Effects of the thickness and particle size of silica gel on the heat and mass transfer performance of a silica gel-coated bed for air-conditioning adsorption systems

Abstract

The effects of the thickness of silica gel on the metal substrate and the particle size of silica gel in the consolidated layer on the mass and heat transfer performance of the silica gel-coated bed are discussed in this study. In this adsorption bed, the consolidated silica gel layer was coated directly onto the surface of a metal heat exchanger to reduce the heat transfer resistance between the sorbent and metal substrate. The silica gel-coated bed was usually employed as an adsorber for adsorption/desorption water vapor in the air-conditioning adsorption systems. From the results of the dynamic adsorption experiences, good mass transfer performance was observed in the system with small thickness of the sorbent layer and large diameter of sorbent particles. The breakthrough curves obtained in this adsorption bed under different preparation conditions are discussed. The influences of the regeneration temperature and the thickness of sorbent layer on the heat transfer performance of the adsorption bed are also reported.