Experimental analysis on single stage hybrid solar assisted adsorption refrigeration system

Abstract

In the present energy scenario the continuous increase in the cost and demand for energy has led to more research and development to utilize available energy resources efficiently, in which solar energy is the most promising. Refrigeration systems utilizing solar energy can be effectively employed for vaccine storage, manufacturing ice etc. in rural areas without conventional energy supplies. Compared to solar refrigerator, the conventional PV refrigerator has high installed cost. In liquid absorption systems, rectification is required to avoid the problem of generation of some absorbent with the refrigerant in generator. In the case of solid absorbent systems like CaCl2/NH3 pair, it disintegrates after repeated cycles of operation. Special treatment of the absorbents is needed to obtain hard porous granules, thereby increasing the system cost. Solar adsorption systems, which do not possess these disadvantages, can be fabricated without any moving parts using locally available technology in developing countries. This paper envisages the design, fabrication and tested on the hybrid solar assisted adsorption refrigeration system. This system that combines the solar refrigeration and heating cycle uses working pair as activated carbon and methanol. It consists of a solar parabolic concentrator, water tank, adsorbent bed, condenser, expansion device, evaporator and receiver. The hybrid system has been designed for heating 50 liters of water from 25 OC to 90OC as well as cooling 10 liters water from 25OC to 10OC at a coefficient of performance of 0.85. The experiment results demonstrate that the refrigerator (5 kg activated carbon) has a cooling capacity of 40 to 50 W and COP ranging 0.146 - 0.18 at different evaporator temperature.