314Ah lithium iron phosphate energy storage battery thermal runaway early warning method and suppression device

Abstract

The invention relates to a 314Ah lithium iron phosphate energy storage battery thermal runaway early warning method and suppression device, and belongs to the field of battery thermal runaway prevention and control, the 314Ah lithium iron phosphate energy storage battery thermal runaway early warning method comprises a box body, a module is arranged in the box body, and the module comprises a plurality of lithium iron phosphate energy storage batteries; a clamp is arranged on the module and comprises a left fixed baffle, a movable baffle, a connecting lead screw, a right fixed baffle and at least two nuts. The connecting screw rod penetrates through the left fixed baffle plate, the movable baffle plate and the right fixed baffle plate; the nuts are in threaded connection with two ends of the connecting screw rod; the movable baffle can move in the left-right direction. A pressure sensor is mounted between the movable baffle and the right fixed baffle; each lithium iron phosphate energy storage battery is provided with a temperature sensor, a voltage sensor and a dynamic impedance sensor; a liquid cooling plate is mounted on the surface of the module; and the box body is provided with a water mist spraying nozzle for spraying water mist to the module. According to the method and the device, thermal runaway can be early warned and handled.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermal runaway prevention and control of lithium batteries, and specifically relates to a thermal runaway early warning method and a suppression device for a 314Ah lithium iron phosphate energy storage battery. Background Art

[0002] Given the advantages of lithium iron phosphate batteries such as good thermal stability, high safety performance and low cost, lithium iron phosphate energy storage power stations are becoming more and more popular. With the continuous development of energy storage technology, energy storage batteries are moving towards larger sizes and higher energy density. Therefore, energy storage batteries represented by 314Ah lithium iron phosphate batteries are being put into use on a large scale. With the increase in energy density, the safety of lithium iron phosphate batteries and energy storage power stations is bound to face more severe challenges.

[0003] At present, the thermal runaway warning technology of lithium iron phosphate energy storage batteries mostly relies on external characteristic parameters of the battery such as voltage, surface temperature, and gas. The warning timeliness is poor and the accuracy is low, which makes it difficult to meet market demand. This is because the size of lithium iron phosphate energy storage batteries is large, and it is inaccurate to use the characteristic parameter of the surface temperature of lithium iron phosphate energy storage batteries as a condition for judging thermal runaway. Therefore, it is necessary to obtain the characteristic parameter of the internal temperature of lithium iron phosphate energy storage batteries to make the conditions for judging thermal runaway more accurate.

[0004] On the other hand, some experts and scholars have implanted temperature, gas, pressure and other sensors inside the battery to achieve early warning based on the internal parameters of the battery, but they face defects such as high cost and poor compatibility with the battery. How to judge the internal state of the battery based on the external characteristic parameters based on the correlation between the internal and external characteristic parameters of the battery, and finally propose an early and efficient warning technology for thermal runaway, has become a difficult problem to be solved by the academic and industrial circles. Summary of the invention

[0005] A 314Ah lithium iron phosphate energy storage battery thermal runaway early warning method and suppression device of the present invention can obtain the internal temperature change of the battery based on the external temperature result according to the correlation between the internal and external temperatures of the 314Ah lithium iron phosphate energy storage battery. At the same time, combined with external characteristic parameters such as open circuit voltage, expansion force, dynamic impedance, etc., according to the comprehensive analysis of multi-dimensional parameters, a four-level hierarchical early warning method for lithium iron phosphate energy storage batteries is proposed to improve the accuracy of thermal runaway early warning.

[0006] A 314Ah lithium iron phosphate energy storage battery thermal runaway suppression device of the present invention comprises a box body, wherein at least one module is arranged in the box body, and the module comprises a plurality of lithium iron phosphate energy storage batteries; a clamp is arranged on the module, and the clamp comprises: a left fixed baffle, a movable baffle, a connecting screw, a right fixed baffle and at least two nuts; the connecting screw passes through the left fixed baffle, the movable baffle and the right fixed baffle; the nuts are threadedly connected to both ends of the connecting screw; Observe a group of modules, and assume that the placement direction of each lithium iron phosphate energy storage battery in the module is the left-right direction; the axis direction of the connecting screw is along the left-right direction; The right side surface of the left fixed baffle contacts the left side surface of the module, the left side surface of the movable baffle contacts the right side surface of the module, and the right fixed baffle is located on the right side of the movable baffle; the movable baffle can move in the left and right directions; one of the nuts contacts the left side surface of the left fixed baffle, and the other nut abuts against the right side surface of the right fixed baffle; the movable baffle does not contact the right fixed baffle; a pressure sensor is installed between the movable baffle and the right fixed baffle; the movable baffle and the right fixed baffle jointly squeeze the pressure sensor; Each lithium iron phosphate energy storage battery is equipped with a temperature sensor for monitoring its surface temperature; each lithium iron phosphate energy storage battery is connected to a voltage sensor for monitoring the open circuit voltage of the lithium iron phosphate energy storage battery; each lithium iron phosphate energy storage battery is connected to a dynamic impedance sensor for monitoring the dynamic impedance of the lithium iron phosphate energy storage battery; the pressure sensor, voltage sensor, dynamic impedance sensor and temperature sensor are all electrically connected to the controller; the controller can issue graded warnings based on the monitoring data of the pressure sensor, voltage sensor, dynamic impedance sensor and temperature sensor; A liquid cooling plate is installed on the surface of the module; a fine water mist spray nozzle for spraying water mist on the module is installed on the box.

[0007] The box is equipped with an RGBLED lamp capable of emitting light of different colors; the RGBLED lamp is electrically connected to a controller and can reflect the warning level according to the light color of the RGBLED lamp; the box is also equipped with an audible alarm, which is electrically connected to the controller.

[0008] Different colors can be used to reflect different warning levels, and relevant operators can also make corresponding preparations for thermal runaway of lithium iron phosphate energy storage batteries in time according to the different colors.

[0009] Furthermore, a plurality of modules are installed in the box, and the fine water mist spray nozzles are arranged in one-to-one correspondence with the modules.

[0010] Different modules can be sprayed with water through different fine water mist spray nozzles. When thermal runaway occurs, different modules can be sprayed with water according to the modules that have thermal runaway, so as to reduce losses.

[0011] Furthermore, the pressure sensor, voltage sensor, dynamic impedance sensor and temperature sensor are all numbered, and the controller can obtain the position of the lithium iron phosphate energy storage battery according to the numbers.

[0012] The specific location of the thermal runaway lithium iron phosphate energy storage battery and the location of the module to which it belongs can be known, and the location where the thermal runaway occurs can be known more clearly.

[0013] Furthermore, a 314Ah lithium iron phosphate energy storage battery thermal runaway early warning method comprises the following steps: S1: The controller receives the voltage values ​​of the voltage sensors on all lithium iron phosphate energy storage batteries. If the open circuit voltage of the lithium iron phosphate energy storage battery exceeds the threshold value U, the controller controls the RGBLED display light and the alarm to issue a first-level warning; the lithium iron phosphate energy storage batteries whose voltage values ​​exceed the set threshold value U are marked as problematic batteries; S2: The controller also receives the pressure data of the pressure sensor at the module where the problem battery is located; the pressure data is recorded as the problem pressure data, and the controller issues a first-level warning signal: If the pressure change rate of one of the problem pressure data exceeds the set threshold value P, the controller controls the RGBLED display light and the alarm to give a secondary warning; If the pressure change rate of all problematic pressure data does not exceed the threshold value P, the controller maintains the first-level warning of the RGBLED display light and the alarm; S3: The controller also receives the temperature data monitored by the temperature sensor on the problem battery, and calculates the internal temperature of the problem battery according to the temperature data monitored by the temperature sensor on the problem battery; the formula is: T i = 1.1 T e +1.6 (1) In the formula, T i is the internal temperature of the lithium iron phosphate energy storage battery; T e The external temperature of the lithium iron phosphate energy storage battery monitored by the temperature sensor; Under the premise that the controller issues a secondary warning signal: If the controller detects that the internal temperature of the problematic battery exceeds the threshold value S, the controller controls the RGBLED display light and the alarm to give a three-level warning; If the controller detects that the internal temperature of the problematic battery does not exceed the threshold S, the second-level warning is maintained; S4: The controller also receives the dynamic impedance data monitored by the dynamic impedance sensor on the problematic battery. When the controller issues a level 3 warning signal: If the controller detects that the dynamic impedance monitored by the dynamic impedance sensor on the problem battery has decreased, the controller will issue a four-level warning signal, and the controller will control the RGBLED display light and the alarm to issue a four-level warning; If the controller detects that the dynamic impedance monitored by the dynamic impedance sensor on the problem battery has not decreased, the third-level warning will be maintained.

[0014] The first-level warning means: the controller controls the RGBLED display light to display blue, and the controller controls the alarm to sound an alarm; The meaning of the second-level warning is: the controller controls the RGBLED display light to display yellow, and the controller controls the alarm to sound an alarm, and the controller also controls the water pumps on all liquid cooling plates to work; The meaning of the third-level warning is: the controller controls the RGBLED display light to display orange, and the controller controls the alarm to sound an alarm; the controller controls the water pump connected to the corresponding fine water mist spray nozzle to work, the water pump pumps water to the fine water mist spray nozzle and sprays water mist to spray water mist to cool the corresponding module; The meaning of the fourth-level warning is: the controller controls the RGBLED display light to display red, and the controller controls the alarm to sound an alarm; the relevant personnel in the energy storage power station evacuate the energy storage power station, and the relevant personnel contact the fire department in time.

[0015] Beneficial effects:

[0016] The device and method can determine the thermal runaway warning level of the lithium iron phosphate energy storage battery by setting a threshold value based on the data monitored by the pressure sensor, voltage sensor, dynamic impedance sensor and temperature sensor on the lithium iron phosphate energy storage battery, and can promptly remind personnel through corresponding means and spontaneously suppress thermal runaway.

[0017] Through formula (1), the external temperature of the lithium iron phosphate energy storage battery is converted to reflect the internal temperature, and the internal temperature is used to reflect the triggering conditions of thermal runaway, which is more in line with the actual situation and more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the thermal runaway suppression device for lithium iron phosphate energy storage batteries; Figure 2 It is a schematic diagram of the structure after the module is connected to the fixture; Figure 3 This is a top view of the liquid cooling plate and module; Figure 4 This is the data graph of each sensor when a 1000W heating plate of the same size as the battery is used as an external heat source to trigger thermal runaway of the battery; Figure 5 This is a schematic diagram of the early warning process and corresponding countermeasures of this method.

[0019] 1. Box; 2. Liquid cooling plate; 3. Lithium iron phosphate energy storage battery; 4. Left fixed baffle; 5. Movable baffle; 6. Right fixed baffle; 7. Connecting screw; 8. Nut; 9. Pressure sensor; 10. Controller; 11. RGBLED display light; 12. Alarm; 13. Fine water mist spray nozzle. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Example 1: See Figure 1 , Figure 2 and Figure 3 , a 314Ah lithium iron phosphate energy storage battery thermal runaway suppression device, including a box 1. From a top view, the box 1 is a rectangle, and one side of the box 1 is in the X direction. From the X direction, multiple rows of 314Ah lithium iron phosphate energy storage batteries are installed inside the box 1. A row of 314Ah lithium iron phosphate energy storage batteries is a module. There are multiple modules in total, and the multiple modules are arranged in parallel along the X direction. From a module perspective, a module has multiple lithium iron phosphate energy storage batteries, and the multiple lithium iron phosphate energy storage batteries are arranged in parallel along the Y direction and are bound into a whole by a clamp, that is, the aforementioned module. From a top view, the Y direction is perpendicular to the X direction.

[0022] When viewed in the X direction, a liquid cooling plate 2 is placed between two adjacent modules, or a liquid cooling plate 2 is also placed between the modules at both ends of the X direction and the inner wall of the box in the X direction. The two surfaces of the liquid cooling plate 2 between the two modules along the X direction are in close contact with the corresponding surfaces of the two adjacent modules. Only one side of the two liquid cooling plates 2 at both ends of the X direction is in close contact with the corresponding module surface.

[0023] The liquid cooling plate belongs to the existing technology. It is a brass material with a hollow middle part. Cooling liquid (50% water + 50% ethylene glycol) flows inside. The outlet and inlet of the liquid cooling plate both pass through the box body. The water pump drives the coolant in the liquid cooling plate to continuously flow through the water pump to the liquid cooling plate, so that the coolant in the liquid cooling plate circulates to reduce the temperature of the module.

[0024] For any module, let one end of the module along the Y direction be end A and the other end be end B; let end A be Figure 2The left side of the perspective of this scheme, and the B end is the right side of the perspective of this scheme. The fixture includes a left fixed baffle 4, a movable baffle 5, a plurality of connecting screws 7, a right fixed baffle 6 and a plurality of nuts 8. The left fixed baffle 4 is located on the left side of the module, the movable baffle 5 is located on the right side of the module, and the right fixed baffle 6 is located on the right side of the movable baffle 5. A plurality of connecting screws 7 pass through the left fixed baffle 7, the movable baffle 5 and the right fixed baffle 6 at the same time, and the axis of the connecting screw 7 is along the Y direction. Looking at a connecting screw 7, every two nuts 8 are screwed on both ends of each connecting screw, one of the nuts 8 contacts the left side surface of the left fixed baffle 4, and the other nut 8 contacts the right side surface of the right fixed baffle 6. The left side surface of the module abuts against the right side surface of the left fixed baffle 4, and the right side surface of the module abuts against the left side surface of the movable baffle 5. When the module expands due to thermal runaway, it is limited by the nut 8 on the left side of the connecting screw 7, so the left end of the module cannot be displaced, and the right end of the module will cause the movable baffle 5 to move to the right.

[0025] The right side of the movable baffle 5 does not contact the left side surface of the right fixed baffle 6, and a placement cavity is left between the two. From the perspective of one module, a pressure sensor 9 is placed in the placement cavity. The side of the pressure sensor 9 close to the movable baffle 5 abuts against the movable baffle 5, and the side of the pressure sensor 9 away from the movable baffle 5 abuts against the left side surface of the right fixed baffle 6. From the perspective of multiple modules, each pressure sensor is squeezed by the movable baffle 5 and the right fixed baffle 6, and each pressure sensor has the same initial pre-pressure. When the module has thermal runaway, as mentioned above, the module will expand, and the B end of the module will push the movable baffle 5 to the right along the Y direction. The movable baffle 5 will then squeeze the pressure sensor 9, and the pressure sensor 9 will generate pressure data.

[0026] The pressure sensor 9 is electrically connected to the controller 10 through a wire. The pressure sensors 9 of multiple modules are connected to the same controller 10. The controller 10 calculates the change in the values ​​of all the pressure sensors 9 over time, that is, the pressure change rate can be calculated by derivation. Each pressure sensor 9 has a unique number, and the controller can determine which module the pressure sensor 9 belongs to based on the number of the pressure sensor 9.

[0027] Taking any module as an example, any lithium iron phosphate energy storage battery in the module is equipped with a voltage sensor (not shown), which is used to detect the change of the open circuit voltage of the lithium iron phosphate energy storage battery.

[0028] Any voltage sensor is electrically connected to the positive and negative electrodes of the corresponding lithium iron phosphate energy storage battery. The voltage sensor is a prior art, and its principle is: the resistance of the voltage sensor is much larger than the internal resistance of the lithium iron phosphate energy storage battery, so the voltage sensor monitors its own voltage, which can be approximately regarded as the open circuit voltage of the lithium iron phosphate energy storage battery. The voltage sensors of all modules are electrically connected to the aforementioned controller, and the controller 10 can receive the voltage data of all voltage sensors. Each voltage sensor has a unique number, and the controller can determine which lithium iron phosphate energy storage battery the voltage sensor is connected to based on the voltage sensor number, and can also determine which module the lithium iron phosphate energy storage battery belongs to.

[0029] Taking any module as an example, any lithium iron phosphate energy storage battery in the module is equipped with a dynamic impedance sensor (not shown), which is used to detect changes in the dynamic impedance of the battery.

[0030] Any dynamic impedance sensor is electrically connected to the positive and negative electrodes of the corresponding lithium iron phosphate energy storage battery. The dynamic impedance sensor is a prior art, which applies an excitation current to the lithium iron phosphate energy storage battery through its own power supply, thereby detecting the impedance of the lithium iron phosphate energy storage battery under the excitation current. In this embodiment, the excitation current application frequency is 1000Hz. The dynamic impedance sensors of all modules are electrically connected to the aforementioned controller, and the controller 10 can receive the dynamic impedance data of all dynamic impedance sensors.

[0031] Looking at any module, any lithium iron phosphate energy storage battery in the module is equipped with a temperature sensor on its outer surface to monitor the temperature of the outer surface of the lithium iron phosphate energy storage battery. The temperature sensor is set at the center of the large surface of each lithium iron phosphate energy storage battery to measure the surface temperature of the large surface of the lithium iron phosphate energy storage battery.

[0032] The temperature sensors of all modules are electrically connected to the aforementioned controller 10, and the controller can receive temperature data from all temperature sensors. Each temperature sensor has a unique number, and the controller 10 can determine which lithium iron phosphate energy storage battery the temperature sensor is connected to based on the temperature sensor number, and can also determine which module the temperature sensor belongs to.

[0033] The outer surface of the box 1 is fixedly mounted with an RGBLED display light 11 and an alarm 12, and both the RGBLED display light 11 and the alarm 12 are electrically connected to the aforementioned controller 10. In this embodiment, the RGBLED display light can emit four colors of light to indicate different levels of warning; the alarm 12 can generate a sound alarm while the RGBLED display light 11 emits a light alarm.

[0034] A plurality of fine water mist spray nozzles 13 are fixedly mounted on the surface of the box 1. The fine water mist spray nozzles are arranged one by one in correspondence with the modules, that is, assuming that there are N modules, there are N corresponding fine water mist spray nozzles 13. In a top view, each fine water mist spray nozzle 13 is located directly above the corresponding module and can spray water mist to the corresponding module. The water pump pumps water to the fine water mist spray nozzle 13, and the fine water mist spray nozzle 13 sprays the water after atomizing it, thereby achieving the above-mentioned purpose of spraying water mist on the module.

[0035] Example 2: See Figure 5 , a 314Ah lithium iron phosphate energy storage battery thermal runaway early warning method, comprising the following steps: S1: The controller receives the voltage values ​​of the voltage sensors on all lithium iron phosphate energy storage batteries. If the controller detects that the voltage values ​​of one or more voltage sensors exceed the set threshold value U, such as 0.003V, the controller sends a first-level warning signal, and the controller controls the RGBLED display light and the alarm to issue a first-level warning.

[0036] The meaning of the first-level warning is: the controller controls the RGBLED display light to display blue, and the controller controls the alarm to sound an alarm; the controller displays one or more voltage sensor numbers that exceed the threshold U on the display screen (the display screen is electrically connected to the controller), reminding the supervisor to find the corresponding lithium iron phosphate energy storage battery according to the voltage sensor number, and the supervisor observes the status of the corresponding lithium iron phosphate energy storage battery.

[0037] All lithium iron phosphate energy storage batteries whose voltage values ​​exceed a set threshold value U are marked as problematic batteries, and the number of problematic batteries is one or more.

[0038] S2: The controller also receives pressure data from a pressure sensor at the module where the problem battery is located; the pressure data is recorded as problem pressure data, because the problem battery is not only in one module, but may be in multiple modules, so the problem pressure data may not be one, but multiple; Under the premise that the controller issues a first-level warning signal: If the pressure change rate of one of the problem pressure data exceeds the set threshold value P, such as 5N / s, the controller will issue a secondary warning signal, and the controller will control the RGBLED display light and the alarm for secondary warning. The meaning of the secondary warning is: the controller controls the RGBLED display light to display yellow, and the controller controls the alarm to sound an alarm. The controller also controls the water pumps on all liquid cooling plates to work, so that the coolant inside the liquid cooling plate circulates and reduces the temperature of all lithium iron phosphate energy storage batteries.

[0039] If the pressure change rate of all problematic pressure data does not exceed the threshold value P, the controller maintains the first-level warning of the RGBLED display light and the alarm.

[0040] S3: The controller also receives the temperature data monitored by the temperature sensor on the problem battery, and calculates the internal temperature of the problem battery according to the temperature data monitored by the temperature sensor on the problem battery; the formula is: T i = 1.1 T e +1.6 (1) In the formula, T i is the internal temperature of the lithium iron phosphate energy storage battery; T e The external temperature of the lithium iron phosphate energy storage battery is monitored by the temperature sensor.

[0041] Under the premise that the controller issues a secondary warning signal: If the controller detects that the internal temperature of the problematic battery exceeds the threshold value S, such as 50°C, the controller will issue a three-level warning signal, and the controller will control the RGBLED display light and the alarm to issue a three-level warning. The meaning of the three-level warning is: the controller controls the RGBLED display light to display orange, and the controller controls the alarm to sound an alarm; the controller determines which module the lithium iron phosphate energy storage battery connected to the temperature sensor belongs to based on the number of the temperature sensor, and then the controller controls the water pump connected to the corresponding fine water mist spray nozzle to work, and the water pump pumps water to the fine water mist spray nozzle and sprays water mist to spray water mist to cool the corresponding module; the controller controls the water pumps connected to other fine water mist spray nozzles not to work, so other modules will not be sprayed with water mist, minimizing the loss of other modules.

[0042] If the controller detects that the internal temperature of the problematic battery does not exceed the threshold S, the second-level warning is maintained; S4: The controller also receives the dynamic impedance data monitored by the dynamic impedance sensor on the problematic battery. When the controller issues a level 3 warning signal: If the controller detects that the dynamic impedance monitored by the dynamic impedance sensor on the problem battery decreases, the controller will issue a four-level warning signal, and the controller will control the RGBLED display light and the alarm to issue a four-level warning.

[0043] The meaning of the fourth-level warning is: the controller controls the RGBLED display to display red, and the controller controls the alarm to sound an alarm; the controller controls the water pumps of all liquid cooling plates to continue to work, and the controller also controls the water pumps connected to all fine water mist spray nozzles to continue to work. Relevant personnel in the energy storage power station evacuate the energy storage power station, and relevant personnel contact the fire department in time.

[0044] If the controller detects that the dynamic impedance monitored by the dynamic impedance sensor on the problem battery has not decreased, the third-level warning will be maintained.

[0045] Example 3: Taking a 314Ah lithium iron phosphate energy storage battery with a 50% state of charge as an example, a 1000W heating plate of the same size as the battery is used as an external heat source to trigger thermal runaway of the battery. The data of the battery internal temperature converted by the voltage sensor, pressure sensor, and temperature sensor, and the data monitored by the dynamic impedance sensor are recorded in Figure 4 Displayed in.

[0046] Table 1 summarizes the time of each level of warning and the time corresponding to the opening of the safety valve and the occurrence of thermal runaway. As shown in the table, if the first-level warning signal can be discovered and issued in time, there is still 1690s before the occurrence of thermal runaway, which can buy enough time for thermal runaway disposal. In addition, the thermal runaway warning margins provided by the second, third, and fourth level warnings are 1571, 1432, and 1360s respectively.

[0047] Table 1 Characteristic time and warning time difference Level 1 warning Second level warning Level 3 warning Level 4 warning Safety valve open Thermal runaway occurs Time(s) 546 665 804 876 1184 2236 Time difference (s) 1690 1571 1432 1360 \ \ As can be seen from Table 1, the proposed thermal runaway warning method is based on estimating multiple parameters such as internal temperature, open circuit voltage, expansion force, and dynamic impedance. Through comprehensive analysis of multi-dimensional parameters, a warning signal is issued, and the purpose of estimating the internal temperature of the battery and then judging the internal state of the battery is achieved by monitoring the external characteristic parameters of the battery, which can effectively improve the accuracy of the battery thermal runaway warning technology. In addition, the proposed four-level thermal runaway warning is activated before the battery safety valve is opened. At this time, there is still a long time before the battery thermal runaway occurs, which can buy enough time for the control of thermal runaway. In addition, effective suppression measures can be taken for thermal runaway of energy storage batteries according to the warning level, thereby reducing the possibility of thermal runaway and its consequences, and improving the safety of energy storage batteries.

[0048] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A 314Ah lithium iron phosphate energy storage battery thermal runaway suppression device, characterized in that: It comprises a box body, in which at least one module is arranged, and the module comprises a plurality of lithium iron phosphate energy storage batteries; a fixture is arranged on the module, and the fixture comprises: a left fixed baffle, a movable baffle, a connecting screw, a right fixed baffle and at least two nuts; the connecting screw passes through the left fixed baffle, the movable baffle and the right fixed baffle; the nuts are threadedly connected to both ends of the connecting screw; Observe a group of modules, and assume that the placement direction of each lithium iron phosphate energy storage battery in the module is the left-right direction; the axis direction of the connecting screw is along the left-right direction; The right side surface of the left fixed baffle contacts the left side surface of the module, the left side surface of the movable baffle contacts the right side surface of the module, and the right fixed baffle is located on the right side of the movable baffle; the movable baffle can move in the left and right directions; one of the nuts contacts the left side surface of the left fixed baffle, and the other nut abuts against the right side surface of the right fixed baffle; the movable baffle does not contact the right fixed baffle; a pressure sensor is installed between the movable baffle and the right fixed baffle; the movable baffle and the right fixed baffle jointly squeeze the pressure sensor; Each lithium iron phosphate energy storage battery is equipped with a temperature sensor for monitoring its surface temperature; each lithium iron phosphate energy storage battery is connected to a voltage sensor for monitoring the open circuit voltage of the lithium iron phosphate energy storage battery; each lithium iron phosphate energy storage battery is connected to a dynamic impedance sensor for monitoring the dynamic impedance of the lithium iron phosphate energy storage battery; the pressure sensor, voltage sensor, dynamic impedance sensor and temperature sensor are all electrically connected to the controller; the controller can issue graded warnings based on the monitoring data of the pressure sensor, voltage sensor, dynamic impedance sensor and temperature sensor; A liquid cooling plate is installed on the surface of the module; a fine water mist spray nozzle for spraying water mist on the module is installed on the box.

2. A 314Ah lithium iron phosphate energy storage battery thermal runaway suppression device according to claim 1, characterized in that: The box is equipped with an RGBLED lamp capable of emitting light of different colors; the RGBLED lamp is electrically connected to a controller and can reflect the warning level according to the light color of the RGBLED lamp; the box is also equipped with an audible alarm, which is electrically connected to the controller.

3. A 314Ah lithium iron phosphate energy storage battery thermal runaway suppression device according to claim 1, characterized in that: A plurality of modules are installed in the box, and the fine water mist spray nozzles are arranged in one-to-one correspondence with the modules.

4. A 314Ah lithium iron phosphate energy storage battery thermal runaway suppression device according to claim 3, characterized in that: The pressure sensor, voltage sensor, dynamic impedance sensor and temperature sensor are all numbered, and the controller can obtain the position of the lithium iron phosphate energy storage battery according to the numbers.

5. A 314Ah lithium iron phosphate energy storage battery thermal runaway early warning method, comprising the following steps: S1: The controller receives the voltage values ​​of the voltage sensors on all lithium iron phosphate energy storage batteries. If the open circuit voltage of the lithium iron phosphate energy storage battery exceeds the threshold value U, the controller controls the RGBLED display light and the alarm to issue a first-level warning; the lithium iron phosphate energy storage batteries whose voltage values ​​exceed the set threshold value U are marked as problematic batteries; S2: The controller also receives the pressure data of the pressure sensor at the module where the problem battery is located; the pressure data is recorded as the problem pressure data, and the controller issues a first-level warning signal: If the pressure change rate of one of the problem pressure data exceeds the set threshold value P, the controller controls the RGBLED display light and the alarm to give a secondary warning; If the pressure change rate of all problematic pressure data does not exceed the threshold value P, the controller maintains the first-level warning of the RGBLED display light and the alarm; S3: The controller also receives the temperature data monitored by the temperature sensor on the problem battery, and calculates the internal temperature of the problem battery according to the temperature data monitored by the temperature sensor on the problem battery; the formula is: T i = 1.1 T e +1.6 （1） In the formula, T i is the internal temperature of the lithium iron phosphate energy storage battery; T e The external temperature of the lithium iron phosphate energy storage battery monitored by the temperature sensor; Under the premise that the controller issues a secondary warning signal: If the controller detects that the internal temperature of the problematic battery exceeds the threshold value S, the controller controls the RGBLED display light and the alarm to give a three-level warning; If the controller detects that the internal temperature of the problematic battery does not exceed the threshold S, the second-level warning is maintained; S4: The controller also receives the dynamic impedance data monitored by the dynamic impedance sensor on the problematic battery. When the controller issues a level 3 warning signal: If the controller detects that the dynamic impedance monitored by the dynamic impedance sensor on the problem battery has decreased, the controller will issue a four-level warning signal, and the controller will control the RGBLED display light and the alarm to issue a four-level warning; If the controller detects that the dynamic impedance monitored by the dynamic impedance sensor on the problem battery has not decreased, the third-level warning will be maintained.

6. A 314Ah lithium iron phosphate energy storage battery thermal runaway early warning method according to claim 5, characterized in that: The first-level warning means: the controller controls the RGBLED display light to display blue, and the controller controls the alarm to sound an alarm; The meaning of the second-level warning is: the controller controls the RGBLED display light to display yellow, and the controller controls the alarm to sound an alarm, and the controller also controls the water pumps on all liquid cooling plates to work; The meaning of the third-level warning is: the controller controls the RGBLED display light to display orange, and the controller controls the alarm to sound an alarm; the controller controls the water pump connected to the corresponding fine water mist spray nozzle to work, the water pump pumps water to the fine water mist spray nozzle and sprays water mist to spray water mist to cool the corresponding module; The meaning of the fourth-level warning is: the controller controls the RGBLED display light to display red, and the controller controls the alarm to sound an alarm; the relevant personnel in the energy storage power station evacuate the energy storage power station, and the relevant personnel contact the fire department in time.

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