Arc extinguishing chamber with flow guiding structure and circuit breaker

Abstract

The application relates to the technical field of switch equipment, in particular to an arc-extinguishing chamber with a flow guide structure and a circuit breaker. The arc-extinguishing chamber with the flow guide structure comprises a contact seat, a static support and a flow guide cylinder, the contact seat is provided with an axial flow hole, the static support is a tubular structure with an open end, is sleeved on the contact seat through the open end, the flow guide cylinder is arranged in the static support along an axial direction, the flow guide cylinder and the static support surround an annular flow guide channel, a through hole is formed in the outer wall of the static support, a gas baffle is fixedly installed on the outer wall of the static support and corresponds to the through hole, and the gas baffle is provided with a gas discharge hole. The arc-extinguishing chamber with the flow guide structure can prolong the discharge path of the hot airflow and reduce the flow speed, can effectively prevent a large amount of foreign matters such as metal particles and dust carried in the hot airflow from being discharged, avoids threatening the ground or interphase insulation at the tail of the airflow channel, and improves the insulation reliability.

Description

Technical Field

[0001] This invention relates to the field of switchgear technology, and in particular to an arc-extinguishing chamber and circuit breaker with a current-conducting structure. Background Technology

[0002] Sulfur hexafluoride (SF6) is widely used in medium-voltage, high-voltage, and ultra-high-voltage power equipment and transmission lines due to its excellent insulation properties, strong arc-extinguishing ability, and high dielectric strength. However, SF6 has a strong greenhouse effect, and its application is being limited as environmental protection requirements become more stringent. The C4F7N / CO2 / O2 mixed gas has a 98% lower global warming potential (GWP) compared to SF6, while also possessing good insulation properties, and is considered one of the most promising alternative gases to SF6.

[0003] Taking a 145kV 40kA circuit breaker as an example, the performance of C4F7N / CO2 / O2 mixed gas as the arc-extinguishing medium differs significantly from that of sulfur hexafluoride (SF6). C4F7N medium has poor recovery capability, while CO2 has a faster flow rate. Experiments show that during high-current interruption, the hot gas flow generated by the arc in a C4F7N circuit breaker often carries a large number of metal particles. The hot gas flow is discharged along the airflow channel in the arc-extinguishing chamber, and ground or phase-to-phase insulation breakdown is likely to occur at the exhaust port at the end of the airflow channel. Therefore, a reasonable design of the flow guiding structure of the arc-extinguishing chamber is required.

[0004] A Chinese utility model patent with authorization announcement number CN215377260U and authorization announcement date of December 31, 2021 discloses an arc-extinguishing chamber flow guiding structure. The arc-extinguishing chamber flow guiding structure includes a stationary support, an inner flow guiding hood, and an outer flow guiding hood. The stationary support is a cylindrical structure extending front and rear, and a radial flow passage is opened on the rear side wall of the stationary support. The inner flow guiding hood is sleeved on the outside of the stationary support, and the outer flow guiding hood is sleeved on the outside of the inner flow guiding hood. The inner flow guiding hood and the outer flow guiding hood, together with the stationary support, form a first flow guiding channel and a second flow guiding channel, respectively. This increases the length of the hot air cooling channel, changes the discharge path of the hot air, and enables the hot air to be fully cooled, and the content of metal particles in the hot air is also greatly reduced. The second flow guiding channel formed by the outer flow guiding hood and the stationary support has a rearward opening to prevent the hot air from blowing directly onto the circuit breaker housing. However, the hot airflow velocity in this flow guide structure is relatively fast, and the radial flow holes have limited blocking effect on metal particles. There is still a problem that some metal particles, dust and other foreign objects carried in the hot airflow will be discharged and cause insulation breakdown at the tail of the airflow channel. Summary of the Invention

[0005] The purpose of this invention is to provide an arc-extinguishing chamber with a flow-guiding structure to solve the problem that the existing flow-guiding structure has a high hot airflow velocity, and some metal particles, dust and other foreign objects carried in the hot airflow will be discharged and cause insulation breakdown at the tail of the airflow channel; the purpose of this invention is also to provide a circuit breaker using the arc-extinguishing chamber.

[0006] To achieve the above objectives, the arc-extinguishing chamber with a flow-guiding structure of the present invention adopts the following technical solution: An arc-extinguishing chamber with a flow-guiding structure includes a contact seat, a stationary support, and a flow-guiding cylinder. The contact seat has an axial flow hole. The stationary support is a cylindrical structure with one open end, which is sleeved on the contact seat through the open end. The flow-guiding cylinder is disposed inside the stationary support along the axial direction. The flow-guiding cylinder and the stationary support form an annular flow-guiding channel. A through hole is opened on the outer wall of the stationary support. An air baffle is fixedly installed on the outer wall of the stationary support at the corresponding opening. The air baffle has an exhaust hole.

[0007] Furthermore, the diameter of the portion of the guide tube corresponding to the annular guide channel is smaller than the diameter of the other portions.

[0008] Furthermore, exhaust holes are provided on the two side walls of the air baffle connected to the outer wall of the stationary support and on the outer wall of the air baffle at the end away from the stationary support.

[0009] Furthermore, the orientation of the exhaust port opening on the outer wall of the air baffle is the same as the diameter direction of the stationary support, and the orientation of the exhaust port opening on the side walls of the two air baffles forms an angle with both the radial direction and the axial direction of the stationary support.

[0010] Furthermore, the longitudinal section of the air deflector is a U-shaped structure, and the thickness of the sidewall of the air deflector is greater than the thickness of the outer wall of the air deflector.

[0011] Furthermore, the guide tube is fixedly installed on the contact seat and coaxial with the stationary support.

[0012] Furthermore, a guide cone is provided at one end of the stationary support away from the flow hole, with the cone tip facing the axis of the stationary support.

[0013] Beneficial Effects: The arc-extinguishing chamber with a flow-guiding structure of the present invention is an improved invention. The arc-extinguishing chamber with a flow-guiding structure of the present invention does not change the length and diameter of the arc-extinguishing chamber. A flow-guiding cylinder is installed inside the stationary support. Under the combined action of the stationary support and the flow-guiding cylinder, the exhaust path of the hot airflow is extended while reducing the flow velocity of the hot airflow, allowing the hot airflow to be fully cooled. An air baffle is installed at the opening of the stationary support to further reduce the airflow velocity. The exhaust holes on the air baffle can control the airflow direction and effectively prevent the large-scale discharge of foreign matter such as metal particles and dust carried in the hot airflow, avoiding any threat to the ground or phase-to-phase insulation of the exhaust channel tail of the stationary support, further improving insulation reliability.

[0014] The circuit breaker of the present invention adopts the following technical solution: A circuit breaker includes a housing, within which is an arc-extinguishing chamber with a flow-guiding structure. The arc-extinguishing chamber with the flow-guiding structure includes a contact seat, a stationary support, and a flow-guiding cylinder. The contact seat has an axial flow-through hole. The stationary support is a cylindrical structure with one open end, which is sleeved on the contact seat through the open end. The flow-guiding cylinder is disposed inside the stationary support along the axial direction, and the flow-guiding cylinder and the stationary support form an annular flow-guiding channel. A through hole is formed on the outer wall of the stationary support, and a baffle is fixedly installed on the outer wall of the stationary support at the corresponding opening. The baffle has an exhaust hole.

[0015] Furthermore, the diameter of the portion of the guide tube corresponding to the annular guide channel is smaller than the diameter of the other portions.

[0016] Furthermore, exhaust holes are provided on the two side walls of the air baffle connected to the outer wall of the stationary support and on the outer wall of the air baffle at the end away from the stationary support.

[0017] Furthermore, the orientation of the exhaust port opening on the outer wall of the air baffle is the same as the diameter direction of the stationary support, and the orientation of the exhaust port opening on the side walls of the two air baffles forms an angle with both the radial direction and the axial direction of the stationary support.

[0018] Furthermore, the longitudinal section of the air deflector is a U-shaped structure, and the thickness of the sidewall of the air deflector is greater than the thickness of the outer wall of the air deflector.

[0019] Furthermore, the guide tube is fixedly installed on the contact seat and coaxial with the stationary support.

[0020] Furthermore, a guide cone is provided at one end of the stationary support away from the flow hole, with the cone tip facing the axis of the stationary support.

[0021] Beneficial Effects: The circuit breaker of this invention is an improved invention. The circuit breaker of this invention has an arc-extinguishing chamber with a flow-guiding structure inside. The arc-extinguishing chamber with the flow-guiding structure does not change its length and diameter. A flow-guiding cylinder is installed inside the stationary support. Under the combined action of the stationary support and the flow-guiding cylinder, the exhaust path of the hot airflow is extended while reducing the flow velocity of the hot airflow, allowing the hot airflow to be fully cooled. A baffle is installed at the opening of the stationary support to further reduce the airflow velocity. The exhaust holes on the baffle can control the airflow direction and effectively prevent the large-scale discharge of foreign objects such as metal particles and dust carried in the hot airflow, avoiding their threat to the ground or phase-to-phase insulation at the tail of the exhaust channel of the stationary support, further improving insulation reliability. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of an embodiment of the arc-extinguishing chamber with a flow-guiding structure according to the present invention; Figure 2 The arc-extinguishing chamber with a flow-guiding structure of the present invention Figure 1 A schematic diagram of the airflow direction in the embodiment.

[0023] In the diagram: 1. Contact seat; 2. Static support; 3. Flow guide tube; 4. Flow hole; 5. Air baffle; 6. Exhaust port; 7. Flow guide cone; 8. Shielding cover; 9. Arc contact; 10. Nozzle; 11. Annular flow guide channel. Detailed Implementation

[0024] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0025] The arc-extinguishing chamber of the present invention, with a flow-guiding structure, has a flow-guiding cylinder installed inside the stationary support without changing the length and diameter of the arc-extinguishing chamber. Under the combined action of the stationary support and the flow-guiding cylinder, the flow velocity of the hot air is reduced and the exhaust path of the hot air is extended, so that the hot air is fully cooled. An air baffle is installed at the opening of the stationary support to further reduce the flow velocity of the hot air and prevent a large amount of foreign matter such as metal particles and dust carried in the hot air from being discharged, so as to avoid them threatening the ground or phase-to-phase insulation of the exhaust channel tail of the stationary support.

[0026] In a basic embodiment, such as Figure 1 As shown, a stationary support 2 is fitted onto the lower end of the contact seat 1. The stationary support 2 is fixedly installed on the contact seat 1. A guide cylinder 3 is installed inside the stationary support 2. A flow-through hole 4 is opened on the contact seat 1, communicating with the stationary support 2. A through hole is opened on the outer wall of the stationary support 2. A baffle 5 is installed on the outer wall of the stationary support 2, corresponding to the opening position of the stationary support. An exhaust hole 6 is opened on the baffle 5 to discharge the airflow. The hot airflow enters the guide cylinder 3 through the flow-through hole 4 on the contact seat 1. The hot airflow flows along the guide cylinder 3 to the tail of the stationary support 3, and flows along a U-shaped path into the annular guide channel 11 formed by the guide cylinder 3 and the stationary support 2. It is discharged into the circuit breaker through the opening of the stationary support 2 and the exhaust hole 6 of the baffle 5. Both the guide cylinder 3 and the baffle 5 are made by casting, which is low in cost and has great advantages in mass production.

[0027] In a preferred embodiment, the diameter of the end of the guide tube 3 connected to the contact seat 1 is larger than the diameter of the other end. When the hot air enters the guide tube 3 through the flow hole 4, the flow rate of the hot air remains unchanged, but the flow space becomes larger, which slows down the flow rate of the hot air.

[0028] In other embodiments, the diameter of the guide tube 3 can be uniform. The flow rate of the hot air is reduced by the static support 2 and the baffle 5. This can also cool the hot air while greatly reducing the amount of foreign matter such as metal particles and dust carried in the hot air.

[0029] In a preferred embodiment, exhaust holes 6 are provided on both side walls and the outer wall of the air baffle 5. The exhaust holes 6 on the outer wall are oriented along the diameter direction of the stationary support 2. The orientation of the exhaust holes 6 on the two side walls forms an angle with the radial and axial directions of the stationary support 2, which can discharge the airflow to different positions inside the circuit breaker housing and prevent hot airflow from directly hitting the circuit breaker housing.

[0030] In other embodiments, the position and orientation of the exhaust port 6 on the baffle 5 can be set according to the actual situation to guide the hot airflow to the area with a larger insulation margin, so as to avoid threatening the ground or phase-to-phase insulation of the exhaust channel tail of the static support 2.

[0031] In a preferred embodiment, the thickness of the two side walls of the air baffle 5 is greater than the thickness of the outer wall of the air baffle, so as to prevent metal particles, dust and other foreign objects from causing insulation breakdown at the tail of the airflow channel.

[0032] In other embodiments, the thickness of the outer wall of the air deflector can be the same as the thickness of the side wall of the air deflector. Both are relatively thick, which can prevent foreign objects such as metal particles and dust from causing insulation breakdown at the tail of the airflow channel.

[0033] In a preferred embodiment, the guide tube 3 is fixedly installed on the contact seat 1 to facilitate the installation of the guide tube 3. The guide tube 3 is coaxial with the stationary support 2, so that the annular guide channel formed by the guide tube 3 and the stationary support 2 is evenly distributed. The hot airflow is evenly distributed in the annular guide channel, which can make the hot airflow cool more evenly and fully.

[0034] In other embodiments, the guide tube 3 and the stationary support 2 may not be coaxially arranged, which does not affect their effect of extending the cooling path of the hot airflow, so that the hot airflow can be fully cooled before being discharged.

[0035] In a preferred embodiment, a guide cone 7 is provided at the tail of the stationary support 2. When the hot airflow flows to the tail of the stationary support 2 under the guidance of the guide tube 3, the hot airflow is divided into two parts by the guide cone 7 and flows into the annular guide channel 11 along a U-shaped path. Finally, it is discharged from the exhaust hole 6 on the baffle 5. The guide cone 7 can make the hot airflow flow more smoothly when it flows into the annular guide channel 11.

[0036] In other embodiments, the guide cone 7 may not be provided inside the static support 2, and the direction of the hot airflow will not be affected. The hot airflow can still be sufficiently cooled and slowed down before being discharged.

[0037] The specific embodiment of the arc-extinguishing chamber with a flow-guiding structure of the present invention is as follows: like Figure 2As shown, when the moving and stationary arc contacts of the circuit breaker separate, the hot air generated by the arc enters the contact seat 1 through the nozzle 10. The contact seat 1 is equipped with an arc contact 9. The hot air flows rapidly through the flow passage 4 to the guide tube 3. When the hot air enters the guide tube 3, the flow velocity decreases. Under the guidance of the guide tube 3, it flows to the tail of the stationary support 2. Under the action of the guide cone 7, it changes direction and flows into the annular guide channel 11 formed by the stationary support 2 and the guide tube 3, and meanders to the opening of the stationary support 2. Finally, it is discharged into the circuit breaker through the exhaust hole 6 on the air baffle 5. When the hot airflow flows along the guide tube 3 to the tail of the stationary support 2, the hot airflow is blocked by the combined action of the stationary support 2 and the guide cone 7, and the flow velocity is greatly reduced. At this time, some metal particles, dust and other foreign objects carried in the hot airflow will fall into the stationary support 2. When the hot airflow flows to the opening of the stationary support 2 and is discharged outward, it will be blocked by the baffle 5, and its flow velocity will be further reduced. Most of the metal particles carried in the hot airflow will fall into the stationary support 2. At the same time, by reasonably setting the position and orientation of the exhaust hole 6 on the baffle 5, the hot airflow can be guided to the area with a large insulation margin inside the circuit breaker housing, so as not to threaten the ground or phase-to-phase insulation of the tail of the exhaust channel of the stationary support.

[0038] The specific implementation of the circuit breaker of the present invention is as follows: The circuit breaker of the present invention includes a housing, and the arc-extinguishing chamber described above is provided inside the housing. The specific implementation of the arc-extinguishing chamber with a flow-guiding structure is as described above and will not be repeated here.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. An arc-extinguishing chamber with a flow-guiding structure, comprising a contact seat, a stationary support, and a flow-guiding cylinder, wherein the contact seat has an axial flow hole, and the stationary support is a cylindrical structure open at one end, and is sleeved on the contact seat through the open end, characterized in that, The flow guide tube is arranged inside the stationary support along the axial direction, and the flow guide tube and the stationary support form an annular flow guide channel. A through hole is opened on the outer wall of the stationary support, and an air baffle is fixedly installed on the outer wall of the stationary support at the corresponding opening. The air baffle has an exhaust hole.

2. The arc-extinguishing chamber with a flow-guiding structure according to claim 1, characterized in that, The diameter of the portion of the guide tube corresponding to the annular guide channel is smaller than the diameter of the other portions.

3. The arc-extinguishing chamber with a flow-guiding structure according to claim 1, characterized in that, Exhaust holes are provided on the two side walls of the air baffle connected to the outer wall of the stationary support and on the outer wall of the air baffle away from the stationary support.

4. The arc-extinguishing chamber with a flow-guiding structure according to claim 3, characterized in that, The orientation of the exhaust port opening on the outer wall of the air baffle is the same as the diameter direction of the stationary support, and the orientation of the exhaust port opening on the side walls of the two air baffles forms an angle with both the radial direction and the axial direction of the stationary support.

5. The arc-extinguishing chamber with a flow-guiding structure according to any one of claims 1-4, characterized in that, The longitudinal section of the air deflector is U-shaped, and the thickness of the sidewall of the air deflector is greater than the thickness of the outer wall of the air deflector.

6. The arc-extinguishing chamber with a flow-guiding structure according to any one of claims 1-4, characterized in that, The guide tube is fixedly installed on the contact seat and is coaxial with the stationary support.

7. The arc-extinguishing chamber with a flow-guiding structure according to any one of claims 1-4, characterized in that, A guide cone is provided at one end of the stationary support away from the flow hole, with the cone tip facing the axis of the stationary support.

8. A circuit breaker, comprising a housing, wherein an arc-extinguishing chamber with a flow-guiding structure is provided within the housing, the arc-extinguishing chamber with the flow-guiding structure comprising a contact seat, a stationary support, and a flow-guiding cylinder, wherein the contact seat has an axial flow-through hole, and the stationary support is a cylindrical structure open at one end and is sleeved onto the contact seat through the open end, characterized in that, The flow guide tube is arranged inside the stationary support along the axial direction, and the flow guide tube and the stationary support form an annular flow guide channel. A through hole is opened on the outer wall of the stationary support, and an air baffle is fixedly installed on the outer wall of the stationary support at the corresponding opening. The air baffle has an exhaust hole.

9. The circuit breaker according to claim 8, characterized in that, The diameter of the portion of the guide tube corresponding to the annular guide channel is smaller than the diameter of the other portions.

10. The circuit breaker according to claim 8, characterized in that, Exhaust holes are provided on the two side walls of the air baffle connected to the outer wall of the stationary support and on the outer wall of the air baffle away from the stationary support.

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