Numerical Study on Temperature Variation in Adsorption Bed under Solar Insolation

Abstract

The internal temperature change of an adsorbent bed, which is subjected to the solar insolation, has been numerically simulated. As the intensity of the solar radiation changes with the sun movement, the temperature distribution in the bed evolves continually. Based on the configuration of the evacuated tube bed, a two-dimensional model of heat transfer has been established and numerically solved. To identify the effect of the internal cooling mode, three kinds of thermal boundary condition have been applied to the cooling tunnel. The numerical results reveal that the uniform wall temperature condition presents the best cooling effect, while the natural air convection presents the worst effect. In addition, the temperature change of the bed with the bed diameter has been examined, incorporating with the effect of cooling channel size. For the cooling condition of the natural air convection, the sun-facing side of the bed not only warms up the most rapidly, but also shows the highest temperature. In contrast, the temperature rising of the sun-shading side is much less. The temperature difference between the sun-facing side and the sun-shading side can reach 70℃. The non-uniform distribution of the temperature of the bed will hinder the adsorption cooling performance.