一种新型压缩空气与抽水复合储能系统的热力学分析

To explore the methods of overcoming the two inherent drawbacks of renewable energy sources (i.e., intermittency and fluctuation), a novel compressed-air based pumped hydro energy storage (CA-PHES) system is proposed using the laws of thermodynamics and the principle of cascade energy utilization in this paper. Firstly, the thermodynamic model of the system was built to evaluate the system's thermodynamic performance. The energy efficiency of this system was investigated with respect to several key parameters, i. e., the discharge time of hydro turbine, the minimum pressure in the air storage cavern, the efficiency of each equipment and the distribution of pressure ratio in compressor and turbine. The result indicated that the system's energy efficiency increases with the increasing of the minimum air pressure in the air storage cavern. While with the increasing of the discharge time of hydro turbine, the energy efficiency reaches its maximum value at 1.5 hour and then decreases. Furthermore, the most effective way to improve the energy efficiency is to increase the isentropic efficiency of turbine. By employing an evolutionary multi-objective algorithm, the energy efficiency could reach 71.82%. The results could provide valuable theoretical basis for the further engineering application of this energy storage system.