PERFORMANCE STUDY OF CASCADED LATENT HEAT STORAGE COUPLED WITH HEAT PUMP
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%.