Abstract:

There are 2 intermediate ventilation shafts with length of 6.7 km in long tunnel section on Zhengzhou Subway Line No. 17, Air Port StationXingang Eight Road Station Section. In order to study the optimum ventilation scheme for the tunnel section, the numerical calculation model of the whole route is established by software subway environment simulation (SES). And then the fresh air volume, temperature, preliminary investment and traction energy cost of the tunnel section under different piston ventilation modes of intermediate ventilation shaft are analyzed to obtain optimal ventilation scheme. The results show that: (1) Under the double piston ventilation mode, the average air temperature in longterm peak hours of tunnel is the lowest; and the fresh air changing time in tunnel is the most and greater than 3 per hour. (2) The preliminary investment of the double piston ventilation mode is the highest; but the traction energy cost is the lowest; compared to the other ventilation schemes, the total traction energy cost saved after 26 years′ operation can offset the additional investment. (3) The double piston ventilation mode is recommended considering tunnel environment and engineering economy. The results can provide reference for the design of subway tunnel ventilation system of the similar projects in the future.

Key words: long metro tunnel section, intermediate ventilation shaft, ventilation scheme, subway environment simulation (SES), double piston ventilation mode