Thermodynamics analysis of a combined cooling, heating and power system integrating compressed air energy storage and gas-steam combined cycle

Abstract

The electrical energy storage (EES) with large-scale peak shaving capability is one of the current research hotspots. A novel combined cooling, heating and power (CCHP) system with large-scale peak shaving capability, the compressed air energy storage integrated with gas-steam combined cycle (CAES-GTCC), is proposed in this paper. In the presented system, the methanol absorbs the compression heat through the cracking reaction avoiding the application of a thermal energy storage system in compressed air energy storage (CAES) system, and the generated cracked gas is burned to drive the gas-steam combined cycle (GTCC) for generating electricity. During discharging, part of the gas diverted from the GTCC heats the air that is about to enter the air turbine in CAES to increase the total output power of the system. Moreover, the coupled system could output heating energy and cooling energy at the same time as electricity to realize the energy cascade utilization. By building the thermodynamic model of the system, the thermodynamic performance of the system and the influence of various important parameters on the performance of the system are analyzed. The results show that the output power of the CAES-GTCC during discharging accounted for 157.09% of the total output power during the general period. Furthermore, the energy efficiency of CAES-CTCC can reach 90.81% when the electrical efficiency of the CAES and equivalent electric efficiency of the CAES-GTCC are 48.07% and 74.51%, respectively. Based on the second law of thermodynamics, the exergy efficiency of the CAES-GTCC is expected to be 52.89%.