What are the main fire-fighting facilities and fire-fighting problems in China's subway?

The following is the related contents about the main fire-fighting facilities and fire-fighting problems of China's subway brought by Zhongda Consulting for your reference.

in order to alleviate the worsening urban traffic problems at present and in the future, some big cities in China have built or are starting to build subways. At present, Beijing, Tianjin, Shanghai and Guangzhou have been put into operation, and Nanjing and Shenzhen are under construction. The subway will become the main means of transportation in major cities in China. The author mainly introduces the fire-fighting facilities of subways built and under construction in China, and analyzes the main fire-fighting problems existing in subways in China.

1 Main fire-fighting facilities in China's subway

1.1 Guangzhou Metro

1.1.1 Four sets of communication equipment ensure the unimpeded fire information

Guangzhou Metro can quickly collect relevant information from four channels. First, the automatic alarm system, the FAS automatic fire alarm system in the station is very sensitive, which can automatically collect fire information in the jurisdiction and quickly transmit it to the station control room and control center, automatically triggering the fire smoke exhaust mode; Second, radio communication, station staff and subway drivers can transmit accident information to the control center through the wireless system; Third, wired communication emergency telephone, staff can contact the control center through wired telephone; The fourth is the CCTV video transmission system in the platform. An omni-directional monitor is installed in the station to collect all the video information in the station in real time.

1.1.2 Fire-resistant materials for building decoration

The train seats of Guangzhou Metro are made of stainless steel, the optical fiber cables in the subway tunnel are made of fire-resistant, flame-retardant, low-smoke and halogen-free materials, the decorative materials of trains and stations are all made of non-toxic and non-combustible materials, and the station section works are made of reinforced concrete structures. These designs reduce the possibility of the station itself catching fire to the lowest point.

1.1.3 fire-fighting facilities are complete

every car on the train is equipped with two fire extinguishers, which is enough to cope with the initial fire in the car. In the station, the fire-fighting facilities are perfect, and enough fire hydrants and extinguishers are equipped according to the specifications. Important equipment rooms are equipped with automatic gas fire extinguishing system. There are fire hydrants connected with external fire engines near the entrance and exit of the station to facilitate the support of external rescue forces.

1.1.4 The control system is reliable

There is an emergency alarm button on the train. In case of fire, explosion and other accidents, passengers can quickly press this button to inform the driver. When dealing with the accident, the driver will drive the train to the front station as far as possible, so that he can rely on the fire power of the station to carry out disaster relief (the train usually takes about 1.5 minutes to travel to the next station). If the train has stopped at the station, passengers can pull the red emergency mechanical unlocking handle above the door at the corresponding platform position and the green unlocking button on the screen door to open the door for evacuation (even if there is no power supply, the train door and screen door can be opened manually), so that passengers can't open the door like the Korean subway accident.

in case of fire, explosion and other accidents, the driver will inform the passengers to evacuate through the emergency evacuation doors at both ends of the train, and at the same time start the emergency lighting and ventilation system in the car (the emergency standby power supply in the car can ensure the lighting and air supply in the car for 45 minutes). Passengers can be evacuated in the direction of fresh air under the organization of staff.

Guangzhou Metro has a high degree of automation. When the train in the station catches fire, the smoke sensing system quickly transmits the information to the control center and starts the signal blocking system to prevent the adjacent train from entering the station. At the same time, each station also has the function of detaining cars, and the operation is simple. There are reliable smoke exhaust facilities in Guangzhou subway station, and the smoke exhaust capacity is far greater than the ability of fire to produce toxic gases. In the design of smoke exhaust, according to the principle of "people-oriented", the system can collect fire information within 2 seconds, and the equipment can be started in 2 minutes. After the smoke exhaust equipment is started, a large amount of fresh air flows in from the entrance and exit, and through reasonable airflow organization, the smoke is discharged from the ventilation shafts at both ends of the station, ensuring that passengers can always evacuate against the fresh air.

1.1.5 Two-way power supply system ensures foolproof

The equipment for providing important fire information and smoke exhaust in Guangzhou Metro adopts the first-class load, which is "double power supply and double circuit", and the facilities at both ends of the station are also independently set up for mutual backup. When one power supply loses power, the other power supply is automatically put into power supply immediately to ensure the reliable operation of smoke exhaust equipment. Even if the double-circuit power supply is completely interrupted, the station emergency power supply can still provide basic electricity such as guiding signs and emergency lighting for 1 hour to ensure foolproof.

1.1.6 Strict management system

Guangzhou Metro has strict management system, which can effectively prevent and control the occurrence of fire. Guangzhou Metro staff will start inspection of smoke exhaust equipment before operation every day to ensure the normal operation of the equipment. The company carries out paramilitary management on employees, and conducts corresponding fire drills regularly. The staff are proficient in various emergency handling skills, and have formulated a set of perfect accident emergency handling plans in operation practice.

1.2 Shanghai Metro

Shanghai Metro has two sets of automatic fire prevention facilities: two-level automatic monitoring system, one in the station and the other in the central control room; Automatic fire extinguishing and spraying systems, including water spraying and air spraying, can be adjusted according to different fire causes. There are fire hydrants, emergency lighting and alarm telephones in the tunnel. In the subway train compartment, the on-board fire extinguisher bracket was reformed, 256 sets of fire extinguishing equipment were added, and luminous indication signs were set in the eye-catching position in the compartment to indicate the access method, which was convenient for passengers to use in an emergency.

178 sets of gas masks have been distributed to 23 underground stations, and the subway tunnel is also equipped with special smoke exhaust devices. In case of fire, the accident fan system in the tunnel will be started to exhaust toxic smoke in the shortest time to prevent suffocation. In addition, if there is an accident in the train compartment and the door cannot be opened, the special "escape door" in front of the train head can be opened manually to evacuate the passenger flow. The underground station is equipped with emergency light evacuation signs and safety prohibition signs.

1.3 Decoration materials of Shenzhen Metro

1.3.1

All vehicles and stations in Shenzhen Metro are made of fire-proof materials certified by the Fire Bureau, and all vehicles' carriages, handrails, seats, equipment pipelines, station platforms, walls, ceilings and other materials are incombustible or flame retardant.

1.3.2 Automatic control and fire alarm system

The automatic control system and fire alarm system of Shenzhen Metro are the most advanced in the world at present. When an emergency happens, the alarm system can give an alarm reliably, accurately and quickly within a few seconds. After receiving the alarm signal, the automatic control system will automatically turn on and operate various emergency rescue equipment such as fans, water pumps, emergency lighting and gas fire extinguishing devices. If the circuit is interrupted, the battery will start the above rescue equipment, so there will be no situation that the door cannot be opened.

1.3.3 smoke control design

the station is designed with a fire prevention and smoke control zoning system, and several smoke storage areas are installed on the upper part of the ceiling of the station, and each smoke storage area is equipped with a smoke exhaust duct, which can quickly draw smoke and toxic gases in and out to prevent the spread of smoke fire.

1.3.4 Emergency evacuation system

The emergency evacuation system of Shenzhen Metro is perfect. When a fire breaks out, all gates and doors will automatically open to safety, and all elevators will travel in the same direction. The evacuation passage is spacious, which can ensure that all passengers and staff can be evacuated to safety within 6 minutes in an emergency. At the same time, Shenzhen Metro is designed to use software management system to prevent emergency fires. In the design, the possible fire situations of all stations and carriages are simulated into more than 1 fire situations and input into the computer system, and the computer system quickly starts the fire-fighting emergency evacuation system according to the actual situation.

1.3.5 Fire water supply system

The fire hydrant system of Shenzhen Metro is a wet system, with a circular pipe network, and its service scope is the lowest slope of the station and the adjacent area of the station (at the connecting passage). Fire fighting pipes are connected from urban water pipes, which are arranged in the lower part of the station hall and platform floor, as well as in sections and pedestrian passages, and fire fighting branch pipes are set according to the positions of fire hydrants. Setting spacing of fire hydrant box: 3m～4m on the station hall floor; The platform floor is 4m～5m; The equipment area and pedestrian passage of the station hall floor and platform floor are set as required.

a fire pump adapter is set on the water supply inlet pipe outside the station, and an outdoor low-pressure fire hydrant is set within 4m of the adapter.

1.4 Beijing subway

Beijing is the first city in China to build a subway. At that time, the first-line subway in Beijing was not built for the development of traffic in the city, but for the preparation for war in response to the international environment at that time. Therefore, its internal construction and design standards are far from meeting the current use requirements. The building structure of Beijing subway adopts reinforced concrete structure, with one fire hydrant every 1m in the first line subway and one in the second line from 3 m to 5 m. The machine room is equipped with an automatic fire extinguishing system, and all stations are equipped with portable fire extinguishers. Smoke control, ventilation and normal ventilation use one system. The station is equipped with emergency lighting, and the train is equipped with emergency broadcasting.

2 fire problems in China's subways

2.1 There are many hidden dangers in old subways

2.1.1 There are serious hidden dangers in electrical equipment

There are more than 5 substations in Beijing's first-and second-line subways, except for a few located on the ground, the rest are located at stations along the underground. In addition to power generation equipment, there are six 35kV substations in the underground power station which adopt oil-immersed transformers and oil-immersed arc suppression coils. Once the power station transformer or arc suppression coil bursts in fire, the oil will leak and overflow everywhere, and flow into the subway tunnel from the hoisting port or cable hole, which will directly endanger the safety of running vehicles and spread the fire. In addition, there is no fireproof partition between the hoisting opening of the transformer room and the tunnel, which makes the fire spread more easily.

2.1.2 Incorrect laying of wires and cables

On the cable brackets on both sides of some tunnels in Beijing Metro, cables of various voltage levels are jumbled together. As long as one wire catches fire, it will inevitably lead to a power outage accident of the whole system and expand the scope of the accident. In addition, some unprotected cables are directly laid behind the protective plate of the contact rail, or some are soaked in water, or even some cable heads are directly buried in cement without treatment. Most of these cables are made of PVC without flame retardant treatment, which will produce a lot of smoke and toxic gas in case of fire or short circuit, seriously endangering the lives of passengers and emergency personnel. In addition, underground rats are seriously damaged, and there have been many accidents in which rats bite the wires, resulting in short circuit of cables and burning of equipment.

2.1.3 Heavy fire load

There are 28 stations and 227 commercial service outlets in Beijing Metro Line 1 and Line 2, and more than 14, advertising carriers such as light boxes, drawing boards and wall stickers are set up in the station halls, platform halls, passages and carriages of each line. These facilities not only occupy the limited evacuation space, but also increase the fire load in the subway station and increase the possibility of fire.

2.1.4 Equipment overload

Electric equipment such as exhaust fans, air conditioners, escalators, communication signal controllers and lighting equipment in Beijing subway are likely to cause fires under long-term overload operation.

2.1.5 building houses without permission

most of the buildings in Beijing subway are non-combustible, but a considerable amount of combustible materials are used in the decoration of halls and rooms, and some important computer rooms, equipment rooms and duty rooms use wooden floors, parapets, ceilings and plastic foam sound-absorbing materials. Some temporary rooms were also built in the underground workshop to ensure the living needs of the staff. At the same time, subway workers use a lot of electrical equipment such as dehumidifiers, electric heaters and electric furnaces to pull wires privately, which increases the risk of fire.

2.1.6 The safety performance of electric buses is not high

There are 117 trains and 579 sections of electric buses in Beijing Metro, all of which are made of FRP. However, because our country has not formulated the detailed rules of fire protection grade for subway vehicles, the design of electric buses can only refer to the existing fire protection technical standards, and these technical standards are not completely suitable for the special requirements of subway vehicles, and the flame retardant performance of interior decoration materials is not high. In addition, the alarm communication device in the car and the door opening device in the accident state are equipped differently, which is not convenient for passengers and drivers to report the disaster or take corresponding measures.

2.1.7 Incomplete fire-fighting facilities

The fire-fighting equipment of Beijing Metro Lines 1 and 2 is very rudimentary. There are no automatic fire alarm system and automatic fire extinguishing facilities in the station platform and station hall. Although the subway station has a fire hydrant system, it is not well maintained. The subway fire pipe network in some stations is not connected with the municipal pipe network, and some fire hydrants are rusted and cannot be used. Evacuation signs in subway tunnels do not meet the requirements of "one for interval tunnels and evacuation passages every 1m" and "its height is 1 m ~ 1.2 m from the ground"; The emergency lighting did not meet the requirements of "every 2m or so in the evacuation passage and interval tunnel".

2.1.8 Poor ventilation and smoke exhaust facilities

There are 114 ventilation and smoke exhaust machines in various lines in Beijing. In case of fire accident, the normal exhaust system can be converted into smoke exhaust system, but the normal temperature of fans is limited to 8℃, and they do not have the ability to exhaust smoke quickly in a short time. In addition, there is no smoke-proof hanging wall at the stairs of the platform and the platform hall, and no fire and smoke prevention zones are divided.

The wind pavilion of Beijing subway is seriously occupied and blocked, which also poses a certain harm. There are 95 ground wind pavilions in the first and second subway lines, some of which are enclosed and some of which are partially blocked, which can not guarantee effective operation under high temperature and thick smoke, which is bound to cause great difficulties for the safe evacuation of personnel and fire fighting and rescue.

2.1.9 The safety evacuation capacity is seriously insufficient

The original designed daily passenger capacity of Beijing Metro is 3, passengers, and now the maximum daily passenger capacity has reached more than 2 million passengers, with the peak hour of 24, passengers, and the maximum number of stops during peak hours can reach 4,581 passengers, which seriously exceeds the design capacity. There are 215 entrances and exits in the design of Beijing subway. The width of exit stairs and evacuation passages in most subway stations can't reach the ability of "evacuating a train of passengers and passengers and staff waiting on the platform within 6 minutes in case of fire", and the rapid growth of passenger flow is underestimated. In particular, several stations in the west of the first line have only two exits, and once a fire breaks out, the evacuation capacity is obviously insufficient. Moreover, the walking distance of some platform evacuation passages is long, which seriously affects the evacuation speed.

2.2 The safety design of the equipment area is unreasonable

There are many lounges, offices and other non-working places in Beijing Metro, and its safety evacuation design cannot meet the requirements in terms of the number of exits and the safety distance. There is no safe exit in the equipment area of Shanghai Metro, so the evacuation of its staff has become a big hidden danger. Because the equipment rooms are small and messy, the use functions and fire properties of various houses are very different, and the management of various internal systems is complicated, which makes it very difficult to design fire safety. Taking a station of Guangzhou Metro as an example, there are 11 large and small ventilation and air conditioning duct systems in only one equipment management room area, as well as numerous power cable trays, communication cable trays and various large-diameter water pipes. Each system is also frequently staggered due to functional requirements. It is quite difficult to arrange these systems reasonably in a limited space, and how to do a good job in fire safety design is a problem worthy of attention.

2.3 it is difficult to grasp the smoke control and exhaust design of subway station

subway station is a very special building, should it be