工质的特性是影响ORC(有机朗肯循环）系统性能的重要因素之一。建立了65~100 ℃低温地热水有机朗肯循环发电系统数学模型，将R245fa分别与R601a和R227ea以不同比例混合作为ORC系统的工质，比较了非共沸混合物和纯物质两类工质对ORC系统循环净功、热效率和火用效率的影响。研究结果表明：无论是纯工质还是非共沸工质，系统的循环净功、热效率和火用效率都随着热源温度的升高而增大。工质在相变过程中是否存在温度滑移，是影响ORC系统性能的重要因素之一。在65~100 ℃的热源条件下，综合考虑3个评价指标，当R245fa配比为0.1~0.7时，R245fa/R601a混合物的循环净功、热效率和火用效率分别提升0.012~2.48 kW、0.005%~1.15%和0.08%~10.7%；当R245fa配比为0.5~0.9时，R245fa/R227ea混合物的循环净功、热效率和火用效率分别提升0.049~4.25 kW、0.057%~1.75%和0.21%~16.1%。

Characteristic of working fluids is one of the most important factors that affect the Organic Rankine Cyclesystem(ORC). A mathematical model for low temperature geothermal water Organic Rankine Cycle power generation system at 65 ℃~100 ℃ was established. R245fa was mixed respectively with R601a and R227ea in different proportions as working fluids in ORC system. The effects of zeotropic mixtures and pure substance on cycle net work, thermal efficiency and exergy efficiency in ORC system were compared. The results showed that for both pure and zeotropic working fluids, the cycle net work, thermal efficiency and exergy efficiency increase with the heat source temperature. During the phase transition process, whether or not there is temperature slip is one of the important factors that affect the performance of ORC system. With three evaluation indexes considered, for the heat source condition of 65 ℃~100 ℃ and the R245fa ratio of 0.1~0.7, the cycle network, thermal efficiency and exergy efficiency of R245fa/R601a increase by 0.012 kW~2.48 kW, 0.005%~1.15% and 0.08%~10.7%, respectively. For the R245fa ratio of 0.5~0.9, the cycle network, thermal efficiency and exergy efficiency of R245fa/R227ea increase by 0.049 kW~4.25 kW, 0.057%~1.75% and 0.21%~16.1%, respectively

TK47

国家自然科学基金（51574179）