Heat and mass transfer of composite desiccant wheels based on different substrate materials

In this paper, the performance of heat and mass transfer of composite desiccant wheels based on different substrate materials have been researched. First, the parameters of substrates were researched including of main chemical compositions and basic thermal parameters. Second, the lithium chloride doped silica gel adsorbents based on ceramic fiber paper, filter paper and glass fiber paper were prepared by the impregnation co precipitation method and then the adsorption performance of desiccant material has been experimental studied. The experimental results indicate that the saturated adsorption performance is basically same as ceramic after soaking treatment by lithium chloride. But the production cost and intensity of ceramic fiber paper and filter paper are much better. So the ceramic fiber paper and filter paper can be used as desiccant substrate. Based on mathematical model, the temperature and humidity in the wheel during both the dehumidification and the regeneration processes are analyzed. It is found that the compound desiccant wheel has a better performance in a climate with moderate temperature or in a climate with high humidity ratio.