Study on Ventilation Blocking Computation in Subway

Gives a mathematical model that describes subway ventilation. The numerical computing method about airflow in subway is developed with a one dimensional unsteady incompressible airflow model and a finite difference method. In the air flow model are considered the friction caused by air between the train surface and the tunnel wall, the changes produced by the tunnel cross section and changes at the joint of the tunnel and the shaft. The various heat sources in subway are analyzed, such as the heat produced by train in motion, illumination, the operation of supplementary equipment, and the people. The different ventilation plans under the most adverse blocking conditions of some subways are simulated and analyzed. The paper offers ventilation measures to guarantee that the condensers of air conditioners can operate normally under the most adverse blocking condition and the rational supply of mechanical ventilation. The paper provides reliable theoretical basis and a powerful tool for the research and design of subway environmental control.