传热不可逆及对有机朗肯循环影响热力学分析  

Thermodynamic analyses of heat transfer irreversibility and its effects on organic Rankine cycle

作　　者：李新国[1,2] 吴晓松[1,2] 王竞逸 LI Xin-guo;WU Xiao-song;WANG Jing-yi(School of Mechanical Engineering,Tianjin University,Tianjin 300350,China;Key Laboratory of EfficientUtilization of Low and Medium Grade Energy,Ministry of Education,Tianjin 300350,China)

机构地区：[1]天津大学机械工程学院,天津300350 [2]中低温热能高效利用教育部重点实验室,天津300350

出　　处：《化学工程》2019年第4期34-39,共6页Chemical Engineering(China)

基　　金：国家自然科学基金资助项目(51276122)

摘　　要：提出建立传热匹配度与传热不可逆度,并结合生态学函数对有机朗肯循环进行分析。基于模拟有机朗肯循环的梯形循环,建立循环性能(净功、热效率、■效率和生态学函数)与传热不可逆性(不可逆度与传热匹配度)之间的数学关系,研究传热不可逆对循环性能的影响。结果表明:基于工质热源转折温度,无极值循环的循环性能高于有极值循环。生态学函数综合反映了系统的循环性能与不可逆损失的输出净效益,可作为评价、选择热力循环、工质筛选及合理运行工况的新方法、指标。Parameters of matching degree of heat transfer(MDHT)and irreversible degree of heat transfer(IDHT)were proposed and built,and the organic Rankine cycle(ORC)were analyzed,combined with ecological function.Based on trapezoidal cycle which was proposed to simulate ORC,mathematical relations between cycle performance(net power output,thermal efficiency,exergy efficiency and ecological function)and heat transfer irreversibility(IDHT and MDHT)were established;effects of heat transfer irreversibility on performance of ORC were investigated.The results show that cycle performance with monotonic increase is higher than that with the maximum value base on shift-temperature of heating fluid for working fluid.Ecological function comprehensively reflects the net output effect of cycle output and system irreversible loss;and it can be used as a new method or criterion to evaluating or selecting the thermodynamic cycles,working fluids and suitable operation conditions.

关 键 词：有机朗肯循环 梯形循环 传热不可逆 传热匹配度 生态学函数 工质热源转折温度 

分 类 号：TK123[动力工程及工程热物理—工程热物理]