Miniature fire extinguishing device for electrical circuit of energy storage system and manufacturing method of miniature fire extinguishing device

Abstract

The invention provides a miniature fire extinguishing device for an electrical circuit of an energy storage system and a manufacturing method thereof.The miniature fire extinguishing device comprises a fire extinguishing glass ball and a clamp electrically connected below the fire extinguishing glass ball, the fire extinguishing glass ball comprises an outer pipe and an inner pipe which are of an integrated structure, a protective layer is formed between the inner pipe and the outer pipe, the interior of the inner pipe is used for storing a fire extinguishing agent, and a conductive coating is arranged on the outer side of the outer pipe; the two ends of the outer pipe are each of a hemispherical structure. According to the micro fire extinguishing device for the electrical circuit of the energy storage system and the manufacturing method of the micro fire extinguishing device, the micro fire extinguishing device is installed in an electrical system in a lithium ion battery energy storage power station, fire disasters of the electrical system are accurately extinguished in a targeted mode, and the problem that fire disasters are caused by short circuit and overcurrent of an electrical communication circuit of a lithium ion battery is solved.

Description

Technical Field

[0001] The present invention belongs to the field of fire protection of energy storage systems, and in particular relates to a miniature fire extinguishing device for electrical circuits of energy storage systems and a manufacturing method thereof. Background Art

[0002] Energy storage is an important part of the energy internet and a key technology to support the construction of a new power system. Electrochemical energy storage based on lithium-ion batteries is highly favored due to its advantages such as fast response speed, good expansion performance, and flexible regulation. However, in recent years, fire and explosion accidents in energy storage power stations caused by thermal runaway of lithium-ion batteries have occurred frequently, causing serious casualties and property losses, and have become the main technical bottleneck restricting the safe and healthy development of the battery energy storage industry. Among the causes of energy storage fire accidents, in addition to accidents caused by thermal runaway of batteries, fires caused by short circuits and overcurrents in electrical (communication) lines often occur, so we are currently developing fire prevention and extinguishing products for electrical systems. Summary of the invention

[0003] In view of this, the present invention aims to propose a miniature fire extinguishing device for electrical circuits of an energy storage system to solve the problem of fires caused by short circuits and overcurrents in the electrical communication circuits of lithium-ion batteries.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows: A miniature fire extinguishing device for an electrical circuit of an energy storage system comprises a fire extinguishing glass ball and a clamp electrically connected thereto. The fire extinguishing glass ball comprises an outer tube and an inner tube of an integral structure, a protective layer is formed between the inner tube and the outer tube, the interior of the inner tube is used to store a fire extinguishing agent, a conductive coating is provided on the outside of the outer tube, and both ends of the outer tube are hemispherical.

[0005] Furthermore, the outer tube includes an integrally structured head, middle and tail, the tail and head are both hemispherical solid molten glass, the middle is a cylindrical structure, and the head is a hemispherical structure.

[0006] Furthermore, the inner tube is a hollow cylindrical structure with a capillary tube at one end, and a conical structure is provided between the capillary tube and the hollow cylinder.

[0007] Furthermore, the fire extinguishing agent in the inner tube is perfluorohexanone.

[0008] Furthermore, the conductive coating is tin-plated on a chromium-plated layer.

[0009] Furthermore, the clamp is provided with four guide posts for clamping the fire-extinguishing glass ball, each guide post is provided with a tin-plated layer inside, and two conductive feelers are provided under the clamp.

[0010] Compared with the prior art, the miniature fire extinguishing device for the electrical circuit of the energy storage system described in the present invention has the following advantages: (1) The micro fire extinguishing device for the electrical circuit of the energy storage system described in the present invention is used to be installed in the internal electrical system of the lithium-ion battery energy storage power station to achieve targeted and accurate extinguishing of electrical system fires, solving the problem of fires caused by short circuits and overcurrents in the electrical communication lines of lithium-ion batteries.

[0011] (2) The miniature fire extinguishing device for the electrical circuit of the energy storage system described in the present invention has a simple structure and is subjected to stress in an optimal manner by reinforcing the ends, thereby avoiding adverse shear and bending stresses in the glass.

[0012] Another object of the present invention is to provide a method for manufacturing a miniature fire extinguishing device for electrical circuits of an energy storage system, so as to solve the problem of fire caused by short circuit and overcurrent in the electrical communication circuits of lithium-ion batteries.

[0013] To achieve the above object, the technical solution created by the present invention is implemented as follows: A method for manufacturing a miniature fire extinguishing device for an electrical circuit of an energy storage system comprises the following steps: S1. Make the pipe body; S2, liquid vacuum filling; S3, tip sealing; S4, coating the outer tube with a conductive coating; S5. Place the fire extinguishing glass ball into the fixture and ensure electrical connection.

[0014] Furthermore, the specific method for making the tube body in S1 is: one end of a hollow glass tube with a diameter of 5 mm is melted at 600°C. This high temperature process forms a uniform hemispherical glass melt. The other end of the glass tube is pulled while being ablated at high temperature. While the hemispherical glass melt is formed, a capillary is reserved for filling the fire extinguishing agent.

[0015] Furthermore, the method of vacuum filling the liquid in S2 is: S21, connecting the capillary tube to an external vacuum system so that the inner tube reaches a set vacuum degree; S22. Precool the working liquid to -20°C before filling. The liquid is injected into the inner tube through the filling needle and filled alternately with positive and negative pressures. The filled product is immediately transferred to a low-temperature transfer box.

[0016] Furthermore, the specific method for sealing the tip in S3 is: compounding heptafluoro-3-methoxypropane on the basis of degassing by negative pressure low-temperature distillation method for distillation, cooling the glass ball to be sealed to -10°C before sealing the tip, and continuously cooling the glass ball during the sealing process.

[0017] The manufacturing method of the miniature fire extinguishing device for the electrical circuit of the energy storage system has the same advantages as the above-mentioned miniature fire extinguishing device for the electrical circuit of the energy storage system over the prior art, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings: Figure 1 A schematic diagram of a miniature fire extinguishing device for an electrical circuit of an energy storage system according to an embodiment of the present invention; Figure 2 It is a side view of the fire extinguishing glass ball described in an embodiment of the present invention.

[0019] Description of reference numerals: 1-outer tube; 11-head; 12-tail; 2-inner tube; 21-capillary; 3-clamp; 31-guide column; 32-conductive layer. DETAILED DESCRIPTION

[0020] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0021] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0022] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0023] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0024] A miniature fire extinguishing device for an electrical circuit of an energy storage system, as shown in the figure, includes a fire extinguishing glass ball and a clamp 3 electrically connected thereto, the fire extinguishing glass ball includes an outer tube 1 and an inner tube 2 of an integral structure, a protective layer is formed between the inner tube 2 and the outer tube 1, the inner tube 2 is used to place a fire extinguishing agent, a conductive coating is provided on the outer side of the outer tube 1, and both ends of the outer tube 1 are hemispherical structures. Specifically, the fire extinguishing glass ball adopts a bone-like structure.

[0025] The outer tube 1 includes an integral head 11, a middle part and a tail 12. The tail 12 is a hemispherical solid glass melt, the middle part is a cylindrical structure, the head 11 is a hemispherical structure, and the spherical structures arranged at both ends are conducive to dispersing the stress of the fire extinguishing glass ball.

[0026] The inner tube 2 is a hollow cylindrical structure with a capillary 21 at one end. Preferably, a conical structure is provided between the capillary 21 and the hollow cylinder to facilitate the injection of liquid into the inner tube 2. This structure gradually opens from the outside to the inside, making it very easy for liquid to enter the inner tube 2, greatly improving work efficiency.

[0027] The liquid in the inner tube 2 is perfluorohexanone.

[0028] The conductive coating is tin-plated on the chromium-plated layer, which can solve the problems of difficulty in directly plating tin on the surface of the glass ball and insufficient chromium conductivity.

[0029] The clamp 3 is provided with four guide columns 31 for clamping the fire extinguishing glass ball. A conductive layer 31 is provided inside each guide column 31. Preferably, the conductive layer is a tin-plated layer to ensure the conductivity between the clamp 3 and the fire extinguishing glass ball. Two conductive antennae are also provided under the clamp 3 to facilitate the installation of electrical circuits.

[0030] This solution mainly targets the technical difficulties in extinguishing initial fires in the electrical circuits of lithium-ion battery energy storage systems. It overcomes key technologies such as the mixing and compounding of high-dielectric and non-corrosive fire extinguishing agents, and the molding of temperature-sensitive glass balls at multiple nominal operating temperatures. It develops passive micro-temperature-sensing fire detection and extinguishing devices for the internal electrical systems of lithium-ion battery energy storage power stations, and achieves targeted and accurate extinguishing of electrical system fires.

[0031] A method for manufacturing a miniature fire extinguishing device for an electrical circuit of an energy storage system comprises the following steps: S1. Make the tube body One end of a hollow glass tube with a diameter of 5 mm is melted at 600°C. This high temperature process forms a uniform hemispherical glass melt as the tail 12. The other end of the glass tube is pulled while being ablated at high temperature. While forming the hemispherical glass melt, an extremely fine capillary 21 is reserved for filling the fire extinguishing agent. The fire extinguishing glass ball adopts a bone-like structure design. This design strengthens the end to bear the force in the best way, avoiding adverse shear and bending stresses in the glass. This structural design forms the high strength of the sphere, and the special filling liquid ensures a fast response time.

[0032] S2. Liquid vacuum filling The filling of fire extinguishing agent adopts the principle of vacuum filling technology. The capillary 21 pipeline is connected to a vacuum system. The air in the inner tube 2 is extracted through the negative pressure hole to make the tube reach a certain vacuum degree. Under the vacuum state, the liquid is injected into the inner tube 2 through the filling needle until the filling is completed. The filling needle is usually controlled by the filling drive mechanism, which can accurately control the filling position and depth. After the filling is completed, the fire extinguishing glass ball is sealed (melted at high temperature) to maintain the vacuum state in the tube and prevent liquid leakage. When the vacuum degree is -0.07, the boiling point of perfluorohexanone is 15℃; when the vacuum degree is -0.08, the boiling point of perfluorohexanone is 3.8℃, so the temperature control during the filling process must be very strict, otherwise it is very easy to cause dissatisfaction of filling. In this study, the working liquid in the inner tube 2 is precooled to -20℃ before filling, and the traditional negative pressure filling is changed to positive and negative pressure alternating filling, and the temperature is strictly controlled during the filling process. The filled product is immediately transferred to a low-temperature transfer box to minimize the impact of the volatilization of the working liquid. This filling method can increase the filling speed, prevent the volatilization of the fire extinguishing agent, and avoid filling containers with cracks or gaps.

[0033] S3, tip sealing In order to make the glass ball meet the nominal action temperature and response time, it is necessary to seal the tip in an oil bath at a specific temperature. In this study, since the fire extinguishing agent we used was perfluorohexanone, the high volatility of perfluorohexanone makes it easier for the product to lose working liquid before the tip is sealed, resulting in inconsistent action temperature of the product after tip sealing. The boiling point of perfluorohexanone is 49.2℃ at standard atmospheric pressure, so the traditional degassing process (water bath heating degassing) can only produce products with an action temperature within the range of 60℃, which cannot meet its high action temperature requirements. The heat of evaporation of perfluorohexanone is only 1 / 25 of that of water, while the vapor pressure is 25 times that of water. This characteristic makes the glass ball very easy to absorb heat and vaporize during the tip sealing process, forming a jet airflow at the tip, resulting in tip sealing failure. Because at this temperature, this liquid expands as the temperature rises when a fire occurs, causing the pressure inside the ball to increase until the glass ball bursts into small fragments at the specified action temperature. To this end, this study compounded heptafluoro-3-methoxypropane and other reagents for distillation based on the negative pressure low-temperature distillation method to remove bubbles. At the same time, the glass ball to be sealed was cooled to -10℃ before sealing, and the glass ball was continuously cooled during the sealing process.

[0034] S4. Apply conductive coating Since the surface of the fire-extinguishing glass ball is a smooth curved surface, and the use of the developed electrical circuit micro-fireproof product is exposed to the air, the conductive coating must meet the characteristics of strong adhesion, high conductivity, corrosion resistance, and good stability. This study innovatively attempts to change the physical and chemical properties of the glass surface by covering a layer of other metals or alloys on the metal surface, enhancing its corrosion resistance, hardness, and wear resistance, while giving it electrical conductivity and thermal conductivity. Many metals are susceptible to oxidation and corrosion in natural environments or specific working conditions. For example, iron is prone to rust in a humid environment, which not only affects the aesthetics of the product, but more importantly, it will reduce the performance and safety of the product. By plating a layer of metal with better corrosion resistance on the metal surface, such as zinc, chromium, etc., the substrate can be effectively isolated from direct contact with the external corrosive medium, thereby extending the service life of the product. Chromium has a low electrical conductivity of 0.0774*10^6 / (cm*Ω) and strong adhesion, which can significantly improve the corrosion resistance and wear resistance of the metal, allowing the product to maintain a good working condition for a long time in harsh environments. This study intends to adopt a technical route of first plating chrome on the surface of the glass ball and then plating tin on the chromium layer, aiming to solve the problems of difficulty in directly plating tin on the surface of the glass ball and insufficient chromium conductivity.

[0035] In terms of technical feasibility, chrome plating and tin plating are two mature surface treatment technologies. Chrome plating can provide a hard, corrosion-resistant protective layer for glass balls, and can improve the bonding strength between the glass surface and subsequent coatings. Tin plating on the chrome layer can utilize the good electrical conductivity of tin to improve the electrical conductivity of the overall coating. The electrical conductivity of the tin coating is high, which can meet the needs of electrical conductivity. At the same time, the tin layer also has good welding performance and corrosion resistance.

[0036] In terms of practical operation, the double-layer plating process requires precise control of parameters such as plating thickness, temperature, pH value, etc. to ensure the uniformity and quality of the plating. In addition, after tin plating, the glass ball needs to be post-processed, including passivation treatment, to increase corrosion resistance and protection.

[0037] S5. Place the fire extinguishing glass ball into the fixture 3 and ensure electrical connection.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A miniature fire extinguishing device for electrical circuits of an energy storage system, characterized in that: The invention comprises a fire extinguishing glass ball and a clamp electrically connected thereto. The fire extinguishing glass ball comprises an outer tube and an inner tube of an integral structure. A protective layer is formed between the inner tube and the outer tube. The interior of the inner tube is used to store fire extinguishing agent. A conductive coating is provided on the outside of the outer tube. Both ends of the outer tube are hemispherical.

2. A miniature fire extinguishing device for electrical circuits of an energy storage system according to claim 1, characterized in that: The outer tube comprises an integrally structured head, middle and tail, the tail and the head are both hemispherical solid glass melts, the middle is a cylindrical structure, and the head is a hemispherical structure.

3. A miniature fire extinguishing device for electrical circuits of an energy storage system according to claim 1, characterized in that: The inner tube is a hollow cylindrical structure with a capillary tube at one end, and a cone structure is also arranged between the capillary tube and the hollow cylinder.

4. A miniature fire extinguishing device for electrical circuits of an energy storage system according to claim 1, characterized in that: The fire extinguishing agent in the inner tube is perfluorohexanone.

5. A miniature fire extinguishing device for electrical circuits of an energy storage system according to claim 1, characterized in that: The conductive coating is tin-plated on a chromium-plated layer.

6. A miniature fire extinguishing device for electrical circuits of an energy storage system according to claim 1, characterized in that: The clamp is provided with 4 guide columns for clamping the fire extinguishing glass ball, each guide column is provided with a conductive layer inside, and two conductive tentacles are also provided under the clamp.

7. A method for manufacturing a miniature fire extinguishing device for an electrical circuit of an energy storage system according to any one of claims 1 to 6, characterized in that: The steps include: S1. Make the pipe body; S2, liquid vacuum filling; S3, tip sealing; S4, coating the outer tube with a conductive coating; S5. Place the fire extinguishing glass ball into the fixture and ensure electrical connection.

8. The method for manufacturing a miniature fire extinguishing device for an electrical circuit of an energy storage system according to claim 7, characterized in that: The specific method for making the tube body in S1 is: melt one end of a hollow glass tube with a diameter of 5 mm at 600°C. This high-temperature process forms a uniform hemispherical glass melt. The other end of the glass tube is pulled while being ablated at high temperature. While the hemispherical glass melt is formed, a capillary is reserved for filling the fire extinguishing agent.

9. The method for manufacturing a miniature fire extinguishing device for an electrical circuit of an energy storage system according to claim 7, characterized in that: The method of vacuum filling of liquid in S2 is: S21, connecting the capillary tube to an external vacuum system so that the inner tube reaches a set vacuum degree; S22. Precool the working liquid to -20°C before filling. The liquid is injected into the inner tube through the filling needle and filled alternately with positive and negative pressures. The filled product is immediately transferred to a low-temperature transfer box.

10. The method for manufacturing a miniature fire extinguishing device for an electrical circuit of an energy storage system according to claim 7, characterized in that: The specific method of tip sealing in S3 is: compound heptafluoro-3-methoxypropane on the basis of vacuum low-temperature distillation method to remove bubbles and perform distillation, and at the same time cool the glass ball to be sealed to -10°C before sealing, and continue to cool the glass ball during the tip sealing process.

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