有机朗肯循环系统孤网运行的实验研究

Experimental study of an integrated organic Rankine cycle system under isolated network operating condition

针对孤网环境下有机郎肯(ORC)系统的实际应用,以R245fa为工质,采用单螺杆膨胀机与同步发电机同轴联动,设计集成了一台10k W级的小型ORC机组,并以10.5k W的卤素灯阵作为孤网负载,就地消耗机组输出的电能。实验中在115℃热源条件下通过调整负载容量改变ORC系统的运行工况,对不同负载与膨胀机转速下ORC系统性能进行实验研究。实验数据表明:单螺杆膨胀机的性能较为优良,其等熵效率最大值为84.1%,随负载及膨胀机转速的增加而减小。工质泵的实际运行效率为8.31%~19.10%,其等熵效率随负载及转速增大而变大,最大值为73.97%。工质泵的机械效率较低,仅为19.22%~36.82%,与负载及膨胀机转速之间没有明显关系,较低的机械效率是工质泵实际运行效率偏低的主要原因。机组电功随负载及膨胀机转速的增加而增大,最大发电量与发电效率分别为5.86k W与7.38%。

The test results of a10kW integrated organic Rankine cycle(ORC)system with R245fa as the working fluid under isolated network operating condition were presented in this paper.A single screw expander was integrated in the system to drive the synchronous generator to generate electric power.The10.5kW halogen lamp array was used as the load to consume the generated electric power.Two independent parameters,the load capacity and the expander speed,were varied during the test.The ORC system characteristics were analyzed at the heat source temperature of115℃.The experimental data showed that the single screw expander performed very well.The maximum expander isentropic efficiency was84.1%,which decreased with increase of load and expander speed.The maximum isentropic efficiency of working fluid pump was73.97%,which increased with the increase of load and expander speed.The mechanical efficiency of the working fluid pump was only19.22%-36.82%,and had no obvious relationship with the load and the expander speed.The generated electric power increased with the increase of load and expander speed.The maximum generated electric power and the electrical efficiency were5.86kW and7.38%,respectively.