为解决液态二氧化碳储能系统(LCES)余热难以充分利用的问题，提出一种回收余热的LCES系统(WHR-LCES)，进行热力学分析和经济性评估，对比研究WHR-LCES系统与LCES系统性能差异。结果表明：在相同初始设计参数下，WHR-LCES系统循环效率和储能密度分别为57.62%和18.72 kW·h·m-3，较LCES系统分别提升1.87%和9.92%，平准化度电成本为0.1565美元·(kW·h)-1，较LCES系统降低3.58%；?分析结果表明，压缩、透平、蓄冷和中间换热过程是系统主要?损环节；对于WHR-LCES系统，降低节流阀压降、液泵增压量、透平机出口压力可提高系统性能，合理的压缩机出口压力和间冷器热流体出口温度可保障系统高性能运行。

To address the challenge of inefficient waste heat utilization in liquid carbon dioxide energy storage (LCES) systems, a novel system integrating waste heat recovery (WHR-LCES) is proposed. A thermodynamic analysis and economic assessment are conducted, with a comparative study performed to evaluate the performance differences between the WHR-LCES and the conventional LCES system. The results demonstrate that under identical design parameters, the WHR-LCES system achieves a round-trip efficiency of 57.62% and an energy storage density of 18.72 kW·h·m?3, representing improvements of 1.87% and 9.92%, respectively, over the system. Additionally, the levelized cost of electricity is USD 0.1565 per kW·h, which is 3.58% lower than that of the LCES. Exergy analysis indicates that compression, expansion, cold storage, and intermediate heat exchange processes are the primary sources of exergy destruction. For the WHR-LCES system, performance can be enhanced by reducing the pressure drop across the throttle valve, the pressure increase by the liquid pump, and the outlet pressure of the turbine, while maintaining appropriate compressor outlet pressure and intercooler hot-fluid outlet temperature is essential for ensuring high performance system operation.

TK02

甘肃省联合科研基金重大项目(23JRRA1549)