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المؤلفون: J. Huang, D. S. Zhu, Liejin Guo, D. D. Joseph, Y. Matsumoto, Y. Sommerfeld, Yueshe Wang
المصدر: AIP Conference Proceedings.
مصطلحات موضوعية: Computer simulation, Chemistry, Thermal, Heat transfer, Thermal power station, Mechanical engineering, Mechanics, Sensible heat, Thermal energy storage, Energy storage, Isothermal process
الوصف: 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.
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المؤلفون: V. Vasudeva Rao, Shyamalendu M. Bose, S. N. Behera, B. K. Roul
المصدر: AIP Conference Proceedings.
مصطلحات موضوعية: Superconductivity, Materials science, Condensed matter physics, Superconducting magnet, Superconducting magnetic energy storage, Energy storage
الوصف: This paper gives an Introduction to Superconducting Magnetic Energy Storage (SMES) systems and their applications along with an overview of their present status. Further a brief description to a Micro SMES/UPS system of 0.5 MJ capacity that was developed/tested at IIT, Kharagpur is also included.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_________::bf9f23f79e26b1b1f3194598b807197d
https://doi.org/10.1063/1.3027184 -
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المؤلفون: David S. Wolford, Christopher J. Crowley, David M. Wilt, Donald L. Chubb, Patrick J. Magari
المصدر: AIP Conference Proceedings.
مصطلحات موضوعية: Photovoltaic thermal hybrid solar collector, Engineering, business.industry, Distributed generation, Photovoltaic system, Electrical engineering, Energy transformation, business, Thermal energy storage, Solar energy, Energy storage, Solar power, Automotive engineering
الوصف: Thermophotovoltaic (TPV) energy conversion has long been considered a potential replacement for thermoelectrics in radioisotope powered deep space power systems. In this application, TPV offers significant potential improvements in both efficiency and mass specific power (W/kg), performance which is considered mission enabling for a variety of mission concepts. TPV systems powered by concentrated solar energy have also been proposed for inner planetary solar system missions. This concept takes advantage of TPV’s ability to store energy for shadow periods in the form of heat energy rather than as electrical energy (batteries), as is commonly done for photovoltaic power systems. The simplicity and large number of power cycles offered by the thermal energy storage offers potential system benefits compared to a photovoltaic / battery system. Recent efforts in the development of radioisotope TPV (RTPV) at Creare have resulted in the demonstration of converter efficiencies in excess of 19%. Several independent system mass analyses have been performed for the Creare RTPV system and they predict specific powers above 10W/kg at the system level. Trades have suggested increasing the rejection temperature can result in a 50% reduction in radiator area while only suffering a 15% reduction in mass specific power.
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المؤلفون: M. Pauken, Brenda Watkins, Nick Emis
المصدر: AIP Conference Proceedings.
مصطلحات موضوعية: chemistry.chemical_compound, Materials science, Thermal conductivity, Temperature control, Chemical engineering, chemistry, Lithium nitrate, Zinc nitrate, Carbon nanofoam, Thermodynamics, Thermal stability, Thermal energy storage, Energy storage
الوصف: This paper describes recent technology developments in thermal energy storage devices for use on spacecraft for thermal control of electronic components requiring thermal stability. A thermal energy storage module has been designed, built and tested using lithium nitrate as the melt material and carbon foam as the conductive filler. For this unit the observed melt temperature was around 30 °C. The supercooling property of lithium nitrate was reduced by adding zinc nitrate as a catalyst. The hydrophobic nature of the carbon foam was overcome by adding a surfactant to the lithium nitrate. The resulting energy storage capacity of the prototype module during the melt was 40 W‐hr/kg. There was very good thermal conductivity through the module resulting in very low temperature gradients even at high power levels.
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المؤلفون: Masakazu Sugiyama, Yoshiaki Nakano
المصدر: AIP Conference Proceedings.
مصطلحات موضوعية: Solar chemical, Waste management, Environmental science, Energy storage
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المصدر: AIP Conference Proceedings.
مصطلحات موضوعية: Superconductivity, Magnetization, Materials science, Room-temperature superconductor, Condensed matter physics, Electrical resistivity and conductivity, Transition temperature, Superconducting magnetic energy storage, Critical field, Magnetic field
الوصف: We report the study of temperature and magnetic field dependence of magnetization and resistivity of Mo52Re48 alloy superconductor. The transition temperature (TC) and zero temperature limit upper critical field (HC2(0)) are estimated to be about 13.4 K and 8.5 T which are higher than those for any Mo-Re alloys reported in literature. The critical current density is estimated to be about 6.2 × 108 A/m2 at 2 K which is nearly comparable to most of the commercial superconductors. These properties indicate that if tuned properly Mo-Re system may be useful for the high field application.
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المؤلفون: Robert S. Janesheski, Steven F. Son, Lori J. Groven
المصدر: AIP Conference Proceedings.
مصطلحات موضوعية: chemistry.chemical_classification, Materials science, Composite number, Poling, Polymer, Energetic material, Piezoelectricity, Energy storage, law.invention, Ignition system, chemistry.chemical_compound, chemistry, law, Fluoropolymer, Composite material
الوصف: The ability to sensitize a nanoaluminum/piezoelectric polymer composite has been studied using two fluoropolymer systems (THV220A and FC-2175). Reactive composite samples of the nanoaluminum/polymer were made into thin sheets and their ability to store energy and exhibit piezoelectric properties was measured. Also, initial drop weight impact tests were performed on the samples and results showed the piezoelectric energetic composites failed to ignite at a given impact energy unless sensitized. When a DC voltage was applied to the sample, the materials ignited at the same impact energy where previous ignition failed. Results indicate that the reactive composites may have been sensitized by storing the applied charge. The application of a DC voltage may also have an effect on the piezoelectric properties of the energetic composites similar to the way poling techniques work. Further work is planned to investigate what parameters are inducing the sensitization of the material. A better understanding could lead to applications where switching or tuning the sensitization of an energetic material is beneficial.
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المؤلفون: H. Abdullah, A. N. Darus, A. F. Jalaludin, N. A. Alkahli
المصدر: AIP Conference Proceedings.
مصطلحات موضوعية: Organic Rankine cycle, Engineering, Rankine cycle, Waste management, business.industry, Nanofluids in solar collectors, Solar energy, Thermal energy storage, law.invention, Photovoltaic thermal hybrid solar collector, Solar air conditioning, law, Parabolic trough, business, Process engineering
الوصف: The conceptual design of an Organic Rankine Cycle (ORC) driven by solar thermal energy is developed for the decentralized production of electricity of up to 50 kW. Conventional Rankine Cycle uses water as the working fluid whereas ORC uses organic compound as the working fluid and it is particularly suitable for low temperature applications. The ORC and the solar collector will be sized according to the solar flux distribution in the Republic of Yemen for the required power output of 50 kW. This will be a micro power generation system that consists of two cycles, the solar thermal cycle that harness solar energy and the power cycle, which is the ORC that generates electricity. As for the solar thermal cycle, heat transfer fluid (HTF) circulates the cycle while absorbing thermal energy from the sun through a parabolic trough collector and then storing it in a thermal storage to increase system efficiency and maintains system operation during low radiation. The heat is then transferred to the organic fluid in the ORC via a heat exchanger. The organic fluids to be used and analyzed in the ORC are hydrocarbons R600a and R290.
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المؤلفون: John G. Brisson, Charles L. Hannon, Jake Hogan, Brady Krass
المصدر: AIP Conference Proceedings.
مصطلحات موضوعية: Physics, business.industry, Passive cooling, Nuclear engineering, Active cooling, Electrical engineering, Refrigeration, Cryogenic energy storage, Liquid oxygen, Cryocooler, Cryogenic fuel, business, Liquid hydrogen
الوصف: Future lunar and planetary explorations will require the storage of cryogenic propellants, particularly liquid oxygen (LOX) and liquid hydrogen (LH2), in low earth orbit (LEO) for periods of time ranging from days to months, and possibly longer. Without careful thermal management, significant quantities of stored liquid cryogens can be lost due to boil-off. Boil-off can be minimized by a variety of passive means including insulation, sun shades and passive radiational cooling. However, it has been shown that active cooling using space cryocoolers has the potential to result in Zero Boil-Off (ZBO) and the launch-mass savings using active cooling exceeds that of passive cooling of LOX for mission durations in LEO of less than 1 week, and for LH2 after about 2 months in LEO. Large-scale DC-flow cryogenic refrigeration systems operate at a fraction of the specific power levels required by small-scale AC-flow cryocoolers. The efficiency advantage of DC-flow cryogenic cycles motivates the current development of a cryocooler based on a modification of the Collins Cycle. The modified Collins cycle design employs piston type expanders that support high operating pressure ratios, electromagnetic valves that enable "floating pistons", and recuperative heat transfer. This paper will describe the design of a prototype Modified-Collins cryocooler for ZBO storage of cryogenic fuels in space.
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المؤلفون: Colin Wilson, Eric Marquardt, Paul Hendershott, Robert Levenduski, Wilfred Gully, Ted Bertele, Dave Glaister
المصدر: AIP Conference Proceedings.
مصطلحات موضوعية: Engineering, business.industry, Nuclear engineering, Electrical engineering, chemistry.chemical_element, Shields, Refrigeration, Cryocooler, Thermal energy storage, Power (physics), Neon, chemistry, Active cooling, Thermal, business
الوصف: Ball Aerospace and Redstone Aerospace are developing a space cryocooler for cooling complex optical systems whose loads are intermittent. An example of such a system would be an Earth observation satellite that images for only a fraction of its orbit. If a cooler can store refrigeration during the lull and provide it when the system is active, the cooler can be considerably smaller than one sized to provide the full load continuously. Our cooler provides two stages of refrigeration, a stage of intermittent cooling at 35 K for a focal plane assembly and a stage of continuous cooling at 85 K for the surrounding thermal shields. The cooler provides the intermittent cooling by collecting liquid neon in a unique internal thermal storage tank and forwarding it to the focal plane when the heat loads are high. Our paper presents extensive performance data for neon at 35 K. It carries 2 W at 35 K for 30 minutes plus the 8.5 W of continuous cooling at 85 K for less than 300 W DC power. It is ready to cool again in an hour. For contrast, the same hardware was filled with nitrogen and tested at 82 K. It carries 5 W for 25 minutes plus 15 W of continuous cooling at 130 K for less than 220 W DC power. It is ready to cool again in a little over an hour. The system has many features for space system compatibility. Because the storage is located within an active control loop, the cooler can maintain the 35 K interface temperature to better than ± 0.1 K. Because it circulates liquid it can be located remotely, which solves many compatibility issues. And with careful liquid management, it can work in any orientation and in 0-g. In this paper our flight like equipment will be described, and its continuing evolution to flight will be discussed.
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