What if the electric car is on fire? After reading this article, you may be able to save lives.
First of all, an effective way to control the fire is to effectively cool the battery and avoid the thermal runaway and the spread of thermal runaway under continuous high temperatures.
Lithium Grid News: Another new energy car fire incident: From the media, McCormack sent a message on Twitter on Friday night, "Last week (2018, 06, 15), my husband and his car in Los Angeles There was a fire on the street." She released a video in which the car parked on the side of the road, with flames and smoke coming out from below. She wrote. “In the traffic on Santa Monica Street, there was no traffic accident (referring to the collision accident).” “Thank you for the kind couple, they stopped him and let him park to stop...”.
First of all, this car that is on fire is the model S of tesla. From the vehicle itself, safety design measures were taken. So, a spokeswoman for Tesla said in an email, "Because of our battery structure, the cabin of the vehicle is completely immune to fire." How to read is like advertising, the same style of speech as Elon Musk.
Secondly, from the description of Twitter, the driver’s concern about family safety is reflected more deeply. “Thank God, my three little girls are not with him.”
Don't dare to agree with tesla security "10 times" algorithm
Can not use commercial thinking to appease the lives of users. We often see that when a new energy vehicle accident occurs, especially the spokesperson of tesla, on the one hand, "we are investigating the cause of the accident", and at the same time, we will see it in different places, Tesla Motors cited According to data from the National Fire Protection Association and the US Federal Highway Administration, it is ten times safer than fuel vehicles.
As far as the vehicle itself is concerned, fuel vehicles and new energy vehicles are very different in themselves: the number of sales, the frequency of use, and the environment in which they are used cannot be compared on a platform. It can't be because of the commonality of transportation, regardless of the length of time the product is launched, and cannot be compared with simple probability or other data. Users who face new technologies, new products, and crabs should have their own standards. From the accident itself, for the injured owner, it is 100% probability.
In the face of a fire accident that cannot be eliminated, the state, social organizations and enterprises need to unite as
Let us first look at the practice of the United States. In the case of traffic emergency rescue, whether it is technology or science, the United States is in the forefront and worth learning and learning. The American Fire Protection Association (NFPA) As early as 2010, the American Fire Protection Association launched online training and teaching of new energy security and received financial support from the US Department of Energy. At the same time, its joint vehicle companies carry out online training on rescue technologies for different models.
The safety of new energy is not entirely a problem that can be completely eliminated by the vehicle itself. Emergency rescue is also a solution. The extensive science is also a solution. How to do emergency rescue of new energy vehicles is also a measure and factor to ensure the safety of new energy.
New energy vehicles are developing at a high speed, and transportation and rescue needs to be followed up simultaneously.
Nowadays, new energy vehicles are becoming more and more common on the roads everywhere. Security issues have also become more prominent and unavoidable. Our country is the main market for new energy vehicle consumption. Solving the security problem is an urgent issue. At present, users' concerns about new energy vehicle technology and battery quality are more interpreted as concerns about driving range and function. In fact, faint security concerns are the key. The user is not an experimental product. We can understand what it is like from the worry of "thank you, the child is not in the car"! For the practitioners, it is a safe commitment and a heavy responsibility to the society.
Some people may think that we have a lot of regulations and many documents, and manufacturers have a lot of suggestions. Personally, these are far from solving the problem. It is important to understand the correct understanding of the entire consumer group and society, and to understand how new energy vehicles and their batteries are going. Second, take effective measures based on correct understanding. This is the complete consumer chain.
Know lithium-ion batteries : it’s harder to put out a fire
1, battery diagnosis and real-time monitoring also have links beyond the reach of the whip
Lithium-ion batteries used in new energy vehicles have their own particularities. It is mainly the conversion process of chemical energy to electrical energy. Chemical products are often very sensitive to temperature. On the one hand, the temperature collection of the battery system can not do the internal collection of the battery core; on the other hand, one or more collection points of one battery core is unrealistic, which will lead to the huge and complicated hardware of the acquisition and management system. At the same time, very many sensors will also bring difficulties to system layout, cost and reliability. The conventional temperature acquisition management system is mainly for module level or system level. For high-quality batteries with very good processability and consistency, limited temperature collection is completely sufficient. For example, LEAF's battery system (2010 version) has only four points of temperature acquisition. However, it is dangerous for batteries with poor consistency and poor process control. The temperature difference of the cell body, the difference between the individual cells is difficult to be reflected by the temperature sensor. This is a big risk. Therefore, the use of buses, especially buses for public transportation, and high-quality battery selection and application are very important and important.
2. When an accident occurs, time is life (immediacy of monitoring)
The above point, when it comes to temperature acquisition, there is still a bit of regret: that is, the temperature point collection, can not penetrate into the inside of the cell, in the initial stage of micro-short circuit or heat change, the outer surface of the cell or the ambient temperature point is collected, also exists The time difference of heat conduction. At this time, Qiaqi is the most precious time. The battery is different from the gasoline of the fuel cell , and it is on fire. Collision or internal short-circuit faults occur, from short-circuit, smoke, true to burning, and more violent deflagration before the thermal runaway occurs. Let's briefly enumerate the concept of failure time in the case of thermal runaway of the cell: LFP can be delayed to 10 minutes from overheating to fire, which is a valuable escape time. Therefore, the use of LFP batteries in the previous mentioned bus is technically justified. And the ternary lithium-ion battery, the failure time is much shorter. It only takes a few seconds to catch fire to deflagration. Therefore, the immediacy and accuracy of battery management system fault detection is very important. I suspect that Zhuhai Yinlong insists that lithium titanate battery is applied to the bus, mainly from safety considerations. Despite the sacrifice of energy density , consumer life is more meaningful.
3. Lithium-ion battery electrolyte is infiltrated, not dry, and there is also a risk of leakage.
Why do you mention the electrolyte of a lithium-ion battery? In fact, the main flammable substance is the electrolyte. Under normal working conditions, the electrolyte is constantly "inhaled" and "spit" by the positive and negative electrodes (convenient to understand, in fact, lithium ions shuttle between the positive and negative electrodes), the electrolyte is at a lower temperature of 175 ° C ~ 185 ° C It will be decomposed in large quantities, not only releasing toxic substances, but also certain flammability. Therefore, Japanese researchers have been studying fire-proof and explosion-proof electrolytes.
The leakage of the electrolyte must help the degree of combustion in the event of an accident. Among the three batteries of cylindrical, square, and soft-packed lithium ions, the risk of leakage of the soft-pack battery is greater.
4, lithium-ion battery fire, the first is to control the thermal runaway by cooling
In the initial new energy fire, it was completed according to the normal fire fighting operation process. More often, it is a type of high-voltage electrical fire rescue, considering high-voltage electrical damage. However, lithium-ion batteries have their chemical specificities and require more targeted measures. First of all, an effective way to control the fire is to effectively cool the battery and avoid the thermal runaway and the spread of thermal runaway under continuous high temperatures. Therefore, in T/CIAPS 0002-2017 "Lithium-Ion Battery Enterprise Safety Production Specification" 5.6.3, "The fire can be extinguished with a common fire extinguishing agent, and water is the most effective fire extinguishing agent for lithium-ion batteries." First, it is clean water, and it is also necessary to consider the conductivity hazard of electrolyte water.
However, in the state in which the vehicle battery is on fire, the battery is sealed in the battery case, and it is difficult to directly act on the battery through the clean water, and the battery case is also mostly under the chassis. It brings certain difficulties to the rescue. Therefore, when designing the chassis and the cover of the battery case, TESLA first considers the application of flame retardant materials to isolate or delay the fatal damage of the battery system to the passenger compartment.
Regulations cannot replace social extensive training and science
Although the promotion of new energy vehicles has been around for some years, it is still very short-lived in the history of automobile development; it is still a new application. From the constant maturity of technology to the general acceptance of users, it is not a short time to complete.
As early as December 26, 2016, the Fire Department of the Ministry of Public Security issued a notice to the fire brigades of all provinces, autonomous regions, and municipalities directly under the Central Government on the issuance of fire-fighting rescue procedures for new energy vehicles and fire-fighting safety points for the production and storage of lithium batteries: “Requirements to strengthen New energy vehicle fire fighting and rescue preparation work, research and crack the lithium battery production, storage and use of fire fighting problems, the Ministry of Public Security Fire Department organized 23 new energy vehicles and lithium battery production enterprises concentrated provincial, municipal, public security firefighting forces launched a special project Investigated and organized the "New Energy Vehicle Fire Fighting Regulations", "New Energy Vehicle Traffic Accident Disposal Regulations" and "Safety Points for Fire Fighting in Lithium Battery Production Storage and Use Places."
However, my understanding, the regulations are more and more perfect, and it is also a paper thing. More important is the widespread recognition of society. This requires training and promotion of relevant knowledge. I think the United States is doing very well in this regard. Through online training, through video demonstrations, through cooperation with OEMs and so on.
1. What if my car is on fire? NFPA recommends that drivers follow these three steps:
b) If possible, lean back.
c) Turn off the car. Go out.
d) Be at 100 feet from the vehicle while paying attention to traffic safety.
e) Call 119 for help.
f) Do not put out the fire yourself.
2. Utilize the advantages of network communication to achieve universalization, unification and standardization across the country.
From the US NFPA training courseware, you can see that it is very complete and operability. Online demonstrations, specific action guides to future training programs are all very standard. Synchronization has established numerous partnerships with car manufacturers to facilitate the interaction of information and technology. Personally, this kind of training is meaningful and operability is very strong, and can achieve the purpose of accident rescue.
Since the accident cannot be completely avoided, it is also meaningful to reduce the probability and reduce the casualties. Because our attitude is correct. Human life requires maximum respect. This point, I respect Dong Mingzhu's consideration.
If you do not solve the user's concerns, it will restrict the development of the new energy industry.
People are afraid of new energy accidents, especially on fire. How to take measures to let consumers put down the burden is not only a "safe ten times" calculation can solve. Going back to the question at the beginning of the article, objectively speaking, tesla has made a lot of efforts in terms of security. The details of security design can be seen in a lot. It is worth learning in many places. But it is still on fire, and the US rescue is also in place, but there are still casualties. We should think like this, if we don't do it, it might be even worse. It can be seen that the revolution in transportation and the development of new energy are not all smooth and require more efforts. Let the whole society pay attention to it, and our engineering and technical personnel must also take up this responsibility!