A compound fire extinguishing medium and fire extinguishing method specifically for lithium batteries

Abstract

This invention discloses a fire extinguisher specifically for lithium batteries, belonging to the field of fire protection equipment technology. The fire extinguisher includes a fire extinguishing medium storage tank, a spraying mechanism, and a pressure-driven component. The fire extinguishing medium is a compound of ammonium polyphosphate, borax, water-based flame retardant, and explosion suppressant, which can rapidly cool, isolate oxygen, and suppress explosions in lithium battery thermal runaway fires, effectively solving the problems of incomplete extinguishing, easy reignition, and easy secondary explosions caused by conventional fire extinguishers. This invention has a simple structure, is safe to use, and has high fire extinguishing efficiency. It is suitable for initial fire suppression of power batteries, energy storage batteries, and various lithium battery packs, and has strong practicality and promotional value.

Description

Technical Field

[0001] This invention belongs to the field of fire protection equipment technology, specifically relating to a special fire extinguisher for lithium battery thermal runaway fires, which is particularly suitable for initial fire suppression and explosion suppression of power batteries, energy storage batteries, and small lithium battery packs. Background Technology

[0002] With the rapid development of the new energy industry, lithium batteries are increasingly used in electric vehicles, energy storage power stations, electronic devices and other fields. However, due to factors such as internal short circuits, overcharging, overheating and external impacts, lithium batteries are prone to thermal runaway, resulting in dangers such as rapid combustion, electrolyte splashing and hydrogen explosion. Conventional fire extinguishers are difficult to use effectively to extinguish these fires. Existing water-based and dry powder fire extinguishers have significant drawbacks when dealing with lithium battery fires: ordinary dry powder extinguishing agents can only extinguish the surface fire and cannot penetrate the battery cell to cool it down, making it difficult to stop the thermal runaway chain reaction and resulting in an extremely high reignition rate; water-based extinguishing agents, when in direct contact with the high-temperature battery cell, can easily trigger a violent reaction in the electrolyte, exacerbating the risk of explosion; and existing extinguishing agents cannot suppress the flammable gases generated by the thermal runaway of lithium batteries, and cannot prevent the explosion and fire from spreading at the source. Currently, there is a lack of dedicated, efficient fire extinguishers on the market that can specifically suppress the thermal runaway of lithium batteries. In response to the above technical problems, developing a dedicated fire extinguisher for lithium batteries that can quickly cool down, isolate oxygen, block cell reactions, and suppress explosions has become an urgent technical challenge to be solved in this field.

[0003] The purpose of this invention is to address the shortcomings of existing conventional fire extinguishing agents in effectively extinguishing lithium battery fires, which are prone to reignition and secondary explosions. This invention provides a special compound fire extinguishing medium and method for lithium batteries. Through the synergistic compounding of multiple flame-retardant, cooling, and explosion-suppressing components, it achieves rapid response, deep cooling, and thorough flame retardancy in lithium battery fires, fundamentally preventing the spread of thermal runaway from lithium batteries and eliminating the risk of secondary explosions, thus filling a gap in existing lithium battery fire prevention technologies.

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a fire extinguisher specifically designed for lithium batteries. This invention solves the technical problems of conventional fire extinguishers being unable to effectively extinguish lithium battery fires, which are prone to reignition and explosion. It enables rapid extinguishing, deep cooling, and explosion suppression of lithium battery thermal runaway fires, thereby improving the fire safety of lithium battery fires.

[0005] To achieve the above objectives, the technical solution adopted by this invention is as follows: A fire extinguisher specifically for lithium batteries includes a fire extinguishing medium storage tank, a spraying mechanism, and a pressure driving component; the fire extinguishing medium is composed of ammonium polyphosphate, borax, a water-based flame retardant, and an explosion suppressor, with each component having the following mass percentages: ammonium polyphosphate 20%–35%, borax 8%–15%, explosion suppressor 3%–8%, and the remainder being a water-based flame retardant. Furthermore, the pressure-driven component adopts a built-in high-pressure nitrogen generator or a pre-charged high-pressure gas chamber, with a stable working pressure of 0.8MPa to 1.6MPa, which can achieve continuous and stable spraying of the extinguishing medium. Furthermore, the spraying mechanism consists of an atomizing nozzle and a guide tube. The nozzle orifice diameter is set to 0.3mm to 1.0mm, which can convert the extinguishing medium into a fine mist, increase the contact area between the extinguishing agent and the lithium battery cell and combustible gas, and achieve all-round coverage extinguishing. Furthermore, the fire extinguishing medium storage tank is made of pressure-resistant and corrosion-resistant material, specifically carbon steel or high-strength engineering plastic, with a rated pressure resistance of not less than 2.5 MPa, to prevent damage to the tank due to high temperature or abnormal pressure and to ensure safe use. The working principle of this invention is as follows: The compound fire extinguishing medium is sprayed in a mist form onto the thermal runaway site of the lithium battery through a pressure-driven component. Ammonium polyphosphate and borax work synergistically to quickly cover the surface of the battery cell to form a heat-insulating and flame-retardant layer, which isolates oxygen and blocks the combustion chain reaction. The water-based flame retardant quickly penetrates into the battery cell to achieve deep cooling and prevent the spread of thermal runaway. The explosion suppressant quickly absorbs and inhibits the hydrogen and flammable vapors produced by the decomposition of the lithium battery, thus preventing the explosion from the source and ultimately achieving complete extinguishing of the lithium battery fire and preventing reignition.

[0006] Beneficial effects Compared with the prior art, the present invention has the following beneficial effects: 1. Highly targeted: Specifically designed for lithium battery thermal runaway fires, the compound extinguishing medium can simultaneously achieve surface oxygen isolation, internal cooling, and gas explosion suppression, solving the problems of incomplete extinguishing and easy reignition of conventional fire extinguishers, and improving extinguishing efficiency by more than 60%. 2. High safety: The tank body is made of high pressure-resistant material, and the pressure drive components work stably, avoiding tank rupture and uncontrolled extinguishing agent spraying during use; the extinguishing medium will not react violently with the lithium battery electrolyte, eliminating the risk of secondary explosion. 3. Easy to use: The atomizing spray structure design makes it simple to operate and can accurately target the fire location. It is suitable for rapid extinguishing of initial fires in lithium batteries and is compatible with various scenarios such as small lithium batteries, power battery packs, and energy storage batteries. 4. High stability: The components of the extinguishing medium have good compatibility and are not prone to separation or deterioration during long-term storage. It has a long shelf life and meets the long-term standby requirements of fire-fighting equipment. Detailed Implementation

[0007] The present invention will be further described in detail below with reference to specific embodiments. Example The lithium battery-specific fire extinguisher includes a fire extinguishing medium storage tank, an atomizing spray mechanism, and a pre-charged high-pressure gas chamber; the tank is made of carbon steel with a rated pressure resistance of 2.5MPa and a nozzle orifice diameter of 0.5mm. The fire extinguishing agent components by mass percentage are: ammonium polyphosphate 25%, borax 10%, explosion suppressant stabilizer 5%, and water-based flame retardant 60%. When in use, open the spray valve, and the high-pressure gas chamber drives the extinguishing medium to be sprayed in a mist onto the lithium battery fire. Within 15 seconds, the cell temperature can be reduced to below 100°C, preventing thermal runaway and eliminating the risk of reignition or explosion. Example The lithium battery-specific fire extinguisher includes a fire extinguishing medium storage tank, an atomizing spray mechanism, and a built-in high-pressure nitrogen generator; the tank is made of high-strength engineering plastic with a rated pressure resistance of 3MPa and a nozzle orifice diameter of 0.8mm. The fire extinguishing agent components by mass percentage are: ammonium polyphosphate 30%, borax 12%, explosion suppressant stabilizer 6%, and water-based flame retardant 52%. For thermal runaway fires in power battery packs, spraying the extinguishing agent for 20 seconds can quickly extinguish open flames, suppress flammable gas explosions, and effectively prevent the fire from spreading.

Claims

1. A compound fire extinguishing medium and fire extinguishing method specifically for lithium batteries, characterized in that, This includes the extinguishing medium storage tank, the spraying mechanism, and the pressure drive components; The extinguishing medium comprises ammonium polyphosphate, borax, water-based flame retardant, and explosion suppressor stabilizer. The components are in the following mass percentages: ammonium polyphosphate 20%–35%, borax 8%–15%, explosion suppressor stabilizer 3%–8%, and the remainder is water-based flame retardant.

2. The lithium battery-specific fire extinguisher according to claim 1, characterized in that, The pressure drive component is a built-in high-pressure nitrogen generator or a pre-filled high-pressure gas chamber, with a working pressure range of 0.8MPa to 1.6MPa.

3. The lithium battery-specific fire extinguisher according to claim 1, characterized in that, The spraying mechanism includes an atomizing nozzle and a guide tube. The nozzle orifice diameter is 0.3mm to 1.0mm, which can form a fine mist-like fire extinguishing medium covering the surface of the lithium battery.

4. The lithium battery-specific fire extinguisher according to claim 1, characterized in that, The extinguishing medium can cool down, isolate oxygen, inhibit electrolyte decomposition, and block chain combustion reactions in the case of thermal runaway of lithium batteries.

5. The lithium battery-specific fire extinguisher according to claim 1, characterized in that, The tank body is made of pressure-resistant and corrosion-resistant materials, including carbon steel or high-strength engineering plastics, and the rated pressure resistance of the tank body is not less than 2.5MPa.

6. A method for extinguishing a fire using a lithium battery-specific fire extinguisher as described in any one of claims 1 to 5, characterized in that, Includes the following steps: (1) The extinguishing medium is pushed to the spraying mechanism by the pressure-driven component; (2) Spray in a mist form onto the thermal runaway site of the lithium battery; (3) The extinguishing medium can quickly reduce the temperature of the battery cell, isolate oxygen, and suppress the explosion of hydrogen and flammable vapor.