The civil construction work of the balance underground stations of the first corridor is progressing towards completion.
Presently, finishing and system installation work is being carried out in the four remaining underground stations. UP Metro has begun the installation of Tunnel Ventilation System (TVS) in this section.
The TVS system located at about 16 meters below the ground ensures the safety of travel at the time of metro operations in the underground section.
Important in terms of fire safety
The TVS system acts like the lungs of the underground station and plays a very crucial role during emergency situations like fire. During an accident like fire, the tunnel ventilation fans of the TVS system regulate the direction of the movement of smoke, which helps the passengers in escaping safely. In a situation where a train suddenly stops inside the tunnel, this system maintains normal temperature inside the tunnel.
Similarly, trackway exhaust fans capture the hot air coming out of the air conditioners of metro trains and heat generated due to braking during its operation in the underground tunnel and prevents it from mixing with the platform ambience. This helps in maintaining comfortable temperature for the passengers standing on the platform and station.
Other major components of the tunnel ventilation system such as dampers, sound attenuators and air handling units also play varied roles. Dampers are used to control the flow of air passing through tunnels, shafts etc.
They also transfer the air pressure coming along the train in the tunnel to other tunnel. Nozzle dampers are used to divert the air flow in specific directions in cases of emergency. Sound attenuators are used to reduce the noise generated by tunnel ventilation fans. The Air Handling Unit or AHU collects fresh air from the trackway exhaust fans during summers. Whereas it collects the fresh air from environment in winters and circulates it in the underground station.
Each station of Agra Metro with the tunnel ventilation system consists of 3 trackway exhaust fans, 4 tunnel ventilation fans and 2 air handling units. Apart from these, various types of dampers like fan protection damper, track release damper, draft release damper, nozzle damper and sound attenuator etc. have also been installed.
