Investigation of operation strategy of combined cooling, heating and power(CCHP) system based on advanced adiabatic compressed air energy storage

Abstract

Combined cooling, heating and power(CCHP) system can meet the diversified demand of users. To investigate the performance of CCHP system based on advanced adiabatic compressed air energy storage(AA-CAES) under different operation strategies, four operation scenarios of compressor-expander, which are respectively constant-constant, constant-sliding, sliding-constant, and sliding-sliding, are proposed in this paper. By employing the numerical simulation method, system performance of four scenarios is compared via energy analysis and exergy analysis. Meanwhile, a parametric analysis is conducted to evaluate the influence of key parameters on system performance. The results show that cycle efficiency, thermal efficiency and exergy efficiency of sliding-sliding scenario are all the highest, 48.31%, 91.04% and 56.48%, respectively. And exergy density of constant-sliding scenario is the biggest, 7.69 × 106 J m−3, when design parameters of system are the same. In addition, second heat exchanger makes the largest contribution to the overall exergy destruction of system. For the four operation scenarios, with heat exchanger effectiveness increasing, cycle efficiencies exist optimal values, whereas thermal efficiencies, exergy efficiencies and exergy densities gradually augment. The influence of ambient temperature on different performance indexes is different. The increase of ambient pressure has negative effect on exergy densities, but it has positive effect on other performance indexes.