Dynamic simulation of a cooling, heating and power system based on adiabatic compressed air energy storage

Abstract

The adiabatic compressed air energy storage (A-CAES) system stores energy during periods of low energy demand (off-peak) and releases it to meet the higher demand in peak load periods. In this work, a modified A-CAES system with phase change materials and water thermal energy storage was proposed to achieve less energy loss. For the system, an apparent characteristic is cooling, heating, and power output simultaneously, and the most outstanding advantage is the utilization of thermal energy from ambient atmospheric air for the expansion process. By constructing the dynamic model of the system, performance of the system and each component are investigated in detail. The results show that the phase change thermal energy storage dynamic behavior has an important effect on stable output power: extending phase change time during discharge may steady power output. Under stable operation condition (after 3 cycles), the system can generate 308.27 kWh electricity, 50.98 kWh cooling and 185.25 kWh heat with a round-trip efficiency of 96.56% and an electricity efficiency of 61.15%. In the system, the air storage tank is the major contributor of energy loss, accounting for 86.67% of total energy loss. To the authors’ best knowledge, the present study is the first of this kind for such a modified A-CAES system with phase change and non-phase change thermal energy storage.