Feasibility Analysis of Natural Ventilation of an Internal-Combustion Tract Single-Line Tunnel between 2-4 km in the Plateau Region
(1 School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070;
2 The First Survey & Design Institute of China Railway, Shaanxi Xi'an 710068;
3 School of Mechanical Engineering, Southwest Jiaotong University, Chengdu 610031)
Abstract:
Based on monitoring results indicating harmful gas concentrations in the Guanjiao and Yangbajin tunnels along the Qinghai-Tibet railway in winter and the observed wind speed in the tunnel zone of the Lhasa-Rikaze railway, the recommended natural air speed outside of a tunnel is presented. The reasonable natural air speed value inside of a tunnel was determined and the speed and length of piston air were calculated based on calculations of natural wind speeds determined by thermal potential difference in the tunnel and a one-dimensional unsteady flow simulation for air speed and pollutant concentration in the tunnel. Furthermore, the time period when natural ventilation is available was analyzed for tunnels measuring 3000-4070 m in length. Results indicate that natural ventilation mode may be used during the operation of tunnels less than 3000m. Regarding tunnels measuring 3000-4070 m, natural ventilation may achieve health standards with long-term planning.
SUN San-Xiang-1,
Li-Guo-Liang-2,
Yu-南Yang-3 etc
.Feasibility Analysis of Natural Ventilation of an Internal-Combustion Tract Single-Line Tunnel between 2-4 km in the Plateau Region[J] MODERN TUNNELLING TECHNOLOGY, 2011,V48(5): 101-108