Experimental investigation on a one-rotor two-stage desiccant cooling/heating system driven by solar air collectors

A solar driven one-rotor two-stage desiccant co[oling/heating system is experimentally investigated. It consists primarily of a 5 kW desiccant cooling system and 15 m2 of solar air collectors. The desiccant cooling/heating system uses solar thermal energy to regenerate desiccant wheel in summer, and to produce hot air for space heating in winter. In summer, the outlet temperature of solar air collectors is about 60–100 °C. For the solar driven one-rotor two-stage desiccant cooling system, the moisture removal can reach 8–9 g/kg and supply air condition is about 22 °C and 60% RH. Experimental results indicated that the average thermal COP in cooling cycle is 0.95 in hot and humid climate conditions. The solar COP of system is about 0.45 when thermal efficiency of collector is 50%. This suggested that the system could convert more than 40% of the received solar radiant intensity to cooling power in sunny days. In addition, the effect of regeneration temperature on the system performance is studied. It was found that average of temperature difference between ambient and room can reach 13 °C for space heating in winter. Coupled with desiccant cooling system, solar air collectors can realize year-round running.