级联型潜热储存耦合热泵系统性能研究

PERFORMANCE STUDY OF CASCADED LATENT HEAT STORAGE COUPLED WITH HEAT PUMP

为提高太阳能利用率和热泵热力学性能,将真空管集热器、热泵和填充床等结合,提出一种级联型潜热储存耦合热泵系统用于建筑供热。针对太阳能集热及室外温度等条件,将太阳能蓄热和室外空气作为热泵的热源进行系统集成设计。在FLUENT和EES中分别建立填充床和热泵的热力学模型,并分析填充床的换热流体流量、放热温度和用户回水温度对系统热力性能的影响。结果表明,填充床流体流量从0.05 kg/s增至0.07 kg/s时,热泵系统整体平均性能指数下降0.16;填充床作为热源的放热温度升高20℃时,填充床供热增加74269 kJ,有效放热率下降21.9%;当用户回水温度升高10℃时,热泵系统整体平均性能指数下降0.19,有效放热率下降16.2%。

To enhance the utilization of solar energy and optimize the thermodynamic performance of heat pumps,a cascaded latent heat storage coupled heat pump system is proposed for building heating.The system integrates a vacuum tube collector,a heat pump,and a packed-bed and is designed to collect solar energy while taking into account atmospheric temperature,using outdoor air as the heat source for the heat pump.In this study,thermodynamic models of the packed-bed and heat pump components are developed using the FLUENT and EES software respectively.The thermal performance of the system is analyzed with regards to the flow rate,exothermic temperature of the packed-bed,and user return water temperature.Results indicate that increasing the flow rate of the packed-bed from 0.05 kg/s to 0.07 kg/s results in a 0.16 decrease in the overall average performance of the heat pump.When the exothermic source temperature of the packed-bed is raised by 20℃,the heat supply of the packed bed increases by 74269 kJ,but the effective heat release rate decreases by 21.9%.Furthermore,when the user return water temperature is increased by 10℃,the overall average performance of the heat pump decreases by 0.19,and the effective heat release rate declines by 16.2%.