Optimization of solar collector surface in solar desiccant wheel cycle

This work presents the optimization of a solar collector surface in solar desiccant wheel cycle which for cooling process with typical configuration naming desiccant wheel, heat exchanger and water spray evaporative cooler. In this cooling cycle the thermal solar energy has used to heat the regeneration air of desiccant wheel cycle.The optimum solar collector surface has determined by taking into account of design parameters such as velocity of air, wheel speed, thickness of the desiccant and hydraulic diameter of the desiccant wheel and also operating conditions such as outside temperature, outside relative humidity, regeneration air temperature and total solar irradiance. For this purpose, effect of desiccant wheel parameters has investigated on solar collector surface. After that, optimum design parameters and minimum solar collector surface has calculated.In this cooling process, a mathematical model has used that shows physical properties of air.The calculated values for design condition show that necessary solar collector surface has decreased about 45% in comparison of an empirical model in equal operating conditions.The results of this study show that necessary solar collector surface will be decreased by increasing inlet air temperature, inlet air humidity ratio and solar irradiance and will be increased by increasing the regeneration air temperature.

► Optimized value of solar collector surface will be obtained for design parameters of desiccant wheel. ► Solar collector surface will be decreased from 33.1 m2 to about 15.1 m2 for Tdb = 30 °C and w = 25 g/kg. ► Necessary solar collector surface will be decreased by increasing the outdoor air wet bulb temperature.