Why Ventilation Systems in Tunnel Required?

Ventilation system is an indispensable part of tunnel project. Ventilation ensures adequate air quality inside the tunnel to prevent fire and control the spread of smoke. Vehicle tunnels, such as roads, railways and metro, often require high air quality during normal operation. Mine tunnels also require adequate ventilation to meet physiological, cooling and smoke control requirements.

The purpose of tunnel ventilation

1. To provide fresh air inside the tunnel.

2. To exhaust out smoke and gases that are harmful to health and have the potential to explode.

3. To control the temperature inside the tunnel to prevent fire caused by excessive temperature.

Types of Tunnel Ventilation Systems

There are many types of tunnel ventilation systems, mainly including natural ventilation and mechanical ventilation. ‌Natural ventilation mainly relies on the piston action of the car and the action of natural wind, ‌without the use of fan equipment, to discharge harmful gases and smoke from the tunnel. ‌

Mechanical ventilation includes a variety of methods, ‌such as longitudinal, ‌semi-lateral, ‌lateral and hybrid ventilation system. ‌Among them, ‌longitudinal ventilation includes jet type, ‌duct type and nozzle type, ‌shaft type, etc. ‌The choice of mechanical ventilation method depends on the specific conditions and usage needs of the tunnel.‌ For example, ‌longitudinal ventilation is to introduce fresh air from one opening and ‌discharge polluted air through another opening. ‌

In addition, tunnel ventilation methods also include duct ventilation, tunnel ventilation and wind wall ventilation. Each of these methods has its own characteristics and is suitable for different types of tunnels and specific working environments.