Numerical simulation on exhaust components and heat removal effect of heat exhaust systems in underground railway stations

Taking a standard underground railway station as the research object, this paper uses CFD software to simulate and calculate the heat exhaust temperatures at the bottom and top of the rail during the period of train stop. It is found that from the perspective of exhaust components, the proportion of the air exhaust at the rail top (OTE) from condensers, tunnel and station is 66%, 11% and 23%, respectively, and the proportion of the air exhaust at the rail bottom (UPE) is 3%, 42% and 55%, respectively. The proportion of UPE from the station is more than 50%, which will cause a waste of cooling capacity in the station, and even lead to the situation that the temperature of UPE is lower than the air temperature in the tunnel. From the perspective of heat exhaust effect, the heat emission of the condenser at the train top is discharged by 22% and 1% respectively by OTE and UPE, the heat emission of the resistance box and the brake shoe at the bottom of the train is discharged by 5% and 29% respectively by OTE and UPE, and the heat removal effect of the heat exhaust system is poor. According to the simulation results, theoretical heat dissipation, measured temperature and other parameters, the average exhaust air temperatures of OTE and UPE are calculated and compared with the measured data, and it is found that the calculated values are basically consistent with the measured values, which verifies the accuracy of the simulation calculation.