Live coverage of the Energy Storage Conference | Li Hongwei from Nanxiao: Integrated solution for lithium battery energy storage and fire protection

China Energy Storage Network News : The 12th China International Energy Storage Conference speech transcript is as follows:

Li Hongwei : Good afternoon, everyone! Let me introduce myself first. My name is Li Hongwei, and I am the former technical director of Nanjing Fire Equipment Co., Ltd. Because my position has changed, I am now in charge of the marketing department.

Today I am fortunate to come to the beautiful Hangzhou and share with you our Nanxiao’s fire protection solutions in the field of energy storage. I hope that after this PPT, you can have a better understanding of our Nanxiao, what kind of company we are, what plans we have made for energy storage projects in the past, and what services we can provide to you in the future.

My PPT consists of four parts, including an introduction to the company, the current status of the industry, some of our existing solutions, and some of our successful projects.

Nanjing Fire Equipment Co., Ltd. was established in 1958. I believe it has a long history in the fire protection industry, and it can be said to be one of the oldest companies. Our company was originally called Nanjing Fire Equipment Factory, so at the beginning, we were engaged in the production of fire protection industry, and at that time we only produced portable fire extinguishers. After more than 60 years of development, we have always been a leader in the fire protection industry, including many products that were first launched in China. I would like to emphasize here that in 2018, we began to enter the energy storage industry, because energy storage began to flourish and there was such a demand in the market, so we had already entered this market at that time to do some research and development, and we launched the second-generation lithium battery fire protection solution. What is the second generation? I will analyze it in detail later.

Nanxiao is also an old company with more than 60 years of history, so we have a relatively complete range of qualifications and certifications in the fire protection industry. First of all, the two certificates in the upper left corner should be familiar to everyone, which are the Class A design and Class I construction contracting certificates. These two certificates are the highest level of access in the fire protection industry. In addition, we have a nationally recognized laboratory, the CNAS laboratory, which will be discussed in detail later. Including high-tech enterprise certificates and some ISO certificates. Some of our products are UL and FM certified.

For the industry, we not only provide products, we provide a solution. This solution is based on, first of all, we have design, production, manufacturing, including sales teams, including installation, maintenance, and commissioning after R&D. The whole can be called a turnkey project. We have a professional team. In addition, we still emphasize the fire test center. This fire test center can play a role in both the early stage of R&D and the later stage of implementation. Just now, Director Huang of our Shanghai Institute of Fire Protection mentioned that, especially for the energy storage industry, when the national standards are not yet perfect, the standards also say that for energy storage fires, we must rely on a one-to-one construction and a physical fire model to conduct experiments. At this time, the importance and necessity of our laboratory are reflected.

In addition, smart cloud and the Internet of Things have been promoted recently in China and throughout the industry, and we also have corresponding platforms.

We have our own solution for energy storage, which has been verified to be reliable through our experiments. In addition, our product has obtained patents in many countries, including some certifications.

As an old fire-fighting manufacturing unit, we have a relatively complete range of products. Our main products are listed here, but in fact there are more than that, including portable fire extinguishers, gas water mist, foam, water products, electronic alarm products, and a full range of products can be provided.

It is used in many industries, from data centers, electricity, petroleum and petrochemicals, rail transit, marine, urban complexes, and energy storage projects. We have many application cases.

The second part is the current status of the industry. In fact, many colleagues, including competitors or peers, have already introduced it, so we will not repeat some of it. In fact, the most important aspects here are the lack of regulations. Director Huang of the Shanghai Fire Protection Research Institute also mentioned that there is no clear regulation to guide everyone on how to do energy storage fire protection. This may be a big challenge.

It is precisely because the standards are not clear that there are many products on the market. The experts mentioned earlier that some use heptafluoropropane, some use perfluorohexanone, some use water spray, and some use a combination of these. In fact, up to now, there may not be a completely effective product with particularly ideal effects. We are also constantly exploring, which is also a challenge.

We have listed some of the national standards and specifications that we can collect at present, including the country's requirements for the future development of energy storage, which Director Huang also mentioned in his PPT just now.

We just said that Nanxiao launched the second-generation solution. For the first generation, we talked about the general fire protection system, that is, in the energy storage, you often encounter a cabinet of heptafluoropropane. The reason for its placement at that time may be that the fire of energy storage was classified as an ordinary electrical fire. It may be set according to our national standard, which is the national standard 50370 for gases. Many experts have also said that heptafluoropropane alone is actually insufficient in extinguishing fires, especially in suppressing re-ignition. We have also discovered this problem through a large number of experimental studies. Therefore, it can only extinguish fires. It can extinguish a fire once, but it cannot suppress re-ignition, including the subsequent release of some flammable gases or even explosions.

Here is some information we have collected. I believe you have all seen it, especially the accident in Fengtai, Beijing two years ago, which promoted the entire country's attention to energy storage safety. Two firefighters were injured or killed, including one missing. This was a pretty serious incident.

Just now, we have discussed why batteries catch fire and explode. As you can see from the picture above, it is actually thermal runaway caused by battery failure. How does this thermal runaway happen? It may be mechanical damage, or it may be a defect inside the battery, or it may be due to overcharging, that is, the current or time of overcharging during charging. No matter which one it is, what happens in the end is thermal runaway of the battery. In layman's terms, it is a short circuit inside. After the short circuit, the current is very large, and heat will be released. At the same time, there is a flammable gas inside. When the heat accumulates to the ignition point, it will naturally burn or even explode. It is such a simple thing.

For us, we study the principle of why it gets out of control, so that we know what measures to adopt at what stage.

Let's take a look at our experimental capabilities. I have been emphasizing our nationally recognized fire laboratory. We have conducted a large number of fire extinguishing experiments in this laboratory since 2018. We compared different fire extinguishing agents, so there will be four videos later. I will show them to you. These are a few typical ones selected from the large number of experiments we have done. In fact, we have done a lot. You must have never seen a real battery overcharged. Its fire is in this state, in a jet-like shape, and the gas is ejected like this. This is a battery pack. In fact, there will be many battery packs in the container. Director Huang has a photo just now that you should be able to see. This video is a fire extinguishing experiment we did with pure high-pressure fine water mist. The final result is that it was extinguished, and there was no subsequent re-ignition.

We used a battery module to do this experiment. We first used HFC-227ea to extinguish the fire. These four videos are from four cameras, all of which are from the same battery module. We used a container to simulate an energy storage compartment, and we can see the thermal runaway of the battery, including the state after a combustion, including the state outside the box. This was the first time. 30 seconds, we sprayed HFC-227ea and 7 minutes later, it re-ignited, and the combustion was more intense than the first time. During this process, its flammable gas was continuously released. After another 30 seconds, we started high-pressure fine water mist to extinguish the fire. Finally, the fire was extinguished and there was no re-ignition.

In fact, our final solution is to use a combination of heptafluoropropane and fine water mist. For the energy storage cabin, heptafluoropropane is used to extinguish the fire of external electrical equipment, and high-pressure fine water mist is used to extinguish the fire with nozzles placed on each battery module. We chose such a combination solution.

This video shows a cluster-level battery fire we conducted. We also used fine water mist to conduct the experiment, and the fire was extinguished in the end.

The last experiment may be of concern to everyone. Everyone said that when I use fine water mist, it feels like water. Does it have any effect on my battery and BMS, which are all electrical devices? The last one is that we use fine water mist to cold spray the BMS and battery module. After the experiment, we took the battery pack to a special evaluation agency for charging and discharging, and to check the function and appearance. The final result is that there is no problem with these batteries. This experiment is a cold spray experiment on the equipment.