Fire-extinguishing explosion-proof device and foam generating front end thereof

Abstract

The invention discloses a fire extinguishing explosion-proof device and a foam generating front end thereof, the foam generating front end comprises a shell with a cavity, the foam generating front end is provided with a foam spraying channel, a first liquid input channel and a first gas input channel, and valves are assembled in the first liquid input channel and the first gas input channel; a foaming net dividing the cavity into a mixing chamber and a foaming chamber is assembled in the shell, the foaming chamber is communicated with the foam spraying channel, and the mixing chamber is communicated with the first liquid input channel and the first gas input channel. The gas-liquid mixture is mixed for multiple times by utilizing the primary mixing inner cabin, the primary mixing outer cabin, the secondary mixing cabin and the tertiary mixing cabin before foaming, the gas-liquid mixing effect is enhanced, the foaming rate and the foam fire extinguishing effect are improved, different types of fire extinguishing foams can be generated, and different fire extinguishing modes are matched, so that the fire extinguishing effect is improved. The system can be suitable for different types of fire scenes in an energy storage battery thermal safety management system, and the functions of the system are enriched.

Description

Technical Field

[0001] This invention relates to the field of foaming device technology, and in particular to a fire extinguishing and explosion-proof device and its foam generating front end. Background Technology

[0002] Currently, with the rapid development of the new energy industry, compound fire accidents caused by battery thermal runaway have increased significantly. Foam extinguishing is one of the most commonly used fire extinguishing methods to deal with various fire scenes. This method mainly involves mechanically mixing foam extinguishing agent with water in a certain proportion, generating extinguishing foam through foaming equipment, and using the foam to cover the surface of the burning material, isolating oxygen and cooling it down to extinguish the fire. The basic structure of the foaming equipment includes a shell, a foaming net, a mixing chamber, and a pressure regulating system. During the foaming process, the mixture of liquid and gas containing foaming agent forms a gas-liquid mixture in the mixing chamber. The gas-liquid mixture first impacts the first layer of foaming net to form initial fine bubbles, and subsequent net layers gradually refine the bubbles, ultimately outputting foam with a bubble diameter of 0.5-2mm.

[0003] However, traditional gas-liquid mixing foaming devices (compressed air + water) have significant limitations in dealing with thermal runaway fires in new energy batteries. On the one hand, traditional foaming devices are set up with fixed liquid pipes and fixed air pipes connected together, plus fine mesh foaming. The gas and liquid are not thoroughly mixed before foaming, resulting in low foaming efficiency. The sprayed foam is prone to obvious water lines and uneven foam density, ultimately leading to low fire extinguishing efficiency. On the other hand, the type of fire extinguishing foam and the fire extinguishing method should be different for different types of fire scenes. However, traditional foaming devices have a single function and can only cope with a limited number of application scenarios, which also leads to poor fire extinguishing effect. Summary of the Invention

[0004] To address the technical problems existing in the background art, the present invention proposes a fire extinguishing and explosion-proof device and its foam generating front end.

[0005] The present invention proposes a foam generating front end, comprising a shell with a chamber, the foam generating front end having a foam ejection channel, a first liquid input channel and a first gas input channel, both of which are equipped with valves, and a foaming net is installed inside the shell to divide the chamber into a mixing chamber and a foaming chamber, the foaming chamber being connected to the foam ejection channel, and the mixing chamber being connected to the first liquid input channel and the first gas input channel.

[0006] Preferably, the foam generating front end also has a premixing chamber, a first gas input channel is connected to the mixing chamber through the premixing chamber, and a first liquid input channel is connected to the premixing chamber and directly leads to the mixing chamber.

[0007] Preferably, the premixing chamber is arranged around the first liquid input channel, the premixing chamber and the first liquid input channel are separated by the wall of the first liquid input channel, the premixing chamber and the mixing chamber are separated by the wall of the mixing chamber, a plurality of first through holes are uniformly opened on the portion of the first liquid input channel wall surrounding the premixing chamber to connect the premixing chamber and the first liquid input channel, and a plurality of second through holes are uniformly opened on the portion of the mixing chamber wall surrounding the premixing chamber to connect the premixing chamber and the mixing chamber.

[0008] Preferably, the foam generating front end also has a second liquid input channel and a second gas input channel that are both connected to the premixing chamber, and valves are installed in both the second liquid input channel and the second gas input channel.

[0009] Preferably, the foam generating front end further includes a baffle that divides the mixing chamber into a first mixing unit and a second mixing unit. The first mixing unit is connected to the premixing chamber. The baffle has a plurality of third through holes that connect the first mixing unit and the second mixing unit, and all the third through holes face the inner wall of the second mixing unit.

[0010] Preferably, the baffle has a first wall located on one side of the first mixing unit. The first wall is coaxially arranged with the wall of the first liquid input channel. The inner diameter of the first wall gradually increases in the direction close to the foam ejection channel. A plurality of third through holes are arranged in a ring array around the axis of the first wall. The third through holes are arranged close to the foam ejection channel.

[0011] Preferably, the baffle is provided with a conical groove located on one side of the second mixing unit. The conical groove is coaxially arranged with the first wall, and the third through holes all face the inner wall of the second mixing unit. Specifically, the third through holes all face the inner wall of the conical groove.

[0012] Preferably, the foam ejection channel forms a constriction at one end relative to the second mixing unit.

[0013] The present invention includes a fire extinguishing and explosion-proof device having the above-mentioned foam generating front end.

[0014] In this invention, by adjusting the air pressure in the primary mixing outer chamber and the water pressure and flow rate in the primary mixing inner chamber, the gas can be injected into the liquid in the form of high-pressure pulses. This causes the gas and liquid to repeatedly oscillate and mix between the primary mixing inner and outer chambers, initially improving the gas-liquid mixing effect. Then, the flow direction of the gas-liquid mixture is changed by the second mixing chamber, forming turbulence and eddies to further improve the gas-liquid mixing effect. Finally, the gas-liquid mixture is backflushed by the third mixing chamber for further mixing. This invention can fully mix the gas and liquid before foaming, improving the foaming rate and fire extinguishing effect.

[0015] By setting up two gas input channels to change the type of gas input into the foam generator front end, different types of fire extinguishing foam can be generated to suit different types of fire scenarios, thus enriching the functionality of the invention. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the foam generation front end in Embodiment 1 of the present invention; Figure 2 This is a cross-sectional view of the foam generation front end in Embodiment 1 of the present invention; Figure 3 This is a cross-sectional view of the baffle at the foam generation front end in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the foam generating front end installed in a fire extinguishing and explosion-proof device with an energy storage battery thermal safety management system, as shown in Example 1. Figure 5 This is a schematic diagram of the overall structure of the foam generation front end in Embodiment 2 of the present invention. Detailed Implementation

[0017] Example 1

[0018] Reference Figure 1 This invention proposes a foam generating front end, comprising a shell 1 with a chamber 2. The foam generating front end has a foam ejection channel 11, a first liquid input channel 12, a first gas input channel 13, and a second gas input channel 15. The first liquid input channel 12 connects to a water tank containing fire-fighting water and a foaming agent solution tank containing foaming agent solution. Valves are installed in the first liquid input channel 12, the first gas input channel 13, and the second gas input channel 15. This foam generating front end is installed... Figure 4 The fire extinguishing and explosion-proof device 6, which has a thermal safety management system for energy storage batteries, can extinguish fires in a timely manner when a fire occurs in the energy storage system, prevent the fire from spreading further, and reduce property damage.

[0019] The housing 1 is equipped with a foaming net 5 that divides the chamber 2 into a mixing chamber 21 and a foaming chamber 22. The foaming chamber 22 is connected to the foam ejection channel 11. The mixing chamber 21 is connected to the first liquid input channel 12 and the first gas input channel 13. Outside the mixing chamber 21, there is a premixing chamber 23. The premixing chamber 23 is arranged around the first liquid input channel 12. The first gas input channel 13 is connected to the mixing chamber 21 through the premixing chamber 23. The first liquid input channel 12 is connected to the premixing chamber 23 and directly leads to the mixing chamber 21. The second gas input channel 15 is connected to the premixing chamber 23.

[0020] The gas entering the housing 1 through the first gas input channel 13 or the second gas input channel 15 is mixed with the liquid entering the housing 1 through the first liquid input channel 12, and then passes through the foaming net 5 to form fire-fighting foam that can be used for fire extinguishing.

[0021] It is known that the foaming effect of fire-fighting foam is directly proportional to the degree of mixing between the gas and liquid. Therefore, in order to enhance the mixing effect between different materials, this embodiment refers to... Figure 2 The premixing chamber 23 is separated from the first liquid input channel 12 by the wall of the first liquid input channel 12, and the premixing chamber 23 is separated from the mixing chamber 21 by the wall of the mixing chamber 21. A plurality of first through holes 41 are evenly provided on the wall portion of the first liquid input channel 12 surrounding the premixing chamber 23 to connect the premixing chamber 23 and the first liquid input channel 12. A plurality of second through holes 42 are evenly provided on the wall portion of the mixing chamber 21 surrounding the premixing chamber 23 to connect the premixing chamber 23 and the mixing chamber 21. The premixing chamber 23, enclosed by the walls of the first liquid input channel 12, the mixing chamber 21, and the conical plate on the shell 1, serves as the primary mixing outer chamber. The area within the first liquid input channel 12 with the first through-hole 41 serves as the primary mixing inner chamber. The gas involved in foaming enters the primary mixing outer chamber through the first gas input channel 13, while the liquids involved in foaming (firefighting water and foaming agent) enter the primary mixing inner chamber through the first liquid input channel 12. Then, by adjusting the air pressure within the primary mixing outer chamber, when the water pressure within the primary mixing inner chamber is greater than the air pressure within the primary mixing outer chamber, the liquid passes through the first through-hole 41 into the primary mixing outer chamber for further processing. The mixture is then passed through the second through-hole 42 into the mixing chamber 21. When the water pressure in the initial mixing chamber is lower than the air pressure in the initial mixing outer chamber, the gas passes through the first through-hole 41 into the initial mixing chamber for mixing, and then enters the mixing chamber 21 through the first liquid input channel 12. In this way, by repeatedly adjusting the air pressure in the initial mixing outer chamber, the air pressure can be changed in the form of pulses, allowing high-pressure gas to be repeatedly and continuously inserted into the mixed liquid to form a gas-liquid mixture. During this process, the gas and liquid repeatedly enter and exit between the initial mixing chamber and the initial mixing outer chamber, causing the water and gas to repeatedly oscillate and mix, so as to initially improve the mixing effect of water and gas.

[0022] Next, to further improve the gas-liquid mixing effect, such as Figure 2 and Figure 3 As shown, the foam generating front end also includes a baffle 3 that divides the mixing chamber 21 into a first mixing unit 211 and a second mixing unit 212. The first mixing unit 211 is connected to the premixing chamber 23. The baffle 3 has a plurality of third through holes 43 that connect the first mixing unit 211 and the second mixing unit 212. Furthermore, the baffle 3 has a first wall 31 located on one side of the first mixing unit 211. The first wall 31 is coaxially arranged with the wall of the first liquid input channel 12. The inner diameter of the first wall 31 gradually increases in the direction close to the foam ejection channel 11. A plurality of third through holes 43 are arranged in a ring array around the axis of the first wall 31. The third through holes 43 are arranged close to the foam ejection channel 11. The above configuration enables the first wall 31 to be conical, forming a secondary mixing chamber with an inclined inner wall within the first mixing unit 211. The gas-liquid mixture formed after mixing in the primary mixing outer chamber and the primary mixing inner chamber enters the secondary mixing chamber and impacts the outer side of the first wall 31, changing the flow direction. Then, it collides again with the inner wall of the mixing chamber 21, changing the flow direction again, forming turbulence and eddies in the secondary mixing chamber to further improve the gas-liquid mixing effect.

[0023] Then, the gas-liquid mixture, after being mixed again in the second mixing chamber, will pass through the third through-hole 43 into the second mixing unit 212, in order to further mix this portion of the gas-liquid mixture, such as... Figure 3 As shown: A conical groove 32 located on one side of the second mixing unit 212 is also provided on the baffle 3. The conical groove 32 serves as a three-mixing chamber. The conical groove 32 is coaxially arranged with the first wall 31. The third through holes 43 all face the inner wall of the conical groove 32. This arrangement allows the gas-liquid mixture entering the three-mixing chamber to collide with the inner wall of one side of the conical groove 32, causing the flow direction of the gas-liquid mixture to change again. Then, the gas-liquid mixture that has been redirected will impact the inner side of the first wall 31 again, forming a backflow, thereby improving the mixing effect of the gas-liquid mixture again.

[0024] Finally, the repeatedly mixed gas-liquid mixture flows to the foaming net 5, where it is foamed. This foaming net 5 has a multi-layered structure. As the thoroughly mixed gas-liquid mixture passes through the foaming net 5, it first forms initial fine bubbles through the first layer of foaming net 5, and then the bubbles are gradually refined by subsequent layers of foaming net 5 until a uniformly dense fire-extinguishing foam is formed. Furthermore, the foam ejection channel 11 is narrowed at one end relative to the second mixing unit 212. This design also helps to increase the flow velocity of the outlet foam, allowing the generated fire-fighting foam to be ejected at a higher speed, thus improving the fire-extinguishing effect.

[0025] In addition, it is worth noting that in this embodiment, two different types of gas can be introduced into the foam generating front end through the first gas input channel 13 and the second gas input channel 15: for example, the first gas input channel 13 is connected to a storage tank containing inert gas (carbon dioxide gas or nitrogen gas), and the second gas input channel 15 is connected to a storage tank containing heptafluoropropane gas. In this way, by controlling the valves on the two gas input channels, different gases can be controlled to enter the foam generating front end, thereby generating carbon dioxide foam containing inert gas and heptafluoropropane foam containing heptafluoropropane gas.

[0026] It is worth emphasizing that the liquids entering the foam generation stage during the above process include ordinary fire-fighting water and foaming agent solution. Due to the large amount of water added, the generated foam is all wet foam. When dry foam is needed for an actual fire, the water tank valve connected to the first liquid input channel 12 can be closed, so that only foaming agent solution enters the foam generation stage. In this way, by reducing the content of fire-fighting water in the foam generation stage, carbon dioxide dry foam and heptafluoropropane dry foam can be produced. Dry foam is more suitable for extinguishing liquid fires than wet foam, as it can quickly cover and isolate the fire, achieving smothering and effectively preventing reignition.

[0027] Compared to existing foam generating devices, this embodiment can not only generate different types of fire extinguishing foam, but also provide multiple fire extinguishing modes to suit different fire scenarios, and is especially suitable for extinguishing fires. Figure 4 The fire was caused by thermal runaway of the battery pack within the thermal safety management system of the energy storage battery.

[0028] The following will further illustrate this embodiment with specific fire scenarios: 1) Gas extinguishing mode By independently opening the valve on the second gas input channel 15, which connects to heptafluoropropane gas, heptafluoropropane gas is sprayed into the fire scene. By utilizing the interruption of the combustion reaction chain and the physical adsorption and cooling effect of heptafluoropropane gas, Class A, Class B (liquid fires), Class C (gas fires), and Class E (electrical fires) fires are effectively extinguished, resulting in rapid fire suppression without secondary damage.

[0029] 2) Foam-enhanced fire extinguishing mode When the fire is large or the single gas extinguishing method is not effective and the fire is spreading, carbon dioxide foam or heptafluoropropane foam can be selected based on the type of fire, in addition to gas extinguishing (the choice between dry foam and wet foam can be switched according to the actual fire situation). ①For fuel fires: The valves on the first liquid input channel 12 and the first gas input channel 13 connected to carbon dioxide gas can be opened directly to generate carbon dioxide foam directly at the foam generator front end. The carbon dioxide foam can be used to directly cover the burning material to achieve efficient suffocation fire extinguishing. ② For fires involving new energy batteries: The valves on the first liquid input channel 12 and the second gas input channel 15, which connects to heptafluoropropane gas, can be directly opened to generate heptafluoropropane foam. Heptafluoropropane foam has both chemical inhibition and oxygen isolation functions, which can not only extinguish fires, but also solve the problem that traditional foams are ineffective against battery thermal runaway. Moreover, the chemical inhibition effect of heptafluoropropane foam is close to that of perfluorohexanone liquid, but the cost can be reduced by 30%-50%.

[0030] Compared to traditional compressed air foam, the carbon dioxide foam or heptafluoropropane foam generated by this invention has stronger adaptability, faster fire extinguishing speed, better coverage, and better resistance to reignition.

[0031] 3) Explosion suppression and reignition prevention mode ①For fires in enclosed spaces: The valve on the first gas input channel 13 can be opened separately to spray carbon dioxide or nitrogen into the fire scene, reducing the oxygen concentration in the enclosed space and suppressing the explosion. ② For open / semi-open spaces: close the water tank valve, open the valves on the first liquid input channel 12 and the first gas input channel 13, close the water tank valve, generate carbon dioxide dry foam through the foam generator front end, and use the suffocation fire extinguishing and covering isolation functions of carbon dioxide dry foam to effectively prevent reignition.

[0032] Example 2

[0033] Unlike in Example 1, as Figure 5 As shown: In this embodiment, the foam generator front end also has a second liquid input channel 14, which is equipped with a valve and is connected to the premixing chamber 23. By opening the valve on the second liquid input channel 14, ultrapure water (deionized water) can be sprayed directly onto the fire scene, providing a new fire extinguishing mode, as shown below: 4) Flooding Extinguishing Mode ①For fire scenes with high-precision electrical equipment: When the fire is extremely serious, ultrapure water can be sprayed directly into the conventional Class A fire (solid fire) scene by opening the valve on the second liquid input channel 14. Ultrapure water can be used as the fire extinguishing medium and can also cool down the high-temperature equipment. It can also prevent the high-precision electrical equipment in the energy storage system from being damaged by water, thereby reducing the economic losses at the fire scene. ②For fire scenes with ordinary equipment: When the fire is extremely serious, the water tank valve on the water tank connected to the first liquid input channel 12 can be opened directly, the valve on the foaming agent solution tank can be closed, and then the valve on the first liquid input channel 12 can be opened to allow ordinary fire water to be injected into the fire scene in a large flow rate through the front end of the foam generator to achieve the fire extinguishing effect.

[0034] This invention supports free switching between three states: gas, foam, and liquid. It also supports automatic switching of agents and generation of different types of fire extinguishing foam, reducing operational complexity and flexibly adapting to various fire scenarios in energy storage battery thermal safety management systems.

[0035] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A foam generating front end, characterized in that, The device includes a shell with chambers. The foam generating front end has a foam ejection channel, a first liquid input channel, and a first gas input channel. Valves are installed in both the first liquid input channel and the first gas input channel. A foaming net is installed inside the shell, dividing the chambers into a mixing chamber and a foaming chamber. The foaming chamber is connected to the foam ejection channel, and the mixing chamber is connected to both the first liquid input channel and the first gas input channel. The foam generating front end also has a premixing chamber. The first gas input channel connects to the mixing chamber through the premixing chamber, and the first liquid input channel connects to and directly leads to the mixing chamber. The premixing chamber is arranged around the first liquid input channel. The premixing chamber and the first liquid input channel are separated by the wall of the first liquid input channel, and the premixing chamber and the mixing chamber are separated by the wall of the mixing chamber. A plurality of first through holes are evenly distributed on the first liquid input channel wall surrounding the premixing chamber to connect the premixing chamber and the first liquid input channel. A plurality of second through holes are evenly distributed on the mixing chamber wall surrounding the premixing chamber to connect the premixing chamber and the mixing chamber.

2. The foam generating front end according to claim 1, characterized in that, The foam generator front end also has a second liquid input channel and a second gas input channel that are both connected to the premixing chamber, and valves are installed in both the second liquid input channel and the second gas input channel.

3. The foam generating front end according to claim 2, characterized in that, The foam generating front end also includes a baffle that divides the mixing chamber into a first mixing unit and a second mixing unit. The first mixing unit is connected to the premixing chamber. The baffle has several third through holes that connect the first mixing unit and the second mixing unit. All the third through holes face the inner wall of the second mixing unit.

4. The foam generating front end according to claim 3, characterized in that, The baffle has a first wall located on one side of the first mixing unit. The first wall is partially coaxial with the wall of the first liquid input channel. The inner diameter of the first wall gradually increases in the direction close to the foam ejection channel. Multiple third through holes are arranged in a ring array around the axis of the first wall. The third through holes are arranged close to the foam ejection channel.

5. The foam generating front end according to claim 4, characterized in that, The baffle has a conical groove located on one side of the second mixing unit. The conical groove is coaxially arranged with the first wall. The third through holes all face the inner wall of the second mixing unit. Specifically, the third through holes all face the inner wall of the conical groove.

6. The foam generating front end according to claim 5, characterized in that, The foam ejection channel forms a constriction at one end relative to the second mixing unit.

7. A fire extinguishing and explosion-proof device, characterized in that, Includes the foam generating front end as described in any one of claims 1-6.

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