有机朗肯循环-蒸气压缩式热泵联合循环多目标优化及工质匹配

Multi-objective Optimization and Working Fluids Selection for Systems Combined Organic Rankine Cycle With Vapor Compression Heat Pump

本文研究了一种采用有机朗肯循环(ORC)/回热有机朗肯循环(RORC)驱动蒸气压缩式热泵的联合循环系统,根据作者提出的年度现金流量-(?)效率双效图(CE图),采用帕累托最优解集的思想以及多目标遗传算法对系统的热力学和经济性能进行了优化,研究了不同工质组合对联合循环系统性能的影响,获得了最佳的工质组合。结果表明,对于ORC-HP系统,推荐采用R134a-R245fa的工质组合;对于RORC-HP系统,推荐采用R245fa/R1233zd(E)-R245fa的工质组合。同时,研究表明ORC-HP系统的经济性要略优于RORC-HP系统。采用临界温度接近热泵系统冷凝温度的有机物作为热泵系统工质会使得联合循环的热力学性能和经济性均明显降低。

This paper proposed a combined cycle consisting of an organic Rankine cycle(ORC)/regenerative organic Rankine cycle(RORC) and a vapor compression heat pump. Multiobjective optimization method and the Pareto optimal solutions were employed to investigate the thermodynamic and economic performance of the cycle according to the basic theory of annual cash flow-exergy efficiency(CE) diagrams. The impact of different combinations of working fluids(WFs)for ORC and HP on the performance of the combined cycle and the optimal combination of WFs were acquired. The results demonstrate that the optimal WFs combination for ORC-HP system was R134 a-R245 fa, and the best combination for RORC-HP system was R245 fa/R1233 zd(E)-R245 fa. It could also be found that the economic performance of ORC-HP system was superior than that of RORC-HP system. When the critical temperature of the WFs was close to the condensing temperature of the heat pump, the thermodynamic and economic performances of the combined cycle would be weakened.