The safety alarm bell rings | The safety of power battery is not equal to the safety of new energy vehicles

Test

Experiment 1: After the heat is out of control, the people in the car have enough time to escape

At the open outdoor test site, the reporter saw two traditional fuel vehicles and one new energy test vehicle parked in three standard parking spaces. A data collection area is set 15 meters away from the test vehicle. This area is separated from the test area by solid walls, and the information such as the time of battery pack thermal runaway, the time of smoke, the time of open fire, the time of smoke entering the cab, and the time of flame entering the cab are collected respectively.

At 9:00 a.m., the experiment officially began. By simulating the battery thermal runaway of new energy vehicles, shoot and record the battery pack fire process and fire spread trend, and analyze the impact on vehicles near parking spaces and the overall flame spread trend.

The heating strip triggered the thermal runaway of the battery of the intermediate new energy test vehicle. At 9:09:52, the cell heating was started. At 9:19:33, the first smoke was emitted (the national standard requires more than five minutes, and the experiment shows that it has been nearly 10 minutes). Two temperature detectors of the first cell thermal runaway exceeded 1000 degrees centigrade, that is, the first and second temperature detectors failed, triggering the thermal runaway of the first cell, and the carbon monoxide value reached 10000 ppm. At 10:12:15, the second smoke was emitted, and the third temperature detector failed after exceeding the limit range of 1300 ℃, triggering the thermal runaway of the second cell, while the carbon monoxide value at this time was significantly lower than the first trigger point. Very little smoke enters the vehicle. From the experimental results, in the case of thermal runaway, the driver and passengers still have enough escape time.

Experiment 2: After a new energy vehicle catches fire, the fire extinguishing position is very important

The vehicle is ignited by an external fire, the flame spread trend is photographed and recorded, and the impact of the battery on the flame and the surrounding vehicles is analyzed. Monitor the burning process of the whole vehicle after the fire in real time, observe the time when the flame and smoke enter the cab, and record the temperature change of each part and the concentration change of toxic gas (CO) during the burning process of the whole vehicle.

At 13:40, the experiment began. At 13:44:30, smoke entered the passenger compartment. At 14:01:29, the rear side camera of the vehicle showed open fire entering the passenger compartment. In the experiment, the time from the ignition of the brazier to the thermal runaway of the battery was 40 minutes, and each detector was burnt out. A large amount of smoke entered the cab of the hole burned by the flame from the rear of the vehicle, and then a large amount of flame spread to the cab, the flame expanded, and the vehicle burned. The heavy rain did not stop at the scene, but it did not affect the fire in any way. The crackling sound and pungent smoke were constantly heard. The left rear wheel appeared first, followed by the right rear wheel and the right experimental vehicle.

According to the burning characteristics of new energy vehicles, the fire officers and fighters rescue on the spot. One firefighter wearing insulating clothing holds a detector to detect the temperature of the fire site and whether there is electricity leakage at all times. Four firefighters cool down through four point water guns. Two firefighters use the bottom sprinkler developed by the brigade to insert from the front of the vehicle to extinguish the fire at the bottom. Other firefighters use the car shifter to remove adjacent vehicles and expand the rescue space, The two firefighters then inserted the bottom sprinklers from the left and right sides, and the fire was quickly controlled.