자연환기에 따른 도시철도 객실 공기질 특성

Air conditioning of subway cabin is achieved by two separate air conditioners installed on the top of the cabin. Cooling air is supplied through the line duct on the ceiling through the whole cabin indoor evenly, and the return air is exhausted to the center area of ceiling. Depending on the indoor air quality, outdoor air is introduced into the cabin. A part of air is pressurized out through the exhaust duct by the positive pressure condition of cabin indoor. However, cabin indoor is not always maintained in a positve pressure by frequent door opening during operation. Therefore, outdoor air can be introduced through exhaust fan and tunnel air, highly polluted by fine particles can cause a indoor air pollution. In this study, we measured air velocity, pressure difference, and particle concentration in order to reveal the inflow of outdoor air. We found that outdoor air was introduced during the subway acceleration by the inertial force of indoor air.