热泵储电系统的热力学分析

Thermodynamic analysis for heat pump electricity storage system

热泵储电技术可由多种热力学循环类型和储热/储冷类型的组合实现。为了研究热泵储电系统损失产生的机制及各类损失因素对循环效率的影响,本文在传统循环计算的基础上进行了热力学分析和参数敏感性研究。对热泵储电系统储能和释能过程进行了热力学建模和分析,通过控制变量法分析了系统参数,包括压缩/膨胀过程效率、换热端差、阻力、储热/储冷效率等对热泵储电系统性能的影响,得到了各设计参数对系统循环效率影响程度的相对值,即敏感系数。最后提出,通过优化影响程度最高的关键设计参数,如提高压缩/膨胀过程效率、降低机械损失和换热端差等,可实现热泵储电系统性能的提升。研究结果可为热泵储电系统的优化设计提供参考。

Pumped thermal electricity storage(PTES)technology can make use of different types of thermodynamic cycles and thermal storages.To study the loss-generating mechanism and the effects of various losses on cycle efficiency of the PTES,thermodynamic analysis is presented based on the conventional cycle calculations coupled with parameter sensitivity analysis of influence factors.The thermodynamic models of the PTES charge/discharge process are established,and the thermodynamic cycle parameter sensitivity is analyzed by variable control,focusing on various losses and their effects on cycle efficiency of the PTES.The sensitivity coefficients,namely the affecting degree of various parameters on the cycle efficiency,are obtained.The results show that,through optimizing the key design parameters that affecting the cycle efficiency the most,such as enhancing the compression and expansion efficiencies,and reducing the mechanical losses and heat transfer temperature difference,can improve the PTES system's performance.The results can provide theoretical reference for PTES system optimum design.