一种乏气压缩再循环有机朗肯循环系统热力特性分析  

Thermodynamic Characteristics Analysis for an ORC System With Exhaust Gas Compression Recycling

作　　者：杨新乐[1] 卜淑娟 李惟慷[1] 苏畅[1] 戴文智[1] 计志鑫 黄菲菲[1] YANG Xinle;BU Shujuan;LI Weikang;SU Chang;DAI Wenzhi;JI Zhixin;HUANG Feifei(School of Mechanical Engineering,Liaoning Technical University,Fuxin 123000,Liaoning Province,China)

机构地区：[1]辽宁工程技术大学机械工程学院

出　　处：《中国电机工程学报》2020年第3期886-896,共11页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51574136);辽宁省’兴辽英才计划’项目资助(XLYC1807150);辽宁省教育厅支持项目(LJ2019QL003)~~

摘　　要：为使蒸汽余热更高效转化为有用功,在简单有机朗肯循环(organic Rankine cycle,ORC)基础上,利用乏气增压装置,并对冷凝器内部空间重新布置,提出一种新型乏气压缩再循环ORC系统(compression recycling,CR-ORC)。以423.15K余热蒸汽为热源,选取5种低沸点有机工质,采用Aspen Plus软件对简单ORC系统和CR-ORC系统进行模拟,并对模拟结果进行对比分析。结果表明,提高蒸发压力p3可有效提高两系统的热力性能,且当p3=1.5MPa时,采用工质R600a的CR-ORC系统总输出功较简单ORC系统可高出7589kW;受不同工质临界温度影响,工质R123的最佳驱动压力p7为0.6MPa,而其他4种工质最佳驱动压力p7为0.7MPa,且在最佳p7下,采用工质R600a可获得最大总输出功22663kW,最大循环热效率和㶲效率分别为22.6%、77.2%;在CR-ORC系统中,随乏气分流系数a增加冷凝器㶲损失逐渐减少,当a大于0.3时,冷凝热完全被回收利用,若采用R123作为工质,系统较简单ORC系统最高可减少7786kW的冷凝器㶲损失。In order to convert waste heat of steam into useful work with higher efficiently,a novel system combined organic Rankine cycle(ORC)with exhaust gas compression recycling(CR-ORC)was proposed by adding exhaust gas pressurizing device on simple ORC and rearranging the internal space of condenser.Using waste heat steam at 423.15K as heat source,simulating simple ORC and CR-ORC system by Aspen Plus software,and the simulation results were compared and analyzed.The results show that increasing evaporation pressure p3 can effectively improve the thermal performance of systems,and when p3=1.5MPa,the output work of CR-ORC system with working fluid R600a is 7589kW higher than that of simple ORC system.Under the influence of the critical temperature of different working fluids,the optimum driving pressure p7 of R123 is 0.6MPa,the optimum driving pressure p7 of the other working fluids is 0.7MPa,and the maximum output work of 22663kW can be obtained by using R600a.The maximum thermal efficiency and exergy efficiency were 22.6%and 77.2%.In CR-ORC system,the condenser exergy loss decreases gradually with the increase of exhaust gas diversion coefficienta.Whenais greater than 0.3,the condensation heat is completely recovered.If R123 is used as working fluid,The simple ORC system can reduce the condenser exergy loss of 7786kW.

关 键 词：有机朗肯循环 乏气压缩再循环 冷凝器 Aspen Plus 热力分析 

分 类 号：TK11[动力工程及工程热物理—热能工程]