1 Tunnel Ventilation Overview

The tunnel of the urban rail transit system generally uses the piston ventilation, that is, the piston wind caused by train operation. However, in order to meet the needs of ventilation and smoke in the normal and emergency state of the interval tunnel, the tunnel ventilation system with a large ventilation capacity in the underground interval tunnel is still required to ensure the safety of the interval tunnel. The tunnel ventilation system includes two parts: interval tunnel ventilation system and station tunnel ventilation system. Division tunnel ventilation system: Ventilation of the tunnel when the train is parked in the interval tunnel, and smoke is discharged when a fire occurs. Station tunnel ventilation system: The heat emitted by the air -conditioned condenser when the train is parked at the platform is discharged in time to reduce the impact on the tunnel and station air -conditioning system. When a fire occurs in the rail area or platform, it is used as the main smoke exhaust equipment.

As the main equipment for tunnel ventilation, the tunnel fan is a two -way (positive and reverse) axis flower, which is located in the equipment houses, interval ventilation rooms, and intermediate tunnel wind rooms at the ends of the station. The positive rotation of the tunnel fans is that the fan is exhausted from the tunnel to the outside atmosphere, and the reversal is that the wind turbine to the tunnel. In the industry, its equipment code is generally "TVF-XXX-XX".

The tunnel fan uses high -power motors as its main component. One of the significant features of these motors is: the general power is large, and it reaches 110kW, and the start current is large. In addition to using a soft starter for protection, for the requirements of energy saving, individual tunnel fan uses inverter technology, that is, the tunnel fan is in a low -frequency working state during the operating time period, acting as the function of rail heat discharge. In the non -operating time period, or according to needs, such as half an hour before departure in the morning and half an hour after the operation, enter the industrial frequency operation, giving the interval tunnel exhaust air. In the fire mode, the comprehensive monitoring system can perform the corresponding mode for smoking.

1.1 Cool the tunnel equipment

The subway tunnel is a relatively closed environment. The heat emissions generated by various equipment in the tunnel are difficult. During the operation of the train, a large amount of calories are also produced. Failure and even misunderstanding. If the temperature is too high, it affects the operation of the signal device, and even causes the train's driving safety accidents and late. Therefore, in the normal period of time, in addition to the piston wind of the train for heat discharge, the tunnel ventilation system is a relatively effective heating method. gas.

After a day of operation, such as 6: 30-23: 30, the entire operation time is as long as 17 hours, and a lot of heat and exhaust gas will be gathered in the tunnel. In this environment, people will not only feel very sultry, but they will not only feel very sultry. And feel that the air is suffocating. When carried out related operations in the tunnel, it will feel uncomfortable, affect work efficiency, and may even have hidden safety hazards for construction. Therefore, under normal circumstances, after collecting the car every night, it will be ventilated for half an hour at night.

1.2 Provide functions such as ventilation and smoke discharge in emergencies

When a certain interval is blocked, the tunnel ventilation system will be vertically ventilated in the same direction as the driving. When the system is designed, only one side obstruction occurs at the same time of the left and right lines in the same interval. If the up and down obstruction occurs at the same time on the left and right lines of the same interval, the air supply method of the left and right lines should be used as a reference. Essence When a train occurs in the station tunnel, the ventilation system of the station tunnel and the tunnel fan on the side will be coordinated to eliminate the flue gas. At the same time, the shielding door will be opened to evacuate. Fan. When the train is running, a fire should be driven to the station as much as possible. Passengers, smoke and fire extinguishing the fire at the front station. When the train fires and the interval tunnel is parked, the pre -designed design is implemented according to the location of the train and the fire location of the train. Fire operation mode.