Case study of a two-stage rotary desiccant cooling/heating system driven by evacuated glass tube solar air collectors

A solar driven two-wheel two-stage desiccant cooling/heating system has been installed and operated for an Electronics Plant at Himin Solar Company in China. First, two different configurations and connection types of solar air collectors are analyzed. It is found that the thermodynamic and economic properties of 25 mm alumina are superior to 19 mm stainless steel and two-stage connection type is more suitable for desiccant cooling.This system is designed to satisfy space cooling demand and heating demand. In cooling cycle, the outlet temperature of the solar air collectors is about 60-100 degrees C and their thermal efficiency can reach 50%. For the solar driven two-stage desiccant cooling system the moisture removal can reach 9-12 g/kg and supply air condition is approximately 18 degrees C and 60% RH. Experimental results indicated that the average thermal COP in cooling cycle is 0.97 and the cooling capacity in the range of 16.3-25.6 kW under hot and humidity ambient conditions. The solar COP of system in heating cycle is about 0.45 when thermal efficiency of collector is 50%. Compared to direct heating, heating with humidification can reach a higher state of comfort. (C) 2011 Elsevier B.V. All rights reserved.