Experimental and Numerical Investigation on the Regeneration Process of Passive Solar Shading and Dehumidifying System for Hot-humid Areas

Abstract

This paper presents an idea of passive solar shading and dehumidifying system to improve the indoor thermal environment and energy conservation in hot-humid areas. Elementary investigation on the regeneration of this passive system is undertaken. First, the test apparatuses are constructed for solar shading dehumidifier and silica gel is chosen as the desiccant material; the effects of internal surface color and the orientation of the test apparatus on the regeneration process are experimentally investigated. Then a mathematical model and valid Fortran program made to calculate the regeneration process are checked by the experimental results, it is used to analyze the influences of airflow rate, glass layer, the thickness of desiccant material and insulation material. The distribution and variation of moisture content and air temperature at different point in the apparatus are also obtained by numerical calculation. Experimental results and numerical results show that: lower airflow rate is beneficial to the regeneration of this passive system, the airflow rate influences the regeneration process greatly; thinner desiccant material layer can be quickly and fully regenerated, but adsorbs moisture easily; single glass layer and black internal surface are more affective of using solar energy to regenerate the desiccant material; insulation material has almost no effect on the regeneration process. The numerical results also show that desiccant material is more dehydrated when it is far from the inlet of air.