Anhui Zhongke Zhonghuan Liu Zhi: Thermal runaway warning and fire protection system for electrochemical energy storage power plants
Release Date:2020-08-27 Source: View count:731
North Star Energy Storage Network News: How to improve the safety of battery cells themselves is the most fundamental problem to solve the entire battery industry, including the energy storage industry. Due to current technological development issues, we have to use some passive protection technologies to solve the related problems of early detection, early warning, and later protection.
——Liu Zhi, Vice President of the Third Division of Anhui Zhongke Zhonghuan Defense Equipment Technology Co., Ltd
On August 26-28, 2020, under the guidance of China Energy Research Association, Zhongguancun Management Committee and Zhongguancun Science City Management Committee, the "Ninth Energy Storage International Summit and Exhibition" was held in Beijing jointly sponsored by the Energy Storage Special Committee of China Energy Research Association, Zhongguancun Energy Storage Industry Technology Alliance and the Institute of Engineering Thermophysics of the Chinese Academy of Sciences. The summit focuses on the theme of "Gathering the trend of energy storage for ten years, creating new opportunities for the 14th Five Year Plan industry", and holds a commemorative forum for the tenth year of the Energy Storage Alliance at the same time. The North Star Energy Storage Network and the North Star Power APP will broadcast the entire summit live.
At the "Energy Storage Innovation Forum" held on August 26th, Liu Zhi, Vice President of the Third Division of Anhui Zhongke Zhonghuan Defense Equipment Technology Co., Ltd., shared a report entitled "Thermal runaway warning and fire protection system for electrochemical energy storage power plants".
Liu Zhi, Vice President of the Third Division of Anhui Zhongke Zhonghuan Defense Equipment Technology Co., Ltd
Liu Zhi: Good afternoon everyone, it's my pleasure to introduce the thermal runaway system of electrochemical energy storage power plants. With the development of the industry, whether it's new energy vehicles or energy storage, they have been developing all along. However, the serious challenge we face is the safety of lithium batteries. You often see related reports on your social media, including videos from South Korea and the United States, which are quite shocking. Next, we will talk about lithium battery safety, which refers to the inherent safety of lithium batteries. How to improve the safety of battery cells themselves is also the fundamental problem to solve the entire battery industry, including energy storage. Due to the current technological development issues, we have to use passive protection to carry out relevant early detection, early warning, and later protection.
Thermal runaway of batteries can generate a large amount of heat, which poses a threat to the safety of the entire battery system. At the same time, a large amount of smoke is also generated, and the content of the smoke is very complex, including a large amount of carbon monoxide gas and organic matter gas. By using a large amount of experimental data and thermal runaway models for corresponding simulations, we can achieve early warning through various environmental parameters. Among them, several core parameter values are detected. The first is temperature, which is different from BMS temperature detection. The thermal runaway situation of lithium batteries is judged by the change in ambient temperature and absolute temperature value. The second is smoke parameters, which use non photoelectric smoke sensors to improve the sensitivity of the entire smoke detection. The third is carbon monoxide gas, which is a representative gas in the entire thermal runaway process. The concentration of carbon monoxide gas in the atmosphere is very low. In fact, during the combustion process of the battery, carbon monoxide with a concentration of more than 190 PPBM is produced. As the core parameter value of the entire thermal runaway warning, VOC value is also the core of early detection. Once the battery thermal runaway causes the pressure relief valve to open, there will definitely be a large amount of electrolyte leakage, and the evaporated electrolyte will fill the entire PACK box. Finally, humidity. In the automotive field, vehicles may involve some level of protection. If the humidity is too high due to aging, vibration, or other reasons, it can also pose a safety hazard to the battery.
When it comes to protection, you may want to compare some commonly used fire extinguishing agents on the market to see if they can handle thermal runaway of lithium batteries. Firstly, dry powder and carbon dioxide are known for their fire extinguishing properties. Dry powder achieves suffocation through a covering method, extinguishing the entire fire. For electrochemical internal combustion internal heat fires, the cooling effect is limited, and in real engineering cases, it is impossible to have a large amount of dry powder. Secondly, carbon dioxide and nitrogen are the same fire extinguishing principles. However, it is difficult to truly achieve fire extinguishing by isolating oxygen without taking away heat. The third one is water-based fire extinguishers. Water is a widely recognized fire extinguisher with several advantages. Firstly, it is very cheap and easy to obtain. Secondly, it has excellent cooling and extinguishing performance for this type of fire. Returning to real life, whether it's in car or energy storage, it's impossible to throw the entire car into the water. Large scale energy storage systems are expensive and complex, and a large amount of water can easily cause insulation failure, leading to serious secondary disasters. The thermal runaway of the battery itself is not simultaneous thermal runaway of the entire container, but slowly spreading from a single battery cell to the entire system. If water is used, it will cause significant losses to the entire system.
At present, heptafluoropropane, which is widely used in the field of energy storage, is effective in preventing physical fires in batteries, but it cannot lower the temperature. At the same time, because it is a gas storage device, once the gas is turned on, it will flood the entire room, but it has no effect on subsequent cooling and anti re ignition. Compared with the perfluorohexane system, which is an efficient, environmentally friendly, and continuously cooling friendly fire extinguishing agent, it can absorb a large amount of heat and cool down the entire PACK box. The second dielectric strength is 110 kV, which will not cause the entire system to malfunction due to water or aerosol spraying. At the same time, it is a liquid and does not require high-pressure storage. Non pressure storage and transportation bring great convenience to subsequent use.
In order to verify its continuous cooling characteristics, we stacked two battery cells together and induced thermal runaway through thermal runaway and automatic heating. There are two nozzles inside the box, which are connected to our perfluorohexane protection equipment. The initial experiment did not use any means to cool down, resulting in a natural cooling state. It can be seen that the cooling trend and rate are relatively slow. In the second experiment, with perfluorohexane present, after the temperature rises, thermal runaway occurs, and perfluorohexane spraying is implemented, resulting in a downward trend. After stopping spraying, the temperature will continue to rise, which will affect the second battery cell and the third battery cell, leading to a decrease in temperature. The gradual development of thermal runaway into system thermal diffusion is a serious problem, which can be addressed through point spraying, Releasing a limited amount of medication at different times to achieve an ideal state, stopping thermal runaway in a relatively stable manner, and extending the control time and average temperature.
At this time, our star product is also the fourth generation lithium battery detection and warning device, which is currently used in vehicles and energy storage. It is equipped with four sensors including carbon monoxide, temperature, smoke, and VOC, and has a small size and numerous interfaces that can automatically start. The first function is fire suppression, the second is point spray function, the third is one click start stop, and the fourth is secondary fine water mist suppression function. When the system detects thermal runaway, it first sprays perfluorohexane to prevent and control cooling without causing secondary damage to other cells. If there is still a high fire risk at this time, it can be manually started to spray different chemicals from the same host and pipeline. This is the ultimate backup solution we provide. It has the function of switching between main and backup power sources and self checking, with no pressure storage. At the same time, it can achieve internal circulation through the internal pump group. Self checking work does not require disassembly or factory monitoring, which is also the biggest advantage of the equipment.
That's all for today's sharing, thank you all.
(Transferred from the North Star Energy Storage Network)
North Star Energy Storage Network News: How to improve the safety of battery cells themselves is the most fundamental problem to solve the entire battery industry, including the energy storage industry. Due to current technological development issues, we have to use some passive protection technologies to solve the related problems of early detection, early warning, and later protection.
——Liu Zhi, Vice President of the Third Division of Anhui Zhongke Zhonghuan Defense Equipment Technology Co., Ltd
On August 26-28, 2020, under the guidance of China Energy Research Association, Zhongguancun Management Committee and Zhongguancun Science City Management Committee, the "Ninth Energy Storage International Summit and Exhibition" was held in Beijing jointly sponsored by the Energy Storage Special Committee of China Energy Research Association, Zhongguancun Energy Storage Industry Technology Alliance and the Institute of Engineering Thermophysics of the Chinese Academy of Sciences. The summit focuses on the theme of "Gathering the trend of energy storage for ten years, creating new opportunities for the 14th Five Year Plan industry", and holds a commemorative forum for the tenth year of the Energy Storage Alliance at the same time. The North Star Energy Storage Network and the North Star Power APP will broadcast the entire summit live.
At the "Energy Storage Innovation Forum" held on August 26th, Liu Zhi, Vice President of the Third Division of Anhui Zhongke Zhonghuan Defense Equipment Technology Co., Ltd., shared a report entitled "Thermal runaway warning and fire protection system for electrochemical energy storage power plants".
Liu Zhi, Vice President of the Third Division of Anhui Zhongke Zhonghuan Defense Equipment Technology Co., Ltd
Liu Zhi: Good afternoon everyone, it's my pleasure to introduce the thermal runaway system of electrochemical energy storage power plants. With the development of the industry, whether it's new energy vehicles or energy storage, they have been developing all along. However, the serious challenge we face is the safety of lithium batteries. You often see related reports on your social media, including videos from South Korea and the United States, which are quite shocking. Next, we will talk about lithium battery safety, which refers to the inherent safety of lithium batteries. How to improve the safety of battery cells themselves is also the fundamental problem to solve the entire battery industry, including energy storage. Due to the current technological development issues, we have to use passive protection to carry out relevant early detection, early warning, and later protection.
Thermal runaway of batteries can generate a large amount of heat, which poses a threat to the safety of the entire battery system. At the same time, a large amount of smoke is also generated, and the content of the smoke is very complex, including a large amount of carbon monoxide gas and organic matter gas. By using a large amount of experimental data and thermal runaway models for corresponding simulations, we can achieve early warning through various environmental parameters. Among them, several core parameter values are detected. The first is temperature, which is different from BMS temperature detection. The thermal runaway situation of lithium batteries is judged by the change in ambient temperature and absolute temperature value. The second is smoke parameters, which use non photoelectric smoke sensors to improve the sensitivity of the entire smoke detection. The third is carbon monoxide gas, which is a representative gas in the entire thermal runaway process. The concentration of carbon monoxide gas in the atmosphere is very low. In fact, during the combustion process of the battery, carbon monoxide with a concentration of more than 190 PPBM is produced. As the core parameter value of the entire thermal runaway warning, VOC value is also the core of early detection. Once the battery thermal runaway causes the pressure relief valve to open, there will definitely be a large amount of electrolyte leakage, and the evaporated electrolyte will fill the entire PACK box. Finally, humidity. In the automotive field, vehicles may involve some level of protection. If the humidity is too high due to aging, vibration, or other reasons, it can also pose a safety hazard to the battery.
When it comes to protection, you may want to compare some commonly used fire extinguishing agents on the market to see if they can handle thermal runaway of lithium batteries. Firstly, dry powder and carbon dioxide are known for their fire extinguishing properties. Dry powder achieves suffocation through a covering method, extinguishing the entire fire. For electrochemical internal combustion internal heat fires, the cooling effect is limited, and in real engineering cases, it is impossible to have a large amount of dry powder. Secondly, carbon dioxide and nitrogen are the same fire extinguishing principles. However, it is difficult to truly achieve fire extinguishing by isolating oxygen without taking away heat. The third one is water-based fire extinguishers. Water is a widely recognized fire extinguisher with several advantages. Firstly, it is very cheap and easy to obtain. Secondly, it has excellent cooling and extinguishing performance for this type of fire. Returning to real life, whether it's in car or energy storage, it's impossible to throw the entire car into the water. Large scale energy storage systems are expensive and complex, and a large amount of water can easily cause insulation failure, leading to serious secondary disasters. The thermal runaway of the battery itself is not simultaneous thermal runaway of the entire container, but slowly spreading from a single battery cell to the entire system. If water is used, it will cause significant losses to the entire system.
At present, heptafluoropropane, which is widely used in the field of energy storage, is effective in preventing physical fires in batteries, but it cannot lower the temperature. At the same time, because it is a gas storage device, once the gas is turned on, it will flood the entire room, but it has no effect on subsequent cooling and anti re ignition. Compared with the perfluorohexane system, which is an efficient, environmentally friendly, and continuously cooling friendly fire extinguishing agent, it can absorb a large amount of heat and cool down the entire PACK box. The second dielectric strength is 110 kV, which will not cause the entire system to malfunction due to water or aerosol spraying. At the same time, it is a liquid and does not require high-pressure storage. Non pressure storage and transportation bring great convenience to subsequent use.
In order to verify its continuous cooling characteristics, we stacked two battery cells together and induced thermal runaway through thermal runaway and automatic heating. There are two nozzles inside the box, which are connected to our perfluorohexane protection equipment. The initial experiment did not use any means to cool down, resulting in a natural cooling state. It can be seen that the cooling trend and rate are relatively slow. In the second experiment, with perfluorohexane present, after the temperature rises, thermal runaway occurs, and perfluorohexane spraying is implemented, resulting in a downward trend. After stopping spraying, the temperature will continue to rise, which will affect the second battery cell and the third battery cell, leading to a decrease in temperature. The gradual development of thermal runaway into system thermal diffusion is a serious problem, which can be addressed through point spraying, Releasing a limited amount of medication at different times to achieve an ideal state, stopping thermal runaway in a relatively stable manner, and extending the control time and average temperature.
At this time, our star product is also the fourth generation lithium battery detection and warning device, which is currently used in vehicles and energy storage. It is equipped with four sensors including carbon monoxide, temperature, smoke, and VOC, and has a small size and numerous interfaces that can automatically start. The first function is fire suppression, the second is point spray function, the third is one click start stop, and the fourth is secondary fine water mist suppression function. When the system detects thermal runaway, it first sprays perfluorohexane to prevent and control cooling without causing secondary damage to other cells. If there is still a high fire risk at this time, it can be manually started to spray different chemicals from the same host and pipeline. This is the ultimate backup solution we provide. It has the function of switching between main and backup power sources and self checking, with no pressure storage. At the same time, it can achieve internal circulation through the internal pump group. Self checking work does not require disassembly or factory monitoring, which is also the biggest advantage of the equipment.
That's all for today's sharing, thank you all.
(Transferred from the North Star Energy Storage Network)
