全封闭式涡旋膨胀机在车用有机朗肯循环中的特性研究
Parametric Research on Hermetic Scroll Expander Integrated into Vehicle Organic Rankine Cycle Power Plant System

本文针对中低温余热特性搭建了2 kW目标发电量的小型有机朗肯循环发电系统。实验研究主要针对Hermetic涡旋膨胀机在有机朗肯循环系统中的参数特性表现展开。通过改变膨胀机进出口的状态来探究运行压比和转速对于膨胀机单体及系统性能的影响。性能参数主要包括等熵效率、容积系数、循环热效率及输出电功。结果表明：膨胀机运行压比是影响系统性能的重要参数，输出电功随压比的增大而呈上升趋势，循环热效率及膨胀机的等熵效率随压比变化均存在最优值。考虑内泄漏及摩擦损失等影响，最优运行压比一般应略大于膨胀机设计比。提高膨胀机转速能有效减少内泄漏损失。
A 2-kW small-scale organic Rankine cycle power plant system targeted for medium-low temperature heat sources was established in this study. The experimental research was aimed at investigating how expansion parameters affect the system performance. The performance indicators include isentropic efficiency, filling factor, cycle thermal efficiency, and output electricity. The results indicate that the expander pressure ratio is an important parameter that influences the cycle performance. The output electricity increases with the increase of pressure ratio, while there exists an optimum point for both isentropic efficiency and cycle thermal efficiency. Considering the effect of internal leakage and mechanical friction loss, the optimum operating pressure ratio should be slightly higher than the built-in volume ratio of the expander. It turns out that increasing the expander rotational speed can effectively decrease the internal leakage