Keeping output stable is necessary for solar organic rankine cycle (SORC) considering variable solar irradiation conditions. In this study, zeotropic mixtures are introduced into SORC with stable output. Evaporation pressure and turbine inlet temperature are optimized with the overall system efficiency as optimization objective. Comparisons are drawn between the basic SORC and regenerative SORC. The influences of zeotropic mixture composition on the overall system efficiency, ORC efficiency, heat source outlet temperature, mass flow rate of heat source and working fluids and temperature rise of internal heat exchanger (IHE) are analyzed. The results show that zeotropic mixtures can slightly increase the overall system efficiency of the basic SORC system compared with the optimal pure working fluid system, but for the regenerative SORC system, the optimal overall system efficiency is higher when pure cyclohexane is used. When cyclopentane mole fraction is 0.4, the overall system efficiency of the basic SORC system reaches maximal value of 16.08%, which is 0.12% higher than for the optimal pure working fluids system, relatively. Under the optimum conditions, the optimal overall system efficiency of the regenerative SORC system is 52.11% higher than that of the basic SORC system.

中文翻译：

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环戊烷/环己烷混合物稳定输出的太阳能有机朗肯循环的性能分析▴

考虑到可变的太阳辐照条件，保持输出稳定对于太阳有机朗肯循环（SORC）是必要的。在这项研究中，将共沸混合物以稳定的产量引入SORC。以整体系统效率为优化目标来优化蒸发压力和涡轮进口温度。基本SORC和再生SORC进行了比较。分析了共沸混合物组成对整体系统效率，ORC效率，热源出口温度，热源和工作流体的质量流量以及内部热交换器（IHE）的温升的影响。结果表明，与最佳纯净工作流体系统相比，共沸混合物可以稍微提高基本SORC系统的整体系统效率，但对于再生SORC系统，当使用纯环己烷时，最佳的整体系统效率更高。当环戊烷摩尔分数为0.4时，基本SORC系统的整体系统效率达到最大值16.80％，相对于最佳的纯工作流体系统而言，它高出0.12％。在最佳条件下，再生式SORC系统的最佳整体系统效率比基本SORC系统高52.11％。