The performance investigation on a multifunctional wall with photo-thermal catalytic blinds for heating, shading and formaldehyde removal

A novel multifunctional wall with photo-thermal catalytic blinds (PTC-Blind/TW) for heating, shading and formaldehyde removal was proposed. The system can realize indoor air purification all year by using solar energy, space heating in winter and cooling in summer simultaneously. The hybrid wall system was built and thermal and formaldehyde degradation performance was tested experimentally. The coupled heat, mass and reaction dynamic model was established and experimentally verified. Based on the model, the optimal blind angle control strategy was studied when the system runs in different cities all year. Main results were: (1) Under the solar radiation of 300–900 W/m2, the thermal efficiency, formaldehyde single-through convention and CADR of system were in the range of 20–40%, 30–60% and 20–80 m3/h respectively. (2) For the thermal and purification performance of the system, the fitted degree R2 between the simulation results and the experimental results reaches 80–90%. (3) The optimal blind turning angle operation strategy in Nanjing, Beijing, Xining and Guangzhou was obtained. (4) When applied optimal operation strategy in four cities, the total generated clean air annually, reduced heating loads in winter seasons and reduced cooling loads in summer and transition seasons were in range of 0.8–1.7*104 m3/m2, 86.3–739.5 MJ/m2 and 261.2–388.5 MJ/m2 respectively.