Analysis of heat and mass transfer in the adsorbent bed of a thermal wave adsorption cooling cycle

Abstract

A coupled heat and mass transfer analysis of the adsorbent bed of a thermal wave adsorption cooling cycle is performed. The adsorbent bed is modeled two dimensionally. Governing equations for energy, mass and momentum transfers are solved by Comsol Multiphysics simultaneously. Variations of temperature, pressure, adsorption capacity, equilibrium adsorption capacity and mass transfer coefficient for a finless tube adsorbent bed are presented with multicolored plots. Desorption process is simulated in the model. Results show that the adsorbent bed reaches the maximum cycle temperature uniformly after 5000s. Uniform pressure assumption can be used in the bed due to small pressure gradient during the process. Adsorption capacity decreases from 26.1% to 8.89% in 5000s. Temperature front progresses along the bed creating a thermal wave. The thermal wave length is needed to be short to enhance the bed effectiveness regenerating more heat between the beds of the thermal wave cycle. It can be concluded that a parametric study is recommended for a future work in order to investigate the effects of design and operational parameters on the dependent variables and thermal wave length.