Experimental study of the optimal mixing ratio of metallic additives for improving the performance of the solar activated carbon-methanol adsorption refrigeration system

An activated carbon–methanol system can run on low heat (70–100°C). Methanol is dependable and works well with activated carbon because of several benefits, including an appropriate latent heat of evaporation, a low freezing point, and negligible copper corrosion and steel at temperatures below 100 °C. An experimental study of the thermal performance by increasing the adsorption bed thermal conductivity was conducted. Using0 10 % 20 and %30 % of metallic copper powder with activated carbon to improve the bed thermal conductivity. A sample is prepared with 20 % copper powder to find out the improvement of heat transfer characteristics to the cooling effect. The temperature gradient has been tested with two flow rates to examine the coolant performance and increase. Solar energy can be effectively utilized based on low-grade temperature consumption in such systems. This work aims to make an experimental investigation of the thermal performance of an activated carbon-methanol adsorption refrigeration system to study the effect of the enhanced thermal conductivity of the adsorbing bed. Using 0 %, 10 %, 20 %, 30 % of metallic copper powder with activated carbon to enhance the thermal conductivity of the bed, providing a significant improvement in the system efficiency, specific cooling power (SCP), and coefficient of performance of adsorption cooling. It is found that copper filing with a mass concentration of 20 % are appeared the optimal ratio metallic additive to enhance the thermal performance of the system. Moreover, the effect of the hot water flow rate is studied. Results indicated that the addition of 20 % metallic copper filings to the activated carbon lowered the evaporator temperature to reach -5 and -10 °C for heating water flow rates 3 and 2 LPM, respectively. Also, the addition of copper filing enhances the cycle COP of the system by 49 % and 46 % at hot water flow rates of 2and 3 LPM, respectively. The highest cycle COP of the current system reached was 0.92 for the condition 20 % additives at 3 LPM hot water flow rate. Owning the feature of great solar energy availability and the long daily sunny hours, solar-powered adsorption cooling systems have promising potential applications in Egypt. A mathematical model of the system performance is also studied.