A low voltage DC circuit breaker arc extinguishing system

Abstract

The present invention provides an arc extinguishing system for a low-voltage DC circuit breaker, belonging to the field of arc extinguishing of low-voltage DC circuit breakers. The system comprises a shell and an operating handle arranged in the shell. An arc extinguishing chamber is arranged in the shell, and further comprises: a trigger gas injection mechanism: the trigger gas injection mechanism is arranged in the arc extinguishing chamber; an arc extinguishing mechanism, the arc extinguishing mechanism is arranged in the arc extinguishing chamber; and a fire extinguishing mechanism, the fire extinguishing mechanism is arranged in the arc extinguishing chamber. The present invention provides a trigger gas injection mechanism linked to the operating handle. When the low-voltage circuit breaker is powered off, the operating handle trips, and nitrogen forms a high-speed airflow through the injection channel, which greatly increases the airflow speed. The airflow direction forms a 45-degree angle with the direction in which the arc is interrupted by the arc extinguishing plate, so that the airflow can blow the arc surface more effectively, increase the contact area between the arc and the surrounding medium, and contribute to the cooling of the arc. At the same time, the airflow cooperates with the arc extinguishing mechanism to interrupt and extinguish the arc, thereby improving the arc extinguishing effect.

Description

Technical Field

[0001] The present invention relates to the field of arc extinguishing of low-voltage DC circuit breakers, and in particular to an arc extinguishing system of a low-voltage DC circuit breaker. Background Art

[0002] Low-voltage circuit breakers, also known as automatic air switches, are primarily used in AC and DC low-voltage power grids. They can be opened and closed manually or electrically, and can protect circuits and electrical equipment from overload, short circuit, and undervoltage. They can also be used for infrequent motor starting. They are important control and protection devices. Low-voltage circuit breakers are switching devices that can connect and disconnect not only normal load current and overload current, but also short-circuit current. In addition to their control function, low-voltage circuit breakers also have certain protective functions, such as overload, short circuit, undervoltage, and leakage protection.

[0003] Low-voltage circuit breakers are usually equipped with arc extinguishing devices to extinguish arcs generated by contacts in electrical equipment to ensure safe operation. Current arc extinguishing devices mostly use multiple groups of arc extinguishing plates to eliminate arcs generated during disconnection. When a large current is interrupted between the moving and static contacts and an arc is generated, the arc is pulled into the arc extinguishing plates by the contraction force of the magnetic lines of force, dividing a long arc into multiple short arcs, which plays a role in arc cooling and also cools and deionizes the arc extinguishing gas, thereby achieving the arc extinguishing effect. Studies have shown that during the arc extinguishing process, the more arc extinguishing plates used in the arc extinguishing chamber to cut the arc, the higher the voltage drop on the arc, the arc cannot maintain combustion and is extinguished quickly, and the better the breaking capacity.

[0004] Most of the current arc extinguishing devices of low-voltage circuit breakers improve the effect of breaking the arc by adding arc extinguishing plates. However, the space in the arc extinguishing chamber is limited. Adding multiple sets of arc extinguishing plates will occupy more space, resulting in obstruction of the air flow channel, affecting the cooling effect of the arc, and making it impossible for the arc to be effectively cooled, which will cause the arc extinguishing plates to burn or reignite. In severe cases, it will cause a short circuit or fire inside the circuit breaker, affecting the arc extinguishing effect. Secondly, it is difficult to quickly extinguish the fire in the arc extinguishing chamber of the current low-voltage circuit breaker, which will affect the surrounding electrical equipment and cause the power system to be paralyzed. How to invent a low-voltage DC circuit breaker arc extinguishing system to improve these problems has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] In order to remedy the above shortcomings, the present invention provides an arc extinguishing system for a low-voltage DC circuit breaker, which aims to improve the arc-breaking effect of most current arc extinguishing devices of low-voltage circuit breakers by adding arc extinguishing plates. However, the space in the arc extinguishing chamber is limited. Adding multiple sets of arc extinguishing plates will occupy more space, resulting in obstruction of the airflow channel, affecting the cooling effect of the arc, and making it impossible for the arc to be effectively cooled.

[0006] The present invention is achieved in that:

[0007] The present invention provides an arc extinguishing system for a low-voltage DC circuit breaker, comprising a shell and an operating handle arranged in the shell, wherein an electromagnetic solenoid is arranged in the shell, a contact is provided at one end of the electromagnetic solenoid, a main contact is provided in the shell, a line solenoid mechanical structure is provided in the shell, an adjustment screw is provided in the shell, a bimetallic strip is provided at one end of the adjustment screw, an outlet terminal is provided at one end of the bimetallic strip, the other end of the electromagnetic solenoid contacts the line solenoid mechanical structure, the line solenoid mechanical structure contacts the main contact, the main contact contacts the bimetallic strip, a ventilation opening is provided on an outer wall of the shell, an arc extinguishing chamber is provided in the shell, and the system further comprises: a trigger gas injection mechanism: the trigger gas injection mechanism is arranged in the arc extinguishing chamber; an arc extinguishing mechanism: the arc extinguishing mechanism is arranged in the arc extinguishing chamber; and a fire extinguishing mechanism: the fire extinguishing mechanism is arranged in the arc extinguishing chamber.

[0008] Preferably, the trigger gas injection mechanism includes an injection seat provided on the inner wall of the arc extinguishing chamber, six groups of injection channels are opened inside the injection seat, six groups of air intake covers connected to the injection channels are provided on the side wall of the injection seat, and one end of the six groups of air intake covers is provided with a connecting pipe, the outer wall of the shell is provided with a fixed pipe, one end of the connecting pipe is connected to the interior of the fixed pipe, the outer wall of the fixed pipe is provided with a gas supply pipe, the outer wall of the shell is provided with an air pressure chamber, one end of the air supply pipe is connected to the air pressure chamber, a one-way solenoid valve is provided inside the air supply pipe, a piston head is provided slidingly in the air pressure chamber, and a piston is provided on the side wall of the piston head Rod, the outer wall of the shell is provided with a sleeve, and a movable plate is slidably connected in the sleeve, one end of the piston rod passes through the side wall of the sleeve and is connected to the side wall of the movable plate, and the other side wall of the movable plate is provided with a movable rod, and the outer wall of the movable rod is sleeved with a storage spring, one end of the storage spring is connected to the inner wall of the sleeve, and the other end of the storage spring is connected to the side wall of the movable plate, the side wall of the shell is provided with a guide rail, and a guide block is slidably connected in the guide rail, one end of the movable rod passes through the inner wall of the sleeve and is connected to the side wall of the guide block, the guide block side wall is hinged with a connecting rod, and one end of the connecting rod is hinged to the side wall of the operating handle.

[0009] Preferably, the arc extinguishing mechanism includes multiple groups of first arc extinguishing plates, second arc extinguishing plates and third arc extinguishing plates arranged horizontally on the inner wall of the arc extinguishing chamber, and splicing plates are provided on the tops of the multiple groups of first arc extinguishing plates, second arc extinguishing plates and third arc extinguishing plates. A first insulating plate is installed through the multiple groups of the first arc extinguishing plates, a second insulating plate is installed through the multiple groups of the second arc extinguishing plates, and a third insulating plate is installed through the multiple groups of the third arc extinguishing plates. Six groups of heat dissipation fins are provided on the inner wall of the arc extinguishing chamber.

[0010] Preferably, the six groups of heat dissipating fins are arranged between the first arc-extinguishing fin, the second arc-extinguishing fin and the third arc-extinguishing fin, and are in contact with the side walls of the first arc-extinguishing fin, the second arc-extinguishing fin and the third arc-extinguishing fin.

[0011] Preferably, the heights of the first arc-extinguishing plates, the second arc-extinguishing plates and the third arc-extinguishing plates are arranged in sequence from low to high, and the arrangement spacing between multiple groups of first arc-extinguishing plates, second arc-extinguishing plates and third arc-extinguishing plates is reduced in sequence.

[0012] Preferably, the injection channel is arranged in a Venturi shape, and the injection channel is arranged at an angle of 45 degrees to the first arc-extinguishing piece.

[0013] Preferably, the inner wall of the arc extinguishing chamber is provided with a plurality of groups of guide plates, the plurality of groups of guide plates are distributed in a linear array on the inner wall of the arc extinguishing chamber, and the guide plates are arranged in an arc shape.

[0014] Preferably, outer walls of the first arc-extinguishing plate, the second arc-extinguishing plate and the third arc-extinguishing plate are all provided with a metal oxide composite coating.

[0015] Preferably, the fire extinguishing mechanism includes an ultraviolet flame sensor provided on the inner wall of the arc extinguishing chamber, a fire extinguishing tank provided on the inner wall of the arc extinguishing chamber, a delivery pipe provided at one end of the fire extinguishing tank, a spray plate provided on the inner wall of the arc extinguishing chamber, and multiple groups of nozzles provided on the side wall of the spray plate.

[0016] Preferably, the spray plate is arranged in an inclined shape in the arc extinguishing chamber, and multiple groups of spray heads are distributed in a linear array on the side wall of the spray plate, and the spray heads are made of aluminum alloy material.

[0017] The beneficial effects of the present invention are:

[0018] 1. The present invention provides a trigger gas injection mechanism linked to the operating handle. When the low-voltage circuit breaker is de-energized and the operating handle trips (relative to when the main contacts are separated), the force storage spring is released, so that the piston head can move quickly and squeeze the nitrogen in the pressure chamber. The nitrogen forms a high-speed airflow through the injection channel, and the airflow speed is greatly increased. The airflow direction forms a 45-degree angle with the direction in which the arc is interrupted by the arc extinguishing plate, so that the airflow can blow the arc surface more effectively, increase the contact area between the arc and the surrounding medium, help cool the arc, and promote the elongation and diffusion of the arc. The elongated arc increases the arc length, increases the arc voltage, and reduces the conductivity of the arc gap, which is conducive to the extinction of the arc. At the same time, the arc extinguishing mechanism is used to interrupt and extinguish the arc, which can improve the arc extinguishing effect. Therefore, the combination of the trigger gas injection mechanism and the arc extinguishing mechanism can ensure the internal space of the arc extinguishing chamber, and there is no need to increase the arc extinguishing effect by adding arc extinguishing plates. The airflow channel between the arc extinguishing plates is ensured to be smooth, further improving the arc extinguishing effect.

[0019] 2. The present invention provides heat dissipation fins, which can be used in conjunction with high-speed airflow to carry the heat of the arc-extinguishing plate out of the vents, thereby reducing the temperature of the arc-extinguishing plate and preventing the arc from reigniting. This can avoid heat accumulation in the arc-extinguishing chamber, reduce the risk of arc-extinguishing plate ablation or reignition, and improve safety.

[0020] 3. The present invention provides a fire extinguishing mechanism. The ultraviolet flame sensor can detect the reignition of the arc or open flame. When a fire is detected in the arc extinguishing chamber, the fire can be extinguished quickly to prevent the fire from growing larger and affecting surrounding electrical equipment, causing power system paralysis, and further improving the safety of low-voltage DC circuit breaker roommates. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 This is a schematic diagram of the overall structure of a low-voltage DC circuit breaker arc extinguishing system provided by an embodiment of the present invention;

[0023] Figure 2 This is a rear view of the arc extinguishing system structure of a low-voltage DC circuit breaker provided by an embodiment of the present invention;

[0024] Figure 3 This is a schematic structural diagram of a trigger gas injection mechanism of an arc extinguishing system of a low-voltage DC circuit breaker provided by an embodiment of the present invention;

[0025] Figure 4 This is a schematic structural diagram of an ejection channel and an air intake cover of an arc extinguishing system of a low-voltage DC circuit breaker provided by an embodiment of the present invention;

[0026] Figure 5 This is a schematic structural diagram of an arc extinguishing mechanism of an arc extinguishing system of a low-voltage DC circuit breaker provided by an embodiment of the present invention;

[0027] Figure 6 This is a side view of the arc extinguishing mechanism structure of an arc extinguishing system of a low-voltage DC circuit breaker provided by an embodiment of the present invention;

[0028] Figure 7 This is a schematic diagram of the heat dissipation fin structure of a low-voltage DC circuit breaker arc extinguishing system provided by an embodiment of the present invention;

[0029] Figure 8 Schematic diagram of arc extinguishing plates and metal oxide composite coatings in an arc extinguishing system structure of a low-voltage DC circuit breaker provided by an embodiment of the present invention;

[0030] Figure 9 This is a low voltage DC circuit breaker arc extinguishing system provided by the embodiment of the present invention Figure 1 A magnified view of the structure at center A.

[0031] In the figure: 1. housing; 2. operating handle; 3. electromagnetic solenoid; 4. contact; 5. arc extinguishing chamber; 6. trigger gas injection mechanism; 600. connecting rod; 601. guide rail; 602. guide block; 603. movable rod; 604. sleeve; 605. storage spring; 606. movable plate; 607. piston rod; 608. piston head; 609. air pressure chamber; 610. one-way electromagnetic valve; 611. gas pipe; 612. fixed pipe; 613. injection seat; 614. injection channel; 615. air inlet cover; 616. connecting pipe; 7. arc extinguishing mechanism; 70 0. First arc-extinguishing plate; 701. First insulating plate; 702. Second arc-extinguishing plate; 703. Second insulating plate; 704. Third arc-extinguishing plate; 705. Third insulating plate; 706. Splicing plate; 707. Heat dissipation fins; 8. Fire extinguishing mechanism; 800. Fire extinguisher tank; 801. Delivery pipe; 802. Spray plate; 803. Spray nozzle; 804. Ultraviolet flame sensor; 9. Vent; 10. Guide plate; 11. Main contact; 12. Adjustment screw; 13. Bimetallic strip; 14. Outlet terminal; 15. Wire coil mechanical structure; 16. Metal oxide composite coating. DETAILED DESCRIPTION

[0032] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0033] Example, refer to Figures 1-9A low-voltage DC circuit breaker arc extinguishing system includes a housing 1 and an operating handle 2 arranged in the housing 1, an electromagnetic solenoid 3 is provided in the housing 1, a contact 4 is provided at one end of the electromagnetic solenoid 3, a main contact 11 is provided in the housing 1, a wire solenoid mechanical structure 15 is provided in the housing 1, an adjusting screw 12 is provided in the housing 1, a bimetallic strip 13 is provided at one end of the adjusting screw 12, an outlet terminal 14 is provided at one end of the bimetallic strip 13, the other end of the electromagnetic solenoid 3 is in contact with the wire solenoid mechanical structure 15, the wire solenoid mechanical structure 15 is in contact with the main contact 11, and the main contact 11 is in contact with the wire solenoid mechanical structure 15. The bimetallic strips 13 are in contact with each other, a ventilation hole 9 is provided on the outer wall of the shell 1, an arc extinguishing chamber 5 is provided in the shell 1, and a plurality of guide plates 10 are provided on the inner wall of the arc extinguishing chamber 5. The plurality of guide plates 10 are distributed in a linear array on the inner wall of the arc extinguishing chamber 5, and the guide plates 10 are arranged in an arc shape. With the cooperation of the guide plates 10, the arc can be guided into the arc extinguishing chamber 5 for arc extinguishing. It also includes: a triggering gas injection mechanism 6: the triggering gas injection mechanism 6 is arranged in the arc extinguishing chamber 5; an arc extinguishing mechanism 7, the arc extinguishing mechanism 7 is arranged in the arc extinguishing chamber 5; a fire extinguishing mechanism 8, the fire extinguishing mechanism 8 is arranged in the arc extinguishing chamber 5.

[0034] The trigger gas injection mechanism 6 includes an injection seat 613 provided on the inner wall of the arc extinguishing chamber 5, six groups of injection channels 614 are opened inside the injection seat 613, six groups of air intake covers 615 connected to the injection channels 614 are provided on the side wall of the injection seat 613, and one end of each of the six air intake covers 615 is provided with a connecting pipe 616. A fixed pipe 612 is provided on the outer wall of the shell 1, and one end of the connecting pipe 616 is connected to the interior of the fixed pipe 612. A gas supply pipe 611 is provided on the outer wall of the fixed pipe 612. An air pressure chamber 609 is provided on the outer wall of the shell 1, and one end of the air supply pipe 611 is connected to the air pressure chamber 609. A one-way solenoid valve 610 is provided inside the air supply pipe 611. A piston head 608 is provided to slide in the air pressure chamber 609, and a piston rod 607 is provided on the side wall of the piston head 608. A sleeve 604 is provided on the outer wall of the body 1, and a movable plate 606 is provided in a sliding connection inside the sleeve 604. One end of the piston rod 607 passes through the side wall of the sleeve 604 and is connected to the side wall of the movable plate 606. A movable rod 603 is provided on the other side wall of the movable plate 606. A storage spring 605 is sleeved on the outer wall of the movable rod 603. One end of the storage spring 605 is connected to the inner wall of the sleeve 604, and the other end of the storage spring 605 is connected to the side wall of the movable plate 606. A guide rail 601 is provided on the side wall of the shell 1, and a guide block 602 is provided in a sliding connection inside the guide rail 601. One end of the movable rod 603 passes through the inner wall of the sleeve 604 and is connected to the side wall of the guide block 602. The side wall of the guide block 602 is hinged with a connecting rod 600, and one end of the connecting rod 600 is hinged to the side wall of the operating handle 2.

[0035] It should be noted that: when the low-voltage circuit breaker is de-energized, the operating handle 2 trips (relative to when the main contact 11 is separated), the force storage spring 605 is released, so that the piston head 608 can move quickly and squeeze the nitrogen in the air pressure chamber 609. The nitrogen forms a high-speed airflow through the injection channel 614, and the airflow speed will be greatly increased. The airflow direction is at a 45-degree angle to the direction in which the arc extinguishing plate breaks the arc, so that the airflow can blow the arc surface more effectively, increase the contact area between the arc and the surrounding medium, help cool the arc, and promote the elongation and diffusion of the arc. The elongated arc increases the arc length, which increases the arc voltage and reduces the conductivity of the arc gap, which is conducive to the extinction of the arc.

[0036] The arc extinguishing mechanism 7 includes a plurality of first arc extinguishing pieces 700, a second arc extinguishing piece 702 and a third arc extinguishing piece 704 arranged transversely on the inner wall of the arc extinguishing chamber 5, a plurality of first arc extinguishing pieces 700, a second arc extinguishing piece 702 and a third arc extinguishing piece 704 are provided with a splicing plate 706 on the top of each of the plurality of first arc extinguishing pieces 700, a first insulating plate 701 is installed through the plurality of first arc extinguishing pieces 700, a second insulating plate 703 is installed through the plurality of second arc extinguishing pieces 702, a third insulating plate 705 is installed through the plurality of third arc extinguishing pieces 704, and the arc extinguishing chamber 5 Six groups of heat dissipation fins 707 are provided on the inner wall, and the six groups of heat dissipation fins 707 are arranged between the first arc-extinguishing plate 700, the second arc-extinguishing plate 702 and the third arc-extinguishing plate 704, and are in contact with the side walls of the first arc-extinguishing plate 700, the second arc-extinguishing plate 702 and the third arc-extinguishing plate 704. The heights of the first arc-extinguishing plate 700, the second arc-extinguishing plate 702 and the third arc-extinguishing plate 704 are arranged in sequence from low to high, and the arrangement spacing between multiple groups of first arc-extinguishing plates 700, second arc-extinguishing plates 702 and third arc-extinguishing plates 704 is reduced in sequence.

[0037] It should be noted that the arc extinguishing plates are arranged in order from low to high, so that the arc will be gradually elongated and dispersed when passing through the arc extinguishing plates. The elongation of the arc increases the arc length, which increases the arc voltage and reduces the conductivity of the arc gap, which is conducive to the extinction of the arc. At the same time, when the arc passes through arc extinguishing plates of different heights, it will be divided into shorter arc segments many times. These short arc segments are easier to extinguish, and the arrangement spacing between multiple groups of arc extinguishing plates is reduced in sequence, which further enhances the dispersion and elongation effect of the arc and improves the arc extinguishing efficiency. At the same time, the flow path between the arc extinguishing plates will also change and bend to increase the arc's residence time in the arc extinguishing plates. Time increases the contact time between the arc and the arc extinguishing plate. A longer contact time means that the arc has more opportunities to exchange heat with the arc extinguishing plate. The heat of the arc can be absorbed and dispersed by the arc extinguishing plate more quickly, which helps to reduce the arc temperature, promote the extinction of the arc, and improve the arc extinguishing effect. The arc extinguishing plate absorbs the heat of the arc when extinguishing the arc, and can dissipate the heat under the action of the heat dissipation fins 707, thereby cooperating with the high-speed airflow to carry the heat out from the vent 9, reducing the temperature of the arc extinguishing plate, preventing the arc from reigniting, and avoiding heat accumulation in the arc extinguishing chamber 5, reducing the risk of arc erosion or reignition of the arc extinguishing plate, and improving safety.

[0038] The injection channel 614 is arranged in a Venturi shape, and the injection channel 614 and the first arc-extinguishing piece 700 are arranged at an angle of 45 degrees.

[0039] It should be noted that: the injection channel 614 adopts a gradually converging and expanding Venturi structure, and the air flow velocity will be greatly improved; when the air flow blows the arc at a 45-degree angle, the air flow can blow the arc surface more effectively, increase the contact area between the arc and the surrounding medium, help cool the arc, and promote the elongation and diffusion of the arc. The elongated arc increases the arc length, which increases the arc voltage and reduces the conductivity of the arc gap, which is conducive to the extinction of the arc.

[0040] The outer walls of the first arc-extinguishing piece 700 , the second arc-extinguishing piece 702 and the third arc-extinguishing piece 704 are all provided with a metal oxide composite coating 16 .

[0041] It should be noted that the metal oxide composite coating 16 has excellent thermal conductivity and electrical insulation properties. During the arc extinguishing process, when an arc is generated, the coating can quickly absorb and disperse the heat generated by the arc, reducing the arc temperature and thus accelerating the arc extinction. The arc combustion process generates high temperatures and strong electrical corrosion, causing serious damage to the arc extinguishing plate surface. The metal oxide composite coating 16 has excellent high temperature and corrosion resistance, effectively resisting arc erosion and extending the service life of the arc extinguishing plate.

[0042] The fire extinguishing mechanism 8 includes an ultraviolet flame sensor 804 provided on the inner wall of the arc extinguishing chamber 5, a fire extinguishing tank 800 provided on the inner wall of the arc extinguishing chamber 5, a delivery pipe 801 provided at one end of the fire extinguishing tank 800, a spray plate 802 provided on the inner wall of the arc extinguishing chamber 5, and multiple groups of nozzles 803 provided on the side wall of the spray plate 802. The spray plate 802 is arranged in an inclined shape in the arc extinguishing chamber 5, and the multiple groups of nozzles 803 are distributed in a linear array on the side wall of the spray plate 802, and the nozzles 803 are made of aluminum alloy material.

[0043] It should be noted that the ultraviolet flame sensor 804 is electrically connected to the external controller CPU. When the ultraviolet flame sensor 804 detects an open flame of an arc reignited fire, it will quickly send a signal to the CPU. The CPU will process the signal and convey the instruction to the corresponding actuator (the actuator is the fire extinguishing tank 800). The fire extinguishing agent in the fire extinguishing tank 800 is quickly transported from the delivery pipe 801 to the spray plate 802, and then sprayed out through the nozzle 803, which can quickly extinguish the fire.

[0044] The working principle of the arc extinguishing system of a low-voltage DC circuit breaker: When a load, short circuit or leakage occurs during the use of the low-voltage DC circuit breaker, the operating handle 2 will trip quickly to cut off the power. At this time, an arc will appear. With the cooperation of the guide plate 10, the arc can be guided to the first arc extinguishing plate 700, the second arc extinguishing plate 702 and the third arc extinguishing plate 704. When the operating handle 2 trips (when it does not trip, the storage spring 605 is in a squeezed state), it will drive the connecting rod 600 to rotate, and the connecting rod 600 will drive the guide block 602 to move on the guide rail 601. Under the action of the elastic force of the storage spring 605, the movable plate 606 will be quickly driven to move. At the same time, the movable plate 606 drives the piston rod 607 and the piston When the piston head 608 moves, the piston head 608 can squeeze the nitrogen in the air pressure chamber 609. The nitrogen enters the gas pipe 611 through the one-way solenoid valve 610, and then enters the injection channel 614 through the fixed pipe 612 and the air inlet cover 615. The nitrogen forms a high-speed airflow through the injection channel 614 (the injection channel 614 adopts a gradually converging and gradually expanding Venturi structure, which greatly increases the airflow speed). The airflow direction forms a 45-degree angle with the direction in which the arc is interrupted by the arc extinguishing plate, which can accelerate the cooling of the arc. The arc then passes through the first arc extinguishing plate 700, the second arc extinguishing plate 702, and the third arc extinguishing plate 704, which have gradually decreasing spacing, thereby gradually interrupting the arc and finally extinguishing it, thereby improving the arc extinguishing effect.

[0045] When the cooled arc passes between the first arc-extinguishing plate 700, the second arc-extinguishing plate 702, and the third arc-extinguishing plate 704, the high-speed airflow carries the heat emitted by the heat dissipation fins 707 out of the vents 9, thereby lowering the temperature of the arc-extinguishing plates, preventing the arc from reigniting, and reducing the risk of arc erosion or reignition.

[0046] Under the action of the ultraviolet flame sensor 804, the reignition of the arc or open flame can be detected. The fire extinguisher in the fire extinguisher tank 800 is quickly transported from the delivery pipe 801 to the spray plate 802, and then sprayed out through the nozzle 803, which can quickly extinguish the fire and prevent the fire from growing larger and affecting surrounding electrical equipment.

[0047] It should be noted that the specific model and specifications of the ultraviolet flame sensor need to be selected and determined based on the actual specifications of the device. The specific selection calculation method adopts the existing technology in this field, so it will not be described in detail.

[0048] The above is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A low-voltage DC circuit breaker arc extinguishing system, comprising a housing (1) and an operating handle (2) arranged in the housing (1), an electromagnetic solenoid (3) is arranged in the housing (1), one end of the electromagnetic solenoid (3) is provided with a contact (4), a main contact (11) is arranged in the housing (1), a wire solenoid mechanical structure (15) is arranged in the housing (1), an adjusting screw (12) is arranged in the housing (1), one end of the adjusting screw (12) is provided with a bimetallic strip (13), one end of the bimetallic strip (13) is provided with an outlet terminal (14), the other end of the electromagnetic solenoid (3) is in contact with the wire solenoid mechanical structure (15), the wire solenoid mechanical structure (15) is in contact with the main contact (11), the main contact (11) is in contact with the bimetallic strip (13), an outer wall of the housing (1) is provided with a vent (9), an arc extinguishing chamber (5) is arranged in the housing (1), and the system is characterized in that: Also includes: Trigger gas injection mechanism (6): the trigger gas injection mechanism (6) is arranged in the arc extinguishing chamber (5); An arc extinguishing mechanism (7), the arc extinguishing mechanism (7) being arranged in the arc extinguishing chamber (5); A fire extinguishing mechanism (8), the fire extinguishing mechanism (8) being arranged in the arc extinguishing chamber (5); The trigger gas injection mechanism (6) includes an injection seat (613) provided on the inner wall of the arc extinguishing chamber (5), six groups of injection channels (614) are opened inside the injection seat (613), six groups of air inlet covers (615) connected to the injection channels (614) are provided on the side wall of the injection seat (613), and one end of each of the six groups of air inlet covers (615) is provided with a connecting pipe (616), and the outer wall of the shell (1) is provided with a fixing pipe (612), one end of the connecting pipe (616) is provided with a fixing pipe (612). The fixed tube (612) is connected to the inside of the fixed tube (612), the outer wall of the fixed tube (612) is provided with an air supply pipe (611), the outer wall of the shell (1) is provided with an air pressure chamber (609), one end of the air supply pipe (611) is connected to the air pressure chamber (609), a one-way electromagnetic valve (610) is provided inside the air supply pipe (611), a piston head (608) is provided in a sliding manner in the air pressure chamber (609), and a piston rod (607) is provided on the side wall of the piston head (608). The outer wall of the housing (1) is provided with a sleeve (604), and a movable plate (606) is slidably connected inside the sleeve (604). One end of the piston rod (607) passes through the side wall of the sleeve (604) and is connected to the side wall of the movable plate (606). The other side wall of the movable plate (606) is provided with a movable rod (603). The outer wall of the movable rod (603) is sleeved with a storage spring (605), and one end of the storage spring (605) is connected to the inner wall of the sleeve (604). The other end of the force storage spring (605) is connected to the side wall of the movable plate (606), the side wall of the housing (1) is provided with a guide rail (601), and a guide block (602) is provided in a sliding connection inside the guide rail (601), one end of the movable rod (603) passes through the inner side wall of the sleeve (604) and is connected to the side wall of the guide block (602), and the side wall of the guide block (602) is hingedly provided with a connecting rod (600), and one end of the connecting rod (600) is hingedly connected to the side wall of the operating handle (2); The arc extinguishing mechanism (7) comprises an arc extinguishing chamber (5) whose inner wall is laterally provided with a plurality of groups of first arc extinguishing plates (700), second arc extinguishing plates (702) and third arc extinguishing plates (704), and six groups of heat dissipation fins (707) are provided on the inner wall of the arc extinguishing chamber (5).

2. The arc extinguishing system of a low voltage DC circuit breaker according to claim 1, characterized in that: A splicing plate (706) is provided on the top of each of the multiple groups of first arc-extinguishing plates (700), second arc-extinguishing plates (702) and third arc-extinguishing plates (704); a first insulating plate (701) is installed through the multiple groups of the first arc-extinguishing plates (700); a second insulating plate (703) is installed through the multiple groups of the second arc-extinguishing plates (702); and a third insulating plate (705) is installed through the multiple groups of the third arc-extinguishing plates (704).

3. The arc extinguishing system of a low voltage DC circuit breaker according to claim 1, characterized in that: The six groups of heat dissipation fins (707) are arranged between the first arc-extinguishing plate (700), the second arc-extinguishing plate (702) and the third arc-extinguishing plate (704), and are in contact with the side walls of the first arc-extinguishing plate (700), the second arc-extinguishing plate (702) and the third arc-extinguishing plate (704).

4. The arc extinguishing system for a low voltage DC circuit breaker according to claim 1, characterized in that: The heights of the first arc-extinguishing plates (700), the second arc-extinguishing plates (702) and the third arc-extinguishing plates (704) are arranged in sequence from low to high, and the arrangement spacing between the multiple groups of first arc-extinguishing plates (700), second arc-extinguishing plates (702) and third arc-extinguishing plates (704) is reduced in sequence.

5. The arc extinguishing system for a low voltage DC circuit breaker according to claim 1, characterized in that: The injection channel (614) is arranged in a Venturi shape, and the injection channel (614) and the first arc-extinguishing piece (700) are arranged at an angle of 45 degrees.

6. The arc extinguishing system for a low voltage DC circuit breaker according to claim 1, characterized in that: The inner wall of the arc extinguishing chamber (5) is provided with a plurality of groups of guide plates (10), the plurality of groups of guide plates (10) are distributed in a linear array on the inner wall of the arc extinguishing chamber (5), and the guide plates (10) are arranged in an arc shape.

7. The arc extinguishing system for a low voltage DC circuit breaker according to claim 1, characterized in that: The outer walls of the first arc-extinguishing plate (700), the second arc-extinguishing plate (702) and the third arc-extinguishing plate (704) are all provided with a metal oxide composite coating (16).

8. The arc extinguishing system for a low voltage DC circuit breaker according to claim 1, characterized in that: The fire extinguishing mechanism (8) comprises an ultraviolet flame sensor (804) provided on the inner wall of the arc extinguishing chamber (5), a fire extinguishing tank (800) provided on the inner wall of the arc extinguishing chamber (5), a delivery pipe (801) provided at one end of the fire extinguishing tank (800), a spray plate (802) provided on the inner wall of the arc extinguishing chamber (5), and a plurality of groups of spray nozzles (803) provided on the side wall of the spray plate (802).

9. The arc extinguishing system of a low voltage DC circuit breaker according to claim 8, characterized in that: The spray plate (802) is arranged in an inclined shape in the arc extinguishing chamber (5), and a plurality of groups of spray heads (803) are distributed in a linear array on the side wall of the spray plate (802), and the spray heads (803) are made of aluminum alloy material.

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