基于有机朗肯循环的低温太阳能发电系统工质的选择

摘要

Organic Rankine cycle (ORC) system uses organic fluids as working fluids to promote the work of the turbine.It performs better in recovering low enthalpy containing heat sources.The thermodynamic properties of working fluid have a significant effect on performance of solar organic Rankine cycle (ORC).According to the collector temperature of 120℃,and the evaporation temperature of 100℃,this article took R245fa,R123,R236fa,R113,R245ca,R600 and R601 as candidate working fluids,during which the evaporation temperature,thermal efficiency,exergy efficiency and total irreversible loss were respectively calculated and compared by using Matlab and PERPROP softwares.The results show:R123 performs relatively high thermal and exergy efficiency and produces relatively low total irreversible loss in low temperature solar ORC system,which is recommended as a desirable working fluid for the ORC system of evaporation temperature below 100℃.%有机朗肯循环系统利用低沸点的有机物作为工质推动透平做功,在低品位热能的利用方面更有优势.循环工质的选择是影响有机朗肯循环系统性能的关键因素之一.本文针对集热温度120℃,蒸发温度在100℃以下的低温太阳能有机朗肯循环系统进行了工质的研究分析,选择R245fa,R123,R236fa,R113,R245ca,R600,R601 7种工质,以工质的热效率、炯效率及系统不可逆损失为评价指标,利用Matlab和PERPROP软件对候选工质的各热力参数进行了比较.结果表明:低温太阳能有机朗肯循环发电系统的选用R123作为循环工质时具有较高的热效率和炯效率,且系统总不可逆损失较低,适合作为蒸发温度100℃以下的低温有机朗肯循环系统的循环工质.