Fire prevention device for battery system, battery system and fire prevention method

Abstract

The application relates to a fireproof device for a battery system, the battery system and a fireproof method, wherein the battery system comprises a battery pack and a battery management system, the fireproof device comprises: a temperature detection unit comprising a plurality of temperature detection switches arranged in the battery pack; an always-open valve arranged on a liquid cooling pipeline of the battery pack and used for being closed to block the flow of cooling liquid in the liquid cooling pipeline according to a first power-on signal issued by the battery management system when the current temperature of the battery pack exceeds a preset combustion temperature threshold; and at least one always-closed valve arranged at the gap between two adjacent rows of battery cells of the battery pack and used for being opened to make the cooling liquid in the liquid cooling pipeline spray according to a second power-on signal issued by the battery management system when the current temperature of the battery pack exceeds the preset combustion temperature threshold. The application can solve the problem that it is difficult to extinguish the fire at the initial stage of the battery pack, reduce the loss of passengers and vehicles, and further improve the safety of the battery system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a fireproof device for a battery system, a battery system and a fireproof method. BACKGROUND

[0002] At present, when a fire occurs in an electric vehicle, multiple fire extinguishers or a large amount of water are often used to extinguish the fire, which consumes a long time and causes the vehicle to be severely damaged even if the fire is extinguished.

[0003] The above phenomenon is related to the mechanism of the fire of the electric vehicle. Since the electric vehicle is in thermal runaway or impact fire, the flame usually first burns from the battery cell inside the battery pack, and the ignition point is separated from the fire extinguisher (or fire hose) by the battery box and the vehicle shell, so that the outside can only see smoke but not fire, which makes it difficult for the dry powder or water source to reach the battery cell ignition point and difficult to extinguish the fire at the moment of the battery cell fire.

[0004] In addition, many electric vehicles driving on the highway usually do not have fire extinguishers or water, and can only burn the electric vehicle before waiting for the arrival of the fire department, which is easy to cause irreparable loss to the passengers and the vehicle. SUMMARY

[0005] Therefore, the present application provides a fireproof device for a battery system, a battery system and a fireproof method, which can solve the problem of difficulty in extinguishing the fire at the initial stage of the fire of the battery pack and reduce the loss of passengers and vehicles. The liquid cooling system is used to automatically extinguish the fire from the inside at the initial stage of the fire of the battery pack, which avoids the situation that the unprofessional passengers extinguish the fire themselves and cause burns, and further improves the safety of the battery system.

[0006] In a first aspect, embodiments of the present application provide a fireproof device for a battery system, the battery system comprising a battery pack, a battery management system electrically connected with the battery pack, the fireproof device comprising: a temperature detection unit electrically connected with the battery management system, the temperature detection unit comprising a plurality of temperature detection switches arranged inside the battery pack, the plurality of temperature detection switches configured to detect a current temperature of the battery pack; a normally open valve electrically connected with the battery management system, the normally open valve arranged on a liquid cooling pipeline of the battery pack, the liquid cooling pipeline comprising a water inlet and a water outlet, the normally open valve configured to be closed according to a first energization signal issued by the battery management system in a case where the current temperature of the battery pack exceeds a preset combustion temperature threshold, so as to block the flow of cooling liquid in the liquid cooling pipeline; and at least one normally closed valve electrically connected with the battery management system and mechanically connected with the liquid cooling pipeline, the normally closed valve arranged inside the battery pack and located between the water inlet and the normally open valve, the normally closed valve configured to be opened according to a second energization signal issued by the battery management system in a case where the current temperature of the battery pack exceeds the preset combustion temperature threshold, so as to cause the cooling liquid in the liquid cooling pipeline to spray the battery cells inside the battery pack.

[0007] In an embodiment, the normally open valve comprises a first liquid flow channel and a first magnetic valve assembly, the first liquid flow channel being in communication with the liquid cooling pipeline, and the first magnetic valve assembly comprising a first coil and a first magnetic valve, the first magnetic valve being located in a magnetic field generated by the energization of the first coil to close the first liquid flow channel.

[0008] In an embodiment, the normally open valve further comprises a first housing, the first liquid flow channel and the first magnetic valve assembly being arranged inside the first housing, the first coil being sleeved on a top portion of the first housing, and the first coil being configured to generate a first magnetic force after being energized.

[0009] In an embodiment, the first magnetic valve comprises a first magnet and a first valve core, the first magnet being in contact with the first valve core, the first coil being sleeved on at least a portion of an outer wall of the first magnet, and the first magnetic valve being configured such that the first magnet moves in a direction away from the first coil under the action of the first magnetic force, and the first magnet pushes the first valve core to move in a direction away from the first coil and close the first liquid passage.

[0010] In an embodiment, the first spool is provided with a first spool channel, and the normally open valve is configured to, in the first coil de-energized state, the first spool channel is in communication with the first liquid flow channel; in the first coil energized state, the first magnet moves in a direction away from the first coil under the action of the first magnetic force, and the first magnet pushes the first spool to move in a direction away from the first coil, and the first spool channel is misaligned with the first liquid flow channel, so that the first liquid channel is closed.

[0011] In an embodiment, the first magnet comprises a first part and a second part, and the outer diameter of the first part is smaller than the outer diameter of the second part, and the first coil is sleeved on the outer sidewall of the first part, and the second part is in contact with the first spool away from the end face of the first part.

[0012] In an embodiment, the normally open valve further comprises a first water nozzle and a second water nozzle, the first water nozzle, the first liquid channel and the second water nozzle are in communication, and the first water nozzle and the second water nozzle are respectively arranged on both sides of the first spool and are in butt joint with the liquid cooling pipeline through the first shell.

[0013] In an embodiment, the normally open valve further comprises a first elastic member, the first elastic member is in contact with one end of the first spool away from the first magnet, and the first elastic member is configured to, in the first coil de-energized state, push the first spool to move in a direction close to the first coil until the first spool channel is in communication with the first liquid flow channel.

[0014] In an embodiment, the first elastic member is a first spring, and the first spring is spirally arranged around the inner wall of the first shell.

[0015] In an embodiment, the normally open valve further comprises a first limiting part, the first limiting part is arranged on the inner sidewall of the first shell and protrudes in a direction away from the outer sidewall of the first shell.

[0016] In an embodiment, the normally open valve is arranged adjacent to the water outlet of the liquid cooling pipeline.

[0017] In an embodiment, the first magnet is in a T-shaped structure.

[0018] In an embodiment, the normally closed valve is internally provided with a second liquid flow channel and a second magnetic force valve assembly, the second magnetic force valve assembly comprises a second coil and a second magnetic force valve, and the second magnetic force valve is located in the magnetic field generated by the energized second coil to make the second liquid flow channel in communication with the liquid cooling pipeline.

[0019] In an embodiment, the normally closed valve further comprises a second housing, the second liquid flow channel and the second magnetic valve assembly are arranged inside the second housing, the second coil is arranged on the top of the second housing, and the second coil is arranged to generate a second magnetic force when energized.

[0020] In an embodiment, the second magnetic valve comprises a second magnet and a second valve core, the second magnet is in contact with the second valve core, the second coil is arranged on at least part of the outer wall of the second magnet, and the second magnetic valve is arranged such that the second magnet moves away from the second coil under the action of the second magnetic force, and the second magnet pushes the second valve core to move away from the second coil, so that the second liquid passage is in communication with the liquid cooling pipeline.

[0021] In an embodiment, the second valve core is provided with a second valve core passage, and the normally closed valve is arranged such that, in the second coil de-energized state, the second valve core passage is disconnected from the second liquid flow channel; in the second coil energized state, the second magnet moves away from the second coil under the action of the second magnetic force, and the second magnet pushes the second valve core to move away from the second coil, and the second valve core passage is in communication with the second liquid flow channel, so that the second liquid passage is opened.

[0022] In an embodiment, the second magnet comprises a third part and a fourth part, and the outer diameter of the third part is smaller than the outer diameter of the fourth part, the second coil is arranged on the outer wall of the third part, and the fourth part is in contact with the second valve core away from the end face of the third part.

[0023] In an embodiment, the normally closed valve further comprises a third water nozzle, the third water nozzle is arranged on one side of the second valve core and penetrates through the second housing to be connected with the liquid cooling pipeline.

[0024] In an embodiment, the normally closed valve further comprises a second elastic member, the second elastic member is in contact with one end of the second valve core away from the second magnet, and the second elastic member is arranged to push the second valve core to move away from the second coil until the second valve core opens the second liquid flow channel in the second coil energized state, and to push the second valve core to move close to the second coil until the second valve core closes the second liquid flow channel after the second coil is de-energized.

[0025] In an embodiment, the second elastic member is a second spring, and the second spring is arranged in a spiral around the inner wall of the second housing.

[0026] In an embodiment, the normally closed valve further comprises a second limiting portion, which is arranged on the inner side wall of the second shell and protrudes away from the outer side wall of the second shell.

[0027] In an embodiment, the battery pack comprises a plurality of cell modules, each of which is connected to each other, and the normally closed valve is arranged in the gap between two adjacent cell modules along the direction in which the liquid cooling pipeline is arranged.

[0028] In a second aspect, embodiments of the present application provide a battery system, which comprises the fireproof device.

[0029] In a third aspect, embodiments of the present application provide a fireproof method, which comprises: detecting the current temperature of the battery pack; closing the normally open valve to block the flow of the cooling liquid in the liquid cooling pipeline according to the first energizing signal issued by the battery management system when the current temperature of the battery pack exceeds the preset combustion temperature threshold; and opening the normally closed valve to spray the cooling liquid in the liquid cooling pipeline to the cells in the battery pack according to the second energizing signal issued by the battery management system when the current temperature of the battery pack exceeds the preset combustion temperature threshold.

[0030] By arranging the normally open valve and the at least one normally closed valve in the fireproof device, and controlling the on-off of the normally open valve and the at least one normally closed valve by the battery management system, the normally open valve can be opened to block the flow of the cooling liquid in the liquid cooling pipeline and the at least one normally closed valve can be opened to spray the cooling liquid in the liquid cooling pipeline to extinguish the fire when the current temperature of the battery pack exceeds the preset combustion temperature threshold, so that the problem of difficulty in extinguishing the fire at the initial stage of the fire of the battery pack can be solved according to the aspects of the present application, and the loss of the occupants and the vehicle can be reduced. In addition, the liquid cooling system is used to automatically extinguish the fire from the inside at the initial stage of the fire of the battery pack, so that the situation of burns of the occupants caused by the unprofessional occupants extinguishing the fire themselves can be avoided, and the safety of the battery system is further improved. BRIEF DESCRIPTION OF DRAWINGS

[0031] The technical solutions and other beneficial effects of the present application will become apparent from the following detailed description of specific embodiments of the present application, combined with the accompanying drawings.

[0032] Figure 1 An explosion schematic diagram of the fireproof device for the battery system according to an embodiment of the present application is shown.

[0033] Figure 2 A three-dimensional structure schematic diagram of the liquid cooling plate according to an embodiment of the present application is shown.

[0034] Figure 3 A planar structure schematic diagram of the liquid cooling plate according to an embodiment of the present application is shown.

[0035] Figure 4 A perspective structural schematic diagram of the normally open valve according to the embodiment of the present application is shown.

[0036] Figure 5 A cross-sectional structural schematic diagram of the normally open valve according to the embodiment of the present application is shown.

[0037] Figure 6 A perspective structural schematic diagram of the normally closed valve according to the embodiment of the present application is shown.

[0038] Figure 7 A cross-sectional structural schematic diagram of the normally closed valve according to the embodiment of the present application is shown.

[0039] Figure 8 A working schematic diagram of the fireproof device according to the embodiment of the present application is shown. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0041] In the description of the present application, it should be understood that the terms “center”, “longitudinal”, “transverse”, “length”, “width”, “thickness”, “upper”, “lower”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer”, “clockwise”, “counterclockwise” and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms “first” and “second” are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by “first” and “second” can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of “multiple” is two or more, unless otherwise specifically limited.

[0042] In the description of the application, it is necessary to point out that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection or can communicate with each other; it can be direct connection, or indirect connection through intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0043] The following disclosure provides many different embodiments or examples for implementing different structures of the application. In order to simplify the disclosure of the application, the components and arrangements of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the application. In addition, reference numerals and / or reference letters can be repeated in different examples in the application, and such repetition is for the purpose of simplification and clarity, and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, the application provides examples of various specific processes and materials, but those skilled in the art can realize the application of other processes and / or the use of other materials. In some examples, methods, means, elements and circuits well known to those skilled in the art are not described in detail in order to highlight the main ideas of the application.

[0044] Figure 1 The explosion schematic diagram of the fireproof device for the battery system is shown. The fireproof device can be applied to the battery system. The battery system can include a battery pack, a battery management system (BMS) electrically connected with the battery pack, and a fireproof device electrically connected with the battery management system. In the application, the fireproof device can be arranged in the battery system as part of the battery system.

[0045] Referring to Figure 1 The battery pack provided by the embodiments of the application can include a box body 1 and a plurality of battery modules 3. The box body 1 can be used to carry a plurality of battery modules 3. The battery module 3 includes a plurality of battery cells and a liquid cooling assembly 2. The liquid cooling assembly 2 can be arranged in a serpentine flat tube, and the serpentine flat tube can be arranged in the gap between the battery cells in each battery module 3. The liquid cooling assembly 2 can also be arranged as a liquid cooling plate, and the liquid cooling plate is in thermal conductive connection with the end surface of the battery cell.

[0046] Each battery module 3 can include a plurality of battery cells 30, and the plurality of battery cells can be arranged in a row-column form to form a plurality of rows of battery cells. For example, in the example shown in the figure, each battery module 3 can include a plurality of rows of battery cells arranged in a row-column form. Figure 1The battery pack is provided with three battery modules, each of which includes a same number of rows of battery cells 30. The battery cells 30 can be cylindrical.

[0047] In an embodiment, the fireproof device can include a temperature detection unit electrically connected with the battery management system. The temperature detection unit can include a plurality of temperature detection switches arranged inside the battery pack, for detecting a current temperature of the battery pack. The temperature detection switches can be Negative Temperature Coefficient (NTC) temperature sensors, which can exponentially decrease in resistance as temperature rises. It can be understood that the positions and number of the temperature detection switches can be adjusted as needed, and the present application is not limited in this regard.

[0048] Figure 2 A perspective structural schematic diagram of the liquid cooling plate of the embodiment of the present application is shown. As shown, Figure 2 According to the modular division of the battery cells, the liquid cooling plate can also be divided into liquid cooling modules 21, 22 and 23. Each liquid cooling module can include a plurality of liquid cooling sub-plates 20. For example, the liquid cooling sub-plates 20 can be wave-shaped. Of course, the number of liquid cooling sub-plates in each liquid cooling module can be the same or different. It can be understood that the present application does not limit how the liquid cooling modules are divided.

[0049] Further, the fireproof device can include a normally open valve 41 and at least one normally closed valve 42. For example, in Figure 2 The gap of the liquid cooling plate can be provided with one normally open valve 41 and four normally closed valves 42. The normally open valve 41 can be located at a corner of the liquid cooling module 21, and the four normally closed valves can be arranged in the gaps between the liquid cooling module 21 and the liquid cooling module 22 and between the liquid cooling module 22 and the liquid cooling module 23.

[0050] In an embodiment, the normally open valve is electrically connected with the battery management system. The normally open valve is arranged on a liquid cooling pipeline of the battery pack, the liquid cooling pipeline including a water inlet and a water outlet, and the normally open valve is arranged to be closed according to a first power-on signal issued by the battery management system in a case where the current temperature of the battery pack exceeds a preset combustion temperature threshold, so as to block the flow of the cooling liquid in the liquid cooling pipeline.

[0051] In an embodiment, each normally closed valve can be electrically connected with the battery management system, and each normally closed valve can be mechanically connected with the liquid cooling pipe. The normally closed valve is arranged inside the battery pack and between the water inlet and the normally open valve. Further, the normally closed valve is arranged at the gap between two adjacent rows of battery cells of the battery pack. The normally closed valve is arranged to be opened according to the second energization signal sent by the battery management system when the current temperature of the battery pack exceeds the preset combustion temperature threshold, so as to spray the cooling liquid in the liquid cooling pipe to the battery cells in the battery pack.

[0052] In an embodiment, the battery management system can receive the current temperature sent by the temperature detection unit, and then compare the current temperature with the preset combustion temperature threshold. When the current temperature exceeds the preset combustion temperature threshold, it indicates that the temperature of the battery pack is too high, and the battery pack has a risk of combustion. At this time, the battery management system can send a first energization signal to the normally open valve to energize the normally open valve to be closed, and send a second energization signal to the normally closed valve to energize the normally closed valve to be opened. When the current temperature does not exceed the preset combustion temperature threshold, it indicates that the temperature of the battery pack is appropriate, and the battery pack does not have a risk of combustion. At this time, the battery management system can control the normally open valve and the normally closed valve to remain in a de-energized state.

[0053] It should be noted that the normally open valve and the normally closed valve can be energized at the same time or in a sequence. The application does not limit the energization sequence of the normally open valve and the normally closed valve.

[0054] Figure 3 A planar structure schematic diagram of the liquid cooling plate of the embodiment of the application is shown. As shown in Figure 3 The two sides of the liquid cooling plate 2 can be provided with a first liquid cooling pipe 241 and a second liquid cooling pipe 242. The first liquid cooling pipe 241 is connected with the corresponding liquid cooling sub-plate through a plurality of first connecting portions, and the second liquid cooling pipe 242 is connected with the corresponding liquid cooling sub-plate through a plurality of second connecting portions.

[0055] In an embodiment, the normally open valve is arranged adjacent to the water outlet of the liquid cooling pipe. For example, the first liquid cooling pipe 241 can be provided with a water outlet 2411, and the normally open valve 41 can be arranged adjacent to the water outlet 2411 of the first liquid cooling pipe 241, so that the normally open valve 41 can timely block the flow of the cooling liquid in the liquid cooling pipe when energized.

[0056] In an embodiment, the normally closed valve is arranged in the gap between two adjacent battery modules along the arrangement direction of the liquid cooling pipe. The gap between the two adjacent battery modules along the arrangement direction of the liquid cooling pipe is a first gap, and the normally closed valve is arranged in the first gap. For example, in Figure 3In the middle, two first gaps are formed between the three battery modules, and two normally closed valves can be arranged in each first gap. Notably, Figure 3 The normally closed valves in the middle can be connected to the first liquid cooling pipe or the second liquid cooling pipe through a pipeline, and the adjacent two normally closed valves in the same first gap can also be connected through a pipeline.

[0057] In an embodiment, in the battery module, the gap between the two adjacent rows of battery cells along the direction in which the liquid cooling pipe is arranged is a second gap, and the width of the second gap is smaller than the width of the first gap. A plurality of liquid cooling sub-plates can be respectively arranged in each second gap.

[0058] Figure 4 A perspective view of the normally open valve according to an embodiment of the application is shown. Referring to Figure 4 , the normally open valve 41 can be arranged on the first liquid cooling pipe 241, and the first liquid cooling pipe 241 includes a first liquid cooling sub-pipe 411 and a first liquid cooling sub-pipe 412, which can be arranged on the two sides of the normally open valve 41. On the top of the normally open valve 41, a positive electrode control wire 4101 and a negative electrode control wire 4102 can be arranged. The normally open valve 41 can be electrically connected to the battery management system of the battery system through the positive electrode control wire 4101 and the negative electrode control wire 4102, and the positive electrode control wire 4101 and the negative electrode control wire 4102 can be used to transmit a first power-on signal from the battery management system.

[0059] Referring to Figure 4 , the normally open valve 41 can include a first housing 410. The first housing 410 can have a square structure. Two small holes can be formed on the top of the first housing 410 for accommodating the positive electrode control wire 4101 and the negative electrode control wire 4102 to pass into the cavity inside the first housing 410. Two openings are arranged on the two sides of the first housing 410 for accommodating the first liquid cooling sub-pipe 411 and the first liquid cooling sub-pipe 412 to pass into the cavity inside the first housing 410.

[0060] Figure 5 A cross-sectional view of the normally open valve according to an embodiment of the application is shown. As Figure 5 shown, the normally open valve 41 is cut in half from the middle to obtain Figure 5 a cross-sectional view.

[0061] In an embodiment, the normally open valve 41 overlaps the liquid cooling pipe to form a flow channel, so that the cooling liquid can circulate normally under non-fire conditions. Specifically, referring to Figure 5The normally open valve is internally provided with a first liquid flow channel 417 and a first magnetic valve assembly. The first liquid flow channel 417 is in communication with the liquid cooling pipe. The first magnetic valve assembly includes a first coil 413 and a first magnetic valve. The first magnetic valve is located in the magnetic field generated by the energized first coil to close the first liquid flow channel.

[0062] In an embodiment, the first coil 413 is arranged around the inner wall of the first housing 410. The first coil 413 is used to generate a first magnetic force after the normally open valve is energized. The first coil 413 can be circular, elliptical, rectangular, or other shapes. For example, the cross section of the first coil can be U-shaped. Figure 5 The first coil 413 is electrically connected to the positive control wire 4101 and the negative control wire 4102.

[0063] In an embodiment, referring to Figure 5 The first magnetic valve includes a first magnet 414 and a first valve core 415. The first magnet is in contact with the first valve core. The first coil is sleeved on at least part of the outer wall of the first magnet. The first magnetic valve is arranged such that the first magnet moves in a direction away from the first coil under the action of the first magnetic force, and the first magnet pushes the first valve core to move in a direction away from the first coil and close the first liquid channel. The first valve core 415 can be arranged on one side of the first magnet. The first valve core 415 is used to move in a direction away from the first coil under the action of the first magnet.

[0064] In an embodiment, referring to Figure 5 The first magnet 414 is arranged on one side of the first coil. The shape of the first magnet 414 can be T-shaped structure. For example, the polarity of the side of the first magnet close to the first coil is the same as the polarity of the first magnetic force. In Figure 5 The horizontal part of the T-shaped structure can be used to interact with the first coil, and the vertical part of the T-shaped structure can be used to support the first coil.

[0065] In an embodiment, the first liquid flow channel and the first magnetic valve assembly are arranged inside the first housing. The first coil is sleeved on the top of the first housing. The first coil is arranged to generate a first magnetic force after being energized.

[0066] In an embodiment, the first spool 415 is provided with a first spool passage, and the normally open valve is configured to communicate the first spool passage with the first liquid flow passage in the first coil de-energized state, and to misalign the first spool passage with the first liquid flow passage in the first coil energized state, so as to close the first liquid passage.

[0067] In an embodiment, the first magnet comprises a first portion and a second portion, and the first portion has an outer diameter smaller than that of the second portion, and the first coil is sleeved on the outer sidewall of the first portion, and the second portion is in contact with the first spool away from the end surface of the first portion.

[0068] In an embodiment, referring to Figure 5 , the normally open valve further comprises a first water nozzle 4110 and a second water nozzle 4120, the first water nozzle, the first liquid passage and the second water nozzle are in communication, and the first water nozzle and the second water nozzle are respectively arranged on two sides of the first spool and are respectively connected to the liquid cooling pipeline through the first shell. The first water nozzle 4110 can be connected to the first liquid cooling sub-pipeline 411, and the second water nozzle 4120 can be connected to the first liquid cooling sub-pipeline 412. When the first coil is energized, the first magnet can move downward to push the first spool in contact with the first magnet to also move downward, so that the cooling liquid of the first water nozzle 4110 and the second water nozzle 4120 is blocked, thereby terminating the entire liquid cooling cycle.

[0069] In an embodiment, the normally open valve further comprises a first elastic member, the first elastic member is in contact with one end of the first spool away from the first magnet, and the first elastic member is configured to push the first spool to move in the direction close to the first coil until the first spool passage communicates with the first liquid flow passage in the first coil de-energized state.

[0070] For example, the first elastic member is a first spring 416, and the first spring 416 is spirally arranged around the inner wall of the first shell. The first spring 416 can be arranged on one side of the first spool to dynamically maintain the position of the first spool. For example, when the first spool 415 is pressed down, the first spring 416 can follow the first spool 415 to press down, so as to maintain the first spool 415 in the pressed-down position.

[0071] In an embodiment, the normally open valve further comprises a first limiting portion, which is arranged on the inner side wall of the first housing and protrudes away from the outer side wall of the first housing. In the first coil de-energized state, the spring moves in the direction close to the first coil until the second part of the first valve core abuts against the first limiting portion.

[0072] Figure 6 A perspective structural schematic diagram of the normally closed valve of the embodiment of the application is shown. Referring to Figure 6 , the normally closed valve 42 can be arranged in the gap between two adjacent battery modules, and the third liquid cooling sub-pipe 421 can be arranged on one side of the normally closed valve 42. On the top of the normally closed valve 42, the positive electrode control wire 4201 and the negative electrode control wire 4202 can be arranged. The normally closed valve 42 can be electrically connected to the battery management system of the battery system through the positive electrode control wire 4201 and the negative electrode control wire 4202, and the positive electrode control wire 4201 and the negative electrode control wire 4202 can be used to transmit the second energizing signal sent by the battery management system.

[0073] Please refer to Figure 6 , the normally closed valve 42 can comprise a second housing 420. The second housing 420 can have a square structure. Two small holes can be formed on the side of the second housing 420 for accommodating the positive electrode control wire 4201 and the negative electrode control wire 4202 to pass into the cavity inside the second housing 420. An opening is arranged on one side of the second housing 420 for accommodating the third liquid cooling sub-pipe 421 to pass into the cavity inside the second housing 420.

[0074] In an embodiment, the normally closed valve 42 can further comprise a spray head 4203 and a bottom disc 4204. The spray head 4203 can be arranged on the top of the normally closed valve 42 for spraying the cooling liquid. The bottom disc 4204 can be arranged on the bottom of the normally closed valve 42 and can be used to support and fix the second housing 420.

[0075] Figure 7 A cross-sectional structural schematic diagram of the normally closed valve of the embodiment of the application is shown. As Figure 7 , the normally closed valve 42 is cut in half from the middle to obtain Figure 7 , a cross-sectional structural schematic diagram.

[0076] Referring to Figure 7 , the normally closed valve is internally provided with a second liquid flow channel 426 and a second magnetic force valve assembly, the second magnetic force valve assembly comprises a second coil 422 and a second magnetic force valve, and the second magnetic force valve is located in the magnetic field generated by the energization of the second coil to make the second liquid flow channel communicate with the liquid cooling pipe.

[0077] In one embodiment, the second coil 422 can be arranged around the inner wall of the second shell 420, and the second coil 422 is used to generate a second magnetic force when the normally closed valve is energized. The second coil 422 can be arranged in a circular, elliptical, rectangular or other shape. For example, in Figure 7 In the embodiment, the cross section of the second coil may also be U-shaped.

[0078] In one embodiment, see Figure 7 The second magnetic valve includes a second magnet 423 and a second valve core 424. The second magnet contacts the second valve core, and the second coil is sleeved around at least a portion of the outer wall of the second magnet. The second magnetic valve is configured such that the second magnet moves away from the second coil under the influence of the second magnetic force, and the second magnet pushes the second valve core to move away from the second coil, thereby connecting the second liquid channel to the liquid cooling pipe. The second valve core 424 can be disposed on one side of the second magnet and is configured to move away from the second coil under the push of the second magnet.

[0079] In one embodiment, see Figure 7 , the second magnet 423 is arranged on one side of the first coil, and the shape of the second magnet 423 can be a T-shaped structure. Exemplarily, the polarity of the second magnet close to the second coil is the same as the polarity of the second magnetic force. Figure 7 In the embodiment, the horizontal portion of the T-shaped structure can be used to interact with the second coil, and the vertical portion of the T-shaped structure can be used to support the second coil.

[0080] In one embodiment, the second liquid flow channel and the second magnetic valve assembly are disposed inside the second shell, the second coil is sleeved on the top of the second shell, and the second coil is configured to generate a second magnetic force when energized.

[0081] In one embodiment, a second valve core channel is provided in the second valve core, and the normally closed valve is configured such that when the second coil is de-energized, the second valve core channel is disconnected from the second liquid flow channel; when the second coil is energized, the second magnet moves in a direction away from the second coil under the action of the second magnetic force, and the second magnet pushes the second valve core to move in a direction away from the second coil, and the second valve core channel is connected to the second liquid flow channel, so that the second liquid channel is opened.

[0082] It should be noted that the second valve core 424 may not be provided with a second valve core channel. In this case, the purpose of opening or closing the second liquid channel can be achieved by controlling whether the second valve core 424 is misaligned with the water nozzle adjacent to the second valve core 424. Figure 7 In some embodiments, the second spool 424 can completely block the adjacent water nozzle, so that the cooling liquid in the water nozzle cannot flow out. When the second spool 424 is misaligned with the water nozzle adjacent to the second spool 424, the cavity above the second spool 424 provides a flow path for the cooling liquid to flow from the water nozzle adjacent to the second spool 424 into the cavity above the second spool 424, and then upsurge to the spray head 4203 to be sprayed out to extinguish the fire.

[0083] In some embodiments, the second magnet includes a third portion and a fourth portion, and the outer diameter of the third portion is smaller than the outer diameter of the fourth portion. The second coil is sleeved on the outer sidewall of the third portion, and the fourth portion is in contact with the second spool away from the end surface of the third portion.

[0084] In some embodiments, the normally closed valve further includes a third water nozzle 4210 disposed on one side of the second spool and penetrating through the second housing to be connected with the liquid cooling pipeline. The third water nozzle 4210 can be connected with a third liquid cooling sub-pipeline 421 connected with the first liquid cooling pipeline 241 or the second liquid cooling pipeline 242. When the second coil is energized, the second magnet can move downward to push the second spool in contact with the second magnet to also move downward, so that the cooling liquid in the third water nozzle 4210 can flow into the cavity of the normally closed valve, and then the cooling liquid flowing into the cavity of the normally closed valve upsurges to the spray head 4203 to be sprayed out to extinguish the fire.

[0085] In some embodiments, the normally closed valve further includes a second elastic member in contact with one end of the second spool away from the second magnet. The second elastic member is configured to, in the energized state of the second coil, push the second spool to move away from the second coil until the second spool opens the second liquid flow channel, and in the de-energized state of the second coil, push the second spool to move close to the second coil until the second spool closes the second liquid flow channel.

[0086] In some embodiments, the second elastic member is a second spring 425 spirally disposed around the inner wall of the second housing, and the second spring is used to dynamically maintain the position of the second spool. For example, when the second spool 424 is pressed down, the second spring 425 can follow the second spool 424 to be pressed down, so that the second spool 424 is maintained in the pressed-down position.

[0087] In an embodiment, the normally closed valve further comprises a second limiting portion, which is arranged on the inner side wall of the second housing and protrudes away from the outer side wall of the second housing. In the second coil energized state, the spring moves in the direction close to the second coil until the fourth portion of the second spool abuts against the second limiting portion.

[0088] In an embodiment, a sealing ring can be arranged on the second spool 424 of the normally closed valve 42, which can be arranged between the fourth portion and the second limiting portion to enhance the sealing of the second spool 424 and prevent the cooling liquid from seeping into the normally closed valve in the absence of fire.

[0089] Figure 8 A working architecture schematic diagram of the fireproof device of the embodiment is shown. As shown, the battery management system BMS can be electrically connected with a plurality of battery modules, and the cooling liquid storage tank is in communication with the liquid cooling pipeline. When the battery pack reaches the combustion temperature threshold, the battery management system BMS can control the relay to disconnect the main loop current, and the cooling liquid is sprayed out of the normally closed valve, and the short circuit of the battery system caused by the spraying of the cooling liquid is prevented, thereby avoiding the initiation of more serious fire. Figure 8

[0090] In addition, the application also provides a fireproof method, which comprises: detecting the current temperature of the battery pack; closing the normally open valve according to the first energizing signal issued by the battery management system in the case that the current temperature of the battery pack exceeds the preset combustion temperature threshold, to block the flow of the cooling liquid in the liquid cooling pipeline; and opening the normally closed valve according to the second energizing signal issued by the battery management system in the case that the current temperature of the battery pack exceeds the preset combustion temperature threshold, to make the cooling liquid in the liquid cooling pipeline spray the battery cells in the battery pack. For specific details of the fireproof method, reference can be made to the description of the fireproof device, which will not be repeated here.

[0091] In summary, by arranging the normally open valve and at least one normally closed valve in the fireproof device, the application can solve the problem of high difficulty in extinguishing the fire at the initial stage of the battery pack, especially when there is a lack of fire extinguisher and water source nearby, the loss of the occupant and the vehicle can be reduced. By using the cooling liquid to spray the internal modules of the battery pack, the safety of the vehicle and the occupant is saved at the cost of the battery pack, and the problem that it is difficult for the personnel to extinguish the fire from outside when the battery pack is on fire is solved. In addition, by using the liquid cooling system to automatically extinguish the fire from the inside at the initial stage of the battery pack, the situation of personnel burns caused by the unprofessional occupant extinguishing the fire is avoided, and the safety of the battery system is improved.

[0092] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments. ​

[0093] The above describes in detail the fireproof device for the battery system, the battery system and the fireproof method provided by the embodiments of the present application. The principles and implementation manners of the present application are described by applying specific examples. The above description of the embodiments is only used to help understand the technical solutions of the present application and the core ideas thereof. It should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features thereof can be replaced equivalently. The modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A fire prevention device for a battery system, characterized in that: The battery system includes a battery pack and a battery management system electrically connected to the battery pack, and the fire prevention device includes: a temperature detection unit electrically connected to the battery management system, the temperature detection unit comprising a plurality of temperature detection switches disposed within the battery pack, the plurality of temperature detection switches being configured to detect the current temperature of the battery pack. When the battery pack reaches a combustion temperature threshold, the battery management system controls a relay to disconnect the main circuit current of the battery module; a normally-open valve electrically connected to the battery management system, the normally-open valve being disposed on a liquid-cooling pipe of the battery pack, the liquid-cooling pipe including a water inlet and a water outlet, the normally-open valve being configured to close in response to a first power-on signal issued by the battery management system when the current temperature of the battery pack exceeds a preset combustion temperature threshold, thereby blocking the flow of coolant in the liquid-cooling pipe; a first liquid flow channel and a first magnetic valve assembly being internally disposed within the normally-open valve, the first liquid flow channel being in communication with the liquid-cooling pipe, the first magnetic valve assembly including a first coil and a first magnetic valve, the first magnetic valve being located within a magnetic field generated by energizing the first coil to close the first liquid flow channel; At least one normally closed valve, a second liquid flow channel and a second magnetic valve assembly are provided inside the normally closed valve, the second magnetic valve assembly includes a second coil and a second magnetic valve, the second magnetic valve is located in the magnetic field generated by the second coil being energized to connect the second liquid flow channel with the liquid cooling pipe, the normally closed valve is electrically connected to the battery management system and mechanically connected to the liquid cooling pipe, the normally closed valve is arranged inside the battery pack and is located between the water inlet and the normally open valve, the normally closed valve is configured to open according to a second power-on signal issued by the battery management system when the current temperature of the battery pack exceeds a preset combustion temperature threshold, so that the coolant in the liquid cooling pipe is sprayed on the battery cells in the battery pack.

2. The fire protection device for a battery system according to claim 1, characterized in that: The normally open valve also includes a first shell, the first liquid flow channel and the first magnetic valve assembly are arranged inside the first shell, the first coil is sleeved on the top of the first shell, and the first coil is configured to generate a first magnetic force when energized.

3. The fire protection device for a battery system according to claim 2, characterized in that: The first magnetic valve includes a first magnet and a first valve core, the first magnet is in contact with the first valve core, the first coil is sleeved on at least a portion of the outer wall of the first magnet, and the first magnetic valve is configured so that the first magnet moves in a direction away from the first coil under the action of the first magnetic force, and the first magnet pushes the first valve core to move in a direction away from the first coil and close the first liquid flow channel.

4. The fire protection device for a battery system according to claim 3, characterized in that: A first valve core channel is provided in the first valve core, and the normally open valve is configured such that when the first coil is powered off, the first valve core channel is connected to the first liquid flow channel; when the first coil is powered on, the first magnet moves in a direction away from the first coil under the action of the first magnetic force, and the first magnet pushes the first valve core to move in a direction away from the first coil, and the first valve core channel is misaligned with the first liquid flow channel to close the first liquid flow channel.

5. The fire protection device for a battery system according to claim 3, characterized in that: The first magnet includes a first part and a second part, and the outer diameter of the first part is smaller than that of the second part. The first coil is sleeved on the outer wall of the first part, and the end surface of the second part away from the first part contacts the first valve core.

6. The fire protection device for a battery system according to claim 3, characterized in that: The normally open valve also includes a first water nozzle and a second water nozzle. The first water nozzle, the first liquid flow channel and the second water nozzle are connected. The first water nozzle and the second water nozzle are respectively arranged on both sides of the first valve core and both pass through the first shell and connect with the liquid cooling pipe.

7. The fire protection device for a battery system according to claim 4, characterized in that: The normally open valve also includes a first elastic member, which contacts the end of the first valve core away from the first magnet. The first elastic member is configured to push the first valve core to move in a direction close to the first coil when the first coil is powered off until the first valve core channel is connected to the first liquid flow channel.

8. The fire protection device for a battery system according to claim 7, characterized in that: The first elastic member is a first spring, and the first spring is spirally arranged around the inner wall of the first shell.

9. The fire protection device for a battery system according to claim 7, characterized in that: The normally open valve further includes a first limiting portion, which is provided on the inner side wall of the first shell and protrudes in a direction away from the outer side wall of the first shell.

10. The fire protection device for a battery system according to any one of claims 1 to 9, characterized in that: The normally open valve is arranged at a position adjacent to the water outlet of the liquid cooling pipe.

11. The fire protection device for a battery system according to any one of claims 3 to 9, characterized in that: The first magnet is in a T-shaped structure.

12. The fire protection device for a battery system according to claim 1, characterized in that: The normally closed valve also includes a second shell, the second liquid flow channel and the second magnetic valve assembly are arranged inside the second shell, the second coil is sleeved on the top of the second shell, and the second coil is configured to generate a second magnetic force when energized.

13. The fire protection device for a battery system according to claim 12, characterized in that: The second magnetic valve includes a second magnet and a second valve core, the second magnet is in contact with the second valve core, the second coil is sleeved on at least a portion of the outer wall of the second magnet, and the second magnetic valve is configured so that the second magnet moves in a direction away from the second coil under the action of the second magnetic force, and the second magnet pushes the second valve core to move in a direction away from the second coil, so that the second liquid flow channel is connected to the liquid cooling pipe.

14. The fire protection device for a battery system according to claim 13, characterized in that: A second valve core channel is provided in the second valve core, and the normally closed valve is configured such that when the second coil is de-energized, the second valve core channel is disconnected from the second liquid flow channel; when the second coil is energized, the second magnet moves in a direction away from the second coil under the action of the second magnetic force, and the second magnet pushes the second valve core to move in a direction away from the second coil, and the second valve core channel is connected to the second liquid flow channel, so that the second liquid flow channel is opened.

15. The fire protection device for a battery system according to claim 13, characterized in that: The second magnet includes a third part and a fourth part, and the outer diameter of the third part is smaller than that of the fourth part. The second coil is sleeved on the outer wall of the third part, and the end surface of the fourth part away from the third part contacts the second valve core.

16. The fire protection device for a battery system according to claim 13, characterized in that: The normally closed valve further includes a third water nozzle, which is arranged on one side of the second valve core and passes through the second shell to connect with the liquid cooling pipe.

17. The fire protection device for a battery system according to claim 14, characterized in that: The normally closed valve also includes a second elastic member, which contacts the end of the second valve core away from the second magnet. The second elastic member is configured to push the second valve core to move in a direction away from the second coil when the second coil is energized until the second valve core opens the second liquid flow channel, and to push the second valve core to move in a direction close to the second coil after the second coil is de-energized until the second valve core closes the second liquid flow channel.

18. The fire protection device for a battery system according to claim 17, characterized in that: The second elastic member is a second spring, and the second spring is spirally arranged around the inner wall of the second shell.

19. The fire protection device for a battery system according to claim 17, characterized in that: The normally closed valve further includes a second limiting portion, which is provided on the inner side wall of the second shell and protrudes in a direction away from the outer side wall of the second shell.

20. The fire protection device for a battery system according to claim 1, characterized in that: The battery pack includes a plurality of battery cell modules, and the normally closed valve is arranged in a gap between two adjacent battery cell modules along the direction in which the liquid cooling pipe is arranged.

21. A battery system, characterized in that: The battery system includes the fire protection device according to any one of claims 1 to 20.

22. A fire prevention method, characterized in that: The fire prevention method is applied to the fire prevention device according to any one of claims 1 to 20, and the fire prevention method comprises: detecting a current temperature of the battery pack; closing the normally open valve according to a first power-on signal sent by the battery management system when the current temperature of the battery pack exceeds a preset combustion temperature threshold, so as to block the flow of coolant in the liquid cooling pipe; The normally closed valve is opened according to a second power-on signal sent by the battery management system when the current temperature of the battery pack exceeds a preset combustion temperature threshold, so that the coolant in the liquid cooling pipe sprays the battery cells in the battery pack.

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