Review on Ejector-Integrated Compressed Gas Energy Storage System

Abstract Compressed gas energy storage is an important technical approach to addressing the fluctuation problem of renewable energy grid connection. However, in practical applications, it still faces challenges such as low utilization rate of waste heat and large throttling losses. The ejector can effectively recover expansion work, reduce throttling losses, and lower the pressure of the cushion gas, and can be integrated with the compressed gas energy storage system in multiple efficient ways. This paper systematically reviews the basic principles and development status of compressed gas energy storage technology, and focuses on analyzing the integration methods and application effects of ejector in different types of energy storage systems. Research indicates that the introduction of an ejector can enhance the system's cycle efficiency by 2% to 4.38%, resulting in an approximate 21% increase in the profit of system. Additionally, incorporating an ejector can improve the energy storage density of the gas storage facility and enhance the system's cooling capacity. Finally, based on the current situation, judgments are made on the existing problems and future development directions.