非共沸混合物有机朗肯循环烟气余热利用的模拟与优化

Simulation and optimization of flue gas waste heat utilization by organic Rankine cycle with zeotropic mixtures

利用Aspen HYSYS软件模拟非共沸混合物有机朗肯循环回收利用压气站烟气余热;综合考虑循环工质环保性、安全性、临界温度与热源温度的匹配性等性能,选取苯、甲苯与R141b和R123分别混合作为循环工质;提出以一段时间内的平均净输出功为优化目标,对比苯/R141b、苯/R123、甲苯/R141b和甲苯/R123作为循环工质的循环性能,分析蒸发压力、冷凝压力、非共沸混合工质组分及其物质的量比等关键因素对系统平均净输出功的影响,并确定最佳工况。研究结果表明:当冷凝压力为100 kPa,蒸发压力为3000 kPa,混合工质为苯/R141b(苯与R141b物质的量比为0.4/0.6)时,系统平均净输出功最大,比苯作为循环工质的平均净输出功增大4.7%。

Aspen HYSYS software was used to simulate the organic Rankine cycle using zeotropic mixtures for the recovery and utilization of waste heat from compressor station flue gas.Considering the environmental protection,safety,matching of critical temperature and heat source temperature,benzene,toluene,R141b and R123 were selected as the circulating working fluids.The average net output work over a period of time was proposed as the optimization objective.The cycle performance of benzene/R141b,benzene/R123,toluene/R141b and toluene/R123 as circulating working fluids were compared,and the influences of key factors were analyzed such as evaporation pressure,condensation pressure,the components of zeotropic mixtures and their molar ratios to the average net output work of the system.The best working condition was determined.The results show that when the condensing pressure is 100 kPa,the evaporation pressure is 3000 kPa,and when the mixed working medium is benzene/R141b(molar ratio of benzene and R141b with 0.4/0.6),the average net output work of the system is the largest,which is 4.7%higher than that of benzene as the circulating working fluid.