Multi-objective optimization of a combined cooling, heating, and power system with subcooled compressed air energy storage considering off-design characteristics

In this work, the performance of a combined cooling, heating, and power system is studied under dynamic operation conditions. The hybrid system consists of a wind farm and a subcooled compressed air energy storage system, providing energy for an integrated energy network including established heating, cooling, and electricity grids. For the presented system, real wind fluctuation data and the off-design performance characteristics of each component are considered. The efficiency of the integrated cooling, heating and power system and the cost of the system are taken into account as the objectives of the problem to optimize. Then, a bi-level differential evolution algorithm is proposed to handle the multi-objective optimization of the system. Different solutions are carried out and compared to investigate the trigeneration of the system under various energy demand conditions. The results show that the off-design characteristics have a significant side-effect on the trigeneration performance of the system. The storage system has more obvious advantages in the transition season, as the states of charge of the system are 82%, 84% and 92% in winter, summer and transition seasons, respectively. The application of the system can effectively avoid the negative effect of the off-design characteristics of equipment and has great potential for energy supply in combined cooling, heating, and power systems.