Experimental Evaluation of a Thermally Driven Adsorption Refrigeration System in Ogbomoso Environs

Abstract

Solar energy is the most promising among the available green energy sources and also the remedy to the increasing global warming potential and ozone depletion. This paper presents an experimental evaluation of an adsorption refrigeration system uses solar energy as a source of heat gain to drive the refrigeration system. It consists of a solar collector, an adsorbent bed, a condenser and an evaporator. The effect of variation of the ambient, condenser, evaporator and desorption temperatures on the COP system and SCP cycle with local weather parameters were investigated. A parabolic solar concentrator was built to collect the solar energy to heat the combination of adsorbent, Activated carbon and adsorbate, methanol and the system employed solar energy as the main power supply. The experimental results revealed that the ambient, condenser, evaporator and desorption temperatures were increased by 25%, 4%, 13% and 265% respectively with solar time from 9hr to 13hr. The response of COP and SCP with variation in solar radiation and desorption temperature had higher influence compare to other weather parameters. The collector and thermal efficiencies were 0.014 and 6.98% respectively at the peak inner adsorber temperature of 114.1 ^oC. The respective cycle and net solar COPs of the ARS were 0.408 and 0.00080 at an evaporator temperature of 17.1 ^oC. This study showed that the solar thermal-driven ARS performed well in south-western climatic conditions of Nigeria and can be used to replace conventional refrigeration system to reduce the effect of global warming and environmental pollutions caused chlorofloro-refrigerants.

Keywords: Solar, Adsorption, Refrigeration, COP, Concentrator