制冷工质在低温发电中的热力学分析  

Thermodynamic analysis on low temperature power generation using refrigerant as working media

作　　者：马一太[1] 龚文瑾[1] 李敏霞[1] 

机构地区：[1]天津大学热能研究所,天津300072

出　　处：《热科学与技术》2009年第3期248-254,共7页Journal of Thermal Science and Technology

摘　　要：基于常规能源日益稀少,环境污染日益严重,主要研究开发利用太阳能来进行低温发电。采用了CO2、R123、R134a、R290、R600、R236fa、R245fa、NH3等8种常用的制冷剂,选用等工况(same working condition,SWC)和最佳蒸发压力(optimal evaporating pressure,OP0)两种研究方法,分析各个工质的循环特性。并以CO2的跨临界循环和R134a的亚临界循环为例,进行分析,对比了不同太阳辐射量和工质质量流量下效率、温度及膨胀比的变化。结果表明,CO2的膨胀比最小,膨胀性能优于其他7种工质,最差的为R245fa。OP0法的计算方法只适用于亚临界循环,不适用于跨临界循环。在进行非常规循环(跨临界循环)与常规循环(亚临界循环)热源条件变化的对比中,SWC法更有说服力。The low temperature electricity generation utilizing the solar energy was studied, based on the lower conventional energy source and the serious environmental pollution nowadays. The cycle performances of eight refrigerants such as CO2, R123, and R134a were analyzed, using two research methods SWC （Same Working Condition） and OP0 （Optimal evaporator Pressure）. The variety of temperature and expansion ratio along with the changing of solar radiation and flow rate was compared, taking the CO2 transcritical cycle and the R134a subcritical cycle for examples. It is shown that expansion ratio of CO2 is the lowest, expansion performance of COz surpasses the other 7 refrigerants, but R245fa is the worst one. OP0 method can only be used in subcritical cycle and not suit for transcritical cycle. Therefore, SWC method is more persuasive in the contrast between the non-conventional cycle （transcritical cycle） and the conventional cycle （subcritical cycle）, as the heat source condition changes.

关 键 词：CO2 低温发电 发电效率 泵功效率 膨胀性能 

分 类 号：TK612[动力工程及工程热物理—生物能]