Experimental and numerical study of the airflow and thermal characteristic of non-uniform transpired solar collector
non-uniform transpired solar collector, airflow and thermal characteristics, experiment, numerical simulation
A transpired solar-collector is a device, which is attached to building walls, that uses solar energy to provide preheated fresh outdoor-air before it is drawn into the building through the ventilation system. A transpired collector consists of a heat-collection plate with infiltration holes, an air layer, an air outlet, and other auxiliary components. A transpired solar collector with non-uniform holes is investigated in this paper, and a physical model for it is developed. The model is then simplified to enable effective simulation and subsequently verified by experiments to evaluate the reliability of the simulation results. Furthermore, a multi-factor sensitivity analysis of a transpired solar collector, with respect to airflow and thermal characteristics, is performed using a numerical simulation. In addition, the application of the device is combined with the thermal requirements of the actual building. The results show that the air-layer thickness has the strongest effect on the heat-collection efficiency, which can be increased to 93% when thickness is 30 mm and height ratio is 0.30. This effect is obvious only in the case of non-uniform perforation. Although a high air-velocity can increase the daily heat-exchange by 595.2 W, the average daily air-supply temperature decreases by 34.2 °C. Even though the temperature-target may not be reached when more fresh air is introduced, the reduction of the fresh air heating-load is substantial.
Tsinghua University Press
Dengjia Wang, Meng Gao, Qian Gao et al. Experimental and numerical study of the airflow and thermal characteristic of non-uniform transpired solar collector. Build Simul, 2020, 13(6): 1305–1319.