Stand-alone alarms, fire-fighting robots, dry powder fire-fighting missiles...

Using technology to solve the problem of fire fighting in high-rise buildings

  ◎Our reporter Chen Xi

  Nowadays, super high-rise buildings with a height of more than 100 meters are very common, and fire fighting and rescue of high-rise buildings is a recognized worldwide problem in the field of fire protection.

The rescue of high-rise buildings is difficult not only because of the height, but also because of the complexity of the rescue of ordinary buildings.

  On September 16, a fire broke out in the China Telecom building in Furong District, Changsha City, Hunan Province. The video posted on the Internet showed thick smoke billowing at the scene, some items with fire falling down, and dozens of floors of buildings burned violently, which made people very worried.

  The telecommunications building where the fire broke out once became the first building in Changsha to exceed 200 meters at a height of 218 meters. However, this former "giant" also created obstacles to fire fighting.

According to data from the Fire and Rescue Bureau of my country's Ministry of Emergency Management, a total of 4,057 high-rise building fires were reported in 2021, resulting in 168 deaths, an increase of 22.6% over the previous year.

With the acceleration of urban development in my country, there are more and more high-rise and super high-rise buildings, and solving the problem of high-rise fire fighting and rescue has become a top priority.

  High-rise building fires are more difficult to fight than ordinary buildings

  In recent years, fire accidents in modern high-rise buildings have occurred frequently: from the "6.14" fire accident in the London apartment building, to the "8.4" fire accident in the Torch Tower in Dubai... In the face of the raging fire, even if the firefighters do their best, it is possible It is also difficult to prevent the tragedy from happening.

  "Generally speaking, residential buildings with a height of more than 10 floors and public buildings with a height of more than 24 meters are considered high-rise buildings. Nowadays, super high-rise buildings with a height of more than 100 meters are very common. Fire fighting and rescue of high-rise buildings is currently a recognized worldwide problem in the field of fire protection. "Liu Yunlong, chief of the Comprehensive Guidance Section of the Fire Rescue Detachment of Dongli District, Tianjin, introduced in an interview with a reporter from Science and Technology Daily that the rescue of high-rise buildings is difficult not only because of the height, but also much more complicated than the rescue of ordinary buildings.

  "Once there is a fire, it is extremely difficult to rescue from outside the building." Liu Yunlong said that in general, the main equipment for external rescue is the fire-fighting ladder truck, but the commonly used fire-fighting ladder is only about 50 meters and can only reach the height of 15 floors.

At present, the highest known fire ladder in China is 101 meters, and it can only reach about 35 floors at most.

The reason why the fire ladder should be "limited to the height" is mainly because the higher the height, the higher the requirements for the operation and the driving of the fire truck.

  "For high-rise and super-high-rise buildings, it is also difficult to put out fire outside the building. Because it is far away from the fire point inside the building, it is difficult to put out the fire, so the current high-rise building fire extinguishing mainly relies on 'internal attack', that is, it is necessary to Firefighters enter the building, relying on internal firefighting facilities or laying water belts along the stairs, etc., to continuously transport the fire extinguishing agent to the fire point for fire fighting." Liu Yunlong explained.

  These "black technologies" are good helpers for firefighters

  With the continuous advancement of science and technology, some "black technologies" have been applied to the firefighting and rescue of high-rise and super high-rise buildings, and have played a very good role.

  In terms of fire prevention, using the Internet of Things technology, some sensor probes in the building can be connected to the fire department. Once a fire occurs, these departments can receive a fire warning at the first time.

"At present, some areas in Tianjin have issued 'self-contained fire alarms' for the elderly living alone, which are connected to the mobile phone. When the alarm senses the smoke or the temperature in the surrounding environment exceeds a certain threshold, it will send an alarm to the children of the elderly living alone, so that the They can know the danger immediately." Liu Yunlong said.

  In terms of fire fighting, firefighters now have many "good helpers".

Firefighting robots can assist firefighters in a range of tasks in hazardous areas, such as fire fighting, equipment transportation, and more.

"This kind of robot is like a small tank. It travels on tracks. They carry water guns and can be connected to water hoses. Firefighters can control it from outside the fire scene to enter the fire scene to extinguish the fire." Liu Yunlong further said that even if there is an explosion on the scene, the firefighters will not will be injured, which greatly reduces the probability of firefighters being injured, so they are mostly used in large fires.

  In recent years, drones have also been widely used in high-rise building fire fighting.

When a high-rise building is on fire, drones can conduct reconnaissance on the fire spot.

"Especially when the fire point is very high and the smoke is heavy, the drone can accurately and quickly find the fire point, so that firefighters can put out the fire more targeted." Liu Yunlong said.

  In addition, there are some "black technologies" that are expected to become the "killer" for fire fighting and rescue in high-rise and super high-rise buildings.

  The "projection-type high-rise building dry powder fire truck" developed by No. 206 of the Second Research Institute of China Aerospace Science and Industry Corporation can use missile launch technology to launch fire-extinguishing missiles to high-rise buildings. Each shell has 3.6 kg of high-efficiency dry powder fire extinguishing agent.

The dry powder fire extinguishing agent will form a film on the surface of the combustible when it is heated, and the combustion must have oxygen. After the film is formed, it prevents the fire from continuing to react with the oxygen, and the fire cannot burn.

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  It's not just the floor height that makes it difficult to put out a fire

  The difficulties of fire fighting in high-rise buildings are mainly reflected in the following points.

  First of all, there are so many people that it is difficult to evacuate and rescue.

Super high-rise buildings have a large area of ​​use and various functions, which will inevitably bring a large number of people together.

Once a fire breaks out, the elevator will be disabled, and people will pour into the evacuation stairs, which will block the evacuation channel and seriously affect the speed of people's travel.

Therefore, the evacuation and rescue of a large number of people is the key problem that needs to be solved in the emergency rescue of super high-rise building fires.

  Secondly, the fire situation is complex and difficult to control.

In order to meet the requirements of functional diversity, each sub-section of a super high-rise building has its own decoration and decoration style, and there are a large number of combustible materials, which leads to a large fire load, and a large-scale fire can be formed in a very short time, making it difficult for rescuers to control.

From the perspective of fire spread, indoors, there are many vertical elevator shafts, cable shafts, and pipeline shafts. After a fire occurs, it is easy to form a "chimney" effect, causing smoke and fire to spread upwards rapidly; Smoke and fire can spread horizontally.

All these contributed to the rapid spread of the fire.

  Again, the building is too high, and it is difficult to supply fire extinguishing agents.

Whether the fire extinguishing agent can be delivered to the fire floor of the super high-rise building in a timely and uninterrupted manner and meet the flow required for fire fighting is directly related to the success or failure of the fire fighting battle.

  "In the entire super high-rise building fire, a variety of fire phenomena (explosion, flashover, flashback, fire and wind pressure, etc.) will occur at the same time, which seriously threatens the safety of the masses and rescuers, and brings great challenges to firefighting and rescue work. ” said Liu Yunlong, Chief of the Comprehensive Guidance Section of the Fire Rescue Detachment of Dongli District, Tianjin.

  Compared with the past, although the rescue equipment of the fire department has been greatly improved, it is better to prevent problems before they happen.

  First of all, in architectural design, it is necessary to strictly implement the fire protection specifications for architectural design: it is forbidden to use flammable and combustible materials as external thermal insulation materials for the exterior walls of high-rise civil buildings.

At the same time, in terms of house structure and facilities, it is necessary to set up fire isolation belts, install fixed fire protection facilities and ensure that they are complete and easy to use.

  Second, to establish a good fire early warning system.

To implement the main responsibility of fire protection, evacuation drills should be carried out on a regular basis; daily inspection and maintenance of fire protection facilities should be carried out on time, and hidden dangers of fire protection should be detected in time.