匹配新能源电能并网的压缩空气储能站性能研究

Performance Analysis of Compressed Air Energy Storage System for Grid-connection of Renewable Power

[目的]压缩空气储能系统在电能释放环节依托节流降压阀进行调压的方法,存在较大的空气压力能损失,降低了压缩空气储能系统的能量转换效率。[方法]引入喷射调压理论,通过高压流体对低压流体的自动卷吸作用获得中压流体的方法来完成调压过程,减少由节流降压阀引起的压力能损失。在研究过程中,分别构建了融合"节流阀调压"、"固定式匹配器调压"以及"可调式匹配器调压"三种不同调压方式的压缩空气储能系统并进行了性能比较分析。[结果]研究结果表明:"固定式匹配器调压"方法与"可调式匹配器调压"方法通过压力能回收,使得首台膨胀机可做功气流总量分别增加了2%与4.1%,储能系统的能量转换效率也由节流阀调压储能系统的59.26%分别提升至59.60%与59.97%。[结论]性能优化后的压缩空气储能系统能够服务于新能源电能并网需求,通过储能站与新能源电能发电站形成联合体的方式,促进新能源电能的消纳。

[Introduction]There is an obvious pressure energy loss in the electricity output process of Compressed Air Energy Storage（ CAES） system,which is caused by pressure regulating valves. The existing of pressure energy loss results in an efficiency drop of CAES system. [Method] In this manuscript,the ejector technology was introduced into CAES systems to finish the air flow pressure regulating process. The target air flow with middle pressure parameter could be obtained by high pressure air flowejecting low pressure air flow in ejectors. It causes less pressure energy loss than pressure regulating valves. In this investigation,we built and analyzed the performance of three CAES systems with three different pressure regulating methods,including ＂pressure regulating process only through valves＂,＂ejectors with fixed throat area＂and＂ejectors with adjustable throat area＂. [Result] The results show that ejector technology can recover the pressure energy loss by increasing working air flow amount. There is about 2% percent additional air flow under ejector with fixed throat area. There is also about 4. 1% percent additional air flow under ejector with adjustable throat area. The energy conversion efficiency of CAES system with pressure regulating valves is 59. 26%,and those of CAES systems with fixed ejector and adjustable ejector increase to 59. 60% and 59. 97%,respectively. [Conclusion] The optimized CAES systems can be combined with renewable resource power plants to form united-power plants,which has positive effect in grid-connection of renew-able power.