Tips-and-methods-of-lithium-battery-fire-suppression

Tips and methods of lithium battery fire suppression

Generally speaking, li ion battery safety problems are characterized by combustion and even explosion. The root cause of these problems lies in the thermal runaway inside the battery, in addition, lithium-ion batteries may also be affected by some external factors occurring safety problems, such as overcharging, ignition sources, extrusion, puncture, short circuit and so on.

According to statistics, in the past years, 68% of the electric vehicle lithium-ion battery fire accidents were caused by internal or external short circuits, 15% were caused by charging and discharging, 7% were caused by accidental startup of equipment, and 10% were caused by other reasons. From the cause of the fire, electrical failure and spontaneous combustion is the main cause of electric vehicle fires, while overcharging, battery failure, electrical line short circuit is the root cause of the fire.

In this article we will take a look at lithium battery fire characteristics and lithium battery fire suppression tips and lithium battery fire suppression system types.

Table of Contents
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Characteristics of lithium-ion battery fires

Gas escape is one of the main manifestations of lithium-ion battery out of control. Lithium-ion battery fire, there will be a large amount of white smoke, which is mainly composed of lithium ion battery electrolyte vapors or decomposition products. In the early stage of the fire, the difference in smoke color is one of the most obvious features to distinguish lithium battery fire and common fire.

Lithium-ion battery thermal runaway, the decomposition of combustible gases mixed with air to form an explosive gas mixture, when the lithium battery ejected high temperature particles, in the local space will occur deflagration, resulting in the early stages of the fire is often accompanied by an explosion sound.

The fire was fast and long lasting. According to NFPA experiments, the fire spread rapidly within the power lithium-ion battery module in just a few seconds and lasted for about 27min.

High combustion temperature. Lithium-ion battery combustion is characterized by high temperatures, according to NFPA experiments, combustion in the battery outside the maximum temperature of up to 283-1090 degrees Celsius, the temperature inside the battery can be up to 572-1121 degrees Celsius, such high temperatures are enough to ignite the battery module inside the other combustible materials in the car, resulting in a larger fire.

Characteristics-of-lithium-ion-battery-fires

Extinguishing difficulties. For lithium batteries, most of the combustion reaction occurs inside the battery shell, the battery shell impedes the role of the extinguishing agent, in practice, lithium battery fire extinguishing time is often more than the firefighters carry oxygen cylinders for oxygen supply time, firefighters pose a certain threat to personal safety.

Prolonged spontaneous combustion or even explosion. Lithium batteries are capable of spontaneous combustion and subsequent explosion due to overheating. Causes of overheating include electrical short circuits, rapid discharge, overcharging, manufacturing defects, poor design or mechanical damage.

Overheating can lead to the process of “thermal runaway”, which is most likely to occur during the charging and discharging of lithium ion battery, i.e., an exothermic reaction within the battery that causes the temperature and pressure inside the battery to rise at a rapid rate, thus wasting energy.

4 tips for lithium battery fire suppression

(1) Cut off the power supply

(2) Block off flammable materials

(3) Sprinkle water (or other non-flammable liquid) on the device

Lithium batteries on fire cannot be extinguished with a dry powder fire extinguisher. Due to spontaneous combustion and explosion within the battery, a dry powder extinguisher will not work at this time, the best method is to use a large amount of water or other non-combustible liquid to cool down the unit in order to prevent the heat from spreading to the other cells in the battery. If water is not available, any non-flammable liquid can be used to cool the unit.

(4) Warning

  • Do not attempt to remove/pick up or move the unit.
  • Do not cover or wrap the unit or use ice or dry ice to cool the unit. Such isolation of the device will result in the heat of the device not being able to dissipate within a short period of time and will increase the danger.
  • After the device has cooled (e.g., after about 10 to 15 minutes) take it to a suitable empty container with a non-flammable liquid and immerse the device in it.

 

Lithium ion battery fire suppression system types

Gas lithium ion battery fire suppression system

If the response is timely, with perfluorohexanone as the representative of a variety of fully submerged gas fire suppression system can effectively extinguish open flames, fire and explosion suppression, especially on the suppression of the explosion, the gas has a greater advantage.

In the confined space injected into a certain proportion of gas and reach the inert concentration, even if the concentration of flammable and explosive gases in the range of the explosion limit, the ambient temperature is higher than the ignition point, flammable and explosive gases will not occur combustion and explosion. Therefore, gas fire extinguishing systems are often used in environments where explosion suppression is required.

Automatic sprinkler lithium ion battery fire suppression system

The biggest role of the “infinite” sprinkler system is cooling, sprinkler and fine water mist is all the fire extinguishing facilities can be achieved to really play a cooling effect, through the cooling, has been out of control of thermal runaway lithium-ion batteries out of control progress is slow.

Effectively inhibit the development of the fire, while cooling reduces the ambient temperature, resulting in adjacent batteries will not produce a cascade reaction successive thermal runaway, therefore, the global fire experts, generally agreed that in all fire suppression systems, sprinkler is the most effective.

Lithium-ion-battery-fire-suppression-system-types

Fine mist fire suppression systems

Although not as reliable as sprinklers for high-capacity lithium-ion battery fires, fine-mist systems are better suited for use in environments where sprinklers are difficult to set up than gaseous fire suppression systems.

Fine water mist basically does not cause leakage or external short-circuiting, which is more easily accepted by power experts, and is more adaptable to open racks without protective enclosures than sprinkler systems. Optimal alternative to sprinklers

Foam fire suppression system

Foam fire suppression systems are more suitable for liquid fires, especially for oils with a specific gravity less than water, and can be considered a specialized fire suppression system, rarely suitable for other material fires. From the analysis of technical principle, it is not suitable for battery fire.

Unless the oil depot and other places of last resort, other places try to avoid the use of foam fire extinguishing system, in the lithium-ion battery fire building places, including the charging pile garage, should be prohibited to use foam sprinkler fire extinguishing system. Call on the fire department as soon as possible to end the use of foam sprinkler system, the original system as far as possible to transform the removal.

Foam-fire-suppression-system

Dry powder lithium battery fire suppression system

Dry powder is the most unsuggested fire extinguishing effect of a lithium battery fire suppression system, does not have the ability to lower the temperature can not be used for electrical equipment and battery fire, a one-time consumption, and electrical equipment and batteries continue to heat especially easy to re-ignite.

And side effects of the largest, conductive, pollution, a spray, strong and weak electrical equipment, precision instruments, valuable electronic equipment, all waste, non-electronic equipment, by the dry powder contamination cleaning is particularly difficult, more difficult to clean than the foam, the same as the end of life.

Indoor and outdoor fire hydrant system is lithium battery fire suppression system must be equipped with lithium battery fire, firefighters are able to protect cooling as needed. Outdoor prefabricated cabin ESS power station, outdoor fire hydrant should adopt high pressure or temporary high pressure system, can directly use outdoor fire hydrant protection cooling.

Countermeasures to combat lithium-ion battery fire, not only from the lithium battery fire suppression system to find a way out, but also from the depth of the battery cabinet, the battery module of the integrated fire extinguishing device easier to solve the problem, to achieve the goal of a small fire input to improve fire safety capabilities.

In the cabinet outside the detection of fire and automatic start lithium battery fire suppression system, there is a certain time delay, this delay may lead to thermal runaway batteries can not be suppressed to the extent that it will not be able to achieve the fastest control of the lithium-ion battery fire risk, the longer the battery releases heat the greater the heat, which in turn causes more thermal runaway batteries! The longer the battery releases heat, the greater the heat, which in turn causes more battery thermal runaway, which is a vicious circle, so the inhibition time is very important.
Dry-powder-lithium-battery-fire-suppression-system

Lithium ion battery fire suppression system in battery swap station

Tycorun’s two wheeler battery swapping station has the function of real-time monitoring of temperature and smoke, and will automatically activate the fire extinguishing device when it detects an abnormality with real-time power-off protection. Tycorun as one of the top 10 battery swapping station manufacturers in China, its swappable battery is equipped with an intelligent BMS system, which effectively prevents and protects the lithium battery from overcharging and over-discharging.

The invention and successful use of the automatic lithium battery fire suppression device has attracted widespread attention from the fire fighting community. As a new type of fire suppression system, it solves the fire prevention problems of electrical equipment, control boxes, CNC machine tools, precision instruments and machining centers that have long plagued the fire protection industry.

The device consists mainly of a control system, a pressure vessel, a vessel valve, a smoke sensor, a temperature sensor, a flame detector and a release tube for releasing the extinguishing agent. The sensors are installed to detect the fire where it is most likely to occur. Once on fire, the sensor will quickly activate the control system to spray the extinguishing medium through the release tube to the protected area.

The integration of alarm and fire extinguishing, with fast detection and response time, quickly nips the fire in the bud and effectively reduces the economic losses caused by the fire.

lithium-ion-battery-fire-suppression-system-in-battery-swap-station

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