The experimental and theoretical analysis on a Trombe wall with photo-thermal composite catalytic purification blinds

Abstract

Trombe wall is one of typical solar passive heating systems, while exists issues of single-function and indoor air pollution. The photo-thermal synergistically catalytic technology has huge advantage on applying solar energy for heating and air purification. This article proposed a Trombe wall with photo-thermal catalytic purification blinds, which realized air purification, space heating and shading. Firstly, the catalytic activity and mechanism of photo-thermal catalytic material MnOx-CeO2/TiO2 were investigated. Then the experimental and model study on the thermal and formaldehyde degradation performance of proposed wall under three blind angles were conducted. Finally, the parameter and energy-saving performance were investigated. The results show that: Firstly, the once-through conversion of MnOx-CeO2/TiO2 with optimal photocatalyst/thermal-catalyst ratio of 10% approached 80% when the catalytic temperature was above 40 °C. The solar radiation decreased the catalytic reaction activation energy and a photo-thermal synergetic catalytic effect was existed. Secondly, the wall had optimal performance when the blind angle was 45° among the three angles of 15°, 45° and 75° explored in the experiment. In a sunny winter day, the air thermal efficiency and total generated clean air approached 40.9% and 205.2 m3/day, respectively. Thirdly, the thermal and formaldehyde degradation performance increased with solar radiation, ambient temperature and air channel height, while the air channel thickness had an optimal value. Finally, the optimal annual blind operation angles in Hefei were suggested. The average annual volume of clean air generated was 46 m3/day, the total reduced heating and cooling loads were 225.8 MJ/m2 and 616.0 MJ/m2, respectively.