To further ensure the normal operation of the station platform fire mode, tunnel blockage and station public area fire mode, to achieve smoke extraction, fire prevention and ventilation functions, to ensure valuable evacuation time for passengers in emergency situations and to ensure normal, safe, stable, fast and effective operation of the metro. The environmental control workshop of the power supply department carries out annual maintenance of the jet fans according to the annual construction operation plan.

 

Tunnel jet fans are mainly used for longitudinal ventilation systems in underground, highway and railway tunnels. The fans are usually hung on the top or both sides of the tunnel and do not occupy the traffic area and do not require a separate air duct; the construction costs are low and it is a very economical way of ventilation with broad market prospects.

Station ventilation systems are an essential part of the metro system, not only to ensure the normal operation of the equipment area and the comfort of staff and waiting passengers, but also as an effective means of smoke extraction when the station is blocked by vehicle fires. Amongst other things, the jet fans, as an important part of the tunnel ventilation system, provide the appropriate air volume when the tunnel is blocked, thus ensuring the air supply and cooling of the vehicles in the tunnel; providing a fast and effective means of smoke extraction in the event of a tunnel train fire, ensuring that the corresponding fans can be correctly activated for ventilation and smoke extraction, facilitating the provision of air and smoke extraction when passengers are evacuated and providing basic protection for personnel evacuation.

 

When our maintenance staff carry out annual maintenance on the jet fans, they need to work at height, fasten the safety belt on the ladder truck, check the bolts and overall lifting of each jet fan, test whether the three-stage electric drive of the fan is normal, whether the wind direction is in line with the prescribed direction, whether the wind speed is up to standard, and whether the current and voltage are normal when the fan starts running, so as to ensure that the jet fans in the zone are in a good, stable and safe, and able to respond to various unexpected events in a timely manner.

The ventilation method for metro jet fans is generally a reversible jet fan. The fans are installed at the top or side of the tunnel and can be ventilated in both directions to achieve two-way ventilation or smoke control; for longer tunnels, a central supply and exhaust shaft must be attached, which is connected to the atmosphere to form a mixed ventilation system. Full transverse ventilation system: supply and exhaust ducts are installed along the tunnel direction to collect fresh air from the wind pavilion. Exhaust air is discharged centrally from the wind tower. The air supply ducts are generally located under the road surface and the exhaust ducts are located in the upper part of the carriageway. Air supply and exhaust air outlets are set at regular intervals between the supply and exhaust air ducts to allow for timely exhaust along the tunnel cross-section under working conditions.

 

The heavy is carried by the electric unit. The power supply for the ceiling air-conditioning unit is 380 V and 50 Hz. The motor can only be connected if the power supply meets the requirements. Once the power is connected, check that the fan is rotating properly. If reversed, stop the machine to change the phase sequence of the power supply. The fan motor should be well earthed and provided with other reliable protection such as overload, overheating and leakage items.

 

It filters, cools, dehumidifies, heats air and introduce fresh air. It is suitable for sending treated air through ducts to places with a certain distance, and is particularly suitable for air conditioning works in small commercial and industrial buildings. There are 13 models and 39 sizes of this series of units with an air volume of 1500-15000 m3/h and a cooling capacity of 0. The appearance of the unit is that of a nylon filter with a nylon screen. The heat exchanger uses a string of copper tubes with aluminium fins, and the heat exchange effect is remarkable after mechanical expansion of the tubes. The ceiling air-conditioning unit should be installed horizontally in the ceiling mezzanine, with the condensate pipe side allowed to be 5‰ lower, but not higher, to ensure the smooth discharge of condensate. Sufficient space should be reserved around the unit for installation and maintenance. The condensate discharge port connected to the unit should be equipped with a sufficiently high water seal. The connection pipe of the surface cooler should be bottom-up and a shut-off valve and filter should be installed at the water inlet.