Theoretical Analysis and Case Study on Solar Driven Two-stage Rotary Desiccant Cooling System Combined with Geothermal Heat Pump

In this paper, a solar hybrid desiccant air conditioning system, which combines the technologies of two-stage desiccant cooling system and geothermal heat pump together, has been configured and theoretically analyzed. The hybrid system mainly includes a two-stage desiccant cooling system with design cooling capacity of 80 kW, a geothermal heat pump for fresh air handling with 75 kW in nominal cooling capacity, a geothermal heat pump for capillary radiation terminal with cooling capacity of 244 kW, an evacuated tubular solar collector array of 530 m2, a hot water storage tank and a cooling tower. Performance model of the system has been created in TRNSYS simulation studio. The aim of this paper is to evaluate the performance of the solar hybrid air conditioning system, thereby providing useful data for practical application in the demonstration project. Simulation results show that, under typical weather condition, the solar driven desiccant cooling unit can achieve an average cooling capacity of 70 kW, which contributes 31.4% of the cooling capacity provided by the hybrid system. Corresponding average thermal COP is about0.83 under Shanghai weather conditions.