Analysis of Spot Cooling in an Underground Subway Station

Railway platform spot cooling has become an increasingly attractive means to improve thermal comfort conditions of existing subway stations. This paper presents a systematic approach to evaluate the effectiveness of platform spot cooling. The subway environment is first analysed by a simple onedimensional network model, which is able to estimate the bulk air temperature from the available spot cooling. The localized effects of spot cooling are then investigated using CFD. Three scenarios are examined, including two trains stopped in the station, one train passing, and two trains crossing through the station. The results indicate that the designed spot cooling can improve platform conditions significantly by as much as 17 F (9.5K). This is despite the train piston effects, which cause disruption of the cool air layers along the platform, and could reduce the effectiveness of spot cooling by 50%.