New energy power battery thermal runaway monitoring and processing system and method

Abstract

The invention discloses a new energy power battery thermal runaway monitoring and processing system and method, the system comprises a battery management system BMS, and the battery management system BMS outputs a control signal to a vehicle control unit for early warning control after monitoring that a battery is in a thermal runaway state; the system further comprises a plurality of thermal runaway monitoring modules which are mutually independent. Each thermal runaway monitoring module independently collects data corresponding to characterization or prediction thermal runaway, the output end of each thermal runaway monitoring module is connected to the BMS, and the BMS judges whether the thermal runaway state is in or not based on the monitoring data collected by the multiple thermal runaway monitoring modules independent of one another. According to the method, the accuracy of monitoring the thermal runaway state is improved in a multi-channel detection mode, and multiple control strategies are further carried out based on accurate thermal runaway monitoring so as to delay or reduce subsequent fire sites of thermal runaway.

Description

Technical Field

[0001] The present invention relates to the technical field of battery pack thermal runaway, and in particular to a new energy power battery thermal runaway monitoring and processing system and method. Background Art

[0002] At present, pure electric vehicles have become the mainstream of new energy vehicles, but the safety of electric vehicles has always been controversial in the automobile market. Customers are full of concerns about the safety of their new energy power batteries, especially when the car collides, the power battery assembly is bumped or high temperature occurs. If the vehicle does not promptly remind passengers that the power battery has thermal runaway, the possibility of passengers' safe escape is greatly reduced. In addition, the existing battery pack, if the power assembly, does not have an effective method to limit thermal diffusion, it only reminds passengers. If the power battery triggers thermal diffusion, the diffusion speed is fast and the fire speed is fast, there is a huge safety hazard. As a key safety control system of the whole vehicle, the safety strategy and method of the thermal diffusion system will greatly affect the safety and reliability of the whole vehicle.

[0003] For example, a power battery thermal runaway full-time monitoring system, method and new energy vehicle with patent application number 202110221494.6 includes: a collection device and a battery management system connected thereto; the collection device is used to: perform timed self-wake-up after the battery management system is in a dormant state; and after self-wake-up, collect the real-time temperature and real-time voltage of each single cell of the power battery; then compare the real-time temperature and real-time voltage of each single cell with their respective corresponding preset thresholds; if the real-time voltage of a single cell is less than the corresponding preset voltage threshold, and / or, if the real-time temperature of a single cell is greater than the corresponding preset temperature threshold, wake up the battery management system; the battery management system is used to: after being awakened by the collection device, perform thermal runaway monitoring based on the temperature rise rate and voltage drop rate of each single cell of the power battery.

[0004] Although the above patent provides a thermal runaway monitoring solution, it only uses a single-channel monitoring strategy to monitor thermal runaway. If the thermal runaway judgment of the channel is abnormal due to missing data or abnormal monitoring of some data, it will lead to the inability to accurately identify thermal runaway, and then the subsequent thermal runaway processing work cannot be carried out, resulting in the occurrence of safety accidents. This single thermal runaway monitoring solution in the prior art cannot meet the reliability requirements. At the same time, after monitoring a reliable thermal runaway state, how to delay the fire after thermal runaway or even avoid or reduce the thermal runaway fire is actually crucial to the timely escape of passengers in the car. The prior art still has shortcomings in this area. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a new energy power battery thermal runaway monitoring and processing system and method, which improves the accuracy of monitoring the thermal runaway state through a multi-channel detection method, and further implements a variety of control strategies based on accurate thermal runaway monitoring to delay or reduce the subsequent fire scene of thermal runaway.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a new energy power battery thermal runaway monitoring and processing system, including a battery management system BMS, and the battery management system BMS outputs a control signal to the vehicle controller for early warning control after monitoring that the battery is in a thermal runaway state; the system also includes multiple independent thermal runaway monitoring modules; each thermal runaway monitoring module independently collects data corresponding to characterization or prediction of thermal runaway, and its output end is connected to the BMS, and the BMS determines whether it is in a thermal runaway state based on the monitoring data collected by multiple independent thermal runaway monitoring modules.

[0007] The system also includes a smoke sensor and a fire extinguishing system, and the battery management system BMS is connected to the smoke sensor and the fire extinguishing system respectively; the BMS drives and controls the fire extinguishing system to cool the battery pack according to the signal of the smoke sensor.

[0008] The fire extinguishing system includes a liquid nitrogen high-pressure tank, an outlet solenoid valve, and a nozzle arranged in a battery pack, wherein the nozzle has nozzles at multiple positions in the battery pack; the battery management system BMS controls the outlet solenoid valve of the fire extinguishing system.

[0009] A pressure relief valve is provided on the box of the power battery pack, and an air pressure sensor is provided in the battery pack. The air pressure sensor is used to detect the gas pressure value in the battery pack, and the output end of the air pressure sensor is connected to the battery management system BMS. The output end of the battery management system is connected to the pressure relief valve, which is used to control the operation of the pressure relief valve according to the internal pressure value of the battery pack after the thermal runaway warning.

[0010] A pressure sensing device is provided in the liquid nitrogen high-pressure tank, and an output end of the pressure sensing device is connected to a battery management system BMS. The battery management system BMS is used to monitor the pressure in the tank to issue a corresponding maintenance and rehydration reminder.

[0011] A monitoring and early warning method of a new energy power battery thermal runaway monitoring and early warning system, comprising:

[0012] Thermal runaway monitoring data is collected through multiple channels, and thermal runaway judgment is performed based on the thermal runaway monitoring data of each channel to obtain the thermal runaway judgment result corresponding to the thermal runaway data of each channel; if there are two or more thermal runaway judgment results, it is judged that the battery is in a thermal runaway state at this time. At this time, the battery BMS feeds back the vehicle ACU to limit the vehicle power and unlock the vehicle, and sends out a corresponding early warning reminder signal.

[0013] The thermal runaway data collected by each channel is compared with the corresponding pre-designed thermal runaway conditions. When the thermal runaway data meets the corresponding thermal runaway conditions and reaches the set time threshold, the judgment result of the channel is that the battery is in a thermal runaway state; in the thermal runaway state, the thermal runaway data of each channel is collected in real time and a corresponding judgment is made. When the thermal runaway judgment result is reduced from two or more channels to one or none, the BMS feeds back a control signal to the ACU, causing it to cancel the vehicle ACU power restriction after a delay of the set time.

[0014] When it is judged to be in a thermal runaway state, the BMS monitors the smoke signal in real time through the smoke sensor. When the smoke signal is detected, it is judged that the thermal runaway state has caused a fire or there is a possibility of fire and loss of control. At this time, the BMS drives the fire extinguishing system to cool down the battery pack. If no smoke signal is detected by the smoke sensor, the BMS sends a power-off command, the entire vehicle enters the power-off state, and drives and controls the on-board alarm system to send an alarm signal to the driver and passengers, and keeps the doors unlocked.

[0015] When the fire extinguishing system is started, the temperature is controlled through the outlet solenoid valve of the liquid nitrogen tank, and the opening size of the outlet solenoid valve is controlled based on the detected temperature of the battery pack.

[0016] When the fire extinguishing system starts working, the outlet solenoid valve opens to the set opening width, and then the battery pack temperature is detected. When the temperature at any position in the battery pack is greater than the set temperature threshold, the outlet solenoid valve is controlled to open fully to enable liquid nitrogen to quickly cool the battery pack.

[0017] The advantages of the present invention are: through the multi-condition prejudgment thermal runaway system, the thermal runaway signal is confirmed in advance, and early warning, vehicle power limitation and vehicle door unlocking are performed. When the thermal runaway signal is confirmed by the BMS, the BMS continues to confirm the smoke sensor signal. When the smoke sensor signal is clear, the fire extinguishing system cooperates with the fire extinguishing device to half-open the solenoid valve to reduce the heat diffusion and fire caused by thermal runaway. When the BMS confirms that the module temperature or the whole package temperature is greater than or equal to 100°C during thermal runaway, the fire extinguishing system cooperates with the fire extinguishing device to fully open the solenoid valve, thereby effectively curbing the thermal diffusion state of the battery cell, reducing or eliminating the thermal diffusion state of the battery cell, and effectively reducing the risk of fire and explosion caused by thermal diffusion of the vehicle, while also ensuring the escape time of passengers and reducing the safety risks of passengers. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The following is a brief description of the contents expressed in the drawings of the present invention and the symbols in the drawings:

[0019] Figure 1 It is a schematic diagram of the structure of the processing system of the present invention;

[0020] Figure 2 This is a control flow chart under thermal runaway monitoring of the present invention;

[0021] Figure 3 It is a solenoid valve control flow chart of the fire extinguishing system of the present invention;

[0022] Figure 4 This is a thermal runaway judgment flow chart of channel 1 of the present invention;

[0023] Figure 5 This is a thermal runaway judgment flow chart of channel 2 of the present invention;

[0024] Figure 6 This is a thermal runaway judgment flow chart of channel three of the present invention;

[0025] Figure 7 This is a thermal runaway judgment flow chart of channel 4 of the present invention;

[0026] Figure 8 This is a thermal runaway judgment flow chart for channel five of the present invention.

[0027] The markings in the above figures are: 1. Smoke sensor; 2. Outlet solenoid valve; 3. Liquid nitrogen replenishment port; 4. Pressure relief solenoid valve; 5. Nozzle. DETAILED DESCRIPTION

[0028] The specific implementation of the present invention will be further explained in detail below by describing the optimal embodiment with reference to the accompanying drawings.

[0029] The purpose of the present invention is to predict the thermal runaway system through multiple conditions, confirm the thermal runaway signal in advance, and give early warning. When the thermal runaway signal is confirmed, the fire extinguishing system cooperates with the fire extinguishing device to reduce the heat diffusion and fire caused by thermal runaway, effectively reducing the risk of fire and explosion caused by thermal diffusion in the vehicle, while also ensuring the escape time of passengers and reducing the safety risks of passengers.

[0030] like Figure 1As shown, a new energy power battery thermal runaway monitoring and processing system includes a battery management system BMS. After monitoring that the battery is in a thermal runaway state, the battery management system BMS outputs a control signal to the vehicle controller for early warning control; the system also includes multiple independent thermal runaway monitoring modules; each thermal runaway monitoring module independently collects data corresponding to the characterization or prediction of thermal runaway, and its output end is connected to the BMS. The BMS determines whether it is in a thermal runaway state based on the monitoring data collected by multiple independent thermal runaway monitoring modules. Each thermal runaway monitoring module is used to monitor a type of data that can be used to judge thermal runaway, and then the BMS determines whether it is in thermal runaway based on each thermal runaway data. When the thermal runaway state reaches two or more, it is determined that it is in a thermal runaway state at this time, and then a warning alarm is issued. This method can accurately and reliably determine thermal runaway and avoid misidentification caused by omissions or faults. Because when it is indeed in a thermal runaway state, multiple channels should determine the thermal runaway state. If some of them cannot determine thermal runaway due to faults caused by collisions, but since this solution has multiple channels, only any two channels can determine thermal runaway, then thermal runaway processing is performed, which improves reliability. The possibility of all channels failing and unable to identify thermal runaway is relatively low. Therefore, this method can greatly improve the accuracy of thermal runaway identification, thereby providing the basic conditions for subsequent thermal runaway processing and user escape.

[0031] The system further includes a smoke sensor and a fire extinguishing system, and the battery management system BMS is connected to the smoke sensor and the fire extinguishing system respectively; the BMS drives and controls the fire extinguishing system to cool the battery pack according to the signal of the smoke sensor. The fire extinguishing system includes a liquid nitrogen high-pressure tank, an outlet solenoid valve and a nozzle arranged in the battery pack, and the nozzle has nozzles at multiple positions in the battery pack; the battery management system BMS controls the outlet solenoid valve of the fire extinguishing system. In order to facilitate the replenishment of liquid nitrogen, a liquid nitrogen refilling port is provided on the battery pack body, through which the liquid nitrogen in the liquid nitrogen high-pressure tank can be replenished.

[0032] A pressure relief valve is provided on the box of the power battery pack, and a gas pressure sensor is provided inside the battery pack. The gas pressure sensor is used to detect the gas pressure value inside the battery pack, and its output end is connected to the battery management system BMS; the output end of the battery management system is connected to the pressure relief valve, which is used to control the operation of the pressure relief valve according to the internal pressure value of the battery pack after the thermal runaway warning. In the thermal runaway state, the safety risk caused by the increase in internal pressure of the battery pack due to the spraying of liquid nitrogen can be controlled by the pressure relief valve.

[0033] A pressure sensing device is provided in the liquid nitrogen high-pressure tank, and its output end is connected to the battery management system BMS. The battery management system BMS is used to monitor the pressure in the tank to issue corresponding maintenance and rehydration reminders. The pressure in the hydraulic tank can be monitored. When the pressure is insufficient, it indicates that the liquid nitrogen content is insufficient. At this time, the rehydration can be controlled through the liquid nitrogen rehydration port.

[0034] The monitoring and early warning method based on the above-mentioned new energy power battery thermal runaway monitoring and early warning system includes the following:

[0035] Thermal runaway monitoring data is collected through multiple channels, and thermal runaway judgment is performed based on the thermal runaway monitoring data of each channel to obtain the thermal runaway judgment result corresponding to the thermal runaway data of each channel; if there are two or more thermal runaway judgment results, it is judged that the battery is in a thermal runaway state at this time. At this time, the battery BMS feeds back the vehicle ACU to limit the vehicle power and unlock the vehicle, and sends out a corresponding early warning reminder signal.

[0036] Multi-channel thermal runaway monitoring and judgment obtain thermal runaway results, such as Figure 4-8 As shown, it is a flow chart of thermal runaway monitoring of five channels;

[0037] Channel 1: When the minimum voltage Vmin of the battery cell is less than 2.0V for 300ms and the maximum temperature Tmax in the battery cell is greater than 68 degrees Celsius for 2000ms; or when the minimum voltage Vmin of the battery cell is less than 2.0V for 300ms and the temperature difference between the maximum temperature and the minimum temperature in the battery cell is greater than 30 degrees Celsius for 2000ms; or when the minimum voltage Vmin of the battery cell is less than 2.0V for 300ms and the battery temperature rises too fast, reaching 3 degrees Celsius per second, the judgment result monitored by this channel is that thermal runaway has occurred.

[0038] Channel 2: When a collection line fault is detected and the maximum temperature Tmax of the battery cell in the battery pack is greater than 68 degrees Celsius and lasts for 2000ms; or the collection line fault is detected and the temperature rises too quickly to 3 degrees Celsius per second and lasts for 2000ms; or the collection line fault is detected and the temperature difference between the maximum temperature and the minimum temperature in the battery cell is greater than 30 degrees Celsius and lasts for 2000ms; if any of the following conditions is met, the judgment result monitored by this channel is that thermal runaway has occurred.

[0039] Channel 3: The collected cell data is not updated for 2000ms and the maximum temperature Tmax in the cell is greater than 68 degrees Celsius and lasts for 2000ms; or the collected cell data is not updated for 2000ms and the temperature rises too quickly to 3 degrees Celsius per second and lasts for 2000ms; or the collected cell data is not updated for 2000ms and the temperature difference between the maximum temperature and the minimum temperature in the battery cell is greater than 30 degrees Celsius and lasts for 2000ms; if any one of the conditions is met, it is judged that the judgment result monitored by this channel is thermal runaway.

[0040] Channel 4: An insulation fault is detected and the maximum temperature Tmax in the largest cell is greater than 68 degrees Celsius and lasts for 2000ms; or an insulation fault is detected and the temperature difference between the maximum temperature and the minimum temperature in the battery cell is greater than 30 degrees Celsius and lasts for 2000ms; if any of the conditions is met, the judgment result monitored by this channel is that thermal runaway has occurred.

[0041] Channel 5: The temperature rise is detected to be too fast, reaching 3 degrees Celsius per second and lasting for 2000ms, and the maximum temperature Tmax in the battery cell is greater than 68 degrees Celsius and lasting for 2000ms; or the temperature rise is detected to be too fast, reaching 3 degrees Celsius per second and lasting for 2000ms, and the temperature difference between the maximum temperature and the minimum temperature in the battery cell is greater than 30 degrees Celsius and lasting for 2000ms; when any one of the conditions is met, the judgment result monitored by this channel is that thermal runaway has occurred.

[0042] If the results of two of the five channels are in a thermal runaway state, it is determined that the battery pack is in a thermal runaway state and the corresponding control strategy is executed.

[0043] The thermal runaway data collected by each channel is compared with the corresponding pre-designed thermal runaway conditions. When the thermal runaway data meets the corresponding thermal runaway conditions and reaches the set time threshold, the judgment result of the channel is that the battery is in a thermal runaway state; in the thermal runaway state, the thermal runaway data of each channel is collected in real time and a corresponding judgment is made. When the thermal runaway judgment result is reduced from two or more channels to one or none, the BMS feeds back a control signal to the ACU, causing it to cancel the vehicle ACU power restriction after a delay of the set time.

[0044] When it is judged to be in a thermal runaway state, the BMS monitors the smoke signal in real time through the smoke sensor. When the smoke signal is detected, it is judged that the thermal runaway state has caused a fire or there is a possibility of fire and loss of control. At this time, the BMS drives the fire extinguishing system to cool down the battery pack. If no smoke signal is detected by the smoke sensor, the BMS sends a power-off command, the entire vehicle enters the power-off state, and drives and controls the on-board alarm system to send an alarm signal to the driver and passengers, and keeps the doors unlocked.

[0045] When the fire extinguishing system is started, the temperature is controlled through the outlet solenoid valve of the liquid nitrogen tank, and the opening size of the outlet solenoid valve is controlled based on the detected temperature of the battery pack.

[0046] When the fire extinguishing system starts working, the outlet solenoid valve opens to the set opening width, and then the battery pack temperature is detected. When the temperature at any position in the battery pack is greater than the set temperature threshold, the outlet solenoid valve is controlled to open fully to achieve rapid cooling of the battery pack by liquid nitrogen. When the fire extinguishing system is started, the outlet solenoid valve is opened to a half-open state by default, and then the temperature of the battery module is detected. When the temperature requirement of 100 degrees Celsius is met, the solenoid valve is opened to full open. The outlet solenoid valve is the outlet solenoid valve of the liquid nitrogen tank. The solenoid valve can control the spraying speed of liquid nitrogen, thereby cooling the thermal runaway in the battery pack and improving safety. The outlet solenoid valve is set at the outlet of the liquid nitrogen tank, and then its output is extended to various positions in the battery pack through a pipeline. A nozzle is set on the pipeline, so that liquid nitrogen can be sprayed at different positions in the battery pack through multiple nozzles, thereby achieving a cooling effect and minimizing the fire caused by the rapid rise in temperature. At the same time, the gas pressure in the battery pack will increase due to the cooling and vaporization of liquid nitrogen. The pressure is monitored by the pressure sensor. When the pressure is greater than the set threshold, the pressure relief valve is driven to open to release the gas pressure in the battery pack. At the same time, since nitrogen is also an inert gas, the nitrogen in the battery pack also plays a certain role in reducing combustion. The liquid nitrogen tank is a high-pressure tank. When the internal pressure is insufficient, it means that liquid nitrogen needs to be replenished. Therefore, a pressure sensor is set to detect the pressure in the tank, and then the nitrogen replenishment of the liquid nitrogen tank is controlled through monitoring to maintain sufficient nitrogen in the vehicle. When the pressure in the nitrogen tank is detected to be insufficient, the BMS issues a reminder through the on-board instrument, display, etc., so as to remind the user to repair or replenish liquid nitrogen in time, so as to ensure sufficient liquid nitrogen.

[0047] The above solution is applied to the power battery assembly. Through the multi-condition pre-judgment thermal runaway system, the thermal runaway signal is confirmed in advance, and early warning, vehicle power limitation and vehicle door unlocking are performed. When the thermal runaway signal is confirmed by the BMS, the BMS continues to confirm the smoke sensor signal. When the smoke sensor signal is clear, the fire extinguishing system cooperates with the fire extinguishing device to half-open the solenoid valve to reduce the heat diffusion and fire caused by thermal runaway. When the BMS confirms that the module temperature or the whole package temperature is greater than or equal to 100°C during thermal runaway, the fire extinguishing system cooperates with the fire extinguishing device to fully open the solenoid valve, thereby effectively curbing the thermal diffusion state of the battery cell, reducing or eliminating the thermal diffusion state of the battery cell, and effectively reducing the risk of fire and explosion caused by thermal diffusion of the vehicle, while also ensuring the escape time of passengers and reducing the safety risks of passengers.

[0048] Based on the multi-condition pre-judgment thermal runaway system, based on the analysis of multiple conditions such as single cell voltage threshold, temperature threshold, temperature rise rate, acquisition fault, temperature difference threshold, cell single cell data, insulation fault, etc., if two or more of the judgment conditions are met and the time limit is reached, the BMS will pre-judgment that the power battery assembly has reached the thermal runaway condition, and the BMS will feedback the vehicle ACU to limit the vehicle power and unlock the vehicle. If the signal fault recovers by itself and the conditions do not meet the triggering thermal runaway conditions, the BMS feedback ACU signal will be maintained for one minute, and the vehicle ACU will cancel the vehicle power restriction.

[0049] If the multi-conditional prediction of thermal runaway system signal is confirmed, BMS will read the smoke sensor alarm signal at the same time. If there is no alarm signal, the fire extinguishing system will not be activated. If the smoke alarm transmits an alarm signal, BMS will send a signal to the fire extinguishing system. At the same time, BMS will feedback the ACU heat diffusion signal, the high voltage command, and the vehicle door unlocking signal.

[0050] When executing the fire extinguishing system, BMS transmits a half-open solenoid valve signal to the fire extinguishing system signal transceiver device. After receiving the signal, the device transmits it to the solenoid valve, and the solenoid valve is half open. The liquid nitrogen in the high-pressure tank for storing liquid nitrogen is sprayed in a mist form through the nozzle of the output pipeline. When BMS detects that the temperature of the entire package or module is greater than or equal to 100°C, BMS transmits a full-open signal to the fire extinguishing system signal receiver device. After receiving the signal, the device transmits it to the solenoid valve, and the solenoid valve is fully opened. The liquid nitrogen in the high-pressure tank for storing liquid nitrogen is sprayed in a mist form through the nozzle of the output pipeline. Figure 1 As shown, the fire extinguishing system device is composed of a liquid nitrogen high-pressure tank, a solenoid valve, a fire extinguishing signal receiver, pipelines, a nozzle, etc.

[0051] The purpose of the present invention is to propose a new energy power battery prediction system, a thermal runaway fire extinguishing system and a device to solve the problems in the above-mentioned background technology.

[0052] The present invention proposes a new energy power battery prediction system, a thermal runaway fire extinguishing system and a device, which are applied to a new energy vehicle powertrain. The method includes:

[0053] 1. Add a multi-condition thermal runaway prediction system to the BMS to judge thermal runaway in advance and improve customer safety;

[0054] 2. Add multiple prediction conditions to the thermal runaway prediction system to improve the prediction accuracy;

[0055] 3. Add a smoke sensor to further confirm whether the powertrain has a fire or loss of control in a thermal runaway state, so as to confirm whether to enter the fire extinguishing system to curb the thermal runaway state or heat diffusion state;

[0056] 4. Add a fire extinguishing system. When the fire extinguishing system is activated, the door locks of the entire vehicle and the high pressure of the entire vehicle are released at the same time, helping to improve the safety of passengers and the escape time;

[0057] 5. Add fire extinguishing devices to reduce the transition of power batteries from thermal runaway to thermal diffusion, which can effectively reduce the probability of fire in new energy vehicles and greatly reduce the safety risks of passengers;

[0058] 6. Add a fire extinguishing device maintenance system to ensure the effectiveness and sustainability of the fire extinguishing device;

[0059] The new energy power battery prediction system, thermal runaway fire extinguishing system and device proposed in the present invention have the following beneficial effects:

[0060] Through the multi-conditional prediction of thermal runaway system, the thermal runaway signal is confirmed in advance, and early warning, vehicle power limitation and vehicle door unlocking are carried out. When the thermal runaway signal is confirmed by BMS, BMS continues to confirm the smoke sensor signal. When the smoke sensor signal is clear, the fire extinguishing system cooperates with the fire extinguishing device to half-open the solenoid valve to reduce the heat diffusion and fire caused by thermal runaway. When the BMS confirms that the module temperature or the whole package temperature is greater than or equal to 100°C during thermal runaway, the fire extinguishing system cooperates with the fire extinguishing device to fully open the solenoid valve, thereby effectively curbing the thermal diffusion state of the battery cell, reducing or eliminating the thermal diffusion state of the battery cell, and effectively reducing the risk of fire and explosion caused by thermal diffusion of the vehicle, while also ensuring the escape time of passengers and reducing the safety risks of passengers.

[0061] In addition, the new energy power battery prediction system, thermal runaway fire extinguishing system and device provided by the present invention may also have the following technical features:

[0062] Furthermore, the BMS comprehensively analyzes the multi-condition prediction system to determine whether thermal runaway occurs in the vehicle, and the steps specifically include:

[0063] If two or more of the predicted thermal runaway signals are reliable, it is determined that the entire vehicle has collided.

[0064] Furthermore, if the predicted system thermal runaway signal is one, the system does not make a judgment. If the predicted system thermal runaway signal is two judgment conditions or more than two conditions and the time limit is reached, the BMS pre-determines that the power battery assembly has reached the thermal runaway condition, and the BMS feeds back the vehicle ACU to limit the vehicle power and unlock the vehicle. If the signal fault recovers after the conditions do not meet the triggering thermal runaway conditions, the BMS feeds back the ACU signal for one minute and cancels the vehicle ACU limiting the vehicle power.

[0065] If the thermal runaway is predicted successfully and the thermal runaway conditions are met, the steps to enter the fire extinguishing system specifically include:

[0066] As in the fire extinguishing system, the BMS detects the smoke sensor alarm signal to further confirm whether the powertrain has a thermal runaway state and whether a fire or a loss of control has occurred.

[0067] Furthermore, after the step of analyzing the alarm signal of the smoke sensor according to the BMS to determine whether thermal runaway occurs in the vehicle, the method further includes:

[0068] If the smoke sensor does not transmit an alarm signal to the BMS, the BMS determines that the power battery assembly does not need to be extinguished by the fire extinguishing system, and only executes the power-off command and sends a heat diffusion signal to the ACU. The vehicle ACU lights up the fault light to alert the driver and passengers, and simultaneously unlocks the vehicle door locks to allow passengers to escape safely.

[0069] Furthermore, if the smoke sensor transmits an alarm signal to the BMS, the steps for the BMS to determine that the power battery assembly needs to be extinguished by the fire extinguishing system include:

[0070] For the intervention of the fire extinguishing system, the BMS transmits a signal to the signal transceiver device of the fire extinguishing system through a hard line. When the signal transceiver device receives the signal input, it sends a half-open signal instruction to make the output solenoid valve enter a half-open state, allowing high-pressure liquid nitrogen to enter the output pipeline and spray liquid nitrogen through the pressure nozzle to extinguish the fire and prevent the thermal runaway state from entering the thermal diffusion state.

[0071] When the fire extinguishing system is intervened, when the temperature of the BMS detection assembly is greater than or equal to 100°C or the temperature of the battery cell is greater than or equal to 100°C, and one of the conditions is met, a full-open signal command is sent to transmit the signal to the fire extinguishing system signal transceiver device through a hard wire. When the signal input is received, a full-open signal command is sent to make the output solenoid valve enter the full-open state, allowing the high-pressure liquid nitrogen to accelerate into the output pipeline. The pressure nozzle changes the spray state due to the pressure to spray liquid nitrogen in a thick line and mist shape, thereby quickly extinguishing the fire and preventing the heat diffusion state caused by thermal runaway.

[0072] The linkage device required for the fire extinguishing system is controlled by the fire extinguishing system in the BMS, and the signal is transmitted and received through the signal transceiver. The signal transceiver sends and receives signals through hard wires, and the signal is transmitted between the BMS, the output solenoid valve and the input solenoid valve. The output speed of the high-pressure liquid nitrogen tank is controlled by the output solenoid valve, and the input solenoid valve monitors the pressure in the high-pressure liquid nitrogen tank to confirm whether it needs to be replenished. If replenishment is required, the input solenoid valve will feedback the pressure signal to the signal transceiver. When the BMS receives the signal from the signal transceiver, it will be fed back to the vehicle ACU, and the vehicle ACU will display the pressure value insufficient signal light through the instrument.

[0073] The signal transceiver in the fire extinguishing device is only used to transmit and send BMS signals, and also receives and sends output solenoid valve and input solenoid valve signals.

[0074] The signal transceiver in the fire extinguishing device is only used to transmit and send BMS signals, and also receives and sends output solenoid valve and input solenoid valve signals.

[0075] The input solenoid valve in the fire extinguishing device only acts to detect the high-pressure liquid nitrogen tank and transmit signals to the signal transceiver. At the same time, the switch of the solenoid valve can be controlled by the signal, thereby achieving the effect of inputting high-pressure liquid nitrogen and monitoring whether the high-pressure tank fails.

[0076] The output solenoid valve in the fire extinguishing device only acts on the signal of the receiving signal transceiver, and the switch state of the solenoid valve can be controlled by the signal controlled by the signal, thereby achieving a half-output high-pressure liquid nitrogen state and a full-output high-pressure liquid nitrogen state.

[0077] The input pipeline in the fire extinguishing device only acts when the high-pressure liquid nitrogen tank lacks high pressure, and the high-pressure liquid nitrogen is supplemented by switching the solenoid valve and connecting with special supplementary equipment.

[0078] The output pipeline in the fire extinguishing device only acts on the output state of the high-pressure liquid nitrogen tank, and the liquid nitrogen flow rate of high-pressure liquid nitrogen in different modes is carried out by switching the solenoid valve.

[0079] For the output pipeline spraying method in the fire extinguishing device, liquid nitrogen is sprayed in different ways through a pressure spraying device. When the output solenoid valve is half-opened, the pressure in the output pipeline is insufficient to open the spring pressure plate of the middle columnar injection port, and a short-distance mist spray is carried out through the surrounding annular injection ports. When the output solenoid valve is fully open, the pressure in the output pipeline is sufficient, and the pressure pushes open the spring pressure plate of the middle columnar injection port, liquid nitrogen is sprayed from the middle columnar injection port by pressure for long-distance coverage, and sprayed in a short-distance mist through the surrounding annular injection ports. Thereby, the utilization rate of limited high-pressure liquid nitrogen is improved, so that the thermal runaway state and the subsequent thermal diffusion state can be controlled by high-pressure liquid nitrogen in limited resources.

[0080] This greatly improves the safety of passengers and the prevention of fires caused by thermal runaway or thermal diffusion in the vehicle.

[0081] Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, they are all within the protection scope of the present invention.

Claims

1. A new energy power battery thermal runaway monitoring and processing system, comprising a battery management system BMS, wherein the battery management system BMS outputs a control signal to a vehicle controller for early warning control after monitoring that the battery is in a thermal runaway state; Features: The system also includes multiple independent thermal runaway monitoring modules; each thermal runaway monitoring module independently collects data corresponding to characterization or prediction of thermal runaway, and its output end is connected to the BMS. The BMS determines whether it is in a thermal runaway state based on the monitoring data collected by the multiple independent thermal runaway monitoring modules.

2. A new energy power battery thermal runaway monitoring and processing system as claimed in claim 1, characterized in that: The system also includes a smoke sensor and a fire extinguishing system, and the battery management system BMS is connected to the smoke sensor and the fire extinguishing system respectively; the BMS drives and controls the fire extinguishing system to cool the battery pack according to the signal of the smoke sensor.

3. A new energy power battery thermal runaway monitoring and processing system as claimed in claim 2, characterized in that: The fire extinguishing system includes a liquid nitrogen high-pressure tank, an outlet solenoid valve, and a nozzle arranged in a battery pack, wherein the nozzle has nozzles at multiple positions in the battery pack; the battery management system BMS controls the outlet solenoid valve of the fire extinguishing system.

4. A new energy power battery thermal runaway monitoring and processing system as described in any one of claims 1 to 3, characterized in that: A pressure relief valve is provided on the box of the power battery pack, and an air pressure sensor is provided in the battery pack. The air pressure sensor is used to detect the gas pressure value in the battery pack, and the output end of the air pressure sensor is connected to the battery management system BMS. The output end of the battery management system is connected to the pressure relief valve, which is used to control the operation of the pressure relief valve according to the internal pressure value of the battery pack after the thermal runaway warning.

5. A new energy power battery thermal runaway monitoring and processing system as described in any one of claims 1 to 3, characterized in that: A pressure sensing device is provided in the liquid nitrogen high-pressure tank, and an output end of the pressure sensing device is connected to a battery management system BMS. The battery management system BMS is used to monitor the pressure in the tank to issue a corresponding maintenance and rehydration reminder.

6. A monitoring and early warning method for a new energy power battery thermal runaway monitoring and early warning system as claimed in any one of claims 1 to 5, characterized in that: Thermal runaway monitoring data is collected through multiple channels, and thermal runaway judgment is performed based on the thermal runaway monitoring data of each channel to obtain the thermal runaway judgment result corresponding to the thermal runaway data of each channel; if there are two or more thermal runaway judgment results, it is judged that the battery is in a thermal runaway state at this time. At this time, the battery BMS feeds back the vehicle ACU to limit the vehicle power and unlock the vehicle, and sends out a corresponding early warning reminder signal.

7. The monitoring and early warning method of the new energy power battery thermal runaway monitoring and early warning system according to claim 6, characterized in that: The thermal runaway data collected by each channel is compared with the corresponding pre-designed thermal runaway conditions. When the thermal runaway data meets the corresponding thermal runaway conditions and reaches the set time threshold, the judgment result of the channel is that the battery is in a thermal runaway state; in the thermal runaway state, the thermal runaway data of each channel is collected in real time and a corresponding judgment is made. When the thermal runaway judgment result is reduced from two or more channels to one or none, the BMS feeds back a control signal to the ACU, causing it to cancel the vehicle ACU power restriction after a delay of the set time.

8. The monitoring and early warning method of the new energy power battery thermal runaway monitoring and early warning system according to claim 7, characterized in that: When it is judged to be in a thermal runaway state, the BMS monitors the smoke signal in real time through the smoke sensor. When the smoke signal is detected, it is judged that the thermal runaway state has caused a fire or there is a possibility of fire and loss of control. At this time, the BMS drives the fire extinguishing system to cool down the battery pack. If no smoke signal is detected by the smoke sensor, the BMS sends a power-off command, the entire vehicle enters the power-off state, and drives and controls the on-board alarm system to send an alarm signal to the driver and passengers, and keeps the doors unlocked.

9. The monitoring and early warning method of the new energy power battery thermal runaway monitoring and early warning system as claimed in claim 8, characterized in that: When the fire extinguishing system is started, the temperature is controlled through the outlet solenoid valve of the liquid nitrogen tank, and the opening size of the outlet solenoid valve is controlled based on the detected temperature of the battery pack.

10. The monitoring and early warning method of the new energy power battery thermal runaway monitoring and early warning system according to claim 8, characterized in that: When the fire extinguishing system starts working, the outlet solenoid valve opens to the set opening width, and then the battery pack temperature is detected. When the temperature at any position in the battery pack is greater than the set temperature threshold, the outlet solenoid valve is controlled to open fully to enable liquid nitrogen to quickly cool the battery pack.

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