含相变储热的喷射式热泵系统模拟与优化

Simulation and Optimization of Injection Heat Pump System with Phase Change Heat Storage

为了实现热电解耦,有效提高可再生能源利用率,将相变储热技术应用于热泵系统中,构建含相变储热罐的跨临界CO_(2)喷射式热泵系统。首先,建立储热装置的数学模型,采用Modelica非因果建模语言在Dymola平台对系统储热过程进行模拟,获得相变储热罐的温度分布、瞬时储热量、系统能效比等储热特性。同时对比了常规储热水箱、相变储热罐与相变-水多级储热罐的理想储热量、设备体积、储热性能等,详细分析相变储热热泵系统的优势,为促进其实际应用提供参考。此外,提出基于模型的单目标与多目标优化策略,采用遗传算法对系统的性能进行优化,得到最优设计参数和运行参数,与优化前相比储热过程的系统总能效比提高了28.73%,有利于系统的高效运行,为改进和优化系统性能提供了依据。

In order to realize thermoelectric decoupling and effectively improve the utilization rate of renewable energy,phase change heat storage technology was applied to the heat pump system,and a transcritical CO_(2) injection heat pump system with phase change heat storage tank was constructed.Firstly,the mathematical model of the thermal storage device was established,and the thermal storage process of the system was simulated on Dymola platform with Modelica non-causal modeling language,and the thermal storage characteristics such as temperature distribution,instantaneous heat storage capacity and coefficient of performance(COP)of the system were obtained.At the same time,the ideal heat storage capacity,equipment volume and heat storage performance of conventional heat storage tank,phase change material(PCM)heat storage tank and PCM-water heat storage tank were compared,and the advantages of PCM heat storage pump system were analyzed in detail.In addition,a model-based single-objective and multi-objective optimization strategy was proposed.The performance of the system was optimized by genetic algorithm,and the optimal design parameters and operation parameters were obtained.Compared with before optimization,the system COP of the heat storage process was improved by 28.73%,it is beneficial to the efficient operation of the system and provides the basis for improving and optimizing the performance of the system.