气液分离双压有机朗肯循环系统的热力学分析及优化

Thermodynamic Analysis and Optimization in Doublepressure Organic Rankine Cycle with a Gas-liquid Separator

综合非共沸工质和汽液分离技术的优势，提出一种非共沸工质的DSORC（有机朗肯循环）汽液分离双压流程系统，并建立非共沸工质DSORC的参数优化模型，优化变量为蒸发温度、混合工质浓度和汽液分离干度，目标函数为热力学第二定律效率最大；采用遗传算法求解建立的参数优化模型；通过案例分析得到了最优运行参数并与其它形式ORC进行了比较。结果表明：非共沸工质DSORC的第二定律效率比非共沸工质基本ORC（BORC）提高14．1％～17．2％，相比纯工质DSORC第二定律效率提高5．3％-8．7％；DSORC的第二定律热效率随热源的入口温度提高成线性增长。

Double-pressure organic Rankine cycle with a gas-liquid separator( DSORC) is proposed. Parametric optimization of DSORC used binary zeotropic mixtures,basic organic Rankine cycle( BORC) used zeotropic mixtures and DSORC used pure fluids is conducted. The second law efficiency maximization is used as objective function. The optimization variables are mixing ratios of zeotropic mixtures,evaporating temperature and vapor quality in separator.And the optimization model is solved using genetic algorithm. The working fluids under study are: R245 fa,isopentane,hexane,cyclohexane,isohexane,pentane,isobutane,R365 mfc and their binary mixture. The results show that DSORC used zeotropic mixtures has an increase of 14. 1 ~ 17. 2% in second law efficiency compared to BORC used zeotropic mixtures,and an increase of 5. 3 ~ 8. 7% compared to DSORC with pure fluids. The efficiency differences among 8 zeotropic mixtures are less than 3%. The second law efficiency increases linearly with the inlet temperature of heat source.