Introduction of electric vehicle lithium battery impact test

How big is the fire hazard of the “five-class car”? Yesterday morning, the Guangzhou Municipal Public Security Bureau fire brigade, trafficspecial detachment and Sun Yat-Sen University Fire Science and Technology Key Laboratory and Ping an Guangzhou Volunteer Service Corps conducted an electric vehicle fire safety hazard demonstration experiment in an abandoned building in Tianhe. The experimental scene of the fire caused by the burning of electric vehicles on the spot and the explosion of the battery was shocking, which made people realize the power of the hazards caused by the fire hazards of the “five-class car”.

[Experiment 1] Electric vehicle caused fire

The deadly gas in the stairwell was filled with the entire building.

At about 10:30 in the morning yesterday, a four-storey abandoned building in Tianhe, Guangzhou, was blazing and smoke, and the "culprit" of this experimental "fire" was actually three electric cars in the stairwell.

At 10:22, the experimenter ignited three electric vehicles. In just a few minutes, the stairwell of the building was soaring and the smoke was rolling. After 5 minutes, the highest temperature measured by the experimenter at about 30 cm above the electric car reached 1079.5 degrees Celsius. “After 6 minutes and a half after the fire, we placed a device for measuring the concentration of carbon monoxide on the top floor of the building, the so-called safest place. The result showed that the concentration of carbon monoxide was 772 ppm, and in a situation of 600 ppm of carbon monoxide, it would die in a few minutes. That is to say, this fire caused by the burning of electric vehicles, even if there is no fire in other parts of the house, no area is safe.” Dr. Mo Shanjun, Ph.D., Key Laboratory of Fire Science and Technology, Sun Yat-sen University, said.

The experimenter placed a small hamster on each floor. After the experiment, the staff found that the hamsters on all floors had no survival.

When firefighting, firefighters use household fire-extinguishing bullets and fire extinguishers to extinguish the fire. It is not effective at all. It is a last resort. The giant water pipes of the fire-fighting vehicles are used to extinguish the fire. Thespecial officer of the Municipal Public Security Bureau fire detachment Jin Yuhang pointed out that the experiment was carried out by combustion. In reality the electric vehicle fires to achieve the "spontaneous ignition point", so the burning speed will be faster.

[Experiment 2] Electric vehicle lithium battery hazard

A battery is shocked and exploded

The second experiment was about a lithium battery for an electric car. I saw the experimenter randomly removed several lithium batteries on some old electric vehicles. "These lithium batteries are made up of multiple lithium battery packs. I am worried that the power of the site is too great. We will select one of the battery components to do the experiment."

I saw the experiment staff put a finger-sized lithium battery on the test bench and hit it with a one-kilogram object falling above about one meter high. The small lithium battery first smoked, then “嘭” An explosion, the protective box was blown open a hole, and the scene also caused the invention of fire.

"This is just a battery component. If it is the battery of the entire electric vehicle, the power of the explosion caused by the impact can be imagined!" the experimenter explained.

【status quo】

Electric vehicles become a new cause of fire in recent years

Electric vehicles have become a new cause of fire in recent years due to poor quality and unreasonable design. According to incomplete statistics, since 2011, there have been more than 250 electric vehicle fires in Guangzhou, resulting in 16 deaths and 25 injuries, and direct economic losses of nearly 6 million yuan. This year, five people in Guangzhou died of fires caused by electric vehicles. In the other three people, the electric vehicles were fuel-burning agents and “accomplice”. The death toll accounted for about half of the total number of fire deaths in 2016.

It is worth noting that most of the more than 250 cases of electric vehicle fires occurred between 20:00 and 8:00, accounting for 72% of the number of electric vehicle fires; the high-incidence area of electric vehicles was residential, accounting for 55% of the total. Followed by repair shops and garages; electric vehicle fires are mostly caused by battery failures, accounting for 49% of the main reasons, followed by line short circuit and power line failure; electric vehicle fire incentives are mostly caused by electrical fires, accounting for all incentives 85 %, other incentives are maintenance work and legacy fire.

In addition, the administrative areas where Guangzhou's electric vehicle fires are high are Baiyun District and Zengcheng District, accounting for 14.2% and 10.4% of the total number of electric vehicle fires, respectively.

Electric vehicle fire occurrence time

Between 20:00 and 8:00, accounting for 72% of the total

Electric vehicle fire high incidence area

Housing accounts for 55% of the total

Reminder

Not at the stairs or at the door

"Now many neighborhoods put electric cars on the first floor stairs or at the door of the house. It is actually quite dangerous. Once burned, it is equivalent to sealing the escape route." Mo Shanjun reminded that electric cars should not be placed on the stairs. Or at the door, lithium batteries should not be overcharged. "In fact, our mobile phones and charging treasures are the same, when using lithium batteries, don't hit them first. Second, don't overcharge. Many people are always plugged in while sleeping. It is actually very Dangerous because the lithium battery is used for a long time, once the charging time is too long, it may spontaneously ignite or explode due to internal circuit short circuit."

Appeal

The public does not want to ride the "five cars"

Guangzhou trafficspecial appealed that electric vehicles are endangered. At present, Guangzhou is legislating to regulate the management of electric vehicles. It is hoped that the public will abide by the regulations and not drive the "five-class vehicles." For illegal drivers who use "five-class vehicles" illegal vehicles, the Guangzhouspecial's acts of performing official duties in accordance with the law are protected by law, any unreasonable trouble, malicious obstruction or even violent means obstructing thespecial to perform official duties according to law, the public security organs will pursue their legal responsibilities according to law. Never tolerate.

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