Some or all of the needs above can be addressed by embodiments of the invention. According to embodiments of the invention, systems and methods for facilitating hydrogen storage using naturally occurring nanostructure assemblies can be implemented. In one embodiment, a method for storing hydrogen can be provided. The method can include providing diatoms comprising diatomaceous earth or diatoms from a predefined culture. In addition, the method can include heating the diatoms in a sealed environment in the presence of at least one of titanium, a transition metal, or a noble metal to provide a porous hydrogen storage medium. Furthermore, the method can include exposing the porous hydrogen storage medium to hydrogen. In addition, the method can include storing at least a portion of the hydrogen in the porous hydrogen storage medium.

Fliermans; , Carl B. (Augusta, GA)

2012-08-07

392

Measurements of heating and energy storage in flashlamp-pumped Nd: YAg and Nd-doped phosphate laser glasses  

Microsoft Academic Search

The authors have experimentally measured the energy stored aNd the heat generated in flashlamp-pumped Nd:YAg and six different commercially available Nd-doped phosphate glasses. They find that the normalized heating parameter, defined as the heat deposited per unit stored energy, is 1.5-2 times the value expected from the known spectroscopy of the Nd ions in these hosts and the emission spectrum

M. Mangir; D. A. Rockwell

1986-01-01

393

Thermal energy storage  

NASA Technical Reports Server (NTRS)

The planning and implementation of activities associated with lead center management role and the technical accomplishments pertaining to high temperature thermal energy storage subsystems are described. Major elements reported are: (1) program definition and assessment; (2) research and technology development; (3) industrial storage applications; (4) solar thermal power storage applications; and (5) building heating and cooling applications.

1980-01-01

394

Glass heat pipe evacuated tube solar collector  

SciTech Connect

A glass heat pipe is adapted for use as a solar energy absorber in an evacuated tube solar collector and for transferring the absorbed solar energy to a working fluid medium or heat sink for storage or practical use. A capillary wick is formed of granular glass particles fused together by heat on the inside surface of the heat pipe with a water glass binder solution to enhance capillary drive distribution of the thermal transfer fluid in the heat pipe throughout the entire inside surface of the evaporator portion of the heat pipe. Selective coatings are used on the heat pipe surface to maximize solar absorption and minimize energy radiation, and the glass wick can alternatively be fabricated with granular particles of black glass or obsidian.

McConnell, R.D.; Vansant, J.H.

1984-10-02

395

Environmental microbiology as related to planetary quarantine. [synergetic effect of heat and radiation  

NASA Technical Reports Server (NTRS)

The mechanistic basis of the synergetic effect of combined heat and radiation on microbial destruction was analyzed and results show that radiation intensity, temperature, and relative humidity are the determining factors. Dry heat resistance evaluation for selected bacterial spore crops indicates that different strains of Bacillus stearothermophilus demonstrate marked differences in resistance. Preliminary work to determine the effects of storage time, suspending medium, storage temperature and spore crop cleaning procedures on dry heat survival characteristics of Bacillus subtilis var. Niger, and dry heat resistance of natural microflora in soil particles is also reported.

Pflug, I. J.

1973-01-01

396

Storage systems for solar thermal power  

NASA Technical Reports Server (NTRS)

The development status is reviewed of some thermal energy storage technologies specifically oriented towards providing diurnal heat storage for solar central power systems and solar total energy systems. These technologies include sensible heat storage in caverns and latent heat storage using both active and passive heat exchange processes. In addition, selected thermal storage concepts which appear promising to a variety of advanced solar thermal system applications are discussed.

Calogeras, J. E.; Gordon, L. H.

1978-01-01

397

Effects of NaCl, sucrose, and storage on rheological parameters of heat induced gels of liquid egg products  

E-print Network

-30 minutes 55 12 Gel strength of egg yolk stored at -10 C (24 hrs. ) then heated at 80 C for 0-30 minutes 57 Figure 13 14 15 Elasticity of egg yolk stored at 24oC (6 hrs. ) then heated at 80 C for 0-30 minutes Elasticity of egg yolk stored at 3 C (18... of liquid egg products utilized fresh, refrigerated or frozen. A counter-flow back extrusion method was used to measure the rheological parameters of gel strength, elasticity, and viscosity of heat induced gels of albumen, yolk, and blended whole egg...

Brough, Joan

1988-01-01

398

Investigating the effect of bottom boundary condition placement on ground heat storage in climate time scale simulations using ParflowE  

NASA Astrophysics Data System (ADS)

Heat and water fluxes are key variables affecting the atmosphere-land surface interactions as well as transpiration by plants and geochemical cycles. At climate timescales, the subsurface thermal regime may impact the land surface energy balance via the ground heat flux and associated temperature feedbacks. As a matter of fact, since there is no real lower energy boundary condition, except the natural geothermal heat flux, the subsurface may act as an infinite heat sink in case of a positive temperature trend at the surface. However, due to computational reasons, climate models incorporate a shallow subsurface domain, and thus a shallow temperature boundary condition, which generally is of the Neumann type. This leads to a cumulative ground heat flux of zero over large time scales, which is not realistic, in case of a trend in air temperature. Additionally, the convection term of heat transfer in the subsurface and the memory effect of soil moisture on energy transport is also neglected in climate models by simplified parameterizations. Single soil column model experiments were performed with ParflowE as a subsurface model, which incorporates the more complete heat equation coupled to variably saturated flow, to study the effect of bottom boundary condition placement on ground heat storage and propagated temperature signals over large time-scale with respect to the hydro dynamic process and energy balances. Simulations were carried out over one hundred years (2002-2101) using 4 simple soil columns with the same soil characteristic, lateral boundary conditions and atmosphere forcing, but differing in depth (12, 24, 75 and 150m). After a spin-up period, the models were forced with step-change air temperature and GCM model results namely the IPCC RCP 8.5 scenarios, in order to identify the climate change signals in the subsurface and the associated feedbacks at the land surface. While in the deep soil column, temperature profiles show a heat distribution which is mostly unaffected by the lower boundary condition, the shallow exhibits considerably larger temperatures in the in the shallow soil layers. Thus, over the 100 years, more than 0.45oC soil temperature difference at 12m depth was observed between the shallowest and deepest column simulations In contrast, the about three times more energy was stored in the 150m deep column in comparison to the 12m deep column.

Khorsandi, Ehsan; Kollet, Stefan; Venema, Victor; Simmer, Clemens

2014-05-01

399

New Limits on 21 cm Epoch of Reionization from PAPER-32 Consistent with an X-Ray Heated Intergalactic Medium at z = 7.7  

NASA Astrophysics Data System (ADS)

We present new constraints on the 21 cm Epoch of Reionization (EoR) power spectrum derived from three months of observing with a 32 antenna, dual-polarization deployment of the Donald C. Backer Precision Array for Probing the Epoch of Reionization in South Africa. In this paper, we demonstrate the efficacy of the delay-spectrum approach to avoiding foregrounds, achieving over eight orders of magnitude of foreground suppression (in mK2). Combining this approach with a procedure for removing off-diagonal covariances arising from instrumental systematics, we achieve a best 2? upper limit of (41 mK)2 for k = 0.27 h Mpc-1 at z = 7.7. This limit falls within an order of magnitude of the brighter predictions of the expected 21 cm EoR signal level. Using the upper limits set by these measurements, we generate new constraints on the brightness temperature of 21 cm emission in neutral regions for various reionization models. We show that for several ionization scenarios, our measurements are inconsistent with cold reionization. That is, heating of the neutral intergalactic medium (IGM) is necessary to remain consistent with the constraints we report. Hence, we have suggestive evidence that by z = 7.7, the H I has been warmed from its cold primordial state, probably by X-rays from high-mass X-ray binaries or miniquasars. The strength of this evidence depends on the ionization state of the IGM, which we are not yet able to constrain. This result is consistent with standard predictions for how reionization might have proceeded.

Parsons, Aaron R.; Liu, Adrian; Aguirre, James E.; Ali, Zaki S.; Bradley, Richard F.; Carilli, Chris L.; DeBoer, David R.; Dexter, Matthew R.; Gugliucci, Nicole E.; Jacobs, Daniel C.; Klima, Pat; MacMahon, David H. E.; Manley, Jason R.; Moore, David F.; Pober, Jonathan C.; Stefan, Irina I.; Walbrugh, William P.

2014-06-01

400

Thermal energy storage and regeneration  

Microsoft Academic Search

The newest techniques and theories covering the design and management of thermal energy storage systems in the areas of heat recovery and in circumstances where energy availability does not coincide chronologically with demand are presented. Techniques that predict the performance of sensible heat storage units in a broad range of operating conditions and methods for designing energy storage units for

F. W. Schmidt; A. John Willmott; Frank Kreith

1981-01-01

401

Solar heating and hot water system installed at Arlington Raquetball Club, Arlington, Virginia  

NASA Technical Reports Server (NTRS)

A solar space and water heating system is described. The solar energy system consists of 2,520 sq. ft. of flat plate solar collectors and a 4,000 gallon solar storage tank. The transfer medium in the forced closed loop is a nontoxic antifreeze solution (50 percent water, 50 percent propylene glycol). The service hot water system consists of a preheat coil (60 ft. of 1 1/4 in copper tubing) located in the upper third of the solar storage tank and a recirculation loop between the preheat coil and the existing electric water heaters. The space heating system consists of two separate water to air heat exchangers located in the ducts of the existing space heating/cooling systems. The heating water is supplied from the solar storage tank. Extracts from site files, specification references for solar modifications to existing building heating and hot water systems, and installation, operation and maintenance instructions are included.

1981-01-01

402

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

SciTech Connect

It has been suggested that enhanced geothermal systems (EGS) may be operated with supercritical CO{sub 2} 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{sub 2}, a greenhouse gas. At geothermal temperature and pressure conditions of interest, the flow and heat transfer behavior of CO{sub 2} would be considerably different from water, and chemical interactions between CO{sub 2} and reservoir rocks would also be quite different from aqueous fluids. This paper summarizes our research to date into fluid flow and heat transfer aspects of operating EGS with CO{sub 2}. (Chemical aspects of EGS with CO{sub 2} are discussed in a companion paper; Xu and Pruess, 2010.) Our modeling studies indicate that CO{sub 2} would achieve heat extraction at larger rates than aqueous fluids. The development of an EGS-CO{sub 2} reservoir would require replacement of the pore water by CO{sub 2} through persistent injection. We find that in a fractured reservoir, CO{sub 2} breakthrough at production wells would occur rapidly, within a few weeks of starting CO{sub 2} injection. Subsequently a two-phase water-CO{sub 2} mixture would be produced for a few years,followed by production of a single phase of supercritical CO{sub 2}. Even after single-phase production conditions are reached,significant dissolved water concentrations will persist in the CO{sub 2} stream for many years. The presence of dissolved water in the production stream has negligible impact on mass flow and heat transfer rates.

Pruess, K.; Spycher, N.

2009-05-01

403

Multi-cell storage battery  

DOEpatents

A multi-cell storage battery, in particular to a lithium storage battery, which contains a temperature control device and in which groups of one or more individual cells arranged alongside one another are separated from one another by a thermally insulating solid layer whose coefficient of thermal conductivity lies between 0.01 and 0.2 W/(m*K), the thermal resistance of the solid layer being greater by at least a factor .lambda. than the thermal resistance of the individual cell. The individual cell is connected, at least in a region free of insulating material, to a heat exchanger, the thermal resistance of the heat exchanger in the direction toward the neighboring cell being selected to be greater by at least a factor .lambda. than the thermal resistance of the individual cell and, in addition, the thermal resistance of the heat exchanger toward the temperature control medium being selected to be smaller by at least a factor of about 10 than the thermal resistance of the individual cell, and .lambda. being the ratio of the energy content of the individual cell to the amount of energy that is needed to trigger a thermally induced cell failure at a defined upper operating temperature limit.

Brohm, Thomas (Hattersheim, DE); Bottcher, Friedhelm (Kelkheim, DE)

2000-01-01

404

Carbon/ternary alloy/carbon optical stack on mylar as an optical data storage medium to potentially replace magnetic tape.  

PubMed

A novel write-once-read-many (WORM) optical stack on Mylar tape is proposed as a replacement for magnetic tape for archival data storage. This optical tape contains a cosputtered bismuth-tellurium-selenium (BTS) alloy as the write layer sandwiched between thin, protective films of reactively sputtered carbon. The composition and thickness of the BTS layer were confirmed by Rutherford Backscattering (RBS) and atomic force microscopy (AFM), respectively. The C/BTS/C stack on Mylar was written to/marked by 532 nm laser pulses. Under the same conditions, control Mylar films without the optical stack were unaffected. Marks, which showed craters/movement of the write material, were characterized by optical microscopy and AFM. The threshold laser powers for making marks on C/BTS/C stacks with different thicknesses were explored. Higher quality marks were made with a 60× objective compared to a 40× objective in our marking apparatus. The laser writing process was simulated with COMSOL. PMID:23964822

Wang, Hao; Lunt, Barry M; Gates, Richard J; Asplund, Matthew C; Shutthanandan, V; Davis, Robert C; Linford, Matthew R

2013-09-11

405

The effect of respiration heat of sorghum grain on the design of conditioned-air storage systems  

E-print Network

normally used for aeration (21). Knowing the initial condition of the grain, the condi- tions of the exhaust air can be calculated by using grain equilibrium data, In a recirculating system, the exhaust air represents the conditions of the air entering... Determinations. 25 10. Relationship of Respiration Heat to Temperature for Sorghum Grain at 14. 6 and 12. 4 Percent Moisture, Wet Basis, and Aerated with, Air Supplied at a Rate of 1/10 CFM per Bushel Relationship of Respiration Heat to Temperature...

Haile, Danel Gene

2012-06-07

406

Anaerobic Heat Production of Bull Spermatozoa. II. The Effects of Changes in the Colligative and Other Properties of the Suspending Medium  

Microsoft Academic Search

1. The anaerobic heat production of bull spermatozoa has been examined under varying environmental conditions, in an isothermal calorimeter, capacity 2.4 ml., working at atmospheric pressure. The minimum detectable heat production was 10 mu cal\\/min. The calorimeter was calibrated with needles containing plutonium oxide of known heat production, both now and in the future. 2. Abnormal environmental conditions or treatments,

Lord Rothschild

1959-01-01

407

Furan formation from fatty acids as a result of storage, gamma irradiation, UV-C and heat treatments.  

PubMed

The effects of gamma and UV-C irradiation in comparison with thermal processing and storage at 25°C on formation of furan from different fatty acids were investigated. Results showed that furan was generated from polyunsaturated fatty acids such as linoleic and linolenic acid during thermal (120°C, 25min) and UV-C (11.5J/cm(2)) treatments. Gamma irradiation (up to 20kGy) did not induce formation of significant amounts of furan from any of the fatty acids studied. Storage of unsaturated fatty acid emulsions at 25°C for 3days led to the formation of furan (7-11ng/mL) even without prior thermal or non-thermal treatments. pH significantly impacted furan formation with >3.5times more furan formed at pH 9 than at pHs 3 or 6 during 3days at 25°C. The addition of Trolox, BHA, and propyl gallate had no significant effect on furan formation from linolenic acid while ?-tocopherol and FeSO4 promoted furan formation. PMID:25577103

Fan, Xuetong

2015-05-15

408

Measured performance of a 1089 K (1500 deg F) heat storage device for sun-shade orbital missions  

NASA Technical Reports Server (NTRS)

Tubes designed for a solar heat receiver to serve as an energy source for a Brayton power system were tested for 2002 hours and 1251 sun-shade cycles. The tubes were designed to transfer a constant thermal input to the Brayton system during an orbit. Excess solar energy during a sun period is stored as heat of fusion of lithium fluoride. The niobium - 1% zirconium tubes accommodate the 23 percent volume decrease of LiF during freezing. Test results showed slight, local distortions. The gas discharge temperature varied from 16 K (29 F) below to 28 K (50 F) above the nominal value of 1089 K (1500 F). The tube surface temperatures ranged from 1039 K (1410 F) to 1183 K (1670 F).

Namkoong, D.

1972-01-01

409

COMMIX-SA-1: a three-dimensional thermohydrodynamic computer program for solar applications. [Heat-storage water tanks  

SciTech Connect

COMMIX-SA-1 is a three-dimensional, transient, single-phase, compressible-flow, component computer program for thermohydrodynamic analysis. It was developed for solar applications in general, and for analysis of thermocline storage tanks in particular. The conservation equations (in cylindrical coordinates) for mass, momentum, and energy are solved as an initial-boundary-value problem. The detailed numerical-solution procedure based on a modified ICE (Implicit Continuous-Fluid Eulerian) technique is described. A method for treating the singularity problem arising at the origin of a cylindrical-coordinate system is presented. In addition, the thermal interactions between fluid and structures (tank walls, baffles, etc.) are explicitly accounted for. Finally, the COMMIX-SA-1 code structure is delineated, and an input description and sample problems are presented.

Sha, W.T.; Lin, E.I.H.; Schmitt, R.C.; Liu, K.V.; Hull, J.R.; Oras, J.J. Jr.; Domanus, H.M.

1980-11-01

410

EFFECT OF RE-HEATING ON VIABILITY OF A 5-STRAIN MIXTURE OF L. MONOCYTOGENES IN VACUUM-SEALED PKGS OF FRANKFURTERS,COMMERCIALLY PREPARED WITH AND WITHOUT 2.0% POTASSIUM LACTATE, FOLLOWING REFRIGERATED OR FROZEN STORAGE  

Technology Transfer Automated Retrieval System (TEKTRAN)

The purpose of this study was to assess the effect of product formulation and storage times and temperatures on the viability of Listeria monocytogenes after re-heating of frankfurters. Individual links were inoculated with about 8.0 log10 CFU/package of a five-strain mixture of the pathogen, vacuu...

411

Thermal energy storage  

NASA Astrophysics Data System (ADS)

The Department of Energy (DOE) is supporting development of thermal energy storage (TES) as a means of efficiently coupling energy supplies to variable heating or cooling demands. Uses of TES include electrical demand-side management in buildings and industry, extending the utilization of renewable energy resources such as solar, and recovery of waste heat from periodic industrial processes. Technical progress to develop TES for specific diurnal and industrial applications under Oak Ridge National Laboratory's TES program from April 1990 to March 1992 is reported and covers research in the areas of low temperature sorption, direct contact ice making, latent heat storage plasterboard and latent/sensible heat regenerator technology development.

Tomlinson, J. J.

1992-03-01

412

Natural heat storage in a brine-filled solar pond in the Tully Valley of central New York  

USGS Publications Warehouse

The Tully Valley, located in southern Onondaga County, New York, has a long history of unusual natural hydrogeologic phenomena including mudboils (Kappel, 2009), landslides (Tamulonis and others, 2009; Pair and others, 2000), landsurface subsidence (Hackett and others, 2009; Kappel, 2009), and a brine-filled sinkhole or “Solar pond” (fig. 1), which is documented in this report. A solar pond is a pool of salty water (brine) which stores the sun’s energy in the form of heat. The saltwater naturally forms distinct layers with increasing density between transitional zones (haloclines) of rapidly changing specific conductance with depth. In a typical solar pond, the top layer has a low salt content and is often times referred to as the upper convective zone (Lu and others, 2002). The bottom layer is a concentrated brine that is either convective or temperature stratified dependent on the surrounding environment. Solar insolation is absorbed and stored in the lower, denser brine while the overlying halocline acts as an insulating layer and prevents heat from moving upwards from the lower zone (Lu and others, 2002). In the case of the Tully Valley solar pond, water within the pond can be over 90 degrees Fahrenheit (°F) in late summer and early fall. The purpose of this report is to summarize observations at the Tully Valley brine-filled sinkhole and provide supplemental climate data which might affect the pond salinity gradients insolation (solar energy).

Hayhurst, Brett; Kappel, William M.

2014-01-01

413

Investigation of the stability of paraffin-exfoliated graphite nanoplatelet composites for latent heat thermal storage systems  

SciTech Connect

Organic materials, such as paraffin wax, are sought as stable and environmentally friendly phase change materials (PCM) for thermal energy storage, but they suffer from low thermal conductivity which limits the rate at which thermal energy flows into and out of the material. A common method to improve the PCM thermal behavior is through loading with high thermal conductivity particulate fillers. However, the stability of these composites in the molten state is a concern as settling of the fillers will change the effective thermal conductivity. In this work, we investigate the stability of wax loaded with exfoliated graphite nanoplatelets either of 1 m (xGnP-1) or 15 m (xGnP-15) diameter. The effect of dispersants, oxidation of the wax, viscosity of the wax, mixing time, and hydrocarbon chain length on stability is reported. It was found that the addition of octadecylphosphonic acid (ODPA) is an effective dispersant for xGnP in paraffin and microcrystalline wax. In addition, mixing time, viscosity, and oxidation of the wax influence stability in the molten state. Overall, it was found that a mixing time of 24 hours for xGnP-15 along with ODPA mixed in a high viscosity, oxidized microcrystalline wax results in composite PCM systems with the greatest stability determined at 80 C in the molten state.

Abdelaziz, Omar [ORNL; Mallow, Anne [Georgia Institute of Technology; Graham, Samuel [Georgia Institute of Technology; Kalaitzidou, Kyriaki [Georgia Institute of Technology

2012-01-01

414

Influence of Long Time Storage in Mineral Water on RNA Stability of Pseudomonas aeruginosa and Escherichia coli after Heat Inactivation  

PubMed Central

Background Research of RNA viability markers was previously studied for many bacterial species. Few and different targets of each species have been checked and motley results can be found in literature. No research has been done about Pseudomonas aeruginosa in this way. Methodology/Principal Findings Disappearance of 48 transcripts was analyzed by two-steps reverse transcription and real time polymerase chain reaction (RT-PCR) after heat-killing of Pseudomonas aeruginosa previously stored in mineral water or not. Differential results were obtained for each target. 16S rRNA, 23S rRNA, groEL, and rpmE were showed as the most persistent transcripts and rplP, rplV, rplE and rpsD were showed as the most labile transcripts after P. aeruginosa death. However, the labile targets appeared more persistent in bacteria previously stored in mineral water than freshly cultivated (non stored). These nine transcripts were also analyzed in Escherichia coli after heat-killing and different to opposite results were obtained, notably for groEL which was the most labile transcript of E. coli. Moreover, opposite results were obtained between mineral water stored and freshly cultivated E. coli. Conclusions and Significance This study highlights four potential viability markers for P. aeruginosa and four highly persistent transcripts. In a near future, these targets could be associated to develop an efficient viability kit. The present study also suggests that it would be difficult to determine universal RNA viability markers for environmental bacteria, since opposite results were obtained depending on the bacterial species and the physiological conditions. PMID:18941615

Cenciarini, Claire; Courtois, Sophie; Raoult, Didier; La Scola, Bernard

2008-01-01

415

Thermal energy storage for power plant applications  

SciTech Connect

This study was conducted by Pacific Northwest Laboratory (PNL) to evaluate alternative methods of using coal to generate peak and intermediate load power. The approach was to review the technical and economic feasibility of using thermal energy storage (TES) with a conventional coal-fired power plant and an integrated gasification combined cycle (IGCC) power plant. In the first case, conventional pulverized coal combustion equipment was continuously operated to heat molten nitrate salt which was then stored in a tank. During peak demand periods, hot salt was withdrawn from storage and used to generate steam for a Rankine steam power cycle. This coal-fired salt heater can be approximately one-third the size of a coal-fired boiler in a conventional cycling plant. The use of nitrate salt TES also reduces the levelized cost of power from 5-24 percent depending on the operating schedule. The second case evaluates the use of thermal energy storage with an integrated gasification combined cycle (IGCC) power plant. In this case, the nitrate salt was heated by a combination of the gas turbine exhaust and the hot fuel gas. The IGCC plant also contained a low-temperature storage unit that uses a mixture of oil and rock as the thermal storage medium. Thermal energy stored in the low-temperature TES was used to preheat the feedwater after it leaves the condenser and to produce process steam for other applications in the IGCC plant. This concept study also predicted lower cost power compared to the natural gas-fired alternative if significant escalation rates in the price of fuel were assumed. A sensitivity analysis showed a significant reduction in the installed capital cost of a direct-contact heat exchanger instead of the conventional finnned-tube design.

Somasundaram, S.; Drost, M.K.; Antoniak, Z.I.; Brown, D.R. (Pacific Northwest Lab., Richland, WA (United States))

1990-01-01

416

Glass-heat-pipe evacuated-tube solar collector  

SciTech Connect

A glass heat pipe is adapted for use as a solar energy absorber in an evacuated tube solar collector and for transferring the absorbed solar energy to a working fluid medium or heat sink for storage or practical use. A capillary wick is formed of granular glass particles fused together by heat on the inside surface of the heat pipe with a water glass binder solution to enhance capillary drive distribution of the thermal transfer fluid in the heat pipe throughout the entire inside surface of the evaporator portion of the heat pipe. Selective coatings are used on the heat pipe surface to maximize solar absorption and minimize energy radiation, and the glass wick can alternatively be fabricated with granular particles of black glass or obsidian.

McConnell, R.D.; VanSant, J.H.

1981-08-06

417

Doping magnesium hydroxide with sodium nitrate: a new approach to tune the dehydration reactivity of heat-storage materials.  

PubMed

Thermochemical energy storage (TES) provides a challenging approach for improving the efficiency of various energy systems. Magnesium hydroxide, Mg(OH)2, is known as a suitable material for TES at temperature T>300 °C. In this work, the thermal decomposition of Mg(OH)2 in the absence and presence of sodium nitrate (NaNO3) is investigated to adapt this material for TES at T<300 °C. The most notable observations described for the doped Mg(OH)2 are (1) a significant reduction of the decomposition temperature Td that allows tuning the dehydration reactivity by varying the NaNO3 content. The Td decrease by 25 °C is revealed at a salt content Y?2.0 wt %. The maximum Td depression of some 50 °C is observed at Y=15-20 wt %; (2) the NaNO3-doped Mg(OH)2 decomposes considerably faster under conditions typical for closed TES cycles (at T>300 °C in vapor atmosphere) than a pure Mg(OH)2; (3) the morphology of the dehydration product (MgO) dramatically changes. Differential scanning calorimetry, high-resolution transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and vibrational spectroscopy (IR and Raman) are used to study the observed effects and to elucidate possible ways the NaNO3 influences the Mg(OH)2 dehydration and morphology of the dehydration product. The mechanism involving a chemical interaction between the salt and the hydroxide accompanied by nitrate embedding into brucite layers is discussed. PMID:25333760

Shkatulov, Alexandr; Krieger, Tamara; Zaikovskii, Vladimir; Chesalov, Yurii; Aristov, Yuri

2014-11-26

418

Heat Pipes  

NASA Technical Reports Server (NTRS)

Phoenix Refrigeration Systems, Inc.'s heat pipe addition to the Phoenix 2000, a supermarket rooftop refrigeration/air conditioning system, resulted from the company's participation in a field test of heat pipes. Originally developed by NASA to control temperatures in space electronic systems, the heat pipe is a simple, effective, heat transfer system. It has been used successfully in candy storage facilities where it has provided significant energy savings. Additional data is expected to fully quantify the impact of the heat pipes on supermarket air conditioning systems.

1991-01-01

419

Electricity storage using a thermal storage scheme  

NASA Astrophysics Data System (ADS)

The increasing use of renewable energy technologies for electricity generation, many of which have an unpredictably intermittent nature, will inevitably lead to a greater demand for large-scale electricity storage schemes. For example, the expanding fraction of electricity produced by wind turbines will require either backup or storage capacity to cover extended periods of wind lull. This paper describes a recently proposed storage scheme, referred to here as Pumped Thermal Storage (PTS), and which is based on "sensible heat" storage in large thermal reservoirs. During the charging phase, the system effectively operates as a high temperature-ratio heat pump, extracting heat from a cold reservoir and delivering heat to a hot one. In the discharge phase the processes are reversed and it operates as a heat engine. The round-trip efficiency is limited only by process irreversibilities (as opposed to Second Law limitations on the coefficient of performance and the thermal efficiency of the heat pump and heat engine respectively). PTS is currently being developed in both France and England. In both cases, the schemes operate on the Joule-Brayton (gas turbine) cycle, using argon as the working fluid. However, the French scheme proposes the use of turbomachinery for compression and expansion, whereas for that being developed in England reciprocating devices are proposed. The current paper focuses on the impact of the various process irreversibilities on the thermodynamic round-trip efficiency of the scheme. Consideration is given to compression and expansion losses and pressure losses (in pipe-work, valves and thermal reservoirs); heat transfer related irreversibility in the thermal reservoirs is discussed but not included in the analysis. Results are presented demonstrating how the various loss parameters and operating conditions influence the overall performance.

White, Alexander

2015-01-01

420

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

SciTech Connect

Berkeley Lab has for several years been developing methods for selection of optimal microgrid systems, especially for commercial building applications, and applying these methods in the Distributed Energy Resources Customer Adoption Model (DER-CAM). 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 power quality and reliability (PQR) to the capabilities of DER-CAM. All of these objectives have been pursued via analysis of the attractiveness of a Consortium for Electric Reliability Technology Solutions (CERTS) Microgrid consisting of multiple nameplate 100 kW Tecogen Premium Power Modules (CM-100). This unit consists of an asynchronous inverter-based variable speed internal combustion engine genset with combined heat and power (CHP) and power surge capability. The essence of CERTS Microgrid technology is that smarts added to the on-board power electronics of any microgrid device enables stable and safe islanded operation without the need for complex fast supervisory controls. This approach allows plug and play development of a microgrid that can potentially provide high PQR with a minimum of specialized site-specific engineering. A notable feature of the CM-100 is its time-limited surge rating of 125 kW, and DER-CAM capability to model this feature was also a necessary model enhancement.

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

2009-03-10

421

THERMAL ENERGY STORAGE IN AQUIFERS WORKSHOP  

E-print Network

ground water by means of a basic heat exchange system and transfersof heat storage in the ground, in- transfer properties. Atground- water and rocks must be cooled to the injection water temperature. From preliminary heat transfer

Authors, Various

2011-01-01

422

Case histories in scientific and pseudo-scientific mass-media communication in energy/heat production from underground (geogas storage, geothermics, hydrocarbons), in the frame of Nimby Sindrome enhancement in Europe: the proposal of a new European Direct  

NASA Astrophysics Data System (ADS)

In the frame of energy/heat production from underground, the paper considers some European case histories and the needs of a complex and motley stakeholders community, made by scientific-industry-institutions, involved in the difficult task to study and accept (or refuse) projects strongly impacting the lived territory & underground, in densely populate countries, as Italy, in terms of appropriate public communication and sound deontological behaviour. Successively, the paper recalls years of "scientific" communication within the mass-media, highlighting the positive and negative messages, in comparison to the true and objective experimental data gathered by the real scientific work, as perceived by citizens of medium scholastic culture, which not delve the geologic disciplines, but receive simply the journalistic front-end, very often as sensationalist scoop. The authors retrace case histories of heuristic-participatory communication with the citizenship about the scientific results on challenges raised by certain technologies. The objective and rational communication is often impeded by local interests and by local journalism, which prefers to create sensationalist news more than scientific truths. This path progressively tangles as a consequence of the complex and with conflicting use of underground to produce energy (heat as gas storage, geothermical, unconventional gas exploitation, mining, etc…). Even the chain of renewables meets by now serious issues, exacerbated also by the need to start mining and drilling for the smart grids materials too (metals, rare Earths, etc..). A new text for a smart and innovative European Directivity is discussed, starting from the Italian regulatory issue. The review efforts for a "paper" on both a newspaper or a blog could be more difficult than the review a scientific paper, as a consequence of the peculiar situations behind the scenes and the conflicts of interests staying in the nest in a newspaper article or in a blog comment (locally political interests, commercial interests, attention-seeking, colleagues envies, etc..). The scientific journalists are normally of low scientific and ethical level and they are often coopted by negative mechanisms (mainly political for some newspapers or TV). The paper travel over again the AAPG rule of ethics (American Association of Petroleum Geology), taking the advantage of certain concepts developed by Nomisma Energia too and of concepts coming from our work, building energy-related questionnaires, also with municipalities affected by disastrous geological adverseness (i.e., earthquakes, contamination, slides, floods), even managing infrastructures of energetic production from underground (rims, storage, geothermics, etc…). In conclusions we suggest a "scientific journalist licence" (from Italy this kind of skill is escaping) and grave procedures of "Hyppocrates adjuratory" for scientific journalists as well as for scientific community and operators involved in the sector. The case histories reported emblematic of how the road is long, meandrous but necessary.

Quattrocchi, Fedora; Boschi, Enzo

2014-05-01

423

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

PubMed

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 (40-48 degrees C) and UV-C doses (0.05-1.50 J/cm2). For each condition, 20 berries were used. After the treatment, fungal growth, visual damage (holes, stains) and fruit firmness were evaluated during a period of 10 days. The experimental data were analysed statistically using survival analysis techniques. Fungal growth on strawberries was significantly retarded using UV-C doses of 0.05 J/cm2 and higher. The same treatment had no significant effect when applied to cherries. The highest doses (1.00 and 1.50 J/cm2) had a negative effect on the calyx of the strawberry, causing browning and drying of the leaves. No beneficial effect of a low temperature treatment (40-48 degrees C) on the shelf life of strawberries was observed, but fungal development on cherries was retarded at temperatures of 45 and 48 degrees C. These temperatures caused severe damage on strawberries (soft stains, holes, decreased firmness), but had no influence on the quality of sweet cherries. PMID:11934026

Marquenie, D; Michiels, C W; Geeraerd, A H; Schenk, A; Soontjen, C; Van Impe, J F; Nicolaï, B M

2002-03-01

424

Versatile structure-directing roles of deep-eutectic solvents and their implication in the generation of porosity and open metal sites for gas storage.  

PubMed

Trap it in and burn it out: A deep-eutectic solvent provides a versatile medium for the creation of highly stable porous frameworks encapsulating neutral coordinating ligand molecules, which can escape intact from the pores upon heating to form crystals directly, leaving behind permanent porosity and coordinatively unsaturated metal sites with potential applications in gas storage and catalysis. PMID:19343752

Zhang, Jian; Wu, Tao; Chen, Shumei; Feng, Pingyun; Bu, Xianhui

2009-01-01

425

Fluidized bed heat treating system  

DOEpatents

Systems for heat treating materials are presented. The systems typically involve a fluidized bed that contains granulated heat treating material. In some embodiments a fluid, such as an inert gas, is flowed through the granulated heat treating medium, which homogenizes the temperature of the heat treating medium. In some embodiments the fluid may be heated in a heating vessel and flowed into the process chamber where the fluid is then flowed through the granulated heat treating medium. In some embodiments the heat treating material may be liquid or granulated heat treating material and the heat treating material may be circulated through a heating vessel into a process chamber where the heat treating material contacts the material to be heat treated. Microwave energy may be used to provide the source of heat for heat treating systems.

Ripley, Edward B; Pfennigwerth, Glenn L

2014-05-06

426

Conjugate Effects of Heat and Mass Transfer on MHD Free Convection Flow over an Inclined Plate Embedded in a Porous Medium  

PubMed Central

The aim of this study is to present an exact analysis of combined effects of radiation and chemical reaction on the magnetohydrodynamic (MHD) free convection flow of an electrically conducting incompressible viscous fluid over an inclined plate embedded in a porous medium. The impulsively started plate with variable temperature and mass diffusion is considered. The dimensionless momentum equation coupled with the energy and mass diffusion equations are analytically solved using the Laplace transform method. Expressions for velocity, temperature and concentration fields are obtained. They satisfy all imposed initial and boundary conditions and can be reduced, as special cases, to some known solutions from the literature. Expressions for skin friction, Nusselt number and Sherwood number are also obtained. Finally, the effects of pertinent parameters on velocity, temperature and concentration profiles are graphically displayed whereas the variations in skin friction, Nusselt number and Sherwood number are shown through tables. PMID:23840321

Ali, Farhad; Khan, Ilyas; Samiulhaq; Shafie, Sharidan

2013-01-01

427

Conjugate effects of heat and mass transfer on MHD free convection flow over an inclined plate embedded in a porous medium.  

PubMed

The aim of this study is to present an exact analysis of combined effects of radiation and chemical reaction on the magnetohydrodynamic (MHD) free convection flow of an electrically conducting incompressible viscous fluid over an inclined plate embedded in a porous medium. The impulsively started plate with variable temperature and mass diffusion is considered. The dimensionless momentum equation coupled with the energy and mass diffusion equations are analytically solved using the Laplace transform method. Expressions for velocity, temperature and concentration fields are obtained. They satisfy all imposed initial and boundary conditions and can be reduced, as special cases, to some known solutions from the literature. Expressions for skin friction, Nusselt number and Sherwood number are also obtained. Finally, the effects of pertinent parameters on velocity, temperature and concentration profiles are graphically displayed whereas the variations in skin friction, Nusselt number and Sherwood number are shown through tables. PMID:23840321

Ali, Farhad; Khan, Ilyas; Samiulhaq; Shafie, Sharidan

2013-01-01

428

RETRACTION: Unsteady flow and heat transfer of viscous incompressible fluid with temperature-dependent viscosity due to a rotating disc in a porous medium  

NASA Astrophysics Data System (ADS)

It has come to the attention of the Institute of Physics that this article should not have been submitted for publication owing to its plagiarism of an earlier paper (Hossain A, Hossain M A and Wilson M 2001 Unsteady flow of viscous incompressible fluid with temperature-dependent viscosity due to a rotating disc in presence of transverse magnetic field and heat transfer Int. J. Therm. Sci. 40 11-20). Therefore this article has been retracted by the Institute of Physics and by the author, Hazem Ali Attia.

Attia, H. A.

2007-04-01

429

Unsteady MHD flow and heat transfer near stagnation point over a stretching/shrinking sheet in porous medium filled with a nanofluid  

NASA Astrophysics Data System (ADS)

In this article, the unsteady magnetohydrodynamic (MHD) stagnation point flow and heat transfer of a nanofluid over a stretching/shrinking sheet is investigated numerically. The similarity solution is used to reduce the governing system of partial differential equations to a set of nonlinear ordinary differential equations which are then solved numerically using the fourth-order Runge-Kutta method with shooting technique. The ambient fluid velocity, stretching/shrinking velocity of sheet, and the wall temperature are assumed to vary linearly with the distance from the stagnation point. To investigate the influence of various pertinent parameters, graphical results for the local Nusselt number, the skin friction coefficient, velocity profile, and temperature profile are presented for different values of the governing parameters for three types of nanoparticles, namely copper, alumina, and titania in the water-based fluid. It is found that the dual solution exists for the decelerating flow. Numerical results show that the extent of the dual solution domain increases with the increases of velocity ratio, magnetic parameter, and permeability parameter whereas it remains constant as the value of solid volume fraction of nanoparticles changes. Also, it is found that permeability parameter has a greater effect on the flow and heat transfer of a nanofluid than the magnetic parameter.

Sadegh, Khalili; Saeed, Dinarvand; Reza, Hosseini; Hossein, Tamim; Ioan, Pop

2014-04-01

430

Solar heating in France  

Microsoft Academic Search

The operation of eight solar heating installations in private dwellings in the south of France is described. All of the installations discussed utilize flat plate collectors. The storage cylinders are of the indirect type, with a coil in the bottom through which solar heated water is circulated. Installations with 4 sq m collectors and 300 liters storage can provide domestic

B. Carter

1976-01-01

431

Tomorrow`s energy today for cities and counties - keep it cool with thermal energy storage  

SciTech Connect

Cool thermal energy storage (TES) is described as a means for electric utilities to provide electricity from off-peak times, particularly in the summer when air-conditioning accounts for 50% or more of electricity consumption. Cool TES uses off-peak power to provide cooling capacity by extracting heat from a storage medium such as ice or other phase change material. A refrigeration system may may be utilized at night to provide a reservoir of cold material. During the day, the reservoir is tapped to provide cooling capacity. The advantages of TES are discussed.

NONE

1995-07-01

432

Heat and mass transfer for Soret and Dufour’s effect on mixed convection boundary layer flow over a stretching vertical surface in a porous medium filled with a viscoelastic fluid  

NASA Astrophysics Data System (ADS)

A mathematical model is analyzed in order to study the heat and mass transfer characteristics in mixed convection boundary layer flow about a linearly stretching vertical surface in a porous medium filled with a viscoelastic fluid, by taking into account the diffusion-thermo (Dufour) and thermal-diffusion (Soret) effects. The governing partial differential equations are transformed into a set of coupled ordinary differential equations, which are solved analytically using the homotopy analysis method (HAM) to determine the convergent series expressions of velocity, temperature and concentration. The physical interpretation to these expressions is assigned through graphs and a table for the wall shear stress f(0), Nusselt number -?'(0) and Sherwood number -?'(0). Results showed that the fields were influenced appreciably by the effects of the governing parameters: mixed convection parameter ?, Lewis number Le, Prandtl number Pr, viscoelastic parameter K, concentration buoyancy parameter N, porosity parameter ?, Dufour number Df and Soret number Sr. It was evident that for some kind of mixtures such as the light and medium molecular weight, the Soret and Dufour's effects should be considered as well.

Hayat, T.; Mustafa, M.; Pop, I.

2010-05-01

433

Open systems storage platforms  

NASA Technical Reports Server (NTRS)

The building blocks for an open storage system includes a system platform, a selection of storage devices and interfaces, system software, and storage applications CONVEX storage systems are based on the DS Series Data Server systems. These systems are a variant of the C3200 supercomputer with expanded I/O capabilities. These systems support a variety of medium and high speed interfaces to networks and peripherals. System software is provided in the form of ConvexOS, a POSIX compliant derivative of 4.3BSD UNIX. Storage applications include products such as UNITREE and EMASS. With the DS Series of storage systems, Convex has developed a set of products which provide open system solutions for storage management applications. The systems are highly modular, assembled from off the shelf components with industry standard interfaces. The C Series system architecture provides a stable base, with the performance and reliability of a general purpose platform. This combination of a proven system architecture with a variety of choices in peripherals and application software allows wide flexibility in configurations, and delivers the benefits of open systems to the mass storage world.

Collins, Kirby

1992-01-01

434

Finite-difference model of two-dimensional, single, and two-phase heat transport in a porous medium - Version I  

USGS Publications Warehouse

Model documentation is presented for a two-dimensional (areal) heat-transport model capable of simulating both water- and vapor-dominated geothermal reservoirs that conform with the assumptions of the model. Finite-difference techniques are used to solve for the dependent variables pressure and enthalpy. The program is designed to simulate time-dependent problems such as those associated with geothermal reservoirs undergoing exploitation, and can treat the transition from compressed water to two-phase flow. In order to simulate more complicated field problems the present program is being extended, and therefore the model described in this report is referred to as VERSION I. A listing of the computer code is included. (Woodard-USGS)

Faust, Charles R.; Mercer, James W.

1977-01-01

435

Heat and mass transfer in unsaturated porous media. Final report  

SciTech Connect

A preliminary study of heat and water transport in unsaturated porous media is reported. The project provides background information regarding the feasibility of seasonal thermal energy storage in unconfined aquifers. A parametric analysis of the factors of importance, and an annotated bibliography of research findings pertinent to unconfined aquifer thermal energy storage (ATES) are presented. This analysis shows that heat and mass transfer of water vapor assume dominant importance in unsaturated porous media at elevated temperature. Although water vapor fluxes are seldom as large as saturated medium liquid water fluxes, they are important under unsaturated conditions. The major heat transport mechanism for unsaturated porous media at temperatures from 50 to 90/sup 0/C is latent heat flux. The mechanism is nonexistent under saturated conditions but may well control design of unconfined aquifer storage systems. The parametric analysis treats detailed physical phenomena which occur in the flow systems study and demonstrates the temperature and moisture dependence of the transport coefficients of importance. The question of design of an unconfined ATES site is also addressed by considering the effects of aquifer temperature, depth to water table, porous medium flow properties, and surface boundary conditions. Recommendations are made for continuation of this project in its second phase. Both scientific and engineering goals are considered and alternatives are presented.

Childs, S.W.; Malstaff, G.

1982-02-01

436

Solar heating system  

DOEpatents

An improved solar heating system in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75.degree. to 180.degree. F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing and releasing heat for distribution.

Schreyer, James M. (Oak Ridge, TN); Dorsey, George F. (Concord, TN)

1982-01-01

437

Development of encapsulated lithium hydride thermal energy storage for space power systems  

SciTech Connect

Inclusion of thermal energy storage in a pulsed space power supply will reduce the mass of the heat rejection system. In this mode, waste heat generated during the brief high-power burst operation is placed in the thermal store; later, the heat in the store is dissipated to space via the radiator over the much longer nonoperational period of the orbit. Thus, the radiator required is of significantly smaller capacity. Scoping analysis indicates that use of lithium hydride as the thermal storage medium results in system mass reduction benefits for burst periods as long as 800 s. A candidate design for the thermal energy storage component utilizes lithium hydride encapsulated in either 304L stainless steel or molybdenum in a packed-bed configuration with a lithium or sodium-potassium (NaK) heat transport fluid. Key issues associated with the system design include phase-change induced stresses in the shell, lithium hydride and shell compatibility, lithium hydride dissociation and hydrogen loss from the system, void presence and movement associated with the melt-freeze process, and heat transfer limitations on obtaining the desired energy storage density. 58 refs., 40 figs., 11 tabs.

Morris, D.G.; Foote, J.P.; Olszewski, M.

1987-12-01

438

Investigation of metal fluoride thermal energy storage materials: availability, cost, and chemistry. Final report, July 15, 1976--December 15, 1976  

SciTech Connect

Storage of thermal energy in the 400 to 1000/sup 0/C range is attracting increasing consideration for use in solar power, central power, vehicular, and commercial process systems. This study investigates the practicality of using metal fluorides as the heat storage medium. The projected availability of metal fluorides has been studied and is shown to be adequate for widespread thermal storage use. Costs are projected and discussed in relation to thermal energy storage applications. Phase diagrams, heats of fusion, heat capacities, vapor pressures, toxicity, stability, volume changes, thermal conductivities, fusion kinetics, corrosion, and container materials of construction for a wide range of fluorides have been examined. Analyses of these data in consideration of thermal energy storage requirements have resulted in selection of the most cost-effective fluoride mixture for each of 23 temperature increments between 400 and 1000/sup 0/C. Thermo-physical properties of these 23 materials are presented. Comparison of fluoride with non-fluoride materials shows that the fluorides are suitable candidates for high temperature applications on the bases of cost, heat capacity/unit volume, heat capacity/unit weight, corrosive properties, and availability.

Eichelberger, J.L.

1976-12-01

439

Solar heating and hot water system installed at Listerhill, Alabama  

NASA Technical Reports Server (NTRS)

The Solar system was installed into a new building and was designed to provide 79% of the estimated annual space heating load and 59% of the estimated annual potable hot water requirement. The collectors are flat plate, liquid manufactured by Reynolds Metals Company and cover a total area of 2344 square feet. The storage medium is water inhibited with NALCO 2755 and the container is an underground, unpressurized steel tank with a capacity of 5000 gallons. This report describes in considerable detail the solar heating facility and contains detailed drawings of the completed system.

1978-01-01

440

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

E-print Network

300 kW to 2.4 MW. Electric efficiencies of 42% (HHV) can beCHP systems. The electric efficiency is approximately 35% (Electric and Thermal Storage Technologies”, ACEEE 2008 Summer Study on Energy Efficiency

Stadler, Michael

2009-01-01

441

Thermal Energy Storage: Fourth Annual Review Meeting  

NASA Technical Reports Server (NTRS)

The development of low cost thermal energy storage technologies is discussed in terms of near term oil savings, solar energy applications, and dispersed energy systems for energy conservation policies. Program definition and assessment and research and technology development are considered along with industrial storage, solar thermal power storage, building heating and cooling, and seasonal thermal storage. A bibliography on seasonal thermal energy storage emphasizing aquifer thermal energy is included.

1980-01-01

442

Cyclic injection, storage, and withdrawal of heated water in a sandstone aquifer at St. Paul, Minnesota; analysis of thermal data and nonisothermal modeling of short-term test cycles  

USGS Publications Warehouse

In May 1980, the University of Minnesota began a project to evaluate the feasibility of storing heated water (150 degree Celsius) in the deep Franconia-Ironton-Galesville aquifer (180 to 240 meters below land surface) and later recovering it for space heating. High-temperature water from the University's steam-generation facilities supplied heated water for injection. The Aquifer Thermal- Energy Storage system is a doublet-well design in which the injection/withdrawal wells are spaced approximately 250 meters apart. Water was pumped from one of the wells through a heat exchanger, where heat was added or removed. This water was then injected back into the aquifer through another well. Four short-term test cycles were completed. Each cycle consisted of approximately equal durations of injection, and withdrawal. Equal rates of injection and withdrawal, ranging from 17.7 to 18.4 liters per second, were maintained for each short-term test cycle. Injection temperatures ranged from 88.5 to 117.9 degrees Celsius. A three-dimensional, anisotropic, noniso- thermal ground-water flow and thermal-energy- transport model was constructed to simulate the four short-term test cycles. The only model properties varied during model calibration were longitudinal and transverse thermal dispersivities. The model was calibrated by comparing model-computed results to (1) field-recorded temperatures at selected locations, in four observation wells; (2) field- recorded temperatures at the production well; and (3) calculated aquifer-thermal efficiences. Model- computed withdrawal-water temperaturs were within an average of about 3 percent of measured values and model-computed aquifer-thermal efficiencies were within an average of about 5 percent of calculated values for the short-term test cycles. These data indicate that the model accurately simulated thermal-energy storage.

Miller, Robert T.; Delin, G.N.

1994-01-01

443

Short term thermal energy storage Institut fr Kernenergetik und Energiesysteme, University of Stuttgart, Stuttgart, FRG  

E-print Network

phase change heat storage materials. Finally, some data pertaining to the current economics ofheat storage tanks is described. Concerning latent heat storage, both material and heat exchanger aspects heat exchanger is used to elaborate upon the heat transfer problems in the generally poorly conducting

Paris-Sud XI, Université de

444

Optical memory development. Volume 2: Gain-assisted holographic storage media  

NASA Technical Reports Server (NTRS)

Thin deformable films were investigated for use as the storage medium in a holographic optical memory. The research was directed toward solving the problems of material fatigue, selective heat addressing, electrical charging of the film surface and charge patterning by light. A number of solutions to these problems were found but the main conclusion to be drawn from the work is that deformable media which employ heat in the recording process are not satisfactory for use in a high-speed random-access read/write holographic memory. They are, however, a viable approach in applications where either high speed or random-access is not required.

Gange, R. A.; Mezrich, R. S.

1972-01-01

445

Heat transfer in microwave heating  

NASA Astrophysics Data System (ADS)

Heat transfer is considered as one of the most critical issues for design and implement of large-scale microwave heating systems, in which improvement of the microwave absorption of materials and suppression of uneven temperature distribution are the two main objectives. The present work focuses on the analysis of heat transfer in microwave heating for achieving highly efficient microwave assisted steelmaking through the investigations on the following aspects: (1) characterization of microwave dissipation using the derived equations, (2) quantification of magnetic loss, (3) determination of microwave absorption properties of materials, (4) modeling of microwave propagation, (5) simulation of heat transfer, and (6) improvement of microwave absorption and heating uniformity. Microwave heating is attributed to the heat generation in materials, which depends on the microwave dissipation. To theoretically characterize microwave heating, simplified equations for determining the transverse electromagnetic mode (TEM) power penetration depth, microwave field attenuation length, and half-power depth of microwaves in materials having both magnetic and dielectric responses were derived. It was followed by developing a simplified equation for quantifying magnetic loss in materials under microwave irradiation to demonstrate the importance of magnetic loss in microwave heating. The permittivity and permeability measurements of various materials, namely, hematite, magnetite concentrate, wüstite, and coal were performed. Microwave loss calculations for these materials were carried out. It is suggested that magnetic loss can play a major role in the