Optimal design and performance assessment of a proposed constant power operation mode for the constant volume discharging process of advanced adiabatic compressed air energy storage

Abstract

A power operation mode of constant volume discharging process for advanced adiabatic compressed air energy storage (AA-CAES), called compensation mode (C mode), is proposed. The dynamic model of the proposed C mode discharging process is established based on the conservations of mass, momentum, and energy. The reliabilities of compressor, air tank, and air turbine are verified separately. The optimal design is carried out to reduce the power consumed by the compressor. The optimal design pressure ratio and reduced flow rate are 2.48 and 9.292 × 10−5 m·s·K0.5, respectively. This finding proves that the proposed dynamic model obeys the first and second laws of thermodynamics. The exergy distribution of the entire discharging process is studied. Results show that the two largest exergy losses occur in MT and MR. The performance of the proposed C mode is compared with that of the two other operation modes. The proposed C mode enhances the energy storage efficiency of the AA-CAES system by 14.71 %. This study provides a relatively efficient and feasible technical solution for the constant power operation of AA-CAES.