ORC-CHP (combined heat and power based on organic Rankine cycle) systems have been widely adopted to recover low-grade heat. Economy, one of the advantages of ORC-CHP system, is optimized and compared in this paper. Three ORC-CHP systems are simulated and compared, including SS (serial system), the CS (the condensation system) and SS/CS (serial/condensation system). Energy-exergy-economic (3E) models for these cycles are developed, by using the genetic algorithm, the system performances are optimized with respect to the maximum profit ratio of investment (PRI). The result shows that the SS/CS has the highest PRI value under the considered working conditions. According to the results of economic analysis, the cost of the heat exchangers occupies the largest share in the three systems, all above 70%. When operated under optimal working conditions, most of the energy in the heat source is used to heat return water, leading to all three systems showing low electrical efficiency (less than 0.7%) and high thermal efficiency (more than 92%). Exergy analysis shows that most of the exergy destruction to the SS and the SS/CS occurs in hot water heaters, while for CS, it mainly occurs in the evaporator (67.48%) and then the condenser (31.35%).

ORC-CHP（基于有机朗肯循环的热电联产）系统已被广泛用于回收低品位热量。经济性是ORC-CHP系统的优势之一，本文对其进行了优化和比较。模拟和比较了三种 ORC-CHP 系统，包括 SS（串联系统）、CS（冷凝系统）和 SS/CS（串联/冷凝系统）。开发了这些循环的能量-火用-经济（3E）模型，通过使用遗传算法，系统性能相对于投资的最大利润率（PRI）进行了优化。结果表明，SS/CS 在考虑的工作条件下具有最高的 PRI 值。根据经济分析结果，换热器成本在三个系统中所占份额最大，均在70%以上。在最佳工作条件下运行时，热源中的大部分能量用于加热回水，导致所有三个系统都表现出低电效率（小于0.7%）和高热效率（大于92%）。火用分析表明，对SS和SS/CS的火用破坏大部分发生在热水器中，而对于CS，主要发生在蒸发器（67.48%）和冷凝器（31.35%）。