Sample records for heat storage medium

  1. Medium Deep High Temperature Heat Storage

    NASA Astrophysics Data System (ADS)

    Bär, Kristian; Rühaak, Wolfram; Schulte, Daniel; Welsch, Bastian; Chauhan, Swarup; Homuth, Sebastian; Sass, Ingo

    2015-04-01

    Heating of buildings requires more than 25 % of the total end energy consumption in Germany. Shallow geothermal systems for indirect use as well as shallow geothermal heat storage systems like aquifer thermal energy storage (ATES) or borehole thermal energy storage (BTES) typically provide low exergy heat. The temperature levels and ranges typically require a coupling with heat pumps. By storing hot water from solar panels or thermal power stations with temperatures of up to 110 °C a medium deep high temperature heat storage (MDHTS) can be operated on relatively high temperature levels of more than 45 °C. Storage depths of 500 m to 1,500 m below surface avoid conflicts with groundwater use for drinking water or other purposes. Permeability is typically also decreasing with greater depth; especially in the crystalline basement therefore conduction becomes the dominant heat transport process. Solar-thermal charging of a MDHTS is a very beneficial option for supplying heat in urban and rural systems. Feasibility and design criteria of different system configurations (depth, distance and number of BHE) are discussed. One system is designed to store and supply heat (300 kW) for an office building. The required boreholes are located in granodioritic bedrock. Resulting from this setup several challenges have to be addressed. The drilling and completion has to be planned carefully under consideration of the geological and tectonical situation at the specific site.

  2. Heat storage device

    SciTech Connect

    Gawron, K.; Mahdjuri, F.; Schroder, J.

    1980-09-02

    A heat storage device is described that is comprised of a closed reservoir within which is positioned a flexible closed container of smaller volume. The flexible container encloses a liquefiable heat-accumulating material; and the reservoir is provided with a heat-transport medium outside of the flexible container. The heat-transport medium always remains in the liquid phase and, upon solidification and shrinkage of the heat-accumulating material, fills the spaces thus formed between the flexible container and the reservoir wall in order to maintain adequate transfer of heat.

  3. Heat storage material

    SciTech Connect

    Mita, N.; Murai, Y.; Sato, A.

    1982-01-05

    A heat storage material having a melting point in the range of 90* to 100* C is described. It is excellent in that it is neither corrosiv inflammable nor toxic. The heat storage material comprises a mixture of dimethyl terephthalate and one member selected from the group consisting of dimethyl fumarate and dihydroanthracene.

  4. Advanced solar thermal storage medium test data and analysis

    NASA Technical Reports Server (NTRS)

    Saha, H.

    1981-01-01

    A comparative study has been made of experimentally obtained heat transfer and heat storage characteristics of a solar thermal energy storage bed utilizing containerized water or phase change material (PCM) and rock or brick. It is shown that (1) containers with an L/D ratio of 0.80 and a mass/surface area ratio of 2.74 in a random stacking arrangement have the optimum heat transfer characteristics; and (2) vertical stacking has the least pressure drop across the test bed. It is also found that standard bricks with appropriate holes make an excellent storage medium.

  5. Heat transfer efficient thermal energy storage for steam generation

    Microsoft Academic Search

    R. Adinberg; D. Zvegilsky; M. Epstein

    2010-01-01

    A novel reflux heat transfer storage (RHTS) concept for producing high-temperature superheated steam in the temperature range 350–400°C was developed and tested. The thermal storage medium is a metallic substance, Zinc–Tin alloy, which serves as the phase change material (PCM). A high-temperature heat transfer fluid (HTF) is added to the storage medium in order to enhance heat exchange within the

  6. Low temperature latent heat thermal energy storage - Heat storage materials

    Microsoft Academic Search

    A. Abhat

    1983-01-01

    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

  7. Overview of medium scale energy storage systems

    Microsoft Academic Search

    M. A. Guerrero; E. Romero; F. Barrero; M. I. Milanes; E. Gonzalez

    2009-01-01

    In this paper, an overview of energy storage systems alternatives to use in medium energy scale applications is done. The considered technologies are compressed air, pumped hydro, superconductors, flywheels and supercapacitors. The last four are suitable for the medium scale applications (as 100 kW photovoltaic generation plants) which this paper is focused on. The supercapacitor alternative is studied in more

  8. Heat storage material comprising lithium chlorate-trihydrate and a nucleating agent

    SciTech Connect

    Gawron, K.; Schroder, J.

    1980-02-19

    A heat storage material comprising lithium chlorate-trihydrate as the heat storage medium and potassium perchlorate and/or sodium, potassium or barium hexafluorosilicate as the nucleating agent to reduce supercooling.

  9. Static solar heat storage composition

    SciTech Connect

    Phillips, H.J.

    1981-09-08

    A composition for the storage of heat energy utilizing the heat of fusion of the composition. The composition includes a salthydrate, a nucleating agent and a porous solid. The porous solid is selected from calcium sulfate hemihydrate and soluble calcium sulfate anhydride.

  10. Heat resistance of Escherichia coli O157:H7 in a nutrient medium and in ground beef patties as influenced by storage and holding temperatures.

    PubMed

    Jackson, T C; Hardin, M D; Acuff, G R

    1996-03-01

    Stationary-phase cultures of Escherichia coli O157:H7 were inoculated into tryptic soy broth, sealed in vials, and stored at -18 degrees C for 1, 8, and 15 days, or 3 or 15 degrees C for 3, 6, and 9 h. Thermal resistance was determined at 55 degrees C. Each storage treatment was repeated with additional holding at 23 or 30 degrees C for 1, 2, 3, or 4 h prior to heating to simulate potential temperature abuse during handling. Cultures under treatments enabling the growth of E. coli O157:H7 were generally more heat sensitive than those held at temperatures which restricted growth or enabled growth to stationary phase. Cultures stored frozen (-18 degrees C) without holding at elevated temperatures had greater heat resistance than those stored under refrigeration (3 degrees C) or at 15 degrees C. Subsequent holding of frozen cultures at 23 or 30 degrees C resulted in a decrease in heat resistance. To determine whether these responses would be observed under typical commercial preparation procedures, ground beef patties were inoculated with E. coli O157:H7 and stored at 3 or 15 degrees C for 9 h or at -18 degrees C for 8 d and then held at 21 or 30 degrees C for 0 or 4 h. Patties were grilled to an internal temperature of 54.4 degrees C (130 degrees F), 62.8 degrees C (145 degrees F), or 68.3 degrees C (155 degrees F). Cultures were most resistant in frozen patties, while cultures in patties stored at 15 degrees C were the most heat sensitive. Holding patties at 21 or 30 degrees C prior to grilling resulted in increased sensitivity. Storage and holding temperatures similar to those encountered in food service may influence the ability of E. coli O157:H7 to survive heat treatments. PMID:10463438

  11. Heat storage in alloy transformations

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

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

  12. Fluid heating system with storage of electric heat

    Microsoft Academic Search

    McKenney

    1981-01-01

    A heating system includes a heat storage tank containing a heat transfer fluid (Water) electrically heated to a high temperature. A tube\\/shell heat exchanger having a pair of fluid flow paths arranged in counter flow relationship is provided for extraction of heat from storage tank by the circulation of the heat transfer fluid therethrough. Conduit means connect the outlet of

  13. Solar heat storage in phase change material

    Microsoft Academic Search

    1984-01-01

    The objective of this project was to develop a chemical heat storage system that had a phase change with release of latent heat at about 105°F. The primary reason this kind on system was sought was that heat storage capacity of commonly used storage systems do not match the heat collection capacity of open air collectors. In addition to the

  14. THERMOCHEMICAL HEAT STORAGE FOR CONCENTRATED; SOLAR POWER

    Microsoft Academic Search

    2011-01-01

    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

  15. Metal-halide mixtures for latent heat energy storage

    NASA Technical Reports Server (NTRS)

    Chen, K.; Manvi, R.

    1981-01-01

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

  16. Phase-Change Heat-Storage Module

    NASA Technical Reports Server (NTRS)

    Mulligan, James C.

    1989-01-01

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

  17. Heat-storage materials for IRCM

    Microsoft Academic Search

    J. C. Cooper; D. D. Lindsay

    1983-01-01

    The use of heat-storage materials was evaluated for flattening and extending the temperature-time profile of pyrophoric materials as thermal emission sources. Materials with large heats of fusion or large enthalpy changes in reversible chemical reactions would be useable as heat-storage materials.

  18. Heat-storage materials for IRCM

    NASA Astrophysics Data System (ADS)

    Cooper, J. C.; Lindsay, D. D.

    1983-09-01

    The use of heat-storage materials was evaluated for flattening and extending the temperature-time profile of pyrophoric materials as thermal emission sources. Materials with large heats of fusion or large enthalpy changes in reversible chemical reactions would be useable as heat-storage materials.

  19. Heat storage in alloy transformations

    NASA Astrophysics Data System (ADS)

    Birchenall, C. E.

    1980-03-01

    Heats of transformation of eutectic alloys were measured for many binary and ternary systems by differential scanning calorimetry and thermal analysis. Only the relatively cheap and plentiful elements Mg, Al, Si, P, Ca, Cu, Zn were considered. A method for measuring volume change during transformation was developed using x-ray absorption in a confined sample. Thermal expansion coefficients of both solid and liquid states of aluminum and of its eutectics with copper and with silicon also were determined. Preliminary evaluation of containment materials lead to the selection of silicon carbide as the initial material for study. Possible applications of alloy PCMs for heat storage in conventional and solar central power stations, small solar receivers and industrial furnace operations are under consideration.

  20. Heat storage in alloy transformations

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    The feasibility of using metal alloys as thermal energy storage media was determined. The following major elements were studied: (1) identification of congruently transforming alloys and thermochemical property measurements; (2) development of a precise and convenient method for measuring volume change during phase transformation and thermal expansion coefficients; (3) development of a numerical modeling routine for calculating heat flow in cylindrical heat exchangers containing phase change materials; and (4) identification of materials that could be used to contain the metal alloys. Several eutectic alloys and ternary intermetallic phases were determined. A method employing X-ray absorption techniques was developed to determine the coefficients of thermal expansion of both the solid and liquid phases and the volume change during phase transformation from data obtained during one continuous experimental test. The method and apparatus are discussed and the experimental results are presented. The development of the numerical modeling method is presented and results are discussed for both salt and metal alloy phase change media.

  1. Air medium solar heating system. Final report

    Microsoft Academic Search

    2008-01-01

    A demonstration of an air medium solar heating system retrofitted to an existing dwelling in a northern climate, latitude 48°N, is described. The collector measures 64 ft in length by 8 ft high and is located 40 ft from the dwelling. The air transfer is accomplished via 2 - 12 in. round PVC air ducts insulated with 1 in. of

  2. Heat storage in alloy transformations

    NASA Technical Reports Server (NTRS)

    Birchenall, C. E.

    1980-01-01

    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.

  3. Heat storage in alloy transformations

    NASA Astrophysics Data System (ADS)

    Birchenall, C. E.

    1980-04-01

    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.

  4. Waste-heat recovery in batch processes using heat storage

    Microsoft Academic Search

    S. Stoltze; J. Mikkelsen; B. Lorentzen; P. M. Petersen; B. Qvale

    1995-01-01

    The waste-heat recovery in batch processes has been studied using the pinch-point method. The aim of the work has been to investigate theoretical and practical approaches to the design of heat-exchanger networks, including heat storage, for waste-heat recovery in batch processes. The study is limited to the incorporation of energy-storage systems based on fixed-temperature variable-mass stores. The background for preferring

  5. Waste-heat recovery in batch processes using heat storage

    SciTech Connect

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

    1995-06-01

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

  6. Solar heat storage in phase change material

    SciTech Connect

    Phillips, H.J.

    1984-02-28

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

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

    E-print Network

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

    2006-01-01

    Assisted Heat Pump Heating System with Latent Heat Storage. In this system, solar energy is the major heat source for a heat pump, and the supplementary heat source is soil. The disagreement in time between the space heat load and heat collected by solar...

  8. Dynamics of heat storage in evapotranspiration estimate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the widely discussed reasons for a lack of surface energy balance closure when using eddy covariance is neglect of storage term elements. Storage as related to the surface energy balance refers to all heat stored below the observation level of eddies. It represents the sum of several componen...

  9. Advanced Heat Transfer and Thermal Storage Fluids

    SciTech Connect

    Moens, L.; Blake, D.

    2005-01-01

    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.

  10. Latent Heat Storage Materials and Systems: A Review

    Microsoft Academic Search

    S. D. Sharma; Kazunobu Sagara

    2005-01-01

    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

  11. Thermodynamic efficiency of pumped heat electricity storage.

    PubMed

    Thess, André

    2013-09-13

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

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

    Microsoft Academic Search

    1989-01-01

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

  13. Assessment of energy storage technologies and systems. Phase 1: Electric storage heating, storage air conditioning, and storage hot water heaters

    Microsoft Academic Search

    J. G. Asbury; R. Giese; S. Nelson; L. Akridge; P. Graf; K. Heitner

    1976-01-01

    The commercial feasibility of thermal energy storage (TES) in buildings is analyzed. TES applications examined include storage electric (resistance) heating, storage air conditioning, and storage hot water heating. A system model, SIMSTOR, is employed to simulate TES-related effects upon daily and annual utility load profiles and to compare utility fuel and capital cost savings with TES-system costs. Case-study analyses of

  14. Phase-change heat storage building panels

    SciTech Connect

    Korin, E.; Pasternak, D.; Rappaport, E.; Roy, A.S.; Wolf, D.

    1985-02-12

    The invention provides a phase change heat storage, light and temperature control building panel comprising a sealed housing having at least two walls transparent to visible light delimiting at least one intermediate space filled with a liquid-solid phase-change heat-storage material. The material is substantially transparent to visible light in solid and in liquid phase, adsorbs heat while melting, releases heat while solidifying and undergoes phase change in a temperature range of about 5/sup 0/-28/sup 0/ C. The invention also provides a method of day light and temperature control and night temperature control in dwelling units and plant enclosures utilizing the panels of the invention.

  15. Effects of reverse CO 2 acidification cycles, calcium supplementation, pH adjustment and chilled storage on physico-chemical and rennet coagulation properties of reconstituted low- and medium-heat skim milk powders

    Microsoft Academic Search

    Abdul H. Klandar; Dominique Chevalier-Lucia; Alain Lagaude

    2009-01-01

    The reversibility extent of one and two reverse CO2 acidification cycles on the physico-chemical and rennet coagulation properties of milks reconstituted from low- (LH) or medium- (MH) heat skim powder, enriched or not with calcium and pH adjusted or not was investigated. The ionized calcium concentration, buffering properties and average casein micelle size of untreated and CO2-treated milks were evaluated

  16. Heat Sponge: A Concept for Mass-Efficient Heat Storage

    NASA Technical Reports Server (NTRS)

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

    2008-01-01

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

  17. Position paper -- Waste storage tank heat removal

    SciTech Connect

    Stine, M.D.

    1995-01-03

    The purpose of this paper is to develop and document a position on the heat removal system to be used on the waste storage tanks currently being designed for the Multi-Function Waste Tank Facility (MWTF), project W-236A. The current preliminary design for the waste storage primary tank heat removal system consists of the following subsystems: (1) a once-through dome space ventilation system; (2) a recirculation dome space ventilation system; and (3) an annulus ventilation system. Recently completed and ongoing studies have evaluated alternative heat removal systems in an attempt to reduce system costs and to optimize heat removal capabilities. In addition, a thermal/heat transfer analysis is being performed that will provide assurance that the heat removal systems selected will be capable of removing the total primary tank design heat load of 1.25 MBtu/hr at an allowable operating temperature of 190 F. Although 200 F is the design temperature limit, 190 F has been selected as the maximum allowable operating temperature limit based on instrumentation sensitivity, instrumentation location sensitivity, and other factors. Seven options are discussed and recommendations are made.

  18. Design, construction and testing of a thermosyphon heat exchanger for medium temperature heat recovery in bakeries

    Microsoft Academic Search

    A. R. Lukitobudi; A. Akbarzadeh; P. W. Johnson; P. Hendy

    1995-01-01

    Using water as the working fluid, air-to-air heat exchangers using thermosyphon heat pipes were designed, constructed and tested under medium temperature (below 300°C) operating conditions. A heat exchanger test rig has been constructed and developed wherein the heated air is recycled to the counterflow heat exchanger. The lengths of both the evaporator section and the condenser section of the heat

  19. Residential Heat Storage Furnaces for Load Management - Design and Control

    Microsoft Academic Search

    R. H. S. Hardy; M. T. Sulatlsky; W. B. H. Cooke

    1980-01-01

    The use of thermal energy storage, or off-peak electric heating, to level the electric system load and improve the system load factor is described. A general introduction to the economic benefits of off-peak heating is given along with details of a heat storage furnace and controller designed for residential home heating on the Canadian Prairies.

  20. Distributed Generation with Heat Recovery and Storage

    SciTech Connect

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

    2005-07-29

    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.

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

    Microsoft Academic Search

    Hüseyin Benli

    2011-01-01

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

  2. Increasing Soil Heat Storage across Northern Eurasia

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

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

  3. Heat pipe effect in porous medium

    SciTech Connect

    Joseph, M.

    1992-12-01

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

  4. SELF-REGULATING SUPERNOVA HEATING IN INTERSTELLAR MEDIUM SIMULATIONS

    E-print Network

    Brandenburg, Axel

    with classical magnetohydrodynamic (MHD) forces. We model a relatively small box (of horizontal cross-section (0SELF-REGULATING SUPERNOVA HEATING IN INTERSTELLAR MEDIUM SIMULATIONS GRAEME R. SARSON1 , ANVAR-phase interstellar medium have been carried out, using a 3D

  5. General characteristics of thermochemical heat storage

    SciTech Connect

    Wentworth, W.

    1985-10-01

    The research and development on thermochemical heat storage have focused on systems which operate at either a low temperature (approx. 100-150/sup 0/C or 220-300/sup 0/F) or a high temperature (approx. 350-500/sup 0/C or 660-930/sup 0/F). The low temperature systems are intended primarily for heating and cooling buildings and can be operated with high efficiency, double-glazed flat plate solar collectors or slightly concentrating collectors such as parabolic troughs. The high temperature systems require a highly concentrated solar collector system such as the Power-Tower, where a field of heliostats (basically flat mirrors) focuses the sunlight onto a receiver mounted on a central tower. Alternatively, a smaller reflective surface in the shape of a parabaloid with a diameter of approx. 30 ft can be used to concentrate the solar energy to attain temperatures in excess of 1000/sup 0/C or 1830/sup 0/F. The high temperature storage systems are generally used for electrical power generation but could be used for process heat delivery. In order to generate power efficiently, a high temperature heat source is required. This need is based upon well-known thermodynamic principles, which will be explained in this paper.

  6. CalHEAT Research and Market Transformation Roadmap for Medium

    E-print Network

    California at Davis, University of

    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

  7. Thermal storage technologies for solar industrial process heat applications

    NASA Technical Reports Server (NTRS)

    Gordon, L. H.

    1979-01-01

    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.

  8. Distributed Generation with Heat Recovery and Storage

    SciTech Connect

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

    2006-06-16

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

  9. Waste Heat Recovery Using a Circulating Heat Medium Loop

    E-print Network

    Manning, E., Jr.

    1981-01-01

    , and the coker; the heat is used to reboil a butylenes splitter column and to preheat boiler feed Water. The heat that is recovered is equivalent to some 660 B/D of fuel: at an illustrative fuel value of say $30 per barrel, the value of the recovered heat is $20...

  10. 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

  11. Thermal control system using heat pump and thermal storage

    Microsoft Academic Search

    Shunsuke Hosokawa; Akira Iwasaki; Yoshiyuki Abe; Masakuni Kawada; Isao Kudo

    1988-01-01

    The use of a heat pump augmented radiator to control radiator temperature in a spacecraft's thermal control system is examined. Also, the combination of thermal storage and a heat pump to reduce radiator size and weight is considered. An experimental heat pump augmented radiator system using thermal storage is constructed and tested. The results show that the system is effective

  12. COSMIC RAY HEATING OF THE WARM IONIZED MEDIUM

    SciTech Connect

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

    2013-04-10

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

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

    NASA Technical Reports Server (NTRS)

    Saha, H.

    1977-01-01

    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.

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

    Microsoft Academic Search

    Satoru Okamoto

    2006-01-01

    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

  15. Thermal Storage and Advanced Heat Transfer Fluids (Fact Sheet)

    SciTech Connect

    Not Available

    2010-08-01

    Fact sheet describing NREL CSP Program capabilities in the area of thermal storage and advanced heat transfer fluids: measuring thermophysical properties, measuring fluid flow and heat transfer, and simulating flow of thermal energy and fluid.

  16. THERMOCHEMICAL HEAT STORAGE FOR CONCENTRATED SOLAR POWER

    SciTech Connect

    PROJECT STAFF

    2011-10-31

    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

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

    NASA Technical Reports Server (NTRS)

    Saha, H.

    1981-01-01

    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.

  18. Waste Heat Recovery Using a Circulating Heat Medium Loop 

    E-print Network

    Manning, E., Jr.

    1981-01-01

    As energy costs continue to increase, one must be willing to accept greater complexities in heat recovery systems. The days of being satisfied with only simple hot product to cold feed exchange, restricted to the plot boundaries of each unit, are a...

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

    E-print Network

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

    2006-01-01

    ICEBO2006, Shenzhen, China Re newable Energy Resources and a Greener Future Vol.VIII-2-3 Experimental Research on Solar Assisted Heat Pump Heating System with Latent Heat Storage Zongwei Han Maoyu Zheng Wei Liu Fang Wang... of the tank is very low and then the tank is shut off at night or cloudy days during heating period. 4. PERFORMANCE ANALYSIS OF SYSTEM OPERATION Heating experiment has been done for 4 months from Nov. 15th, 2004 to Mar., 31st, 2005 in order to find...

  20. HEAT STORAGE AND ADVECTION IN THE NORTH PACIFIC OCEAN

    E-print Network

    Luther, Douglas S.

    HEAT STORAGE AND ADVECTION IN THE NORTH PACIFIC OCEAN A DISSERTATION SUBMITTED TO THE GRADUATE maintaining the seasonal heat storage in the 0 to 250 meter surface layer of the North Pacific Ocean. Approximately 140,000 bathy- thermograph observations taken in the Pacific Ocean from 10° South latitude to 70

  1. A solar air collector with integrated latent heat thermal storage

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

  2. Experimental improvements of heat transfer in a latent heat thermal energy storage unit with embedded heat sources

    Microsoft Academic Search

    M. Lacroix; T. Duong

    1998-01-01

    An experimental study was conducted in order to improve the heat transfer in a single layer latent heat thermal energy storage unit with embedded electrical heat sources. This study is motivated by the need to increase the performance of a more complex multi-layer latent heat thermal energy storage system used for smoothing daily electrical load profiles. In the first part,

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

    SciTech Connect

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

    1982-01-01

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

  4. Method and apparatus for inoculating crystallization seeds into a liquid latent heat storage substance

    SciTech Connect

    Lindner, F.; Scheunemann, K.

    1984-07-24

    A method and apparatus for inoculating a liquid latent heat storage substance of the type convertible to the solid state on cooling is disclosed. A portion of the substance is caused to crystallize on a cooled active surface, immersed in the substance and preferably vertically arranged, whereupon the active surface is heated to fuse-off the formed crystals to release them into the liquid portion of the storage substance to thus form inoculation seeds on which further crystallization of the storage substance takes place on withdrawal of heat from same. In one described embodiment, a pair of active surfaces is provided by using a Peltier element operating with a DC source having selectively reversible polarity whereby one surface is cooled down while the other is heated and vice versa, depending on the instant polarity of the DC source. In another embodiment, the active surface is alternately heated and cooled by heat carrier medium of a heat pump circulation system drawn from the respective sections of the system in alternating fashion. Due to the formation of crystallization seeds from the heat storage substance, problems normally associated with the use of a foreign inoculation substance are avoided.

  5. Radiant heat transfer from storage casks to the environment

    Microsoft Academic Search

    R W Carlson; J Hovingh; G R Thomas

    1999-01-01

    A spent fuel storage cask must efficiently transfer the heat released by the fuel assemblies through the cask walls to the environment. This heat must be transferred through passive means, limiting the energy transfer mechanisms from the cask to natural convection and radiation heat transfer.. Natural convection is essentially independent of the characteristics of the array of casks, provided there

  6. Heat-pump cool storage in a clathrate of freon

    NASA Astrophysics Data System (ADS)

    Tomlinson, J. J.

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

  7. Heating of the intergalactic medium due to structure formation

    E-print Network

    Biman Nath; Joseph Silk

    2001-07-20

    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 $10^{-6}$.

  8. Thermal storage device

    SciTech Connect

    Schroder, J.

    1982-04-13

    The increase in volume of a heat storage medium comprising water or a first eutectic mixture of water and a salt hydrate, when such storage medium passes from the liquid to the solid state, is prevented from occurring by adding 1 to 6% by volume of a second water-salt hydrate eutectic having a lower freezing point to the storage medium.

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

    Microsoft Academic Search

    S. M. Hasnain

    1998-01-01

    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

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

    Microsoft Academic Search

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

    1997-01-01

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

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

    Microsoft Academic Search

    Maryam Gharebaghi; I. Sezai

    2008-01-01

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

  12. Heating of the intracluster medium by quasar outflows

    NASA Astrophysics Data System (ADS)

    Nath, Biman B.; Roychowdhury, Suparna

    2002-06-01

    We study the possibility of quasar outflows in clusters and groups of galaxies heating the intracluster gas in order to explain the recent observation of excess entropy in this gas. We use the extended Press-Schechter formalism to estimate the number of quasars that become members of a group or cluster of a given mass and formation epoch. We also estimate the fraction of mechanical energy in the outflows that is imparted to the surrounding medium as a function of the density and temperature of this gas. We finally calculate the total amount of non-gravitational heating from such outflows as a function of the cluster potential and formation epoch. We show that outflows from broad absorption line and radio-loud quasars can provide the required amount of heating of the intracluster gas. We find that in this scenario most of the heating takes place at z~1-4, and that this `pre-heating' epoch is at lower redshift for lower-mass clusters.

  13. Heat insulating device for low temperature liquified gas storage tanks

    Microsoft Academic Search

    T. Okamoto; T. Nishimoto; K. Sawada; K. Hayakawa; T. Kurihara

    1977-01-01

    The insulating construction for a low temperature liquified gas storage tank consists of a plurality of heat insulating blocks or plates of rigid foam, each covered with a gas-tight sheet bonded thereto and each bolted at its approximate center to the outer wall of the tank. The joints between adjacent plates are filled with a heat insulating material and a

  14. Characterization and Evaluation of a Mass Efficient Heat Storage Device.

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

    The heat sponge is a device for mass-efficient storage of heat. It was developed to be incorporated in the substructure of a reentry or hypersonic vehicle to reduce thermal protection system requirements. The heat sponge consists of a liquid-vapor mixture contained within a number of miniature pressure vessels that can be embedded within a variety of different types of structures. As temperature is increased, pressure in the miniature pressure vessels also increases so that heat absorbed through vaporization of the liquid is spread over a relatively large temperature range. Using water as a working fluid, the heat storage capacity of the liquid-vapor mixture is many times higher than that of typical structural materials and is well above that of common phase change materials over the temperature range of 660oR to 1160oR. Prototype heat sponges were fabricated and characterized. These heat sponges consisted of 1.0 inch diameter hollow stainless steel spheres with a wall thickness of 0.020 inches which had varying percentages of their interior volumes filled with water. An apparatus to measure the heat stored in these prototype heat sponges was designed, fabricated, and verified. The heat storage capacity calculated from measured temperature histories is compared to numerical predictions.

  15. Microencapsulated Phase-Change Materials For Storage Of Heat

    NASA Technical Reports Server (NTRS)

    Colvin, David P.

    1989-01-01

    Report describes research on engineering issues related to storage and transport of heat in slurries containing phase-change materials in microscopic capsules. Specific goal of project to develop lightweight, compact, heat-management systems used safely in inhabited areas of spacecraft. Further development of obvious potential of technology expected to lead to commercialization and use in aircraft, electronic equipment, machinery, industrial processes, and other sytems in which requirements for management of heat compete with severe restrictions on weight or volume.

  16. Heat-pumped thermochemical energy-storage system

    Microsoft Academic Search

    Nix

    1983-01-01

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

  17. A heat-pumped thermochemical energy storage system

    Microsoft Academic Search

    Nix

    1983-01-01

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

  18. Heating of the intracluster medium by quasar outflows

    E-print Network

    Biman Nath; Suparna Roychowdhury

    2002-02-10

    We study the possibility of quasar outflows in clusters and groups of galaxies heating the intracluster gas in order to explain the recent observation of excess entropy in this gas. We use the extended Press-Schechter formalism to estimate the number of quasars that become members of a group of cluster of a given mass and formation epoch. We also estimate the fraction of mechanical energy in the outflows that is imparted to the surrounding medium as a function of the density and temperature of this gas. We finally calculate the total amount of non-gravitational heating from such outflows as a function of the cluster potential and formation epoch. We show that outflows from broad absorption line (BAL) and radio loud quasars can provide the required amount of heating of the intracluster gas. We find that in this scenario most of the heating takes place at $z \\sim 1\\hbox{--}4$, and that this ``preheating'' epoch is at lower redshift for lower mass clusters.

  19. Heating of the intracluster medium by quasar outflows

    E-print Network

    Nath, B B; Nath, Biman; Roychowdhury, Suparna

    2002-01-01

    We study the possibility of quasar outflows in clusters and groups of galaxies heating the intracluster gas in order to explain the recent observation of excess entropy in this gas. We use the extended Press-Schechter formalism to estimate the number of quasars that become members of a group of cluster of a given mass and formation epoch. We also estimate the fraction of mechanical energy in the outflows that is imparted to the surrounding medium as a function of the density and temperature of this gas. We finally calculate the total amount of non-gravitational heating from such outflows as a function of the cluster potential and formation epoch. We show that outflows from broad absorption line (BAL) and radio loud quasars can provide the required amount of heating of the intracluster gas. We find that in this scenario most of the heating takes place at $z \\sim 1\\hbox{--}4$, and that this ``preheating'' epoch is at lower redshift for lower mass clusters.

  20. Residential application of the Rutgers system for solar heating of greenhouses. [Flooded subfloor heat storage

    Microsoft Academic Search

    1980-01-01

    An important feature of the Rutgers system for solar heating of greenhouses is a flooded subfloor which serves as a massive storage and enables the entire floor surface to act as the primary heat exchanger. Preliminary studies indicate that adapting this concept to a residential space heating system would enable the solar system to operate at low temperatures, about 25

  1. MEDIUM AND LONG-TERM STORAGE OF RUBUS GERMPLASM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The United States Department of Agriculture, Agricultural Research Service, National Clonal Germplasm Repository at Corvallis, Oregon, preserves genetic resources for Rubus. The in vitro collection includes about 200 accessions. In vitro cold storage of these accessions is at 4°C with 12 h of low l...

  2. Integrated heat pipe-thermal storage system performance evaluation

    NASA Astrophysics Data System (ADS)

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

    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.

  3. Integrated heat pipe-thermal storage system performance evaluation

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    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.

  4. Low temperature heat storage with phase change materials

    Microsoft Academic Search

    1980-01-01

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

  5. Heat transfer effects in compressed air energy storage

    Microsoft Academic Search

    K. G. Vosburgh; P. G. Kosky

    1977-01-01

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

  6. Do Heat Waves have an Impact on Terrestrial Water Storage?

    NASA Astrophysics Data System (ADS)

    Brena-Naranjo, A.; Teuling, R.; Pedrozo-Acuña, A.

    2014-12-01

    Recent works have investigated the impact of heat waves on the surface energy and carbon balance. However, less attention has been given to the impacts on terrestrial hydrology. During the summer of 2010, the occurrence of an exceptional heat wave affected severely the Northern Hemisphere. The extension (more than 2 million km2) and severity of this extreme event caused substantial ecosystem damage (more than 1 million ha of forest fires), economic and human losses (~500 billion USD and more than 17 million of indirect deaths, respectively). This work investigates for the first time the impacts of the 2010 summer heat wave on terrestrial water storage. Our study area comprises three different regions where air temperature records were established or almost established during the summer: Western Russia, the Middle East and Eastern Sahel. Anomalies of terrestrial water storage derived from the Gravity Recovery and Climate Experiment (GRACE) were used to infer water storage deficits during the 2003-2013 period. Our analysis shows that Russia experienced the most severe water storage decline, followed by the Middle East, whereas Eastern Sahel was not significantly affected. The impact of the heat wave was spatially uniform in Russia but highly variable in the Middle East, with the Northern part substantially more affected than the Southern region. Lag times between maxima air temperatures and lower water storage deficits for Russia and the Middle East were approximately two and seven months, respectively. The results suggest that the response of terrestrial water storage to heat waves is stronger in energy-limited environments than in water-limited regions. Such differences in the magnitude and timing between meteorological and hydrological extremes can be explained by the propagation time between atmospheric water demand and natural or anthropogenic sources of water storage.

  7. Thermal energy storage technologies for heating and cooling applications

    NASA Astrophysics Data System (ADS)

    Tomlinson, John J.

    1990-12-01

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

  8. Performance of phase change materials for heat storage thermoelectric harvesting

    NASA Astrophysics Data System (ADS)

    Kiziroglou, M. E.; Elefsiniotis, A.; Wright, S. W.; Toh, T. T.; Mitcheson, P. D.; Becker, Th.; Yeatman, E. M.

    2013-11-01

    Heat storage energy harvesting devices have promise as independent power sources for wireless aircraft sensors. These generate energy from the temperature variation in time during flight. Previously reported devices use the phase change of water for heat storage, hence restricting applicability to instances with ground temperature above 0 °C. Here, we examine the use of alternative phase change materials (PCMs). A recently introduced numerical model is extended to include phase change inhomogeneity, and a PCM characterization method is proposed. A prototype device is presented, and two cases with phase changes at approximately -9.5 °C and +9.5 °C are studied.

  9. A ground-coupled storage heat pump system with waste heat recovery

    Microsoft Academic Search

    D. C. Drown; K. R. D. Braven; T. P. Kast

    1992-01-01

    This paper reports on an experimental single-family residence that was constructed to demonstrate integration of waste heat recovery and seasonal energy storage using both a ventilating and a ground-coupled heat pump. Called the Idaho energy Conservation Technology House, it combines superinsulated home construction with a ventilating hot water heater and a ground coupled water-to-water heat pump system. The ground heat

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

    Microsoft Academic Search

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

    1991-01-01

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

  11. Macro-encapsulation of heat storage phase-change materials for use in residential buildings. First quarterly progress report, September 29December 29, 1976

    Microsoft Academic Search

    A. C. Kott; H. E. Rossow

    1977-01-01

    Objectives are to assess the feasibility of macro-encapsulated PCM's for residential solar systems, to develop and evaluate such materials. Five PCM's have been selected from encapsulation studies. Encapsulated storage media were evaluated theoretically in storage beds with air and water as the heat transfer medium. Cylindrical, tetrahedral, and pillow shapes are being evaluated for the encapsulated PCM. Encapsulant materials under

  12. 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

    Zhongliang Liu; Zengyi Wang; Chongfang Ma

    2006-01-01

    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,

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

    Microsoft Academic Search

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

    2002-01-01

    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

  14. Heat pipe solar receiver with thermal energy storage

    NASA Technical Reports Server (NTRS)

    Zimmerman, W. F.

    1981-01-01

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

  15. Earth's Energy Imbalance and Ocean Heat Storage

    NASA Astrophysics Data System (ADS)

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

    2006-12-01

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

  16. Earth storage of solar heat. Final report

    SciTech Connect

    Garst, P.

    1982-04-19

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-11-01

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

  18. Thermal performance and heat transport in aquifer thermal energy storage

    NASA Astrophysics Data System (ADS)

    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

    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.

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

    Microsoft Academic Search

    Kamil Kaygusuz; Ahmet Sari

    2005-01-01

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

  20. Integrated heat pipe-thermal storage system performance evaluation

    Microsoft Academic Search

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

    1987-01-01

    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

  1. Thermal storage for industrial process and reject heat

    Microsoft Academic Search

    R. A. Duscha; W. J. Masica

    1978-01-01

    Industrial production uses about 40% 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. Results of study contracts awarded by the Department of Energy (DOE) and managed

  2. Heat storage system utilizing phase change materials government rights

    Microsoft Academic Search

    Salyer; Ival O

    2000-01-01

    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

  3. Kerava solar village - a solar assisted heat pump system with long-term heat storage

    Microsoft Academic Search

    R. Maekinen; P. D. Lund

    1983-01-01

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

  4. Residential application of the Rutgers system for solar heating of greenhouses. [Flooded subfloor heat storage

    SciTech Connect

    Mears, D.R.

    1980-01-01

    An important feature of the Rutgers system for solar heating of greenhouses is a flooded subfloor which serves as a massive storage and enables the entire floor surface to act as the primary heat exchanger. Preliminary studies indicate that adapting this concept to a residential space heating system would enable the solar system to operate at low temperatures, about 25 to 30/sup 0/C facilitating the use of simple and low-cost solar collection systems. A 125-year old residence is being retrofit with a 2-story addition with a flooded subfloor and a lean-to style greenhouse also with a flooded subfloor storage. A wooded stove with a water heating coil supplements the solar system and the pre-existing residential heating system is the final backup. Since the system became partially operational in early February, all space heating needs have been met by passive gain from the greenhouse and the wood stove.

  5. Heat-pumped thermochemical energy-storage system

    SciTech Connect

    Nix, R.G.

    1983-04-01

    This paper investigates the use of chemical heat-pumped energy storage systems for supplying 0.101 and 0.448 MPa steam for industrial use. The solar collectors are parabolic troughs. The working fluid for the chemical heat pump system is water, which is added to and removed from NaOH solutions to release and absorb energy. If waste heat is available, it can be heat-pumped by the NaOH system to provide 0.101 MPa (14.7 psia) steam with about 55% of the solar energy input of a conventional solar system with hot oil working fluid. If 0.448 MPa (65 psia) steam is needed, the NaOH system requires multistage heat pumping. In this case, the hot oil system would require about 13% less solar energy input than does the NaOH system.

  6. A heat-pumped thermochemical energy storage system

    SciTech Connect

    Nix, R.G.

    1983-08-01

    This paper investigates the use of chemical heat-pumped energy storage systems for supplying 0.101 and 0.448 MPa steam for industrial use. The solar collectors are parabolic troughs. The working fluid for the chemical heat pump system is water, which is added to and removed from NaOH solutions to release and absorb energy. If waste heat is available, it can be heat-pumped by the NaOH system to provide 0.101 MPa (14.7 psia) steam with about 55% of the solar energy input of a conventional solar system with hot oil working fluid. If 0.448 MPa (65 psia) steam is needed, the NaOH system requires multistage heat pumping. In this case, the hot oil system would require about 13% less solar energy input than does the NaOH system.

  7. Optimal capacity planning of heat pump/thermal storage system used for district heating and cooling

    SciTech Connect

    Ito, Koichi; Shiba, Takashi [Univ. of Osaka Prefecture, Sakai, Osaka (Japan)

    1995-12-31

    An optimal capacity planning method is proposed for heat pump/thermal storage system used for district heating and cooling. Equipment capacities and utility maximum demands are determined so as to minimize the annual total cost in consideration of the system`s operational strategy for the hourly varying energy demand in a year. The operational problem of the heat pump/thermal storage system is large scale one and a numerical method is proposed to solve the problem by using sensitivity analysis method. In a numerical study for district heating and cooling, seasonal utilization is investigated for thermal storage tanks from the economic viewpoint. From the result obtained, it is ascertained that the proposed method is a useful tool for the fundamental system`s planning problem.

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

    E-print Network

    Saxe, Shoshanna Dawn

    2009-01-01

    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 ...

  9. Methanol-based heat pump for solar heating, cooling, and storage. Phase III. Final report

    Microsoft Academic Search

    P. OD Offenhartz; T. V. Rye; R. E. Malsberger; D. Schwartz

    1981-01-01

    The reaction of CHâOH vapor with solid (pellet) CaClâ to form the solid phase compound CaCllâ . 2CHâOH can be used as the basis of a combined solar heat pump\\/thermal energy storage system. Such a system is capable of storing heat indefinitely at ambient temperature, and can be used for space and domestic hot water heating, and for air conditioning

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

    PubMed

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

    2014-04-01

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

  11. Heat pipe based cold energy storage systems for datacenter energy conservation

    Microsoft Academic Search

    Randeep Singh; Masataka Mochizuki; Koichi Mashiko; Thang Nguyen

    2011-01-01

    In the present paper, design and economics of the novel type of thermal control system for datacenter using heat pipe based cold energy storage 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 kW. Basically, the cold

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

    Microsoft Academic Search

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

    2010-01-01

    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

  13. Computational heat transfer modeling of thermal energy storage canisters

    NASA Astrophysics Data System (ADS)

    Sokolov, Pavel Alexandrovich

    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 the temperature distributions and the void behavior in the canisters. These in turn can be used for the canister thermal stress analyses. The emphasis in the development of the code is made on accurate descriptions of the solid-liquid phase change process, void dynamics and heat transfer, convective and radiative heat transfer modes in the PCM. The capabilities of the code include computations of three dimensional and axisymmetric heat transfer and fluid mechanics phenomena inside the canisters. The code validation has been made based on the results of ground tests and two Thermal Energy Storage flight experiments, TES-1 and TES-2. The validated code has been used for canister analyses. The following features have been examined: (1) the location of "hot spots" in the canister, especially canister walls; (2) the void location and heat transfer predictions; (3) the importance of radiative and convective heat transfer modes in the void and liquid PCM; and (4) influence of three-dimensional versus axisymmetric boundary conditions on the canister performance. The code could be also used to analyze canisters of geometries different from cylindrical and other phenomena involving solid-liquid phase change.

  14. Thermal energy storage for building heating and cooling applications. Quarterly progress report, April--June 1976

    Microsoft Academic Search

    H. W. Hoffman; R. J. Kedl

    1976-01-01

    This is the first in a series of quarterly progress reports covering activities at ORNL to develop thermal energy storage (TES) technology applicable to building heating and cooling. Studies to be carried out will emphasize latent heat storage in that sensible heat storage is held to be an essentially existing technology. Development of a time-dependent analytical model of a TES

  15. Active heat exchange system development for latent heat thermal energy storage

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

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

  16. Fluid Latent Heat Storage Material Using Ethanol Water Mixture

    NASA Astrophysics Data System (ADS)

    Ohkubo, Hidetoshi; Yasunari, Yuki

    Ethanol water mixture has a liquidus line ( or crystallizing line) and a solidus line (or melting line) that are separated, and therefore it can have both liquid and solid phases existing together. With advances in low temperature technology in recent days, ethanol water mixture is attaching more and more attention as an environment-friendly coolant or as a thermal storage material. In the present study, we observed the crystallization process in the mixture and carried out experiments to evaluate fluidity of the mixture, with the objective of utilizing an ethanol water mixture as a coolant or a thermal energy storage material. Crystal formation and growing process within a minute droplet of a binary mixture was modeled. As a result, we found a novel method to produce a fluid latent heat storage material continuously and an apparent coefficient of viscosity show that rotational speed and solid phase fraction have a strong effect on the fluidity of the mixture.

  17. Heat storage and distribution inside passive-solar buildings

    SciTech Connect

    Balcomb, J.D.

    1983-01-01

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

  18. (Thermal energy storage technologies for heating and cooling applications)

    SciTech Connect

    Tomlinson, J.J.

    1990-12-19

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

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

    E-print Network

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

    2006-01-01

    Jan-Olof Dalenback Associate Professor Graduate student Professor University of Shanghai for Sci. and Tech University of Shanghai for Sci. and Tech Chalmers University of Technology Shanghai & China Shanghai & China Gothenberg & Sweden... significantly. (5) When the ratio of volume of seasonal storage tank to collector areas is 2~3, the system performance is optimal for many areas of China. REFERENCE [1] Jan-Olof Dalenback, Central solar heating plant with seasonal storage...

  20. HEAT STORAGE BY PHASE CHANGING MATERIALS AND THERMOECONOMICS

    Microsoft Academic Search

    Yasar Demirel

    Heat storage systems by phase changing materials (PCM) need to identify the performance limits and optimize processes and\\u000a cycles with thermodynamic analysis. Such an analysis consists of concepts like thermoeconomics, entropy generation minimization,\\u000a and the extended exergy accounting, which calculates resource-based value of a commodity by establishing a comprehensive relation\\u000a between exergy and economic values. Some other concepts are the

  1. A thermochemical energy storage system and heat pump

    Microsoft Academic Search

    M. T. Howerton

    1978-01-01

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

  2. Experimental assessment of heat storage properties and heat transfer characteristics of a phase change material slurry for air conditioning applications

    Microsoft Academic Search

    Bogdan M. Diaconu; Szabolcs Varga; Armando C. Oliveira

    2010-01-01

    A new microencapsulated phase change material slurry based on microencapsulated Rubitherm RT6 at high concentration (45% w\\/w) was tested. Some heat storage properties and heat transfer characteristics have been experimentally investigated in order to assess its suitability for the integration into a low temperature heat storage system for solar air conditioning applications. DSC tests were conducted to evaluate the cold

  3. Assessing a novel room-temperature RNA storage medium for compatibility in microarray gene expression analysis.

    PubMed

    Hernandez, Gilberto E; Mondala, Tony S; Head, Steven R

    2009-08-01

    RNA integrity is a critical factor in obtaining meaningful gene expression data. Current methodologies rely on maintaining samples in cold environments during collection, transport, processing, and storage procedures, which are also extremely time-sensitive. Several RNA storage products are commercially available to help prevent degradation during the handling and storage steps; however, samples must be kept cold for optimal protection. We have evaluated a novel RNA storage medium based on anhydrobiosis for stabilizing and protecting samples from degradation at room temperature that are intended for use in microarray analysis. Samples were stored dry at room temperature for various time periods to assess any degradation or loss of activity as compared with frozen control samples. Recovered samples were used directly for analysis without further purification and exhibited no interference or inhibition in downstream applications. Comparison of gene expression profiles indicate no significant differences between freezer-stored control samples and those kept at room temperature protected in the RNA storage medium. The quality of recovered RNA was confirmed using spectrophotometry and Bioanalyzer analysis and was identical to control samples. The ability to stabilize RNA samples at ambient temperatures for extended time periods will have tremendous use, particularly for sample shipment to core facilities. PMID:19737132

  4. Thermal energy storage – overview and specific insight into nitrate salts for sensible and latent heat storage

    PubMed Central

    Bauer, Thomas; Martin, Claudia; Eck, Markus; Wörner, Antje

    2015-01-01

    Summary Thermal energy storage (TES) is capable to reduce the demand of conventional energy sources for two reasons: First, they prevent the mismatch between the energy supply and the power demand when generating electricity from renewable energy sources. Second, utilization of waste heat in industrial processes by thermal energy storage reduces the final energy consumption. This review focuses mainly on material aspects of alkali nitrate salts. They include thermal properties, thermal decomposition processes as well as a new method to develop optimized salt systems. PMID:26199853

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

    Microsoft Academic Search

    Nakhamkin

    1988-01-01

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

  6. Thermal energy storage in phase change materials for heating applications

    SciTech Connect

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

    1995-12-31

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

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

    Microsoft Academic Search

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

    1999-01-01

    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

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

    Microsoft Academic Search

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

    1995-01-01

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

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

    Microsoft Academic Search

    Fang Wang; Maoyu Zheng; Zhongjian Li

    2008-01-01

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

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

    E-print Network

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

    2006-01-01

    , operating modes and weather conditions. The results show that 1) for most areas of China, the solar systems with seasonal storage can save energy; 2) for areas with cold winter and hot summer, it is suitable to store heat from summer to winter and store...

  11. Numerical analysis of melting with constant heat flux heating in a thermal energy storage system

    Microsoft Academic Search

    Zhongliang Liu; Chongfang Ma

    2002-01-01

    Melting in a finite slab with a second kind boundary condition is studied numerically in order to simulate the charging process of a thermal energy storage system. A dimensionless model is given, from which it is concluded that the main factors that influence the melting process are the dimensionless heating flux, the modified Stefan number, the relative thermal diffusivity and

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

    Microsoft Academic Search

    Burkhard Sanner; Constantine Karytsas; Dimitrios Mendrinos; Ladislaus Rybach

    2003-01-01

    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

  13. Quantum storage and cloning of light states in EIT-like medium

    E-print Network

    A. P. Alodjants; S. M. Arakelian

    2006-09-25

    In the paper we consider a new approach for storage and cloning of quantum information by three level atomic (molecular) systems in the presence of the electromagnetically induced transparency (EIT) effect. For that, the various schemes of transformation into the bright and dark polaritons for quantum states of optical field in the medium are proposed. Physical conditions of realization of quantum nondemolition (QND) storage of quantum optical state are formulated for the first time. We have shown that the best storage and cloning of can be achieved with the atomic ensemble in the Bose-Einstein condensation state. We discuss stimulated Raman two-color photoassociation for experimental realization of the schemes under consideration.

  14. A 'two-tank' seasonal storage concept for solar space heating of buildings

    Microsoft Academic Search

    B. K. Cha; D. W. Connor; R. O. Mueller

    1981-01-01

    This paper presents an analysis of a novel 'two-tank' water storage system, consisting of a large primary water tank for seasonal storage of solar energy plus a much smaller secondary water tank for storage of solar energy collected during the heating season. The system offers the advantages of high collection efficiency during the early stages of the heating season, a

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

    PubMed Central

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

    2014-01-01

    Objective There is evidence indicating that pomegranate juice contains many of the essential properties necessary to retain cell viability and cell proliferation. These properties indicate that pomegranate juice is a suitable storage medium for avulsed teeth. However, this idea has not yet been tested. In this study, the capacity of pomegranate juice (PJ) as a storage medium for retaining avulsed teeth was evaluated. Materials and Methods: PDL fibroblasts were obtained from healthy human premolars and cultured in Dulbecco’s Modified Eagle’s Medium (DMEM). Cultured cells were subjected to different concentrations of pomegranate juice (PJ), 1% Hank’s balanced salt solution (HBSS) and tap water for 1, 3, 6 and 24 hours. PDL cell viability was assessed by the neutral red uptake assay. Results: The results indicated that 7.5% PJ was the most effective solution for maintaining PDL cell viability amongst all the experimental solution’s and time intervals (P<0.05). The results also showed that 1% PJ was as effective as HBSS for maintaining PDL cell viability. The amount of cell viability increased with increasing concentration of PJ at all time intervals (P<0.001). This effect is suggestive of the proliferative potential of PJ solution. Conclusion: In conclusion, PJ can be recommended as a suitable transport medium for avulsed teeth. PMID:24910699

  16. Heat storage in horses during submaximal exercise before and after humid heat acclimation.

    PubMed

    Geor, R J; McCutcheon, L J; Ecker, G L; Lindinger, M I

    2000-12-01

    The effect of humid heat acclimation on thermoregulatory responses to humid and dry exercise-heat stress was studied in six exercise-trained Thoroughbred horses. Horses were heat acclimated by performing moderate-intensity exercise for 21 days in heat and humidity (HH) [34.2-35.7 degrees C; 84-86% relative humidity (RH); wet bulb globe temperature (WBGT) index approximately 32 degrees C]. Horses completed exercise tests at 50% of peak O(2) uptake until a pulmonary arterial temperature (T(pa)) of 41.5 degrees C was attained in cool dry (CD) (20-21.5 degrees C; 45-50% RH; WBGT approximately 16 degrees C), hot dry (HD 0) [32-34 degrees C room temperature (RT); 45-55% RH; WBGT approximately 25 degrees C], and HH conditions (HH 0), and during the second hour of HH on days 3, 7, 14, and 21, and in HD on the 18th day (HD 18) of heat acclimation. The ratios of required evaporative capacity to maximal evaporative capacity of the environment (E(req)/E(max)) for CD, HD, and HH were approximately 1.2, 1.6, and 2.5, respectively. Preexercise T(pa) and rectal temperature were approximately 0.5 degrees C lower (P < 0. 05) on days 7, 14, and 21 compared with day 0. With exercise in HH, there was no effect of heat acclimation on the rate of rise in T(pa) (and therefore exercise duration) nor the rate of heat storage. In contrast, exercise duration was longer, rate of rise in T(pa) was significantly slower, and rate of heat storage was decreased on HD 18 compared with HD 0. It was concluded that, during uncompensable heat stress in horses, heat acclimation provided modest heat strain advantages when E(req)/E(max) was approximately 1.6, but at higher E(req)/E(max) no advantages were observed. PMID:11090580

  17. Thermal storage for industrial process and reject heat

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

    Industrial production uses about 40% 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. Results of study contracts awarded by the Department of Energy (DOE) and managed by the NASA Lewis Research Center have identified three especially significant industries where high temperature TES appears attractive - paper and pulp, iron and steel, and cement. Potential annual fuel savings with large scale implementation of near-term TES systems for these three industries is nearly 9 million bbl of oil.

  18. Thermal storage for industrial process and reject heat

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

    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.

  19. Medium voltage motor harmonic heating, torques and voltage stress when applied on VFDs

    Microsoft Academic Search

    Frank A. DeWinter; Bin Wu

    1996-01-01

    The increase in the application of medium voltage variable frequency drives to AC motors has raised concerns regarding the effects the drives have on the motors. Most of the published data available is for low voltage motors and drives, which are not necessarily accurate for the medium voltage applications. We address the harmonic heating, torques and voltage stress that are

  20. Patchy blazar heating: diversifying the thermal history of the intergalactic medium

    E-print Network

    Lamberts, Astrid; Pfrommer, Christoph; Puchwein, Ewald; Broderich, Avery E; Shalaby, Mohamad

    2015-01-01

    TeV-blazars potentially heat the intergalactic medium (IGM) as their gamma rays interact with photons of the extragalactic background light to produce electron-positron pairs, which lose their kinetic energy to the surrounding medium through plasma instabilities. This results in a heating mechanism that is only weakly sensitive to the local density, and therefore approximately spatially uniform, naturally producing an inverted temperature-density relation in underdense regions. In this paper we go beyond the approximation of uniform heating and quantify the heating rate fluctuations due to the clustered distribution of blazars and how this impacts on the thermal history of the IGM. We analytically compute a filtering function that relates the heating rate fluctuations to the underlying dark matter density field. We implement it in the cosmological code GADGET-3 and perform large scale simulations to determine the impact of inhomogeneous heating. We show that, because of blazar clustering, blazar heating is in...

  1. AQUIFER THERMAL ENERGY STORAGE SYSTEM FOR COOLING AND HEATING OF ÇUKUROVA UNIVERSITY BALCALI HOSPITAL

    Microsoft Academic Search

    Halime Paksoy; Olof Andersson

    An Underground Thermal Energy Storage (UTES) system that will conserve a considerable part of the oil and electricity being used in the heating and cooling system of the Balcali Hospital in Adana, Turkey is being planned. The system uses an aquifer for seasonal storage. Two alternatives have been studied, one without a heat pump and the other with a heat

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

    Microsoft Academic Search

    A. Sari; A. Karaipekli; K. Kaygusuz

    2008-01-01

    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

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

    Microsoft Academic Search

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

    1988-01-01

    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

  4. Method for compressing and heating a heating medium to be externally supplied to an engine while using the energy available in the hot exhaust gases of the engine

    Microsoft Academic Search

    Carlquist

    1985-01-01

    In a method for compressing and heating a heating medium to be externally supplied to an engine, while using the energy available in the hot exhaust gases of the engine, the exhaust gases are caused to expand in at least two expansion stages to emit energy for compressing the heating medium in at least two compression stages, heat is transmitted

  5. Monitoring changes in upper ocean heat storage from satellites

    NASA Technical Reports Server (NTRS)

    Miller, J. R.

    1978-01-01

    A one-dimensional model of the upper ocean mixed-layer was developed to determine how the parameters which can be measured from satellites affect the development of the layer. The results show that the form of the dissipation term is important in achieving cyclic annual states, that the layer deepending rate depends on the averaging period for the surface heat flux and wind stress, that wind direction, as well as magnitude, can affect the deepening rate and that horizontal advective effects cannot simply be superimposed on the model results. An algorithm is given which uses satellite derived wind stress and sea surface temperature data to predict real time changes in upper ocean heat storage during the cooling seasons.

  6. Solar heat pump

    NASA Astrophysics Data System (ADS)

    Hermanson, R.

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

  7. Modelling of a two-tank seasonal storage system for solar space heating of buildings

    Microsoft Academic Search

    B. C. Cha; R. O. Mueller

    1979-01-01

    A novel two-tank storage system is discussed consisting of a large seasonal storage tank for summer collection, and a diurnal storage tank for collection of solar energy during the winter heating season. An approach to simulation of the system has been developed and is described. It includes modelling of a flat-plate collector, the two fully-mixed storage tanks, two load heat-exchangers,

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

    Microsoft Academic Search

    Guiyin Fang; Xu Liu

    2010-01-01

    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

  9. Fluid Latent Heat Storage Materials Using Natural Substances

    NASA Astrophysics Data System (ADS)

    Hokamura, Haku; Ohkubo, Hidetoshi

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

  10. The role of heat storage in the soil in the energy balance of a greenhouse 

    E-print Network

    Sadler, Edward John

    1978-01-01

    Instrumentation. Procedures Used to Validate the Hodel. Procedures Used to Evaluate the Significance of the Storage of Heat in the Soil IV. RESULTS AND DISCUSSION. Validation of the Nodel. Significance of the Storage of Heat in the Soil. V. SUPVIARY... the canopy level. This simplification allowed more rapid model development and less extensive computations. However, the authors agreed that the sig- nificance of the soil heat storage snould be invest. igated in a later study. This is the problem...

  11. Heat transfer enhancement of high temperature thermal energy storage using metal foams and expanded graphite

    Microsoft Academic Search

    C. Y. Zhao; Z. G. Wu

    2011-01-01

    Latent heat storage (LHS) can theoretically provide large heat storage density and significantly reduce the storage material volume by using the material’s fusion heat, ?hm. Phase change materials (PCMs) commonly suffer from low thermal conductivities, being around 0.4Wm?1K?1 for inorganic salts, which prolong the charging and discharging period. The problem of low thermal conductivity is a major issue that needs

  12. Exergetic Evaluation of an Organic Rankine Cycle Using Medium-Grade Waste Heat

    Microsoft Academic Search

    P. J. Mago

    2012-01-01

    This article presents an exergetic analysis for an organic Rankine cycle that converts waste energy to power from medium-grade heat sources (503 to 923 K). In addition, the effect of the waste heat temperature, the evaporator pressure, and the pinch point temperature difference on the thermal and exergetic performance of the system is studied. Several organic working fluids were selected

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

    Microsoft Academic Search

    J. M. Zhao; L. H. Liu

    2007-01-01

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

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

    Microsoft Academic Search

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

    2004-01-01

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

  15. Solid media thermal storage for parabolic trough power plants

    Microsoft Academic Search

    Doerte Laing; Wolf-Dieter Steinmann; Rainer Tamme; Christoph Richter

    2006-01-01

    For parabolic trough power plants using synthetic oil as the heat transfer medium, the application of solid media sensible heat storage is an attractive option regarding investment and maintenance costs. In the project WESPE that is described in this paper, solid media sensible heat storage materials have been researched. Two storage systems with a storage capacity of about 350kWh each

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

    Microsoft Academic Search

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

    2007-01-01

    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

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

    Microsoft Academic Search

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

    1997-01-01

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

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

    E-print Network

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

    1980-01-01

    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...

  19. An appraisal of one-dimensional analytical models for the packed bed thermal storage systems utilizing sensible heat storage materials

    Microsoft Academic Search

    G. A. Adebiyi; D. J. Chenevert

    1996-01-01

    This article gives an appraisal of existing analytical one-dimensional models for the packed bed thermal energy storage (TES) systems utilizing sensible heat storage (SHS) materials. The models include that of Schumann, which is for separate phases, but does not include axial conductivity (or dispersion) in the bed, nd the single-phase model of Riaz which includes axial dispersion. An alternative axial

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

    Microsoft Academic Search

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

    1995-01-01

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

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

    Microsoft Academic Search

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

    2009-01-01

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

  2. Heating of the interstellar medium by the solar wind

    NASA Technical Reports Server (NTRS)

    Kunc, J. A.; Wu, F. M.; Judge, D. L.

    1983-01-01

    The heating of inflowing interstellar gas by the solar wind is calculated. The experimental differential cross sections have been used for calculating electron-H(He) and proton-H(He) elastic scattering rate coefficients. The solar wind is assumed to be a two-component (protons and electrons), steady, spherically symmetric stream moving radially outward, with the inflowing gas following Keplerian trajectories. The spatial distributions of effective temperature increase within interplanetary space have been obtained.

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

    Microsoft Academic Search

    Francis Agyenim; Neil Hewitt; Philip Eames; Mervyn Smyth

    2010-01-01

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

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

    Microsoft Academic Search

    Yuichi Hamada; Wataru Ohtsu; Jun Fukai

    2003-01-01

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

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

    Microsoft Academic Search

    Viorel Badescu

    2003-01-01

    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

  6. Metal-halide mixtures for latent heat energy storage

    NASA Technical Reports Server (NTRS)

    Chen, K.; Manvi, R.

    1981-01-01

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

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

    E-print Network

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

    2006-01-01

    ICEBO2006, Shenzhen, China Re newable Energy Resources and a Greener Future Vol.VIII-2-4 Numerical Simulation of a Latent Heat Storage System of a Solar-Aided Ground Source Heat Pump Fang Wang Maoyu Zheng Zhongjian Li... begins from 12th, Mar.,2004 to 10th,Apr.2004, the system had run for 30days. 1ST Apr. and 4th Apr. were cloudy and rainy days, storage time was short or there was no storage in the PCST in these two days. Ground source heat pump was as the sole...

  8. Energy storage-boiler tank using salt fusion and heat piping

    Microsoft Academic Search

    1977-01-01

    An energy storage system useful for storing energy due to sun light and making use of the stored energy when the sun is not shining is described. The storage tank system includes a liquid therein which is heated as a result of the sun's energy. The heated liquid evaporates and subsequently condenses onto cans of a salt. The condensing liquid

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

    Microsoft Academic Search

    Guiyin Fang; Xu Liu; Shuangmao Wu

    2009-01-01

    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)

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

    E-print Network

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

    2006-01-01

    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...

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

    Microsoft Academic Search

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

    1978-01-01

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

  12. Modifying a Mesoscale Meteorological Model to Better Incorporate Urban Heat Storage: A Bulk-Parameterization Approach

    Microsoft Academic Search

    Haider Taha

    1999-01-01

    A simple bulk-parameterization scheme is implemented in modifying a mesoscale meteorological model to better incorporate urban heat storage. The objective is to improve the quantification of the fluxes associated with heat storage change and to more explicitly account for the integrated effect of urban canopy layer fluxes on the overlying boundary layer. The approach involves integrating an Objective Hysteresis Model

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

    Microsoft Academic Search

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

    2004-01-01

    The heat storage anomaly of the upper ocean can be estimated using altimeter data, based on the thermal dynamics equation. In this study, we analyzed both nonthermal and thermal steric height measured by altimetry, and removed nonthermal steric height from altimeter measurements to calculate the heat storage anomaly from thermal steric height alone in the global oceans, but with a

  14. Numerical and experimental study on heat pump water heater with PCM for thermal storage

    Microsoft Academic Search

    Jian-You Long; Dong-Sheng Zhu

    2008-01-01

    An air source heat pump water heater with phase change material (PCM) for thermal storage was designed to take advantage of off-peak electrical energy. The heat transfer model of PCM was based upon a pure conduction formulation. Quasi-steady state method was used to calculate the temperature distribution and phase front location of PCM during thermal storage process. Temperature and thermal

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

    NASA Astrophysics Data System (ADS)

    Solomon, A. D.

    1985-12-01

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

  16. Evaluation of ground-source heat pump combined latent heat storage system performance in greenhouse heating

    Microsoft Academic Search

    Hüseyin Benli; Ayd?n Durmu?

    2009-01-01

    The use of renewable energy for greenhouse heating in winter and cold days, helps to save fossil fuels and conserve green farm environment on the one hand, and on the other hand, enhances the quality of agricultural products, reduces production costs and limits the release of greenhouse gases. In this study, a ground-source heat pump-phase change material (GSHP-PCM) latent heat

  17. Combustion of medium heating value coal gas at turbine operating conditions

    Microsoft Academic Search

    J. A. Schwab; D. C. Cicero; R. S. Basel

    1982-01-01

    The work described in this paper is part of the effort performed under Department of Energy (DOE) Contract DE-AC21-80ETI4752. The primary objective of this contract is to demonstrate the viability of the Westinghouse pressurized, fluidized bed gasification process for production of low and medium heating value fuel gas. One of many secondary objectives is to conduct combustion tests with medium

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

    PubMed Central

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

    1988-01-01

    An analysis is presented of diffusional delays in one-dimensional heat flow through a medium consisting of several layers of different materials. The model specifically addresses the measurement of heat production by muscle, but diffusion of solute or conduction of charge through a layered medium will obey the same equations. The model consists of a semi-infinite medium, the muscle, in which heat production is spacially uniform but time varying. The heat diffuses through layers of solution and insulation to the center of the thermal element where heat flow is zero. Using Laplace transforms, transfer functions are derived for the temperature change in the center of the thermopile as a function of the temperature at any interface between differing materials or as a function of heat production in the muscle. From these transfer functions, approximate analytical expressions are derived for the time constants which scale the early and late changes in the central temperature. We find that the earliest temperature changes are limited by the diffusivities of the materials, whereas the approach to steady state depends on the total heat capacity of the system and the diffusivity of muscle. Hill (1937) analyzed a similar geometry by modeling the layered medium as a homogeneous system with an equivalent half thickness. We show that his analysis was accurate for the materials in his system. In general, however, and specifically with regard to modern thermopiles, a homogeneous approximation will lead to significant errors. We compare responses of different thermopiles to establish the limits of time resolution in muscle heat records and to correct them for diffusional delays. Using numerical techniques, we invert the Laplace transforms and show the time course of the temperature changes recorded by different instruments in response to different patterns of heat production. PMID:3224146

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

    SciTech Connect

    Pelka, W.

    1980-07-01

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

  20. Laser heating of uncoated optics in a convective medium.

    PubMed

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

    2012-05-10

    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

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

    NASA Technical Reports Server (NTRS)

    Mahefkey, E. T.; Richter, R.

    1981-01-01

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

  2. Effect of pre-storage heat treatment on enzymological changes in peach.

    PubMed

    Bakshi, Parshant; Masoodi, F A

    2010-08-01

    Peach (Prunus persica (L.) Batsch) fruit was subjected to hot water and moist hot air treatment at varying temperatures. The activities of polyphenoloxidase (PPO) and polygalacturonase (PG) were monitored during storage for 0, 3 and 6 days. PPO activity decreased in all treatments during storage. This decrease was more in hot water treated fruits than in hot air. PPO activity decreased with the increase in treatment duration. However, the PG activity increased in heat treated fruits as well as control. This increase was more in mild heat treatments as compared to severe heat treatment. Both polyphenol and pectin contents decreased during storage in both heat treatments. PMID:23572672

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

    NASA Technical Reports Server (NTRS)

    Lurio, Charles A.

    1992-01-01

    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.

  4. Survival of Lactobacillus sakei during heating, drying and storage in the dried state when growth has occurred in the presence of sucrose or monosodium glutamate.

    PubMed

    Ferreira, Vânia; Soares, Vânia; Santos, Cristina; Silva, Joana; Gibbs, Paul A; Teixeira, Paula

    2005-02-01

    Spray-dried cells of Lactobacillus sakei CTC 494 survived ca. 60% longer in the spray dried state when cells were grown in the presence of 20 g sucrose l(-1) or 12.5 g monosodium glutamate l(-1). No significant differences were observed in viability during storage in the freeze dried state with the addition of these compounds to the growth medium, nor in survival during a heat treatment (55 degrees C). Both sucrose and glutamate in the growth medium suppressed intracellular accumulation of total amino acids and changed the overall pattern of the individual amino acids. Glutamate in the growth medium enhanced intracellular glutamate by ca. 38%. PMID:15742145

  5. Waste heat recovery from heavy-duty diesel engine exhaust gases by medium temperature ORC system

    Microsoft Academic Search

    MingShan Wei; JinLi Fang; ChaoChen Ma; Syed Noman Danish

    A medium-temperature waste-heat recovery system based on the organic Rankine cycle (ORC) is designed to recover the exhaust\\u000a energy from a heavy-duty diesel engine. Analysis of the 1st law of thermodynamics for an ORC system is performed. This analysis\\u000a contains two parts. The first part is an analysis with undefined heat exchangers to gain an understanding of the ORC and

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

    Microsoft Academic Search

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

    2008-01-01

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

  7. Li-doped B2C graphene as potential hydrogen storage medium

    NASA Astrophysics Data System (ADS)

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

    2011-04-01

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

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

    PubMed

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

    2012-07-01

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

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

    Microsoft Academic Search

    MARINA DOJ

    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

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

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

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

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

    E-print Network

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

    2006-01-01

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

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

    Microsoft Academic Search

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

    2006-01-01

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

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

    Microsoft Academic Search

    R. Yumruta?; M. Ünsal

    2000-01-01

    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

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

    E-print Network

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

    2006-01-01

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

  15. Modeling of fixed bed heat storage units utilizing phase change materials

    Microsoft Academic Search

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

    1987-01-01

    A computer model has been developed for the calculation of the heat exchanged and temperature profiles in a packed bed containing a phase change material. The packed bed is intended as a heat storage unit in which an inert fluid flowing through the bed exchanges heat with an encapsulated spherical shot of the phase change (melting and freezing) material. Examples

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

    NASA Astrophysics Data System (ADS)

    Telgozhayeva, D. S.

    2014-08-01

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

  17. Storage of thermal energy for effective use of waste heat from industries

    Microsoft Academic Search

    J. Yagi; T. Akiyama

    1995-01-01

    Energy saving is one of the most effective strategies to protect the global environmental conditions. At present, considerable amount of waste heat is emitted from metallurgical and chemical industries, which can be used not only for municipal purposes but also for industries if recovered.In this paper, fundamental studies on heat transfer was conducted for developing a heat storage process by

  18. Thermal energy storage systems using fluidized bed heat exchangers

    NASA Technical Reports Server (NTRS)

    Weast, T.; Shannon, L.

    1980-01-01

    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.

  19. Methanol-based heat pump for solar heating, cooling, and storage. Phase III. Final report

    SciTech Connect

    Offenhartz, P O'D; Rye, T V; Malsberger, R E; Schwartz, D

    1981-03-01

    The reaction of CH/sub 3/OH vapor with solid (pellet) CaCl/sub 2/ to form the solid phase compound CaCll/sub 2/ . 2CH/sub 3/OH can be used as the basis of a combined solar heat pump/thermal energy storage system. Such a system is capable of storing heat indefinitely at ambient temperature, and can be used for space and domestic hot water heating, and for air conditioning with forced air (dry) heat rejection. It combines all features required of a residential or commercial space conditioning system except for solar collection. A detailed thermal analysis shows that the coefficient of performance for heating is greater than 1.5, and for cooling, greater than 0.5. This has been confirmed by direct experimental measurement on an engineering development test unit (EDTU). The experimental rate of CH/sub 3/OH absorption is a strong function of the absorber-evaporator temperature difference. The minimum practical hourly rate, 0.10 moles CH/sub 3/OH per mole CaCl/sub 2/, was observed with the salt-bed heat transfer fluid at 40/sup 0/C and the CH/sub 3/OH evaporator at -15/sup 0/C. a detailed performance and economic analysis was carried out for a system operated in Washington, DC. With 25 square meters of evacuated tube solar collectors, the CaCl/sub 2/-CH/sub 3/OH chemical heat pump should be capable of meeting over 90% of the cooling load, 80% of the heating load, and 70% of the domestic hot water load with nonpurchased energy in a typical well-insulated single family residence, thus saving about $600 per year. In small-scale production, the installed cost of the system, including solar collectors and backup, is estimated to be about $10,000 greater than a conventional heating and cooling system, and a much lower cost should be possible in the longer term.

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

    PubMed

    Uddin, Ziya; Harmand, Souad

    2013-01-01

    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

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

    PubMed Central

    2013-01-01

    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

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

    Microsoft Academic Search

    R. R. Hautala; C. R. Kutal

    1976-01-01

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

  3. Relations for local radiative heat transfer between rectangular boundaries of an absorbing-emitting medium

    NASA Technical Reports Server (NTRS)

    Siegel, R.

    1993-01-01

    An analytical solution was obtained by Siegel (1991, 1992) for local boundary heat fluxes by a radiating medium at uniform temperature in a 2D rectangular region. It is shown here that, after local fluxes from the medium to the walls have been evaluated, it is very easy to compute local fluxes arriving from the adjacent and opposite walls. This extends the previous analysis and provides convenient relations to include radiation from a black boundary, each side of the rectangle being at a different uniform temperature. The final expressions are helpful in performing spectral calculations that must be made for many spectral bands.

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

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

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

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

    E-print Network

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

    1982-01-01

    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...

  6. Heat storage material comprising calcium chloride-hexahydrate and a nucleating agent

    SciTech Connect

    Gawron, K.; Schroder, J.

    1980-02-19

    The utility of calcium chloride-hexahydrate as a heat storage material is improved when barium carbonate, strontium carbonate, barium fluoride, barium fluoride-hydrofluoride and/or strontium fluoride is used as a nucleating agent to prevent supercooling.

  7. A direct-heating energy-storage receiver for dish-Stirling solar energy systems

    Microsoft Academic Search

    K. O. Lund

    1996-01-01

    Dish-Stirling solar receiver designs are investigated and evaluated for possible use with sensible energy storage in single-phase materials. The designs differ from previous receivers in utilizing axial conduction in the storage material for attenuation of the solar flux transients due to intermittent cloud cover, and in having convective heat removal at the base of the receiver. One-dimensional, time-dependent heat transfer

  8. Heating the intra-cluster medium by jet-inflated bubbles

    E-print Network

    Hillel, Shlomi

    2015-01-01

    We examine the heating of the intra-cluster medium (ICM) of cooling flow clusters of galaxies by jet-inflated bubbles and conclude that mixing of hot bubble gas with the ICM is the dominate heating process. We use the PLUTO hydrodynamical code in full 3D to properly account for the inflation of the bubbles and to the multiple vortices induced by the jets and bubbles. The vortices mix some hot shocked jet gas with the ICM. For the parameters used the mixing process accounts for approximately 80% of the energy transferred from the jets to the ICM. Only about 20% of the transferred energy is channelled to the kinetic energy of the ICM. Part of this develops as ICM turbulence. We conclude that turbulent heating plays a smaller role than mixing. Heating by shocks is less efficient even.

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

    SciTech Connect

    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

    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.

  10. Numerical model and experimental validation of heat storage with phase change materials

    Microsoft Academic Search

    Jacques Bony; Stéphane Citherlet

    2007-01-01

    This paper describes the numeric model developed to simulate heat transfer in phase change materials (PCM) plunged in water tank storage. This model, based on the enthalpy approach, takes into account the conduction and the convection into PCM as well as at the interface between PCM and water of the storage. Furthermore, hysterisis and subcooling are also included. This model

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

    E-print Network

    Vincent, Warwick F.

    Simulated heat storage in a perennially ice-covered high Arctic lake: Sensitivity to climate change transfer in one of these lakes (Lake A, latitude 83.0°N, longitude 75.4°W) was simulated using a high storage in a perennially ice-covered high Arctic lake: Sensitivity to climate change, J. Geophys. Res

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

    Microsoft Academic Search

    JEAN PARIS; MICHEL FALARDEAU; CÉCILE VILLENEUVE

    1993-01-01

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

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

    Microsoft Academic Search

    S. Fischer

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

  14. Heating the intra-cluster medium perpendicular to the jets axis

    NASA Astrophysics Data System (ADS)

    Gilkis, Avishai; Soker, Noam

    2012-12-01

    By simulating jet-inflated bubbles in cooling flows with the PLUTO hydrodynamic code we show that mixing of high entropy shocked jet's material with the intra-cluster medium (ICM) is the major heating process perpendicular to the jets' axis. Heating by the forward shock is not significant. The mixing is very efficient in heating the ICM in all directions, to distances of ˜10 kpc and more. Although the jets are active for a time period of only 20 Myr, the mixing and heating near the equatorial plane, as well as along the symmetry axis, continues to counter radiative cooling for times of >rsim 108 yr after the jets have ceased to exist. We discuss some possible implications of the results. (i) The vigorous mixing is expected to entangle magnetic field lines, hence to suppress any global heat conduction in the ICM near the centre. (ii) The vigorous mixing forms multi-phase ICM in the inner cluster regions, where the coolest parcels of gas will eventually cool first, flow inwards and feed the active galactic nucleus to set the next jet-activity episode. This further supports the cold feedback mechanism. (iii) In cases where the medium outside the region of r ˜ 10 kpc is not as dense as in groups and clusters of galaxies, like during the process of galaxy formation, the forward shock and the high pressure of the shocked jets' material might expel gas from the system.

  15. Three dimensional Couette flow and heat transfer through a porous medium with variable permeability.

    PubMed

    Chaudhary, R C; Sharma, Pawan Kumar

    2003-01-01

    This paper reports research on the effects of variations in injection velocity and permeability on the heat transfer and flow through a highly porous medium between two horizontal parallel plates situated at constant distance with constant suction by the upper plate. Due to this type of variation in injection velocity and in permeability the flow becomes three dimensional. The governing equations are solved by adopting complex variable notations to obtain the expressions for the velocity and temperature field. The skin-friction along the main flow direction and rate of heat transfer are discussed with the help of graphs. PMID:12659232

  16. Energy storage for nuclear burst power systems

    Microsoft Academic Search

    D. G. Morris; M. Olszewski

    1987-01-01

    Energy can be stored in a thermal energy storage (TES) medium and integrated into the heat rejection system to reduce the radiator size. This occurs by placing all or a significant fraction of the sprint reject heat into storage during burst operation. The stored heat is then rejected during the longer non-operational period of the orbit. Down-sizing of the radiator

  17. Cascaded latent heat storage for parabolic trough solar power plants

    Microsoft Academic Search

    Horst Michels; Robert Pitz-Paal

    2007-01-01

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

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

    Microsoft Academic Search

    Ioan Sauciuc; Aliakbar Akbarzadeh; Peter Johnson

    1995-01-01

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

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

    E-print Network

    Zhu, N.

    2014-01-01

    heat pump system integrated with phase change cooling storage technology could save energy and shift peak load. This paper studied the optimal design of a ground source heat pump system integrated with phase change thermal storage tank in an office... heat pump system integrated with solar ESL-IC-14-09-18 Proceedings of the 14th International Conference for Enhanced Building Operations, Beijing, China, September 14-17, 2014 heating storage technology, and it is concluded that the system save energy...

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

    SciTech Connect

    Strickland, G

    1980-08-01

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

  1. Mathematical model of self-sustaining combustion in inert porous medium with phase change under complex heat transfer

    Microsoft Academic Search

    R. Echigo; H. Yoshida

    1998-01-01

    The phenomenon of self-sustaining combustion of a gaseous mixture in inert high porous medium with prior vaporization of liquid droplets is studied by means of a numerical simulation. The complex heat transfer includes convective, conductive and radiative heat transfer between three phases: gas, solid and liquid. Evaporation and different modes of convective heat transfer between liquid, gaseous and solid phases

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

    Microsoft Academic Search

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

    1996-01-01

    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

  3. Thermal analysis of a helical heat exchanger for ground thermal energy storage in arid zones

    Microsoft Academic Search

    Y. Rabin; E. Korin

    1996-01-01

    A mathematical model for thermal analysis of a helical heat exchanger for long-term thermal energy storage in soil for use in arid zones was developed. The helical heat exchanger was modeled as a series of horizontal rings with a constant pitch distance between them. The model was solved by a finite difference method, using a microcomputer, and validated with experimental

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

    Microsoft Academic Search

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

    1997-01-01

    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

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

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

    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.

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

    Microsoft Academic Search

    Somchai Jiajitsawat; John Duffy

    2008-01-01

    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

  7. Effect of solar storage wall on the passive solar heating constructions

    Microsoft Academic Search

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

    2011-01-01

    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

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

    E-print Network

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

    2006-01-01

    performance. REFERENCE [1] Jan-Olof Dalenback, Central solar heating plant with seasonal storage---Status Report[M], IEA Technical Report, 1990. [2] Werner Weiss. Solar heating systems for houses[M]. Jame & James Ltd. 2003. [3] ASHRAE. Solar energy...

  9. Field test and assessment of thermal energy storage for residential heating

    SciTech Connect

    Hersh, H.

    1983-12-01

    Thermal energy storage (TES) heating units can be connected to the utility grid to accept electricity only during utility off-peak periods and yet provide round-the-clock comfort heating. Their use by an increasingly larger part of the electric-heat market could provide economic and oil-saving benefits. A field test was carried out over two full heating seasons in Vermont and Maine at 45 TES sites and 30 control sites heated by electric baseboard heaters. The TES users were billed under applicable time-of-day (TOD) rates. All sites were instrumented, and measurements of inside and outside temperatures and electrical energy consumption for heating were made and recorded every 15 min. Analysis of the data has led to the following findings and conclusions: Overall technical performance of the TES units was good under extreme weather conditions. Annualized energy use was the same for the TES and the control households. Proper sizing of the storage systems is much more important for storage heaters than for nonstorage heaters. TES users were satisfied with performance. Electric-heat bills were much lower for TES users. Occupancy effects were large and caused wide variations in energy consumption on days that had the same number of heating degree-days. The individual building heat loss determined experimentally from an analysis of the actual energy consumption per heating degreeday was 30% to 50% smaller than that determined by a walkthrough energy audit.

  10. Mathematical Modeling of Magneto Pulsatile Blood Flow Through a Porous Medium with a Heat Source

    NASA Astrophysics Data System (ADS)

    Sharma, B. K.; Sharma, M.; Gaur, R. K.; Mishra, A.

    2015-05-01

    In the present study a mathematical model for the hydro-magnetic non-Newtonian blood flow in the non-Darcy porous medium with a heat source and Joule effect is proposed. A uniform magnetic field acts perpendicular to the porous surface. The governing non-linear partial differential equations have been solved numerically by applying the explicit finite difference Method (FDM). The effects of various parameters such as the Reynolds number, hydro-magnetic parameter, Forchheimer parameter, Darcian parameter, Prandtl number, Eckert number, heat source parameter, Schmidt number on the velocity, temperature and concentration have been examined with the help of graphs. The present study finds its applications in surgical operations, industrial material processing and various heat transfer operations.

  11. Effect of oxidizing medium and heat treatment on stoichiometry of ZnSe crystal surface

    NASA Astrophysics Data System (ADS)

    Sotnikov, V. T.; Dobrotvorskiy, S. S.

    1984-10-01

    The chemical composition of ZnSe crystals at the surface after heat treatment under vacuum, without and with an oxidizing medium, was studied by both Auger electron spectroscopy and secondary ion mass spectroscopy. Heating without oxidation resulted in a higher surface concentration of Se atoms, these excess Se atoms being accompanied by Na, K. Li, Cs impurity atoms. Surface oxidation was effected plainly with commercial oxygen at room temperature, with traces of water vapor as well as with stimulation and intensification by electron bombardment. The spectra of Auger electrons and the kinetics of these spectra under the various conditions of heat treatment reveal intense oxidation and hydrolysis of the Zn Se surface, accompanied by a decrease of the Se surface concentration and an increase of the Zn surface concentration along with formation of ZnOH and Zn(OH)2 hydroxides indicated by the ion mass spectra. The spectra also indicate a thermomechanical mechanism of oxidation during electron bombardment.

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

    NASA Astrophysics Data System (ADS)

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

    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.

  13. Modeling of fixed bed heat storage units utilizing phase change materials

    Microsoft Academic Search

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

    1987-01-01

    A computer model has been developed for the calculation of the heat exchanged and temperature profiles in a packed bed containing\\u000a a phase change material. The packed bed is intended as a heat storage unit in which an inert fluid flowing through the bed\\u000a exchanges heat with an encapsulated spherical shot of the phase change (melting and freezing) material. Examples

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

    SciTech Connect

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

    1986-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    1988-06-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    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.

  17. Heat extraction for the CSPonD thermal storage unit

    E-print Network

    Rojas, Folkers Eduardo

    2011-01-01

    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 ...

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

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

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

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

    SciTech Connect

    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

    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.

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

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Yi, Hong-Liang; Tan, He-Ping

    2013-05-01

    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.

  1. Theoretical analysis of screened heat pipes for medium and high temperature solar applications

    NASA Astrophysics Data System (ADS)

    Di Marco, P.; Filippeschi, S.; Franco, A.; Jafari, D.

    2014-11-01

    A mathematical model is applied to study the cylindrical heat pipes (HPs) behaviour when it is exposed to higher heat input at the evaporator for solar collector applications. The steady state analytical model includes two-dimensional heat conduction in the wall, the liquid flow in the wick and vapour hydrodynamics, and can be used to evaluate the working limits and to optimize the HP. The results of the analytical model are compared with numerical and experimental results available in literature, with good agreement. The effects of heat transfer coefficient, power input, evaporator length, pipe diameter, wick thickness and effective pore radius on the vapour temperature, maximum pressure drop and maximum heat transfer capability (HTC) of the HP are studied. The analysis shows that wick thickness plays an important role in the enhancement of HTC. Results show that it is possible to improve HTC of a HP by selecting the appropriate wick thickness, effective pore radius, and evaporator length. The parametric investigations are aimed to determine working limits and thermal performance of HP for medium temperature solar collector application.

  2. Advanced latent heat storage media for high-temperature industrial applications

    Microsoft Academic Search

    M. Olszewski

    1984-01-01

    Several advanced thermal energy storage (TES) media are being developed for high temperature industrial applications. One of the concepts involves a composite medium consisting of a phase-change carbonate salt supported and immobilized within a submicro sized capillary structure of a particulate ceramic matrix or porous sintered ceramic. Immobilization of the molten salt within the ceramic structure permits operation of the

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

    Microsoft Academic Search

    R. R. Hautala; C. R. Kutal

    1977-01-01

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

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

    E-print Network

    Zhu, N.

    2014-01-01

    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...

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

    PubMed Central

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

    2013-01-01

    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

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

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

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

  7. Heat removal characteristics of waste storage tanks. Revision 1

    SciTech Connect

    Kummerer, M.

    1995-10-01

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

  8. Heat transfer and thermal storage behaviour of gypsum boards incorporating micro-encapsulated PCM

    Microsoft Academic Search

    Chi-ming Lai; R. H. Chen; Ching-Yao Lin

    2010-01-01

    In the application of energy storage and thermal environmental control, PCM (Phase Change Material) is a very promising material choice. This study incorporated mPCM (micro-encapsulated PCM) into gypsum to make mPCM gypsum board and then investigated the physical properties, heat transfer and thermal storage behaviour. The major control parameters are wall temperatures and the weight percentages of mPCM added to

  9. High temperature composite thermal storage systems

    Microsoft Academic Search

    R. J. Petri; M. Olszewski; E. T. Ong

    1984-01-01

    An advanced, thermal energy storage subsystem is being developed by IGT which employs composite phase change material (PCM)\\/sensible heat material media. This medium\\/subsystem is amenable to high temperature thermal storage applications such as industrial reject\\/process heat recovery and utilization, off-peak utility and solar thermal power system applications. The concept allows for direct contact heat exchange between the latent\\/ sensible storage

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

    Microsoft Academic Search

    Ibrahim A. Abdallah

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

  11. Photoionization and heating of a supernova-driven turbulent interstellar medium

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Misra, Ajay K.

    1988-01-01

    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.

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

    PubMed

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

    2010-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

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

    PubMed

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

    2012-06-01

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

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

    PubMed

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

    2015-01-14

    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

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

    NASA Astrophysics Data System (ADS)

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

    2005-12-01

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

  18. Plastic solar panel, heat storage, baseboard heating system for both swimming pool and home

    Microsoft Academic Search

    1977-01-01

    A solar energy heating system has been developed which used a $27.50\\/m² plastic panel to supply hot water, space heating, and swimming pool heat for a 150 m² home in Northern California. Panels are 24 m², inclined 50°, covered with a thin Tedlar sheet, produce 55°C water at 90 kg\\/hr. The 55°C solar-heated water is first heat exchanged through the

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

    NASA Technical Reports Server (NTRS)

    Bootle, John

    2008-01-01

    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.

  20. Two-tank working gas storage system for heat engine

    DOEpatents

    Hindes, Clyde J. (Troy, NY)

    1987-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    1987-07-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    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.

  3. Analysis of Heat Charging and Discharging on the Phase Change Energy-Storage Composite Wallboard (PCECW) in Building 

    E-print Network

    Yue, H.; Chen, C.; Liu, Y.; Guo, H.

    2006-01-01

    -storage characteristics of the PCECW according to phase change energy-storage theory, which is used as the storage-heat body in the “light" inner wallboards, compared to the normal “heavy" inner wallboards. Through computer simulation, we measured the effects...

  4. Experimental and simulated temperature distribution of an oil-pebble bed thermal energy storage system with a variable heat source

    Microsoft Academic Search

    A. Mawire; M. McPherson

    2009-01-01

    Axial temperature distributions of a thermal energy storage (TES) system under variable electrical heating have been investigated. An electrical hot plate in thermal contact with a hollow copper spiral coil through which the oil flows simulates a solar collector\\/concentrator system. The hot plate heats up the oil which flows through the storage thus charging the TES system at a constant

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

    Microsoft Academic Search

    Kang Yanbing; Zhang Yinping; Jiang Yi; Zhu Yingxin

    1999-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Soda, Michael John

    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.

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

    Microsoft Academic Search

    Ulf Herrmann; Bruce Kelly; Henry Price

    2004-01-01

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

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

    E-print Network

    Barineau, Mark Michael

    2010-01-01

    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 ...

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

    E-print Network

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

    1979-01-01

    been performed on these systems and will be presented. Through use of thermal energy storage in conjunction with waste heat electric power generation units, an estimated 2.4 x 1013 BTU per year, or an equivalent of 4.0 x 10 barrels of oil per year, can...

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

    E-print Network

    Tackett, R. K.

    1989-01-01

    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...

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

    Microsoft Academic Search

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

    1992-01-01

    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

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

    Microsoft Academic Search

    Brian Vad Mathiesen; Henrik Lund

    2005-01-01

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

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

    Microsoft Academic Search

    Amar Khudhair; Mohammed Farid; Necati Ozkan; John Chen

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

  14. Development of enhanced heat transfer/transport/storage slurries for thermal-system improvement

    SciTech Connect

    Kasza, K.E.; Chen, M.M.

    1983-01-01

    This paper presents a formulation of a new concept for improving thermal-system performance by utilizing the combined mechanisms of enhanced heat transfer, transport, and thermal-energy storage associated with a phase-change slurry as the working fluid.

  15. Use of infrared thermography for the evaluation of heat losses during coal storage

    Microsoft Academic Search

    V Fierro; J. L Miranda; C Romero; J. M Andrés; A Pierrot; E Gómez-Landesa; A Arriaga; D Schmal

    1999-01-01

    The exothermic processes during coal storage reduce the calorific value of the coal which in turn results in financial losses. An accurate and easy calculation of the losses may be an efficient tool to evaluate the effectiveness of the measures taken to reduce the spontaneous heating of coal and to predict the appearance of hot spots. This study was carried

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

    NASA Astrophysics Data System (ADS)

    Sawada, Hisashi; Okada, Masashi; Nakagawa, Shinji

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

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

    NASA Astrophysics Data System (ADS)

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

    1988-05-01

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

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

    SciTech Connect

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

    1991-06-01

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

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

    PubMed

    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

    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

  20. Sulfur Based Thermochemical Heat Storage for Baseload Concentrated Solar Power Generation

    SciTech Connect

    wong, bunsen

    2014-11-20

    This project investigates the engineering and economic feasibility of supplying baseload power using a concentrating solar power (CSP) plant integrated with sulfur based thermochemical heat storage. The technology stores high temperature solar heat in the chemical bonds of elemental sulfur. Energy is recovered as high temperature heat upon sulfur combustion. Extensive developmental and design work associated with sulfur dioxide (SO2) disproportionation and sulfuric acid (H2SO4) decomposition chemical reactions used in this technology had been carried out in the two completed phases of this project. The feasibility and economics of the proposed concept was demonstrated and determined.

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

  2. Using Sea Level to Probe Linkages Between Heat Transport Convergence, Heat Storage Rate, and Air-Sea Heat Exchange in the Subtropical North Atlantic

    NASA Astrophysics Data System (ADS)

    Thompson, L.; Kelly, K. A.; Booth, J. F.

    2014-12-01

    Annual mean surface heat fluxes from the ocean to the atmosphere in midlatitudes are maximum in the Gulf Stream and that surface flux is driven by geostrophic heat transport convergence. Evidence is mounting that on interannual times scales, the surface flux of heat in the Gulf Stream region is controlled by the amount of heat that is stored in the region and that the heat storage rate is in turn controlled by geostrophic heat transport convergence. In addition, variations in meridional heat transport have been linked to the meridional overturning circulation just to the south of the Gulf Stream at the RAPID/MOCHA array at 26.5N, suggesting that changes in the meridional overturning circulation might be linked to surface heat exchange in the Gulf Stream. The twenty-year record of satellite sea level (SSH) along with high quality surface heat fluxes allow a detailed evaluation of the interaction between stored oceanic heat in this region and surface heat fluxes on interannual times scales. Using gridded sea level from AVISO as a proxy for upper ocean heat content along with surface turbulent heat flux from OAFlux, we evaluate the lagged correlations between interannual surface turbulent heat fluxes and SSH variability. Previous work has shown that where advection is small lagged correlations between SST (sea surface temperature) and surface turbulent heat flux are generally antisymmetric about zero lag with negative correlations when SST leads and positive correlations when SST lags. This indicates that surface heat fluxes force SST anomalies that at later times are damped by surface fluxes. In contrast, the lagged correlation between SSH anomalies and the turbulent flux of heat in the Gulf Stream region show a distinctly asymmetric relationship about zero-lag. The correlations are negative when SSH leads but are not significant when SSH lags indicating the dominant role in heat transport convergence in driving heat content changes, and that the heat content anomalies generated control the exchange of heat between the ocean and the atmosphere. Seasonal analysis shows that the Gulf Stream region's heat content primarily is primarily released in winter and that in winter, SSH also gives significant predictive skill for mid-level cloud fraction.

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

    PubMed

    Wei, Jiancang; Suin, Jianjun; Wu, Jian

    2013-02-01

    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

  4. Survival of Microorganisms in a Rock Bed Under Conditions Simulating Solar Heat Storage

    PubMed Central

    Zervins, Andris; Babcock, Michael; Stone, Robert W.

    1981-01-01

    A laboratory-scale unit containing about 360 kg of washed river gravel was designed to [ill] the use of rocks for heat storage. The unit was operated under varying conditions of temperature, relative humidity, and the addition of volatile nutrients over a 4-month period. Effluent air and rock surfaces were monitored for the presence of microorganisms. After 2 weeks, virtually no microorganisms were detected in the effluent air except when dry soil or compost was added as the inoculum. A small number of heat-resistant bacteria, but no fungi, were found to survive on the rock surfaces. Microorganisms isolated were either sporeforming bacteria or actinomycetes closely resembling Thermoactinomyces vulgaris. Microbial colonization of rock beds used for solar heat storage does not appear likely under routine operation. PMID:16345765

  5. Evaluation of industrial advanced heat-recovery/thermal-energy-storage systems, volume 2

    NASA Astrophysics Data System (ADS)

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

    1982-12-01

    The recovery of waste heat from industrial processes offers significant opportunity for energy conservation provided the available energy source can be matched with a compatible energy consuming sink or end-use process. This investigation involved: examining plant and process energy data acquired during on-site visits to 12 industrial plants from which 24 candidate applications were identified where thermal energy storage would be necessary either to make possible or to enhance the recovery and reuse of industrial waste energy; compiling cost and performance data for commercially available equipment to recover, store and transfer waste heat between source and sink processes on demand; and assessing the economic benefits, possible energy savings and utility impact if proposed systems were installed and operated in industrial plants. Detailed industrial process data, pertinent equipment technical and cost information, proposed plant advanced heat recovery/thermal energy storage system designs, and a complete discussion of the procedures used and the results obtained are presented.

  6. Toxicological effects of particulate emissions - A comparison of oil and wood fuels in small- and medium-scale heating systems

    NASA Astrophysics Data System (ADS)

    Kasurinen, Stefanie; Jalava, Pasi I.; Tapanainen, Maija; Uski, Oskari; Happo, Mikko S.; Mäki-Paakkanen, Jorma; Lamberg, Heikki; Koponen, Hanna; Nuutinen, Ilpo; Kortelainen, Miika; Jokiniemi, Jorma; Hirvonen, Maija-Riitta

    2015-02-01

    The use of wood instead of oil fuels in heating systems is strongly encouraged in many countries. Yet it is unknown to what extent such a large-scale change from oil to wood fuels in heating systems would contribute to any negative health effects from their emissions. We compared the toxicological properties of particulate matter (PM) emissions from wood and oil fuels from two small-scale and two medium-scale heating systems. To assess whether oil or wood combustion emissions cause adverse effects and which PM emissions' effects are more profound, we measured cell viability and proliferation, inflammatory markers, as well as DNA damage in RAW264.7 mouse macrophages. We found that the medium-scale oil-fueled heating system induced a dose-dependent increase of DNA damage, short-term cytotoxic effects, and a cell cycle arrest in the G2/M-phase. We did not detect an induction of DNA damage by the medium-scale wood-fired system. However, we detected significant short-term cytotoxicity. We found that both oil and wood combustion emission samples from the small-scale heating systems induced DNA damage. However, the short-term cytotoxic effects were greater for the PM emissions from the oil-fired heating system. PM mass emissions differed significantly between the tested heating systems. The lowest emissions, 0.1 mg/MJ, were produced by the small-scale oil-fired heating system; the highest emissions, 20.3 mg/MJ, by the medium-scale oil-fired heating system. The wood-fired heating systems' PM mass emissions were in between these concentrations, complicating the direct comparison of the emissions' health related toxic effects. Conclusively, our results indicate that the emissions from both the small- and the medium-scale wood-fueled heating systems cause overall less cytotoxicity and DNA damage in a cell model than the emissions from the corresponding oil-fueled heating systems. Hence, controlled wood-fueled heating systems may be good alternatives to heating systems fired with fuel oil.

  7. Heat recovery/thermal energy storage for energy conservation in food processing

    SciTech Connect

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

    1981-01-01

    Based on energy consumption data compiled for 1974, 59% of the total energy consumed in the US food processing industry was thermal energy. The energy-consuming processes which utilize this thermal energy reject significant quantities of waste heat, usually to the atmosphere or to the wastewater discharged from the plant. Design considerations for waste heat recovery systems in the food processing industry are discussed. A systematic analysis of the waste heat source, in terms of quantity and quality is explored. Other aspects of the waste heat source, such as contamination, are addressed as potential impediments to practical heat recovery. The characteristics of the recipient process which will utilize the recovered waste heat are discussed. Thermal energy storage, which can be used as a means of allowing the waste eat recovery process to operate independent of the subsequent utilization of the recovered energy, is discussed. The project included the design, installation and monitoring of two heat recovery systems in a Gold Kist broiler processing plant. These systems recover waste heat from a poultry scalder overflow (heated wastewater) and from a refrigeration condenser utilizing ammonia as the refrigerant. The performance and economic viability of the heat recovery systems are presented.

  8. Energy and exergy analysis of a latent heat storage system with phase change material for a solar collector

    Microsoft Academic Search

    Ahmet Koca; Hakan F. Oztop; Tansel Koyun; Yasin Varol

    2008-01-01

    Analysis of energy and exergy has been performed for a latent heat storage system with phase change material (PCM) for a flat-plate solar collector. CaCl2·6H2O was used as PCM in thermal energy storage (TES) system. The designed collector combines in single unit solar energy collection and storage. PCMs are stored in a storage tank, which is located under the collector.

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

    Microsoft Academic Search

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

    2003-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    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.

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

    PubMed Central

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

    2014-01-01

    Cultured epidermal cell sheets (CECS) are used in regenerative medicine in patients with burns, and have potential to treat limbal stem cell deficiency (LSCD), as demonstrated in animal models. Despite widespread use, short-term storage options for CECS are limited. Advantages of storage include: flexibility in scheduling surgery, reserve sheets for repeat operations, more opportunity for quality control, and improved transportation to allow wider distribution. Studies on storage of CECS have thus far focused on cryopreservation, whereas refrigeration is a convenient method commonly used for whole skin graft storage in burns clinics. It has been shown that preservation of viable cells using these methods is variable. This study evaluated the effect of different temperatures spanning 4°C to 37°C, on the cell viability, morphology, proliferation and metabolic status of CECS stored over a two week period in a xenobiotic–free system. Compared to non-stored control, best cell viability was obtained at 24°C (95.2±9.9%); reduced cell viability, at approximately 60%, was demonstrated at several of the temperatures (12°C, 28°C, 32°C and 37°C). Metabolic activity was significantly higher between 24°C and 37°C, where glucose, lactate, lactate/glucose ratios, and oxygen tension indicated increased activation of the glycolytic pathway under aerobic conditions. Preservation of morphology as shown by phase contrast and scanning electron micrographs was best at 12°C and 16°C. PCNA immunocytochemistry indicated that only 12°C and 20°C allowed maintenance of proliferative function at a similar level to non-stored control. In conclusion, results indicate that 12°C and 24°C merit further investigation as the prospective optimum temperature for short-term storage of cultured epidermal cell sheets. PMID:25170754

  12. Fabrication of High Anisotropy Nanoscale Patterned Magnetic Recording Medium for Data Storage Applications

    Microsoft Academic Search

    V. A. Parekh; D. Smith; A. Ruiz; J. C. Wolfe; P. Ruchhoeft; E. Svedberg; S. Khizroev; D. Litvinov

    2006-01-01

    Conventional magnetic recording systems based on continuous medium recording are rapidly approaching their superparamagnetic limit. A shift to patterned media, where the data are stored in arrays of discrete nanomagnets, will help extend the areal bit densities due to a significant increase in the thermal activation volume. One of the key challenges is the development of a cost-effective strategy for

  13. Thermal energy storage by means of reversible heat pumping utilizing industrial waste heat

    Microsoft Academic Search

    R. P. Cahn; E. W. Nicholson

    1978-01-01

    The invention discloses an improved process for storing the off-peak electrical output of an electricity generating plant in the form of heat by using the off-peak electrical output to raise the temperature level of a quantity of stored low vapor pressure thermal energy retention material and recalling the stored heat during periods of peak power demand in the form of

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

    Microsoft Academic Search

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

    2000-01-01

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

  15. Heat Transfer Analysis of Encapsulated Phase Change Materials for Thermal Energy Storage

    NASA Astrophysics Data System (ADS)

    Elmozughi, Ali F.

    Thermal analysis of high temperature phase change materials (PCMs) is conducted. Transient two dimensional heat transfer analysis is performed to investigate high temperature energy storage and retrieval for concentrated solar power applications. The phase change materials are considered are NaNO 3 and the eutectic of MgCl2 and NaCl. Phase change material is encapsulated by a stainless steel in a cylindrical shaped capsule. Energy storage/retrieval into/from various sizes of encapsulated phase change material (EPCM) capsules is simulated for both laminar and turbulent flow conditions of the heat transfer fluid (HTF) by an accurate modeling of the propagating liquid/solid interface in a PCM. Heat transfer inside EPCM capsule and the phase change of PCM are modeled by an enthalpy - porosity method. A two-dimensional cylindrical shaped EPCM capsule or tube is considered in simulations using gas (air) and liquid (Therminol/VP-1) as heat transfer fluids in a cross flow and an axial flow arrangement. The energy storage/retrieval times into/out of the EPCM capsule is dictated by the surface heat transfer of the EPCM for the capsule sizes considered in this study. A single horizontally placed rod in a channel with different blockage ratios for laminar and turbulence flows of HTF is studied in the present study. It is illustrated by the present work that enthalpy-porosity method can be applied to simulate heat transfer at the capsule level and the system level. System level storage module is a thermocline that includes an arrangement of several EPCMs for several megawatts of thermal energy storage (TES) for several hours used in concentrated solar power applications and other industrial thermal systems. Transport phenomena inside the EPCM are modeled accurately by considering a 20% air void and the buoyancy-driven convection in a stainless steel capsule. The effects of the thermal expansion and the volume expansion due to phase change on the energy storage and retrieval process are investigated. The charging and discharging into and from the capsule wall is simulated for different boundary conditions and is applied with both laminar and turbulent flow conditions. Computational models are conducted by applying an enthalpy -- porosity method and volume of fluid method (VOF) to calculate the transport phenomena within the PCM capsule, including an internal air void. Energy storage and retrieval in different sized capsules is simulated. A cylindrical shaped EPCM capsule or tube is considered in simulations using both gas (air) and liquid (Therminol/VP-1) as the heat transfer fluid in a cross flow arrangement. The presence of the void has profound effects on the thermal response of the EPCM during both energy storage and retrieval process. Melting and solidification per unit mass of the PCM takes longer when the void is present. Additionally, due to material properties and the lack of convective effects, the solidification process is much slower than the melting process. One of the most significant outcomes of the present work is that the thermal energy module in the power generation systems has to be designed properly by careful consideration of the heat transfer from HTF to the EPCM as well as the heat transport inside the EPCM.

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

    SciTech Connect

    Litzke, Wai-Lin

    1992-12-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Boockmeyer, Anke; Bauer, Sebastian

    2014-05-01

    Increasing use of energy stemming from renewable sources, such as wind or solar power plants, requires development of new and improvement of existing energy storage options on different time scales. One potential storage option is high temperature heat storage with temperatures of up to 100°C in the geological subsurface using borehole heat exchanger (BHE). Numerical scenario simulations are performed to assess feasibility and storage capacity and, furthermore, to predict the effects induced. To allow for accurate and reliable results, the BHE must be represented correctly and realistic in the numerical model. Therefore, a detailed model of a single BHE and the surrounding aquifer, accounting for the full geometry and component parametrisation (circulating working fluid, pipe and grout), is set up. This model setup is used to simulate an experimental data set from a laboratory sandbox by Beier et al. (2011), containing an 18 m long single U-tube BHE centered horizontally along it. Temperature curves observed in different radial distances as well as at the pipe outflow can be matched well with the model setup used, which is thus verified. Potential geological formations for high temperature heat storage are located in greater depths below fresh water aquifers that are used for drinking water. Therefore, the above model is adapted to represent a 100 m long vertical double U-tube BHE placed in an average depth of 500 m. The processes of heat transport and groundwater flow are coupled by water density and viscosity, which both depend on pressure and temperature. A sensitivity study is done to quantify the effects of the thermal parameters of grout and aquifer on the amount of heat stored and the temperature distribution in the aquifer. It was found that the amount of heat stored through the BHE is most sensitive to the heat conductivity of the aquifer. Increasing the aquifer heat conductivity by 50 % increases the amount of heat stored in the numerical model by 30 %. In contrast, only 3 % more heat can be stored in the system when increasing the grout thermal conductivity by 50 %. Temperature distribution in the aquifer is most sensitive to the thermal conductivity of the grout, resulting in higher temperatures when increasing the grout thermal conductivity. Increasing the aquifer thermal conductivity leads to higher temperatures at first and lower temperatures after a longer time period. Grout heat capacity, however, neither influences the amount of heat stored nor the temperature inside the aquifer. Occurrence and magnitude of the induced convection in the sand aquifer that surrounds the BHE depends on the given permeability as well as temperature gradients and therefore density differences in the model area. Increasing the vertical permeability from k=5×10-13 m2 to k=5×10-11 m2 results in induced convection with lower temperatures in the aquifer and a doubling of the amount of heat stored. Reference: R.A. Beier, M.D. Smith and J.D. Spitler. Reference data set for vertical borehole ground heat exchanger models and thermal response test analysis. Geothermics, 40, 79-85, (2011).

  18. Impact of Coupled Heat Transfer and Water Flow on Soil Borehole Thermal Energy Storage (SBTES) Systems: Experimental and Modeling Investigation

    NASA Astrophysics Data System (ADS)

    Moradi, A.; Smits, K. M.

    2014-12-01

    A promising energy storage option to compensate for daily and seasonal energy offsets is to inject and store heat generated from renewable energy sources (e.g. solar energy) in the ground, oftentimes referred to as soil borehole thermal energy storage (SBTES). Nonetheless in SBTES modeling efforts, it is widely recognized that the movement of water vapor is closely coupled to thermal processes. However, their mutual interactions are rarely considered in most soil water modeling efforts or in practical applications. The validation of numerical models that are designed to capture these processes is difficult due to the scarcity of experimental data, limiting the testing and refinement of heat and water transfer theories. A common assumption in most SBTES modeling approaches is to consider the soil as a purely conductive medium with constant hydraulic and thermal properties. However, this simplified approach can be improved upon by better understanding the coupled processes at play. Consequently, developing new modeling techniques along with suitable experimental tools to add more complexity in coupled processes has critical importance in obtaining necessary knowledge in efficient design and implementation of SBTES systems. The goal of this work is to better understand heat and mass transfer processes for SBTES. In this study, we implemented a fully coupled numerical model that solves for heat, liquid water and water vapor flux and allows for non-equilibrium liquid/gas phase change. This model was then used to investigate the influence of different hydraulic and thermal parameterizations on SBTES system efficiency. A two dimensional tank apparatus was used with a series of soil moisture, temperature and soil thermal properties sensors. Four experiments were performed with different test soils. Experimental results provide evidences of thermally induced moisture flow that was also confirmed by numerical results. Numerical results showed that for the test conditions applied here, moisture flow is more influenced by thermal gradients rather than hydraulic gradients. The results also demonstrate that convective fluxes are higher compared to conductive fluxes indicating that moisture flow has more contribution to the overall heat flux than conductive fluxes.

  19. Fundamental Properties of TBAF Clathrate for Usage as a Latent Heat Storage at a Room Temperature

    NASA Astrophysics Data System (ADS)

    Mizushima, Takanari; Kawamura, Hiroshi; Takao, Shingo; Yabe, Akira

    For promotion of further energy conservation, development of a coolant with a higher heat capacity regulated around a room temperature is strongly required. As a candidate of such a new coolant, we employ the clathrate hydrate, i.e., a mixture of Tetra n-butyl ammonium fluoride (TBAF) and water. This clathrate hydrate is composed of the micro crystals with an order of 100 ?m in dimension. It retains fluidity and melting point at a room temperature of about 25 °C. Moreover, the melting point is able to be controlled between 25 °C and 0 °C by changing the concentration of TBAF. The temperature can be regulated by its latent heat at the melting point. Characteristics such as the latent heat and the crystal structure of the clathrate have been experimentally obtained to confirm the feasibility for its usage as the latent heat storage around a room temperature.

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

    Microsoft Academic Search

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

    2001-01-01

    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

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

    NASA Technical Reports Server (NTRS)

    Holdsworth, David

    1996-01-01

    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.

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

    Microsoft Academic Search

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

    1998-01-01

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

  3. Stainless steel containers for the storage of low and medium level radioactive waste

    Microsoft Academic Search

    Leopold Vehovar; Marko Tandler

    2001-01-01

    Corrosion investigations have been performed on the austenitic structural steel AISI 304L, in comparison with the structural steel AISI 316L, in an aerated and a de-aerated solution, which was leached from low and medium level radioactive waste. On the basis of measured potentio-dynamic anodic polarization curves and the results of cyclic polarization tests, it was found that both types of

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

    SciTech Connect

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

    1986-05-01

    The heats of fusion of several fluoride salt mixtures with melting points greater than 973 K were estimated from a coupled analysis of the available thermodynamic data and phase diagrams. Simple binary eutectic systems with and without terminal solid solutions, binary eutectics with congruent melting intermediate phases, and ternary eutectic systems were considered. Several combinations of salts were identified, most notable the eutectics LiF-22CaF/sub 2/ and NaF-60MgF/sub 2/ which melt at 1039 and 1273 K respectively which posses relatively high heats of fusion/gm (greater than 0.7 kJ/g). Such systems would seemingly be ideal candidates for the light weight, high energy storage media required by the thermal energy storage unit in advanced solar dynamic power systems envisioned for the future space missions.

  5. Lithium Storage in Heat-Treated SnF2 /Polyacrylonitrile Anode.

    PubMed

    Shen, Lian; Shen, Lanyao; Wang, Zhaoxiang; Chen, Liquan

    2015-06-01

    Tin(II) fluoride (SnF2 ) has a high Li-storage capacity because it stores lithium first by a conversion reaction and then by a Li/Sn alloying/dealloying reaction. A polyacrylonitrile (PAN)-bound SnF2 electrode was heat-treated to enhance the integral electrical contact and the mechanical strength through its cross-linked framework. The heat-treated SnF2 electrode showed reversible capacities of 1047?mAh?g(-1) in the first cycle and 902?mAh?g(-1) after 100?cycles. Part of the excess capacity is due to lithium storage at the Sn/LiF interface, and the other part is assumed to correspond to the presence of reduced SnF2 with protons released during the thermal cross-linking of PAN. PMID:25925247

  6. Active heat exchange system development for latent heat thermal energy storage

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

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

  7. Numerical simulation of porous latent heat thermal energy storage for thermoelectric cooling

    Microsoft Academic Search

    Juan P. Trelles; John J. Dufly

    2003-01-01

    Porous latent heat thermal energy storage for thermoelectric cooling is simulated via a matrix-based enthalpy formulation, having the temperature as unknown, in a three-dimensional domain. The system is made up of two aluminum containers; the inner one contains the cooling objective in water suspension and the outer one the phase change material (PCM) in a porous aluminum matrix. The system’s

  8. High latent heat storage and high thermal conductive phase change materials using exfoliated graphite nanoplatelets

    Microsoft Academic Search

    Sumin Kim; Lawrence T. Drzal

    2009-01-01

    Using exfoliated graphite nanoplatelets (xGnP), paraffin\\/xGnP composite phase change materials (PCMs) were prepared by the stirring of xGnP in liquid paraffin for high electric conductivity, thermal conductivity and latent heat storage. xGnP of 1, 2, 3, 5 and 7wt% was added to pure paraffin at 75°C. Scanning electron microscopy (SEM) morphology showed uniform dispersion of xGnP in the paraffin wax.

  9. Preparation and properties of shape-stabilized heat storage phase change materials in solar greenhouse

    Microsoft Academic Search

    Chen Minghui; Cheng Liyuan; Ma Feng; Liu Leili

    2011-01-01

    Octadecane-lauric acid\\/expanded graphite shape- stabilized phase change materials (OC-LA\\/EG), which is suitable to heat storage for solar greenhouse production, were prepared by using the eutectic mixture of octadecane (OC) and lauric acid (LA) as phase change material, porous expanded graphite (EG) of high adsorption characteristics as supporting matrix. The structure and properties of the materials were studied by ESEM, DSC

  10. Preparation and properties of gypsum-based heat storage and preservation material

    Microsoft Academic Search

    Min Li; Zhishen Wu; Meirong Chen

    2011-01-01

    The paraffin\\/expanded perlite shape-stabilized phase change material (PCM) was prepared by absorbing paraffin into pores of expanded perlite with vacuum adsorption method (VA method). The gypsum-based heat storage and preservation material was prepared by mixing the prepared paraffin\\/expanded perlite shape-stabilized PCM and gypsum. Scanning electron microscopy (SEM) was used to investigate the influence of the VA method and free adsorption

  11. Capric Acid and Myristic Acid for Latent Heat Thermal Energy Storage

    Microsoft Academic Search

    A. Sari; A. Karaipekli; K. Kaygusuz

    2008-01-01

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

  12. Thermal Characteristics of Paraffin\\/Expanded Perlite Composite for Latent Heat Thermal Energy Storage

    Microsoft Academic Search

    A. Kara?pekl?; A. Sar?; K. Kaygusuz

    2009-01-01

    This study focuses on the preparation and thermal properties of paraffin\\/expanded perlite composite as novel form-stable phase change material for latent heat thermal energy storage by vacuum impregnation method. The paraffin could be absorbed in pores of expanded perlite as much as 55 wt% without melted phase change material seepage from the composite and this mixture was described as form-stable

  13. A direct-heating energy-storage receiver for dish-Stirling solar energy systems

    SciTech Connect

    Lund, K.O. [Univ. of California, La Jolla, CA (United States)

    1996-02-01

    Dish-Stirling solar receiver designs are investigated and evaluated for possible use with sensible energy storage in single-phase materials. The designs differ from previous receivers in utilizing axial conduction in the storage material for attenuation of the solar flux transients due to intermittent cloud cover, and in having convective heat removal at the base of the receiver. One-dimensional, time-dependent heat transfer equations are formulated for the storage material temperature field, including losses to the environment, and a general heat exchange effectiveness boundary condition at the base. The solar source flux is represented as the sum of steady and periodic cloud-transient components, with the steady component solved subject to specified receiver thermal efficiency. For the transient cloud-cover component the Fast Fourier Transform algorithm (FFT) is applied, and the complex transfer function of the receiver is obtained as a filter for the input flux spectrum. Inverse transformation results in the amplitudes and mode shapes of the transient temperature component. By adjustment of design parameters, the cloud-cover amplitude variations of the outlet gas temperature can be limited to acceptable magnitudes, thus simplifying control systems.

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

    DOEpatents

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

    1981-04-21

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

    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.

  16. Migration of bisphenol A from can coatings--effects of damage, storage conditions and heating.

    PubMed

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

    2004-10-01

    Bisphenol A (BPA) is an important monomer used in the manufacture of epoxy resins for internal food can linings. Experiments were conducted to investigate the effects of different storage conditions and can damage on the migration of BPA to foods. These experiments were conducted in a systematic fashion by filling empty epoxyphenolic coated cans with four foods: soup, minced beef, evaporated milk and carrots and a food simulant (10% ethanol). Filled cans of each food type or simulant were then sealed and processed using appropriate conditions, before storage at three different temperatures: 5 degrees C, 20 degrees C and 40 degrees C. For each of the storage regimes, 50% of the cans were dented to establish if this would lead to increased BPA migration. Cans were removed from these stocks at intervals of 1, 3 and 9 months storage at 5 degrees C and 20 degrees C or 10 days, 1 and 3 months at 40 degrees C. Some initial problems of heterogeneity between samples was overcome by determining the amount of BPA in food as well as in the can lining. It was found that 80-100% of the total BPA present in the coating had migrated to foods directly after can processing by pilot plant filling with food or simulant, sealing and sterilization. This level was not changed by extended storage (up to 9 months) or can damage, indicating most migration was occurring during the can processing step. There was no noticeable difference, in this respect, between the different foods or the food simulant. Analysis of control samples (foods fortified with approximately 0.1 mg kg(-1) BPA and contained in Schott bottles) showed that BPA was stable under both processing and storage. Experiments were also conducted to investigate the potential effects, on the migration of BPA from can coatings, of cooking or heating foods in the can prior to consumption. Food cans were purchased and the food either cooked or heated in the can. BPA was analysed prior to and after the heating/cooking process. It was concluded from the results that there were no appreciable differences in the BPA level before and after cooking or heating. PMID:15712526

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

    Microsoft Academic Search

    Qi Qi; Yiqiang Jiang; Shiming Deng

    2008-01-01

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

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

    E-print Network

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

    2013-01-01

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

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

    SciTech Connect

    Parker, J.C.

    1981-04-01

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

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

    Microsoft Academic Search

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

    1996-01-01

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

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

    Microsoft Academic Search

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

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

    Microsoft Academic Search

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

    2010-01-01

    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

  3. Medium tumor antigen of polyomavirus transformation-defective mutant NG59 is associated with 73-kilodalton heat shock protein.

    PubMed Central

    Walter, G; Carbone, A; Welch, W J

    1987-01-01

    Affinity-purified medium T antigen encoded by NG59, a nontransforming mutant of polyomavirus, is specifically associated with a protein of 72,000 daltons (72K protein). Medium T antigens of wild-type polyomavirus and the transformation-competent mutant dl8 are not associated with the 72K protein. Instead, they form a complex with another protein of 61,000 daltons. Several lines of evidence suggest that the medium T antigen-associated 72K protein is equivalent to the abundant and constitutive 73K heat shock protein. First, on two-dimensional polyacrylamide gels the 72K protein migrated with the same pI (5.6) as did the 73K heat shock protein. Second, the 72K protein was immunoprecipitable with antibodies against heat shock proteins. Third, when digested with V8 protease, the 72K protein gave rise to the same pattern of fragments as did the 73K heat shock protein. Images PMID:3027370

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

    PubMed

    Lubaretz, Olga; Zur Nieden, Uta

    2002-06-01

    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

  5. Heat storage in the Hettangian aquifer in Berlin - results from a column experiment

    NASA Astrophysics Data System (ADS)

    Milkus, Chri(Sch)augott

    2015-04-01

    Aquifer Thermal Energy Storage (ATES) is a sustainable alternative for storage and seasonal availability of thermal energy. However, its impact on the subsurface flow regime is not well known. In Berlin (Germany), the Jurassic (Hettangian) sandstone aquifer with highly mineralized groundwater (TDS 27 g/L) is currently used for heat storage. The aim of this study was to examine the hydrogeochemical changes that are caused by the induced temperature shift and its effects on the hydraulic permeability of the aquifer. Column experiments were conducted, in which stainless steel columns were filled with sediment from the aquifer and flushed with native groundwater for several weeks. The initial temperature of the experiment was 20°C, comparable to the in-situ conditions within the aquifer. After reaching equilibrium between sediment and water, the temperature was increased to simulate heating of the aquifer. During the experiment, physical and chemical parameters (pH, ORP, dissolved oxygen and dissolved carbon dioxide) were measured at the outflow of the column and the effluent water was sampled. Using a Scanning Electron Microscope, the deposition of precipitated minerals and biofilm on sediment grains was analyzed. Changes in hydraulic properties of the sediment were studied by the use of tracer tests with Uranin.

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

    NASA Astrophysics Data System (ADS)

    Roux, Nicolas; Grenier, Christophe; Costard, François

    2015-04-01

    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. The feedback induced by such changes on permafrost degradation is still not clearly assessed. Of particular interest are lake and river's taliks. A talik is a permanently unfrozen zone that lies below rivers or lakes. They are likely to play a key role in the formerly presented interactions, given that they are the only paths for groundwater flow in permafrost regions. Thus heat transfers on a regional scale are influenced by groundwater circulation. The aim of our study is therefore to investigate the evolution of river's taliks. In addition, they are the only perennial liquid water resources in continuous permafrost environments. The issue associated is to what extent can taliks develop into the future because of climate change and how likely are they to become open taliks, connecting sub-permafrost water with surface water with potentially strong geochemical changes? We developed a multidisciplinary approach coupling field investigation, experimental studies in a cold room and numerical modeling. The field investigation concerns Central Yakutia, Siberia, where we have installed instruments to monitor ground temperatures and water pressure in a small river's talik between two thermokarst lakes. We present here the results corresponding to the cold room experimental work, associating numerical modeling and laboratory experiments in order to look after the main parameters controlling river's talik installation and validate our numerical simulation approach. In a cold room at GEOPS, where a metric scale channel is filled with a porous medium (sand or silty-clay), we are able to control air, water and permafrost initial temperature, but also water flow. At initial time, the "river" water flow is started. The progression of the thawing front is monitored by an array of thermal sensors. A sensitivity study involving water flow rates and temperatures is carried on, so that we can test various parameter sets for a miniaturized river. Main thaw propagation controlling parameters are identified. These results are then confronted with a numerical model developed at the LSCE with Cast3m (www-cast3m.cea.fr). Various expressions for river-talik heat exchange terms are tested and the simulations are confronted with the experimental data. Main results are presented as well as the baseline to deal with the field conditions in Siberia based on the present study. Keywords: Talik, River, Numerical Modeling, Cold Room, Permafrost.

  7. An Example:-Control of Blood Glucose Glucose in Body Cells is Stored in Medium-Term Storage (Fat, Long-Term; ATP and

    E-print Network

    Cutler, Chris

    An Example:- Control of Blood Glucose Glucose in Body Cells is Stored in Medium-Term Storage (Fat, Long-Term; ATP and Creatine Phosphate, Short-Term) ______________, a Branched Glucose Polymer Glycogen (by Pancreatic Beta Cells) to Lower Blood Glucose to a Normal Level After Meals When Blood Glucose

  8. Long-term survival of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis as isolates and in nasopharyngeal specimens in frozen STGG storage medium.

    PubMed

    Kaijalainen, Tarja; Palmu, Arto

    2015-07-01

    We evaluated survival in WHO-recommended STGG storage medium of bacteria causing respiratory-tract infection. Streptococcus pneumoniae and Moraxella catarrhalis survived as single and mixed isolates stored at -70°C for 12.5years, but Haemophilus influenzae less than 4years. All the bacteria survived in the nasopharyngeal specimens at -70°C for 11years. PMID:25937246

  9. Energy storage using phase-change materials for active solar heating and cooling: An evaluation of future research and development direction

    Microsoft Academic Search

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

    1982-01-01

    The current state of the art and commercial potential of active solar heating and cooling systems for buildings, and the use of thermal energy storage with these systems are assessed. The need for advanced latent heat storage subsystems in these applications and priorities for their development are determined. Latent storage subsystems are advantageous in applications where their compactness may be

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

    SciTech Connect

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

    2008-12-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    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.

  12. Suitability of the CASES software for evaluation of district heating systems based on annual storage cycles

    SciTech Connect

    Calm, J.M.; Sapienza, G.R.

    1980-07-01

    The CASES computer program is a software package for evaluation of community annual-storage energy system concepts. The software models energy systems that provide space and water heating by cascaded heat pumps and cooling by melting of stored ice. CASES computes thermal demands of individual buildings, aggregates these demands into community demands, models system response, and estimates the overall system costs. The Heat-Pump-Centered Integrated Community Energy Systems (HP-ICES) Project has produced a number of system concepts involving annual-storage cycles for which preliminary application feasibility studies have been performed. More rigorous examination of these concepts as well as detailed simulation and analysis of application feasibility would increase understanding of their potential. The CASES software was considered for these purposes, but was found unsuitable for evaluation of HP-ICES concepts and their application feasibility. No alternative software has been identified which will provide these capabilities, and extensive effort would be required to upgrade CASES for the intended concept evaluations.

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

    SciTech Connect

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

    1988-04-01

    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.

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

    Microsoft Academic Search

    J. S. Francetic; K. S. Robinson

    1987-01-01

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

  15. Thermal storage in ammonium alum/ammonium nitrate eutectic for solar space heating

    SciTech Connect

    Goswami, D.Y.; Jotshi, C.K.; Klausner, J.F.; Hsieh, C.K.; Srinivasan, N. [Univ. of Florida, Gainesville, FL (United States). Dept. of Mechanical Engineering

    1995-10-01

    Ammonium alum and ammonium nitrate in the weight ratio of 1:1 forms a eutectic that melts at 53 C and crystallizes at 48 C. The latent heat of fusion of this eutectic was found to be 215 kJ/kg. Its enthalpy as measured by drop calorimetry was found to be 287 kJ/kg in the temperature range of 24--65 C, which is 1.67 times greater than water (172.2 kJ/kg) and 8.75 times greater than rock (32.8 kJ/kg). Upon several heating/cooling cycles, phase separation was observed. However, by adding 5% attapulgite clay to this eutectic mixture, phase separation was prevented. This eutectic was encapsulated in 0.0254m diameter HDPE hollow balls and subjected to about 1,100 heating/cooling cycles in the temperature range between 25 and 65 C. At the end of these cycles, the decrease in enthalpy was found to be 5%. A scale model of the heat storage unit was fabricated to investigate the heat transfer characteristics of this eutectic encapsulated in HDPE balls. The thermal extraction efficiency of the system was measured with the recirculation of hot air during charging and was found to be in the range of 85--98%.

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    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.

  18. Study of an Optical Non-Contact Measurement Technique of the Solidification Rate for Latent Heat-Storage Materials

    NASA Astrophysics Data System (ADS)

    Tanaka, Takahiro; Kudo, Kazuhiko

    A new technique is developed for the measurement of the solidification rate for a latent-heat storage material that consisted of spherical n-paraffin particles and water (emulsion slurry). This method utilizes the correlation between the optical characteristics of the slurry and the solidification rate of the paraffin particles. From experiment, it was shown that the increase in the solidification rate of the particles causes the rise in the transimissivity and the drop in the reflectivity of the slurry. Each paraffin particles has a conical crater on the surface when it solidifies. Based on these observations, a new radiative transfer model has been developed for a transparent particle with a conical crater and a three-dimensional radiative transfer model for a particulate medium by the Monte Carlo method. The analytical results for the slurry using the model well agreed with the experimental ones. From the analysis, it was shown that the crater on the particle surface makes the forward scattering weak and scattering in the backward and the lateral direction strong. Therefore, it was concluded that the rise in the transmissivity and decrease in the reflectivity of the slurry by the increase in its solidification rate is caused by the craters on the particle surfaces due to their phase-change.

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

    NASA Technical Reports Server (NTRS)

    Namkoong, D.

    1976-01-01

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

  20. Capric acid and palmitic acid eutectic mixture applied in building wallboard for latent heat thermal ener gy storage

    Microsoft Academic Search

    Ali Karaipekli; Ahmet Sari

    TES medium, which can be applied to peak load shifting, improved use of waste heat and solar ener gy as well as more ef ficient operation of heating and cooling equipment. In addition, PCW has good thermal reliability in terms of the changes in its thermal properties after accelerated 1000, 2000, 3000, 4000, and 5000 thermal cycling. Use of such

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

    PubMed

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

    2012-03-01

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

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

    SciTech Connect

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

    1991-10-01

    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.

  3. Numerical analysis of the thermal behaviour of a shell-and-tube heat storage unit using phase change materials

    Microsoft Academic Search

    Hamid Ait Adine; Hamid El Qarnia

    2009-01-01

    This work presents a numerical study of a latent heat storage unit (LHSU) consisting of a shell-and-tube. The shell space is filled with two phase change materials (PCMs), P116 and n-octadecane, with different melting temperatures (50°C and 27.7°C, respectively). A heat transfer fluid (HTF: water) flows by forced convection through the inner tube, and transfers the heat to PCMs. In

  4. Second law optimization of a sensible heat thermal energy storage system with a distributed storage element. Part 2; Presentation and interpretation of results

    Microsoft Academic Search

    M. J. Taylor; R. J. Krane; J. R. Parsons

    1991-01-01

    This paper explores the behavior of a flat- slab, sensible heat thermal energy storage system, the physical design and operation of which have been optimized to minimize the production of entropy by thermodynamic irreversibilities. This part includes a description of the numerical model and the presentation and interpretation of the results of a system optimization study. The major results of

  5. Thermal energy storage material thermophysical property measurement and heat transfer impact

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

    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.

  6. High temperature thermal energy storage in moving sand

    Microsoft Academic Search

    R. H. Turner; H. I. Awaya

    1978-01-01

    Several high-temperature (to 500 C) heat-storage systems using sand as the storage medium are described. The advantages of sand as a storage medium include low cost for sand, widespread availability, non-toxicity, non-degradation characteristics, easy containment, and safety. The systems considered include: stationary sand with closely spaced tubes throughout the volume, the use of a fluidized bed, use of conveyor belt

  7. Studies of velocity fields in a water heat storage with a video based particle tracking velocimetry technique

    SciTech Connect

    Dahl, J.; Hermansson, R.; Veber, P. [Luleaa Univ. of Technology (Sweden). Division of Energy Engineering

    1995-12-31

    Thermal storage in water has become very common in the last decades in many countries. Short term water heat storage systems play an important role in combined heat and power plants, in the process industry, in solar thermal systems and for domestic hot water production. The water volume must be thermally stratified to avoid degradation of heat quality. The temperature distribution in the storage is, however, the integrated result of a complicated process where many different phenomena act together. Temperature measurements only will not be sufficient to explain and evaluate the thermal behavior of a storage system; increased knowledge about the velocity field is needed. A video based Particle Tracking Velocimetry technique has been developed and used to document the non-stationary velocity field in a water heat storage system. An ordinary video camera is used to record the in-plane movements of particles in a light sheet in seeded water. The technique offers a powerful method for studies of fluid flow and velocity field. The combination of particle traces and vector plots have proven to be an efficient tool in gaining knowledge about crucial phenomena. Velocity fields are presented, showing mixing near the inlet, natural convection at the wall and exchange of water between the boundary layer and the core, and their impact on the stratification in the storage.

  8. Transient thermal analysis of three fast-charging latent heat storage configurations for a space-based power system

    SciTech Connect

    Stovall, T.K.; Arimilli, R.V.

    1988-01-01

    A space-based thermal storage application must accept large quantities of heat in a short period of time at an elevated temperature. A model of a lithium hydride phase change energy storage system was used to estimate reasonable physical dimensions for this application which included the use of a liquid metal heat transfer fluid. A finite difference computer code was developed and used to evaluate three methods of enhancing heat transfer in the PCM energy storage system. None of these three methods, inserting thin fins, reticulated nickel, or liquid lithium, significantly improved the system performance. The use of a 95% void fraction reticulated nickel insert was found to increase the storage capacity (total energy stored) of the system slightly with only a small decrease in the system energy density (energy storage/system mass). The addition of 10% liquid lithium was found to cause minor increases in both storage density and storage capacity with the added benefit of reducing the hydrogen pressure of the lithium hydride. 9 refs., 7 figs., 2 tabs.

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

    SciTech Connect

    Hall, C.A. III; Glakpe, E.K.; Cannon, J.N. [Howard Univ., Washington, DC (United States). School of Engineering; Kerslake, T.W. [NASA Lewis Research Center, Cleveland, OH (United States)

    1997-12-31

    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 heat receiver component of NASA Lewis Research Center`s Ground Test Demonstration (GTD) project was developed. Multi-conjugate effects such as the convective fluid flow of a low-Prandtl-number fluid, coupled with thermal conduction in the phase change material, containment tube and working fluid conduit were accounted for in the model. A single-band thermal radiation model was also included to quantify reradiative energy exchange inside the receiver and losses through the aperture. The eutectic LiF-CaF{sub 2} was used as the phase change material (PCM) and a mixture of He/Xe was used as the working fluid coolant. A modified version of the computer code HOTTube was used to generate results in the two-phase regime. Results indicate that parametric changes in receiver gas inlet temperature and receiver heat input effects higher sensitivity to changes in receiver gas exit temperatures.

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

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Mukka, Santosh K.; Rahman, Muhammad M.

    2004-02-01

    This paper presents a systematic analysis of fluid flow and heat transfer in a liquid hydrogen storage vessel for both earth and space applications. The study considered a cylindrical tank with elliptical top and bottom. The tank wall is made of aluminum and a multi-layered blanket of cryogenic insulation (MLI) has been attached on the top of the aluminum. The tank is connected to a cryocooler to dissipate the heat leak through the insulation and tank wall into the fluid within the tank. The cryocooler has not been modeled; only the flow in and out of the tank to the cryocooler system has been included. The primary emphasis of this research has been the fluid circulation within the tank for different fluid distribution scenario and for different level of gravity to simulate potential earth and space based applications. The equations solved in the liquid region included the conservation of mass, conservation of energy, and conservation of momentum. For the solid region only the heat conduction equation was solved. The steady-state velocity, temperature, and pressure distributions were calculated for different inlet positions, inlet velocities, and for different gravity values. The above simulations were carried out for constant heat flux and constant wall temperature cases. It was observed that a good flow circulation could be obtained when the cold entering fluid was made to flow in radial direction and the inlet opening was placed close to the tank wall.

  12. Thermal storage in ammonium alum/ammonium nitrate eutectic for solar space heating applications

    SciTech Connect

    Jotshi, C.K.; Hsieh, C.K.; Goswami, D.Y.; Klausner, J.F.; Srinivasan, N. [Univ. of Florida, Gainesville, FL (United States). Dept. of Mechanical Engineering

    1998-02-01

    Ammonium alum and ammonium nitrate in the weight ratio of 1:1 form a eutectic that melts at 53 C and solidifies at 48 C. The thermophysical properties of this eutectic were measured in detail and the eutectic was found to have properties desirable for energy storage for solar space heating applications. The eutectic was encapsulated in 0.0254-m diameter high-density polyethylene (HDPE) balls and packed into a cylindrical bed in a scale model for testing its heat transfer characteristics when exposed to an air flow. Test results indicate that the thermal extraction efficiency of the model was 89% with an uncertainty of {+-} 8.0%. The packed bed had a Stanton number value in close agreement with that predicted with an empirical equation for sensible heat extraction from the eutectic in the solid phase. This Stanton number was increased by about 74% for sensible heat extraction from the eutectic in the liquid phase, a phenomenon not previously reported in the literature.

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

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

    SciTech Connect

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

    2012-01-01

    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.

  15. Self-pressurization of a flightweight liquid hydrogen storage tank subjected to low heat flux

    NASA Technical Reports Server (NTRS)

    Hasan, M. M.; Lin, C. S.; Vandresar, N. T.

    1991-01-01

    Results are presented for an experimental investigation of self-pressurization and thermal stratification of a 4.89 cu m liquid hydrogen (LH2) storage tank subjected to low heat flux (0.35, 2.0, and 3.5 W/sq m) under normal gravity conditions. Tests were performed at fill levels of 83 to 84 percent (by volume). The LH2 tank was representative of future spacecraft tankage, having a low mass-to-volume ratio and high performance multilayer thermal insulation. Results show that the pressure rise rate and thermal stratification increase with increasing heat flux. At the lowest heat flux, the pressure rise rate is comparable to the homogenous rate, while at the highest heat flux, the rate is more than three times the homogeneous rate. It was found that initial conditions have a significant impact on the initial pressure rise rate. The quasi-steady pressure rise rates are nearly independent of the initial condition after an initial transient period has passed.

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

    SciTech Connect

    Wildin, M.W.

    1983-01-01

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

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

    SciTech Connect

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

    2011-07-14

    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.

  18. Studies on split heat pipe type adsorption ice-making test unit for fishing boats: Choice of heat pipe medium and experiments under unsteady heating sources

    Microsoft Academic Search

    L. W. Wang; R. Z. Wang; Z. S. Lu; C. J. Chen

    2006-01-01

    The split heat pipe type compound adsorption ice maker for fishing boats not only has the advantage of large volume cooling density but also has the advantage of less power consumption and high heat transfer performance. The available heat pipe media for the split heat pipe type compound adsorption ice maker, which are methanol, acetone and water are studied and

  19. A low-temperature heat storage system utilizing mixtures of magnesium salt hydrates and ammonium nitrate

    SciTech Connect

    Vaccarino, C.; Barbaccia, A.; Frusteri, F.; Galli, G.; Maisano, G.

    1985-02-01

    The heat storage system based on mixtures of salt hydrates and anhydrous salts desjribed in previous articles has been applied to Mg(NO/sub 3/)/sub 2/.6H/sub 2/O and MgCI/sub 2/. 6H/sub 2/O (alone or in eutectic mixtures), added with NH/sub 4/NO/sub 3/. Calorimetric measurements showed that in the temperature range 25-60/sup 0/C, Mg(NO/sub 3/). 6H/sub 2/O allows a Thermal Energy Storage (TES) capacity of about 56 kcal/kg (equivalent to 86 kcal/liter), which is slightly lower than the values previously recorded with ammonium alum. When the maximum temperature was lowered to 55/sup 0/ and to 50/sup 0/C, in order to be closer to the peak-efficiency of commercial flat-plate collectors, the best results were obtained, respectively, with Mg(NO/sub 3/)/sub 2/ .6H/sub 2/O and with the eutectic mixture Mg(NO/sub 3/)/sub 2/. 6H/sub 2/O - MgCI/sub 2/. 6H/sub 2/O, both added with NH/sub 4/NO/sub 3/. The mixtures of the aforementioned magnesium salts and ammonium nitrate do not show any significant efficiency reduction after many thermal cycles, and at the present stage of the research, they may be considered the most suitable for obtaining heat storages in the temperature range of commercial solar collectors.

  20. Experimental investigations of the performance of a solar air collector with latent heat thermal storage integrated with the solar absorber

    NASA Astrophysics Data System (ADS)

    Charvat, P.; Pech, O.; Hejcik, J.

    2013-04-01

    The paper deals with experimental investigations of the performance of a solar air collector with latent heat thermal storage integrated with the solarabsorber. The main purpose of heat storage in solar thermal systems is to store heat when the supply of solar heat exceeds demand and release it when otherwise. A number of heat storage materials can be used for this purpose; the phase change materials among them. Short-term latent heat thermal storage integrated with the solar absorber can stabilize the air temperature at the outlet of the collector on cloudy days when solar radiation intensity incident on a solar collector fluctuates significantly. Two experimental front-and-back pass solar air collectors of the same dimensions have been built for the experimental investigations. One collector had a "conventional" solar absorber made of a metal sheet while the solar absorber of the other collector consisted of containers filled with organic phase change material. The experimental collectors were positioned side by side during the investigations to ensure the same operating conditions (incident solar radiation, outdoor temperature).

  1. Astaxanthin present in the maturation medium reduces negative effects of heat shock on the developmental competence of porcine oocytes.

    PubMed

    Do, Lanh Thi Kim; Luu, Vien Viet; Morita, Yasuhiro; Taniguchi, Masayasu; Nii, Masahiro; Peter, Augustine T; Otoi, Takeshige

    2015-06-01

    Astaxanthin, one of the most common carotenoids, elicits antioxidant effects on cellular viability and embryonic development. This study was conducted to investigate the effects of astaxanthin on maturation, fertilization and development of porcine oocytes matured in vitro under heat stress conditions, and then fertilized and cultured under standard conditions. Porcine oocytes were cultured in maturation medium supplemented with different concentrations of astaxanthin (0, 0.25, 0.5 or 1ppm) for 46h at either 38.5 or 41°C. In comparison to oocytes cultured at 38.5°C, the exposure of porcine oocytes to 41.0°C during in vitro maturation (IVM) significantly inhibited maturation and development of fertilized oocytes to the blastocyst stage. Supplementation of maturation medium with astaxanthin (0.5ppm) significantly improved oocyte maturation, fertilization and development to the blastocysts stage in both oocyte groups. However, the total cell number and apoptosis index of blastocysts did not differ among groups. Moreover, astaxanthin (0.5ppm) significantly increased the rate of oocytes that reached metaphase II and decreased proportion of apoptotic oocytes exposed to H2O2 (1.0mM) during IVM. In summary, we demonstrated that supplementation of maturation medium with astaxanthin (0.5ppm) exerted antioxidative effects and improved the ability of maturation, fertilization, and development of porcine oocytes exposed to heat stress. PMID:26051456

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

    SciTech Connect

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

    2004-07-01

    The experimental data of investigation into low energy nuclear reactions (LERN) in condensed media are presented. The nuclear reactions products were researched in the solid cathode medium of a glow discharge. Hypothetically the nuclear reactions were initiated when bombarding the cathode surface by plasma ions with the energy of 1.0-2.0 keV. The results on recording excess heat power under the experiments with a high-current glow discharge in D{sub 2}, Xe and Kr, when using preliminary deuterium-charged Pd and Ti cathode samples are given. The excess heat power up to 10-15 W and efficiency up to 150 % was recorded under the experiments for Pd cathode samples in D{sub 2} discharge. The excess heat power up to 5 W and efficiency up to 150 % was recorded for the preliminary deuterium-charged Pd cathode samples in Xe and Kr discharges. At the same time the excess heat power was not observed for pure Pd cathode samples in Xe, Kr discharges. Forming the impurity nuclides ({sup 7}Li, {sup 13}C, {sup 15}N, {sup 20}Ne, {sup 29}Si, {sup 44}Ca, {sup 48}Ca, {sup 56}Fe, {sup 57}Fe, {sup 59}Co, {sup 64}Zn, {sup 66}Zn, {sup 75}As, {sup 107}Ag, {sup 109}Ag, {sup 110}Cg, {sup 111}Cg, {sup 112}Cg, {sup 114}Cg, {sup 115}In) with the efficiency up to 10{sup 13} atoms/s was recorded. Large deviation of the registered isotopes relation from the natural relation of these elements isotopes was observed. The soft X-ray radiation from the solid-state cathode medium with the intensity up to 0.01 Gy/s was recorded under the experiments with the discharge in H{sub 2}, D{sub 2}, Ar, Xe, Kr. The X-ray radiation was observed as bursts (up to 10{sup 6} photons in a burst and up to 10{sup 5} bursts a second) during the discharge burning and within 100 ms after turning off the discharge current. The results of the X-ray radiation registration showed that the exited energy levels having the lifetime up to 100 ms and more and the energy of 1.2 - 1.8 keV existed in the solid medium. The possible mechanism of producing the excess heat power and products of nuclear transmutation reactions in the solid medium with the exited energy levels was considered. (author)

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

    Microsoft Academic Search

    M. Cheralathan; R. Velraj; S. Renganarayanan

    2006-01-01

    This work investigates the transient behaviour of a phase change material based cool thermal energy storage (CTES) system\\u000a comprised of a cylindrical storage tank filled with encapsulated phase change materials (PCMs) in spherical container integrated\\u000a with an ethylene glycol chiller plant. A simulation program was developed to evaluate the temperature histories of the heat\\u000a transfer fluid (HTF) and the phase

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

    SciTech Connect

    Hardy, B

    2007-11-16

    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.

  5. Osmotic Dehydration of Apple Cylinders: III. Continuous Medium Flow Microwave Heating Conditions

    Microsoft Academic Search

    Heping Li; Hosahalli S. Ramaswamy

    2006-01-01

    Continuous flow osmotic drying permits a better exchange of moisture and solids between the food particle and osmotic solution than the batch process. Osmotic drying has been well studied by several researchers mostly in the batch mode. Microwave heating has been traditionally recognized to provide rapid heating conditions. Its role in the finish drying of food products has also been

  6. Heat transfer model for unprotected steel members in a standard compartment fire with participating medium

    Microsoft Academic Search

    J. I. Ghojel; M. B. Wong

    2005-01-01

    A heat transfer model accounting for the radiative properties of combustion products in a compartment standard fire is presented. The model used is based on a conceptual scheme of a grey gas mixture exchanging radiative energy with a black enclosure. The proposed model, with a radiation heat transfer that accounts for the effect of combustion products on the rate of

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

    NASA Astrophysics Data System (ADS)

    Furutani, Hirohide; Uzunow, Nikolaj

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

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

    E-print Network

    Brough, Joan

    1988-01-01

    EFFECTS OF NaCl, SUCROSE, AND STORAGE ON RHEOLOGICAL PARAMETERS OF HEAT INDUCED GELS OF LIQUID EGG PRODUCTS A Thesis by Joan Brough Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... and content by: C. W. Dill (Chair of Committee) F. A. Gardner (Member) R. L. Edwards (Member) G. C. Smith (Head of Department) December 1988 ABSTRACT Effects of NaC1, Sucrose, and Storage on Rheological Parameters of Heat Induced Gels of Liquid Egg...

  9. Evaluation of the heat-storage capability of shallow aquifers using active heat tracer tests and Fiber-Optics Distributed-Temperature-Sensing

    NASA Astrophysics Data System (ADS)

    Suibert Oskar Seibertz, Klodwig; Chirila, Marian Andrei; Bumberger, Jan; Dietrich, Peter; Vienken, Thomas

    2015-04-01

    In the course of the energy transition, geothermal energy storage and heat generation and cooling have proven to be environmental friendly alternatives to conventional energy. However, to ensure sustain usage, the heat transport behavior of aquifers and its distribution has to be studied. A tool to achieve this is the active heat tracer test, eg. Leaf et al. (2012). If active heat tracer tests are combined with in aquifer heat testing via electric heating-cables, eg. Liu et al. (2013), it is possible to observe heat transport and temperature signal decay without disturbing the original pressure field within the aquifer. In this field study a two channel High-Resolution-Fiber-Optic-Distributed-Temperature-Sensing and Pt100 were used to measure temperature signals within in two wells of 1.4 m distance, where the temperature difference was generated using a self regulating heating cable in the upstream well. High resolution Distributed-Temperature-Sensing measurements were achieved by coiling the fiber around screened plastic tubes. The upstream well was also used to observe heating (? Tmax approx. 24K) and temperature signal decay, while the downstream well was used to observe heat transport between both wells. The data was analyzed and compared to thermal conductivity of soil samples and Direct-Push (DP) Electrical-Conductivity-Logging and DP Hydraulic-Profiling results. The results show good agreement between DP data and temperature measurements proving the active heat tracer test is a suitable tool for providing reliable information on aquifer heat-storage capability. References Leaf, A.T., Hart, D.J., Bahr, J.M.: Active Thermal Tracer Tests for Improved Hydrostratigraphic Characterization. Ground Water, vol. 50, 2012 Liu, G., Knobbe, S., Butler, J.J.Jr.: Resolving centimeter-scale flows in aquifers and their hydrostratigraphic controls. Geophysical Research Letters, vol. 40, 2013

  10. Short-Term Storage of Human Spermatozoa in Electrolyte-Free Medium Without Freezing Maintains Sperm Chromatin Integrity Better Than Cryopreservation1

    PubMed Central

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

    2011-01-01

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

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

    Microsoft Academic Search

    Ahmet Sar?; Ali Karaipekli

    2007-01-01

    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

  12. High temperature composite thermal storage systems for industrial applications

    Microsoft Academic Search

    R. J. Petri; E. T. Ong; L. G. Marianowski

    1985-01-01

    The Institute of Gas Technology is developing an advanced, thermal energy storage (TES) subsystem which employs composite phase change\\/material sensible heat media. This medium\\/subsystem is amenable to high temperature thermal storage applications such as industrial reject\\/process heat recovery and use of off-peak utility and solar dynamic space power systems. The concept allows for direct contact heat exchange between the latent\\/sensible

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

    NASA Astrophysics Data System (ADS)

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

    2012-09-01

    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.

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

    Microsoft Academic Search

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

    2008-01-01

    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

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

    Microsoft Academic Search

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

    2004-01-01

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

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

    SciTech Connect

    Buckley, B. S.

    1985-06-25

    A solar collector, or absorber, panels or a heat storage tank, suitable for heating water using solar energy is formed from two sheets of uncured elastic material, such as EPDM rubber, by simultaneously bonding and curing the peripheral edges of the two sheets and at spaced apart, discrete areas over most of the interior areas of the sheets. In one form one of the sheets is coated with a layer of release agent, over all areas except the discrete areas and the peripheral areas so that only such uncoated areas will bond during cure. In another form, a sheet of non-adherent plastic, slightly smaller than the two sheets and having holes or holidays to form the discrete areas, is bonded between the two sheets. In a third form, the peripheral edges are first sealed to form a chamber, then the chamber is inflated and a forming die presses together the discrete areas only. Reinforcing fibers are employed or molded, into at least one of the uncured sheets. Woven fabric sheets may be stitched or fastened together, coated with a thermosetting plastic and then formed into a panel or tank chamber as above. In the solar collector panel embodiment, at least one of the reinforcing fibers is metal, most preferably, in a metal screen to equalize temperatures between the bonded discrete areas and areas overlying liquid carrying volumes of the panel.

  17. Are X-ray Clusters Cooled by Heat Conduction to the Surrounding Intergalactic Medium?

    E-print Network

    Abraham Loeb

    2002-04-29

    We show that X-ray clusters would have cooled substantially over a Hubble time by transport of heat from their hot interior to the their envelope, if the heat conductivity had not been heavily suppressed relative to the Spitzer value due to magnetic fields. The suppression is required in order for the observed abundance of hot X-ray clusters to be consistent with predictions from popular cosmological models. If a similar or stronger suppression factor applies to cluster cores, then thermal conduction can not be the mechanism that prevents cooling flows there.

  18. Programming MOFs for water sorption: amino-functionalized MIL-125 and UiO-66 for heat transformation and heat storage applications.

    PubMed

    Jeremias, Felix; Lozan, Vasile; Henninger, Stefan K; Janiak, Christoph

    2013-12-01

    Sorption-based heat transformation and storage appliances are very promising for utilizing solar heat and waste heat in cooling or heating applications. The economic and ecological efficiency of sorption-based heat transformation depends on the availability of suitable hydrophilic and hydrothermally stable sorption materials. We investigated the feasibility of using the metal-organic frameworks UiO-66(Zr), UiO-67(Zr), H2N-UiO-66(Zr) and H2N-MIL-125(Ti) as sorption materials in heat transformations by means of volumetric water adsorption measurements, determination of the heat of adsorption and a 40-cycle ad/desorption stress test. The amino-modified compounds H2N-UiO-66 and H2N-MIL-125 feature high heat of adsorption (89.5 and 56.0 kJ mol(-1), respectively) and a very promising H2O adsorption isotherm due to their enhanced hydrophilicity. For H2N-MIL-125 the very steep rise of the H2O adsorption isotherm in the 0.1 < p/p0 < 0.2 region is especially beneficial for the intended heat pump application. PMID:23864023

  19. Heat Storage in the Deep Ocean as a Capacitor to Explain Deglaciations.

    NASA Astrophysics Data System (ADS)

    Adkins, J. F.; Thiagarajan, N.

    2014-12-01

    Since the classic work of Hays, Imbrie, and Shackleton in 1976, we have known that glacial cycles are paced by the Milankovitch frequencies. However, it has also been long recognized that deglaciations, especially in the '100k-world', are too abrupt to be a linear response of the climate system to this orbital forcing. To explain this 'sawtooth' behavior, rising pCO2 in the atmosphere has been proposed to be an amplifier of deglacial climate change. Yet this CO2 must come from somewhere and it does not seem to be an early responder in the deglacial sequence of events. Most ideas focus on the deep ocean as the only reservoir large enough to store the CO2 on G-I timescales, including the capacity to release it quickly. Here we propose a new 'capacitor' for the climate system, deep ocean heat storage, that could provide the key physical mechanism to explain the important features of deglacial climate. There is a growing body of evidence, from carbonate stable isotopes and pore water salinity estimates, that the Last Glacial Maximum deep ocean was more stratified than today. Through thermobaricity in seawater's equation of state (the pressure dependence of the thermal expansion coefficient), salt stratification can store heat in a water column that is locally statically stable. However, analogous to CAPE in the atmosphere, this heat energy is convectively available and can lead to large, abrupt deep-ocean mixing. Using clumped isotopes in deep-sea corals from Heinrich Event 1, we have found warmer water underneath colder water, about 800 years before the Bolling-Alerod warming recorded in Greenland ice cores. We propose that the abrupt nature of the Bolling is due to the discharge of this deep ocean thermal capacitor which then changes the deep circulation from a glacial to a modern pattern.

  20. Improvement of a thermal energy storage using plates with paraffin–graphite composite

    Microsoft Academic Search

    José M. Marín; Belén Zalba; Luisa F. Cabeza; Harald Mehling

    2005-01-01

    This work aims at designing a thermal energy storage (TES) using air as heat transfer medium, efficient mainly for free-cooling but also for other applications, improving the low heat transfer rates dues to the thermal conductivity of the materials usually employed in these systems, phase change materials (PCM). In this paper, free-cooling means the storage of cold from the night

  1. Energy storage

    NASA Astrophysics Data System (ADS)

    Kaier, U.

    1981-04-01

    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.

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

    SciTech Connect

    Kingston, T.; Scott, S.

    2013-03-01

    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%.

  3. Energy storage

    Microsoft Academic Search

    U. Kaier

    1981-01-01

    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

  4. Energy Balance Comparison and Closure at a Moist Desert Playa: The Importance of Ground Heat Storage and Flux Estimation

    NASA Astrophysics Data System (ADS)

    Huntington, J. L.; Rajagopal, S.; Allen, R. G.; Mihevc, T. M.; Schumer, R.; Caldwell, T.; deBruin, H.

    2012-12-01

    Given increasing demands on finite water supplies in arid environments, the need for accurate estimates of sustainable groundwater resources is greater than ever. Many drainages in desert environments are considered hydrologically closed, where the entire groundwater recharge volume is consumed by evaporation and evapotranspiration along mountain front and valley floor areas. The amount of groundwater recharge that occurs in a given hydrographic basin is difficult to accurately estimate and is therefore commonly quantified by estimating the groundwater discharge using micrometeorological, and remote and in situ energy balance methods. Large playas are common features in desert environments, and the phreatic surface is often less than a few meters below land surface, creating nearly saturated conditions at the land surface through capillary rise. At first glance one might conclude that evaporation is high due to the nearly saturated surface, however, playa surfaces are commonly sealed by thin salt crusts, inhibiting evaporation. In this work we use eddy covariance, scintillometer, and four component radiometer measurements, and present a novel ground heat flux analysis using multiple ground heat flux plates and heat-pulse sensors to assess energy balance closure and uncertainties on estimated evaporation in Dixie Valley, Nevada. Results indicate that greater than 50 percent of daytime net radiation is partitioned into ground heat flux, and almost all of the available energy is portioned into sensible heat as determined from eddy covariance, and confirmed with scintillometer estimates. Utilizing heat pulse derived soil thermal properties and high density discrete soil temperature measurements allowed for estimation of soil heat storage and flux using a finite difference solution to the transient heat flow equation. This approach improved energy balance closure by 20 percent (achieving 90 percent closure) when compared to traditional calorimetric soil heat storage and flux estimates. We found that underestimation of energy balance closure occurs due to phase lags between 30 minute average available energy and turbulent fluxes, and is primarily due to inaccurate accounting of soil heat storage. Our work highlights the importance of accurate ground heat storage and flux estimation and provides insight into solving the surface energy imbalance problem in complex desert environments.

  5. Technology overview of energy storage systems

    Microsoft Academic Search

    C. M. Buoni; J. Gahimer

    1978-01-01

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

  6. Chlorophylls and carotenoids of kiwifruit puree are affected similarly or less by microwave than by conventional heat processing and storage.

    PubMed

    Benlloch-Tinoco, María; Kaulmann, Anouk; Corte-Real, Joana; Rodrigo, Dolores; Martínez-Navarrete, Nuria; Bohn, Torsten

    2015-11-15

    The impact of microwave (1000W - 340s) and conventional heat (97°C - 30s) pasteurisation and storage (4, 10, 22°C for up to 63d) on total and individual carotenoids and chlorophylls in kiwifruit puree was evaluated. Bioaccessibility of carotenoids, before and after pasteurisation and storage, was also studied. Microwaves and conventional heating led to marked changes in the chlorophyll (42-100% losses) and carotenoid (62-91% losses) content. First- and second-order kinetics appropriately explained the degradation of total carotenoids and chlorophylls over time, respectively. Pasteurised samples showed significantly (p<0.05) enhanced stability of these pigments, with microwaves (k=0.007-0.031100gmg(-1)day(-1) at 4-22°C) promoting chlorophyll stability to a greater extent than conventional heating (k=0.0015-0.034100gmg(-1)day(-1) at 4-22°C). Bioaccessibility of carotenoids remained (p<0.05) unaffected by processing and storage. These results highlighted that the pigment composition of microwaved kiwifruit was more similar to that of the fresh fruit and better preserved during storage. PMID:25977024

  7. Numerical simulation of seasonal heat storage in a contaminated shallow aquifer - Temperature influence on flow, transport and reaction processes

    NASA Astrophysics Data System (ADS)

    Popp, Steffi; Beyer, Christof; Dahmke, Andreas; Bauer, Sebastian

    2015-04-01

    The energy market in Germany currently faces a rapid transition from nuclear power and fossil fuels towards an increased production of energy from renewable resources like wind or solar power. In this context, seasonal heat storage in the shallow subsurface is becoming more and more important, particularly in urban regions with high population densities and thus high energy and heat demand. Besides the effects of increased or decreased groundwater and sediment temperatures on local and large-scale groundwater flow, transport, geochemistry and microbiology, an influence on subsurface contaminations, which may be present in the urban surbsurface, can be expected. Currently, concerns about negative impacts of temperature changes on groundwater quality are the main barrier for the approval of heat storage at or close to contaminated sites. The possible impacts of heat storage on subsurface contamination, however, have not been investigated in detail yet. Therefore, this work investigates the effects of a shallow seasonal heat storage on subsurface groundwater flow, transport and reaction processes in the presence of an organic contamination using numerical scenario simulations. A shallow groundwater aquifer is assumed, which consists of Pleistoscene sandy sediments typical for Northern Germany. The seasonal heat storage in these scenarios is performed through arrays of borehole heat exchangers (BHE), where different setups with 6 and 72 BHE, and temperatures during storage between 2°C and 70°C are analyzed. The developing heat plume in the aquifer interacts with a residual phase of a trichloroethene (TCE) contamination. The plume of dissolved TCE emitted from this source zone is degraded by reductive dechlorination through microbes present in the aquifer, which degrade TCE under anaerobic redox conditions to the degradation products dichloroethene, vinyl chloride and ethene. The temperature dependence of the microbial degradation activity of each degradation step is taken into account for the numerical simulations. Hence, the simulations are performed with the code OpenGeoSys, which is especially suited for simulating coupled thermal, hydraulic and geochemical processes. The scenario simulations show an increase in the source zone emission of TCE at higher temperatures, which is primarily due to the focusing of the groundwater flow in the area of higher temperatures within the source zone and to a lesser part to an increase in TCE solubility. On the other hand, a widening of the contaminant plume and enlargement of the area for TCE biodegradation is induced, which leads to an increase in biodegradation of the chlorinated hydrocarbons. In combination almost no change in the overall ratio of degraded to emitted TCE is found, which shows that the seasonal heat storage is not negatively influencing the present TCE contamination under these assumptions. The results of this work serve to support the risk assessment for the interaction between heat storage and contaminations in the shallow subsurface and show positive interactions as well as possible conflicts.

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

    PubMed

    Kadoono, Tomosuke; Ogura, Masaru

    2014-03-28

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

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

    Microsoft Academic Search

    R. R. Hautala; C. R. Kutal

    1977-01-01

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

  10. Heat transfer in a medium in which many small particles are embedded

    E-print Network

    A. G. Ramm

    2012-07-03

    The heat equation is considered in the complex system consisting of many small bodies (particles) embedded in a given material. On the surfaces of the small bodies a Newton-type boundary condition is imposed. An equation for the limiting field is derived when the characteristic size $a$ of the small bodies tends to zero, their total number $\\mathcal{N}(a)$ tends to infinity at a suitable rate, and the distance $d = d(a)$ between neighboring small bodies tends to zero $a << d$. No periodicity is assumed about the distribution of the small bodies.

  11. Heat and Mass Transfer in a Second Grade Fluid Over a Stretching Vertical Surface in a Porous Medium

    NASA Astrophysics Data System (ADS)

    Baoku, I. G.; Onifade, Y. S.; Adebayo, L. O.; Yusuff, K. M.

    2015-05-01

    The investigation deals with the combined heat and mass transfer in a mixed convection boundary layer flow over a stretching vertical surface in a porous medium filled with a viscoelastic second grade fluid. The partial differential equations governing the model have been transformed by a similarity transformation and the system of coupled-ordinary differential equations is solved by employing the shooting method with the fifth-order Runge-Kutta-Fehlberg iteration technique. Effects of various values of physical parameters embedded in the flow model on the dimensionless velocity, temperature and concentration distributions are discussed and shown with the aid of graphs. Numerical values of physical quantities, such as the local skin-coefficient, local Nusselt number and local Sherwood number are presented in a tabular form. It is observed that the boundary layer fluid velocity increases as the second grade parameter, mixed convection parameter and Prandtl number increase.

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

    PubMed

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

    2014-04-01

    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

  13. A shielded storage and processing facility for radioisotope thermoelectric generator heat source production

    SciTech Connect

    Sherrell, D.L.

    1992-06-01

    This report discusses a shielded storage rack which has been installed as part of the Radioisotope Power Systems Facility (RPSF) at the US Department of Energy's (DOE) Hanford Site in Washington State. The RPSF is designed to replace an existing facility at DOE's Mound Site near Dayton, Ohio, where General Purpose Heat Source (GPHS) modules are currently assembled and installed into Radioisotope Thermoelectric Generators (RTG). The overall design goal of the RPSF is to increase annual production throughput, while at the same time reducing annual radiation exposure to personnel. The shield rack design successfully achieved this goal for the Module Reduction and Monitoring Facility (MRMF), which process and stores assembled GPHS modules, prior to their installation into RTGS. The shield rack design is simple and effective, with the result that background radiation levels within Hanford's MRMF room are calculated at just over three percent of those typically experienced during operation of the existing MRMF at Mound, despite the fact that Hanford's calculations assume five times the GPHS inventory of that assumed for Mound.

  14. A shielded storage and processing facility for radioisotope thermoelectric generator heat source production

    SciTech Connect

    Sherrell, D.L. (Westinghouse Hanford Company, P.O. Box 1970, Mail Stop N1-42, Richland, Washington 99352 (United States))

    1993-01-15

    A shielded storage rack has been installed as part of the Radioisotope Power Systems Facility (RPSF) at the U.S. Department of Energy's (DOE) Hanford Site in Washington State. The RPSF is designed to replace an existing facility at DOE's Mound Site near Dayton, Ohio, where General Purpose Heat Source (GPHS) modules are currently assembled and installed into Radioisotope Thermoelectric Generators (RTG). The overall design goal of the RPSF is to increase annual production throughput, while at the same time reducing annual radiation exposure to personnel. The shield rack design successfully achieved this goal for the Module Reduction and Monitoring Facility (MRMF), which processes and stores assembled GPHS modules, prior to their installation into RTGs. The shield rack design is simple and effective, with the result that background radiation levels within Hanford's MRMF room are calculated at just over three percent of those typically experienced during operation of the existing MRMF at Mound, despite the fact that Hanford's calculations assume five times the GPHS inventory of that assumed for Mound.

  15. A shielded storage and processing facility for radioisotope thermoelectric generator heat source production

    SciTech Connect

    Sherrell, D.L.

    1992-06-01

    This report discusses a shielded storage rack which has been installed as part of the Radioisotope Power Systems Facility (RPSF) at the US Department of Energy`s (DOE) Hanford Site in Washington State. The RPSF is designed to replace an existing facility at DOE`s Mound Site near Dayton, Ohio, where General Purpose Heat Source (GPHS) modules are currently assembled and installed into Radioisotope Thermoelectric Generators (RTG). The overall design goal of the RPSF is to increase annual production throughput, while at the same time reducing annual radiation exposure to personnel. The shield rack design successfully achieved this goal for the Module Reduction and Monitoring Facility (MRMF), which process and stores assembled GPHS modules, prior to their installation into RTGS. The shield rack design is simple and effective, with the result that background radiation levels within Hanford`s MRMF room are calculated at just over three percent of those typically experienced during operation of the existing MRMF at Mound, despite the fact that Hanford`s calculations assume five times the GPHS inventory of that assumed for Mound.

  16. Heating and Ionization of the Intergalactic Medium by an Early X-Ray Background

    E-print Network

    Aparna Venkatesan; Mark L. Giroux; J. Michael Shull

    2001-08-09

    Observational studies indicate that the intergalactic medium (IGM) is highly ionized up to redshifts just over 6. A number of models have been developed to describe the process of reionization and the effects of the ionizing photons from the first luminous objects. In this paper, we study the impact of an X-ray background, such as high-energy photons from early quasars, on the temperature and ionization of the IGM prior to reionization, before the fully ionized bubbles associated with individual sources have overlapped. X-rays, which have large mean free paths relative to EUV photons, and their photoelectrons can have significant effects on the thermal and ionization balance. We find that hydrogen ionization is dominated by the X-ray photoionization of neutral helium and the resulting secondary electrons. Thus, the IGM may have been warm and weakly ionized prior to full reionization. We examine several related consequences, including the filtering of the baryonic Jeans mass scale, signatures in the cosmic microwave background, and the H$^{-}$-catalyzed production of molecular hydrogen.

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

    Microsoft Academic Search

    R. R. Hautala; C. R. Kutal

    1977-01-01

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

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

    PubMed

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

    2014-12-01

    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

  19. Thermal Properties and Thermal Reliability of Capric Acid\\/Stearic Acid Mixture for Latent Heat Thermal Energy Storage

    Microsoft Academic Search

    A. Kara?pekl?; A. Sar?; K. Kaygusuz

    2009-01-01

    This study focuses on the preparation of capric acid\\/stearic acid mixture as novel phase change material for latent heat thermal energy storage and determination of its thermal properties and thermal reliability by using differential scanning calorimetry analysis technique. The differential scanning calorimetry results indicated that the capric acid\\/stearic acid mixture with eutectic composition (83\\/17 wt%) was suitable phase change material

  20. The capric and lauric acid mixture with chemical additives as latent heat storage materials for cooling application

    Microsoft Academic Search

    M. N Roxas-Dimaano; T Watanabe

    2002-01-01

    The mixture of capric acid and lauric acid (C-L acid), with the respective mole composition of 65% and 35%, is a potential phase change material (PCM). Its melting point of 18.0°C, however, is considered high for cooling application of thermal energy storage. The thermophysical and heat transfer characteristics of the C-L acid with some organic additives are investigated. Compatibility of

  1. Compositional, functional and storage properties of flours from raw and heat processed African breadfruit ( Treculia africana Decne) seeds

    Microsoft Academic Search

    Sunday Y. Giami; Matthew N. Adindu; Monday O. Akusu; Juliet N. T. Emelike

    2000-01-01

    African breadfruit (Treculia africana Decne) seeds were either boiled or roasted and then milled into flour. Chemical composition, functional properties and storage characteristics of raw and treated flours and the effect of partial proteolysis on selected functional properties of the raw flour were determined. Raw flour contained 20.1% crude protein, 2.5% total ash and 13.7% fat. Heat processing significantly (pp<0.05)

  2. Some fatty acids used for latent heat storage: thermal stability and corrosion of metals with respect to thermal cycling

    Microsoft Academic Search

    A Sar?; K Kaygusuz

    2003-01-01

    The present study includes thermal stability of some fatty acids as phase change materials (PCMs). The selected fatty acids were stearic, palmitic, myristic and lauric acid with melting temperatures between 40–63°C and industrial-grade with 90–95 % purity. Latent heat storage capacity and phase transition temperature of the PCMs were determined by Differential Scanning Calorimetry (DSC) technique as a function of

  3. White tea as a promising antioxidant medium additive for sperm storage at room temperature: a comparative study with green tea.

    PubMed

    Dias, Tânia R; Alves, Marco G; Tomás, Gonçalo D; Socorro, Sílvia; Silva, Branca M; Oliveira, Pedro F

    2014-01-22

    Storage of sperm under refrigeration reduces its viability, due to oxidative unbalance. Unfermented teas present high levels of catechin derivatives, known to reduce oxidative stress. This study investigated the effect of white tea (WTEA) on epididymal spermatozoa survival at room temperature (RT), using green tea (GTEA) for comparative purposes. The chemical profiles of WTEA and GTEA aqueous extracts were evaluated by (1)H NMR. (-)-Epigallocatechin-3-gallate was the most abundant catechin, being twice as abundant in WTEA extract. The antioxidant power of storage media was evaluated. Spermatozoa antioxidant potential, lipid peroxidation, and viability were assessed. The media antioxidant potential increased the most with WTEA supplementation, which was concomitant with the highest increase in sperm antioxidant potential and lipid peroxidation decrease. WTEA supplementation restored spermatozoa viability to values similar to those obtained at collection time. These findings provide evidence that WTEA extract is an excellent media additive for RT sperm storage, to facilitate transport and avoid the deleterious effects of refrigeration. PMID:24372402

  4. Invariant solutions of the heat-conduction equation describing the directed propagation of combustion and spiral waves in a nonlinear medium

    NASA Astrophysics Data System (ADS)

    Bakirova, M. I.; Dorodnitsyn, V. A.; Kurdiumov, S. P.; Samarskii, A. A.; Dimova, S. N.

    The directed propagation of heat and combustion in an anisotropic medium is analyzed numerically. It is shown that at the asymptotic stage this process is described by an invariant (self-similar) solution obtained by Dorodnitsyn et al. (1983). In the isotropic case, an invariant solution is indicated which can describe circular and spiral combustion waves. The invariant solutions are obtained on the basis of the group properties of the heat-conduction equation.

  5. THERMAL ENERGY STORAGE OPPORTUNITIES FOR RESIDENTIAL SPACE COOLING: A TECHNOLOGY TO MANAGE DEMAND RESPONSE AND REDUCE CUSTOMER COSTS

    Microsoft Academic Search

    C. Alvarez; A. Gabaldon; E. Gómez; A. Molina

    Cool thermal energy storage could become one of the primary solutions to manage peaks, low load factors, electrical power imbalance between daytime and nighttime, and to offer the possibility to reduce electricity costs for the customer. This kind of storage uses off-peak power to provide cooling capacity by extracting heat from a storage medium. Typically these systems use refrigeration equipment

  6. A numerical study of convection in a layered porous medium heated from below

    SciTech Connect

    Hickox, C.E.; Chu, Tze Yao.

    1990-01-01

    As part of the Magma Energy Project being pursued at Sandia National Laboratories, a drilling program has been initiated within the Long Valley caldera near Mammoth Lakes, California. Seismological evidence obtained in this region suggests the presence of a relatively shallow magma body. We have performed a numerical simulation for a simplified model of the Long Valley geothermal system in order to elucidate the nature of the large-scale thermal structure within the system and to assess implications for the drilling program. The two-dimensional model consists of three horizontal layers, the upper two of which are porous and saturated with a single phase fluid. The system is limited in horizontal extent and heated uniformly from below. An associated planar, natural convective flow is thus produced. The results of our simulation indicate the possibility of wide variations in vertical temperature profiles for the model system, depending on the location of the drilling operation. Thus it can be inferred that, during the early stages of drilling, the vertical temperature distribution is not a reliable indicator of the presence or absence of a magma body at depth. 14 refs., 5 figs., 4 tabs.

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

    PubMed

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

    2014-02-28

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

  8. Heat transfer performance of a phase-change thermal energy storage water heater using cross-linked high density polyethylene pellets

    SciTech Connect

    Jotshi, C.K.; Klausner, J.F.; Goswami, D.Y.; Hsieh, C.K. [Univ. of Florida, Gainesville, FL (United States); Santhosh, M.K. [Hanson Technical Corp., Burridge, IL (United States); Colacino, F. [Florida Power and Light Co., Miami, FL (United States)

    1996-12-31

    The objective of this investigation was to develop an efficient water heater that stores thermal energy in a mixture of cross-linked high density polyethylene (HDPE) pellets and propylene glycol. Properties of cross-linked HDPE, such as melting and crystallization temperatures, heat of fusion and crystallization, and volume change were measured in the laboratory. The heat transfer coefficient for the mixture was also measured in a laboratory test. A prototype model of a storage water heater using a mixture of cross-linked HDPE pellets and propylene glycol was designed and fabricated. A copper finned heat transfer coil was used to extract the heat from the storage tank by passing water through it. The heat transfer efficiency (heat extracted by water/heat stored) was measured to be about 70%. To increase the efficiency, the storage unit was modified. In the modified unit, the length of the heat transfer coil was increased and coil spacing optimized. With the modification, the heat transfer efficiency was measured to be about 90%. In addition, a variable heat flux heating element, having high heat flux at the bottom and low heat flux at top, was used to reduce thermal stratification of the propylene glycol/HDPE pellet mixture.

  9. Advanced high-temperature molten-salt storage research

    SciTech Connect

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

    1983-08-01

    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.

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

    SciTech Connect

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

    2014-11-03

    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

  11. Second law analysis of a diesel engine waste heat recovery with a combined sensible and latent heat storage system

    Microsoft Academic Search

    V. Pandiyarajan; M. Chinnappandian; V. Raghavan; R. Velraj

    2011-01-01

    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. The major technical constraint that prevents successful implementation of waste heat recovery is due to intermittent and time mismatched demand for and availability of energy. The present work

  12. High-temperature composite thermal energy storage for industrial applications

    Microsoft Academic Search

    R. J. Petri; E. T. Ong; L. G. Marianowski

    1985-01-01

    An advanced, thermal energy storage (TES) subsystem is being developed by the Institute of Gas Technology (IGT) which employs composite phase change material (PCM)\\/sensible heat media (CompPhase). This medium\\/subsystem is amenable to high temperature thermal storage applications such as industrial reject\\/process heat recovery and utilization, off-peak utility, and solar thermal and solar dynamic space power systems. The CompPhase concept allows

  13. High temperature composite thermal storage systems for industrial applications

    Microsoft Academic Search

    R. J. Petri; E. R. Ong; L. G. Marianowski

    1985-01-01

    An advanced, thermal energy storage (TES) subsystem is being developed by the Institute of Gas Technology (IGT which employs composite phase change material (PCM)\\/sensible heat media (CompPhase). This medium\\/subsystem is amenable to high temperature thermal storage applications such as industrial reject\\/process heat recovery and utilization, off-peak utility, and solar thermal and solar dynamic space power systems. The CompPhase concept allows

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

    NASA Astrophysics Data System (ADS)

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

    1980-11-01

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

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

    Microsoft Academic Search

    M. K. Choi; J. H. Morehouse; P. J. Hughes

    1980-01-01

    This study performed an analysis of ground-coupled stand-alone and series configured solar-assisted liquid-to-air heat pump systems for residences. The year-round thermal performance of these systems for space heating, space cooling, and water heating were determined by simulation and compared against non-ground-coupled solar heat pump systems as well as conventional heating and cooling systems in three geographic locations: Washington, D.C., Fort

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

    Microsoft Academic Search

    Cemil Alkan; Ahmet Sari

    2008-01-01

    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

  17. Quasi-steady state temperature distribution and numerical simulation on low Ste number latent heat storage thermal unit of solar thermal power generation

    Microsoft Academic Search

    J. Huang; D. S. Zhu

    2010-01-01

    Solar thermal power generation systems, including direct steam generation, require isothermal energy storage systems for a saturation temperature range between 190° C and 310° C. One option to fulfill this requirement is the application of phase-change materials to absorb or release energy. In this paper, the basic concept of latent heat storage system is described, and a model of phase-change

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

    SciTech Connect

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

    2014-01-01

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

  19. Microwave Heating Inactivates Shiga Toxin (Stx2) in Reconstituted Fat-Free Milk and Adversely Affects the Nutritional Value of Cell Culture Medium.

    PubMed

    Rasooly, Reuven; Hernlem, Bradley; He, Xiaohua; Friedman, Mendel

    2014-03-26

    Microwave exposure is a convenient and widely used method for defrosting, heating, and cooking numerous foods. Microwave cooking is also reported to kill pathogenic microorganisms that often contaminate food. In this study, we tested whether microwaves would inactivate the toxicity of Shiga toxin 2 (Stx2) added to 5% reconstituted fat-free milk administered to monkey kidney Vero cells. Heating of milk spiked with Stx2 in a microwave oven using a 10% duty cycle (cycle period of 30 s) for a total of 165 kJ energy or thermal heating (pasteurization), widely used to kill pathogenic bacteria, did not destroy the biological effect of the toxin in the Vero cells. However, conventional heating of milk to 95 °C for 5 min or at an increased microwave energy of 198 kJ reduced the Stx2 activity. Gel electrophoresis showed that exposure of the protein toxin to high-energy microwaves resulted in the degradation of its original structure. In addition, two independent assays showed that exposure of the cell culture medium to microwave energy of 198 kJ completely destroyed the nutritional value of the culture medium used to grow the Vero cells, possibly by damaging susceptible essential nutrients present in the medium. These observations suggest that microwave heating has the potential to destroy the Shiga toxin in liquid food. PMID:24669932

  20. Investigation of Transient, Turbulent Natural Convection in Vertical Tubes for Thermal Energy Storage in Supercritical CO2

    NASA Astrophysics Data System (ADS)

    Baghaei Lakeh, Reza; Lavine, Adrienne S.; Kavehpour, H. Pirouz; Wirz, Richard E.

    2013-11-01

    Heat transfer can be a limiting factor in the operation of thermal energy storage, including sensible heat and latent heat storage systems. Poor heat transfer between the energy storage medium and the container walls impairs the functionality of the thermal storage unit by requiring excessively long times to charge or discharge the system. In this study, the effect of turbulent, unsteady buoyancy-driven flow on heat transfer in vertical storage tubes containing supercritical CO2 as the storage medium is investigated computationally. The heat transfer from a constant-temperature wall to the storage fluid is studied during the charge cycle. The results of this study show that turbulent natural convection dominates the heat transfer mechanism and significantly reduces the required time for charging compared to pure conduction. Changing the L/D ratio of the storage tube has a major impact on the charge time. The charge time shows a decreasing trend with RaL. The non-dimensional model of the problem shows that Nusselt number and non-dimensional mean temperature of the storage fluid in different configurations of the tube is a function Buoyancy-Fourier number defined as of FoL * RaLm* L/D. Heat transfer can be a limiting factor in the operation of thermal energy storage, including sensible heat and latent heat storage systems. Poor heat transfer between the energy storage medium and the container walls impairs the functionality of the thermal storage unit by requiring excessively long times to charge or discharge the system. In this study, the effect of turbulent, unsteady buoyancy-driven flow on heat transfer in vertical storage tubes containing supercritical CO2 as the storage medium is investigated computationally. The heat transfer from a constant-temperature wall to the storage fluid is studied during the charge cycle. The results of this study show that turbulent natural convection dominates the heat transfer mechanism and significantly reduces the required time for charging compared to pure conduction. Changing the L/D ratio of the storage tube has a major impact on the charge time. The charge time shows a decreasing trend with RaL. The non-dimensional model of the problem shows that Nusselt number and non-dimensional mean temperature of the storage fluid in different configurations of the tube is a function Buoyancy-Fourier number defined as of FoL * RaLm* L/D. This study was supported by award No. DE-AR0000140 granted by U.S. Department of Energy under Advanced Research Projects Agency - Energy (ARPA-E) and by award No. 5660021607 granted by Southern California Gas Company.

  1. Thermal energy storage and heat transfer support program. Task5 heat pipe life test study. Facilities upgrading and maintenance

    Microsoft Academic Search

    R. Ponnappan

    1991-01-01

    This report describes the recommissioning, upgrading, and maintaining of thirty low and five high temperature heat pipe life test rigs. This is an ongoing research effort, originally put together by NASA LeRC, continued by the Air Force. The 92 cm long 1.27 cm dia. spacecraft-type heat pipes have completed nearly 74,000 hours of life tests. They exhibit varying Delta Ts

  2. A Study on a Perfaormance of Water-Spray-Type Ice Thermal Energy Storage Vessel with Vertical Heat Exchange Plates

    NASA Astrophysics Data System (ADS)

    Yoshimura, Kenji; Koyama, Shigeru; Fukuda, Toshihito; Ohba, Hideki

    A system with a water -embedded-type ice storage vessel is widely used because of its simple structure compactness. However, this ice storage vessel has a disadvantage, that is, the melting rate is very small. The use of falling water film seems to be one of promising ways for solving this disadvantage. We have found in our previous study that the use of the falling water film is very effective, especially for high initial water temperatures. In the present study, we examined the melting performance of a falling-water-film-type ice thermal energy storage vessel with practical size, having vertical heat exchange plates. The results obtained are as follows : the quantity of melting ice increases with increase of the water film flow rate, the melting rate decreases with time because ice surface are decreases with time gradually, the heat transfer coefficient of melting increases with increase of the water film flow rate, and the melting rate increases with increase of the water-spray temperature.

  3. Combined heat and power plant integrated with mobilized thermal energy storage (M-TES) system

    Microsoft Academic Search

    Weilong Wang; Yukun Hu; Jinyue Yan; Jenny Nyström; Erik Dahlquist

    2010-01-01

    Energy consumption for space and tap water heating in residential and service sectors accounts for one third of the total\\u000a energy utilization in Sweden. District heating (DH) is used to supply heat to areas with high energy demand. However, there\\u000a are still detached houses and sparse areas that are not connected to a DH network. In such areas, electrical heating

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

    NASA Technical Reports Server (NTRS)

    Saha, H.

    1978-01-01

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

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

    PubMed Central

    Tanaka, Kenkou; Cho, Yasuo

    2010-01-01

    A new method to achieve real information recording with a density above 1 Tbit?in.2 in ferroelectric data storage systems is proposed. In this system, data bits were written in the form of the polarization direction, and the data were read by scanning nonlinear dielectric microscopy technique. The domain-switching characteristics of the virgin and inversely prepolarized media were compared, and the conditions of the pulse voltage for writing were optimized. As a result, actual data containing 64×64 bits were recorded at an areal density of 4 Tbit?in.2. The bit error rate was evaluated to be 1.2×10?2. PMID:20877653

  6. On the heat removal characteristics and the analytical model of a thermal energy storage capsule using gelled Glauber's salt as the PCM

    Microsoft Academic Search

    Akio Saito; Seiji Okawa; Tadafumi Shintani; Ryuichiro Iwamoto

    2001-01-01

    An analytical and experimental investigation was performed on a heat removal process of the thermal energy storage (TES) capsule, using gelled Glauber's salt. Transient heat flux at the capsule wall was measured for various cooling conditions. In cases where the initial temperature was lower than the saturation temperature of the phase change material (PCM), numerical analyses were performed, approximating the

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

    NASA Astrophysics Data System (ADS)

    Zhang, Jingjing; Huang, Tao; Yu, Aishui

    2015-01-01

    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.

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

    E-print Network

    Wood, Stanley Clayton

    1982-01-01

    Mortar, Low Flow/ Low Temperature Figure 3. 5 Cement Mortar, Low Flow/Medium Temperature 35 Figure 3. 6 Cement Mortar, Low Flow/High Temperature Figure 3. 7 Cement Mortar, High Flow/Low Temperature Figure 3. 8 Cement Mortar, High Flow.../Medium Temperature 3S LIST OF FIGURES (Cont'd) PAGE Figure 3. 9 Cement Mortar, High Flow/High Figure T emperature 39 3. 10 Rocks Low Flow/Low Temperature --------- 40 Figure 3. 11 Rocks, Low Flow/Medium Temperature ------ 41 Figure 3. 12 Rocks, Low Flow...

  9. Quasi-steady state temperature distribution and numerical simulation on low Ste number latent heat storage thermal unit of solar thermal power generation

    NASA Astrophysics Data System (ADS)

    Huang, J.; Zhu, D. S.

    2010-03-01

    Solar thermal power generation systems, including direct steam generation, require isothermal energy storage systems for a saturation temperature range between 190° C and 310° C. One option to fulfill this requirement is the application of phase-change materials to absorb or release energy. In this paper, the basic concept of latent heat storage system is described, and a model of phase-change heat transfer of latent heat storage thermal unit for thermal energy storage system is built. Base on the practical thermo-physical properties of phase-change materials, Quasi-Steady State temperature distribution of phase-change heat transfer is analyzed under low Ste number. Numerical simulation (finite element method) taking account into the sensible heat is adopted and the results prove that the Quasi-Steady State temperature distribution obtained from theoretical is in good agreement with the results of numerical simulation. For a latent heat storage system with low Ste number characteristic, Quasi-Steady State solution can be used as the theoretical calculation foundation for engineering design.

  10. 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

    Anica Trp

    2005-01-01

    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),

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

    SciTech Connect

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

    2011-10-15

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

  12. Low-cost phase change material as an energy storage medium in building envelopes: Experimental and numerical analyses

    SciTech Connect

    Biswas, Kaushik [ORNL; Abhari, Mr. Ramin [Renewable Energy Group, Inc.

    2014-01-01

    A promising approach to increasing the energy efficiency of buildings is the implementation of a phase change material (PCM) in the building envelope. Numerous studies over the last two decades have reported the energy saving potential of PCMs in building envelopes, but their wide application has been inhibited, in part, by their high cost. This article describes a novel PCM made of naturally occurring fatty acids/glycerides trapped into high density polyethylene (HDPE) pellets and its performance in a building envelope application. The PCM-HDPE pellets were mixed with cellulose insulation and then added to an exterior wall of a test building in a hot and humid climate, and tested over a period of several months, To demonstrate the efficacy of the PCM-enhanced cellulose insulation in reducing the building envelope heat gains and losses, side-by-side comparison was performed with another wall section filled with cellulose-only insulation. Further, numerical modeling of the test wall was performed to determine the actual impact of the PCM-HDPE pellets on wall-generated heating and cooling loads and the associated electricity consumption. The model was first validated using experimental data and then used for annual simulations using typical meteorological year (TMY3) weather data. This article presents the experimental data and numerical analyses showing the energy-saving potential of the new PCM.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    1985-12-01

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

  15. Experimental study and evaluation of latent heat storage in phase change materials wallboards

    Microsoft Academic Search

    Lv Shilei; Feng Guohui; Zhu Neng; Dongyan Li

    2007-01-01

    Phase change materials (PCM) can be applied in building envelops to conserve heat energy. Wallboards incorporated with PCM can automatically absorb indoor redundant heat, which can greatly reduce the load of HVAC systems and save electric energy. In experiments, a PCM wallboard room was constructed by attaching PCM wallboards, developed by incorporating about 26% PCM by weight into gypsum wallboards,

  16. Optimization of hybrid – ground coupled and air source – heat pump systems in combination with thermal storage

    Microsoft Academic Search

    N. Pardo; Á. Montero; J. Martos; J. F. Urchueguía

    2010-01-01

    Ground coupled heat pumps are attractive solutions for cooling and heating commercial buildings due to their high efficiency and their reduced environmental impact. Two possible ideas to improve the efficiency of these systems are decoupling energy generation from energy distribution and combining different HVAC systems. Based on these two ideas, we present several HVAC configurations which combine the following equipments:

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

    SciTech Connect

    NONE

    1997-06-01

    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.

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

    Microsoft Academic Search

    G. Kocar; A. Eryasar

    2007-01-01

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

  19. In situ immunohistochemical study of Bcl-2 and heat shock proteins in human corneal endothelial cells during corneal storage

    PubMed Central

    Gain, P.; Thuret, G.; Chiquet, C.; Dumollard, J. M.; Mosnier, J. F.; Campos, L.

    2001-01-01

    AIM—To investigate the expression of Bcl-2 and heat shock proteins (HSPs), which are known to increase cell survival, in human corneal endothelial cells (HCECs) of corneas stored in organ culture.?METHODS—32 paired corneas were randomly assigned to either a short or a long storage time. The flat mounts of endothelium were examined after immunostaining with monoclonal antibodies to Bcl-2 and HSP 27, 60, 70, and 90.?RESULTS—HCECs expressed generally all the proteins studied. Bcl-2 expression was weaker in the long stored corneas (p=0.035). There was no relation between immunostaining, age, sex, or death to culture time. Frequently some Descemet membranes carried negative cells preferentially located in folds and exhibiting morphological changes consistent with swelling cells corresponding to early stages of apoptosis.?CONCLUSION—Expression of these cytoprotective proteins reflects the high level of HCEC resistance to stresses induced by organ culture. The decreased immunostaining of Bcl-2 in the long storage group could act in cellular loss currently observed with storage time. The negativity of Bcl-2 and HSP labelling in corneal folding may be related to apoptosis.?? PMID:11466261

  20. SERI solar energy storage program

    Microsoft Academic Search

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

    1982-01-01

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

  1. Finite element analysis of phase-change storage media

    SciTech Connect

    Jabbar, M.; Najafi, M. [Univ. of Southwestern Louisiana, Lafayette, LA (United States). Mechanical Engineering Dept.

    1995-12-31

    The objective of this study is to predict the cooling curve for the storage tank of a clathrate (crystalline compounds made of gaseous refrigerant and water) thermal energy storage system using finite element analysis. The analysis involve modeling of a storage medium which changes its phase from liquid to solid within the storage tank. The solidification of the storage medium takes place during the storage tank`s heat extraction simulation process (charging process). The storage media in this study are Refrigerant 134a (R134a) clathrate and Refrigerant 12 (R12) clathrate. The enthalpy based standard approach is utilized to overcome the phase change discontinuities. The governing equations count for the phase change, two dimensional conduction, and convection modes. The cooling of the storage medium is simulated as energy loss from the storage tank contents. A set of algebraic discretized equations are obtained from the governing equations through the method of finite element formulation. These algebraic equations are solved using the common purpose computational fluid dynamics analysis package (FIDAP, 1991) to obtain the temperature distribution and consequently the cooling curve for the storage tank. The results for R12 clathrate are in good agreement with the experimental results obtained by Najafi and Schaetzle (1991). For R134a clathrate the results obtained follow a pattern similar to those of experimental work on R12 clathrate. The work of this study provides the necessary background for conducting experimental studies on R134a clathrate thermal energy storage system.

  2. Advanced thermal energy storage concept definition study for solar Brayton power plants. Volume II. Thermal energy storage system sizing computer program, July 1December 31, 1976. [Thermal energy storage sizing model

    Microsoft Academic Search

    Gintz

    1976-01-01

    This document describes the computer program used in conceptual studies of phase change and sensible heat thermal energy storage systems. The model assumes the phase change media is contained in a tube-in-bath configuration. The sensible heat medium is contained in high pressure tanks. The program has been used in conjunction with, but is not necessarily limited to, a high temperature,

  3. Migration of bisphenol A from can coatings—effects of damage, storage conditions and heating

    Microsoft Academic Search

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

    2004-01-01

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

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

    Microsoft Academic Search

    D. K. Benson; C. Christensen

    1983-01-01

    A set of solid state phase change materials was evaluated for possible use in passive solar thermal energy storage systems. The most promising materials are organic solid solutions of pentaerythritol, pentaglycerine and neopentyl glycol. Solid solution mixtures of these compounds can be tailored so that they exhibit solid-to-solid phase transformations at any desired temperature within the range from less than

  5. Optical data storage and metallization of polymers

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Kuznetsova, Svetlana A.

    2015-01-01

    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.

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

    E-print Network

    Paris-Sud XI, Université de

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

  8. Thermal-fluid flow within innovative heat storage concrete systems for solar power plants

    Microsoft Academic Search

    Valentina A. Salomoni; Carmelo E. Majorana; Giuseppe M. Giannuzzi; Adio Miliozzi

    2008-01-01

    Purpose – The purpose of this paper is to describe an experience of R&D in the field of new technologies for solar energy exploitation within the Italian context. Concentrated solar power systems operating in the field of medium temperatures are the main research objectives, directed towards the development of a new and low-cost technology to concentrate the direct radiation and

  9. Plant for supplying heating systems with solid flowable fuel

    Microsoft Academic Search

    Link

    1984-01-01

    An apparatus for supplying stationary small- to medium-sized heating plant with flowable solid fuel such as coal dust or coal breeze has a vacuum conveyor running from a fuel storage container of the apparatus to the heating plant for transporting the fuel from the container to the boiler. The blower of the conveyor has an aspiration port joined up with

  10. The absorption process for heating, cooling and energy storage - An historical survey

    NASA Astrophysics Data System (ADS)

    Bjurstrom, H.; Raldow, W.

    1981-03-01

    A historical overview of the absorption process is given and a wide range of applications, from household refrigerators and air conditioners to topping processes in power plants, are surveyed in historical perspective. The production of mechanical energy and open systems are also included. The current development of the absorption process is sketched out and special attention is given to the aspects of thermal energy storage.

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

    Microsoft Academic Search

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

    1982-01-01

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

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

    DOEpatents

    Soroushian, Parviz (Lansing, MI)

    2002-01-01

    A thermoplastic polymer of relatively low melt temperature is blended with at least one of thermosets, elastomers, and thermoplastics of relatively high melt temperature in order to produce a polymer blend which absorbs relatively high quantities of latent heat without melting or major loss of physical and mechanical characteristics as temperature is raised above the melting temperature of the low-melt-temperature thermoplastic. The polymer blend can be modified by the addition of at least one of fillers, fibers, fire retardants, compatibilisers, colorants, and processing aids. The polymer blend may be used in applications where advantage can be taken of the absorption of excess heat by a component which remains solid and retains major fractions of its physical and mechanical characteristics while absorbing relatively high quantities of latent heat.

  13. Studies on heat capacities and thermal analysis of Li–Mg–N–H hydrogen storage system

    Microsoft Academic Search

    F. Xu; L. X. Sun; P. Chen; Y. N. Qi; J. Zhang; J. N. Zhao; Y. F. Liu; L. Zhang; Zhong Cao; D. W. Yang; J. L. Zeng; Y. Du

    2010-01-01

    The heat capacities of LiNH2 and Li2MgN2H2 were measured by a modulated differential scanning calorimetry (MDSC) over the temperature range from 223 to 473 K for the\\u000a first time. The value of heat capacity of LiNH2 is bigger than that of Li2MgN2H2 from 223 to 473 K. The thermodynamic parameters such as enthalpy (H–H\\u000a 298.15) and entropy (S–S\\u000a 298.15) versus 298.15 K were

  14. Evaluation of swine fertilisation medium (SFM) efficiency in preserving spermatozoa quality during long-term storage in comparison to four commercial swine extenders.

    PubMed

    Fantinati, P; Zannoni, A; Bernardini, C; Forni, M; Tattini, A; Seren, E; Bacci, M L

    2009-02-01

    In pig production, artificial insemination is widely carried out and the use of fresh diluted semen is predominant. For this reason, there are increasing interests in developing new extenders and in establishing the optimal storage conditions for diluted spermatozoa. In the last few decades, we utilised a homemade diluent (swine fertilisation medium (SFM)) for spermatozoa manipulation and biotechnological application as the production of transgenic pigs utilising the sperm-mediated gene transfer technique. The purpose of the present study is therefore to analyse the ability of SFM, in comparison to four commercial extenders, in preserving the quality of diluted boar semen stored at 16.5°C till 15 days. We utilised some of the main predictive tests as objectively measured motility, acrosome and sperm membrane integrity, high mitochondrial membrane potential and pH. Based on our in vitro study, SFM could be declared as a good long-term extender, able to preserve spermatozoa quality as well as Androhep Enduraguard for up to 6 to 9 days and more. PMID:22444230

  15. Analysis of the influence of operating conditions and geometric parameters on heat transfer in water-paraffin shell-and-tube latent thermal energy storage unit

    Microsoft Academic Search

    Anica Trp; Kristian Lenic; Bernard Frankovic

    2006-01-01

    A transient heat transfer phenomenon during charging and discharging of the shell-and-tube latent thermal energy storage system has been analysed in this paper. The mathematical model, regarding the conjugate problem of transient forced convection and solid–liquid phase change heat transfer based on the enthalpy formulation, has been presented. A fully implicit two-dimensional control volume FORTRAN computer code has been developed

  16. The solar heating system with seasonal storage at the Solar-Campus Jülich

    Microsoft Academic Search

    Michael Meliß; Frank Späte

    2000-01-01

    The Solar-Campus Jülich is an area of 14 ha in the north of the existing University of Applied Sciences. Three independent partners are constructing low energy buildings on this site (heating demand ?144 MJ m?2 a?1). To date (June 2000) an auditorium with a library has been completed as well as an additional laboratory building. The Students’ Association Aachen has

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

    SciTech Connect

    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

    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.

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

    PubMed Central

    2013-01-01

    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

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

    PubMed

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

    2013-01-01

    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

  20. Field demonstration of the Thermostone III trademark electric thermal storage furnace

    SciTech Connect

    Ferraro, V.D.; Gibson, G.L.; Ishii, R.K. (Science Applications International Corp., San Diego, CA (United States))

    1992-04-01

    Electric thermal storage (ETS) furnaces use off-peak electricity to store heat for on-peak periods. During the 1988--1989 and 1989--1990 heating seasons, the Electric Power Research Institute (EPRI) sponsored a field demonstration of a commercial heat storage furnace which uses common crushed rock (basalt) as the storage medium. The furnaces were manufactured by the CaliDyne Corporation, Minneapolis, Minnesota, under the brand name Thermostone III{trademark}. The purpose of the field demonstration was to determine the Thermostone III's performance by evaluating its energy consumption, load shape characteristics, heating comfort, and reliability. A previous EPRI field test of 15 prototype heat storage furnaces verified that crushed rock ETS furnaces can maintain comfort, even under severe winter conditions, while shifting all electricity for heating to off-peak hours.

  1. 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...

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

    Microsoft Academic Search

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

    2002-01-01

    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

  3. High-Temperature Short-Time Sterilized Evaporated Milk. III. The Influence of the Lipid Phase on Heat and Storage Stability

    Microsoft Academic Search

    Abraham Leviton; Michael J. Pallansch

    1961-01-01

    SUMMARY Laboratory experiments in which high temperature-short time sterilization of con- centrated milk was carried out under static conditions showed that heat and storage stability were at times adversely affected by the presence of a lipid phase. Three types of milk were encountered. The predominant type (if forewarming was employed) con- sisted of milks in which the fat phase behaved

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    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.

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

    Microsoft Academic Search

    J. L. Xu; Y. H. Gan

    2007-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

    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.

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

    Microsoft Academic Search

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

    2010-01-01

    On separate days, eight physically active younger (22 ± 2 years) and eight highly trained middle-aged (45 ± 4 years) men matched\\u000a for physical fitness and body composition performed 90 min of semi-recumbent cycling at a constant rate of heat production\\u000a (290 W) followed by 60 min of seated recovery in either a temperate (T, 30°C), warm (W, 35°C) or hot (H, 40°C) ambient condition. Rectal temperature (T\\u000a re)

  10. 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

    Molva, Celenk; Baysal, Ayse Handan

    2014-10-17

    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

  11. Advanced thermal energy storage concept definition study for solar Brayton power plants. Volume II. Thermal energy storage system sizing computer program. Period covered: July 1, 1976December 31, 1976

    Microsoft Academic Search

    Gintz

    1977-01-01

    This document describes the computer program used in conceptual studies of phase change and sensible heat thermal energy storage systems. The model assumes the phase change media is contained in a tube-in-bath configuration. The sensible heat medium is contained in high pressure tanks. The program has been used in conjunction with, but is not necessarily limited to, a high temperature,

  12. Solar heating and cooling of mobile homes test results

    Microsoft Academic Search

    A. S. Jacobsen

    1977-01-01

    An integrated solar heated and cooled mobile home has been developed by a combined ERDA\\/GE project. The basic sub-systems include: a solar collector array, an energy storage medium, and heating\\/cooling equipment. The system may be controlled either manually or automatically from a console located in a bedroom. The system operates in a variety of modes including one for excess heat

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

    PubMed

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

    2013-10-01

    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

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

    SciTech Connect

    Marseille, T.J.; Johnson, B.K.; Wallin, R.P.; Chiu, S.A.; Crawley, D.B.

    1989-01-01

    This report is one in a series of reports describing research activities in support of the US Department of Energy (DOE) Commercial Building System Integration Research Program. The goal of the program is to develop the scientific and technical basis for improving integrated decision-making during design and construction. Improved decision-making could significantly reduce buildings' energy use by the year 2010. The objectives of the Commercial Building System Integration Research Program are: to identify and quantify the most significant energy-related interactions among building subsystems; to develop the scientific and technical basis for improving energy related interactions in building subsystems; and to provide guidance to designers, owners, and builders for improving the integration of building subsystems for energy efficiency. The lead laboratory for this program is the Pacific Northwest Laboratory. A wide variety of expertise and resources from industry, academia, other government entities, and other DOE laboratories are used in planning, reviewing and conducting research activities. Cooperative and complementary research, development, and technology transfer activities with other interested organizations are actively pursued. In this report, the interactions of a water loop heat pump system and building structural mass and their effect on whole-building energy performance is analyzed. 10 refs., 54 figs., 1 tab.

  15. Radiant heat testing of the H1224A shipping/storage container

    SciTech Connect

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

    1994-05-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

    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.

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

    E-print Network

    Meckler, G.

    1985-01-01

    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...

  18. 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)

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

    2014-04-01

    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

  19. Energy and exergy analysis of a micro-compressed air energy storage and air cycle heating and cooling system

    Microsoft Academic Search

    Y. M. Kim; D. Favrat

    2010-01-01

    Energy storage systems are becoming more important for load leveling, especially for widespread use of intermittent renewable energy. Compressed air energy storage (CAES) is a promising method for energy storage, but large scale CAES is dependent on suitable underground geology. Micro-CAES with man-made air vessels is a more adaptable solution for distributed future power networks. In this paper, energy and

  20. Bidirectional thermal syphon valve, installation for the production and storage of heat or cold comprising such a thermal syphon valve, and various uses

    SciTech Connect

    Barthez, R.; Bogo, R.; Boissonnet, F.

    1985-07-30

    The invention relates to a bidirectional thermal siphon-valve operating by natural convection. It further relates to an installation for the production and storage of heat or cold comprising such a thermal siphon-valve, preferably with a continuously operating pump. The thermal siphon-valve functions to direct a heat-transfer fluid toward one of two hydraulic circuits, or to divide it between the two circuits, on the basis of its temperature. It is distinguished by the fact that it comprises an entirely internally open tubular body (14) with a vertical axis which is provided with at least one inlet orifice (10a) for the heat-transfer fluid, located substantially in its middle portion, and two outlet orifices (10b, 10c) for the heat-transfer fluid, located in its lower and upper portions, respectively.

  1. Experimental study of solid–liquid phase change in a spiral thermal energy storage unit

    Microsoft Academic Search

    J Banaszek; R Domañski; M Rebow; F El-Sagier

    1999-01-01

    A new idea on the use of a vertical spiral heat exchanger in a latent heat thermal energy storage system is analyzed experimentally. In this context, two important subjects are addressed. The first one is the temporal behavior of a phase change medium undergoing a non-isothermal solid–liquid phase change transition during its two-side heating or cooling by a working fluid

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

    NASA Astrophysics Data System (ADS)

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

    2007-01-01

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

  3. Simulation of electricity supply of an Atlantic island by offshore wind turbines and wave energy converters associated with a medium scale local energy storage

    Microsoft Academic Search

    A. Babarit; H. Ben Ahmed; A. H. Clément; V. Debusschere; G. Duclos; B. Multon; G. Robin

    2006-01-01

    The problem of sizing an electricity storage for a 5000 inhabitants island supplied by both marine renewables (offshore wind and waves) and the mainland grid is addressed by a case study based on a full year resource and consumption data. Generators, transmission lines and battery storage are accounted for through basic simplified models while the focus is put on electricity

  4. Cool Storage Performance 

    E-print Network

    Eppelheimer, D. M.

    1985-01-01

    Utilities have promoted the use of electric heat and thermal storage to increase off peak usage of power. High daytime demand charges and enticing discounts for off peak power have been used as economic incentives to promote thermal storage systems...

  5. Capric–myristic acid\\/expanded perlite composite as form-stable phase change material for latent heat thermal energy storage

    Microsoft Academic Search

    Ali Karaipekli; Ahmet Sar?

    2008-01-01

    The aim of this study is to prepare a novel form-stable phase change material (PCM) for latent heat thermal energy storage (LHTES) in buildings. A eutectic mixture of capric acid (CA) and myristic acid (MA) is incorporated with expanded perlite (EP). Thermal properties, thermal reliability, and thermal conductivity of the form-stable composite PCM are determined. The maximum CA–MA absorption of

  6. Poly(divinylbenzene) Microencapsulated Octadecane for Use as a Heat Storage Material: Influences of Microcapsule Size and Monomer\\/Octadecane Ratio

    Microsoft Academic Search

    Duangruedee Supatimusro; Supaporn Promdsorn; Sutanya Thipsit; Waraporn Boontung; Preeyaporn Chaiyasat; Amorn Chaiyasat

    2012-01-01

    Poly(divinylbenzene) (PDVB) microencapsulated octadecane (OD) (PDVB\\/OD) used as heat storage material were prepared by suspension polymerization at 70°C using benzoyl peroxide and polyvinyl alcohol as initiator and stabilizer, respectively. The influence of microcapsule size and divinylbenzene (DVB)\\/OD weight ratio on the microcapsule shape and thermal properties of encapsulated OD were considered. Thermal properties and thermal stability of PDVB\\/OD microcapsules were

  7. Epicuticular changes and storage potential of cactus pear [ Opuntia ficus-indica Miller (L.)] fruit following gibberellic acid preharvest sprays and postharvest heat treatment

    Microsoft Academic Search

    M. Schirra; G. D’hallewin; P. Inglese; T. La Mantia

    1999-01-01

    Cactus pear [Opuntia ficus-indica Mill. (L.) cv. Gialla] fruit were treated 10 weeks after the second induced-bloom flush with 10 ppm gibberellic acid (GA3) or were heated at 37°C for 30 h under saturated humidity after harvest. The two treatments were also combined before storage at 6°C for 45 days plus 4 additional days at 20°C to simulate a marketing

  8. 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)

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

    2012-02-01

    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.

  9. Investigations in cool thermal storage: storage process optimization and glycol sensible storage enhancement 

    E-print Network

    Abraham, Michaela Marie

    1993-01-01

    storage capacity due to a large decrease in the latent heat of fusion of the water in the storage solution. Carnot efficiencies, for the storage process, decrease with the lower operating temperatures. Finally, despite a fixed temperature differential...

  10. High-temperature storage battery

    SciTech Connect

    Reiss, H.; Ziegenbein, B.

    1985-05-14

    High-temperature storage battery with a double-walled housing and insulating material between the housing walls. At least one storage cell as well as a heat sink is arranged in the interior of the housing. The cooling device for the storage cell is designed as a heat exchanger and at least one and preferably several storage cells are associcated with each exchanger.

  11. Thermal storage for electric utilities

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    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.

  12. Nodal synthetic kernel (N-SKN) method for solving radiative heat transfer problems in one- and two-dimensional participating medium with isotropic scattering

    NASA Astrophysics Data System (ADS)

    Altaç, Zekeriya; Tekkalmaz, Mesut

    2013-11-01

    In this study, a nodal method based on the synthetic kernel (SKN) approximation is developed for solving the radiative transfer equation (RTE) in one- and two-dimensional cartesian geometries. The RTE for a two-dimensional node is transformed to one-dimensional RTE, based on face-averaged radiation intensity. At the node interfaces, double P1 expansion is employed to the surface angular intensities with the isotropic transverse leakage assumption. The one-dimensional radiative integral transfer equation (RITE) is obtained in terms of the node-face-averaged incoming/outgoing incident energy and partial heat fluxes. The synthetic kernel approximation is employed to the transfer kernels and nodal-face contributions. The resulting SKN equations are solved analytically. One-dimensional interface-coupling nodal SK1 and SK2 equations (incoming/outgoing incident energy and net partial heat flux) are derived for the small nodal-mesh limit. These equations have simple algebraic and recursive forms which impose burden on neither the memory nor the computational time. The method was applied to one- and two-dimensional benchmark problems including hot/cold medium with transparent/emitting walls. The 2D results are free of ray effect and the results, for geometries of a few mean-free-paths or more, are in excellent agreement with the exact solutions.

  13. Development of a practical photochemical energy storage system. Annual report, June 15, 1976June 14, 1977. [Interconversion between norbornadiene and quadricyclene for thermochemical heat storage

    Microsoft Academic Search

    R. R. Hautala; C. R. Kutal

    1977-01-01

    Significant progress toward the development of a solar energy storage system based on the norbornadiene-quadricyclene interconversion has been achieved during the past year. New sensitizers and catalysts have been discovered and conditions found where single cycles of the photosensitization step and the catalytic reversion step appear to be quantitative. Both sensitizers and catalysts have been successfully incorporated onto insoluble polymeric

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    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.

  15. Sensible heat receiver for solar dynamic space power system

    NASA Technical Reports Server (NTRS)

    Perez-Davis, Marla E.; Gaier, James R.; Petrefski, Chris

    1991-01-01

    A sensible heat receiver is considered which uses a vapor grown carbon fiber-carbon (VGCF/C) composite as the thermal storage medium and which was designed for a 7-kW Brayton engine. This heat receiver stores the required energy to power the system during eclipse in the VGCF/C composite. The heat receiver thermal analysis was conducted through the Systems Improved Numerical Differencing Analyzer and Fluid Integrator (SINDA) software package. The sensible heat receiver compares well with other latent and advanced sensible heat receivers analyzed in other studies, while avoiding the problems associated with latent heat storage salts and liquid metal heat pipes. The concept also satisfies the design requirements for a 7-kW Brayton engine system. The weight and size of the system can be optimized by changes in geometry and technology advances for this new material.

  16. Use of a serum-free medium for long-term storage of human corneas. Influence on endothelial cell density and corneal metabolism

    Microsoft Academic Search

    Britta Hempel; Jürgen Bednarz; Katrin Engelmann

    2001-01-01

    Background: The success of long-term corneal organ culture is limited by the progressive loss of endothelial cells during culture and the use of culture medium supplemented with fetal calf serum as a possible source of contamination with infectious agents. In this study, we investigated the suitability of a serum-free medium (Endothelial-SFM) to improve preservation conditions for human donor corneas. Methods:

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

    PubMed

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

    2013-07-01

    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

  18. SERI solar energy storage program

    Microsoft Academic Search

    R. J. Copeland; J. D. Wright; C. E. Wyman

    1980-01-01

    Research on advanced technologies, system analyses, and assessments of thermal energy storage for solar applications in support of the Thermal and Chemical Energy Storage program are presented. Currently, research is in progress on direct contact latent heat storage and thermochemical energy storage and transport. Systems analyses are being performed of thermal energy storage for solar thermal applications, and surveys and

  19. International Energy Conference, 19 -21 May 2003 Energy Technologies for post-Kyoto targets in the medium term

    E-print Network

    Aquifers and Hydrocarbon Structures Power & Heat Air Air O2 N2 & O2 CO2 CO2 CO2 Compression & DehydrationInternational Energy Conference, 19 - 21 May 2003 Energy Technologies for post-Kyoto targets in the medium term CO2 Capture & Geological Storage Niels Peter Christensen International Ventures Director

  20. 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

    Glatzmaier, G.

    2011-08-01

    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.