Simulation of CO2 concentration in a underground railway during close mode operation

Selecting the CO2 concentration as an indicator of the air quality in underground railway stations, interval tunnels and carriages, studies the indoor air quality of closed underground railway systems. Based on the basic model of contamination concentration, analyses the ventilation conditions of underground railway stations, tunnels and carriages, and establishes a calculation model of CO2 concentration. Selects a typical underground railway line for simulation of the CO2 concentration changes, and verifies the calculation result by comparing with the field test result. The comparison shows that the simulation result is consistent with the field test result. The calculation method can be used to analyses the CO2 concentration in underground railway at the design stage, thereby helping designers to determine a reasonable scheme and operation mode of the environmental control system of a underground railway.