Effect of heating time of adsorber-collector on the performance of a solar adsorption refrigerator

This paper presents a numerical study of heat transfer inside the adsorber-collector of a solar adsorption refrigerator using the activated carbon AC35-methanol pair. The objective is to estimate the amount of the heat loss through the adsorber-collector, during the solar heating phase, and to determine the effect of heating time on the thermal efficiency of the system. The numerical results showed that the heating time is the most important factor affecting the amount of energy loss. It has shown that the shorter heating time corresponds to the higher efficiency of the adsorber-collector. In addition, a new optimal coefficient of performance, COP _optm, is proposed to determine the number of adsorbers to be added to a machine. This latter is considered for consuming an energy equivalent to that received by the adsorber-collector. These additional adsorbers use a heat transfer fluid, coming from the adsorber-collector, instead of direct heating by solar radiation. An application example is presented using experimental results obtained from the literature. It has shown that the number of the additional adsorbers can reach three adsorbers.