Computational Study on Desorption of Adsorbent Bed Using COMSOL MultiPhysics in Vacuum condition

Adsorption cooling technology offers great promise for energy savings and lowering greenhouse gas emissions. The present study aims the analysis of heat and mass transfer for silica gel-water adsorbent bed in a vacuum condition using COMSOL Multiphysics. The energy required for the regeneration process is given at the domain boundary as a function of time. The impact of different particle sizes (3mm, 4mm, 5mm) on desorption rate, heat and mass transfer coefficient is studied. From the study, the particle with a smaller diameter has a high desorption rate and mass transfer coefficient. Similarly, increasing the particle size from 3 to 4mm decreased the adsorption rate by 4.26% and from 3 mm to 5mm by 8.55%. It is seen that the increase in the particle size increased the thermal resistance in the bed because of the poor thermal conductivity of the desiccant. Methods to increase the heat transfer rate in bed and optimization of operating conditions should be taken care.