Techno-Economic and Emission Analysis of Solar Assisted Desiccant Dehumidification System: Experimental and Numerical Approach /

Abstract

In humid climates, it is challenging to maintain the amount of moisture content in the air for human thermal comfort and industrial applications. Regeneration is an essential process during moisture removal through a desiccant dehumidifier. Commercial desiccant dehumidifiers rely on conventional electric heaters to regenerate desiccant material, accounting for significant energy consumption by such systems. As a green solution to this problem, the present study integrates a flat plate solar air collector (FPSAC) with a desiccant dehumidifier to effectively use solar thermal energy and reduce electrical consumption. Performance evaluation of glazed and unglazed FPSAC-assisted desiccant dehumidifier has been conducted at process air flow rates of 33, 51 and 62 m3/h with a constant regeneration flow rate of 42 m3/h. Both glazed and unglazed FPSAC assisted desiccant dehumidification systems had the highest dehumidification effectiveness and percentage increase in temperature at the flow rate of 33 m3/h, while the highest moisture removal capacity was at 51 m3/h. Maximum dehumidification effectiveness, percentage temperature increase, and moisture removal capacity for the glazed case were 0.4, 66.67%, and 6.14 kg/h, respectively. Experimental results showed that the glazed FPSAC-integrated desiccant dehumidification system outperforms its counterpart in all performance evaluation parameters. Using Transient System Simulation software (TRNSYS), the proposed glazed and unglazed assisted desiccant dehumidification system was modeled and validated with experimental results in terms of regeneration inlet temperature, process air outlet relative humidity, and process air outlet temperature at a flow rate of 33 m3/h. Furthermore, a techno-economic analysis of the solar hybrid desiccant dehumidification system has been carried out. The FPSAC used in this study showcased a 33.57% yearly solar fraction with a solar hybrid system having a payback period of 7.28 years with gasoline as a fuel source for auxiliary energy. In addition, the hybrid system can reduce greenhouse gas emissions yearly by about 0.352 tonnes of CO2 equivalents.