A bidirectional pressure self-balancing explosion-proof pressure relief device for energy storage battery box

Abstract

The present invention relates to the field of battery safety technology, and specifically to a bidirectional pressure self-balancing explosion-proof pressure relief device for an energy storage battery box, comprising a valve seat, a main pressure relief valve, a secondary compensation valve, a multi-stage adjustment mechanism, an airflow guide mechanism and a reverse locking mechanism, wherein the multi-stage adjustment mechanism is connected to the main pressure relief valve; the airflow guide mechanism is connected to the upper part of the main pressure relief valve; and the reverse locking mechanism is connected to the main pressure relief valve; when a thermal runaway reaction occurs, the multi-stage adjustment mechanism causes the gas to be gradually depressurized, and cooperates with the airflow guide mechanism to cause the gas to flow in a first straight flow and then a swirl flow, thereby realizing autonomous regulation of the gas flow field and slow release of the pressure gradient, avoiding the phenomenon of external oxygen backflow caused by a sudden pressure drop, and through the reverse locking mechanism, locking the secondary compensation valve when the main pressure relief valve is opened to avoid oxygen backflow from the secondary compensation valve, thereby solving the problem of oxygen backflow and explosion caused by rapid pressure relief in the battery thermal runaway reaction.

Description

Technical Field

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

[0002] The bidirectional pressure self-balancing explosion-proof pressure relief device is a device used for the safety protection of energy storage batteries. Its main function is to balance the pressure difference between the inside and outside of the battery system under normal operating conditions, and quickly release the internal high pressure or compensate for the external negative pressure under abnormal operating conditions, thereby preventing the risk of explosion caused by extreme pressure and avoiding structural damage.

[0003] Currently, explosion-proof pressure relief for battery boxes mainly relies on the high-pressure gas in the battery directly acting on the bursting disc, causing it to rupture and release the high-pressure gas to relieve pressure, or opening the valve after the gas pressure reaches a predetermined value, allowing the internal and external gases to communicate and achieve pressure relief. However, with the above two pressure relief methods, when the pressure reaches the pressure relief valve opening threshold or the bursting disc rupture pressure, the battery has already undergone thermal runaway decomposition reaction and produced flammable gases such as H2, CO, CH4, C2H4, etc., which will form an explosive atmosphere after contact with external oxygen, causing serious consequences. The existing technology has proposed good solutions to this problem, such as the lithium battery safety valve pressure relief device with patent publication number CN114566751B. This device uses temperature and pressure to coordinately control pressure relief. Under normal operating conditions, the preload force between the shape memory alloy sleeve and the first sleeve ensures the sealing performance of the safety valve. When the lithium battery experiences thermal runaway due to short circuit, abuse, or other reasons, the internal temperature of the battery rises sharply, exceeding the transformation temperature of the shape memory alloy, causing the alloy sleeve to shrink and the preload force to disappear. The gas pressure inside the battery increases, pushing the end cap and the shape memory alloy sleeve upward, aligning the first and second exhaust holes, achieving gas communication between the interior of the battery and the outside world, and exhausting the gas. After the pressure relief is completed, the return spring and the pressure relief spring assembly respectively drive the end cap and the cover plate to return to their original positions. By using the temperature signal as one of the conditions for opening the pressure relief valve, the internal pressure and volatile electrolyte can be relieved before thermal runaway generates a large amount of heat, reducing the reactants involved in the thermal runaway reaction and preventing the high pressure inside the battery from accelerating the thermal runaway process.

[0004] Although the existing technology has solved the problem of flammable gas generated by thermal runaway reaction in the battery before pressure relief, the following problems still exist: for the explosion-proof pressure relief device with two-way pressure balance, since it has a main air duct for releasing pressure to the outside and a secondary air duct for inward compensation, the air pressure in the battery box will drop sharply during the rapid pressure relief of the battery due to thermal runaway reaction. At this time, the outside gas will flow back into the battery box through the secondary air duct for inward compensation of the two-way pressure valve. At the same time, the main air duct will also cause outside gas to enter during the closing process. The oxygen in the outside gas will mix with the residual flammable gas in the box and 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 bidirectional pressure self-balancing explosion-proof pressure relief device for an energy storage battery box. Summary of the Invention

[0006] The present invention provides a bidirectional pressure self-balancing explosion-proof pressure relief device for an energy storage battery box, which solves the problem of oxygen backflow caused by rapid pressure relief under thermal runaway reaction of the battery. When thermal runaway reaction occurs, the multi-stage regulating mechanism causes the gas to be gradually relieved of pressure, and cooperates with the airflow guiding mechanism to cause the gas to flow in a straight line first and then in a swirl flow. The lower stepped straight channel quickly relieves pressure, and the upper swirl pressure is balanced, thereby realizing autonomous regulation of the gas flow field and slow release of the pressure gradient, avoiding the phenomenon of external oxygen backflow caused by a sudden drop in pressure, and locking the auxiliary compensation valve through the reverse locking mechanism when the main pressure relief valve is opened to avoid oxygen backflow, and the upward movement of the main gas disc needs to overcome the elastic force of the connecting spring and the pressure generated by the locking slider on the push slider under the action of the locking spring, and the deflection adjustment of the airflow guiding mechanism is cooperated to further slow down the early pressure relief speed, so that the pressure relief speed is gradually increased, and the instantaneous pressure relief speed is prevented from being too high and causing oxygen backflow.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A bidirectional pressure self-balancing explosion-proof pressure relief device for an energy storage battery box; comprising a valve seat, a main pressure relief valve, a secondary compensation valve, a multi-stage adjustment mechanism, an airflow guide 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 secondary 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 airflow guide 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 airflow guide 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 secondary compensation valve position.

[0009] Preferably, the main pressure relief valve includes a separation cylinder, a sliding seat and a main gas disc; the separation cylinder is connected to the valve seat, and a sealing ring is provided on the upper part of the separation cylinder; the sliding seat is connected to the separation cylinder; the main gas disc is slidably installed in the sliding seat.

[0010] In the above scheme, under normal working conditions, the lower surface of the main gas disc is pressed against the sealing ring to ensure a sealed state, and the main gas disc is only allowed to move in one direction under the limiting action of the sealing ring, so that the main pressure relief valve is only allowed to perform pressure relief work; when the air pressure inside the battery box is higher than the external air pressure, the main gas disc is pressed to slide upward, so that the upper end face of the sealing ring and the lower end face of the main gas disc are separated, thereby achieving pressure relief, and the air pressure balance channels inside and outside the battery box are designed into two one-way channels through the separation tube to ensure that the two do not interfere with each other during the air pressure balance process under normal conditions.

[0011] Preferably, the auxiliary compensation valve includes a compensation groove, a auxiliary air disc, a spring groove and a compensation spring; the compensation groove is opened at the bottom of the separation cylinder; the upper part of the auxiliary air disc is slidably installed in the compensation groove; the spring groove is opened at the bottom of the valve seat; the compensation spring is connected between the spring groove and the auxiliary air disc.

[0012] In the above scheme, when the internal air pressure is lower than the external air pressure, the external air pressure will press the auxiliary air disc downward, so that the auxiliary air disc can slide downward to achieve internal and external pressure balance, and the auxiliary air disc will be subjected to upward pressure at the same time during the process of the main air disc opening to relieve pressure, ensuring that the auxiliary air disc can better self-lock during the pressure relief process.

[0013] Preferably, a pressure relief annular surface is provided on the top of the separation cylinder; the cross section of the pressure relief annular surface is a trapezoidal structure, and the diameter of the upper end of the pressure relief annular surface is larger than the diameter of the lower end, and the diameter of the lower end is equal to the diameter of the upper end of the main gas disk.

[0014] In the above scheme, through the cooperation between the pressure relief annular surface and the main gas disc, exhaust will be carried out during the sliding process of the main gas disc, and the area where the gas can flow will gradually increase. At the same time, a progressive pressure relief path is formed in conjunction with the multi-stage adjustment mechanism. When the multi-stage adjustment mechanism performs graded pressure relief, the internal space and the external space can be connected, so that part of the gas can be discharged from the internal space, giving priority to releasing local pressure, and avoiding the phenomenon of external oxygen backflow caused by a sudden drop in pressure.

[0015] Preferably, the multi-stage adjustment mechanism includes a primary step ring, a secondary step ring and a connecting spring; the primary step ring is connected to the main air disk; the secondary step ring is fixedly connected to the sliding seat; and the connecting spring is connected between the secondary step ring and the primary step ring.

[0016] In the above scheme, when the air pressure inside the battery box increases, the gas will generate pressure on the main gas disk, causing the main gas disk to move upward. At this time, the main gas disk will drive the first-level step ring to move upward together, and a step groove will be formed between the first-level step ring and the second-level step ring. On the one hand, it can increase the internal space of the battery box, realize gradual pressure release, avoid sudden pressure drop, and reduce the risk of oxygen backflow. On the other hand, by generating pressure on the internal gas of the battery box during the resetting of the first-level step ring, it is ensured that the exhaust is still in a state of continuous external exhaust during the resetting and sealing process, avoiding oxygen backflow; and in conjunction with the pressure relief ring surface, progressive pressure relief can be achieved.

[0017] Preferably, the airflow guide mechanism includes a rotating groove, a rotating shaft, a swirl plate, a transmission gear and a drive rack; the rotating groove circumferential array is opened on the inner wall of the sealing ring; the rotating shaft is rotatably installed in the rotating groove; the swirl plate is connected to the rotating shaft; the transmission gear is connected to the rotating shaft; the drive rack circumferential array is arranged on a first-level stepped ring, and the module of the drive rack is equal to that of the transmission gear.

[0018] In the above scheme, when the first-level stepped ring moves upward with the main gas 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 swirl plate and the horizontal plane will increase, so that the gas spiral rise angle will increase. When the internal gas pressure decreases, the gas spiral rise angle will decrease again, so that the pressure relief speed will first slowly increase and then decrease, avoiding the sudden pressure drop and temperature mutation caused by rapid pressure relief, reducing the mechanical impact during the pressure relief process, protecting the entire equipment and preventing oxygen backflow, and further avoiding the backflow of external gas under the action of the centrifugal force of the exhaust gas. The angle change of the swirl plate can be adaptively adjusted according to the internal pressure, and cooperate with the multi-stage adjustment mechanism to achieve rapid pressure relief in the lower straight channel and balanced pressure in the upper swirl, thereby realizing autonomous adjustment of the gas flow field and slow release of the pressure gradient.

[0019] Preferably, the reverse locking mechanism includes a locking groove, a locking slider, a locking spring, a push slider and a limit groove; the locking groove is provided 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 push slider is connected to the main air disk, and a push inclined surface is provided on the push slider; the limit groove is provided on the auxiliary air disk.

[0020] In the above scheme, when the main gas disc slides upward to relieve pressure, it will drive the push slider to slide upward together. At this time, the push slider is squeezed against the locking slope of the locking slider through the pushing slope, thereby driving the locking slider to slide into the limit groove. In this process, since the pressure relief speed first increases slowly, then increases rapidly and finally decreases, the auxiliary gas disc will be kept pressed against the bottom of the valve seat, thereby ensuring that the locking slider is smoothly inserted into the limit groove to achieve limitation, and ensuring that external gas backflow does not occur during the resetting of the main gas disc.

[0021] Preferably, the angle between the sliding slope and the horizontal plane is complementary to the angle between the locking slope and the horizontal plane, and the angle between the locking slope and the horizontal plane is less than 45 degrees.

[0022] In the above scheme, when the angle between the locking slope and the horizontal plane is less than 45 degrees, the sliding slope needs a greater force to push the locking slope so that the locking slider can move horizontally. In the early stage of pressure relief, the upward movement of the main air disc 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, thereby slowing down the early pressure relief speed. When the pushing slider moves to the separation of the two slopes, it only needs to overcome the elastic force of the connecting spring, thereby increasing the pressure relief speed and allowing the air pressure to be quickly released.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. Compared with the existing bidirectional pressure self-balancing explosion-proof pressure relief device for battery boxes, the present invention has a multi-stage adjustment mechanism and an airflow guide mechanism. When the main pressure relief valve is opened, a stepped groove will be formed between the first-level stepped ring and the second-level stepped ring, so as to gradually release the pressure, avoid a sudden pressure drop, and reduce the risk of oxygen backflow. In addition, it can cooperate with the airflow guide mechanism to quickly relieve the pressure in the lower straight channel and balance the pressure of the upper vortex, thereby realizing autonomous regulation of the gas flow field and slow release of the pressure gradient. Moreover, as the main gas disc rises, the angle between the vortex plate and the horizontal plane will increase, so that the gas spiral rise angle increases. When the internal gas pressure decreases, the gas spiral rise angle will decrease again, so that the pressure relief speed first increases slowly and then decreases, avoiding a sudden pressure drop and temperature mutation caused by rapid pressure relief, reducing mechanical impact during the pressure relief process, protecting the entire equipment and preventing oxygen backflow.

[0025] When the cam is in the closed position, the cam is in the closed position and the cam is in the closed position, so that the cam is in the closed position and the cam is in the closed position, thereby preventing the cam from being opened by the cam and the cam from being opened.

[0026] 3. The present invention provides a pressure relief annular surface on the top of the partition tube, and the upper diameter of the pressure relief annular surface is larger than the lower diameter, and the lower diameter is equal to the upper diameter of the main gas disk. During the sliding of the main gas disk, exhaust will be carried out, and the area where the gas can circulate will gradually increase. At the same time, a progressive pressure relief path is formed in conjunction with the multi-stage adjustment mechanism. When the multi-stage adjustment mechanism performs graded pressure relief, the internal space can be connected with the external space, so that part of the gas can be discharged from the internal space, and the local pressure is released first. On the one hand, it can reduce the impact force of the air pressure on the main gas disk and avoid damage to the main gas disk. On the other hand, it can slowly release the air pressure to avoid the phenomenon of external oxygen backflow caused by a sudden drop in pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 It is the overall structural diagram of the present invention;

[0029] Figure 2 This is a cross-sectional view of the internal structure of the valve seat of the present invention;

[0030] Figure 3 is a cross-sectional view of the present invention;

[0031] Figure 4 for Figure 3 A magnified view of the structure at center A;

[0032] Figure 5 for Figure 3 A magnified view of the structure at point B in the middle;

[0033] Figure 6 This is a schematic structural diagram of the auxiliary compensation valve of the present invention;

[0034] Figure 7 for Figure 6 A magnified view of the structure at point C in the middle;

[0035] Figure 8 This is a diagram of the main pressure relief valve in the open state of the present invention;

[0036] In the figure: 1. Valve seat; 2. Main pressure relief valve; 21. Separation cylinder; 211. Sealing ring; 212. Pressure relief ring surface; 22. Sliding seat; 23. Main air disc; 3. Auxiliary compensation valve; 31. Compensation groove; 32. Auxiliary air disc; 33. Spring groove; 34. Compensation spring; 4. Multi-stage adjustment mechanism; 41. First-stage step ring; 42. Second-stage step ring; 43. Connecting spring; 5. Air flow guide mechanism; 51. Rotating groove; 52. Rotating shaft; 53. Swirl plate; 54. Transmission gear; 55. Drive rack; 6. Reverse locking mechanism; 61. Locking groove; 62. Locking slider; 621. Locking inclined surface; 63. Locking spring; 64. Push slider; 641. Push inclined surface; 65. Limiting groove; 7. Battery box. DETAILED DESCRIPTION

[0037] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0038] See also Figures 1 to 8 The present invention provides a bidirectional pressure self-balancing explosion-proof pressure relief device for an energy storage battery box, and the technical solution is as follows:

[0039] As a specific embodiment of the present invention, refer to Figure 1 、 Figure 2 and Figure 8 , a bidirectional pressure self-balancing explosion-proof pressure relief device for an energy storage battery box; it includes a valve seat 1, a main pressure relief valve 2, a secondary compensation valve 3, a multi-stage adjustment mechanism 4, an airflow guide 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 at the lower part of 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 airflow guide mechanism 5 is connected to the upper part of the main pressure relief valve 2, and when the main pressure relief valve 2 moves up or down, it drives the airflow guide mechanism 5 to increase or decrease the angle between it and 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, locking the secondary compensation valve 3, ensuring that the secondary compensation valve 3 remains in a closed state when the main pressure relief valve 2 is opened, thereby preventing oxygen backflow.

[0040] As a specific embodiment of the present invention, refer to Figure 2 、 Figure 3 and Figure 8 The main pressure relief valve 2 includes 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 installed in the sliding seat 22. Under normal working conditions, the lower surface of the main gas disc 23 is pressed against the sealing ring 211 to ensure a sealed state, and under the limiting action of the sealing ring 211, the main gas disc 23 is only allowed to move in one direction, so that the main pressure relief valve 2 is only allowed to perform pressure relief work; when the internal air pressure of the battery box 7 is higher than the external air pressure, the main gas disc 23 is pressed and slides upward, so that the upper end surface of the sealing ring 211 and the lower end surface of the main gas disc 23 are separated, thereby achieving pressure relief. The internal and external air pressure balance channels of the battery box 7 are designed into two one-way channels through the separation cylinder 21 to ensure that the two do not interfere with each other during the air pressure balance process under normal conditions. The auxiliary compensating valve 3 includes a compensating groove 31, an auxiliary air disc 32, a spring groove 33, and a compensating spring 34. The compensating groove 31 is located at the bottom of the separating cylinder 21. The upper portion of the auxiliary air disc 32 is slidably mounted within the compensating groove 31. The spring groove 33 is located at the bottom of the valve seat 1. The compensating spring 34 is connected between the spring groove 33 and the auxiliary air disc 32. When the internal air pressure is lower than the external air pressure, the external air pressure will press the auxiliary air disc 32 downward, allowing it to slide downward to achieve internal and external pressure balance. Furthermore, when the main air disc 23 opens to release pressure, the auxiliary air disc 32 is simultaneously subjected to upward pressure, ensuring that the auxiliary air disc 32 can better self-lock during the pressure release process.

[0041] As a specific embodiment of the present invention, refer to Figure 2 、 Figure 3 and Figure 4 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 trapezoidal, and the diameter of the upper end of the pressure relief annular surface 212 is larger than the diameter of the lower end, which is equal to the diameter of the upper end of the main gas disk 23. Through the cooperation between the pressure relief annular surface 212 and the main gas disk 23, exhaust will be carried out as the main gas disk 23 slides upward, and the area through which gas can circulate will gradually increase. At the same time, in conjunction with the multi-stage adjustment mechanism 4, a progressive pressure relief path is formed. When the multi-stage adjustment mechanism 4 performs staged pressure relief, it can connect the internal space with the external space, allowing some gas to be discharged from the internal space, preferentially releasing local pressure and avoiding the phenomenon of external oxygen backflow caused by a sudden pressure drop.

[0042] As a specific embodiment of the present invention, refer to Figure 3 、 Figure 5 、 Figure 6 and Figure 8The multi-stage adjustment mechanism 4 includes a primary stepped ring 41, a secondary stepped ring 42, and a connecting spring 43. The primary stepped ring 41 is connected to the main gas disk 23; the secondary stepped ring 42 is fixedly connected to the sliding seat 22; and the connecting spring 43 is connected between the secondary stepped ring 42 and the primary stepped ring 41. When the air pressure inside the battery box 7 increases, the gas will exert pressure on the main gas disk 23, causing the main gas disk 23 to move upward. At this time, the main gas disk 23 will drive the primary stepped ring 41 to move upward together, forming a stepped groove between the primary stepped ring 41 and the secondary stepped ring 42. On the one hand, this can increase the internal space of the battery box 7, gradually release the pressure, avoid a sudden pressure drop, and reduce the risk of oxygen backflow. On the other hand, by generating pressure on the gas inside the battery box during the reset process of the primary stepped ring 41, it can ensure that the gas is continuously exhausted during the reset and closure process, thus preventing oxygen backflow. In combination with the pressure relief ring surface 212, gradual pressure relief can be achieved.

[0043] As a specific embodiment of the present invention, refer to Figure 6 、 Figure 7 and Figure 8 The airflow guide 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 arranged in a circumferential array 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 arranged in a circumferential array on the primary stepped ring 41, and the module of the driving rack 55 is equal to that of the transmission gear 54. When the primary stepped ring 41 moves upward with the main gas disk 23, the driving rack 55 will move upward with the primary 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, so that the gas spiral rise angle will increase. When the internal gas pressure decreases, the gas spiral rise angle will decrease again, so that the pressure relief speed will first increase slowly and then decrease, avoiding the pressure drop and temperature mutation caused by rapid pressure relief, reducing the mechanical impact during the pressure relief process, protecting the entire equipment and preventing oxygen backflow. At the same time, The centrifugal force of the exhaust gas can further prevent the backflow of external gas. The angle change of the swirl plate 53 can be adaptively adjusted according to the internal pressure, and cooperate with the multi-stage adjustment mechanism 4 to achieve rapid pressure relief in the lower straight channel and pressure balance in the upper swirl, thereby realizing autonomous adjustment of the gas flow field and slow release of the pressure gradient. The swirl plate 53 can be designed into an arc structure for better installation and to ensure the guiding effect on the gas. Compared with direct linear pressure relief, the linear flow followed by the swirl can change the gas turbulence dominance into laminar flow dominance, thereby avoiding the oxygen backflow caused by the instantaneous pressure relief speed being too fast.

[0044] As a specific embodiment of the present invention, refer to Figure 5 and Figure 8 The reverse locking mechanism 6 includes 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 provided on 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 push slider 64 is connected to the main air disk 23, and a push inclined surface 641 is provided on the push slider 64; the limit groove 65 is provided on the auxiliary air disk 32. When the main air disc 23 slides upward to release the pressure, it will drive the push slider 64 to slide upward together. At this time, the push slider 64 is squeezed against the locking slope 621 of the locking slider 62 by the push slope 641, thereby driving the locking slider 62 to slide into the limit groove 65. In this process, since the pressure relief speed first increases slowly, then increases rapidly and finally decreases, the auxiliary air disc 32 will be kept pressed against the bottom of the valve seat 1, thereby ensuring that the locking slider 62 is smoothly inserted into the limit groove 65 to achieve limit, ensuring that external air backflow will not occur during the resetting of the main air disc 23; when the air pressure on the main air disc 23 is reduced, the main air disc 23 will drive the push slider 64 to return to its original position under the tension of the connecting spring 43. At this time, the locking spring 63 will drive the locking slider 62 to return to its original position, releasing the locking effect on the auxiliary compensation valve 3, so that the auxiliary compensation valve 3 can perform internal and external air pressure compensation again in subsequent use.

[0045] As a specific embodiment of the present invention, refer to Figure 5 、 Figure 6 and Figure 8 The included angle between the pushing slope 641 and the horizontal plane is complementary to the included angle between the locking slope 621 and the horizontal plane, and the angle between the locking slope 621 and the horizontal plane is less than 45 degrees. When the angle between the locking slope 621 and the horizontal plane is less than 45 degrees, the pressure between the locking slope 621 and the pushing slope 641 is decomposed into a larger component in the vertical direction. The pushing slope 641 needs a greater force to push the locking slope 621 so that the locking slider 62 can move horizontally, and the pushing slope 641 is not as strong as the locking slope 621. The surface roughness of 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 gas disc 23 needs to overcome the elastic force of the connecting spring 43 and the pressure generated by the locking slider 62 on the push slider 64 under the action of the locking spring 63, as well as the friction between the inclined surfaces, thereby slowing down the early pressure relief speed. When the push slider 64 moves to the point where the two inclined surfaces are separated, it only needs to overcome the elastic force of the connecting spring 43, thereby increasing the pressure relief speed and allowing the air pressure to be quickly released.

[0046] Working process: When the external air pressure is lower than the internal air pressure of the battery box 7, the main gas disc 23 moves upward under the gas pressure. During the rising process, it will drive the first-level step ring 41 to rise together to form a step groove structure, which helps the internal gas to be discharged gradually. In addition, during the rising process, it will drive the swirl plate 53 to rotate. The rotation angle of the swirl plate 53 is adjusted according to the gas pressure. In combination with the multi-stage adjustment mechanism 4, linear pressure relief and then swirl pressure relief can be achieved, ensuring stable pressure relief and avoiding oxygen backflow caused by excessive pressure relief speed. During the rising process of the main gas disc 23, the reverse locking mechanism 6 will also be driven to lock the auxiliary compensation valve 3 to further prevent oxygen backflow.

[0047] 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 gas disc 23 moves upward under the gas pressure. During the upward movement, it is necessary to overcome the elastic force of the connecting spring 43 and the pressure generated by the locking slider 62 on the push slider 64 under the action of the locking spring 63. The main gas disc 23 will drive the primary step ring 41 to move upward together, and a step groove will be formed between the primary step ring 41 and the secondary step ring 42 to gradually release the pressure, avoid a sudden drop in pressure, and reduce the risk of oxygen backflow. When the primary step ring 41 moves upward with the main gas disc 23, the driving rack 55 will move upward with the primary step 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, so that the gas spiral rise angle increases, so that the pressure relief speed will first increase slowly, then gradually increase rapidly, and finally decrease gradually, avoiding a sudden drop in pressure and a sudden change in temperature caused by rapid pressure relief, reducing The mechanical impact during the small pressure relief process protects the entire equipment and prevents oxygen backflow. At the same time, under the action of the centrifugal force of the exhaust gas, it can further prevent the backflow of external gas. In conjunction with the step groove formed between the first-level step ring 41 and the second-level step ring 42, it can achieve rapid pressure relief in the lower linear channel and balance the pressure of the upper swirl, thereby achieving autonomous regulation of the gas flow field and slow release of the pressure gradient. When the locking slope 621 and the push slope 641 are separated from each other, the main gas disc 23 only needs to overcome the elastic force of the connecting spring 43 to rise, and rapid pressure relief can be achieved at this time. At the same time, the rise of the main gas disc 23 will drive the push slider 64 to slide upward together. At this time, the push slider 64 is squeezed against the locking slope 621 of the locking slider 62 by the push slope 641, thereby driving the locking slider 62 to slide into the limit groove 65, achieving a limiting effect on the auxiliary gas disc 32, thereby ensuring 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 gas disc 23 will slowly descend. At this time, the angle between the swirl plate 53 and the horizontal plane will decrease, and the first-level stepped ring 41 will press down to pressurize the internal gas, so that the gas can maintain a continuous discharge state, avoiding the backflow of external oxygen during the closing process of the main pressure relief valve 2; during the descending process of the main gas disc 23, it will also drive the push 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 that the auxiliary compensation valve 3 can resume the internal and external air pressure compensation work in subsequent use.

[0048] The basic principles, main features, and advantages of the present invention are shown and described above. It should be understood by those skilled in the art that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention as claimed, which 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 by: 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 air flow 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 air flow 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 air flow guiding mechanism (5) is driven to rotate to increase or decrease the angle between the air flow 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); 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 portion of the separation cylinder (21); the sliding seat (22) is connected to the separation cylinder (21); the main gas disc (23) is slidably mounted in the sliding seat (22); The auxiliary compensation valve (3) comprises a compensation groove (31), an auxiliary air 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 portion of the auxiliary air disc (32) is slidably mounted in the compensation groove (31); the spring groove (33) is provided at the bottom of the valve seat (1); the compensation spring (34) is connected between the spring groove (33) and the auxiliary air disc (32); The reverse locking mechanism (6) comprises a locking groove (61), a locking slider (62), a locking spring (63), a push slider (64) and a limiting groove (65); the locking groove (61) is provided 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 air disk (23), and a push inclined surface (641) is provided on the push slider (64); and the limiting groove (65) is provided on the auxiliary air disk (32).

2. The bidirectional pressure self-balancing explosion-proof pressure relief device for an energy storage battery box according to claim 1, characterized in that: A pressure relief annular surface (212) is provided on the top of the separation cylinder (21); the cross section of the pressure relief annular surface (212) is a trapezoidal structure, and the diameter of the upper end of the pressure relief annular surface (212) is larger 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).

3. The bidirectional pressure self-balancing explosion-proof pressure relief device for an energy storage battery box according to claim 1, characterized in that: The multi-stage adjustment mechanism (4) comprises a primary stepped ring (41), a secondary stepped ring (42) and a connecting spring (43); the primary stepped ring (41) is connected to the main gas disk (23); the secondary stepped ring (42) is fixedly connected to the sliding seat (22); and the connecting spring (43) is connected between the secondary stepped ring (42) and the primary stepped ring (41).

4. The bidirectional pressure self-balancing explosion-proof pressure relief device for an energy storage battery box according to claim 3, 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 stepped ring (41), and the module of the driving rack (55) is equal to that of the transmission gear (54).

5. The bidirectional pressure self-balancing explosion-proof pressure relief device for an energy storage battery box according to claim 1, 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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