Ventilation for subway stations with adjustable platform doors created by train-induced unsteady airflow

Abstract

At present, subways (rail transit) are undergoing rapid developments worldwide accompanied by massive energy consumption. Train-induced unsteady airflow (TIUA) generates airflow through the entrances and platform doors, which affects the ventilation and thermal environment of subway stations. Adjustable platform door systems are increasingly being installed in subway stations to reduce the energy consumption by utilising TIUA. In this study, numerical modelling was performed by IDA Tunnel software to analyse the air inflow rate (AIR) through the entrances and adjustable platform doors (APDs). Four key factors, namely, the open and closed systems, bypass ducts, train intervals, and adjustable air vents, were analysed. The results demonstrate that for subway stations with adjustable air vents open, the average AIR through entrances with a closed system was 1.99–4.17 times that of the open system. Moreover, the variations of the average AIR through entrances caused by bypass ducts were less than 9.20%, and turning off the bypass ducts increased the average AIR via the APDs from 35.58% to 65.58%, when the adjustable air vents were open. In addition, the results show that the AIR via the APDs was decreased from 32.48% to 80.45% by shutting the adjustable air vents. Therefore, an innovative energy-saving strategy of environmental control system (ECS) was proposed based on the utilisation of TIUA. A winter case to optimize the ventilation control modes of TIUA is discussed. Compared with the worst mode, the heating requirements of subway stations with optimal ventilation control modes of TIUA can be reduced by 62.85%.