鉴于水工质朗肯循环(H2O-RC)应用于中高温(500-700℃)烟气余热动力回收过程中存在的不足,提出2种复合循环:CO2超临界循环(CO2-SC)/有机工质跨临界循环(OTC),和空气布雷顿循环(Air-BC)/有机工质跨临界循环(OTC).开展了以循环净输出功率为目标函数,以顶循环膨胀初压、终压和底循环膨胀初压、初温为优化变量的优化对比研究,得到了各循环参数对复合循环热力学性能的影响规律.结果表明:当烟气温度为500℃和600℃时,CO2-SC/OTC热力学性能最优;当烟气温度为700℃时,H2 O-RC热力学性能反超复合循环,存在最大的净输出功率;基于500-700℃烟气余热动力利用,CO2-SC/OTC热力学性能整体上优于Air-BC/OTC.%Taking into account the shorting of the Rankine cycle with water as working fluid,two kinds of compound cycles are proposed:CO2 supercritical cycle (CO2-SC) / Organic working fluid transcritical cycle (OTC),and the air brayton cycle (Air-BC) / organic working fluid transcritical cycle (OTC).The net output power is used as the objective function to optimize the thermodynamic parameters of the composite cycle,and the influence of cycle parameters on the thermodynamic performance of the compound cycle is obtained.The results show that the CO2-SC/ OTC has the best thermodynamic performance when the flue gas temperature is 500 ℃ and 600 ℃.When the flue gas temperature is 700 ℃,the net output of H2O-RC is higher than that of two compound cycles.Based on the utilization of flue gas in the range of 500-700 ℃,the thermodynamic performance of CO2-SC/OTC is better than Air-BC/OTC.
展开▼
