An energy flow analysis of a solar desiccant cooling equipped with a honeycomb adsorber

A solar assisted adsorptive desiccant cooling process has been experimentally tested. This study aimed to investigate an actual performance of the cooling process with a typical configuration (one desiccant wheel, one sensible heat exchanger and two water spray evaporative coolers) driven with solar heated water. The performance was examined in terms of COPs (thermal coefficient of performance based on solar irradiation), Temperature decrease (temperature difference between outside air and supply air) and cooling effect CE (=enthalpy difference between outside air and supply air) at various operating conditions of regeneration temperature, air condition of ambient air and solar irradiation. Stable irradiation at a clear sky gave the desiccant cooling process a higher dehumidifying performance. Temperature decrease and COPs in this condition were 10 degrees C and 0.41, respectively. Unstable irradiation at somewhat cloudy made the system lower dehumidifying performance. However, decrease of the cooling performance was comparably small due to buffering effect by thermal storage in the circulating water. At higher humidity condition, the amount of dehumidified water became higher than that dehumidified at low humidity condition due to increasing relative humidity of outside air or effective adsorption capacity of the desiccant rotor. However, resulting temperature decrease in this condition was just 6.9 degrees C. This behavior is mainly due to humidity increase and simultaneous temperature rise in the dehumidified air. In this situation, an effective evaporation in the following water spray evaporative cooler did not occur.