The function of tunnel fan in tunnel and subway
The tunnel exhaust fan is mainly axial flow. The requirement is that it can operate automatically according to the concentration of smoke and dust in the tunnel. The movable blade adjustable type is appropriate, which can improve the operation efficiency of the fan, and can be reversed in case of fire, so that it can quickly exhaust smoke. The underground railway exhaust fan can be used centrifugal or axial flow, but also universal tunnel fan. Due to setting underground tunnel inside, * is small. Because the exhaust port is on the ground in the city, the fan noise should be low. Jet or axial fans can be used in short tunnels, long tunnels or underground railways. This kind of fan is used by hanging on the ceiling. Because the noise is big, it needs to add muffler hood, and can be reversed according to the wind direction.
Tunnel fan (jet fan) is a special axial flow fan, mainly used in highway, railway and subway tunnel longitudinal ventilation system. Tunnel fans (jet fans) are generally hung on the top or both sides of the tunnel, do not occupy traffic area, do not need to build additional air duct, low civil construction cost; Fan is easy to install, simple operation, maintenance, is a very economic way of ventilation. When the tunnel fan (jet fan) runs, part of the air in the tunnel is sucked from the ~ end of the fan, accelerated by the impeller, and speeded out at high speed from the other end of the fan. This part of the high-speed airflow with high kinetic energy transmits energy to other gases in the tunnel, generating a pressure rise that overcomes the tunnel resistance, thus driving the airflow direction of the downwind jet in the tunnel. When the flow speed decays to a certain extent, the next group of fans continue to work. In this way, the purpose of taking in fresh air at one end of the tunnel and discharging stale air at the other end is realized.