共查询到20条相似文献,搜索用时 15 毫秒
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Yukitaka Kato Norimichi Yamashita Kei Kobayashi Yoshio Yoshizawa 《Applied Thermal Engineering》1996,16(11):853-862
A kinetic study of the hydration of magnesium oxide was performed to test the possibility of developing a magnesium oxide/water chemical heat pump. The hydration rate of magnesium oxide was measured by a gravimetric analysis with a sample of average particle size 10 μm for the reaction temperature 373–423 K and the reaction vapor pressure 12.3–47.4 kPa. It was a reasonable hypothesis that the reactant magnesium oxide had four reaction regimes. An empirical rate equation based on this hypothesis was proposed with parameters determined from experimentally measured values. The performance of the heat pump was estimated numerically using the rate equation. The heat output rate was large enough in comparison with other common heat pumps. It was shown that the reaction system would be applicable to a chemical heat pump system. 相似文献
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A chemical heat pump using hydration of magnesium oxide in a three-phase reactor is proposed. Magnesium oxide particles suspended in the triethylene glycol are hydrated exothermally by introducing water vapour. The hydration rate was measured under the temperatures ranging from 383 K to 523 K. It was found that the reaction rate was proportional to the amount of adsorbed water molecules, and correlated in an equation. 相似文献
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Selahattin Gktun 《国际能源研究杂志》1998,22(14):1299-1304
An irreversible heat engine-driven vapour compression and absorption heat pump system is considered as a cogeneration cycle. The effects of thermal resistances and internal irreversibilities on the coefficient of performance (COP) of this cogeneration cycle were investigated using finite-time thermodynamic approach. An improved equation for the COP of the system under consideration was obtained. The results obtained here may serve as a good guide for the evaluation of existing real cogeneration heat pumps or provide some theoretical bases for the optimal design of future cogeneration heat pumps. © 1998 John Wiley & Sons, Ltd. 相似文献
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For this heat pump kinetic study, the dehydration rate of tert-butanol (an endothermic reaction) was measured under conditions suitable for operating a chemical heat pump. The proposed Langmuir-Hinshelwood rate equation agreed well with the experimental rate data. The heat pump kinetic study was examined in a batchwise operation by using both the endothermic reaction rate equation and a previously proposed rate equation for the exothermic reaction. Although the endothermic reaction rate was suitable for a heat pump, an improvement of the endothermic reaction rate was desired since it was found to be too slow. The endothermic reaction was about 5 to 20 times slower than the exothermic reaction. The absorbed and released heat rates per batch cycle were almost the same as for conventional heat pumps. 相似文献
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Shin'ya Obara 《国际能源研究杂志》2007,31(13):1275-1291
A chromosome model that simulates the operation patterns of an energy system was introduced into a simple Genetic Algorithm, and a method of dynamic optimization was developed. This paper analyses the operation planning of an energy system that uses in combination a solar power module, proton‐exchange membrane fuel cell cogeneration (PEMFC‐CGS) with methanol steam reforming, a geo‐thermal heat pump, heat storage and battery, commercial power, and a kerosene boiler. The hours of operation of each energy device and the rate of the energy output were calculated by having introduced the analysis program developed by this study. Three objective functions: (a) minimization of operation cost; (b) minimization of the error of demand‐and‐supply balance; and (c) minimization of the amount of greenhouse gas discharge were given to the optimization analysis of the system. Furthermore, the characteristics of the system operation planning under each objective function are described. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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The thermal performance of a chemical heat pump that uses the reaction system of calcium oxide/lead oxide/carbon dioxide, which is developed for utilization of high‐temperature heat above 800°C, is studied experimentally. The thermal performance of a packed‐bed reactor of a calcium oxide/carbon dioxide reaction system, which stores and transforms a high‐temperature heat source in the heat pump operation, is examined under various heat pump operation conditions. The energy analysis based on the experiment shows that it is possible to utilize high‐temperature heat with this heat pump. This heat pump can store heat above 850°C and then transform it into a heat above 900°C under an approximate atmospheric pressure. An applied system that combines the heat pump and a high‐temperature process is proposed for high‐efficiency heat utilization. The scale of the heat pump in the combined system is estimated from the experimental results. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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The performance simulation of heat recovery steam generators in a cogeneration system has been investigated to see the effect of pinch and approach points on steam generation and also on temperature profiles across the heat recovery steam generator. The effects of operating conditions on steam production and also on exit gas temperature from the heat recovery steam generator are discussed. Low pinch point results in improved heat recovery steam generator performance due to reduced irreversibilites. The supplementary firing enhances the steam production. © 1998 John Wiley & Sons, Ltd. 相似文献
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水环热泵空调系统应用性分析 总被引:1,自引:0,他引:1
水环热泵空调系统是小型水/空气热泵机组的一种应用。通过连通建筑物周边区和内区的水循环环路将小型水/空气热泵机组并联在一起,形成一个封闭环路,将建筑物内区制冷产生的冷凝热转移到周边区,作为周边区热泵的低温热源。水环热泵空调系统在对建筑物内区供冷的同时实现对周边区供热,使建筑物空调的内、外区冷热相抵,建筑物内部余热得到充分利用,节约了能源。本文比较了水环热泵系统相对于常规空调系统在系统结构、节省能源等方面的优势和应用中遇到的问题,并结合工程应用实例,分析了水环热泵空调系统的经济性。 相似文献
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In the paper, a method for the determination of the parameters of the units, stationary operating in a multi-unit heat pump system, is presented. This method is used for the consideration of six schemes of hydraulic connection of the heat exchangers in groups. 相似文献
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《Energy》2005,30(11-12):2144-2155
A chemical heat pump using a magnesium oxide/water reaction system is expected to be applicable to cogeneration systems using gas engine, diesel engine, and fuel cells. The operability of the heat pump was examined experimentally under hydration operation pressures between 30 and 203 kPa. In the experiment, a reactant having high durability for repetitive operation was packed in a cylindrical reactor. The cycle of operation was repeated under various thermally driven operation conditions. The forward and reverse reactions were studied by measuring the reactor bed temperature distribution and the reacted fraction changes. The reactor bed stored heat at around 300–400 °C by the dehydration reaction and released heat at around 100–200 °C by the hydration reaction under the heat amplification mode operation. The practical possibility of the reactor bed was discussed based on the experimental results. The heat pump is expected to be applicable for load leveling in a cogeneration system by chemically storing surplus heat during low heat demand and supplying heat during peak demand. It was shown that the chemical heat pump would be able to improve the efficiency of energy utilization in cogeneration systems while also helping to reduce energy consumption and global carbon dioxide emissions. 相似文献
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电储热技术是当前适应煤改电环保需求和清洁供暖发展趋势的一项新技术,各种温度级别的储热材料均存在,根据需求选择并制备材料,进而设计电热储能的系统结构成为储热研究关键内容。本文针对蓄热材料的热性能进行了应用特性研究,分析并提出一种蓄热材料温度体系,并对高温蓄热材料应用特点进行了系统设计分析与比较,提出一种基于特制氧化镁的电阻式蓄热系统设计方法,并分析其特点。 相似文献
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污水源热泵系统的工程应用 总被引:1,自引:1,他引:0
污水源热泵系统以污水作为热源/热汇,通过热泵机组将污水中难以直接利用的热能提取出来。结合大型工程实例的设计及建设,依照系统的运行流程提出了工程各个部分的设计和建设中的要点问题。分析了系统流程,介绍了污水源的水量、水温的保证,取排水的建设,换热器的选择,热泵机房的设计。 相似文献
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This paper deals with an optimization problem about thermal exchanges between a reactive porous environment and two networks of heat pipes together enclosed in a chemical heat pump reactor. Because all physico‐chemical features of the reactive matter are fixed (actually the reactor contains a patented chemical mixture), the only way to optimise the quality of these exchanges, is to find an optimal location within the reactor for the heat pipes using ozone friendly fluid as the working fluid. Two numerical approaches, the first quantitative by the finite element method and the second based on the heat conduction hyperbolic theory, enabled us to obtain the same optimization results. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
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沼气发动机驱动的热泵能源利用率计算 总被引:2,自引:0,他引:2
沼气发动机驱动的热泵(BHP)是一种节能环保型装置,与电动压缩式热泵相比,其主要动力源不同.该装置能充分回收利用沼气发动机余热.通过对BHP系统的构建及一次能源利用率(PER)的计算,分析了BHP系统的经济性及其对环境保护的作用.结果表明:不论从节能还是从环保方面考虑,BHP系统都具有明显的经济价值和环保效益. 相似文献
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化学热泵是高效,环保的新型能源技术,在余热回收,储热,可再生能源等领域具有广泛的应用前景.本文综述了化学热泵系统的一般理论和在储热技术中的应用,介绍了化学热泵系统技术在反应与工质对选择,传热强化以及工业研究与应用等方面的发展. 相似文献