Pressure relief device, thermal runaway prevention unit, energy storage system and control method

Abstract

The present invention relates to the field of energy storage safety technology, and in particular to a pressure relief device, an anti-thermal runaway unit, an energy storage system and a control method. The pressure relief device includes a pressure relief seat and a pressure relief core. The pressure relief seat is inserted into the assembly hole of the shell. A through hole is opened in the pressure relief seat. One end of the through hole is connected to the medicine chamber, and the other end is connected to the outside of the shell. The pressure relief core is arranged in the through hole to block the through hole. The melting temperature of the pressure relief core is higher than the preset temperature and lower than the upper safety limit temperature after the thermal runaway of the energy storage unit. The anti-thermal runaway unit includes a shell and the above-mentioned pressure relief device. The energy storage system includes an energy storage unit, a control unit, a detection unit and the above-mentioned anti-thermal runaway unit. The detection unit includes a temperature sensor. The temperature sensor is used to detect the temperature of the energy storage unit. The control unit is communicatively connected with the temperature sensor and the puncture valve of the anti-thermal runaway unit. The control unit can control the action of the puncture valve according to the detection result of the temperature sensor. The control method is applied to the above-mentioned energy storage system.

Description

Technical Field

[0001] The present invention relates to the field of energy storage safety technology, and in particular to a pressure relief device, a thermal runaway prevention unit, an energy storage system and a control method. Background Art

[0002] Thermal runaway prevention units are installed in energy storage systems such as battery systems to cool down or flame retard the battery cells when the temperature of the battery cells rises to a certain temperature, ensuring the safe use of the battery system. The thermal runaway prevention unit lowers the temperature of the battery cells or prevents the battery cells from burning by spraying out agents. An injection valve is installed at the injection port of the thermal runaway prevention unit. The agent can only be sprayed out when the pressure is higher than the preset pressure, resulting in a certain pressure of gas remaining inside and unable to be sprayed out. Once the temperature of the battery cells rises out of control, the high temperature environment will cause the gas pressure in the thermal runaway prevention unit to rise rapidly, and the speed at which the gas is released from the injection valve is slower than the speed at which the gas pressure increases, resulting in the risk of explosion of the thermal runaway prevention unit.

[0003] Therefore, there is an urgent need for a pressure relief device, a thermal runaway prevention unit, an energy storage system and a control method to solve the above problems. Summary of the invention

[0004] An object of the present invention is to provide a pressure relief device that can prevent the explosion of the thermal runaway prevention unit in a high temperature environment and ensure the safety of the thermal runaway prevention unit.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A pressure relief device is provided to ensure the safety of use of a thermal runaway prevention unit, wherein the thermal runaway prevention unit comprises a shell, wherein a medicine chamber is provided in the shell, and when an energy storage unit reaches a preset temperature, the medicine in the medicine chamber is sprayed toward the energy storage unit, and the pressure relief device comprises:

[0007] A pressure relief seat, the pressure relief seat is inserted into the assembly hole of the shell, a through hole is formed in the pressure relief seat, one end of the through hole is connected to the medicine chamber, and the other end is connected to the outside of the shell;

[0008] A pressure relief core is arranged in the through hole to block the through hole, the melting temperature of the pressure relief core is higher than the preset temperature, and the melting temperature is lower than the safety upper limit temperature after the thermal runaway of the energy storage unit.

[0009] Optionally, a groove is formed at one end of the pressure relief core close to the medicine chamber, and the groove extends along the axial depth of the pressure relief core.

[0010] Optionally, one end of the pressure relief core away from the medicine chamber has a curved surface protruding structure, and the curved surface protruding structure protrudes in a direction away from the medicine chamber.

[0011] Optionally, the pressure relief device further comprises a first sealing ring, the pressure relief seat comprises a main body and a pressing protrusion, the first sealing ring is sleeved on the main body, the main body is partially inserted into the assembly hole, the diameter of the pressing protrusion is larger than the inner diameter of the assembly hole, and the first sealing ring is pressed between the pressing protrusion and the housing;

[0012] And / or, the pressure relief device further includes a second sealing ring, the second sealing ring is sleeved on the pressure relief core, and the second sealing ring is used for forming a circumferential seal between the pressure relief core and the inner wall of the through hole.

[0013] Optionally, a first limiting protrusion is provided around the inner wall of the through hole, and the pressure relief core is closer to the medicine chamber than the first limiting protrusion;

[0014] And / or, a second limiting protrusion is arranged around the inner wall of the through hole, and the pressure relief core is farther away from the medicine chamber than the second limiting protrusion.

[0015] Another object of the present invention is to provide a thermal runaway prevention unit that can prevent explosions in high temperature environments and ensure its safety in use.

[0016] To achieve this object, the present invention adopts the following technical solutions:

[0017] A thermal runaway prevention unit is provided, comprising a housing and the above-mentioned pressure relief device.

[0018] Optionally, the thermal runaway prevention unit further includes an injection valve, which is arranged at the injection port of the shell. The shell also has a driving gas chamber, in which a driving gas is contained. The injection pressure of the injection valve is greater than a preset pressure of the agent, and the injection pressure is less than a preset pressure of the driving gas, so that the driving gas can drive the agent to be ejected from the injection valve.

[0019] Optionally, the thermal runaway prevention unit further comprises a puncture valve, a blocking piece is provided between the driving gas chamber and the medicine chamber, and the puncture valve can puncture the blocking piece to allow the driving gas chamber to communicate with the medicine chamber.

[0020] Another object of the present invention is to provide an energy storage system that can prevent the explosion of the thermal runaway prevention unit in a high temperature environment and ensure the safety of the use of the thermal runaway prevention unit.

[0021] To achieve this object, the present invention adopts the following technical solutions:

[0022] An energy storage system is provided, comprising an energy storage unit, a control unit, a detection unit and the above-mentioned thermal runaway protection unit, wherein the detection unit comprises a temperature sensor, and the temperature sensor is used to detect the temperature of the energy storage unit. The control unit is communicatively connected with the temperature sensor and the puncture valve of the thermal runaway protection unit, and the control unit can control the action of the puncture valve according to the detection result of the temperature sensor.

[0023] Another object of the present invention is to provide a control method, which can prevent the explosion of the thermal runaway prevention unit in a high temperature environment and ensure the safety of the use of the thermal runaway prevention unit.

[0024] To achieve this object, the present invention adopts the following technical solutions:

[0025] A control method is provided, which is applied to the above energy storage system, and the control method comprises the following steps:

[0026] It is determined whether the temperature of the energy storage unit reaches the preset temperature. If so, the control unit controls the puncture valve to puncture the blocking member so that the driving gas driving agent of the thermal runaway prevention unit is ejected toward the energy storage unit. When the temperature at the thermal runaway prevention unit is higher than the melting temperature of the pressure relief core, the pressure relief core melts, and the gas in the thermal runaway prevention unit is completely released.

[0027] Beneficial effects of the present invention:

[0028] The present invention provides a pressure relief device for ensuring the safety of use of a thermal runaway prevention unit. The thermal runaway prevention unit includes a shell, and a medicine chamber is provided in the shell. When the energy storage unit reaches a preset temperature, the medicine in the medicine chamber is sprayed toward the energy storage unit. The pressure relief device includes a pressure relief seat and a pressure relief core, wherein the pressure relief seat is inserted into the assembly hole of the shell, and a through hole is provided in the pressure relief seat, one end of the through hole is connected to the medicine chamber, and the other end is connected to the outside of the shell. The pressure relief core is arranged in the through hole to seal the through hole. The melting temperature of the pressure relief core is higher than the preset temperature, that is, the pressure relief core will not melt before the agent is sprayed out, so as to prevent the agent from being unable to be accurately sprayed from the injection port toward the energy storage unit, and the melting temperature of the pressure relief core is lower than the safety upper limit temperature after the thermal runaway of the energy storage unit, that is, after the agents are all sprayed out, if the temperature of the energy storage unit continues to rise, the remaining gas inside the agent cavity will rapidly heat up at this time, posing a safety hazard. When the temperature does not reach the safety upper limit temperature, the pressure relief core will melt, causing the agent cavity to be connected to the outside of the shell, and the remaining gas will be released to the outside of the shell, thereby eliminating the risk of explosion of the thermal runaway protection unit and ensuring its safety in use.

[0029] The present invention further provides a thermal runaway prevention unit, comprising a housing and the above-mentioned pressure relief device. The thermal runaway prevention unit can prevent explosion in a high temperature environment and ensure its safety in use.

[0030] The present invention further provides an energy storage system, including an energy storage unit, a control unit, a detection unit and the above-mentioned thermal runaway prevention unit, wherein the detection unit includes a temperature sensor, the temperature sensor is used to detect the temperature of the energy storage unit, the control unit is communicatively connected with the temperature sensor and the puncture valve of the thermal runaway prevention unit, and the control unit can control the action of the puncture valve according to the detection result of the temperature sensor. The energy storage system can prevent the thermal runaway prevention unit from exploding in a high temperature environment, and ensure the safety of the use of the thermal runaway prevention unit.

[0031] The present invention also provides a control method, which is applied to the above energy storage system. The control method includes the following steps: judging whether the temperature of the energy storage unit reaches the preset temperature, if so, the control unit controls the puncture valve to puncture the blocking member, so that the driving gas of the anti-thermal runaway unit drives the agent to spray toward the energy storage unit, and when the temperature at the anti-thermal runaway unit is higher than the melting temperature of the pressure relief core, the pressure relief core melts, and the gas in the anti-thermal runaway unit is completely released. The above energy storage system can prevent the explosion of the anti-thermal runaway unit in a high temperature environment by applying the control method, and ensure the safety of the use of the anti-thermal runaway unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic structural diagram of a thermal runaway prevention unit provided by an embodiment of the present invention from a first perspective;

[0033] Figure 2 is a schematic structural diagram of a pressure relief device provided in an embodiment of the present invention;

[0034] Figure 3 is a cross-sectional view of a pressure relief device provided by an embodiment of the present invention;

[0035] Figure 4 is a structural schematic diagram of a thermal runaway prevention unit provided by an embodiment of the present invention from a second viewing angle;

[0036] Figure 5 yes Figure 4 Middle AA section view;

[0037] Figure 6 is a schematic structural diagram of a thermal runaway prevention unit provided by an embodiment of the present invention from a third perspective;

[0038] Figure 7 yes Figure 6 Middle BB section view.

[0039] In the figure:

[0040] 1. pressure relief device; 11. pressure relief seat; 111. main body; 1111. external thread; 112. pressing protrusion; 113. first limit protrusion; 12. pressure relief core; 121. groove; 122. curved protrusion structure; 13. first sealing ring; 14. second sealing ring;

[0041] 2. Shell; 21. Medicine chamber; 22. Driving gas chamber; 23. Third passage;

[0042] 3. Puncture the valve. DETAILED DESCRIPTION

[0043] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and implementation methods. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings, rather than all of them.

[0044] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0046] like Figure 1-Figure 3 As shown, the pressure relief device 1 of this embodiment is used to ensure the safety of the use of the thermal runaway prevention unit. The thermal runaway prevention unit includes a shell 2, and the shell 2 has a medicine chamber 21. When the energy storage unit reaches a preset temperature, that is, when there is a certain safety risk, the medicine in the medicine chamber 21 will be sprayed toward the energy storage unit to cool down or flame retard the energy storage unit, so that the energy storage unit returns to a normal temperature range, or blocks the spread of thermal runaway, or delays the spread of thermal runaway.

[0047] The pressure relief device 1 includes a pressure relief seat 11 and a pressure relief core 12, wherein the pressure relief seat 11 is inserted into the assembly hole of the housing 2, and a through hole is formed in the pressure relief seat 11, one end of the through hole is connected to the medicine chamber 21, and the other end is connected to the outside of the housing 2. The pressure relief core 12 is arranged in the through hole to block the through hole, and the melting temperature of the pressure relief core 12 is higher than the preset temperature, that is, the pressure relief core 12 will not melt before the medicine is sprayed out, so as to prevent the medicine from being sprayed out from the pressure relief device 1 instead of being sprayed out accurately from the spray port toward the energy storage unit. Moreover, the melting temperature of the pressure relief core 12 is lower than the upper safety limit temperature after thermal runaway of the energy storage unit. That is, after all the reagents are sprayed out, if the temperature of the energy storage unit continues to rise, the remaining gas inside the reagent chamber 21 will heat up rapidly, posing a potential safety hazard. When the temperature does not reach the upper safety limit temperature, the pressure relief core 12 will melt, causing the reagent chamber 21 to communicate with the outside of the shell 2, and the remaining gas will be released to the outside of the shell 2. That is, when the energy storage unit has not reached the upper safety limit temperature and the temperature rise of the thermal runaway protection unit is delayed, that is, when the temperature of the thermal runaway protection unit still has a certain temperature difference with the upper safety limit temperature, the risk of explosion of the thermal runaway protection unit is eliminated, thereby ensuring its safety in use.

[0048] Optionally, in this embodiment, the energy storage unit is a lithium battery, the preset temperature is about 90°C, and the upper safety limit temperature is in the range of 200°C-300°C. Optionally, the material of the pressure relief core 12 is POM (Polyoxymethylene), and its melting point is in the range of 200°C-300°C.

[0049] Optionally, a groove 121 is provided at one end of the pressure relief core 12 close to the medicine chamber 21, and the groove 121 extends along the axial depth of the pressure relief core 12. Providing the groove 121 can reduce the thickness of the pressure relief core 12, and the bottom of the groove 121 faces the outside of the shell 2. The thickness of the bottom of the groove is reduced, which can ensure the speed of melting through the pressure relief core 12, and the melting speed will not be too slow due to excessive thickness.

[0050] Optionally, the end of the pressure relief core 12 away from the medicine chamber 21 has a curved surface protruding structure 122, and the curved surface protruding structure 122 protrudes in the direction away from the medicine chamber 21 to increase the pressure bearing capacity here and prevent a certain part of the end from being subjected to excessive force. Optionally, the curved surface protruding structure 122 is located on the side of the groove bottom of the groove 121 facing the outside of the shell 2, and the curved surface protruding structure 122 can be a spherical structure.

[0051] In order to prevent gas leakage from the pressure relief device 1 during the normal spraying of the medicine from the medicine chamber 21, the pressure relief device 1 optionally further includes a first sealing ring 13 to block the gap between the pressure relief seat 11 and the shell 2 to ensure sealing. The pressure relief seat 11 includes a main body 111 and a pressing protrusion 112. The first sealing ring 13 is sleeved on the main body 111. The main body 111 is partially inserted into the assembly hole. The diameter of the pressing protrusion 112 is larger than the inner diameter of the assembly hole. The first sealing ring 13 is pressed between the pressing protrusion 112 and the shell 2. Optionally, an external thread 1111 is provided on the outer wall of the main body 111, and the assembly hole is a threaded hole. The main body 111 is threadedly connected to the shell 2. As the main body 111 is extended into the assembly hole, the first sealing ring 13 can be pressed. Optionally, the pressing protrusion 112 is located on the outside of the shell 2 for easy assembly.

[0052] Optionally, the pressure relief device 1 further includes a second sealing ring 14, which is sleeved on the pressure relief core 12. The second sealing ring 14 is used to form a circumferential seal between the pressure relief core 12 and the inner wall of the through hole to prevent gas from leaking from between the pressure relief core 12 and the inner wall of the through hole. Optionally, a plurality of second sealing rings 14 are provided, and two are provided in this embodiment to further ensure the sealing performance. Optionally, a positioning groove is provided on the outer wall of the pressure relief core 12 or the inner wall of the through hole, and the second sealing ring 14 is located in the positioning groove to prevent the second sealing ring 14 from moving.

[0053] Optionally, the first sealing ring 13 is a combined sealing gasket with a certain thickness. The inner ring of the combined sealing gasket is made of rubber material, and the outer ring is made of metal material, that is, the metal ring wraps the rubber ring to ensure that the rubber ring of the inner ring can fit the main body 111, and the metal ring of the outer ring can ensure its structural strength and will not break or fail.

[0054] In order to prevent the pressure relief core 12 from moving along the axial direction of the through hole, optionally, a first limiting protrusion 113 is provided around the inner wall of the through hole, and the pressure relief core 12 is closer to the medicine chamber 21 than the first limiting protrusion 113, and the first limiting protrusion 113 can prevent the pressure relief core 12 from moving outward under the action of air pressure. Optionally, a second limiting protrusion (not shown in the figure) is provided around the inner wall of the through hole, and the pressure relief core 12 is farther away from the medicine chamber 21 than the second limiting protrusion, and the second limiting protrusion can prevent the pressure relief core 12 from moving into the shell 2.

[0055] Optionally, the pressure relief seat 11 is made of stainless steel to facilitate heat transfer to the pressure relief core 12, ensuring that the temperature of the pressure relief core 12 changes rapidly with the external temperature to avoid delays and dangers.

[0056] like Figure 4-Figure 7 As shown, this embodiment also provides a thermal runaway prevention unit, comprising a housing 2 and the above-mentioned pressure relief device 1. The thermal runaway prevention unit can prevent explosion in a high temperature environment and ensure its safety in use.

[0057] Optionally, the thermal runaway prevention unit further includes an injection valve (not shown in the figure), which is arranged at the injection port of the housing 2, and the injection port is connected to the agent chamber 21. The housing 2 also has a driving gas chamber 22, and the driving gas chamber 22 contains driving gas. The injection pressure of the injection valve is greater than the preset pressure of the agent, and the injection pressure is less than the preset pressure of the driving gas, so that the driving gas can drive the agent to be ejected from the injection valve.

[0058] Optionally, in this embodiment, the driving gas cavity 22 is located in the middle of the shell 2, and the medicine cavity 21 surrounds the driving gas cavity 22. The medicine cavity 21 is an annular cavity, and the medicine cavity 21 is arranged around the driving gas cavity 22. Optionally, the injection port is located at an end of the shell 2 where the pressure relief device 1 is not arranged.

[0059] Optionally, the thermal runaway prevention unit further includes a puncture valve 3, and a blocking piece is provided between the driving gas chamber 22 and the medicine chamber 21. At normal temperature, the blocking piece can ensure that the driving gas chamber 22 and the medicine chamber 21 are separated. Once the injection condition is met, the puncture valve 3 can puncture the blocking piece to connect the driving gas chamber 22 with the medicine chamber 21, and the driving gas can drive the medicine to be ejected from the injection valve.

[0060] Optionally, the puncture valve 3 is located at one end of the housing 2 where the pressure relief device 1 is provided. That is, once the injection condition is reached, the puncture valve 3 can puncture the blocking member, and the driving gas enters the medicine chamber 21 from one end of the housing 2, the air pressure in the medicine chamber 21 increases, and the medicine is ejected from the injection valve at the other end of the housing 2 under the drive of the driving gas. Optionally, the puncture valve 3 is an electric explosion valve so that it can be electrically controlled to ensure the response speed. Since the electric explosion valve is a prior art, its working principle is not described in detail here.

[0061] Optionally, the housing 2 is provided with one end of the puncture valve 3, and a first passage and a second passage are provided inside. One end of the first passage is connected to the side opening of the puncture valve 3, and the other end is connected to the medicine chamber 21. One end of the second passage is connected to the bottom opening of the puncture valve 3, and the other end is connected to the driving gas chamber 22, and a blocking member is provided in the second passage. Once the blocking member is punctured, the driving gas can enter the medicine chamber 21 through the second passage and the first passage in sequence.

[0062] Optionally, a third passage 23 is further provided at the end of the housing 2, one end of the third passage 23 is connected to the medicine chamber 21, and the other end is connected to the medicine filling port. The through hole of the pressure relief device 1 is connected to the third passage 23, and thus connected to the medicine chamber 21.

[0063] Optionally, in this embodiment, the agent is perfluorohexanone, and the driving gas is high-pressure nitrogen, which also has a flame retardant effect.

[0064] Before thermal runaway occurs, the pressure relief device 1 has a blocking effect, sealing the agent in the agent chamber 21. After thermal runaway occurs, the puncture valve 3 punctures the blocking piece, and the agent is ejected under the drive of the driving gas. At this time, the agent chamber 21 is still connected to the pressure relief device 1 from the inside of the shell 2, and the ejection of the agent will also reduce the temperature near the pressure relief device 1 outside the shell 2, so the pressure relief core 12 will not melt. Until the spraying of the agent is completed, due to the provision of an injection valve, after the agent gas is sprayed, there will still be a pressure of about 2MPa in the agent chamber 21 and the driving gas chamber 22. Once the thermal runaway is not controlled, the ambient temperature near the pressure relief device 1 will also rise sharply. When it rises to the range of 200℃-300℃, the pressure relief core 12 melts, and the agent chamber 21 and the driving gas chamber 22 are connected to the outside world, releasing the remaining 2MPa gas in the agent chamber 21 and the driving gas chamber 22.

[0065] This embodiment also provides an energy storage system, including an energy storage unit, a control unit, a detection unit and the above-mentioned thermal runaway prevention unit. The detection unit includes a temperature sensor, which is used to detect the temperature of the energy storage unit. The control unit is communicatively connected with the temperature sensor and the puncture valve 3 of the thermal runaway prevention unit, and the control unit can control the action of the puncture valve 3 according to the detection result of the temperature sensor.

[0066] Optionally, the energy storage system can be equipped with one thermal runaway prevention unit, or multiple thermal runaway prevention units can be equipped according to the number of battery modules included, which can be selected according to the specifications of the energy storage system. If multiple thermal runaway prevention units are used, it is necessary to ensure that the injection ports of the multiple thermal runaway prevention units are respectively facing the multiple battery modules to ensure their cooling and flame retardant effects.

[0067] Optionally, in this embodiment, the energy storage system is a battery system, and the control unit is a battery management unit. Since battery management units are relatively common, they are not described here in detail.

[0068] This embodiment also provides a control method, which is applied to the above energy storage system. The control method includes the following steps:

[0069] First, determine whether the temperature of the energy storage unit reaches the preset temperature, that is, whether it reaches 90°C. If so, it is considered that the energy storage unit has the possibility of heating up and burning. The control unit sends an action signal to the puncture valve 3 to control the puncture valve 3 to puncture the blocking member, so that the agent chamber 21 and the driving gas chamber 22 of the anti-thermal runaway unit are connected, and the driving gas drives the agent to spray into the energy storage unit to cool down or flame retard the energy storage unit. The temperature here can be the average temperature of each battery module or battery cell, or it can be the temperature of a battery module or a battery cell. In fact, when the temperature of a battery cell is too high, it is necessary to perform safety treatments such as cooling or flame retardancy to prevent the spread of thermal runaway.

[0070] If the thermal runaway is not controlled and the temperature of the energy storage unit rises further, it is necessary to release the pressure in the agent chamber 21 and the driving gas chamber 22 to prevent the explosion of the thermal runaway protection unit. When the temperature at the thermal runaway protection unit is higher than the melting temperature of the pressure relief core 12, that is, the temperature rises to the range of 200°C-300°C, the pressure relief core 12 melts, and the gas in the thermal runaway protection unit is released from the through hole of the pressure relief seat 11 to the outside of the shell 2, and the pressure in the agent chamber 21 and the driving gas chamber 22 is completely released, eliminating the risk of explosion.

[0071] The energy storage system mentioned above uses the control method to prevent the explosion of the thermal runaway prevention unit in a high temperature environment, thereby ensuring the safety of the use of the thermal runaway prevention unit.

[0072] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A pressure relief device (1), characterized in that: Used to ensure the safety of use of a thermal runaway prevention unit, the thermal runaway prevention unit comprising a housing (2), the housing (2) having a medicine chamber (21), when the energy storage unit reaches a preset temperature, the medicine in the medicine chamber (21) is sprayed toward the energy storage unit, and the pressure relief device (1) comprises: A pressure relief seat (11), the pressure relief seat (11) being inserted into the assembly hole of the shell (2), a through hole being formed in the pressure relief seat (11), one end of the through hole being connected to the medicine chamber (21), and the other end of the through hole being connected to the outside of the shell (2); A pressure relief core (12), the pressure relief core (12) being arranged in the through hole to block the through hole, the melting temperature of the pressure relief core (12) being higher than the preset temperature, and the melting temperature being lower than the upper safety limit temperature after thermal runaway of the energy storage unit; Before the medicine is sprayed out, the pressure relief core (12) will not melt, so that the medicine can be prevented from spraying out from the pressure relief device (1), but accurately sprayed out from the spray port toward the energy storage unit; after the medicine is sprayed out, if the temperature of the energy storage unit continues to rise, when the temperature rise does not reach the safety upper limit temperature, the pressure relief core (12) will melt, causing the medicine chamber (21) to communicate with the outside of the shell (2), and the remaining gas is released to the outside of the shell (2).

2. The pressure relief device (1) according to claim 1, characterized in that: A groove (121) is provided at one end of the pressure relief core (12) close to the medicine chamber (21), and the groove (121) extends along the axial depth of the pressure relief core (12).

3. The pressure relief device (1) according to claim 1, characterized in that: One end of the pressure relief core (12) that faces away from the medicine chamber (21) has a curved surface protruding structure (122), and the curved surface protruding structure (122) protrudes in a direction away from the medicine chamber (21).

4. The pressure relief device (1) according to claim 1, characterized in that: The pressure relief device (1) further comprises a first sealing ring (13); the pressure relief seat (11) comprises a main body (111) and a pressing protrusion (112); the first sealing ring (13) is sleeved on the main body (111); a portion of the main body (111) is inserted into the assembly hole; the diameter of the pressing protrusion (112) is greater than the inner diameter of the assembly hole; the first sealing ring (13) is pressed between the pressing protrusion (112) and the housing (2); And / or, the pressure relief device (1) further comprises a second sealing ring (14), the second sealing ring (14) being sleeved on the pressure relief core (12), the second sealing ring (14) being used to form a circumferential seal between the pressure relief core (12) and the inner wall of the through hole.

5. The pressure relief device (1) according to claim 1, characterized in that: The inner wall of the through hole is provided with a first limiting protrusion (113), and the pressure relief core (12) is closer to the medicine chamber (21) than the first limiting protrusion (113); And / or, a second limiting protrusion is provided around the inner wall of the through hole, and the pressure relief core (12) is farther away from the medicine chamber (21) than the second limiting protrusion.

6. Thermal runaway prevention unit, characterized in that: It comprises a housing (2) and a pressure relief device (1) as claimed in any one of claims 1 to 5.

7. The thermal runaway prevention unit according to claim 6, characterized in that: The thermal runaway prevention unit further comprises an injection valve, the injection valve being arranged at an injection port of the shell (2), the shell (2) further comprising a driving gas chamber (22), the driving gas chamber (22) containing a driving gas, the injection pressure of the injection valve being greater than a preset pressure of the agent, and the injection pressure being less than a preset pressure of the driving gas, so that the driving gas can drive the agent to be ejected from the injection valve.

8. The thermal runaway prevention unit according to claim 7, characterized in that: The thermal runaway prevention unit further comprises a puncture valve (3), a blocking piece is provided between the driving gas chamber (22) and the medicine chamber (21), and the puncture valve (3) is capable of puncturing the blocking piece to allow the driving gas chamber (22) to communicate with the medicine chamber (21).

9. An energy storage system, characterized in that: It comprises an energy storage unit, a control unit, a detection unit and the thermal runaway protection unit as claimed in any one of claims 6 to 8, wherein the detection unit comprises a temperature sensor, and the temperature sensor is used to detect the temperature of the energy storage unit. The control unit is communicatively connected with the temperature sensor and the puncture valve (3) of the thermal runaway protection unit, and the control unit can control the action of the puncture valve (3) according to the detection result of the temperature sensor.

10. A control method, characterized in that: Applied to the energy storage system as claimed in claim 9, the control method comprises the following steps: It is determined whether the temperature of the energy storage unit reaches a preset temperature. If so, the control unit controls the puncture valve (3) to puncture the blocking member so that the driving gas driving agent of the thermal runaway prevention unit is ejected toward the energy storage unit. When the temperature at the thermal runaway prevention unit is higher than the melting temperature of the pressure relief core (12), the pressure relief core (12) melts, and the gas in the thermal runaway prevention unit is completely released.

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