冷却水流量对ORC系统性能影响的实验研究

采用自主研发的单螺杆膨胀机作为机械动力，实验研究了冷却水流量对ORC余热发电测试系统及单螺杆膨胀机性能的影响。实验结果表明：当冷却水流量从8 m³·h^-1升至19 m³·h^-1时，单螺杆膨胀机输出功和轴效率分别从4.31 kW、36.38%增至5.15 kW、41.1%，分别增加了19.5%、13%。针对本实验系统，在考虑润滑油泵、工质泵、冷却水泵和冷却塔风扇等所有系统辅机功耗之后，当冷却水流量为12 m³·h^-1时，系统净输出功和系统净效率达到最大值，分别为2.44 kW和2.47%。通过研究冷却水流量对ORC系统性能的影响，为ORC冷却系统的设计和优化系统性能提供重要的实验依据。

Effect of cooling water flow rate on power generation of organic Rankine cycle system

A single screw expander was used as the power generation machine. The effect of cooling water flow rate on the performance of the ORC system and the single screw expander is studied to generate power from low-grade waste heat. The results show that when the cooling water flow rate from 8 m³·h^-1 to 19 m³·h^-1, the output power and shaft efficiency of the single screw expander increase by 19.5% and 13% from 4.31 kW and 36.38% to 5.15 kW and 41.1%, respectively. In this experimental system, when the cooling water flow is 12 m³·h^-1 and the power consumed by the circulation pump, the lubricating oil pump, the water pump and the cooling tower fan were all taken into account, the maximum value of the system net output power and the system net efficiency would be 2.44 kW and 2.47% respectively. Therefore, the cooling water flow rate significantly affected the performance of an ORC system with low-grade waste heat, which could serve as important reference for designing cooling source system and optimizing ORC system performance.