Structure and method for forced arc extinguishing through electric effect of isolated fuse wire gasification activation liquid

Abstract

The invention relates to the technical field of emergency protection devices, in particular to an isolation type fuse wire gasification activation liquid electric effect forced arc extinguishing structure which comprises an insulation shell, arc extinguishing liquid filled in the insulation shell, an isolation pipe arranged in the arc extinguishing liquid and a fuse wire arranged in the isolation pipe in a penetrating mode. The isolating tube is made of an insulating and fragile material and is used for isolating the fuse wire from the arc extinguishing liquid; when short-circuit current flows through the fuse wire, the fuse wire is quickly gasified and generates metal explosion expansive force, and the isolation tube is broken and disintegrated under the action of the expansive force, so that electric arc generated by gasification of the fuse wire is in contact with arc extinguishing liquid; the arc extinguishing liquid is used for wrapping metal particles after the fuse wire is gasified, cutting off conductive channels among the particles, and improving the arc extinguishing voltage through the liquid-electric effect. Meanwhile, the invention further provides an arc extinguishing method based on the structure. According to the invention, the gasification time of the fuse wire can be shortened, and electric arc reignition can be effectively inhibited.

Description

Technical Field

[0001] This invention relates to the field of emergency protection device technology, specifically to a structure and method for forced arc extinguishing by vaporization activation of the liquid electro-hydraulic effect in an isolated fuse. Background Technology

[0002] The core structure of a traditional fusible fuse consists of a fuse wire encapsulated in an air-insulated tube. Its working principle relies on the fuse wire vaporizing upon heating to interrupt the current. However, a key drawback exists in practical applications: the metal particles generated when the fuse wire vaporizes easily adhere to the inner wall of the tube, forming a conductive path. This can cause the arc to reignite, resulting in a sharp drop in the arc-extinguishing voltage, making it unable to effectively interrupt the short-circuit current and thus losing its protective function.

[0003] To address the problem of arc reignition, existing technologies propose placing the fuse in an arc-extinguishing fluid to isolate metal particles through the liquid. However, the high specific heat capacity and strong heat dissipation of the arc-extinguishing fluid significantly inhibit the temperature rise of the fuse, prolonging its vaporization time and increasing the fault current sustaining time (i.e., the duration of the short-circuit current). This could potentially cause greater damage to circuit equipment and fail to meet the power system's requirement for "fast protection."

[0004] In summary, existing technologies face a contradiction between "preventing arc reignition" and "rapidly vaporizing to cut off current": either the air medium causes arc reignition, or the liquid medium prolongs the vaporization time. Therefore, there is an urgent need for an arc-extinguishing structure and method that can both shorten the vaporization time of the fuse and effectively suppress arc reignition, in order to improve the reliability and timeliness of circuit protection. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a structure and method for forced arc extinguishing by vaporization activation of the hydroelectric effect of an isolated fuse wire, so as to solve the problems mentioned in the background art.

[0006] In a first aspect, the present invention provides a structure for forced arc extinguishing via vaporization-activated hydroelectric effect of an isolated fuse wire, comprising an insulating shell, an arc-extinguishing liquid filled within the insulating shell, an isolation tube disposed within the arc-extinguishing liquid, and a fuse wire inserted within the isolation tube; the isolation tube is made of an insulating and brittle material and is used to isolate the fuse wire from the arc-extinguishing liquid; when a short-circuit current flows through the fuse wire, the fuse wire rapidly vaporizes and generates a metal explosive expansion force, and the isolation tube breaks apart under the action of the expansion force, so that the electric arc generated by the vaporization of the fuse wire comes into contact with the arc-extinguishing liquid; the arc-extinguishing liquid is used to encapsulate the metal particles after the fuse wire has vaporized, cut off the conductive channels between the particles, and increase the arc extinguishing voltage through the hydroelectric effect.

[0007] The first aspect of this invention has at least the following beneficial effects: Through the synergistic design of the isolation tube and the arc-extinguishing fluid, the problems of arc-extinguishing failure of traditional fuses and excessively long vaporization time of liquid immersion schemes are effectively solved. Firstly, the isolation tube isolates the fuse wire from the arc-extinguishing fluid, avoiding the liquid's heat dissipation which inhibits the temperature rise of the fuse wire, enabling rapid vaporization of the fuse wire, significantly shortening the fault current sustaining time, and improving the circuit protection response efficiency. Secondly, after the fuse wire vaporizes, the isolation tube breaks down, and the arc comes into contact with the arc-extinguishing fluid, activating the hydroelectric effect. At the same time, the arc-extinguishing fluid encapsulates the metal particles and cuts off their conductive channels, eliminating the conditions for arc reignition from the root. Thirdly, the rapid replacement of the arc-extinguishing fluid forms a strong insulating environment, transiently increasing the arc-extinguishing voltage, achieving an efficient transition from a short-circuit state to a strong insulating state, and comprehensively improving the reliability of arc extinguishing.

[0008] Compared with existing technologies, the present invention takes into account both melting speed and arc extinguishing effect, ensuring the safety and stability of circuit protection.

[0009] As a further improvement to the first aspect, the insulating housing is made of ceramic.

[0010] As a further improvement to the first aspect, the arc-extinguishing fluid has high insulation and rapid replacement characteristics, and is used to simultaneously replace the vaporized area of ​​the fuse wire after the isolation tube is disassembled, forming a transient transition from a short-circuit state to a strong insulation state.

[0011] As a further improvement to the first aspect, the arc-extinguishing fluid is transformer oil.

[0012] As a further improvement to the first aspect, the material of the isolation tube is glass or other fragile insulating material.

[0013] As a further improvement to the first aspect, the fuse is located at the center of the isolation tube.

[0014] Secondly, the present invention also provides an arc extinguishing method based on the above structure, comprising the following steps: S1. Isolating the fuse wire and the arc extinguishing liquid through an isolation tube to avoid the high heat dissipation of the arc extinguishing liquid suppressing the temperature rise of the fuse wire, so that the fuse wire can be rapidly vaporized under the action of short-circuit current; S2. The initial stage of the fuse wire vaporization generates a metal explosive expansion force, which breaks the isolation tube and brings the arc into contact with the arc extinguishing liquid; S3. The arc extinguishing liquid activates the arc extinguishing pressure through the electrohydraulic effect, and at the same time wraps the metal particles after the fuse wire vaporization, cutting off the conductive channels between the particles; S4. The arc extinguishing liquid synchronously replaces the vaporization area of ​​the fuse wire, forming a strong insulating environment and increasing the arc extinguishing voltage to suppress arc reignition. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a cross-sectional view of the structure of the isolated fuse wire vaporization-activated liquid electro-hydraulic effect forced arc extinguishing according to an embodiment of the present invention.

[0017] The correspondence between the labels and component names in the attached figures is as follows:

[0018] 1. Insulating shell; 11. Conductive electrode; 2. Isolation tube; 3. Fuse wire; 4. Arc extinguishing fluid; 5. Air. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] refer to Figure 1 The structure of the isolation fuse with vaporization activation liquid-electric effect forced arc extinguishing provided in this embodiment specifically includes an insulating shell 1, an arc extinguishing liquid 4 filled in the insulating shell 1, an isolation tube 2 disposed in the arc extinguishing liquid 4, and a fuse 3 passing through the isolation tube 2.

[0021] The insulating shell 1 is made of high-temperature resistant and high-strength ceramic material (epoxy resin or other insulating materials can also be selected). The interior is a sealed cavity, and conductive electrodes 11 (such as copper alloy electrodes) are set at both ends of the cavity for connecting the circuit.

[0022] The arc-extinguishing fluid 4 is filled inside the insulating shell 1. It is made of transformer oil with high insulation and low viscosity, with an insulation strength ≥100kV / mm and a viscosity ≤5mPa·s, to meet the requirements for rapid flow and replacement.

[0023] The isolation tube 2 is a glass tube (or quartz glass, fragile ceramics or other insulating and fragile materials) with an inner diameter of 1-3 mm and a wall thickness of 0.5-1 mm. It is vertically installed in the insulating shell 1 and immersed in the arc extinguishing liquid 4. Both ends are fixed to the conductive electrode 11 with insulating glue.

[0024] The fuse 3 is made of copper or silver alloy material, with a diameter of 0.1-0.5mm (adjusted according to the rated current), and is installed in the center of the isolation tube 2. Both ends are welded and fixed to the conductive electrode 11.

[0025] When a short circuit fault occurs in the circuit, the short circuit current flows through fuse 3, and the specific arc extinguishing process is as follows:

[0026] 1. Rapid vaporization stage of fuse wire 3:

[0027] The Joule heat generated by the short-circuit current causes the fuse 3 to heat up rapidly (because the isolation tube 2 isolates the fuse 3 from the arc extinguishing liquid 4, the high heat dissipation of the arc extinguishing liquid 4 cannot suppress the temperature rise of the fuse 3). The fuse 3 rapidly vaporizes within 1-3ms, generating metal vapor and accompanied by a violent explosive expansion force (about 10-50MPa).

[0028] 2. Isolation tube 2 disintegrates and comes into contact with arc-extinguishing liquid 4:

[0029] The explosive expansion force generated by the vaporization of the fuse 3 acts on the isolation tube 2 (glass tube). Due to the thin and fragile wall of the glass tube, it quickly breaks apart (fragment size ≤ 1mm). The electric arc generated by the vaporization of the fuse 3 (temperature about 5000-10000℃) is directly exposed to the arc extinguishing liquid 4.

[0030] 3. Activation by electrohydraulic effect and isolation by metal particles:

[0031] When the electric arc comes into contact with the arc-extinguishing liquid 4, the arc-extinguishing liquid 4 vaporizes instantaneously due to high temperature (vaporization pressure can reach 100-500MPa), activating the electrohydraulic effect to generate a high-voltage shock wave, which quickly extinguishes the electric arc; at the same time, the metal particles (particle size ≤1μm) formed by the vaporization of the fuse 3 are wrapped by the arc-extinguishing liquid 4, and the particles are completely isolated due to the insulation of the arc-extinguishing liquid 4, cutting off the conductive channel and preventing the power frequency follow current from reigniting.

[0032] 4. Transient transition in highly insulated environments:

[0033] The arc-extinguishing liquid 4 flows rapidly due to its low viscosity, simultaneously replacing the high-temperature area after the fuse wire 3 vaporizes (replacement time ≤ 2ms). The insulating shell 1 instantly changes from a conductive state during a short circuit to a strong insulating state (insulation strength is restored to the original level of the arc-extinguishing liquid 4). The arc-extinguishing voltage can be increased to 5-10 times that of the original air environment 5, completely suppressing arc reignition.

[0034] Through experimental verification, the structure of this embodiment was tested in an 800V DC circuit to test its short-circuit current interruption capability: the vaporization time of the fuse 3 was shortened from 15ms in the traditional liquid immersion scheme to 2ms, the insulation strength recovery time after arc extinguishing was ≤3ms, and no arc reignition was observed, which significantly improved the reliability of circuit protection.

[0035] The above description is merely 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 structure for forced arc extinguishing via vaporization activation of the hydroelectric effect of an isolated fuse wire, characterized in that, The device includes an insulating shell (1), an arc-extinguishing liquid (4) filled in the insulating shell (1), an isolation tube (2) disposed in the arc-extinguishing liquid (4), and a fuse (3) inserted in the isolation tube (2). The isolation tube (2) is made of an insulating and fragile material and is used to isolate the fuse (3) from the arc-extinguishing liquid (4). When a short-circuit current flows through the fuse (3), the fuse (3) rapidly vaporizes and generates a metal explosion expansion force. The isolation tube (2) is broken and disintegrated under the action of the expansion force, so that the electric arc generated by the vaporization of the fuse (3) comes into contact with the arc-extinguishing liquid (4). The arc-extinguishing liquid (4) is used to wrap the metal particles after the fuse (3) has vaporized, cut off the conductive channels between the particles, and increase the arc-extinguishing voltage through the electrohydraulic effect.

2. The structure according to claim 1, characterized in that, The insulating housing (1) is made of ceramic.

3. The structure according to claim 1, characterized in that, The arc-extinguishing liquid (4) has high insulation and rapid replacement characteristics. It is used to simultaneously replace the vaporization area of ​​the fuse wire (3) after the isolation tube (2) is disintegrated, forming a transient transition from a short-circuit state to a strong insulation state.

4. The structure according to claim 2, characterized in that, The arc-extinguishing fluid (4) is transformer oil.

5. The structure according to claim 1, characterized in that, The material of the isolation tube (2) is glass or other fragile insulating material.

6. The structure according to claim 1, characterized in that, The fuse (3) is located at the center of the isolation tube (2).

7. An arc-extinguishing method based on the structure described in any one of claims 1-6, characterized in that, Includes the following steps: S1. The fuse (3) is isolated from the arc extinguishing liquid (4) by the isolation tube (2), so as to avoid the high heat dissipation of the arc extinguishing liquid (4) from suppressing the temperature rise of the fuse (3) and make the fuse (3) vaporize rapidly under the action of short circuit current; S2. The initial stage of the vaporization of the fuse (3) generates a metal explosion expansion force, which breaks the isolation tube (2) and makes the electric arc come into contact with the arc extinguishing liquid (4); S3. The arc-extinguishing liquid (4) activates the arc-extinguishing pressure through the electrohydraulic effect, while simultaneously wrapping the metal particles after the fuse wire (3) has vaporized, cutting off the conductive channels between the particles. S4. The arc-extinguishing liquid (4) synchronously replaces the vaporization area of ​​the fuse (3) to form a strong insulating environment and increase the arc-extinguishing voltage to suppress arc reignition.

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