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本文通过任意热力过程的Yong损失分析,导出热力循环的总Yong损失EL的计算式,说明任意热力循环的Yong损失EL只能是大于零或者等于零。符合卡诺定理和热力学第二定律。 相似文献
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介绍了提升工业废热温位的吸收式热变换器的工作原理 ,工质的热力循环过程。应用热力学第二定律和工质的热力学性能数据 ,分别对工质的理论循环过程与实际循环过程的性能系数进行了理论分析和计算 ,研究了操作参数对性能系数和温升的影响规律 相似文献
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应用有限时间热力学理论对吸收式热泵进行研究,将其等效为一个由不可逆卡诺热机驱动的不可逆卡诺热泵的联合循环系统,考虑了热阻及工质内部的不可逆性,建立了四热源吸收式热力循环模型,得出吸收式热泵的性能界限及取得性能界限的途径;并得出了吸收式热泵热力循环各个关键参数的通用优化关系,结果表明:两个等效循环的不可逆程度对系统最优性能的影响不同,在设计机组时,减小等效热泵循环的摩擦、热损失、内部耗散比减小等效热机循环之间的相应损失更能显著提高机组的性能;并指出吸收器与冷凝器的热分配率是热力循环优化的结果,指出以往研究者将热分配率定义为一个独立变量而得到的分析结果均不具有普遍适用性。 相似文献
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中国工程热物理学会1983年度学术活动计划基本确定。今年上半年,将在北京、合肥等地组织工程热物理学数值计算和计算程序应用学习交流班;还将召开一次核反应堆热工流体传热讨论会。今年下半年将在北京、哈尔滨等地召开工程热力学热力循环专题讨论会、热管学术和技术讨论会、能源工作座谈讨论会。今年四季度将在西安召开250人规模的中国工程热物理学会第四届学术年会,并同时召开理事会和编委会。热烈欢迎工程热物理专家和科技工作者大力支持和积极参加这些学术活动。参加的征文可寄北京市 相似文献
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HAT循环是一种先进的热力循环,具有高效率、高比功、低花费、低污染的良好性能,被誉为21世纪最有竞争力的动力循环。本文综述了HAT循环的关键部件饱和器的研究概况,指出了目前饱和器研究的一些成果和今后研究的重点。 相似文献
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An endoreversible closed modified simple Brayton cycle model with isothermal heat addition coupled to variable-temperature heat reservoirs is established using finite-time thermodynamics. Analytical expressions of dimensionless power output, thermal efficiency, dimensionless entropy generation rate and dimensionless ecological function are derived. Influences of cycle thermodynamic parameters on ecological performance and optimal compressor pressure ratio, optimal power output, optimal cycle thermal efficiency and optimal entropy generation rate corresponding to maximum ecological function are obtained and compared with those corresponding to maximum power output. The results show that cycle thermal efficiency improvement and entropy generation rate reduction are obtained at the expense of higher compressor pressure ratio and a little sacrifice of power output at maximum ecological function. The compromises between power output and entropy generation rate and between power output and cycle thermal efficiency, respectively, are achieved. 相似文献
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The first and second laws of thermodynamics were used to analyze a novel thermodynamic cycle proposed by Goswami in 1995 that uses an ammonia–water binary mixture as the working fluid, while producing both power and refrigeration simultaneously. The thermodynamic performance of the cycle was optimized for maximum second law efficiency using a commercially available optimization program. A maximum second law efficiency of 65.8% was obtained at a heat source temperature of 420 K. An exergy analysis was performed to study losses in different components of the cycle. It is seen that the largest contribution to cycle irreversibility comes from the absorber, with the rectifier and solution heat exchanger also contributing significantly. Irreversibility generation in the boiler is high at very low heat source temperatures, but drops at higher temperatures. 相似文献