In this study, thermodynamic analysis was performed on basic and recuperative transcritical organic Rankine cycles by using five pure and six mixed fluids. The effects of evaporation parameters on the first- and second-law efficiencies (η_I and η_II) as well as power output were investigated. The results indicate that a recuperator had a positive effect on the η_I and η_II and negative effects on the specific power. The total irreversibility of the system was improved by the recuperator. However, the total irreversibility considerably increased with an increase in the expander inlet temperature (T_exp,in) due to the significant increase in irreversibility in the condenser, particularly for working fluids with low critical temperatures, namely R134a, R1234yf and R290, and low proportions of R245fa and R600a in mixed fluids. For both the pure and mixed fluids, the specific power linearly increased with an increase in the expander inlet pressure (P_exp,in) and T_exp,in. However, with an increase in P_exp,in, the η_I and η_II first increased and then decreased. Finally, for η_I and η_II, the effect of the recuperator increased with an increase in T_exp,in even though the recuperator had a relatively small effect on the working fluids with high critical temperature, especially when P_exp,in was high.

中文翻译：

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蒸发参数对二元混合流体换热跨临界有机Rankine循环的影响。

在这项研究中，通过使用五种纯净流体和六种混合流体对基本和同流换热的有机朗肯循环进行了热力学分析。的蒸发参数对第一级和第二定律效率的影响（η_我和η _II），以及功率输出进行了研究。结果表明，换热器已经在积极的作用η_我和η _II和比功率的负面影响。换热器改善了系统的总不可逆性。但是，总不可逆性随着膨胀机入口温度（T _exp，in）是由于冷凝器中不可逆性的显着增加，特别是对于临界温度低的工作流体，即R134a，R1234yf和R290，以及混合流体中的低比例的R245fa和R600a。对于纯流体和混合流体，比功率都随膨胀机入口压力（P _exp，in）和T _exp，in的增加而线性增加。然而，随着在P _EXP，在中，η_我和η _II先增大后减小。最后，对于η_我和η _II，同流换热器的效果的增加增加Ť_EXP，在即使换热器对具有高临界温度的工作流体的影响相对较小，特别是当P _EXP，在为高。