Abstract:

The optimal layout scheme of jet fans under fire condition of emergency rescue station in tunnel portal and the influence of each parameter on the design scheme of fire ventilation are very important. Hence, based on the emergency rescue station project in ZhengzhouWanzhou Highspeed Railway Tunnel portal, the layout scheme of jet fans and its influencing factors under fire condition are studied. And then the advantages and disadvantages of 3 ventilation schemes, i.e. fans in main tunnel portal section, fans in main tunnel portal section and parallel heading portal section, and fans in main tunnel portal section and cross passage, are studied by means of network ventilation algorithm. Finally, the influence degree and rule of natural wind, fire source location, fire scale and longitudinal slope of tunnel on wind speed in the main tunnel and at the protective door are studied. The results show that: (1) The amount of jet fans needed is the smallest when the fans are arranged in the main tunnel portal section and parallel heading portal section at the same time. (2) The natural wind in the tunnel has the greatest influence on the wind speed in the main tunnel of tunnel portal section, while the fire location has a relatively small influence, and the fire scale and longitudinal slope of tunnel have the same influence degree; compared with the main tunnel, the influence of various factors on the wind speed at the protective door of tunnel is relatively small. (3) When considering the fire scale, longitudinal slope, fire source location and natural wind in the tunnel, the total power of the fan meeting the requirements of fire ventilation is 2.5 times that of the fan without consideration of the above factors. And the total power of the fan is 3.0 times that of the fan without consideration of the above factors under fire condition.

Key words: highspeed railway tunnel, tunnel portal, emergency rescue station, fire ventilation, parameter sensitivity