含余热回收的超临界压缩二氧化碳储能系统热力学特性研究

Compressed carbon dioxide energy storage system has attracted wide attention due to its advantages of high round-trip efficiency and high energy storage density, and is considered to be a promising energy storage technology. In this paper, we propose a supercritical compressed carbon dioxide energy storage system with turbine waste heat recovery and establish a thermodynamic model of the system. In accordance with the principles of thermodynamics, a critical parameter analysis and a thermodynamic analysis of the system are conducted. In order to achieve the optimal round-trip efficiency and energy storage density of the system, genetic algorithms are employed to conduct both single-objective and multi-objective optimization of the four key system parameters. This approach enables the identification of the optimal system performance. The results demonstrate that, under the specified parameters, the system exhibits a round-trip efficiency of 37.21%, a power efficiency of 33.44%, and an energy storage density of 8.31 kW·h·m^-3. Among the four key parameters, the low-pressure tank pressure and the turbine inlet temperature have a more obvious impact on the system performance. Single-objective optimization yielded an optimal round-trip efficiency of 52.69% and an optimal energy storage density of 17.16 kW·h·m^-3. Multi-objective optimization yielded an optimal solution with favorable overall performance, with a round-trip efficiency of 46.88% and an energy storage density of 13.97