WO2022041829A1

WO2022041829A1 - Switching device and arc extinguishing chamber thereof

Info

Publication number: WO2022041829A1
Application number: PCT/CN2021/091847
Authority: WO
Inventors: 严旭; 马占峰; 路媛婧; 朱凯; 张文兵; 史俊; 赵培; 吕军玲; 马冲
Original assignee: 西安西电开关电气有限公司; 中国西电电气股份有限公司
Priority date: 2020-08-25
Filing date: 2021-05-06
Publication date: 2022-03-03
Also published as: CN112002605A; EP4207233A1; CN112002605B

Abstract

Disclosed are a switching device and an arc extinguishing chamber thereof. The arc extinguishing chamber comprises a first contact, a second contact, arcing rings provided between the first contact and the second contact and forming an arc gap, and a third contact moving axially between the first contact and the second contact. The arc distinguishing chamber further comprises: a circumferential thermal expansion chamber for collecting circumferential arc energy, the circumferential thermal expansion chamber circumferentially surrounding the arc gap between the arcing rings; and an axial thermal expansion chamber for collecting axial arc energy, wherein during an opening motion, the third contact moves from the first contact towards the second contact, the axial thermal expansion chamber is arranged on the side of the first contact away from the second contact, and the axial thermal expansion chamber is communicated with the arc gap. A portion of the generated arc energy enters the axial thermal expansion chamber by means of an axial flow, and the other portion of the arc energy enters the circumferential thermal expansion chamber from the arc gap by means of gas convection and radiation, such that all arc energy is utilized, thus avoiding waste and improving the arc energy utilization rate.

Description

A switchgear and its arc extinguishing chamber

This application claims the priority of the Chinese patent application filed on August 25, 2020 with the application number 202010866044.8 and the invention titled "a switchgear and its arc extinguishing chamber", the entire contents of which are incorporated herein by reference Applying.

technical field

The present invention relates to the field of switch technology, in particular to a switch device, and more particularly to an arc extinguishing chamber.

Background technique

The principle of self-energy arc extinguishing is that when the circuit breaker is opened, an arc will be generated between the fractures, and the arc temperature will be extremely high. At the same time, according to the energy formula W=I2Rt, it can be known that the arc carries huge energy. The designed arc extinguishing chamber uses the energy of the arc to increase the air pressure in the thermal expansion chamber, thereby establishing a pressure difference between the inside and outside of the thermal expansion chamber, so that when the current crosses zero, this pressure difference is used to quickly take away the thermally free molecules between the fractures. , to achieve the purpose of extinguishing the arc. This principle of using arc energy to extinguish the arc is called the principle of self-energy arc extinguishing.

The key to breaking the SF6 circuit breaker is to establish a high enough air pressure in the expansion chamber. There are various ways to establish air pressure. The commonly used ones are mechanical and self-energy. The mechanical type is to let the operating mechanism drive the piston in the pressure cylinder to move, and forcibly press the gas into the expansion chamber to achieve the purpose of pressurization. The circuit breaker, especially the circuit breaker for breaking ultra-high current, adopts the purely mechanical principle, which makes the volume of the circuit breaker and its supporting operating mechanism particularly huge, and such a product is not feasible in terms of economy and performance. At present, the principle of self-energizing arc extinguishing can greatly reduce the demand for the operation work of the mechanism to build pressure in the expansion chamber.

However, in the existing fixed-distance circuit breaker, when the opening movement starts, the moving contact moves along the axis, and when the moving contact moves to the side of the arc striking ring, the arc is fixed between the two arc striking rings. . The heating of the thermal expansion chamber by the arc generally passes through the gap between the two arc pilot rings (hereinafter referred to as the arc gap).

From a macroscopic point of view, the arc is equivalent to a charged conductor, which generates a magnetic field. In essence, an arc is a charged plasma that is affected by a magnetic field. Therefore, the arc will tend to shrink under the influence of its own magnetic field. The greater the breaking current, the greater the systolic pressure. Due to the effect of arc shrinkage, the heating of the thermal expansion chamber by the arc is mainly thermal radiation, and the arc gap is not large, so the efficiency of the arc heating the expansion chamber through the arc gap is not high.

Therefore, how to provide an arc extinguishing chamber to improve the utilization rate of arc energy is an urgent problem to be solved by those skilled in the art.

SUMMARY OF THE INVENTION

In view of this, the present invention provides an arc extinguishing chamber to improve the utilization rate of arc energy. In addition, the present invention also provides a switchgear with the above arc extinguishing chamber.

To achieve the above object, the present invention provides the following technical solutions:

An arc extinguishing chamber includes a first contact, a second contact, an arcing ring arranged between the first contact and the second contact and forming an arc gap, and an arcing ring on the first contact A third contact moving in the axial direction with the second contact, further comprising:

a circumferential thermal expansion chamber for collecting circumferential arc energy, the circumferential thermal expansion chamber circumferentially surrounding the arc gap between the arc rings;

an axial thermal expansion chamber for collecting axial arc energy, the third contact moves in the direction of the second contact from the first contact during the opening movement, and the axial thermal expansion chamber is arranged On a side of the first contact away from the second contact, the axial thermal expansion chamber communicates with the arc gap.

Preferably, the above-mentioned arc extinguishing chamber further comprises: a pressure cylinder for supplying high-pressure gas to the circumferential thermal expansion chamber, and the pressure cylinder communicates with the circumferential thermal expansion chamber.

Preferably, in the above-mentioned arc extinguishing chamber, the arcing ring includes a first arcing ring close to the first contact and a second arcing ring close to the second contact, the first arcing ring The arc gap is formed between the ring and the second arcing ring. After the third contact moves away from the first contact, the axial thermal expansion chamber passes through the inner circumference of the first contact. The formed space communicates with the arc gap.

Preferably, in the above-mentioned arc extinguishing chamber, the axial thermal expansion chamber is arranged symmetrically with respect to the center line of the third contact.

Preferably, in the above-mentioned arc extinguishing chamber, the axial thermal expansion chamber is a metal structure, and the inner surface is covered with a high temperature resistant material.

Preferably, in the above-mentioned arc extinguishing chamber, the end of the axial thermal expansion chamber away from the first contact has a pressure relief port, and the pressure relief port is provided with a pressure relief port for controlling the on-off of the pressure relief port When the pressure in the axial thermal expansion chamber reaches a preset value, the pressure relief valve is controlled to be turned on.

Preferably, in the above-mentioned arc extinguishing chamber, a deflector is provided on the end surface of the axial thermal expansion chamber away from the third contact, and the deflector is connected to the axial thermal expansion chamber from the free end. The end portion is gradually expanded, and the free end of the guide plate faces the third contact.

A switchgear includes an arc-extinguishing chamber, wherein the arc-extinguishing chamber is the arc-extinguishing chamber described in any one of the above.

In the arc extinguishing chamber provided by the invention, part of the generated arc energy enters the axial thermal expansion chamber by means of axial airflow, and another part of the arc energy enters the circumferential thermal expansion chamber through gas convection and radiation from the arc gap. In the above structure, the thermal expansion chambers are arranged in each possible flow direction of the arc, so that all the arc energy is utilized, waste is avoided, and the utilization rate of the arc energy is improved.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of an arc extinguishing chamber in an embodiment of the present invention.

detailed description

The invention discloses an arc extinguishing chamber to improve the utilization rate of arc energy. In addition, the present invention also discloses a switchgear with the above arc extinguishing chamber.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

As shown in FIG. 1 , the present application discloses an arc extinguishing chamber, at least one arcing system, the arcing system includes a first contact 2 , a second contact 7 , an arcing ring and a third contact 8 , in addition A circumferential thermal expansion chamber 5 and an axial thermal expansion chamber 3 are also included. The arcing ring is arranged between the first contact 2 and the second contact 7 and there is an arc gap B between the arcing ring, and the above-mentioned third contact 8 is between the first contact 2 and the second contact 7 And move along the axial direction of the first contact 2 and the second contact 7, and contact the first contact 2 and the second contact 7 in the closing position; when the third contact 8 is in the opening position, by The first contact 2 moves toward the second contact 7. During this process, after the third contact 8 is separated from the first contact 2, an arc is generated between the two, and part of the generated arc energy is generated by the axial airflow. way into the axial thermal expansion chamber 3, and another part of the arc energy enters the circumferential thermal expansion chamber 5 through the arc gap B through gas convection and radiation. In the above structure, the thermal expansion chambers are arranged in each possible flow direction of the arc, so that all the arc energy is utilized, waste is avoided, and the utilization rate of the arc energy is improved.

In a preferred embodiment, the arc extinguishing chamber further includes a pressure cylinder 6 for supplying high-pressure gas to the circumferential thermal expansion chamber 5 , and the pressure cylinder 6 communicates with the circumferential thermal expansion chamber 5 . Specifically, the pressure cylinder 6 is connected with the circumferential thermal expansion chamber 5 through several passages. Through the movement of the piston in the compression cylinder 6, the gas in the compression cylinder 6 is compressed to increase the pressure in the compression cylinder 6, and the high-pressure gas is pressed into the circumferential thermal expansion chamber 5 through the passage. The pressure cylinder has two main functions: first, before the third contact 8 and the first contact 2 are separated (ie before arcing), the gas in the pressure cylinder 6 is pressed into the circumferential thermal expansion chamber 5, so that the The pressure of the base gas in the circumferential thermal expansion chamber 55 is increased, so that the gas is heated and boosted from a higher pressure; secondly, when a small current is interrupted, the energy of the arc is not enough to make the circumferential thermal expansion chamber 5 establish enough. When the pressure is increased, the pressure cylinder 6 is required to assist in establishing the pressure. The press cylinder 6 in the present application includes two bottom surfaces 10 and an annular insulating cylinder disposed between the two bottom surfaces.

When breaking a large current, the axial airflow of the arc enters the axial thermal expansion chamber 3, and the gas is heated to increase the pressure. When the current crosses zero, the gas in the axial thermal expansion chamber 3 takes away the thermally dissociated molecules between the fractures; the interruption is small. When the current is running, the heating effect of the arc is not obvious. The gas is mainly injected into the circumferential thermal expansion 5 through the pressure cylinder 6 to increase the pressure. When the current crosses zero, the gas in the circumferential thermal expansion chamber 5 takes away the thermally free state between the fractures. molecular. To sum up, the two thermal expansion chambers have their own division of labor, so that the arc extinguishing chamber can interrupt currents of various sizes.

In a specific embodiment, the above arcing ring includes a first arcing ring 1 close to the first contact 2 and a second arcing ring 9 close to the second contact 7, and the first arcing ring 1 and the second arcing ring 9 The above-mentioned arc gap B is formed between the arcing rings 9 , and the axial thermal expansion chamber 3 communicates with the arc gap B through the moving space of the third contact 8 . Specifically, since the first contact 2, the second contact 7 and the arcing ring are all annular structures, the above-mentioned third contact 8 moves along the axial direction of the inner ring of the above-mentioned annular structure. When the third contact 8 moves When reaching between the first arc ring 1 and the second arc ring 9 , the generated arc heat gas enters the axial thermal expansion chamber 3 through the arc gap B and the space left by the third contact 8 . A specific way of connecting the axial thermal expansion chamber 3 and the arc gap B is disclosed here, which can be set according to different needs in practice, or directly communicated through a pipeline.

The axial thermal expansion chamber 3 is symmetrically arranged with respect to the center line of the third contact 8, which is the most convenient for processing and installation, and is also beneficial to the collection of axial arc energy. In practice, different arrangements can also be set according to different needs.

The axial thermal expansion chamber 3 can be made of metal material or high-strength insulating material. Because the temperature of the airflow entering the axial thermal expansion chamber 3 is very high, the first inner wall 3a, the second inner wall 3b and the third inner wall 3c of the axial thermal expansion chamber 3 are preferably covered with ablation-resistant insulating materials. Coatings may be employed to mitigate thermal damage to the materials of which they are constructed. The insulating material may be polytetrafluoroethylene.

In a further embodiment, the end of the axial thermal expansion chamber 3 in the present application away from the first contact 2 has a pressure relief port, and a pressure relief valve 4 for controlling the on-off of the pressure relief port is provided at the pressure relief port, When the pressure in the axial thermal expansion chamber 3 reaches a preset value, the pressure relief valve 4 is controlled to be turned on. Specifically, the pressure relief valve 4 does not act when the arc-extinguishing chamber is normally switched off; if other components of the arc-extinguishing chamber fail, causing the arc-extinguishing chamber to fail to extinguish the arc normally, the axial airflow generated by the arc energy will continuously enter The axial thermal expansion chamber 3 increases the air pressure limit in the axial thermal expansion chamber 3, and there is a risk of permanent mechanical damage to the arc extinguishing chamber. When the air pressure in the axial thermal expansion chamber 3 reaches the set value, the pressure relief valve 4 action to release the air pressure in the axial thermal expansion chamber 3 to avoid mechanical damage to the arc extinguishing chamber.

In order to enable the axial airflow to quickly diffuse to the edge of the axial thermal expansion chamber 3 after entering the axial thermal expansion chamber 3 , a deflector is provided on the end face of the axial thermal expansion chamber 3 disclosed in this application away from the third contact 8 , and the deflector is gradually expanded from the free end to the end connected to the axial thermal expansion chamber 3 , and the free end of the deflector faces the third contact 8 . That is, a conical protrusion is arranged in the center of the end of the axial thermal expansion chamber 3. In practice, the conical protrusion can be integrated with the pressure relief valve 4, that is, the conical protrusion is a part of the pressure relief valve 4. Realize quick installation and improve assembly efficiency.

The sum of the volumes of the circumferential thermal expansion chamber 5 and the axial thermal expansion chamber 3 disclosed in this application should be equivalent to the volume of a single thermal expansion chamber of the arc extinguishing chamber that interrupts the same current, so as to achieve the premise of the same thermal expansion chamber volume, as much as possible collected arc energy. The specific dimensions of the circumferential thermal expansion chamber 5 and the axial thermal expansion chamber 3 can be set according to actual needs, and they are all within the protection range.

In addition, the present application also discloses a switchgear, which applies the arc-extinguishing chamber disclosed in the above embodiments. Therefore, the switchgear having the arc-extinguishing chamber also has all the above-mentioned technical effects, which will not be repeated here.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other.

The above description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

An arc extinguishing chamber, comprising a first contact (2), a second contact (7), arranged between the first contact (2) and the second contact (7) and forming an arc gap The arcing ring and the third contact (8) moving in the axial direction between the first contact (2) and the second contact (7), characterized in that it further comprises:

a circumferential thermal expansion chamber (5) for collecting circumferential arc energy, the circumferential thermal expansion chamber (5) circumferentially surrounding the arc gap between the arcing rings;

An axial thermal expansion chamber (3) for collecting axial arc energy, the third contact (8) is moved from the first contact (2) to the second contact (7) during the opening movement ), the axial thermal expansion chamber (3) is arranged on the side of the first contact (2) away from the second contact (7), the axial thermal expansion chamber (3) and the The arc gap is connected.
The arc extinguishing chamber according to claim 1, further comprising: a pressure cylinder (6) for supplying high-pressure gas to the circumferential thermal expansion chamber (5), the pressure cylinder (6) being connected to the The circumferential thermal expansion chamber (5) communicates with each other.
The arc extinguishing chamber according to claim 1, characterized in that the arcing ring comprises a first arcing ring (1) close to the first contact (2) and a second contact (7) close to the first contact. ) of the second arcing ring (9), the arc gap is formed between the first arcing ring (1) and the second arcing ring (9), and the third contact (8) After moving away from the first contact (2), the axial thermal expansion chamber (3) communicates with the arc gap through the space enclosed by the first contact (2).
The arc extinguishing chamber according to claim 1, characterized in that, the axial thermal expansion chamber (3) is symmetrically arranged with respect to the center line of the third contact (8).
The arc extinguishing chamber according to claim 1, characterized in that, the axial thermal expansion chamber (3) is a metal structure, and the inner surface is covered with a high temperature resistant material.
The arc extinguishing chamber according to claim 1, characterized in that, an end of the axial thermal expansion chamber (3) away from the first contact (2) has a pressure relief port, and a pressure relief port is provided at the pressure relief port for A pressure relief valve (4) that controls the opening and closing of the pressure relief port, when the pressure in the axial thermal expansion chamber (3) reaches a preset value, the pressure relief valve (4) is controlled to be turned on.
The arc extinguishing chamber according to any one of claims 1-6, characterized in that, a deflector is provided on the end surface of the axial thermal expansion chamber (3) away from the third contact (8), and the The guide plate is gradually expanded from the free end to the end connected with the axial thermal expansion chamber, and the free end of the guide plate faces the third contact (8).
A switchgear, comprising an arc-extinguishing chamber, wherein the arc-extinguishing chamber is the arc-extinguishing chamber according to any one of claims 1-7.