梯级换热有机朗肯循环发电系统热力性能分析  

Thermal performance analysis for a cascade heat exchange power generation system based on ORC

作　　者：伍亚[1] 岳晨[1] 朱帮守 

机构地区：[1]南京航空航天大学能源与动力学院,江苏南京210016

出　　处：《热力发电》2017年第5期21-26,共6页Thermal Power Generation

基　　金：国家自然科学基金项目(51506090);江苏省自然科学基金项目(BK20130799)~~

摘　　要：为了充分提高低品位热源回收利用率,降低热源排放温度,本文提出了一种基于有机朗肯循环(ORC)的梯级换热发电系统。系统以地热水为热源,以循环净功率为目标函数,根据热力学第一、第二定律,采用MATLAB软件调用REFPROP编制计算程序进行参数优化,以非共沸混合物作为循环工质对系统进行热力性能分析,并与基本ORC发电系统性能进行比较。结果表明:在最优工况下,基于ORC梯级换热发电系统可有效减小工质与热源在换热过程中的平均换热温差,减少换热不可逆损失,并降低了热源排放温度,提高了热源使用率;在所选工质中,基于ORC梯级换热发电系统热力性能均优于基本ORC发电系统,循环净功率和?效率最大可提高16.07%;选择R601/R236ea为工质时,基于ORC梯级换热发电系统性能最佳。To fully enhance the recovery and utilization rate of low grade source and lower the heat source emission temperature, a cascade heat exchange power generation system based on organic Rankine cycle （ORC） was proposed. With geothermal water serving as the heat source net power output as the objective function, this system＇s parameters were optimized by self-programed calculation algorithm using the REFPROP in Matlab, according to the first and second law of thermodynamics. Moreover, thermal performance of the system was analyzed by taking the non azeotropic mixture as the circulating working fluid, and the results were compared with the thermal performance of the basic ORC system. The results show that, under the optimal working conditions, the ORC-based cascade heat exchange thermal power system can effectively reduce the mean heat transfer temperature difference between the heat source and the working fluid, which results in less irreversible loss of heat transfer and a drop in the heat source emission temperature. When both the system adopt the selected working fluids, the thermal performance of this ORC-based cascade heat exchange power generation system is better than that of the basic ORC system, its net power output and exergy .efficiencies can be increased by 16.07% at the most. When using R601/R236ea as the working fluid, this ORC-based cascade heat exchange power generation system will achieve the optimum thermal performance.

关 键 词：有机朗肯循环 地热能 梯级换热 非共沸混合物 参数优化 最大循环净功率 

分 类 号：TK01[动力工程及工程热物理] TK05