A phased multi-scale framework integrating EnergyPlus and CFD for thermal comfort-oriented spatial design in high-speed railway stations

High-speed railway stations present significant challenges for indoor thermal comfort due to their complex, non-uniform environments. Existing studies predominantly prioritize energy efficiency over comfort-oriented spatial design. The limited comfort research addressing thermal non-uniformity is predominantly confined to vertical stratification. To address this, this study proposes a phased, multi-scale framework integrating EnergyPlus and computational fluid dynamics (CFD) for early-stage comfort-oriented design. It combines rapid annual-scale parametric screening with detailed spatial analysis. To capture horizontal heterogeneity, two novel indicators – a distributed temperature indicator (ΔTloc) and a spatially weighted indicator (Tsw) – are introduced. Applied to a case study, the framework identifies space height (H) and skylight-to-roof ratio (SRR) as the dominant variables. Seasonally balanced optimization determined optimal values of H = 16.667 m and SRR = 17.347%, improving these indicators by 14.4% and 39.3%. This framework offers a practical, systematic approach for integrating thermal comfort into the early-stage design of high-speed railway stations.