Thermodynamic Analysis of Variable-stage Compression and Variable-stage Expansion Advanced Adiabatic Compressed Air Energy Storage System

摘要

In this research, a new type of variable-stage compression and variable-stage expansion advanced adiabatic compressed air energy storage system is proposed. The compressors and turbines enable to change the running stages by adding bypasses and valves. In order to study the performance of the system, three different operation modes, conventional mode, rated pressure ratio mode, and variable pressure ratio mode, are presented. Thermodynamic performance of different modes is compared and analyzed by means of numerical simulation. To further enhance the system performance, the influence of the operating pressure of the air storage tank and the number of compressor and turbine stages are studied. The research results show that the new system can effectively improve the energy storage density. When the stages of compressor and turbine is greater than 3, the charging and discharging efficiency of the variable pressure ratio mode is the highest. The research results provide an effective way to improve the performance of advanced adiabatic compressed air energy storage system.