System Simulation Study on Performance of Non-Supplementary Combustion Liquid Compressed Air Energy Storage System

ObjectivesCompressed air energy storage is a type of energy storage technology with large capacity, long cycle, low cost and high efficiency. Due to the strict requirements of gas storage chambers, gaseous compressed air energy storage cannot be widely promoted and applied in multiple scenarios and on a large scale. Therefore, a non-supplementary combustion liquid compressed air energy storage system was proposed.MethodsA theoretical calculation model was constructed to conduct sensitivity analysis on key parameters such as compressor interstage temperature, number of compressor stages, and turbine inlet temperature within the system. The results were compared with those of a non-supplementary combustion gaseous compressed air energy storage system.ResultsToo low or too high interstage temperature in compressors will restrict the improvement of electric-electric conversion efficiency of the system. The number of compressor stages is positively correlated with compressor power consumption, and negatively correlated with the turbine power generation. Under the same inlet pressure, the higher the inlet air temperature of the turbine is, the larger the power generation is, and the higher the electric-electric conversion efficiency is. Compared with the non-supplementary combustion gaseous energy storage system, the density of non-supplementary combustion liquid energy storage system is increased by 3.7 times, and the volume of the storage chamber is decreased by 9/10.ConclusionsThe non-supplementary combustion liquid compressed air energy storage system effectively solves the problem of gas storage chambers, enabling compressed air energy storage technology to be promoted and applied in multiple scenarios and on a large scale. It is of great significance for deep peak shaving of thermal power units and large-scale energy storage in power grids.