"Burst! Spontaneous combustion of a new energy vehicle on a certain road"
"Another new energy vehicle, charging spontaneous combustion in underground garages"
The weather slowly warmed up, and such news began to pop up again.
Anyway, the comment area of the spontaneous combustion news of this type of tram has always been a daily "line-to-line" stage for netizens.
The oil truck party ate melons and watched the drama and sneered: "Oh, you have to buy a tram", the tram party began to pull all kinds of data in response: "The spontaneous combustion rate of oil trucks is not low, and the safety of the tram is better."
Fans of various new energy brands will also attack each other: "I don't need to click in, I know that it is ×× burned again" "×× brand will definitely not be on the news if it burns"...
Let's be fair, at present, there is no data to show that trams are necessarily more prone to fire than oil trucks.
According to the U.S. Bureau of Transportation Statistics and Auto Insurance EZ, electric vehicles have a fire probability of about 0.3%, which is lower than the 1.05% probability of gasoline vehicles.
The reason why the topic of the tram fire is high, and the neck brother feels that the more important reason is that compared with the oil truck, the scene of spontaneous combustion of the tram is quite terrifying, the fire spreads extremely quickly and is not easy to extinguish, and once the fire scene is difficult to control.
This is because lithium batteries release hydrogen and oxygen during combustion.
These two gases will continue to burn and release a lot of heat, further accelerating the battery combustion rate.
And not only is it difficult for us ordinary people to deal with tram fires, but even the existing fire protection system, seeing tram fires is one head two big.
Daily firefighters fighting fires are basically fire extinguishing agents + water two-plate axes, but if you use this set of things to extinguish the battery of the tram, it is basically Lin Daiyu plucking the willows upside down and scratching the itch?
Because the battery considers the safety of daily use, it will be specially protected in the waterproof shell, and as a result, the waterproof shell becomes a fire source protective shell, and the water cannot be poured at the fire point.
More often than not, firefighters water burning trams to cool them rather than extinguish them, but this water consumption is quite staggering.
According to the statistics of the US fire department, it is enough to use about 2-4 tons of water to extinguish a burning oil truck, and it takes 6-7 hours to water dozens of hundreds of tons of water to extinguish a burning Tesla.
Forget about wasting water, when so much water is watered, there will basically be nothing left of the car.
And extinguishing fires with dry powder and extinguishing agents such as carbon dioxide are still deflated.
Because the principle of these fire extinguishing agents is to find a way to isolate oxygen from the fire source, but as mentioned earlier, lithium battery combustion can release oxygen by itself, and there is no isolation at all.
Therefore, in many tram fire cases, the fire fighting method generally adopted by firefighters is "wait + prevention", wait is to wait for the battery to burn out, prevention is the further spread of the fire, which is why every time a new energy vehicle catches fire, it is rare to see a completely preserved disaster-stricken car, and finally there is at most a shelf left.
These operations are just expedient measures, and as the popularity of trams increases, the absolute number of tram fires will definitely increase, so we must find a way to better extinguish the tram fire.
For this reason, everyone is also eight immortals crossing the sea, each showing their own powers.
No, Denmark's emergency services have opened a brain hole, they have loaded the fire truck into a "big container" filled with water and some cooling materials.
Once a tram catches fire, they don't plan to water and extinguish the fire, but directly lift the car and throw it into the "container" for a 360-degree immersion.
I just want to say that the idea is very good, next time do not have to think about it, a fire car stunned into a fire + water truck.
There's also a method called "ColdCut Cobra," which sounds much more reliable.
It uses an ultra-high-pressure nozzle to spray out ultra-high-pressure water and corrosive materials, first extinguish the main open flame of the body, and then cut the battery pack with ultra-high pressure, directly cooling the battery inside and extinguishing the battery fire.
Although it may be quite difficult to extinguish the open flame of the body, at least there is no need to turn the train into a water tank, but this fire fighting speed is still quite laborious.
The fire safety company Rosenbauer has developed a special tram extinguishing system Battery Extinguisher System Technology (BEST).
It has an upward piercing spray gun, which can quickly pierce the battery's protective plate directly from the bottom without worrying about the raging fire on the body, and then fill the entire battery pack with water from the bottom up.
According to the developer, it takes about 40 minutes to successfully extinguish the fire with 2 tons of water, and they also said that this technology is especially suitable for use on high-speeds, after all, there is no fire hydrant on the highway, and it is difficult to pour tens of tons of water into the battery.
Nowadays, many fire agencies in foreign countries are ready to adopt this set of equipment.
But another problem has also arisen, fire trucks equipped with the BEST system are generally tall and large, high-speed outdoor can use this thing to extinguish fires, but to the underground parking lot, indoor charging piles, this kind of fire truck can not drive in at all.
And compared with high speed, these scenes are densely packed, and a car fire can easily cause a series of accidents, which is more dangerous.
This is not the British medicine and took out a new thing, they developed a six-wheel chassis extension Hiload based on the Toyota Hiracs pickup truck.
With this set of extensions, it can control the height of the fire truck body to 1850mm, which is enough to enter most underground parking lots.
Moreover, the modified car is equipped with a hydraulic power take-off (PTO), which can power the water pump for fire extinguishing.
At the same time, the body also carries an Atenta electric vehicle fire extinguishing system specially supplied for tram fire.
In addition to watering and extinguishing the fire, this system also incorporates the exclusive fire extinguishing solution of the electric vehicle in front, which can quickly cut the battery case and fill it with a special battery fire extinguishing agent to extinguish the fire.
During the entire rescue and extinguishing process, the battery temperature will be monitored continuously to prevent the battery from heating up and causing secondary combustion.
In general, the old problem of train fire is really difficult to solve.
Everyone has thought of a lot of problem-solving ideas, but it seems that it is only in the trial stage after all, and the current various solutions still have many shortcomings in terms of cost, operation and landing.
In the final analysis, the fire prevention and extinguishing of trams still require the joint efforts of manufacturers and fire departments.