Experimental Investigation on Adsorption and Regeneration Behavior of Silica Gel Powder by using Solar Powered Desiccant Coated Heat Exchanger

The desiccant material is a material which has ability to remove moisture from air. According to the physical and chemical properties, there are two types of desiccant material namely solid desiccant material and liquid desiccant material. In this experimental study, solid desiccant material is used. Solid desiccant material adsorbs moisture from air due to water vapour pressure difference. Some common examples of solid desiccant material are silica gel, activated charcoal, molecular sieve and activated alumina. In recent years, numerous researchers have experimentally and theoretically investigated the adsorption and regeneration behavior various solar desiccant materials. Singh et al. [1] experimentally investigated the regeneration behavior of silica gel by using multi self regenerator. The required regeneration temperature varied between 42°C to 72°C with a variation in velocity of 0.175 m/s to 0.55 m/s. Techajunta et al. [2] experimentally and theoretically investigated adsorption and regeneration behavior of solid desiccant material for the application of air conditioning. Ge et al. [3] experimentally compared silica gel and polymer coated fin-tube heat exchangers. It was found that the DCHE overcome the adsorption heat during desiccant dehumidification process and achieve good dehumidification performance under given conditions. The SCHE performed better as compared to the polymer coated heat exchanger. Ge et al. [4] developed a mathematical model to predict the performance of SCHE cooling system under ARI summer condition and optimized the copper tube external diameter and distance between the fins. Ge et al. [5] developed a mathematical model of a self-cooled solid desiccant cooling system by the combination of DCHE and regenerative evaporative cooler. The performance of the system was investigated under ARI summer condition and effect of outdoor air condition was analyzed. It was found that cooling power of the system increased by 30% as compared to DCHE cooling system. Yadav et al. [6] experimentally investigated adsorption and regeneration behavior of different solid desiccant and found that silica gel was the best solid desiccant material among all solid desiccant material. Kumar et al. [7] regenerated the silica gel by using parabolic dish and found that silica gel can be easily regenerated by using solar energy. Kumar et al. [8] experimentally investigated an air conditioning system with various solid and composite desiccant material for the application of heating and humidification. It was found that silica gel is the most suitable desiccant material for particular application.