Comparative Studies on Solar Assisted Silica Gel- Water and Activated Carbon-Methanol Based Adsorption Refrigeration System

The ever increasing cooling demand and the environmental concern have made in search of alternative refrigeration and for the last few decades, the energy efficient cooling systems utilizing refrigerants of no negative impact on the environment are explored. In this view, heat-driven refrigeration systems like vapour adsorption refrigeration is one of the favourable alternatives. Though adsorption cooling devices are capable of producing desirable cooling effect with a relatively low heat source temperature, their coefficient of performance (COP) is low in comparison with the existing cooling technologies. Therefore, to solve the environmental, economic and technical issues, the research is still in progress in this area. It is evident from the literature that, the performance of adsorption refrigeration depends on selecting the working pair such as silica gel-water, activated carbon-ammonia, zeolite-water etc. and driving temperature. This paper presents the comparison of performances of solar assisted twin bed adsorption refrigeration which employs silica gel-water and activated carbon-methanol as working pairs. Results are found to be good with continuous cooling in the evaporator using low temperature source of heat and the lowest temperature achieved in the evaporator for silica gel-water is 11°C and for activated Carbon-Methanol is 2°C. The coefficient of performance obtained is higher for silica gel based system than that of Activated carbon based system.