Thermal sensation in transient conditions at subway stations during the winter

Abstract

Due to the huge difference between outdoor and indoor temperatures during the winter, subway riders inevitably feel thermal discomfort entering and exiting the air-conditioned station interiors and trains. This paper attempts to identify the thermal sensation response resulted from the lagging effect of the transient thermal conditions in a subway station, which consist of "cold-neutral-warm" and "warm-neutral-cold" phases. The results show that the transient variation in ambient temperature causes abrupt sensation responses and affects thermal sensation vote (TSV). Based on multiple conditions and effective temperature difference, the author examines the temporal TSV variations in both the hot transition and cold transition, and calculates the exact values by the respective equations. Moreover, the thermal sensation expectation is used to represent the thermal sensation of unidirectional or bidirectional passenger flows moving across different sections in the transitional space, and is calculated based on the TSV value in unidirectional or bidirectional passenger flows. The findings shed new light on the optimization of subway operation mode.