Gas circuit breaker

Abstract

To reduce wear of an insulation nozzle.SOLUTION: A gas circuit breaker (100) includes a first contactor (10), and an insulation nozzle (50). An inside part (51) of the insulation nozzle (50) includes a porous insulation material (511), and an ablating resin (513) which is filled into the inside of a pore (512) of the porous insulation material (511).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a gas circuit breaker. [Background technology]

[0002] Patent Document 1 discloses a gas circuit breaker that has a nozzle with a porous inner surface made of an insulating material such as fluororesin and the rest of the nozzle made of a high-density insulating material, and that can prevent damage to the inner surface of the nozzle by releasing gas expanded by an arc from the porous part to the outside. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-101755 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional technology, the nozzle itself is made of fluororesin, and therefore the fluororesin melts due to the heat radiation of the arc that occurs when the gas is shut off, and the inner surface of the nozzle is easily worn away.

[0005] There is a demand for a gas circuit breaker that can reduce wear on the insulating nozzle. [Means for solving the problem]

[0006] In order to solve the above problems, a gas circuit breaker according to one embodiment of the present invention comprises a first contactor and an insulating nozzle through which the first contactor can be inserted, and an inner portion of the insulating nozzle contains a porous insulating material and an evaporative resin filled inside the pores of the porous insulating material. [Effects of the Invention]

[0007] According to one aspect of the present invention, wear on the insulating nozzle can be reduced. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view of a gas circuit breaker according to an embodiment of the present invention, cut in the axial direction. [Figure 2] 2 is a cross-sectional view taken along the line II-II in FIG. 1 and a schematic enlarged view of a portion of the cross-sectional view. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Embodiment] Fig. 1 is a cross-sectional view of a gas circuit breaker 100 according to this embodiment taken along the axial direction. Fig. 1 shows the gas circuit breaker 100 in an energized state. In Fig. 1, the axis of the gas circuit breaker 100 is indicated as axis P. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1.

[0010] The gas circuit breaker 100 is a device that interrupts a current in a power system through which a large current flows by spraying insulating gas onto an arc that occurs when two contacts are separated to interrupt the current. As shown in Fig. 1, the gas circuit breaker 100 comprises a first contactor 10, a second contactor 20, a third contactor 30, an operating rod 21, a puffer cylinder 40, a puffer piston 41, and an insulating nozzle 50. It is assumed here that all of these components are arranged concentrically about an axis P.

[0011] The first contactor 10 is a cylindrical conductor. The first contactor 10 is movable relative to the second contactor 20 in the direction of extension of the axis P, and is movable at least from a contact position with the second contactor 20 to a position where the insulating nozzle 50 is separated from the first contactor 10. Similarly, the second contactor 20 may be movable relative to the first contactor 10. For convenience in the following description, the direction in which the first contactor 10 approaches the second contactor 20 will be referred to as the first direction, and the direction in which the first contactor 10 moves away from the second contactor 20 will be referred to as the second direction. The first direction and the second direction are both parallel to the axis P.

[0012] The second contactor 20 is a cylindrical conductor. One end of the second contactor 20 contacts the first contactor 10, and the other end is connected to an operating rod 21. As shown in FIG. 1 , in a conducting state, the first contactor 10 is located inside the opening of the second contactor 20, and the inner surface of one end of the second contactor 20 and the outer surface of the first contactor 10 are in contact with each other. The second contactor 20 may have any number of slits of any length in the axial direction to enable elastic contact with the first contactor 10.

[0013] The operating rod 21 is a cylindrical conductor. An opening on the second direction side of the operating rod 21 and an opening on the first direction side of the second contactor 20 are connected to each other.

[0014] The insulating nozzle 50 is an insulator having a cylindrical portion through which the first contactor 10 can be inserted. The opening on the second direction side of the insulating nozzle 50 becomes wider as it approaches the second direction. In other words, the inner surface of the insulating nozzle 50 has an inclined surface 501 at the end in the second direction, the distance from the axis P increasing from the first direction to the second direction. The insulating nozzle 50 also has a through hole through which the first contactor 10 is inserted. The inner wall of the insulating nozzle that defines the through hole and faces the inserted first contactor 10 is referred to as the facing surface 502. In other words, the insulating nozzle 50 has an inner surface that includes the inclined surface 501 and the facing surface 502. The facing surface 502 and the outer surface of the first contactor 10 may contact each other or may have a small gap when the first contactor 10 passes through the through hole of the insulating nozzle 50. The opening on the first direction side of the insulating nozzle 50 is connected to the puffer cylinder 40. The gas circuit breaker 100 includes a gas path 61 formed between the insulating nozzle 50 and the second contactor 20 .

[0015] The insulating nozzle 50 has an inner portion 51 including an opposing surface 502 and an outer portion 52 including an outer surface 503 of the insulating nozzle 50. The inner portion 51 may be a portion of the insulating nozzle 50 whose distance from the opposing surface 502 is equal to or less than half the distance from the opposing surface 502 to the outer surface 503. The inner portion 51 may be an inner portion of the insulating nozzle 50 at a position corresponding to a throat portion where the opening is smaller. The inner surface of the inner portion 51 may include a portion of the inclined surface 501. The inner portion 51 may have a cylindrical shape. The inner portion 51 includes a portion 511 having a plurality of pores 512 and an ablative resin 513 filled inside the pores 512. The pores 512 in the present disclosure may be voids in the porous insulating material 511.

[0016] The porous insulating material 511 includes, for example, ceramic. The ceramic may be, for example, an alumina (Al2O3) sintered body, an aluminum nitride sintered body, or a composite ceramic material containing alumina. Ceramics are highly wear-resistant materials. Furthermore, because ceramics have excellent heat resistance, ablation due to arcing hardly occurs. In other words, by using the porous insulating material 511 in the inner portion 51 of the insulating nozzle 50, wear on the insulating nozzle 50 can be reduced.

[0017] The ablative resin 513 includes a fluororesin. The ablative resin 513 may be a fluororesin. The fluororesin may be, for example, Teflon (registered trademark). Alternatively, the fluororesin may be, for example, PTFE (polytetrafluoroethylene), PAF (polytetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), or ETFE (ethylene-tetrafluoroethylene copolymer). Fluororesin has high insulating properties and is therefore a material traditionally used as an insulating nozzle material. Furthermore, although fluororesin is heat-resistant, it gradually ablates (evaporates) due to the heat of the arc. This ablation produces an ablation effect that contributes to cooling the arc or increasing the spray pressure, making the fluororesin a material that improves the arc's extinguishing properties.

[0018] In conventional insulating nozzles, the entire nozzle is made of fluororesin, which makes the insertion portion susceptible to wear, causing the diameter of the throat to expand. In the insulating nozzle 50 of the present disclosure, the inner portion 51 includes a porous insulating material 511 and an ablative resin 513 filled inside the porous insulating material 511. This reduces wear on the inner surface of the inner portion 51, particularly the opposing surface 502, and improves the arc extinguishing performance by the ablative resin 513. Furthermore, reducing wear on the inner diameter of the inner portion 51 increases the number of times the nozzle can be operated with high arc extinguishing performance.

[0019] In the insulating nozzle 50, not all pores 512 of the porous insulating material 511 need to be filled with the ablative resin 513. For example, the ratio of the volume of the ablative resin 513 to the total volume of all pores of the porous insulating material 511 constituting the inner portion 51 may be 50% or more, 75% or more, or 80% or more. Alternatively, 50% or more, 75% or more, or 80% or more of the pores of the porous insulating material 511 constituting the inner portion 51 may be filled with the ablative resin 513. Furthermore, the filling rate of the ablative resin 513 in one pore 512 may be 50% or more, 75% or more, or 80% or more. The higher the filling rate of the ablative resin 513 in the pores 512 of the porous insulating material 511 constituting the inner portion 51, the higher the ablation effect that can be obtained.

[0020] The porosity of the porous insulating material 511 may be 30% or more and 70% or less. If the porosity is lower than 30%, the content of the ablative resin 513 in the inner portion 51 will be low, making it difficult to obtain an ablation effect. Furthermore, if the porosity is higher than 70%, the strength of the inner portion 51 may be reduced. By making the porosity of the porous insulating material 511 30% or more and 70% or less, wear on the insulating nozzle 50 can be reduced and the arc extinguishing performance can be improved.

[0021] The radial thickness of the inner portion 51 may be 3 mm or more and 10 mm or less. The radial thickness of the inner portion 51 may preferably be 4 mm or more and 6 mm or less. Because the inner portion 51 includes pores 512, if the radial thickness is less than 3 mm, the strength of the inner portion 51 may be reduced. If the radial thickness is greater than 10 mm, the thickness of the outer portion (described later) becomes small, increasing the possibility of gas leaking through the insulating nozzle 50 to the outside of the insulating nozzle 50. By making the radial thickness 3 mm or more and 10 mm or less, the strength of the inner portion 51 can be ensured and the airtightness of the insulating nozzle 50 can be improved.

[0022] The outer portion 52 may be a portion of the insulating nozzle 50 whose distance from the outer surface 503 of the insulating nozzle 50 is equal to or less than half the distance from the outer surface 503 to the opposing surface 502. The outer portion 52 may be a portion located outside the inner portion 51 and including the outer surface 503 of the insulating nozzle 50. The outer portion 52 may have a cylindrical shape.

[0023] The outer portion 52 is formed of an insulating resin, and may be formed of, for example, a fluororesin. The material of the outer portion 52 may be the same material as the ablative resin 513 filled into the pores 512 of the inner portion 51. Fluorine-based resins generally have high insulating properties and high heat resistance, making them suitable as materials for the insulating nozzle 50. Fluorine-based resins also have excellent airtightness. The pores 512 of the inner portion 51 are filled with the ablative resin 513. However, if the ablative resin 513 ablates, the airtightness of the inner portion 51 decreases, and the insulating gas 60 may reach the outside of the inner portion 51. Forming the outer portion 52 from a fluororesin reduces the possibility of the insulating gas 60 leaking out through the insulating nozzle 50.

[0024] The puffer chamber 42 is defined by the puffer cylinder 40 and the puffer piston 41. The puffer chamber 42 stores an insulating gas 60 therein. The puffer cylinder 40 is connected to the operating rod 21. The puffer cylinder 40 has a through hole 62 in a part of the connection part with the operating rod 21. The materials of the puffer piston 41 and the puffer cylinder 40 are not particularly specified, but at least the puffer cylinder 40 is a conductor.

[0025] In FIG. 1, one puffer chamber 42 is defined by a pair of puffer cylinders 40 and a puffer piston 41. However, in another embodiment, two or more puffer chambers may be defined by two or more pairs of puffer cylinders. In these embodiments, the pressure of the insulating gas 60 is increased by mechanical compression. Meanwhile, in yet another embodiment, no piston is provided, and the pressure of the insulating gas 60 inside the puffer chamber 42 may be increased by thermal pressure increase. In yet another embodiment, thermal pressure increase and mechanical compression may be used in combination.

[0026] The third contactor 30 is a cylindrical conductor with a bottom and an opening at one end. The third contactor 30 connects to the first contactor 10 at the center of its bottom (on axis P). The inner diameter of the opening of the third contactor 30 corresponds to the outer diameter of the puffer cylinder 40, and the inner surface of the third contactor 30 and the outer surface of the puffer cylinder 40 are in contact with each other. At this time, the third contactor 30 elastically contacts the puffer cylinder 40. Therefore, the third contactor 30 has an arbitrary number of slits of any length in the axial direction. When interrupting electrical conduction, even if the puffer cylinder 40 and the third contactor 30 are separated, the first contactor 10 and the second contactor 20 remain connected. Therefore, no arc occurs between the puffer cylinder 40 and the third contactor 30.

[0027] The gas path 61 is a space formed in the gap between the insulating nozzle 50 and the second contact 20. An insulating gas 60 can flow between the gas path 61 and the puffer chamber 42 via a through hole 62. The insulating nozzle 50, the second contact 20, the operating rod 21, and the puffer cylinder 40 can move together in the axial direction. The first contact 10, the third contact 30, and the puffer piston 41 can move together in the axial direction. Therefore, as the first contact 10 and the second contact 20 move apart, the insulating gas 60 in the puffer chamber 42 is compressed. This allows the insulating gas 60 to be sprayed against the arc that occurs when the first contact 10 and the second contact 20 move apart.

[0028] [Procedure for creating insulating nozzle 50] An example of a procedure for producing the insulating nozzle 50 according to this embodiment will be described below. The insulating nozzle 50 may be produced, for example, as follows.

[0029] First, the inner portion 51 is made of the porous insulating material 511. For example, if the porous insulating material 511 is ceramic, the ceramic material containing alumina, a binder, and the like is formed into a cylindrical shape having an inclined surface on the inner surface of one end, and then sintered to make the inner portion 51 made of the porous insulating material 511. Alternatively, the inner portion 51 may be made by carving out the porous insulating material 511.

[0030] Next, the inner part 51 is placed in a mold having the shape of the insulating nozzle 50, and heated and melted volatilizable resin 513 is poured into it, thereby filling the pores 512 with the volatilizable resin 513 and forming the outer part 52.

[0031] 〔summary〕 A gas circuit breaker according to aspect 1 of the present invention comprises a first contactor and an insulating nozzle through which the first contactor can be inserted, and an inner portion of the insulating nozzle includes a porous insulating material and an evaporative resin filled inside the pores of the porous insulating material.

[0032] A gas circuit breaker according to a second aspect of the present invention is the gas circuit breaker of the first aspect, wherein the porous insulating material includes ceramic.

[0033] A gas circuit breaker according to a third aspect of the present invention is the gas circuit breaker of the first or second aspect, wherein the outer portion of the insulating nozzle contains a fluorine-based resin.

[0034] A fourth aspect of the present invention relates to the gas circuit breaker of any one of the first to third aspects, wherein the ablative resin includes a fluorine-based resin.

[0035] A gas circuit breaker according to a fifth aspect of the present invention is the gas circuit breaker of any one of the first to fourth aspects, wherein the porosity of the porous insulating material is 30% or more and 70% or less.

[0036] A sixth aspect of the present invention is directed to the gas circuit breaker of any one of the first to fifth aspects, wherein the radial thickness of the inner portion is 3 mm or more and 10 mm or less.

[0037] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment. [Explanation of symbols]

[0038] 100 Gas Circuit Breaker 10 First contact 20 Second contact 50 Insulated nozzle 51 Inner part 52 Outer part 511 Porous insulating materials 512 Stoma 513 Absorbable Resin

Claims

1. A first contactor; an insulating nozzle through which the first contact can be inserted, A gas circuit breaker, wherein the inner portion of the insulating nozzle includes a porous insulating material and an ablative resin filled inside the pores of the porous insulating material.

2. The gas circuit breaker of claim 1 , wherein the porous insulating material comprises a ceramic.

3. The gas circuit breaker according to claim 1 , wherein the outer portion of the insulating nozzle comprises a fluororesin.

4. The gas circuit breaker according to claim 1 , wherein the ablative resin includes a fluorine-based resin.

5. 2. The gas circuit breaker according to claim 1, wherein the porosity of the porous insulating material is 30% or more and 70% or less.

6. 2. The gas circuit breaker according to claim 1, wherein the radial thickness of the inner portion is 3 mm or more and 10 mm or less.

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