Dynamic simulation analysis of the regeneration performance of a solar-powered ventilated roof desiccant bed

Human comfort and health are significantly affected by indoor humid environments. Traditional dehumidification methods in buildings often have the problems of high energy consumption, complex structures, and high maintenance costs. Given this, a ventilated roof desiccant bed was proposed in this paper. The heat and moisture transfer process during its regeneration phase was analyzed, a dynamic numerical model for heat and mass transfer was established, and a dynamic characteristics simulation study of the regeneration process was conducted, providing theoretical reference for its practical application. By comparing indicators such as moisture content, effective regeneration time, and regeneration rate, the regeneration characteristics of the desiccant bed under high and low solar radiation scenarios were analyzed. The results indicate that, under the same thickness of silica gel coating, the steady-state moisture content of the desiccant bed under high solar radiation conditions (average 654.0 W/m2) is lower than that under low solar radiation conditions (average 305.4 W/m2). The intensity of solar radiation enhances the regeneration of the desiccant bed, with a regeneration rate of 57.3% under high solar radiation conditions, higher than 52.6% under low solar radiation conditions. Under high solar radiation conditions, the average regeneration amount within the first 3 hours is 8.31 g, and only 0.30 g in the subsequent 3 hours, indicating that the regeneration of the desiccant bed can be basically completed within 3 hours in good weather.