Impact of gas solubility on energy efficiency in liquid piston compressed air storage: Modeling and analysis

The integration of liquid pistons into compressed air energy storage systems for achieving isothermal or quasi-isothermal compression has emerged as a significant research focus. However, during the compression process, liquid pistons dissolve considerable amounts of gas, adversely affecting system efficiency and stability. To explore the impact of gas dissolution on liquid piston compressed air energy storage systems, this paper constructs an air dissolution model based on chemical potential equilibrium theory. This model is subsequently coupled with the liquid piston compressed air system model, unveiling the patterns of air dissolution within the system. Additionally, the paper examines the effects of initial temperature and pressure on air dissolution. The findings indicate that in a closed variable space, the amount of gas dissolved increases with rising pressure and decreases with higher temperatures. During compression, air dissolution reduces system efficiency from 89.25% to 81.68%. While the initial temperature has minimal impact on air dissolution, the initial pressure significantly influences gas dissolution. With an initial pressure of 2 MPa and a compression ratio of 7, 30.42% of the air dissolves into the liquid piston.