What are the applications of rail transit above the pipe
Information summary:The core of the pipeline layout above the rail transit (including various pipelines laid at the top of tunnels, above platform canopies, and above elevated line bridges) is centered around the three major needs of "safe operation, functional matching, and environmental adaptation" of rail transit, to achieve functions such as water supply and drainage, energy transmission, communication signals, a
The core of the pipeline layout above the rail transit (including various pipelines laid at the top of tunnels, above platform canopies, and above elevated line bridges) is centered around the three major needs of "safe operation, functional matching, and environmental adaptation" of rail transit, to achieve functions such as water supply and drainage, energy transmission, communication signals, and fire emergency. Its application scenarios focus on the entire process of rail transit construction and operation, covering core areas such as underground tunnels, elevated lines, and station hubs. The following provides a detailed analysis based on specific functional requirements and scenario characteristics:
1、 Water supply and drainage system: ensuring operational and firefighting water demand
1. Fire water supply pipeline
Application scenarios: underground tunnels, station halls/platforms, and areas under elevated station canopies;
Core function: Provide stable water sources for the fire protection system of rail transit and adapt to emergency fire extinguishing needs;
Scene adaptation:
Underground tunnel: The pipeline is laid along the top or above the side walls of the tunnel, connecting the section fire hydrant and sprinkler system to ensure that high-pressure firefighting water can be quickly provided in case of a fire at any position inside the tunnel; The pipeline is made of anti-corrosion and high-temperature resistant materials (such as seamless steel pipes and coated steel pipes) to resist the humid and vibrating environment inside the tunnel, while also having anti-collision protection (with protective sleeves installed);
Station area: Fire main pipelines are laid above the platform canopy and at the top of the station hall, with branch connections to platform fire hydrants and automatic fire suppression systems. The pipeline layout avoids electrical equipment and densely populated areas to ensure that evacuation routes are not affected during firefighting operations.
2. Drainage and flood prevention pipelines
Application scenarios: top of underground tunnels, above both sides of elevated railway bridges, station roofs;
Core function: Discharge rainwater and tunnel leakage water to avoid water accumulation affecting the safety of rail transit operation;
Scene adaptation:
Underground tunnel: Blind drainage pipes and collection pipes are laid on the top to collect leakage water from the tunnel wall, which is guided to the interval drainage pump station through a slope to prevent water accumulation from eroding the track and electrical equipment; The pipeline is made of wear-resistant and anti clogging materials (such as HDPE double wall corrugated pipes), suitable for installation in narrow tunnel spaces;
Elevated line/station roof: Rainwater pipes (such as PVC-U drainage pipes, stainless steel drainage pipes) are laid above the canopy and bridge body, combined with a siphon drainage system to quickly discharge rainwater, avoiding rainwater dripping and affecting platform passengers or road traffic below; The pipeline interface adopts a sealed connection to prevent rainwater from leaking into the electrical control cabinet and track area.
3. Domestic water supply pipeline
Application scenarios: above station concourse, platform staff lounge, restroom, maternity and baby rooms, and other areas;
Core function: Provide clean water sources for domestic water facilities in the station;
Scenario adaptation: Food grade stainless steel pipes or PPR pipes are used and laid along the ceiling of the station, avoiding electrical circuits and high-temperature equipment. Insulation layers are installed on the pipes to prevent condensation and dripping; The branch pipeline is connected to the water point through reserved holes to ensure stable water supply and not affect the appearance of the station.
2、 Energy transmission system: supporting power and lighting supply
1. High voltage power supply cable protection conduit
Application scenarios: at the top of underground tunnels, in cable trays above elevated line bridges, and above station distribution rooms;
Core function: Protect high-voltage power supply cables (such as 10kV/35kV traction power supply cables) to ensure the safe transmission of electrical energy in the traction and power systems of rail transit;
Scenario adaptation: High strength PVC-C power pipes, MPP power pipes or steel pipes are used, which are resistant to high temperature, aging and electromagnetic interference; The pipeline inside the tunnel is laid along a dedicated cable tray at the top, maintaining a safe distance (usually ≥ 0.5m) from the communication signal pipeline; The pipeline is fixed above the elevated line bridge through cable trays to prevent cable damage caused by wind, rain, and vibration, and to facilitate maintenance and repair.
2. Low voltage distribution and lighting pipelines
Application scenarios: at the top of station halls/platforms, above lighting areas in tunnels, and at the top of equipment rooms;
Core function: Transmit low-voltage electrical energy (such as 220V/380V) to power station lighting, ventilation, air conditioning, monitoring and other equipment;
Scenario adaptation: Flame retardant PVC conduit and metal wire conduit are used, laid along the ceiling or above the equipment interlayer, with neat and orderly pipeline layout and clear labeling; The lighting pipeline inside the tunnel is installed tightly against the top wall, using anti vibration fixed brackets to prevent the pipeline from falling off due to vibration caused by train operation; Metal pipelines have grounding protection function to prevent the risk of electrical leakage.
3、 Communication signal system: ensuring operation and information transmission
1. Communication optical cable protection pipe
Application scenarios: cable trays at the top of underground tunnels, communication bridges above elevated line bridges, and above station communication rooms;
Core function: Protect fiber optic cables to ensure stable data transmission for rail transit dispatch communication, train signals, video surveillance, and passenger information systems (PIS);
Scenario adaptation: High density polyethylene (HDPE) silicon core pipes and coated steel pipes are used, which have low friction, tensile resistance, and corrosion resistance characteristics, making it easy to install and maintain optical cables; The pipelines inside the tunnel and the high-voltage power supply pipelines are laid in separate slots to avoid electromagnetic interference; The pipeline inside the station is laid along the top ceiling or dedicated communication shaft, connecting the equipment in the computer room with the communication terminals (such as broadcasting, cameras, and display screens) on the platform and in the station hall.
2. Signal control line pipeline
Application scenarios: signal cable trays at the top of underground tunnels, above station signal equipment, and above trackside signal machines;
Core function: Protect signal control lines, transmit train operation control signals (such as ATP, ATO signals), switch control signals, etc;
Scenario adaptation: using flame-retardant PVC or metal pipes, with anti-interference and anti damage characteristics; The pipeline laying path should be shortened as much as possible to reduce signal attenuation; The pipeline inside the tunnel is located near the installation position of the signal equipment, and can be quickly connected through reserved interfaces to ensure the real-time and correct transmission of signals.
4、 Ventilation and Air Conditioning System: Optimizing the Interior and Station Environment
1. Tunnel ventilation ducts
Application scenarios: at the top of underground tunnels, above the connecting section of section ventilation shafts;
Core function: To achieve air circulation inside the tunnel, discharge exhaust gases (such as carbon monoxide and nitrogen oxides) generated by train operation, introduce fresh air, and provide smoke exhaust channels in case of fire;
Scenario adaptation: High strength fiberglass ducts and galvanized steel sheet ducts are used, which have the characteristics of corrosion resistance and high temperature resistance (can withstand temperatures above 300 ℃ in case of fire); The pipeline is laid in sections along the top of the tunnel, and the air volume and direction are controlled by fans. During normal operation, ventilation is maintained, and in case of a fire, it switches to smoke exhaust mode to guide smoke to be discharged into the ventilation shaft, ensuring the safety of personnel evacuation.
2. Station air conditioning and ventilation ducts
Application scenarios: inside the suspended ceiling of the station hall/platform, above the equipment room, and at the top of the transfer passage;
Core function: Provide cooling, heating, and ventilation services for the station, maintain comfortable indoor temperature and air quality;
Scenario adaptation: Adopting galvanized steel sheet air ducts and composite air ducts (such as phenolic aluminum foil composite air ducts), with insulation, noise reduction, and anti condensation characteristics; Reasonable layout of pipelines along the top ceiling, avoiding lighting fixtures, cameras, and sprinkler heads, and connecting branch pipelines to air conditioning units and air supply outlets; Large transfer stations achieve multi zone ventilation linkage through upper air ducts, improving the operational efficiency of air conditioning systems.
5、 Special function pipeline: adapted to the special needs of rail transit
1. Fire smoke exhaust duct
Application scenarios: top of underground tunnels, top of station halls/platforms, and above transfer passages;
Core function: Quickly release smoke during a fire, reduce the concentration of toxic gases, and create a safe environment for personnel evacuation;
Scenario adaptation: High temperature resistant and fire-resistant air ducts (such as fireproof board air ducts and stainless steel air ducts) are used, with a fire resistance limit of ≥ 1.5 hours. The smoke exhaust ducts and ventilation ducts in the tunnel can be shared and switched through valves; The smoke exhaust duct in the station is connected to a dedicated smoke exhaust fan, and the duct layout is avoided above the evacuation passage to ensure rapid smoke discharge.
2. Sprinkler and fire extinguishing medium pipelines
Application scenarios: on top of station equipment rooms, above distribution rooms, and above key equipment areas in tunnels;
Core function: Transport sprinkler water and gas fire extinguishing media (such as heptafluoropropane) to achieve rapid fire extinguishing in the early stages of a fire;
Scenario adaptation: The sprinkler pipes are made of galvanized steel pipes and laid in a grid pattern along the top of the equipment room. The sprinkler heads are evenly distributed to ensure coverage of all equipment areas; The gas fire extinguishing pipeline adopts seamless steel pipes, connecting the fire extinguishing agent storage tank and the spraying port. The pipeline has strong sealing to prevent the leakage of the fire extinguishing medium; Special fire extinguishing pipelines are laid above key equipment (such as traction inverters) in tunnels to meet the fire extinguishing needs of narrow spaces.
3. Cable cooling pipeline
Application scenarios: High voltage cable dense areas at the top of underground tunnels, high-power cable channels above station distribution rooms;
Core function: To cool down high-voltage cables, prevent insulation aging caused by overload heating, and ensure power supply safety;
Scenario adaptation: using internal spiral cooling water pipes or air cooling pipes, laid in parallel with cables; The cooling water pipe takes away the heat from the cable through circulating water, while the air cooling pipe introduces cold air through a fan for cooling; The pipeline is made of corrosion-resistant material and maintains a safe distance from the cable to avoid affecting the insulation performance of the cable.
6、 Core application value and technical requirements
1. Core application value
Function integration: By arranging various pipelines in the upper space, centralized configuration of functions such as water supply and drainage, energy, communication, and fire protection can be achieved, avoiding the occupation of core spaces such as track areas and passenger passages, and improving the utilization rate of rail transit space;
Security guarantee: The pipeline adopts specialized protective materials and fixing methods to resist environmental influences such as vibration, humidity, electromagnetic interference, etc. during rail transit operation, ensuring stable operation of various systems and reducing safety risks;
Convenient operation and maintenance: The layout of the upper pipeline is standardized and clearly marked, making it easy for maintenance personnel to carry out maintenance and replacement without affecting operations (such as during nighttime shutdowns), shortening maintenance time.
2. Key technical requirements
Material adaptation: Special materials that are corrosion-resistant, vibration resistant, high/low temperature resistant, flame-retardant, and fire-resistant should be selected to adapt to the complex environment of rail transit (such as wet underground tunnels, wind and rain erosion on elevated lines, and dense station personnel);
Installation specifications: Anti vibration brackets and seismic hangers are used for pipeline fixation, which meet the seismic grade requirements of rail transit (usually ≥ 7); The pipeline interface is sealed reliably to prevent water leakage, air leakage, and liquid leakage;
Safety distance: Different types of pipelines (such as high-voltage power supply pipelines and communication pipelines, water supply and drainage pipelines and electrical pipelines) need to maintain the prescribed safety distance to avoid electromagnetic interference, leakage pollution and other problems;
Emergency adaptation: Emergency pipelines such as firefighting and smoke exhaust need to have rapid response capabilities and be linked with the rail transit emergency dispatch system to ensure quick start-up in case of emergencies.