【 Weak current College 】 Metro station fire protection system design---Power By 【 China power house network 】

Summary: details the Shanghai Zhongshan North Road Metro station fire design methods, including water and water supply, fire hydrant water supply system and spray water system and fire water tank, antifouling block valve and automatic sprinkler systems, and other design elements are explored, as related design provides reference.
Keywords: fire water systems; automatic sprinkler system; backflow device
　　
Zhongshan North Road station located in Zhijiang Road West to North Zhongshan Road between planning big marketing road ground. The second floor of the station for the underground, island platform. The station is approximately the length, width approximately 224m 19.6m. Fire design including fire hydrant system, spraying water system, fire-fighting configuration and important electrical rooms of gas fire extinguishing system.

1 fire design
Water supply and water supply water and 1.1 method
Use City tap water as the water source. Fire fighting pipes from the urban water supply intake two road. Fire is directly from the urban network pumping, no fire water tank. Water supply system uses production, water and fire water open water supply system, and set the meter and the valve shaft. Fire water system through the fire control pump group of the booster, fire hydrant system formation in the station, the supply pipe fire hydrant water station. Spray water supply system for the supply of wet alarm valve after the station Hall, public area spray platform layer. Fire water system at the same time in a fire, the fire hydrant system extension time 2h, fire sprinkler water supply system for 1h duration.
1.2 system layout
① fire hydrant to water system
Commission, fire hydrant system mainly supply station and adjacent tunnel fire hydrant water. Station fire hydrant water consumption for 20L/s, interval and entrance channel fire hydrant water consumption for 10L/s, requiring any point while the two fire hydrant. Fire pump room, Interior hydrant pumps and spray pumps, fire hydrant pump group includes two fire hydrant pump (each standby).
In the station Hall layer using I-fire box, stand on either side of the public area of the Office floors alternating layout, single side spacing around 45m, Cabinet Interior DN65 single head valve a fire hydrant, hoses, a spare 25m DN19 a multi-functional water gun, another with self-help type hose reel set, fire-box Interior hydrant pump start button, and in case of alarm button outside.
In the platform layer public area landings and platform layer equipment area and length > 20m entrance set II-fire box, box body, Interior DN65 single head valve fire hydrant two, two spare hose 25m, DN19 all-in water gun one, the other with self-help type hose reel set, fire hydrant box set on the Start button, the pump and tank peripherals have alarm button.
Tunnels around every 50m layout a single head single valve fire hydrant, at the same time with hydrant pump start button and fire alarm button, no fire box and ancillary facilities.
② spray water supply system
Station spray water supply system of main supply station Hall, public area spray platform layer. Spray system according to the level of risk II, spray of water consumption is considered 27L/s. Fire pump room, Interior hydrant pumps and spray pump, spray pump group includes two spray pump (each standby). Spray water supply system in the station within the tree-shaped arrangement of nozzles in station station Hall, public area at the top of the platform layer, no ceiling set upright sprinkler, suspended ceiling is set at the droop sprayer, nozzle set spacing to 2.4 ~ 3.6m. Fire pump room, Interior wet alarm valve set, each fire compartment located a flow indicator, spray pump operated by wet alarm valve pressure switch control.
In the outdoor ground set DN150 aboveground fire pump adapter and companion of the two sets of hydrant.

2 questions and discussion
2.1 directly from city pipeline pump, no fire water tank
Fire water tank can be stored in a fire last time indoor and outdoor fire water. Because Zhongshan North Road station for the underground stations, outdoor fire water consumption, and an adequate water supply and water around the water, so the Interior fire water directly from the urban network aspiration. Currently, many cities taking into account the direct from the municipal network pumping will have on the urban water pipes and water pipes under negative pressure damage, interfere with other users in normal use, it requires elevated station set fire water tank (fire pump does not pump water directly from the urban network). To this end, the measures adopted must be the local fire department, get in touch and in water.
2.2 set antifouling block valve
The MTR design specifications "section 3.2.5, paragraph 1, the provisions of paragraph 2:" directly from the water supply pipeline received the following water pipes should be in the water pipes set pipeline backflow device or other effective prevention of backflow contamination: ① individual pick out the fire water pipe, at the beginning of the fire with water; ② from end of urban water supply pipeline of pump directly on the water, the suction pipe up side ". On subway station DN200 fire fles, required the installation of anti-fouling block valve, valve body, valve length > 1.3m should be installed before the floodgate valve, filter and rubber joint, valve after loading gate valve, the valve block length > 3m. Metro station outdoor ground involves a block development, cannot set the backflow device; station interior space is limited, and the valve block the installation of drainage arrangement exists quite difficult. According to the author on subway station fire design experience, recommendations will be set in the valve block, duct ventilation shaft or fire pump. Mainly due to the Metro station fire fles General from air shaft, duct into the station fire pump house, wind, wind-or fire pump sufficient installation space, you can arrange the perfect drainage facilities.
2.3 set automatic sprinkler systems
Having access to the urban rail transportation design code, and other relevant norms, Metro station, the platform layer public areas require setting up automatic sprinkler system. However, the author believes station Hall, public area, set the platform layer of sprinkler system is not suitable for the following reasons:
① Metro station combustibles, decoration materials are made of non-combustible materials, the use of flame-retarding material cableThe Metro station station Hall, public area General platform layer without commercial network.
② Station Hall floor public areas are passengers entering and leaving the station ticket sites, the platform layer public area is a place of temporary stay travellers, equipment area mainly office space and equipment control room, a fire is unlikely, and important electrical equipment room set gas automatic fire extinguishing system.
③ set in accordance with the specifications within a station fire hydrant system and fire. The entire area of the layout of the fire detectors, once there is a fire, could soon find, and staff can make use of fire extinguishers, reel or extinguished the fire in the early days.
④ When fire occurs, nozzle movement so that part of the ground water splashes, causing slippery ground, the effect of evacuation, confusion, will cause unnecessary losses.
④ domestic Beijing, Guangzhou, Shenzhen and Hong Kong MTR Station Hall, public area are the platform layer is not set for automatic sprinkler system.

3 conclusion
In the subway station fire design must implement the "prevention, anti-binding" approach, using advanced effective technology, safe and reliable measures, according to the specification for the design, adapted to local conditions.