发动机排气余热换热器传热窄点研究  

An Investigation on Heat Transfer Pinch Point of Engine Exhaust Heat Exchanger

作　　者：李晓宁[1] 舒歌群[1] 田华[1] 卫海桥[1] 王之东[2] 

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072 [2]天津大学天津内燃机研究所,天津300072

出　　处：《工程热物理学报》2012年第12期2058-2062,共5页Journal of Engineering Thermophysics

基　　金：国家重点基础研究发展计划"973"资助项目(No.2011CB707200)

摘　　要：本文以发动机排气余热回收有机朗肯循环系统排气换热器窄点为研究对象,针对亚临界有机朗肯循环系统中排气换热器窄点位置确定方法的不足之处,提出了一种简单快捷的确定窄点位置的新方法-平衡点法。选取R123为工质,对不同窄点温差下的各循环参数进行计算,得到了各参数值。结果表明:随着窄点温差取值的增大,换热面积与换热量等循环参数都呈减小趋势,并且在较小窄点温差值变动时对上述参数影响更加显著。传热窄点温差的取值要综合考虑传热效果、系统性能与经济性因素。This paper presents an investigation on pinch point temperature difference （PPTD） of exhaust heat exchanger used in engine exhaust waste heat recovery system. Equilibrium point analysis method is proposed, which is a simple and efficient new method to determine the location of the pinch point, because of the inadequacies of the method currently used in the subcritical organic Rankine cycle system. The parameter values are achieved by calculating the programs under different values of PPTD using R123 as working fluid, and some conclusions can be drawn by analyzing the calculating results. The values of heat exchange area, heat transfer rate and other cycle parameters decline with the increase of the values of PPTD, which have a remarkably impact on these parameters especially as the values that are employed are not very big. The appropriate value that is selected depends mainly on the efficiency of heat transfer, the performance of the organic Rankine cycle system and economical factor.

关 键 词：排气换热器 窄点温差 有机朗肯循环 

分 类 号：TK212[动力工程及工程热物理—动力机械及工程]