Bidirectional pressure self-balancing explosion-proof pressure relief device for energy storage battery box body

Abstract

The invention relates to the technical field of battery safety, in particular to a two-way pressure self-balancing anti-explosion pressure relief device for an energy storage battery box, which comprises a valve seat, a main pressure relief valve, an auxiliary compensation valve, a multi-stage regulating mechanism, an airflow guide mechanism and a reverse locking mechanism, and the multi-stage regulating mechanism is connected with the main pressure relief valve; the airflow guide mechanism is connected with the upper part of the main pressure release valve; the reverse locking mechanism is connected with the main pressure release valve; when a thermal runaway reaction occurs, the multistage adjusting mechanism enables gas to be subjected to asymptotic pressure relief, and the multistage adjusting mechanism is matched with the gas flow guiding mechanism to enable the gas to be subjected to direct flow first and then rotational flow, so that gas flow field autonomous adjustment and pressure gradient slow release are achieved, and the phenomenon that external oxygen flows backwards due to sudden pressure drop is avoided; when the main pressure release valve is opened, the auxiliary compensation valve is locked to prevent oxygen from flowing backwards from the auxiliary compensation valve, so that the problem of explosion caused by oxygen flowing backwards due to quick pressure release under the thermal runaway reaction of the battery is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery safety, and particularly to a two-way pressure self-balancing explosion-proof and pressure-relief device for an energy storage battery box. Background Art

[0002] A two-way pressure self-balancing explosion-proof and pressure-relief device is a device for energy storage battery safety protection. Its main functions are: under normal working conditions, to balance the pressure difference inside and outside the battery system; under abnormal working conditions, to quickly release the internal high pressure or compensate for the external negative pressure, thereby preventing the explosion risk caused by extreme pressure and avoiding structural damage.

[0003] Currently, for the explosion-proof and pressure-relief of battery boxes, mainly the high-pressure gas inside the battery directly acts on the bursting disc to make it rupture and release the high-pressure gas for pressure relief, or the valve is opened when the gas pressure reaches a predetermined value to connect the internal and external gases for pressure relief; however, for these two pressure-relief methods, when the pressure reaches the opening threshold of the pressure-relief valve or the bursting pressure of the bursting disc, the battery has already undergone a thermal runaway decomposition reaction and generated combustible gases such as H2, CO, CH4, and C2H4. At this time, when contacting with oxygen in the outside world, an explosive atmosphere will be formed, causing serious consequences. The prior art has proposed good solutions to this problem. For example, in the lithium battery safety valve pressure-relief device with the patent publication number CN114566751B, pressure relief is controlled by temperature and pressure in coordination. Under normal working conditions, the pre-tightening force between the shape memory alloy sleeve and the first sleeve ensures the sealing performance of the safety valve; when the lithium battery undergoes thermal runaway due to reasons such as short circuit and abuse, the internal temperature of the battery rises rapidly, exceeding the transformation temperature of the shape memory alloy, and the alloy sleeve shrinks, and the pre-tightening force disappears; the internal gas pressure of the battery increases, pushing the end cover to drive the shape memory alloy sleeve to move upward, aligning the first exhaust hole and the second exhaust hole, realizing the gas path connection between the inside of the battery and the outside world, and the gas is discharged; after the pressure relief is completed, the return spring and the pressure-relief spring assembly drive the end cover and the cover plate to return to their original positions respectively; by using the temperature signal as one of the conditions for opening the pressure-relief valve, the internal pressure and volatile electrolyte can be discharged before a large amount of heat is generated during thermal runaway, reducing the reactants participating in the thermal runaway reaction, and avoiding the acceleration of the thermal runaway process by the high pressure inside the battery.

[0004] Although the prior art has solved the problem that the battery has already undergone a thermal runaway reaction to generate combustible gases before pressure relief, there are still the following problems: For a two-way pressure-balancing explosion-proof and pressure-relief device, due to its main air duct for releasing pressure to the outside and auxiliary air duct for compensating inward, during the rapid pressure relief process of the battery thermal runaway reaction, the air pressure inside the battery box will drop suddenly. At this time, the outside gas will backflow into the battery box through the auxiliary air duct for inward compensation of the two-way pressure valve, and at the same time, the outside gas will also enter during the closing process of the main air duct. The oxygen in the outside gas and the remaining combustible gases in the box will be more likely to explode under the high-temperature environment in the box.

[0005] In view of the above situation, in order to overcome the above technical problems, the present invention designs a two-way pressure self-balancing explosion-proof and pressure-relieving device for an energy storage battery box body. Summary of the Invention

[0006] The present invention provides a two-way pressure self-balancing explosion-proof and pressure-relieving device for an energy storage battery box body, which solves the problem of oxygen backflow caused by rapid pressure relief during the thermal runaway reaction of the battery. When a thermal runaway reaction occurs, the multi-stage adjustment mechanism enables the gas to be gradually pressure-relieved, and in cooperation with the air flow guiding mechanism, the gas is in a manner of first direct flow and then swirling flow. The lower-layer stepped linear channel rapidly relieves pressure, and the upper-layer swirling flow balances the pressure, thereby realizing the autonomous adjustment of the gas flow field and the slow release of the pressure gradient, avoiding the phenomenon of external oxygen backflow caused by a sudden drop in pressure. Through the reverse locking mechanism, the auxiliary compensation valve is locked when the main pressure relief valve is opened to prevent oxygen backflow. Moreover, when the main air disk moves upward, it needs to overcome the elastic force of the connecting spring and the pressure generated by the locking slider on the pushing slider under the action of the locking spring, and in cooperation with the deflection degree adjustment of the air flow guiding mechanism, the pressure relief speed in the early stage is further slowed down, so that the pressure relief speed gradually increases, preventing the oxygen backflow caused by too large an instantaneous pressure relief speed.

[0007] To achieve the above object, the present invention provides the following technical solutions: A two-way pressure self-balancing explosion-proof and pressure-relieving device for an energy storage battery box body; including a valve seat, a main pressure relief valve, an auxiliary compensation valve, a multi-stage adjustment mechanism, an air flow guiding mechanism and a reverse locking mechanism; the valve seat is connected to the battery box; the main pressure relief valve is arranged in the valve seat; the auxiliary compensation valve is arranged at the lower part of the valve seat; the multi-stage adjustment mechanism is connected to the main pressure relief valve, and when the main pressure relief valve moves upward, it drives the multi-stage adjustment mechanism to move upward to form a stepped structure; the air flow guiding mechanism is connected to the upper part of the main pressure relief valve, and when the main pressure relief valve moves upward or downward, it drives the air flow guiding mechanism to increase or decrease the angle with the horizontal plane; the reverse locking mechanism is connected to the main pressure relief valve, and when the main pressure relief valve moves upward, it drives the reverse locking mechanism to slide to the position of the auxiliary compensation valve.

[0008] Preferably, the main pressure relief valve includes a partition cylinder, a sliding seat and a main air disk; the partition cylinder is connected to the valve seat, and a sealing ring is arranged at the upper part of the partition cylinder; the sliding seat is connected to the partition cylinder; the main air disk is slidably installed in the sliding seat.

[0009] In the above solution, under normal working conditions, the lower surface of the main air disk presses tightly on the sealing ring to ensure the sealing state, and under the limiting action of the sealing ring, only one-way movement of the main air disk is allowed, so that the main pressure relief valve only allows pressure relief work; when the internal air pressure of the battery box is higher than the external air pressure, the main air disk is pressed to slide upward, so that the upper end surface of the sealing ring and the lower end surface of the main air disk are separated, thereby realizing pressure relief. The air pressure balance channels inside and outside the battery box are designed into two one-way channels through the partition cylinder to ensure that they do not interfere with each other during the air pressure balance process under normal conditions.

[0010] Preferably, the auxiliary compensation valve includes a compensation groove, an auxiliary air disc, a spring groove, and a compensation spring; the compensation groove is formed at the bottom of the partition cylinder; the upper part of the auxiliary air disc is slidably installed in the compensation groove; the spring groove is formed at the bottom of the valve seat; the compensation spring is connected between the spring groove and the auxiliary air disc.

[0011] In the above solution, when the internal air pressure is lower than the external air pressure, the external air pressure will press down the auxiliary air disc, enabling the auxiliary air disc to slide downward to achieve internal and external pressure balance. Moreover, during the process of the main air disc opening for pressure relief, the auxiliary air disc will simultaneously receive an upward pressure, ensuring that the auxiliary air disc has a better self-locking effect during the pressure relief process.

[0012] Preferably, a pressure relief ring surface is provided at the top of the partition cylinder; the cross-section of the pressure relief ring surface is a trapezoidal structure, and the diameter of the upper end of the pressure relief ring surface is greater than that of the lower end, and the diameter of the lower end is equal to the diameter of the upper end of the main air disc.

[0013] In the above solution, through the cooperation between the pressure relief ring surface and the main air disc, exhaust gas will be discharged during the upward sliding process of the main air disc, and the gas flowable area will gradually increase. At the same time, in cooperation with the multi-stage adjustment mechanism, a progressive pressure relief path is formed. When the multi-stage adjustment mechanism relieves pressure in stages, the internal space can be connected to the external space, enabling some gas to be discharged from the internal space, preferentially releasing the local pressure, and avoiding the phenomenon of reverse flow of external oxygen caused by a sudden drop in pressure.

[0014] Preferably, the multi-stage adjustment mechanism includes a first-stage stepped ring, a second-stage stepped ring, and a connecting spring; the first-stage stepped ring is connected to the main air disc; the second-stage stepped ring is fixedly connected to the sliding seat; the connecting spring is connected between the second-stage stepped ring and the first-stage stepped ring.

[0015] In the above solution, when the internal air pressure in the battery box increases, the gas will exert pressure on the main air disc, causing the main air disc to move upward. At this time, the main air disc will drive the first-stage stepped ring to move upward together, and a stepped groove will be formed between the first-stage stepped ring and the second-stage stepped ring. On the one hand, it can increase the internal space of the battery box, gradually release the pressure, avoid a sudden drop in pressure, and reduce the risk of reverse flow of oxygen. On the other hand, during the reset process of the first-stage stepped ring, it can exert pressure on the gas inside the battery box, ensuring that it is still in a continuous state of exhausting gas to the outside during the reset and closing process, avoiding reverse flow of oxygen; in cooperation with the pressure relief ring surface, progressive pressure relief can be achieved.

[0016] Preferably, the air flow guiding mechanism includes a rotating groove, a rotating shaft, a swirling plate, a transmission gear, and a driving rack; the rotating grooves are circumferentially arranged in an array on the inner wall of the sealing ring; the rotating shaft is rotatably installed in the rotating groove; the swirling plate is connected to the rotating shaft; the transmission gear is connected to the rotating shaft; the driving racks are circumferentially arranged in an array on the first-stage stepped ring, and the driving racks and the transmission gear have the same module.

[0017] In the above solution, when the first-stage stepped ring moves upward with the main air disk, the driving rack will move upward and drive the rotating shaft to rotate through the transmission gear. At this time, the angle between the swirling plate and the horizontal plane will increase, causing the spiral angle of the gas to increase. When the internal gas pressure decreases, the spiral angle of the gas will decrease again, making the pressure relief speed increase slowly first and then decrease, avoiding the sudden drop in pressure and temperature mutation caused by rapid pressure relief, reducing the mechanical impact during the pressure relief process, protecting the overall equipment and preventing the backflow of oxygen, and further avoiding the backflow of external gas under the centrifugal force of the discharged gas. The angle change of the swirling plate can be adjusted adaptively according to the internal pressure, and in cooperation with the multi-stage adjustment mechanism, it can achieve rapid pressure relief in the lower-layer straight channel and balanced swirling pressure in the upper layer, thereby realizing the autonomous adjustment of the gas flow field and the slow release of the pressure gradient.

[0018] Preferably, the reverse locking mechanism includes a locking groove, a locking slider, a locking spring, a pushing slider, and a limiting groove; the locking groove is opened on the sliding seat; the locking slider is slidably installed in the locking groove, and a locking inclined surface is provided on the locking slider; the pushing slider is connected to the main air disk, and a pushing inclined surface is provided on the pushing slider; the limiting groove is opened on the auxiliary air disk.

[0019] In the above solution, during the process of the main air disk sliding upward for pressure relief, it will drive the pushing slider to slide upward together. At this time, the pushing inclined surface of the pushing slider and the locking inclined surface of the locking slider are mutually pressed, thereby driving the locking slider to slide and insert into the limiting groove. And during this process, since the pressure relief speed increases slowly first, then rapidly, and finally decreases, the auxiliary air disk will be kept pressed against the bottom of the valve seat at this time, ensuring that the locking slider can be smoothly inserted into the limiting groove to achieve limiting, and ensuring that no external gas backflow will occur during the reset process of the main air disk.

[0020] Preferably, the angle between the pushing inclined surface and the horizontal plane and the angle between the locking inclined surface and the horizontal plane are complementary, and the angle between the locking inclined surface and the horizontal plane is less than 45 degrees.

[0021] In the above solution, when the angle between the locking inclined plane and the horizontal plane is less than 45 degrees, a greater force is required for the pushing inclined plane to push the locking inclined plane so that the locking slider can move horizontally. In the early stage of pressure relief, the upward movement of the main air disk needs to overcome the elastic force of the connecting spring and the pressure exerted by the locking slider on the pushing slider under the action of the locking spring, thereby slowing down the pressure relief speed in the early stage. When the pushing slider moves to the separation of the two inclined planes, only the elastic force of the connecting spring needs to be overcome at this time, thereby increasing the pressure relief speed and enabling the air pressure to be quickly relieved.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Compared with the existing two-way pressure self-balancing explosion-proof pressure relief device for battery boxes, through the multi-stage adjustment mechanism and air flow guiding mechanism provided in the present invention, when the main pressure relief valve is opened, a stepped groove will be formed between the first-stage stepped ring and the second-stage stepped ring to achieve gradual pressure release, avoid sudden pressure drop, reduce the risk of oxygen backflow, and can cooperate with the air flow guiding mechanism to quickly relieve pressure in the lower-layer straight channel and balance the upper-layer swirling pressure, thereby realizing autonomous adjustment of the gas flow field and slow release of the pressure gradient. As the main air disk rises, the angle between the swirling plate and the horizontal plane will increase, increasing the spiral angle of the gas. When the internal gas pressure decreases, the spiral angle of the gas will decrease again, making the pressure relief speed first increase slowly and then decrease, avoiding sudden pressure drop and temperature mutation caused by rapid pressure relief, reducing the mechanical impact during pressure relief, protecting the overall equipment and preventing oxygen backflow.

[0023] 2. Through the reverse locking mechanism of the present invention, when the main pressure relief valve is opened, the upward movement of the main air disk drives the pushing slider to move upward. The pushing slider squeezes the locking inclined plane of the locking slider through the pushing inclined plane, driving the locking slider to slide and insert into the limiting groove, thereby ensuring that the auxiliary compensation valve remains closed when the main pressure relief valve is opened and cannot be opened by external pressure, ensuring that external oxygen will not backflow into the battery box due to sudden pressure drop. In the early stage of pressure relief, the upward movement of the main air disk needs to overcome the elastic force of the connecting spring and the pressure exerted by the locking slider on the pushing slider under the action of the locking spring, thereby slowing down the pressure relief speed in the early stage. When the pushing slider moves to the separation of the two inclined planes, only the elastic force of the connecting spring needs to be overcome at this time, thereby increasing the pressure relief speed and enabling the air pressure to be quickly relieved, thus avoiding sudden pressure drop caused by too fast instantaneous pressure relief speed and further avoiding explosion caused by external oxygen backflow.

[0024] 3. In the present invention, a pressure relief toroidal surface is provided at the top of the partition cylinder, and the diameter of the upper end of the pressure relief toroidal surface is greater than that of the lower end, and the diameter of the lower end is equal to the diameter of the upper end of the main air disk. During the sliding process on the main air disk, exhaust will occur, and the area through which the gas can flow will gradually increase. At the same time, in cooperation with the multi-stage adjustment mechanism, a progressive pressure relief path is formed. When the multi-stage adjustment mechanism relieves pressure in stages, the internal space can be connected to the external space, enabling some gas to be discharged from the internal space, preferentially releasing the local pressure. On the one hand, it can reduce the impact force generated by the air pressure on the main air disk and avoid damage to the main air disk. On the other hand, it can slow down the air pressure and prevent the phenomenon of reverse inflow of external oxygen caused by a sudden drop in pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0026] Figure 1 is the overall structure diagram of the present invention; Figure 2 is the cross-sectional view of the internal structure of the valve seat of the present invention; Figure 3 is the cross-sectional view of the present invention; Figure 4 is Figure 3 the enlarged view of the structure at A in Figure 5 is Figure 3 the enlarged view of the structure at B in Figure 6 is the schematic diagram of the structure of the auxiliary compensation valve of the present invention; Figure 7 is Figure 6 the enlarged view of the structure at C in Figure 8 is the open state diagram of the main pressure relief valve of the present invention; In the figure: 1. Valve seat; 2. Main pressure relief valve; 21. Partition cylinder; 211. Sealing ring; 212. Pressure relief toroidal surface; 22. Sliding seat; 23. Main air disk; 3. Auxiliary compensation valve; 31. Compensation groove; 32. Auxiliary air disk; 33. Spring groove; 34. Compensation spring; 4. Multi-stage adjustment mechanism; 41. First-stage stepped ring; 42. Second-stage stepped ring; 43. Connecting spring; 5. Air flow guiding mechanism; 51. Rotating groove; 52. Rotating shaft; 53. Swirl plate; 54. Transmission gear; 55. Driving rack; 6. Reverse locking mechanism; 61. Locking groove; 62. Locking slider; 621. Locking inclined surface; 63. Locking spring; 64. Pushing slider; 641. Pushing inclined surface; 65. Limiting groove; 7. Battery box. Detailed implementation manners

[0027] To better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings of the specification and specific implementation manners.

[0028] Please refer to Figures 1 to 8 , the present invention provides a two-way pressure self-balancing explosion-proof pressure relief device for an energy storage battery box, and the technical solution is as follows: As a specific implementation manner of the present invention, referring to Figure 1 、 Figure 2 and Figure 8 , a two-way pressure self-balancing explosion-proof pressure relief device for an energy storage battery box; including a valve seat 1, a main pressure relief valve 2, a secondary compensation valve 3, a multi-stage adjustment mechanism 4, an air flow guiding mechanism 5 and a reverse locking mechanism 6; the valve seat 1 is connected to the battery box 7; the main pressure relief valve 2 is arranged in the valve seat 1; the secondary compensation valve 3 is arranged below the valve seat 1; the multi-stage adjustment mechanism 4 is connected to the main pressure relief valve 2, and when the main pressure relief valve 2 moves upward, it drives the multi-stage adjustment mechanism 4 to move upward to form a stepped structure; the air flow guiding mechanism 5 is connected to the upper part of the main pressure relief valve 2, and when the main pressure relief valve 2 moves upward or downward, it drives the air flow guiding mechanism 5 to increase or decrease the angle with the horizontal plane; the reverse locking mechanism 6 is connected to the main pressure relief valve 2, and when the main pressure relief valve 2 moves upward, it drives the reverse locking mechanism 6 to slide to the position of the secondary compensation valve 3 to lock the secondary compensation valve 3, ensuring that the secondary compensation valve 3 remains closed all the time when the main pressure relief valve 2 is opened, and preventing oxygen from flowing back.

[0029] As a specific implementation manner of the present invention, referring to Figure 2 、 Figure 3 and Figure 8, the main pressure relief valve 2 includes a partition cylinder 21, a sliding seat 22 and a main air disk 23; the partition cylinder 21 is connected to the valve seat 1, and a sealing ring 211 is arranged on the upper part of the partition cylinder 21; the sliding seat 22 is connected to the partition cylinder 21; the main air disk 23 is slidably installed in the sliding seat 22. Under normal working conditions, the lower surface of the main air disk 23 presses tightly on the sealing ring 211 to ensure the sealing state, and under the limiting action of the sealing ring 211, only one-way movement of the main air disk 23 is allowed, so that the main pressure relief valve 2 only allows pressure relief work; when the internal pressure in the battery box 7 is higher than the external pressure, the main air disk 23 is pressed to slide upward, so that the upper end surface of the sealing ring 211 and the lower end surface of the main air disk 23 are separated, thereby realizing pressure relief. The air pressure balance channels inside and outside the battery box 7 are designed into two one-way channels through the partition cylinder 21 to ensure that they do not interfere with each other during the air pressure balance process under normal conditions. The auxiliary compensation valve 3 includes a compensation groove 31, an auxiliary air disk 32, a spring groove 33 and a compensation spring 34; the compensation groove 31 is opened at the bottom of the partition cylinder 21; the upper part of the auxiliary air disk 32 is slidably installed in the compensation groove 31; the spring groove 33 is opened at the bottom of the valve seat 1; the compensation spring 34 is connected between the spring groove 33 and the auxiliary air disk 32. When the internal pressure is lower than the external pressure, the external pressure will press down the auxiliary air disk 32, so that the auxiliary air disk 32 can slide downward to achieve internal and external pressure balance, and during the process of the main air disk 23 opening for pressure relief, the auxiliary air disk 32 will be synchronously subjected to an upward pressure, ensuring that the auxiliary air disk 32 has a better self-locking effect during the pressure relief process.

[0030] As a specific embodiment of the present invention, referring to Figure 2 , Figure 3 and Figure 4 , a pressure relief ring surface 212 is arranged at the top of the partition cylinder 21; the cross section of the pressure relief ring surface 212 is a trapezoidal structure, and the diameter of the upper end of the pressure relief ring surface 212 is larger than that of the lower end, and the diameter of the lower end is equal to the diameter of the upper end of the main air disk 23. Through the cooperation between the pressure relief ring surface 212 and the main air disk 23, exhaust will occur during the upward sliding process of the main air disk 23, and the area through which the gas can flow will gradually increase. At the same time, in cooperation with the multi-stage regulating mechanism 4, a progressive pressure relief path is formed. When the multi-stage regulating mechanism 4 relieves pressure in stages, the internal space can be connected to the external space, so that part of the gas can be discharged from the internal space, preferentially releasing the local pressure and avoiding the phenomenon of reverse inflow of external oxygen caused by a sudden drop in pressure.

[0031] As a specific embodiment of the present invention, referring to Figure 3 , Figure 5 , Figure 6 and Figure 8, the multi-stage adjustment mechanism 4 includes a first-stage stepped ring 41, a second-stage stepped ring 42, and a connecting spring 43; the first-stage stepped ring 41 is connected to the main air disk 23; the second-stage stepped ring 42 is fixedly connected to the sliding seat 22; the connecting spring 43 is connected between the second-stage stepped ring 42 and the first-stage stepped ring 41. When the internal air pressure in the battery box 7 increases, the gas will exert pressure on the main air disk 23, causing the main air disk 23 to move upward. At this time, the main air disk 23 will drive the first-stage stepped ring 41 to move upward together, and a stepped groove will be formed between the first-stage stepped ring 41 and the second-stage stepped ring 42. On the one hand, it can increase the internal space of the battery box 7, gradually release the pressure, avoid sudden pressure drop, and reduce the risk of oxygen backflow. On the other hand, it can generate pressure on the internal gas of the battery box during the reset process of the first-stage stepped ring 41, ensuring that it is still in a continuous state of exhausting gas to the outside during the reset and closing process, avoiding oxygen backflow; cooperating with the pressure relief ring surface 212 can achieve progressive pressure relief.

[0032] As a specific embodiment of the present invention, referring to Figure 6 , Figure 7 and Figure 8 , the air flow guiding mechanism 5 includes a rotating groove 51, a rotating shaft 52, a swirl plate 53, a transmission gear 54, and a driving rack 55; the rotating groove 51 is circumferentially and arrayedly opened on the inner wall of the sealing ring 211; the rotating shaft 52 is rotatably installed in the rotating groove 51; the swirl plate 53 is connected to the rotating shaft 52; the transmission gear 54 is connected to the rotating shaft 52; the driving rack 55 is circumferentially and arrayedly arranged on the first-stage stepped ring 41, and the driving rack 55 and the transmission gear 54 have the same module. When the first-stage stepped ring 41 moves upward with the main air disk 23, the driving rack 55 will move upward with the first-stage stepped ring 41 and drive the rotating shaft 52 to rotate through the transmission gear 54. At this time, the angle between the swirl plate 53 and the horizontal plane will increase, increasing the gas spiral lift angle. When the internal gas pressure decreases, it will cause the gas spiral lift angle to decrease again, making the pressure relief speed increase slowly first and then decrease, avoiding sudden pressure drop and temperature mutation caused by rapid pressure relief, reducing the mechanical impact during the pressure relief process, protecting the overall equipment and preventing oxygen backflow. At the same time, under the action of the centrifugal force of the discharged gas, it can further prevent external gas backflow. The angle change of the swirl plate 53 can be adaptively adjusted according to the internal pressure, and cooperating with the multi-stage adjustment mechanism 4, it can achieve rapid pressure relief in the lower-layer straight channel and pressure balance in the upper-layer swirl, thereby realizing autonomous adjustment of the gas flow field and pressure gradient slow release. And the swirl plate 53 can be designed into an arc structure to better fit the installation and ensure the guiding effect on the gas; compared with direct straight-line pressure relief, straight-line first and then swirl can change the gas turbulence dominance to laminar dominance, thereby avoiding oxygen backflow caused by too fast instantaneous pressure relief speed.

[0033] As a specific embodiment of the present invention, referring to Figure 5 andFigure 8 The reverse locking mechanism 6 includes a locking groove 61, a locking slider 62, a locking spring 63, a pushing slider 64 and a limiting groove 65; the locking groove 61 is formed in the sliding seat 22; the locking slider 62 is slidably installed in the locking groove 61, and a locking inclined surface 621 is provided on the locking slider 62; the pushing slider 64 is connected to the main air disc 23, and a pushing inclined surface 641 is provided on the pushing slider 64; the limiting groove 65 is formed in the auxiliary air disc 32. During the process of the main air disc 23 sliding upward to relieve pressure, the pushing slider 64 will be driven to slide upward together. At this time, the pushing inclined surface 641 of the pushing slider 64 presses against the locking inclined surface 621 of the locking slider 62, so as to drive the locking slider 62 to slide and insert into the limiting groove 65. And during this process, since the pressure relief speed first slowly increases, then rapidly increases and finally decreases, at this time the auxiliary air disc 32 will be kept pressed against the bottom of the valve seat 1, so as to ensure that the locking slider 62 smoothly inserts into the limiting groove 65 to achieve limiting, and ensure that no external gas backflow occurs during the reset process of the main air disc 23; when the air pressure received by the main air disc 23 decreases, the main air disc 23 will drive the pushing slider 64 to reset under the pulling force of the connecting spring 43. At this time, the locking spring 63 will drive the locking slider 62 to reset, releasing the locking effect on the auxiliary compensation valve 3, so as to enable the auxiliary compensation valve 3 to perform internal and external air pressure compensation work again during subsequent use.

[0034] As a specific embodiment of the present invention, referring to Figure 5 , Figure 6 and Figure 8 , the included angle between the pushing inclined surface 641 and the horizontal plane is complementary to the included angle between the locking inclined surface 621 and the horizontal plane, and the angle between the locking inclined surface 621 and the horizontal plane is less than 45 degrees. When the angle between the locking inclined surface 621 and the horizontal plane is less than 45 degrees, the component force of the pressure between the locking inclined surface 621 and the pushing inclined surface 641 decomposed in the vertical direction is greater. The pushing inclined surface 641 needs a greater force to push the locking inclined surface 621 so that the locking slider 62 can move horizontally. And the surface roughness of the pushing inclined surface 641 and the locking inclined surface 621 can be appropriately increased to increase the friction between the two. In the early stage of pressure relief, the upward movement of the main air disc 23 needs to overcome the elastic force of the connecting spring 43, the pressure generated by the locking slider 62 on the pushing slider 64 under the action of the locking spring 63, and the friction between the inclined surfaces, so as to slow down the pressure relief speed in the early stage. And when the pushing slider 64 moves to the separation of the two inclined surfaces, at this time only the elastic force of the connecting spring 43 needs to be overcome, so as to increase the pressure relief speed and enable the air pressure to be quickly relieved.

[0035] Working process: When the external air pressure is lower than the internal air pressure of the battery box 7, the main air disc 23 moves upward under the gas pressure. During the upward movement, the first-stage stepped ring 41 will be driven to rise together, forming a stepped groove structure to help the internal gas be discharged gradually. And during the upward movement, the swirl plate 53 will be driven to rotate, and the rotation angle of the swirl plate 53 is adjusted according to the gas pressure. And in cooperation with the multi-stage adjustment mechanism 4, linear pressure relief first and then swirl pressure relief can be achieved, ensuring stable pressure relief and avoiding oxygen backflow caused by too fast pressure relief speed. During the upward movement of the main air disc 23, the reverse locking mechanism 6 will also be driven to lock the auxiliary compensation valve 3 to further prevent oxygen backflow.

[0036] Specifically, when the external air pressure is lower than the internal air pressure of the battery box 7 and a thermal runaway reaction occurs inside the battery box 7, the main air disc 23 moves upward under gas pressure. During the upward movement, it is necessary to overcome the elastic force of the connecting spring 43 and the pressure exerted by the locking slider 62 on the pushing slider 64 under the action of the locking spring 63. The main air disc 23 will drive the first-stage stepped ring 41 to move upward together. A stepped groove will be formed between the first-stage stepped ring 41 and the second-stage stepped ring 42, realizing a gradual release of pressure, avoiding a sudden drop in pressure, and reducing the risk of oxygen backflow. When the first-stage stepped ring 41 moves upward with the main air disc 23, the driving rack 55 will move upward with the first-stage stepped ring 41 and drive the rotating shaft 52 to rotate through the transmission gear 54. At this time, the angle between the swirl plate 53 and the horizontal plane will increase, increasing the gas spiral lift angle, so that the pressure relief speed first slowly increases, then gradually increases rapidly, and finally gradually decreases, avoiding sudden pressure drops and temperature mutations caused by rapid pressure relief, reducing the mechanical impact during pressure relief, protecting the overall equipment and preventing oxygen backflow. At the same time, under the action of the centrifugal force of the discharged gas, it can further prevent external gas from backflowing, and cooperate with the stepped groove formed between the first-stage stepped ring 41 and the second-stage stepped ring 42 to realize rapid pressure relief in the lower-layer straight channel and balanced swirl pressure in the upper layer, thereby realizing autonomous regulation of the gas flow field and slow release of the pressure gradient. And when the locking inclined surface 621 and the pushing inclined surface 641 are separated from each other during the upward movement, the main air disc 23 only needs to overcome the elastic force of the connecting spring 43 to move upward, and rapid pressure relief can be achieved at this time; at the same time, the upward movement of the main air disc 23 will drive the pushing slider 64 to slide upward together. At this time, the pushing slider 64 is squeezed by the pushing inclined surface 641 and the locking inclined surface 621 of the locking slider 62, thereby driving the locking slider 62 to slide and insert into the limiting groove 65, realizing the limiting effect on the auxiliary air disc 32, so as to ensure that the auxiliary compensation valve 3 cannot be opened when the main pressure relief valve 2 is opened, further reducing the risk of oxygen backflow. When the internal gas pressure becomes smaller, under the pulling force of the connecting spring 43, the main air disc 23 will slowly descend. At this time, the angle between the swirl plate 53 and the horizontal plane will decrease, and the first-stage stepped ring 41 will press downward to pressurize the internal gas, so that the gas can maintain a continuous discharge state, avoiding external oxygen from backflowing during the closing process of the main pressure relief valve 2; during the downward movement of the main air disc 23, it will also drive the pushing slider 64 to reset. At this time, the locking spring 63 will drive the locking slider 62 to reset, releasing the locking effect on the auxiliary compensation valve 3, so as to realize that the auxiliary compensation valve 3 can re-perform the internal and external air pressure compensation work in subsequent use.

[0037] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only to illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A bidirectional pressure self-balancing explosion-proof pressure relief device for an energy storage battery box; characterized in that: The invention comprises a valve seat (1), a main pressure relief valve (2), a secondary compensation valve (3), a multi-stage regulating mechanism (4), an airflow guiding mechanism (5) and a reverse locking mechanism (6); the valve seat (1) is connected to a battery box (7); the main pressure relief valve (2) is arranged in the valve seat (1); the secondary compensation valve (3) is arranged at the lower part of the valve seat (1); the multi-stage regulating mechanism (4) is connected to the main pressure relief valve (2); when the main pressure relief valve (2) moves upward, the multi-stage regulating mechanism (4) is driven to move upward to form a stepped structure; the airflow guiding mechanism (5) is connected to the upper part of the main pressure relief valve (2); when the main pressure relief valve (2) moves upward or downward, the airflow guiding mechanism (5) is driven to rotate to increase or decrease the angle between the airflow guiding mechanism (5) and the horizontal plane; the reverse locking mechanism (6) is connected to the main pressure relief valve (2); when the main pressure relief valve (2) moves upward, the reverse locking mechanism (6) is driven to slide to the position of the secondary compensation valve (3).

2. The bidirectional pressure self-balancing explosion-proof pressure relief device for an energy storage battery box according to claim 1, characterized in that: The main pressure relief valve (2) comprises a separation cylinder (21), a sliding seat (22) and a main gas disc (23); the separation cylinder (21) is connected to the valve seat (1), and a sealing ring (211) is provided on the upper part of the separation cylinder (21); the sliding seat (22) is connected to the separation cylinder (21); and the main gas disc (23) is slidably mounted in the sliding seat (22).

3. The bidirectional pressure self-balancing explosion-proof pressure relief device for an energy storage battery box according to claim 2, characterized in that: The auxiliary compensation valve (3) comprises a compensation groove (31), an auxiliary gas disc (32), a spring groove (33) and a compensation spring (34); the compensation groove (31) is provided at the bottom of the separation cylinder (21); the upper part of the auxiliary gas disc (32) is slidably mounted in the compensation groove (31); the spring groove (33) is provided at the bottom of the valve seat (1); and the compensation spring (34) is connected between the spring groove (33) and the auxiliary gas disc (32).

4. The bidirectional pressure self-balancing explosion-proof pressure relief device for an energy storage battery box according to claim 2, characterized in that: A pressure relief annular surface (212) is provided at the top of the separation cylinder (21); the cross section of the pressure relief annular surface (212) is a trapezoidal structure, the diameter of the upper end of the pressure relief annular surface (212) is greater than the diameter of the lower end, and the diameter of the lower end of the pressure relief annular surface (212) is equal to the diameter of the upper end of the main gas disk (23).

5. The bidirectional pressure self-balancing explosion-proof pressure relief device for an energy storage battery box according to claim 2, characterized in that: The multi-stage adjustment mechanism (4) comprises a primary step ring (41), a secondary step ring (42) and a connecting spring (43); the primary step ring (41) is connected to the main gas disk (23); the secondary step ring (42) is fixedly connected to the sliding seat (22); and the connecting spring (43) is connected between the secondary step ring (42) and the primary step ring (41).

6. The bidirectional pressure self-balancing explosion-proof pressure relief device for an energy storage battery box according to claim 5, characterized in that: The airflow guide mechanism (5) comprises a rotating groove (51), a rotating shaft (52), a swirl plate (53), a transmission gear (54) and a driving rack (55); the rotating groove (51) is arranged in a circumferential array on the inner wall of the sealing ring (211); the rotating shaft (52) is rotatably mounted in the rotating groove (51); the swirl plate (53) is connected to the rotating shaft (52); the transmission gear (54) is connected to the rotating shaft (52); the driving rack (55) is arranged in a circumferential array on the primary step ring (41), and the driving rack (55) and the transmission gear (54) have the same module.

7. The bidirectional pressure self-balancing explosion-proof pressure relief device for an energy storage battery box according to claim 3, characterized in that: The reverse locking mechanism (6) comprises a locking groove (61), a locking slider (62), a locking spring (63), a push slider (64) and a limit groove (65); the locking groove (61) is formed on the sliding seat (22); the locking slider (62) is slidably mounted in the locking groove (61), and a locking inclined surface (621) is provided on the locking slider (62); the push slider (64) is connected to the main gas disk (23), and a push inclined surface (641) is provided on the push slider (64); and the limit groove (65) is formed on the auxiliary gas disk (32).

8. The bidirectional pressure self-balancing explosion-proof pressure relief device for an energy storage battery box according to claim 7, characterized in that: The included angle between the pushing inclined surface (641) and the horizontal plane and the included angle between the locking inclined surface (621) and the horizontal plane are complementary, and the angle between the locking inclined surface (621) and the horizontal plane is less than 45 degrees.

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