High-temperature self-triggering fire extinguishing device for battery pack of electric vehicle

Abstract

A high-temperature self-triggering fire extinguishing device for a battery pack of an electric vehicle is installed between an upper cover of the battery pack and a chassis metal plate, a fire extinguishing agent fixing frame is fixed to the chassis metal plate and faces the battery pack, a heat insulation and flame retardant sleeve is fixed to the fire extinguishing agent fixing frame, and a fire extinguishing agent is contained in the heat insulation and flame retardant sleeve. The thermosensitive wire is arranged in the fire extinguishing agent, and the side, facing the battery pack, of the thermosensitive wire is exposed out of the fire extinguishing agent. According to the high-temperature self-triggering fire extinguishing device, the fire extinguishing timeliness and the vehicle safety are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of thermal runaway of electric vehicle battery packs, and in particular to a high-temperature self-triggering fire extinguishing device for electric vehicle battery packs. Background Art

[0002] In the prior art, the high-temperature insulating material between the battery module and the upper cover has poor impact resistance and thermal insulation. When a single cell or module has thermal runaway, the explosion-proof valve of the single cell opens, and high-temperature flames, high-temperature solids (diaphragms, positive and negative pole pieces), high-temperature liquids (electrolytes), high-temperature gases (electrochemical reactants), etc. will be directly sprayed onto the high-temperature insulating material between the battery pack upper cover and the battery module. This high-temperature insulating material is generally mica or glass fiber. However, such materials have the following problems due to their own physical properties and production process problems: When a module or cell has a large-scale thermal runaway, its protective material will weaken its protective performance due to the impact of the three-phase high-temperature solid, liquid, and gas it ejects, causing the temperature of the battery pack upper cover to rise rapidly, thereby causing damage to the components outside the battery pack upper cover. The upper cover of the battery pack is generally a metal upper cover and is plated with electrophoretic paint, and the components of the electrophoretic paint are generally bridging agents, neutralizers, resins, cosolvents, and dyes. The electrophoretic paint will melt and continue to burn at high temperatures. When the battery pack experiences thermal runaway, the protective performance of its protective material will be weakened and the high temperature generated will cause the electrophoretic paint on the outside of the battery pack cover to melt and burn, posing a great threat to the chassis above the battery pack cover. There is no fireproof and heat-insulating device between the battery pack and the vehicle chassis. When the battery pack experiences thermal runaway, the burning of the electrophoretic paint on the battery pack cover will directly burn the chassis, and the carpet covering the chassis is easy to burn due to its low temperature resistance, posing a great threat to the lives of the passengers.

[0003] The above information disclosed in the background technology section is only used to enhance the understanding of the background of the present invention and therefore may contain information that does not constitute the prior art known to ordinary technicians in this field. Utility Model Content

[0004] The utility model aims to provide a high-temperature self-triggering fire extinguishing device for an electric vehicle battery pack, so as to improve the timeliness of fire extinguishing and the safety of the vehicle.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] The utility model discloses a high-temperature self-triggering fire extinguishing device for an electric vehicle battery pack, which is installed between the upper cover of the battery pack and the chassis sheet metal. The high-temperature self-triggering fire extinguishing device includes:

[0007] A fire extinguishing agent fixing frame, which is fixed to the chassis sheet metal and faces the battery pack,

[0008] A heat-insulating flame-retardant sleeve fixed to the fire-extinguishing agent fixing frame,

[0009] a fire extinguishing agent contained in the heat-insulating flame-retardant sleeve,

[0010] The heat-sensitive wire is disposed in the fire extinguishing agent and is exposed to the fire extinguishing agent at a side facing the battery pack.

[0011] In a high-temperature self-triggered fire extinguishing device for an electric vehicle battery pack, the fire extinguishing agent block is located directly above the pressure relief valve of the battery pack.

[0012] In a high-temperature self-triggered fire extinguishing device for an electric vehicle battery pack, the fire extinguishing agent fixing frame is a grid structure covering the battery pack.

[0013] In a high-temperature self-triggered fire extinguishing device used in an electric vehicle battery pack, the grid structure includes a plurality of rectangular grids in an array.

[0014] In a high-temperature self-triggered fire extinguishing device used in an electric vehicle battery pack, the high-temperature self-triggered fire extinguishing device is detachably connected to the chassis of the electric vehicle via bolts.

[0015] In the high-temperature self-triggered fire extinguishing device used in the battery pack of an electric vehicle, the heat-insulating flame-retardant sleeve is a door-shaped structure.

[0016] In a high-temperature self-triggered fire extinguishing device used in an electric vehicle battery pack, the door-shaped structure includes a pair of horizontal side walls and a vertical wall connecting the side walls.

[0017] In the high-temperature self-triggered fire extinguishing device used in the battery pack of an electric vehicle, the fire extinguishing agent is filled in the heat-insulating flame-retardant sleeve.

[0018] In a high-temperature self-triggered fire extinguishing device for an electric vehicle battery pack, the heat-sensitive wire is buried in the fire extinguishing agent and is exposed to the fire extinguishing agent on one side facing the battery pack.

[0019] In the high-temperature self-triggered fire extinguishing device for an electric vehicle battery pack, the high-temperature self-triggered fire extinguishing device for an electric vehicle battery pack is a symmetrical structure.

[0020] In the above technical scheme, the utility model provides a high-temperature self-triggering fire extinguishing device for an electric vehicle battery pack, which has the following beneficial effects: the high-temperature self-triggering fire extinguishing device for an electric vehicle battery pack is arranged between the outer side of the battery pack cover and the chassis. When the battery pack is thermally runaway, the high temperature generated by it will trigger the high-temperature triggering fire extinguishing device arranged on the outer side of the battery pack cover. When the fire extinguishing device is triggered, metal salt particles will be generated. The metal salt particles absorb a large amount of heat at high temperature, and physical endothermic processes such as heat melting and gasification will occur. The flame temperature is reduced, and then the heat radiated to the combustion surface of the combustible material for gasifying the combustible molecules and cracking the gasified combustible molecules into free radicals will be reduced, and the combustion reaction rate will be suppressed to a certain extent. At the same time, the metal ions and solid particles generated by it react with the active groups in the combustion group to further suppress the combustion reaction. Thereby preventing the flame from directly burning the chassis and igniting the carpet, ensuring the safety of the passenger compartment. On the other hand, the N2 and CO2 generated by the fire extinguishing device will be retained between the chassis and the upper cover of the box for a relatively long time, reducing the oxygen concentration in the environment, preventing high temperature from igniting other components, and further ensuring the safety of the passenger compartment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present utility model. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0022] Figure 1 The utility model is a schematic diagram of the installation of a high-temperature self-triggering fire extinguishing device for an electric vehicle battery pack.

[0023] Figure 2 The utility model is a schematic diagram of the fixing structure of the high-temperature self-triggering fire extinguishing device for an electric vehicle battery pack.

[0024] Figure 3 The utility model is a schematic diagram of the position structure of the high-temperature self-triggered fire extinguishing device for an electric vehicle battery pack.

[0025] Figure 4 The utility model is a structural schematic diagram of a high-temperature self-triggering fire extinguishing device for an electric vehicle battery pack.

[0026] Figure 5 The utility model is a structural schematic diagram of a high-temperature self-triggering fire extinguishing device for an electric vehicle battery pack. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the implementation of the utility model clearer, the technical solution in the implementation of the utility model will be clearly and completely described below in conjunction with the drawings in the implementation of the utility model. Obviously, the described implementation is a part of the implementation of the utility model, not all of the implementations. Based on the implementation of the utility model, all other implementations obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0030] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0031] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0032] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0034] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0035] like Figure 1-5 As shown, in one embodiment, a high-temperature self-triggering fire extinguishing device for an electric vehicle battery pack of the utility model includes:

[0036] It is installed between the battery pack cover 1-2 and the chassis sheet metal 1-4. The high-temperature self-triggered fire extinguishing device 1-3 includes:

[0037] The fire extinguishing agent fixing frame 3-4 is fixed to the chassis sheet metal 1-4 and faces the battery pack 1-1,

[0038] The heat-insulating flame-retardant sleeve 3-1 is fixed to the fire-extinguishing agent fixing frame 3-4,

[0039] The fire extinguishing agent 3-2 is contained in the heat-insulating flame-retardant sleeve 3-1,

[0040] The heat-sensitive wire 3 - 3 is disposed in the fire extinguishing agent and is exposed to the fire extinguishing agent at a side facing the battery pack.

[0041] In a preferred embodiment of the high-temperature self-triggered fire extinguishing device for an electric vehicle battery pack, the fire extinguishing agent block is located directly above the pressure relief valve of the battery pack.

[0042] In a preferred embodiment of a high-temperature self-triggered fire extinguishing device for an electric vehicle battery pack, the fire extinguishing agent fixing frame 3-4 is a grid structure covering the battery pack.

[0043] In a preferred embodiment of the high-temperature self-triggered fire extinguishing device for an electric vehicle battery pack, the grid structure includes a plurality of rectangular grids in an array.

[0044] In a preferred embodiment of the high-temperature self-triggered fire extinguishing device for an electric vehicle battery pack, the high-temperature self-triggered fire extinguishing device is detachably connected to the chassis of the electric vehicle via bolts 2-1.

[0045] In a preferred embodiment of a high-temperature self-triggered fire extinguishing device for an electric vehicle battery pack, the heat-insulating flame-retardant sleeve 3-1 is a door-shaped structure.

[0046] In a preferred embodiment of a high-temperature self-triggered fire extinguishing device for an electric vehicle battery pack, the gate-shaped structure includes a pair of horizontal side walls and a vertical wall connecting the side walls.

[0047] In a preferred embodiment of a high-temperature self-triggered fire extinguishing device for an electric vehicle battery pack, the fire extinguishing agent is filled in the heat-insulating flame-retardant sleeve 3-1.

[0048] In a preferred embodiment of the high-temperature self-triggered fire extinguishing device for an electric vehicle battery pack, the thermosensitive wire 3 - 3 is buried in the fire extinguishing agent and exposed to the fire extinguishing agent on one side facing the battery pack.

[0049] In a preferred embodiment of the high-temperature self-triggered fire extinguishing device for an electric vehicle battery pack, the high-temperature self-triggered fire extinguishing device for an electric vehicle battery pack is a symmetrical structure.

[0050] In one embodiment, Figure 1 As shown, the high-temperature self-triggered fire extinguishing device 1-3 is an independent component installed between the battery pack cover 1-2 and the chassis sheet metal 1-4. When the battery cell has thermal runaway, the high temperature generated will ignite the electrophoretic paint on the outside of the battery pack cover 1-2. When the electrophoretic paint burns, the high temperature and flame generated will automatically trigger the fire extinguishing device 1-3. When the fire extinguishing device is triggered, the ejected material will produce a series of chemical reactions with the flame to inhibit the combustion reaction of the electrophoretic paint, thereby reducing the harm of the burning of the electrophoretic paint on the battery pack cover to the passenger compartment.

[0051] like Figure 2 As shown, the high temperature self-triggered fire extinguishing device is connected to the vehicle chassis by bolts 2-1 or welding.

[0052] like Figure 3-4As shown, the high-temperature self-triggered fire extinguishing device is composed of a thermal wire 3-3, a fire extinguishing agent 3-2, a fire extinguishing agent fixing frame 3-4, and a heat-insulating flame-retardant sleeve 3-1. The main function of the thermal wire 3-3 is to ignite the thermal wire 3-3 when the fire extinguishing device encounters an open flame or the temperature reaches 170°C, thereby activating the fire extinguishing agent 3-2 in the fire extinguishing device; the main function of the fire extinguishing agent 3-2 is to decompose the chemical coolant through the heat released by the redox reaction, so that the generating agent and the coolant can jointly participate in the fire extinguishing; the main function of the fire extinguishing agent fixing frame 3-4 is to fix the fire extinguishing agent 3-2 in the corresponding area to achieve multiple targeted triggering, and the function of the heat-insulating flame-retardant sleeve 3-1 is to reduce the combustion specific surface area of ​​the fire extinguishing agent to achieve a continuous suppression effect, the second function is to reduce the mechanical impact of the external environment on the agent and cause damage to the agent, and the third function is not to be mistakenly triggered by adjacent fire extinguishing agents.

[0053] like Figure 5 As shown, the high temperature self-triggered fire extinguishing agent block is located directly above the battery cell pressure relief valve. The block arrangement of the fire extinguishing agent block is to trigger the corresponding fire extinguishing agent only at the corresponding thermal runaway battery cell position to achieve the purpose of multiple suppression.

[0054] The main components of fire extinguishing agents are potassium nitrate, strontium nitrate, linear phenolic resin, basic magnesium carbonate, etc. Its working principle is as follows: through the endothermic decomposition and cooling effect of the fire extinguishing agent and the chemical inhibition of the gas phase and solid phase, they work synergistically to achieve the suppression of combustion.

[0055] (1) Cooling and fire extinguishing effect of endothermic decomposition

[0056] The cooling effect of fire extinguishing agents mainly relies on the endothermic decomposition of metal oxides and carbonates. The heat released by any fire in a short period of time is limited. If the solid particles in the fire extinguishing agent can absorb part of the heat released by the fire source in a short period of time, the temperature of the flame will be reduced, and the heat radiated to the combustion surface and used to crack the already gasified combustible molecules into free radicals will be reduced, and the combustion reaction will be inhibited to a certain extent.

[0057] (2) Gas phase chemical inhibition

[0058] Under the action of heat, the gasified metal ions such as Sr, K, Mg or cations that have lost electrons decomposed by the fire extinguishing agent exist in the form of steam, and undergo multiple chain reactions with the active groups H·, ·OH and O· in the combustion. Taking Sr as an example:

[0059] Sr+2·OH→Sr(OH)2

[0060] Sr+O·→SrO

[0061] Sr(OH)2+2H·→Sr+2H2O

[0062] This process is repeated many times, and the active groups in combustion are consumed in large quantities, the concentration continues to decrease, and combustion is suppressed.

[0063] (3) Solid-phase chemical inhibition

[0064] The solid particles in the fire extinguishing agent can absorb the chain reaction intermediates OH, H and O, and catalyze them to reconstitute stable molecules, thereby interrupting the branch chain reaction of the combustion process. Take K as an example:

[0065] K2O(s)+2H(g)→2KOH(s)

[0066] KOH(s)+OH(g)→KO(s)+H2O(g)

[0067] K2O(s)+O(g)→2KO(s)

[0068] KO(s)+H(g)→KOH

[0069] In the above-mentioned fire extinguishing effect, several fire extinguishing mechanisms interact and work synergistically, but the gas transmission effect and the heat absorption and cooling effect of metal oxides or carbonates only play auxiliary effects, and the main fire extinguishing effect still relies on the chemical inhibition of gas and solid phases.

[0070] At the same time, the fire extinguishing dosage of each separated sub-area is set according to S (fire extinguishing dosage g) = V (remaining space volume under the vehicle m3) * ρ (fire extinguishing design density 140~180g / m3), so that the ejected materials of each triggered fire extinguishing agent reaction can cover the entire space under the vehicle, so as to ensure that the space under the vehicle is always in an inert suppression environment during thermal runaway of the battery cell, making the passenger compartment safer.

[0071] Finally, it should be noted that the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making any creative work are within the scope of protection of the present application.

[0072] The above only describes some exemplary embodiments of the present invention by way of illustration. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A high-temperature self-triggering fire extinguishing device for an electric vehicle battery pack, characterized in that: It is installed between the battery pack cover and the chassis sheet metal. The high-temperature self-triggered fire extinguishing device includes: A fire extinguishing agent fixing frame, which is fixed to the chassis sheet metal and faces the battery pack, A heat-insulating flame-retardant sleeve fixed to the fire-extinguishing agent fixing frame, a fire extinguishing agent contained in the heat-insulating flame-retardant sleeve, The heat-sensitive wire is disposed in the fire extinguishing agent and is exposed to the fire extinguishing agent at a side facing the battery pack.

2. A high temperature self-triggering fire extinguishing device for an electric vehicle battery pack according to claim 1, characterized in that: The fire extinguishing agent block is located directly above the pressure relief valve of the battery pack.

3. A high temperature self-triggering fire extinguishing device for an electric vehicle battery pack according to claim 1, characterized in that: The fire extinguishing agent fixing frame is a grid structure covering the battery pack.

4. A high temperature self-triggering fire extinguishing device for an electric vehicle battery pack according to claim 3, characterized in that: The grid structure includes a plurality of rectangular grids in an array.

5. A high temperature self-triggering fire extinguishing device for an electric vehicle battery pack according to claim 1, characterized in that: The high-temperature self-triggered fire extinguishing device is detachably connected to the chassis of the electric vehicle via bolts.

6. A high temperature self-triggering fire extinguishing device for an electric vehicle battery pack according to claim 1, characterized in that: The heat-insulating flame-retardant sleeve is a door-shaped structure.

7. A high temperature self-triggering fire extinguishing device for an electric vehicle battery pack according to claim 6, characterized in that: The gate-shaped structure includes a pair of horizontal side walls and a vertical wall connecting the side walls.

8. A high temperature self-triggering fire extinguishing device for an electric vehicle battery pack according to claim 1, characterized in that: The fire extinguishing agent is filled in the heat-insulating flame-retardant sleeve.

9. A high temperature self-triggering fire extinguishing device for an electric vehicle battery pack according to claim 1, characterized in that: The heat-sensitive wire is embedded in the fire extinguishing agent and is exposed to the fire extinguishing agent at a side facing the battery pack.

10. A high temperature self-triggering fire extinguishing device for an electric vehicle battery pack according to claim 1, characterized in that: The high-temperature self-triggering fire extinguishing device for an electric vehicle battery pack has a symmetrical structure.

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