Battery thermal runaway early warning protection system based on BMS (Battery Management System)

Abstract

The invention relates to a battery thermal runaway early warning protection system based on a BMS system in the field of battery thermal management, when a single cylindrical battery cell in a battery pack abnormally heats, the abnormal single cylindrical battery cell and adjacent cylindrical battery cells around the abnormal single cylindrical battery cell are all powered off, heat transfer among different cylindrical battery cells is reduced, and the battery thermal runaway early warning protection system based on the BMS system is achieved. The abnormal cylindrical battery cell is cooled by injecting a certain amount of coolant; when the temperature continues to rise after the quantitative coolant is injected, the coolant is continuously injected, and the quantitative coolant is injected to the adjacent cylindrical battery cells, so that the cooling effect is improved, the adjacent cylindrical battery cells are further protected, and heat is timely discharged by arranging an exhaust pipe; and when the temperature of the abnormal cylindrical battery core exceeds the thermal failure temperature, all the other cylindrical battery cores are powered off, and a coolant is continuously filled into the protective cylinders of the adjacent cylindrical battery cores at the periphery, so that the adjacent cylindrical battery cores are further protected.

Description

Technical Field

[0001] The present invention relates to an early warning protection system, and in particular to a battery thermal runaway early warning protection system based on a BMS system, which is applied in the field of battery thermal management. Background Art

[0002] The current battery thermal management system mainly covers a monitoring and sensing module, a power-off protection module, and a thermal management cooling module. However, in order to increase the volume energy density of the battery pack, existing design schemes generally adopt a flat arrangement of cylindrical cells, and only thermal insulation barriers are configured between adjacent cells. When this layout encounters a thermal runaway event of a single cell, heat can easily be quickly transferred to adjacent cylindrical cells, thereby triggering a chain reaction of thermal runaway, which may cause the entire battery pack to fail and be scrapped in severe cases.

[0003] The existing patent with publication number CN117335052B discloses a battery pack thermal runaway protection system and method based on battery cell data analysis, which belongs to the field of power battery technology. The battery pack is composed of multiple battery modules, and the battery module includes multiple columns of battery cells. The protection system includes a BMS system, a central processing module and a thermal management system; the thermal management system is used to collect the temperature information of each column of battery cells and cool the battery cells with a thermal protection module and a medium conveying module. In the present invention, the BMS system cooperates with the central processing module to analyze the battery cell data. When the battery cells are in an abnormal state, the medium conveying module cooperates with the thermal protection module to actively dissipate the heat of the battery module to prevent micro-short circuits inside the battery cells, reduce safety hazards, and increase the service life of the battery pack. The thermal protection module can self-adjust the cooling capacity while detecting the temperature, reduce energy waste, and achieve timely heat dissipation of the battery module.

[0004] The above patent uses a variety of data analyses to actively and accurately dissipate heat from battery cells, but it does not solve the problem that once thermal runaway occurs in a single battery cell, thermal runaway is prone to propagate, resulting in large thermal runaway losses. Summary of the invention

[0005] In view of the above-mentioned prior art, the technical problem to be solved by the present invention is that the existing battery thermal management system cannot solve the problem that thermal runaway is prone to propagation after thermal runaway of a single battery cell.

[0006] In order to solve the above problems, the present invention provides a battery thermal runaway early warning protection system based on a BMS system, comprising a battery pack and a battery controller equipped with the early warning system; the battery pack comprises an outer shell, an inner shell is fixedly connected inside the outer shell, a plurality of protective cylinders vertically penetrating the inner shell are fixedly connected to the inner shell, a mounting sleeve is fixedly connected inside each protective cylinder, a cylindrical battery cell is fixedly connected inside the mounting sleeve, a plurality of guide grooves distributed in a circumference are opened on the inner wall of the mounting sleeve, a temperature sensor arranged opposite to the cylindrical battery cell is fixedly connected in the guide groove, a heat exchange cavity for insulating heat transfer oil to flow is formed between the outer wall of the protective cylinder and the inner wall of the inner shell, an oil inlet pipe and an oil outlet pipe arranged on both sides thereof and connected to the heat exchange cavity are fixedly connected to the inner shell, and both the oil inlet pipe and the oil outlet pipe are connected to an external heat transfer oil circulation device;

[0007] An upper power-off mechanism and a lower power-off mechanism with the same structure and mirror-image arrangement are provided at the upper and lower ends of the protective tube. The upper power-off mechanism includes an end cap threadedly connected to the protective tube, a lifting plate slidably connected to the end cap, a conductive sheet in contact with the cylindrical battery cell electrode fixedly connected inside the lifting plate, the conductive sheet extending to the outside of the end cap and movably connected to the external battery cell bus, a magnet ring fixedly connected inside the lifting plate, and an electromagnetic coil matched with the magnet ring fixedly connected inside the end cap;

[0008] A central tube connected to the inner cavity of the protective tube is fixedly connected in the middle of the end cover, and a valve core rod for controlling the open and closed state of the central tube is arranged in the central tube, and the lower end of the valve core rod extends to the bottom of the central tube and is arranged opposite to the lifting plate, and the lifting plate pushes the valve core rod to move so that the central tube switches between the closed state and the open state; the upper end of the central tube of the upper power-off mechanism is fixedly connected to a cooling tube located above the protective tube, and the cooling tube is connected to the coolant storage tank, and an electromagnetic flow valve is fixedly connected to the connection between the two, and the lower end of the central tube of the lower power-off mechanism is fixedly connected to an exhaust pipe located below the protective tube, and the exhaust pipe is connected to the external atmosphere, and a smoke sensor is fixedly connected to the outlet position of the outer end of the exhaust pipe;

[0009] The early warning system includes a control module, the input end of the control module is respectively connected to a temperature monitoring module and a smoke monitoring module, the input end of the temperature monitoring module is connected to a temperature sensor, the input end of the smoke monitoring module is connected to a smoke sensor, the output end of the control module is respectively connected to an early warning module and a power-off cooling module, the output end of the early warning module is respectively connected to a display screen and a buzzer alarm light, and two sets of electromagnetic coils of an upper power-off mechanism and a lower power-off mechanism and an electromagnetic flow valve are all connected to the output end of the power-off cooling module.

[0010] In the above-mentioned battery thermal runaway early warning and protection system based on the BMS system, a protective tube, a pair of power-off mechanisms, a cooling pipe and an exhaust pipe are provided to cut off power, cool and exhaust smoke to a single abnormal cylindrical battery cell and adjacent cylindrical battery cells according to temperature changes, thereby reducing the spread of thermal runaway.

[0011] As a further improvement of the present application, the conductive sheet includes a U-shaped portion and a pair of arc-shaped portions fixed at both ends thereof, the outer end of the arc-shaped portion is fixedly connected to a horizontal portion, and the lower end of the U-shaped portion is fixedly connected to a columnar portion, and the columnar portion is used to contact the electrode of the cylindrical battery cell; a plurality of wiring mechanisms located between adjacent protective cylinders are fixedly connected to the inner shell, and the wiring mechanism includes a conical cylinder, and a jumper is provided in the conical cylinder, the horizontal portions of adjacent conductive sheets are inserted into the conical cylinder and abut against the jumper, and the upper end of the jumper is rotatably connected to a locking bolt threadedly connected to the conical cylinder; the end cover includes an externally threaded ring threadedly connected to the inner wall of the protective cylinder and a rotating disk located on the inner side of the externally threaded ring and rotatably connected to the same, and the lifting disk is slidably connected to the rotating disk.

[0012] As a further improvement of the present application, the guide groove is a vertical groove opened on the inner wall of the mounting sleeve, the vertical length of the guide groove is greater than the vertical height of the cylindrical battery cell, the protective tube and the mounting sleeve are both cylindrical structures with openings at both ends, and both are made of insulating thermally conductive material, which is one of polystyrene, high thermal conductivity epoxy resin, and alumina.

[0013] As a further improvement of the present application, the lifting plate includes a boss that slides against the inner wall of the protective tube, a sliding plate is fixedly connected to the boss, the sliding plate passes through the end cover and is slidably connected to the end cover, and scattered holes are opened on the outside of the sliding plate.

[0014] As a further improvement of the present application, a pair of guide rods passing through the lifting plate are fixedly connected to the end cover, a first spring located between the end cover and the lifting plate is sleeved on the guide rods, and a vertically arranged first electric telescopic rod and a second electric telescopic rod are fixedly connected to the inner wall of the protective tube.

[0015] As a further improvement of the present application, the center tube is a vertical circular tube and is fixedly connected internally with a radial support rod with a circular cross-section passing through it. The valve core rod is a round rod with an I-shaped cross-section. The valve core rod passes through the radial support rod and is slidably connected thereto. A second spring that abuts the radial support rod is sleeved on the lower part of the valve core rod. A vent hole with an inner diameter smaller than the upper diameter of the valve core rod is opened on the side of the center tube away from the radial support rod. The upper part of the valve rod covers the upper end of the vent hole under the action of the second spring.

[0016] As a further improvement of the present application, the truncated cone cylinder is a truncated cone-shaped structure, a through cavity is opened at the lower part for the horizontal part to be inserted, and the overlapping piece is slidably nested in the through cavity.

[0017] As a further improvement of the present application, the outer shell is a hollow box structure and is provided with a detachable top plate and bottom plate, and the outer ends of multiple conical cylinders distributed up and down are threadedly connected with fixing bolts that penetrate the top plate or the bottom plate.

[0018] As a further improvement of the present application, the early warning system includes the following steps when working:

[0019] Step 1: The temperature monitoring module monitors the temperature of each cylindrical battery cell through a temperature sensor, and the control module compares the operating temperature of the cylindrical battery cell with the operating temperature threshold. When the operating temperature of at least one cylindrical battery cell exceeds the normal operating temperature threshold, step 2 is executed, otherwise, no operation is performed;

[0020] Step 2: The power-off cooling module controls the corresponding electromagnetic coil and electromagnetic flow valve to power off the abnormal cylindrical battery cell and inject a first dose of coolant into the protective tube where the abnormal cylindrical battery cell is located. At the same time, the power-off cooling module powers off the adjacent cylindrical battery cells around the abnormal cylindrical battery cell, and issues a first-level warning through the early warning module to remind users to pay attention to the abnormal cylindrical battery cell and repair it in time, and then execute step 3;

[0021] Step 3: When it is monitored that the temperature of the abnormal cylindrical battery cell continues to rise after the coolant is injected, step 4 is executed; when it is monitored that the temperature of the abnormal cylindrical battery cell gradually decreases to the ambient temperature, step 5 is executed;

[0022] Step 4: The power-off cooling module controls the electromagnetic flow valve and the corresponding electromagnetic coil to connect the central tube below the abnormal cylindrical battery cell with the exhaust pipe, and continuously injects coolant into the protective cylinder where the abnormal cylindrical battery cell is located; at the same time, a second dose of coolant is injected into the protective cylinders of adjacent cylindrical batteries around the abnormal cylindrical battery cell through the same operation; in addition, a secondary warning is issued through the early warning module to remind the user to always pay attention to the temperature of the abnormal cylindrical battery cell, and then execute step 6;

[0023] Step 5: The power-off cooling module stops the injection of coolant by controlling the corresponding electromagnetic coil and electromagnetic flow valve, connects the adjacent cylindrical cells around the abnormal cylindrical cell, records the position of the abnormal cylindrical cell, and then executes step 1;

[0024] Step 6: When it is monitored that the temperature of the abnormal cylindrical battery cell exceeds the thermal runaway temperature, step 7 is executed; when it is monitored that the temperature of the abnormal cylindrical battery cell gradually decreases to the ambient temperature and the flue gas sensor does not detect the presence of flue gas at the exhaust pipe, step 5 is executed;

[0025] Step 7: continuously inject coolant into the protective tube where the adjacent cylindrical cells are located, and cut off the power to all other cylindrical cells. The warning module issues a level 3 warning to remind users to stay away from the battery pack and keep a safe distance, and then execute step 8.

[0026] Step eight, when the temperature of the abnormal cylindrical battery cell gradually drops to the ambient temperature and no smoke is discharged from the exhaust pipe, the power-off cooling module stops the injection of coolant by controlling the electromagnetic flow valve, and sends a four-level warning through the early warning module to remind users to stop using the battery pack and repair it in time.

[0027] To summarize, when a single cylindrical battery cell in the battery pack generates abnormal heat, the present invention quickly senses the abnormal temperature rise by providing a temperature monitoring module and a power-off cooling module, and powers off the abnormal single cylindrical battery cell and the adjacent cylindrical battery cells around it to reduce the transfer of heat between different cylindrical battery cells, and cools the abnormal cylindrical battery cell by adding a predetermined amount of coolant, and continuously monitors the temperature. When the temperature continues to rise after the coolant is added, the coolant is continuously added to the adjacent cylindrical battery cells and a predetermined amount of coolant is added to improve the cooling effect, and the adjacent cylindrical battery cells are further protected, and the heat is discharged in time by providing an exhaust pipe; when the temperature of the abnormal cylindrical battery cell exceeds the thermal failure temperature, all other cylindrical battery cells are powered off, and coolant is continuously added to the protective tubes of the adjacent cylindrical battery cells to further protect the adjacent cylindrical battery cells; in addition, through the early warning module, the early warning module issues different early warnings according to the heating conditions of the cylindrical battery cells, which is convenient for operators to take corresponding measures. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the three-dimensional structure of the battery pack in this application;

[0029] Figure 2 This is a schematic diagram of the exploded assembly of the battery pack in this application;

[0030] Figure 3 This is a module diagram of the early warning system in this application;

[0031] Figure 4 This is the workflow diagram of the early warning system in this application;

[0032] Figure 5 It is a schematic diagram of the cross-sectional structure of the battery pack in this application;

[0033] Figure 6 for Figure 5 A schematic diagram of the enlarged structure at A in the middle;

[0034] Figure 7 for Figure 5 A schematic diagram of the enlarged structure at B in the middle;

[0035] Figure 8 for Figure 5 Schematic diagram of the enlarged structure at C in the middle;

[0036] Fig. 9 This is a schematic diagram of the power-off state of the cylindrical battery in this application;

[0037] Fig.10 This is a schematic diagram of the coolant injection state in this application;

[0038] Fig.11This is a schematic diagram of the explosion assembly of the lifting plate and the end cover;

[0039] Fig.12 for Figure 5 Schematic diagram of the enlarged structure at D in the middle.

[0040] Description of the numbers in the figure:

[0041] 1. Outer shell; 2. Inner shell; 3. Protective tube; 4. Cylindrical battery cell; 5. Mounting sleeve; 501. Guide groove; 6. Upper power-off mechanism; 7. Lower power-off mechanism; 8. End cover; 801. External thread ring; 802. Rotating plate; 9. Lifting plate; 901. Boss; 902. Dispersion hole; 903. Sliding plate; 10. Guide rod; 11. First spring; 12. Conductive sheet; 1201. U-shaped portion; 1202. Columnar portion; 1203. Arc-shaped portion; 1204 , horizontal part; 13, magnet ring; 14, electromagnetic coil; 15, first electric telescopic rod; 16, second electric telescopic rod; 17, center tube; 18, valve core rod; 19, second spring; 20, cooling tube; 21, electromagnetic flow valve; 22, exhaust pipe; 23, flue gas sensor; 24, temperature sensor; 25, oil inlet pipe; 26, oil outlet pipe; 27, truncated cone; 2701, through cavity; 28, overlap plate; 29, locking bolt; 30, fixing bolt. DETAILED DESCRIPTION

[0042] The following describes two implementation modes of the present application in detail with reference to the accompanying drawings.

[0043] The first implementation method:

[0044] Figure 1-10 A battery thermal runaway early warning and protection system based on a BMS system is shown, comprising a battery pack and a battery controller equipped with the early warning system; the battery pack comprises an outer shell 1, an inner shell 2 is fixedly connected inside the outer shell 1, a plurality of protective cylinders 3 vertically penetrating the inner shell 2 are fixedly connected to the inner shell 2, a mounting sleeve 5 is fixedly connected inside each protective cylinder 3, a cylindrical battery cell 4 is fixedly connected inside the mounting sleeve 5, a plurality of guide grooves 501 distributed in a circumference are opened on the inner wall of the mounting sleeve 5, a temperature sensor 24 arranged opposite to the cylindrical battery cell 4 is fixedly connected inside the guide groove 501, a heat exchange cavity for the flow of insulating heat transfer oil is formed between the outer wall of the protective cylinder 3 and the inner wall of the inner shell 2, an oil inlet pipe 25 and an oil outlet pipe 26 arranged on both sides thereof and connected to the heat exchange cavity are fixedly connected to the inner shell 2, and both the oil inlet pipe 25 and the oil outlet pipe 26 are connected to an external heat transfer oil circulation device;

[0045] See also Figure 5 and Figure 6, the upper and lower ends of the protective tube 3 are provided with an upper power-off mechanism 6 and a lower power-off mechanism 7 with the same structure and mirror-image arrangement, the upper power-off mechanism 6 includes an end cover 8 threadedly connected to the protective tube 3, a lifting plate 9 is slidably connected to the end cover 8, a conductive sheet 12 in contact with the electrode of the cylindrical battery cell 4 is fixedly connected inside the lifting plate 9, the conductive sheet 12 extends to the outside of the end cover 8 and is movably connected to the external battery bus, a magnet ring 13 is fixedly connected inside the lifting plate 9, an electromagnetic coil 14 cooperating with the magnet ring 13 is fixedly connected inside the end cover 8, the electromagnetic coil 14 is started, and the magnetic field generated by the electromagnetic coil 14 magnetically attracts the magnet ring 13 to drive it to move vertically, and the magnet ring 13 drives the lifting plate 9 and the conductive sheet 12 therein to separate from the electrode of the cylindrical battery cell 4;

[0046] See also Figure 5 and Figure 6 , a central tube 17 connected to the inner cavity of the protective tube 3 is fixedly connected in the middle of the end cover 8, a valve core rod 18 for controlling the open and closed state of the central tube 17 is arranged in the central tube 17, the lower end of the valve core rod 18 extends to the bottom of the central tube 17 and is arranged opposite to the lifting plate 9, the lifting plate 9 pushes the valve core rod 18 to move so that the central tube 17 switches between the closed state and the open state; the upper end of the central tube 17 of the upper power-off mechanism 6 is fixedly connected to a cooling tube 20 located above the protective tube 3, the cooling tube 20 is connected to the coolant storage tank and an electromagnetic flow valve 21 is fixedly connected at the connection between the two, the lower end of the central tube 17 of the lower power-off mechanism 7 is fixedly connected to an exhaust pipe 22 located below the protective tube 3, the exhaust pipe 22 is connected to the external atmosphere, and a smoke sensor 23 is fixedly connected to the outlet position of the outer end of the exhaust pipe 22;

[0047] See also Figure 2 , Figure 3 and Figure 6-8 The early warning system includes a control module, the input end of the control module is respectively connected to the temperature monitoring module and the smoke monitoring module, the input end of the temperature monitoring module is connected to the temperature sensor 24, the input end of the smoke monitoring module is connected to the smoke sensor 23, the output end of the control module is respectively connected to the early warning module and the power-off cooling module, the output end of the early warning module is respectively connected to the display screen and the buzzer alarm light, the two sets of electromagnetic coils 14 of the upper power-off mechanism 6 and the lower power-off mechanism 7 and the electromagnetic flow valve 21 are all connected to the output end of the power-off cooling module.

[0048] Specifically, when the cylindrical battery cell 4 needs to be powered off, one of the two groups of electromagnetic coils 14 of the upper power-off mechanism 6 and the lower power-off mechanism 7 is started, so that the conductive sheet 12 on one side of the cylindrical battery cell 4 is out of contact with the abnormal cylindrical battery cell 4, thereby achieving power off of the abnormal cylindrical battery cell 4; when the cylindrical battery cell 4 needs to be cooled, the electromagnetic coil 14 of the upper power-off mechanism 6 is started, so that the lifting plate 9 pushes the valve core rod 18 in the central tube 17 to move so that the central tube 17 is connected to the cooling tube 20; when the coolant is needed to continuously cool the cylindrical battery cell 4, the two groups of electromagnetic coils 14 of the upper power-off mechanism 6 and the lower power-off mechanism 7 are started at the same time, so that the central tubes 17 on the upper and lower sides are connected to the cooling tube 20 and the exhaust pipe 22 respectively, so that the coolant continuously flows through the surface of the cylindrical battery cell 4 through the guide groove 501 of the mounting sleeve 5, thereby achieving continuous cooling.

[0049] See also Figure 4 , the early warning system includes the following steps when working:

[0050] Step 1: The temperature monitoring module monitors the temperature of each cylindrical battery cell 4 through the temperature sensor 24, and the control module compares the operating temperature of the cylindrical battery cell 4 with the operating temperature threshold. When the operating temperature of at least one cylindrical battery cell 4 exceeds the normal operating temperature threshold, step 2 is executed, otherwise, no operation is performed;

[0051] Step 2: The power-off cooling module controls the corresponding electromagnetic coil 14 and the electromagnetic flow valve 21 to power off the abnormal cylindrical battery cell 4 and inject a first dose of coolant into the protective tube 3 where the abnormal cylindrical battery cell 4 is located. At the same time, the power-off cooling module powers off the adjacent cylindrical battery cells 4 around the abnormal cylindrical battery cell 4, and issues a first-level warning through the early warning module to remind the user to pay attention to the abnormal cylindrical battery cell 4 and repair it in time, and then execute step 3;

[0052] Specifically, the power-off cooling module starts the electromagnetic coil 14 and the electromagnetic flow valve 21 of the upper power-off mechanism 6 above the abnormal cylindrical battery cell 4, and the electromagnetic coil 14 drives the lifting plate 9 to move upward, and the lifting plate 9 drives the conductive sheet 12 to separate from the abnormal cylindrical battery cell 4, and then the lifting plate 9 continues to move upward, and the lifting plate 9 pushes the valve core rod 18 to move, so that the central tube 17 is connected with the cooling tube 20, and the coolant in the coolant tank is injected into the protective tube 3 where the abnormal cylindrical battery cell 4 is located through the electromagnetic flow valve 21 and the cooling tube 20; similarly, by controlling the electromagnetic coil 14 corresponding to the adjacent cylindrical battery cell 4, the adjacent cylindrical battery cell 4 is disconnected from the corresponding conductive sheet 12 and the power is cut off; it should be noted that the first volume is a manually set value, and the injection amount of the coolant is controlled by the electromagnetic flow valve 21;

[0053] It should be noted that a quantitative amount of coolant is added to the abnormally heated cylindrical battery core 4 to cool it down and suppress the tendency of further temperature rise, so as to suppress the thermal runaway of the cylindrical battery core 4;

[0054] Step 3: When it is monitored that the temperature of the abnormal cylindrical battery core 4 continues to rise after the coolant is injected, step 4 is executed; when it is monitored that the temperature of the abnormal cylindrical battery core 4 gradually decreases to the ambient temperature, step 5 is executed;

[0055] Step 4: The power-off cooling module controls the electromagnetic flow valve 21 and the corresponding electromagnetic coil 14 to connect the central tube 17 below the abnormal cylindrical battery cell 4 with the exhaust pipe 22, and continuously injects the coolant into the protective cylinder 3 where the abnormal cylindrical battery cell 4 is located; at the same time, the second dose of coolant is injected into the protective cylinder 3 of the adjacent cylindrical battery cells 4 around the abnormal cylindrical battery cell 4 through the same operation; in addition, a secondary warning is issued through the early warning module to remind the user to always pay attention to the temperature of the abnormal cylindrical battery cell 4, and then execute step 6;

[0056] Specifically, the power-off cooling module starts the electromagnetic coil 14 of the lower power-off mechanism 7 below the abnormal cylindrical battery cell 4, and the lifting plate 9 of the lower power-off mechanism 7 moves downward, pushing the valve core rod 18 in the central tube 17 of the lower power-off mechanism 7 to move downward, so that the central tube 17 of the lower power-off mechanism 7 is connected with the exhaust pipe 22, so that the coolant flows through the cooling pipe 20 and the protective tube 3 and is discharged from the exhaust pipe 22, thereby increasing the cooling amount. At the same time, by injecting a certain amount of coolant into the adjacent protective tube 3, the heat transfer to the surrounding adjacent cylindrical battery cells 4 is reduced, thereby protecting the adjacent cylindrical battery cells 4;

[0057] It should be noted that, when the quantitative coolant cannot suppress the continued temperature rise of the cylindrical battery core 4, continuous coolant filling is performed to further suppress the temperature rise trend;

[0058] Step 5: The power-off cooling module stops the injection of coolant by controlling the corresponding electromagnetic coil 14 and the electromagnetic flow valve 21, connects the adjacent cylindrical battery cells 4 around the abnormal cylindrical battery cell 4, and records the position of the abnormal cylindrical battery cell 4, and then executes step 1;

[0059] Step 6: When it is detected that the temperature of the abnormal cylindrical battery cell 4 exceeds the thermal runaway temperature, step 7 is executed; when it is detected that the temperature of the abnormal cylindrical battery cell 4 gradually decreases to the ambient temperature and the flue gas sensor 23 does not detect the presence of flue gas at the exhaust pipe 22, step 5 is executed;

[0060] Specifically, after the abnormal cylindrical battery cell 4 is injected with the first volume of coolant, the temperature drops to the ambient temperature, indicating that the abnormal cylindrical battery cell 4 has only abnormally heated up and has not developed into a thermal runaway state, and thus the abnormal cylindrical battery cell 4 is stopped from being used, and the adjacent cylindrical battery cells 4 around the abnormal cylindrical battery cell 4 are reconnected to maintain the maximum available power of the battery pack;

[0061] Step 7: continuously inject coolant into the protective tube 3 where the adjacent cylindrical battery cells 4 are located, and cut off the power supply to all other cylindrical battery cells 4. A three-level warning is issued through the warning module to remind users to stay away from the battery pack and keep a safe distance, and then execute step 8;

[0062] Specifically, by starting the electromagnetic coil 14 under the adjacent cylindrical battery core 4, the central tube 17 under the protective tube 3 where the adjacent cylindrical battery core 4 is located is connected with the exhaust pipe 22, and the coolant is continuously injected;

[0063] Step eight, when the temperature of the abnormal cylindrical battery cell 4 gradually drops to the ambient temperature and there is no smoke discharged from the exhaust pipe 22, the power-off cooling module stops the injection of coolant by controlling the electromagnetic flow valve 21, and issues a four-level warning through the early warning module to remind the user to stop using the battery pack and perform timely maintenance.

[0064] It should be noted that in the event of a clear thermal runaway, the cylindrical battery cells 4 of the entire battery pack are powered off in a timely manner, and coolant is continuously injected into the adjacent protective tubes 3 around the thermal runaway cylindrical battery cells 4 to reduce heat transfer, protect the surrounding and other cylindrical battery cells 4 outside the surrounding areas, reduce overall losses, and reduce the severity of the thermal failure reaction by the flowing coolant. The heat and generated smoke are removed from the protective tube 3 by the flowing coolant and the exhaust pipe 22, reducing the internal pressure of the protective tube 3 and reducing the heat transfer between the cylindrical battery cells 4, so that the thermal failure reaction is under control and the overall loss is reduced.

[0065] Compared with the traditional battery thermal management system, when a single cylindrical battery cell 4 generates abnormal heat, the present invention quickly senses the abnormal temperature rise by providing a temperature monitoring module and a power-off cooling module, and powers off the abnormal single cylindrical battery cell 4 and the adjacent cylindrical battery cells 4 around it, thereby reducing the heat transfer between different cylindrical battery cells 4, and cooling the abnormal cylindrical battery cell 4 by adding a predetermined amount of injection coolant, and continuously monitoring the temperature. When the temperature continues to rise after the injection of coolant, the coolant is continuously injected into the adjacent cylindrical battery cells 4 to improve the cooling effect, further protect the adjacent cylindrical battery cells 4, and the heat is discharged in time by providing an exhaust pipe 22; when the temperature exceeds the thermal failure temperature, all other cylindrical battery cells 4 are powered off, and the protective tube 3 of the adjacent cylindrical battery cells 4 is continuously injected with coolant to further protect the adjacent cylindrical battery cells 4; in addition, through the early warning module, the early warning module issues different early warnings according to the heating conditions of the cylindrical battery cells 4, so that the operator can take corresponding measures.

[0066] See also Figure 6 The guide groove 501 is a vertical groove opened on the inner wall of the installation sleeve 5 , and the vertical length of the guide groove 501 is greater than the vertical height of the cylindrical battery core 4 .

[0067] Specifically, the coolant can fully contact the outer wall of the cylindrical battery core 4 through the guide groove 501, thereby improving the cooling effect.

[0068] In this embodiment, the protective tube 3 and the installation sleeve 5 are both cylindrical structures with openings at both ends, and both are made of insulating thermally conductive material, which is one of polystyrene, high thermal conductivity epoxy resin, and alumina.

[0069] Specifically, each cylindrical battery cell 4 is isolated and wrapped by the protective tube 3, and insulating heat-conducting oil is filled in the heat exchange cavity, so as to reduce the current breakdown occurring when the cylindrical battery cell 4 has thermal runaway, reduce the propagation speed of the thermal runaway, and reduce the loss caused by the thermal runaway of a single cylindrical battery cell 4.

[0070] See also Figure 6 and Fig.10 The lifting plate 9 includes a boss 901 that is slidably abutted against the inner wall of the protective tube 3, and a sliding plate 903 is fixedly connected to the boss 901. The sliding plate 903 passes through the end cover 8 and is slidably connected to the end cover 8. A dispersion hole 902 is opened on the boss 901 at the outer side of the sliding plate 903.

[0071] Specifically, the coolant enters the top of the lifting plate 9 through the central tube 17 and is then injected into the wall below the lifting plate 9 from the dispersion holes 902, so that the coolant is evenly dispersed and the cooling effect is improved.

[0072] See also Figure 6A pair of guide rods 10 penetrating the lifting plate 9 are fixedly connected to the end cover 8 , and a first spring 11 located between the end cover 8 and the lifting plate 9 is sleeved on the guide rods 10 .

[0073] Specifically, the guide rod 10 is used to improve the stability of the lifting plate 9 moving up and down, and the first spring 11 is provided to enable the lifting plate 9 to squeeze the conductive sheet 12 onto the cylindrical battery cell 4 when no external force is applied, thereby maintaining the power supply state of the cylindrical battery cell 4.

[0074] See also Figure 6 A first electric telescopic rod 15 and a second electric telescopic rod 16 are fixedly connected to the inner wall of the protective tube 3 and are vertically arranged.

[0075] Specifically, when one of the first electric telescopic rod 15 and the second electric telescopic rod 16 is extended, the lifting plate 9 is limited. When the lifting plate 9 moves to the first electric telescopic rod 15 and the second electric telescopic rod 16, the conductive sheet 12 is separated from the cylindrical battery core 4. When the lifting plate 9 moves to above the second electric telescopic rod 16, the valve core rod 18 is squeezed to make the central tube 17 conductive.

[0076] See also Figure 6 The center tube 17 is a vertical circular tube and is fixedly connected to a radial support rod with a circular cross-section passing through it. The valve core rod 18 is a round rod with an I-shaped cross-section. The valve core rod 18 passes through the radial support rod and is slidably connected to it. The lower part of the valve core rod 18 is sleeved with a second spring 19 that abuts against the radial support rod. A vent hole with an inner diameter smaller than the upper diameter of the valve core rod 18 is opened on the side of the center tube 17 away from the radial support rod. The upper part of the valve type rod 18 covers the upper end of the vent hole under the action of the second spring 19 to close it.

[0077] Second implementation method:

[0078] Fig.11 and Fig.12A battery thermal runaway early warning protection system based on a BMS system is shown. On the basis of the first embodiment, the conductive sheet 12 includes a U-shaped portion 1201 and a pair of arc-shaped portions 1203 fixed at both ends thereof, the outer end of the arc-shaped portion 1203 is fixedly connected to a horizontal portion 1204, and the lower end of the U-shaped portion 1201 is fixedly connected to a columnar portion 1202, and the columnar portion 1202 is used to contact the electrode of the cylindrical battery cell 4; a plurality of wiring mechanisms located between adjacent protective cylinders 3 are fixedly connected to the inner shell 2, and the wiring mechanism includes a truncated cone cylinder 27, and a lap piece 28 is arranged in the truncated cone cylinder 27. The horizontal portion 1204 of the adjacent conductive sheet 12 is inserted into the truncated cone cylinder 27 and abuts against the lap piece 28, and the upper end of the lap piece 28 is rotatably connected to a locking bolt 29 threadedly connected to the truncated cone cylinder 27; the end cover 8 includes an external threaded ring 801 threadedly connected to the inner wall of the protective cylinder 3 and a rotating disk 802 located on the inner side of the external threaded ring 801 and rotatably connected to it, and the lifting disk 9 is slidably connected to the rotating disk 802.

[0079] See also Fig.12 The truncated cone tube 27 is a truncated cone structure, and a through cavity 2701 for the horizontal portion 1204 to be inserted is opened at the lower part, and the overlapping piece 28 is slidably nested in the through cavity 2701.

[0080] Specifically, when the damaged cylindrical battery cell 4 needs to be replaced, first, the locking bolts 29 of the wiring mechanisms on both sides of the cylindrical battery cell 4 to be replaced are screwed to disengage the conductive sheet 12 from the wiring mechanisms. When the conductive sheet 12 is separated from the cylindrical battery cell 4, the arc portion 1203 is bent, and then the external threaded ring 801 is screwed to remove the end cover 8 and the lifting plate 9 and the conductive sheet 12 connected thereto. Finally, the mounting sleeve 5 and the cylindrical battery cell 4 are disassembled, thereby realizing rapid disassembly and assembly of the cylindrical battery cell 4, improving the convenience of disassembly of the cylindrical battery cell 4, and at the same time, reducing the interference between the conductive sheet 12 and the end cover 8 when removing the end cover 8.

[0081] See also Fig.12 The outer shell 1 is a hollow box structure and is provided with a detachable top plate and bottom plate. The outer ends of multiple truncated cone cylinders 27 distributed up and down are threadedly connected with fixing bolts 30 that penetrate the top plate or the bottom plate.

[0082] Specifically, it is convenient to disassemble the outer shell 1, thereby realizing the rapid disassembly of the entire battery pack, and further improving the convenience of replacing and disassembling the cylindrical battery cell 4; at the same time, the protective cylinder 3 supports the inner shell 2, and the conical cylinder 27 supports the outer shell 1. The protective cylinder 3 and the conical cylinder 27 cooperate to improve the structural strength of the battery pack.

[0083] In view of current practical needs, the above-mentioned implementation mode adopted in this application is not limited to the scope of protection. Various changes made within the knowledge scope of technical personnel in this field without departing from the concept of this application still fall within the scope of protection of the present invention.

Claims

1. A battery thermal runaway early warning and protection system based on a BMS system, characterized in that: The invention comprises a battery pack and a battery controller equipped with an early warning system; the battery pack comprises an outer shell (1), an inner shell (2) is fixedly connected to the outer shell (1), a plurality of protective tubes (3) vertically penetrating the inner shell (2) are fixedly connected to the inner shell (2), a mounting sleeve (5) is fixedly connected to each protective tube (3), a cylindrical battery cell (4) is fixedly connected to the mounting sleeve (5), a plurality of guide grooves (501) distributed in a circumferential manner are opened on the inner wall of the mounting sleeve (5), a temperature sensor (24) arranged opposite to the cylindrical battery cell (4) is fixedly connected to the guide groove (501), a heat exchange cavity for insulating heat transfer oil to flow is formed between the outer wall of the protective tube (3) and the inner wall of the inner shell (2), an oil inlet pipe (25) and an oil outlet pipe (26) arranged on both sides of the inner shell (2) and connected to the heat exchange cavity are fixedly connected to the inner shell (2), and both the oil inlet pipe (25) and the oil outlet pipe (26) are connected to an external heat transfer oil circulation device; The upper and lower ends of the protective tube (3) are provided with an upper power-off mechanism (6) and a lower power-off mechanism (7) with the same structure and mirror-image arrangement. The upper power-off mechanism (6) comprises an end cover (8) threadedly connected to the protective tube (3). A lifting plate (9) is slidably connected to the end cover (8). A conductive sheet (12) in contact with the electrode of the cylindrical battery cell (4) is fixedly connected to the lifting plate (9). The conductive sheet (12) extends to the outside of the end cover (8) and is movably connected to an external battery cell bus. A magnet ring (13) is fixedly connected to the lifting plate (9). An electromagnetic coil (14) cooperating with the magnet ring (13) is fixedly connected to the end cover (8). The middle part of the end cover (8) is fixedly connected with a central tube (17) which is in communication with the inner cavity of the protective tube (3). A valve core rod (18) for controlling the open and closed state of the central tube (17) is arranged in the central tube (17). The lower end of the valve core rod (18) extends to the bottom of the central tube (17) and is arranged opposite to the lifting plate (9). The lifting plate (9) pushes the valve core rod (18) to move so that the central tube (17) switches between the closed state and the open state. The upper end of the central tube (17) of the upper power-off mechanism (6) is fixedly connected with a cooling tube (20) located above the protective tube (3). The cooling tube (20) is in communication with the coolant storage tank and an electromagnetic flow valve (21) is fixedly connected at the connection point between the two. The lower end of the central tube (17) of the lower power-off mechanism (7) is fixedly connected with an exhaust pipe (22) located below the protective tube (3). The exhaust pipe (22) is in communication with the external atmosphere. A smoke sensor (23) is fixedly connected to the outlet position of the outer end of the exhaust pipe (22). The early warning system comprises a control module, wherein the input end of the control module is respectively connected to a temperature monitoring module and a smoke monitoring module, the input end of the temperature monitoring module is connected to a temperature sensor (24), and the input end of the smoke monitoring module is connected to a smoke sensor (23), the output end of the control module is respectively connected to an early warning module and a power-off cooling module, the output end of the early warning module is respectively connected to a display screen and a buzzer alarm light, and the two sets of electromagnetic coils (14) of the upper power-off mechanism (6) and the lower power-off mechanism (7) and the electromagnetic flow valve (21) are both connected to the output end of the power-off cooling module.

2. According to claim 1, a battery thermal runaway early warning and protection system based on a BMS system is characterized in that: The conductive sheet (12) comprises a U-shaped portion (1201) and a pair of arc-shaped portions (1203) fixed at both ends thereof, the outer end of the arc-shaped portion (1203) is fixedly connected to a horizontal portion (1204), the lower end of the U-shaped portion (1201) is fixedly connected to a columnar portion (1202), and the columnar portion (1202) is used to contact the electrode of the cylindrical battery core (4); the inner shell (2) is fixedly connected to a plurality of wiring mechanisms located between adjacent protective cylinders (3), the wiring mechanisms comprising a truncated cone cylinder (27), the truncated cone cylinder (27) A lap joint (28) is provided inside, and the horizontal portion (1204) of the adjacent conductive sheet (12) is inserted into the conical cylinder (27) and abuts against the lap joint (28). The upper end of the lap joint (28) is rotatably connected to a locking bolt (29) threadedly connected to the conical cylinder (27); the end cover (8) includes an external thread ring (801) threadedly connected to the inner wall of the protective cylinder (3) and a rotating disk (802) located on the inner side of the external thread ring (801) and rotatably connected thereto, and the lifting disk (9) is slidably connected to the rotating disk (802).

3. According to the battery thermal runaway early warning protection system based on the BMS system of claim 1, it is characterized in that: The guide groove (501) is a vertical groove opened on the inner wall of the installation sleeve (5); the vertical length of the guide groove (501) is greater than the vertical height of the cylindrical battery core (4); the protective tube (3) and the installation sleeve (5) are both cylindrical structures with openings at both ends, and both are made of insulating thermal conductive material, which is one of polystyrene, high thermal conductivity epoxy resin, and aluminum oxide.

4. According to the battery thermal runaway early warning protection system based on the BMS system of claim 1, it is characterized in that: The lifting plate (9) comprises a boss (901) that is slidably abutted against the inner wall of the protective tube (3); a sliding plate (903) is fixedly connected to the boss (901); the sliding plate (903) passes through the end cover (8) and is slidably connected to the end cover (8); and a dispersion hole (902) is provided on the boss (901) at a portion located outside the sliding plate (903).

5. According to the battery thermal runaway early warning protection system based on the BMS system of claim 1, it is characterized in that: A pair of guide rods (10) penetrating the lifting plate (9) are fixedly connected to the end cover (8), a first spring (11) located between the end cover (8) and the lifting plate (9) is sleeved on the guide rods (10), and a first electric telescopic rod (15) and a second electric telescopic rod (16) vertically arranged are fixedly connected to the inner wall of the protective tube (3).

6. The battery thermal runaway early warning and protection system based on the BMS system according to claim 1 is characterized in that: The central tube (17) is a vertical circular tube and is internally fixedly connected with a radial support rod with a circular cross section passing through the central tube. The valve core rod (18) is a round rod with an I-shaped cross section. The valve core rod (18) passes through the radial support rod and is slidably connected thereto. A second spring (19) is sleeved on the lower part of the valve core rod (18) and is in contact with the radial support rod. A ventilation hole with an inner diameter smaller than the upper diameter of the valve core rod (18) is provided on the side of the central tube (17) away from the radial support rod. The upper part of the valve core rod (18) covers the upper end of the ventilation hole under the action of the second spring (19).

7. A battery thermal runaway early warning and protection system based on a BMS system according to claim 2, characterized in that: The truncated cone cylinder (27) is a truncated cone structure, and a through cavity (2701) is provided at the lower part for the horizontal part (1204) to be inserted, and the overlapping piece (28) is slidably nested in the through cavity (2701).

8. The battery thermal runaway early warning and protection system based on the BMS system according to claim 2 is characterized in that: The housing (1) is a hollow box structure and is provided with a detachable top plate and bottom plate. The outer ends of a plurality of truncated cone cylinders (27) distributed up and down are threadedly connected with fixing bolts (30) that penetrate the top plate or the bottom plate.

9. The battery thermal runaway early warning and protection system based on the BMS system according to claim 1, characterized in that: The early warning system includes the following steps when working: Step 1: The temperature monitoring module monitors the temperature of each cylindrical battery cell (4) through a temperature sensor (24); the control module compares the operating temperature of the cylindrical battery cell (4) with an operating temperature threshold; when the operating temperature of at least one cylindrical battery cell (4) exceeds the normal operating temperature threshold, step 2 is executed; otherwise, no operation is performed; Step 2: The power-off cooling module controls the corresponding electromagnetic coil (14) and the electromagnetic flow valve (21) to power off the abnormal cylindrical battery cell (4) and inject a first dose of coolant into the protective tube (3) where the abnormal cylindrical battery cell (4) is located. At the same time, the power-off cooling module powers off the adjacent cylindrical battery cells (4) around the abnormal cylindrical battery cell (4), and issues a first-level warning through the warning module to remind users to pay attention to the abnormal cylindrical battery cell (4) and repair it in time, and then execute step 3; Step 3: when it is monitored that the temperature of the abnormal cylindrical battery core (4) continues to rise after the coolant is injected, step 4 is executed; when it is monitored that the temperature of the abnormal cylindrical battery core (4) gradually decreases to the ambient temperature, step 5 is executed; Step 4: The power-off cooling module controls the electromagnetic flow valve (21) and the corresponding electromagnetic coil (14) so ​​that the central tube (17) below the abnormal cylindrical battery cell (4) is connected to the exhaust pipe (22), and continuously injects coolant into the protective cylinder (3) where the abnormal cylindrical battery cell (4) is located; at the same time, through the same operation, a second dose of coolant is injected into the protective cylinder (3) of the adjacent cylindrical battery cells (4) around the abnormal cylindrical battery cell (4); in addition, a second-level warning is issued through the warning module to remind the user to always pay attention to the temperature of the abnormal cylindrical battery cell (4), and then execute step 6; Step 5: The power-off cooling module stops the injection of coolant by controlling the corresponding electromagnetic coil (14) and the electromagnetic flow valve (21), connects the adjacent cylindrical battery cells (4) around the abnormal cylindrical battery cell (4), records the position of the abnormal cylindrical battery cell (4), and then executes step 1; Step 6: When it is monitored that the temperature of the abnormal cylindrical battery cell (4) exceeds the thermal runaway temperature, step 7 is executed; when it is monitored that the temperature of the abnormal cylindrical battery cell (4) gradually decreases to the ambient temperature and the flue gas sensor (23) does not detect the presence of flue gas at the exhaust pipe (22), step 5 is executed; Step 7: continuously inject coolant into the protective tube (3) where the adjacent cylindrical battery cells (4) are located, and cut off the power supply to all other cylindrical battery cells (4). A three-level warning is issued through the warning module to remind users to stay away from the battery pack and keep a safe distance, and then execute step 8; Step eight, when the temperature of the abnormal cylindrical battery cell (4) gradually drops to the ambient temperature and no smoke is discharged from the exhaust pipe (22), the power-off cooling module stops the injection of coolant by controlling the electromagnetic flow valve (21), and issues a level 4 warning through the warning module to remind the user to stop using the battery pack and to perform timely maintenance.

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