Tunnel fan The mode of ventilation in a tunnel
1. Longitudinal type
Longitudinal ventilation, relatively low cost, operating costs are low, but it will make pure gas accumulation in the tunnel entrance, if there is a fire, the fire will be extended along the longitudinal, then the rescue personnel will be difficult to enter the tunnel, so it can only be used for one-way long way tunnel.
2, horizontal type
Horizontal ventilation generally, the cost and operating costs are relatively high, air inlet duct is located above the lane or square, exhaust duct is located below the lane, which leads to cyclone downward activity, is beneficial to eliminate fire, easy to rescue personnel to enter, not easy to accumulate harmful gas, breathable better, suitable for a long way of tunnel.
3, semi-horizontal type
The semi-horizontal type is cheaper than the horizontal type, but the effect of ventilation and fire suppression is not as good as the horizontal type. The semi-horizontal air intake duct is generally set above the driveway, but there are also those set below the driveway. The exhaust duct is set below the driveway. So it's good for 1,000 to 3,000 kilometers of tunnels
4. Lateral flow
Lateral flow is generally arranged on both sides of the driveway. Fresh air is pressed into the driveway through one side wall and inhaled into the exhaust duct through the other side wall. It is mostly used for installation in the underwater tunnel.
Different ventilation modes of tunnel fans have different characteristics and applicable environments, so it is necessary to understand each ventilation mode, in order to choose the appropriate ventilation mode according to the construction environment, so that the use of tunnel fans is more safe and reliable.