Study on Turbo-generator Set Based on Compressed Air Energy Storage

Compressed air energy storage (CAES) is a novel energy storage technology which can utilize intermittent renewable energy or nightly off-peak electric power. By the CAES technology, electric power can be stored in the form of compressed air and the compressed air will be released to drive turbo-generator set for generation when needed. In this paper, the principle of turbo-generator set was introduced based on the 500 KW CAES demonstration project. Also, a novel multi-stage coaxial air turbine, configuration of the number of stages, input pressure and the diameter of impellers were all analyzed. The results show that the optimum parameter is three stages with an input pressure of 2.5 MPa. Moreover, the control valve, reducer and generator were designed and configured. The theoretical efficiency of this generator set was calculated to be 77.5 %. The concept of COP was introduced here to assess the application prospects and economic benefits.