Reallocation of Supply Air in Large Indoor Spaces Considering Thermal Coupling

In large public indoor spaces, such as railway station and airport waiting halls, indoor thermal environment is not always homogenous due to non-uniform indoor occupant distributions. A conventional air conditioning system, which adopts a uniform air supply, easily leads to local overcooling or overheating. Therefore, this paper proposes a supply air reallocation method for a large indoor space to enhance the uniformity of the thermal environment and improve the occupants’ thermal comfort. In the proposed method, the large space is firstly divided into several subzones according to the layout of the supply air terminals. Then, a co-simulation platform, including a building energy model and a computational fluid dynamics (BEM-CFD) model, is established to simulate and identify the thermal coupling between different subzones. The supply air volume of each subzone is then optimized considering the thermal coupling characteristic. The proposed method was applied to a high-speed railway station in China to evaluate the feasibility of the proposed method. The results showed that, compared with the conventional uniform air supply method, the indoor thermal uniformity could be improved by 15.61–31.11% after reallocating supply air, being able to reduce the risk of local overcooling or overheating.