Investigation on the optical path of aerogel glazing system based on the 3D structure

The aerogel glazing system (AGS) is an innovative energy-efficient glazing solution, where the optical path significantly influences transmittance. The complex structure of the aerogel granule layer makes accurately calculating the optical path challenging. To address this, a three-dimensional structural model of the optical path is proposed. First, the optical path and rotation angle of a single granule are calculated. Then, the unit equivalent coefficient is determined using the minimum repeating unit. Geometry optics and calculus are applied to compute the optical path for the entire granule layer. The optical path is input into the optical model to simulate spectral transmittance. Simulation results show the proposed model improves accuracy by 4.75 %, 4.72 %, and 10.1 % for P2.5F8, P2.5F12, and P4F12, respectively, compared to the two-dimensional model. The energy performance of AGS across different climate zones was simulated, considering the total annual heat gain. P4F8 demonstrated the best performance in the Severe Cold, Cold, and Temperate Regions, while P1F16 proved to be most suitable for the Hot-Summer Warm-Winter Region. In the Hot-Summer Cold-Winter Region, the energy performance of P4F8, P2.5F12, and P1F16 were relatively similar. Structural analysis shows that granule size has a greater impact on energy performance than filling thickness.