Effect of air flow on temperature distribution in subway cabin during heating

초록

Thermal comfort in subway cabin is very important in operating subway because there are many complaints from passengers about the temperature in the cabin. Especially, the frequent opening of doors causes the serious temperature drop in the cabin in winter season, and passengers nearby the doors may feel thermally uncomfortable. There can be several methods to reduce this temperature drop, and the use of additional air flow inside the cabin was considered here. Additional air flow in the cabin was prepared by using two fans while the ambient temperature was kept at 0 ℃, and the heaters were on. Two fans were located at 0.5 m height from the floor, and the wind directions were varied vertically upward or downward, and horizontally headed inner or outer. At each experimental conditions, the door opening was repeatedly 10 times, and the temperature change inside the cabin was monitored. Temperature drop was smaller when the wind direction was vertically downward, because the air flow blocks the inflow of cold air from lower part of the door. While temperature drop was larger when the wind direction was horizontally headed inner. This study can give a clue to reduce the temperature drop in the cabin by using air flow.