A power battery-based fire prevention and extinguishing system and method

Abstract

This invention provides a fire prevention and extinguishing system and method for power batteries. A detector assembly is installed inside the battery box, and an oxygen concentration and humidity sensor, a second one-way throttling assembly, and an exhaust solenoid valve are installed on the exhaust pipe. An inert gas control unit introduces high-purity inert gas into the battery box to maintain a positive pressure environment, preventing outside air from entering and thus providing flame retardancy. When thermal runaway occurs inside the battery box, an extinguishing unit injects extinguishing agent to lower the internal temperature and prevent a chain reaction caused by excessive heat during thermal runaway. The main control unit controls the opening and closing of each solenoid valve based on signals from the sensors. Under normal conditions, the main control unit controls the inert gas control unit, while the extinguishing unit monitors the system. When excessively high internal temperature or smoke is detected in the battery box, the main control unit activates the extinguishing unit, effectively improving the reliability and feasibility of the system's fire prevention and extinguishing capabilities.

Description

Technical Field

[0001] This invention belongs to the technical field of power battery protection systems, and specifically relates to a power battery fire prevention and extinguishing system and method. Background Technology

[0002] As a core component providing power to power equipment, the safety performance of power batteries is receiving increasing attention. Improving the safety of power batteries and preventing thermal runaway has become a pressing issue for those skilled in the art.

[0003] Traditional methods involve installing dry powder fire extinguishers outside the battery compartment. When the battery catches fire due to thermal runaway, the dry powder is sprayed into the compartment to extinguish the fire. However, this method only provides passive protection after the battery has spontaneously combusted due to thermal runaway; it cannot proactively prevent spontaneous combustion or reduce the probability of thermal runaway. To address this issue, some existing methods involve filling the battery compartment with nitrogen to control the oxygen concentration within a certain range, thereby preventing spontaneous combustion due to thermal runaway. Additionally, when thermal runaway occurs, an external fire extinguishing agent is sprayed into the compartment to extinguish the flames. However, these methods still have the following three problems:

[0004] 1. Low gas replacement efficiency inside the battery box: The current method involves installing a nozzle for supplying nitrogen on the battery box casing. Nitrogen is injected into the battery box through a pipeline, and the internal gas is expelled by the battery box's own depressurization function before the battery box is refilled with nitrogen. Therefore, multiple replacements are required to control the oxygen concentration inside the battery box within a certain range, thus achieving a flame-retardant effect. However, in practical applications, the depressurization process of the battery box itself is relatively slow and takes a long time, resulting in low gas replacement efficiency inside the battery box.

[0005] 2. Exacerbating Battery Reaction After Explosion-Proof Valve Opening: When a fire occurs inside the battery compartment, current technology suppresses the fire by spraying extinguishing agents into the compartment. However, the injection of large amounts of extinguishing agents causes a rapid increase in internal pressure. When this pressure reaches a certain level, the explosion-proof valve automatically opens to release pressure. At this point, the battery compartment changes from a previously sealed inert gas environment to an open state, allowing outside air to enter. This may exacerbate the battery's combustion reaction and even cause the fire inside the battery compartment to spread to the outside, resulting in greater loss of life and property.

[0006] 3. Fire Extinguishing Device Pressure Drop Failure: When a fire occurs inside the battery box due to battery thermal failure, the current method is to extinguish the flames by spraying extinguishing agent into the battery box. However, most extinguishing agents are stored under high pressure. In practical applications, the pressure inside the fire extinguishing device pipes will decrease as the storage time increases. After long-term storage, the decrease in internal pressure may prevent the extinguishing agent from being sprayed, posing a certain safety hazard.

[0007] Therefore, how to improve the reliability and feasibility of fire prevention and extinguishing systems and methods for power batteries is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0008] The purpose of this invention is to provide a power battery fire prevention and extinguishing system and method, which can effectively improve the reliability and feasibility of the system's fire prevention and extinguishing capabilities.

[0009] To solve the above-mentioned technical problems, the present invention provides a power battery fire prevention and extinguishing system, comprising:

[0010] The battery box contains a power battery and a detector assembly. The detector assembly includes a gas pressure sensor, a temperature sensor, and a smoke sensor for monitoring the gas pressure, temperature, and smoke levels inside the battery box. The battery box is equipped with an air inlet, an exhaust outlet, and an explosion-proof valve. An exhaust pipe is provided on the exhaust outlet of the battery box. An oxygen concentration and humidity sensor, a second one-way throttling assembly, and an exhaust solenoid valve are sequentially installed on the exhaust pipe.

[0011] An inert gas control unit includes a gas storage cylinder for storing inert gas, a first one-way throttling component, and a gas storage cylinder solenoid valve. The gas storage cylinder is connected to the air inlet of the battery box in sequence through the first one-way throttling component and the gas storage cylinder solenoid valve.

[0012] A fire extinguishing unit includes a fire extinguishing device. The fire extinguishing device has a cavity, and a piston is movably disposed in the cavity. The piston divides the cavity into a gas chamber and a medium chamber for storing fire extinguishing agent. The air inlet of the fire extinguishing device is connected to the gas chamber for introducing compressed gas. The air inlet is equipped with a fire extinguishing solenoid valve. The fire extinguishing agent outlet of the fire extinguishing device is connected to the medium chamber, and the fire extinguishing agent outlet is connected to the air inlet of the battery box.

[0013] The main control unit includes a main controller, which is electrically or signal-connected to the gas pressure sensor, the temperature sensor, the smoke sensor, the oxygen concentration and humidity sensor, the exhaust solenoid valve, the gas storage cylinder solenoid valve, and the fire extinguishing solenoid valve.

[0014] Optionally, in the above-mentioned power battery fire prevention and extinguishing system, the main controller is used to control the gas storage cylinder solenoid valve and the exhaust solenoid valve to open when the gas pressure sensor detects that the gas pressure inside the battery box is less than a preset gas pressure threshold for starting to replenish inert gas, or when the oxygen concentration value detected by the oxygen concentration and humidity sensor is greater than or equal to a preset oxygen concentration inside the battery box, or when the gas humidity value is greater than or equal to a preset gas humidity inside the battery box.

[0015] When the oxygen concentration value detected by the oxygen concentration and humidity sensor is less than or equal to the preset oxygen concentration inside the battery box and the gas humidity value is less than or equal to the preset gas humidity inside the battery box, the exhaust solenoid valve is closed and the gas storage cylinder solenoid valve is opened. When the gas pressure sensor detects that the gas pressure inside the battery box is greater than the preset gas pressure threshold when the inert gas is stopped, the gas storage cylinder solenoid valve is closed.

[0016] And / or, the main controller is configured to control the fire extinguishing solenoid valve to open when the temperature sensor detects that the temperature inside the battery box is higher than a preset battery box internal temperature threshold, or the smoke sensor detects that the smoke value inside the battery box is higher than a preset smoke concentration; and to control the fire extinguishing solenoid valve to close when the temperature sensor detects that the temperature inside the battery box is not higher than the preset battery box internal temperature threshold, or the smoke sensor detects that the smoke value inside the battery box is not at a preset smoke concentration.

[0017] And / or, the main controller is used to record the time required before and after the gas pressure sensor detects the replenishment of inert gas, and when the recording time is less than the preset pressure drop time, it sends a prompt signal to the external prompting device;

[0018] And / or, the main controller is configured to control the exhaust solenoid valve to open when the gas pressure sensor detects that the gas pressure inside the battery box is higher than the preset pressure threshold for opening the exhaust solenoid valve; and to control the exhaust solenoid valve to close when the gas pressure sensor detects that the gas pressure inside the battery box is lower than the preset pressure threshold for opening the exhaust solenoid valve.

[0019] Optionally, in the above-mentioned power battery fire prevention and control system, the inert gas prevention and control unit further includes a gas generating device and a third one-way throttling component. The gas generating device is provided with an air inlet, a first air outlet, and a second air outlet. The air inlet of the gas generating device is used to introduce compressed air. The first air outlet of the gas generating device is connected to the air inlet of the gas storage cylinder. The second air outlet of the gas generating device is used to discharge the remaining gas.

[0020] Optionally, in the above-mentioned power battery fire prevention and control system, the inert gas control unit further includes an auxiliary gas cylinder and an air inlet solenoid valve. The auxiliary gas cylinder is used to store compressed air, and the auxiliary gas cylinder is connected to the air inlet of the gas generating device through the air inlet solenoid valve.

[0021] Optionally, in the above-mentioned power battery fire prevention and extinguishing system, a filter cup is provided between the air intake solenoid valve and the gas generating device for filtering the gas in the auxiliary gas cylinder of the equipment;

[0022] And / or, the inert gas control unit further includes an air compressor, a condenser, and a dryer, wherein the air compressor is connected to the auxiliary gas cylinder of the equipment in sequence through the condenser and the dryer;

[0023] And / or, the gas generating device is an air membrane separator nitrogen generator.

[0024] Optionally, in the above-mentioned power battery fire prevention and control system, the inert gas control unit further includes a gas storage cylinder pressure sensor for measuring the inert gas pressure value in the gas storage cylinder.

[0025] The gas cylinder pressure sensor is electrically or signal-connected to the main controller. The main controller is also used to determine whether to control the air intake solenoid valve to open based on the inert gas pressure value in the gas cylinder.

[0026] Optionally, in the above-mentioned power battery fire prevention and extinguishing system, the extinguishing agent in the fire extinguishing device is stored at atmospheric pressure, and the fire extinguishing solenoid valve of the fire extinguishing device is connected to the outlet of the auxiliary gas cylinder of the equipment.

[0027] And / or, a one-way valve for extinguishing fire is connected in series on the pipeline between the extinguishing agent outlet of the fire extinguishing device and the air inlet of the battery box.

[0028] Optionally, in the above-mentioned power battery fire prevention and extinguishing system, the number of battery boxes is multiple.

[0029] The present invention also provides a method for fire prevention and extinguishing of power batteries, which applies the power battery fire prevention and extinguishing system in the above specific embodiments, the method comprising:

[0030] It receives the detected gas pressure data from the gas storage cylinder, the gas pressure, temperature and smoke data inside the battery box, and the oxygen concentration and humidity data from the exhaust gas from the battery box.

[0031] In the fire suppression control logic, when the gas temperature data inside the battery box is higher than the preset battery box internal temperature threshold, or the smoke data is higher than the preset smoke concentration, the fire suppression solenoid valve is powered; when the gas pressure data inside the battery box is higher than the preset pressure threshold for opening the exhaust solenoid valve, the exhaust solenoid valve is powered; when the gas temperature data inside the battery box is lower than the preset battery box internal temperature threshold and the smoke data is lower than the preset smoke concentration, the fire suppression solenoid valve and the exhaust solenoid valve are de-energized.

[0032] In the inert gas control logic, when the gas pressure data inside the battery box is less than the preset gas pressure threshold when inert gas replenishment begins, or when the oxygen concentration data in the exhaust gas from the battery box is greater than or equal to the preset oxygen concentration inside the battery box, or when the gas humidity data is greater than or equal to the preset gas humidity inside the battery box, power is supplied to the gas storage cylinder solenoid valve and the exhaust solenoid valve. When the oxygen concentration data in the exhaust gas from the battery box is less than or equal to the preset oxygen concentration inside the battery box, and the gas humidity data is less than or equal to the preset gas humidity inside the battery box, power is de-energized to the exhaust solenoid valve. When the gas pressure data inside the battery box is greater than the preset gas pressure threshold when inert gas replenishment stops, power is de-energized to the gas storage cylinder solenoid valve. The time required before and after inert gas replenishment in the battery box is recorded. When the required time is less than the preset pressure drop time, a prompt signal is sent to the external prompting device.

[0033] In the gas production control logic, when the gas pressure data of the gas storage cylinder is less than the preset gas pressure threshold for starting gas production, the gas inlet solenoid valve is powered on; when the gas pressure data of the gas storage cylinder is greater than the preset gas pressure threshold for stopping gas production, the gas inlet solenoid valve is de-energized.

[0034] Optionally, in the above-mentioned power battery fire prevention and extinguishing method, the fire extinguishing control logic, the inert gas control logic, and the gas generation control logic are three independent logic modes that do not affect each other.

[0035] This invention provides a power battery fire prevention and extinguishing system and method, the beneficial effects of which are:

[0036] By installing gas pressure sensors, temperature sensors, and smoke sensors inside the battery box, and sequentially installing an oxygen concentration and humidity sensor, a second one-way throttling component, and an exhaust solenoid valve on the battery box's exhaust pipe, high-purity nitrogen gas is introduced into the battery box through the gas cylinder of the inert gas control unit. The gas cylinder solenoid valve controls the connection between the gas cylinder and the battery box, thereby maintaining a positive pressure environment inside the battery box, preventing outside air from entering, and thus playing a flame-retardant role, preventing combustion and explosion caused by battery thermal runaway. When thermal runaway occurs inside the battery box, a fire extinguishing unit injects a cooling and extinguishing agent into the battery box to lower the internal temperature and prevent a chain reaction caused by excessive temperature during thermal runaway. The main control unit can control the opening and closing of each solenoid valve based on the signals from each sensor. Under normal circumstances, the main control unit controls the inert gas control unit to operate, and the fire extinguishing unit monitors. When excessively high temperature or smoke is detected inside the battery box, the main control unit activates the fire extinguishing unit. By coordinating the battery box, inert gas control unit, fire extinguishing unit, and main control unit, the reliability and feasibility of the system's fire prevention and extinguishing capabilities can be effectively improved. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0038] Figure 1 This is a front view of the battery box provided in an embodiment of the present invention;

[0039] Figure 2 A rear view of the battery box provided in an embodiment of the present invention;

[0040] Figures 3-4 This is an architecture diagram of a power battery fire prevention and extinguishing system provided in an embodiment of the present invention;

[0041] Figure 5 This is a schematic diagram of the structure of the fire extinguishing device provided in an embodiment of the present invention;

[0042] Figure 6 The control logic flowchart of the power battery fire prevention and extinguishing method provided in the embodiment of the present invention is shown.

[0043] In the image above:

[0044] 100-Battery box; 110-Detector assembly; 120-Air inlet; 130-Exhaust port; 140-Explosion-proof valve; 150-Oxygen concentration and humidity sensor; 160-Second one-way throttling assembly; 170-Exhaust solenoid valve;

[0045] 210 - Auxiliary gas cylinder; 220 - Inlet solenoid valve; 230 - Filter cup; 240 - Gas generator; 250 - Third one-way throttling assembly; 260 - Gas storage cylinder; 270 - First one-way throttling assembly; 280 - Gas storage cylinder solenoid valve; 290 - Gas storage cylinder pressure sensor;

[0046] 310 - Fire extinguishing device; 311 - Air inlet; 312 - Piston; 313 - Extinguishing agent; 314 - Extinguishing agent outlet; 320 - Fire extinguishing solenoid valve; 330 - Fire extinguishing check valve;

[0047] 400 - Main Controller;

[0048] exist Figures 3-4 In the diagram, straight lines with arrows indicate the flow direction of gas or extinguishing agent when the power battery-powered fire suppression system is working; dashed lines indicate communication and power supply lines between electronic components and the main controller. It should be noted that "Inlet Solenoid Valve 220," "Fire Extinguishing Solenoid Valve 320," "Gas Storage Cylinder Solenoid Valve 280," and "Exhaust Solenoid Valve 170" are all the same device. The diagram only distinguishes the solenoid valves based on their function in the system. All solenoid valves used in the system are normally closed, meaning they are closed when no power is supplied and open when power is supplied. Similarly, "Third One-Way Throttling Assembly 250," "First One-Way Throttling Assembly 270," and "Second One-Way Throttling Assembly 160" are also the same device. The designations "First," "Second," and "Third" are merely used to distinguish one entity from another, not to indicate the order of these entities within the device. Detailed Implementation

[0049] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0050] The core of this invention is to provide a power battery fire prevention and extinguishing system and method, which can effectively improve the reliability and feasibility of the system's fire prevention and extinguishing capabilities.

[0051] To enable those skilled in the art to better understand the technical solutions provided by the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] The applications of power batteries are extremely broad, ranging from traditional automobiles, motorcycles, and industrial power systems to emerging fields such as electric aviation, low-altitude aircraft, and electric ships. With technological advancements and changing market demands, the application prospects of power batteries will become even more extensive. Therefore, the power equipment using the power batteries involved in this case can power devices with a certain degree of power, such as new energy vehicles, electric aviation, low-altitude aircraft, electric ships, and robots, by incorporating power batteries to provide electrical energy to these devices.

[0053] For details, please refer to Figures 1-6 The present invention provides a power battery fire prevention and extinguishing system and method, comprising: a battery box 100, an inert gas prevention and control unit, a fire extinguishing unit, and a main control unit;

[0054] The battery box 100 houses a power battery and a detector assembly 110. The detector assembly 110 includes a gas pressure sensor, a temperature sensor, and a smoke sensor. The gas pressure sensor detects the gas pressure inside the battery box 100, the temperature sensor detects the temperature inside the battery box 100, and the smoke sensor monitors the smoke level inside the battery box 100. The battery box 100 is equipped with an air inlet 120, an exhaust outlet 130, and an explosion-proof valve 140. The exhaust outlet 130 is connected to an exhaust pipe. The exhaust pipe is sequentially equipped with an oxygen concentration and humidity sensor 150 (which can be two sensors separately detecting oxygen concentration and exhaust gas humidity, or an integrated structure combining the two sensors), a second one-way throttling assembly 160, and an exhaust solenoid valve 170. Specifically, the exhaust solenoid valve 170 can be located at the end of the exhaust pipe. The exhaust solenoid valve 170 controls whether to exhaust the gas inside the battery box 100. Between the exhaust port 130 and the exhaust solenoid valve 170 of the battery box 100, there is also an oxygen concentration and humidity sensor 150 and a second one-way throttling component 160. The oxygen concentration and humidity sensor 150 is used to measure the oxygen concentration and humidity of the gas. Since the oxygen concentration sensor technology is relatively mature and the ratio of a certain inert gas (such as nitrogen) to oxygen in the air is fixed, this device uses the method of measuring oxygen concentration to obtain the concentration of the inert gas (such as nitrogen). The second one-way throttling component 160 is used to control the flow direction and flow rate of the gas in the exhaust pipe from the exhaust port 130 of the battery box 100 to the exhaust solenoid valve 170, to prevent air from entering the battery box 100 through the exhaust pipe when the exhaust solenoid valve 170 is open and to prevent excessive gas flow in the exhaust pipe from damaging the oxygen concentration and humidity sensor 150.

[0055] It should be noted that the gas at the air inlet 120 and exhaust outlet 130 of the battery box 100 can only flow in one direction. That is, the gas at the air inlet 120 can only enter the battery box 100 from the outside and cannot flow from the inside of the battery box 100 to the outside. Similarly, the gas at the exhaust outlet 130 can only flow from the inside of the battery box 100 to the outside and cannot enter the inside of the battery box 100 from the outside. The air inlet 120 is used to introduce the prepared high-purity inert gas into the battery box 100, and the exhaust outlet 130 is used to exhaust the gas inside the battery box 100 to the outside, thereby improving the gas replacement efficiency inside the battery box 100. The sensors included in the detector assembly 110 are used to monitor the gas pressure, temperature, and presence of smoke inside the battery box 100 to determine whether thermal runaway has occurred in the battery box 100, and then control whether to charge the battery box 100 with inert gas or release fire extinguishing agents.

[0056] It should also be noted that the air inlet 120, exhaust outlet 130, and explosion-proof valve 140 on the battery box 100 can be installed anywhere on the battery box 100, and the specific installation can be adapted according to actual needs. Figure 1 and Figure 2 As shown, the battery box 100 has an air inlet 120 and an explosion-proof valve 140 on its front side, and an exhaust port 130 on its rear side. The detector assembly 110 is located inside the battery box 100. Figure 1 The image only shows the specific location of the detector assembly 110; in reality, the built-in detector assembly 110 is not visible from the outside of the battery box 100.

[0057] The inert gas control unit is used to introduce high-purity inert gas into the battery box 100 to maintain a positive pressure environment inside the battery box 100, preventing outside air from entering the battery box 100, thereby playing a flame-retardant role and preventing combustion, explosion, and other situations caused by battery thermal runaway. The inert gas control unit specifically includes a gas storage cylinder 260 for storing inert gas, a first one-way throttling component 270, and a gas storage cylinder solenoid valve 280. The gas storage cylinder 260 is connected to the air inlet 120 of the battery box 100 in sequence through the first one-way throttling component 270 and the gas storage cylinder solenoid valve 280. The gas storage cylinder 260 is used to store the inert gas produced by the gas generating device 240, and its body has two gas ports, an inlet and an outlet. A first one-way throttling component 270 and a gas cylinder solenoid valve 280 are installed between the outlet of the gas cylinder 260 and the inlet 120 of the battery box 100. The first one-way throttling component 270 has the same function as the second one-way throttling component 160 (and the third one-way throttling component 250), namely, controlling the flow rate and direction of the gas in the pipeline. Its function is to regulate the flow rate of the high-pressure gas flowing out of the outlet of the gas cylinder 260 to prevent excessive flow of the inert gas from damaging the power battery and the detector component 110 in the battery box 100. The gas cylinder solenoid valve 280 is used to control the opening and closing of the gas pipeline between the outlet of the gas cylinder 260 and the inlet 120 of the battery box 100.

[0058] It should be noted that the inert gases stored in the gas cylinder 260 include, but are not limited to, nitrogen, argon, and helium. Nitrogen is usually used as the flame-retardant gas.

[0059] The fire extinguishing unit injects a cooling and extinguishing agent 313 into the battery box 100 when thermal runaway of the power battery occurs inside the battery box 100, reducing the internal temperature of the battery box 100 and preventing a chain reaction caused by excessive temperature during thermal runaway. Under normal circumstances, the inert gas control unit operates, and the fire extinguishing unit monitors the situation. When excessive temperature or smoke is detected inside the battery box 100, the fire extinguishing unit activates. The fire extinguishing unit specifically includes a fire extinguishing device 310, which has a cavity. A piston 312 is movable within the cavity, dividing the cavity into a gas chamber and a medium chamber for storing the extinguishing agent 313. An air inlet 311 on the fire extinguishing device 310 communicates with the gas chamber for introducing compressed gas. A fire extinguishing solenoid valve 320 is installed at the air inlet 311. The fire extinguishing agent outlet 314 on the fire extinguishing device 310 communicates with the medium chamber and is connected to the air inlet 120 of the battery box 100.

[0060] The main control unit includes a main controller 400, which is electrically or signal-connected to a gas pressure sensor, a temperature sensor, a smoke sensor, an oxygen concentration and humidity sensor 150, an exhaust solenoid valve 170, a gas storage cylinder solenoid valve 280, and a fire extinguishing solenoid valve 320.

[0061] The power battery fire prevention and extinguishing system provided in this solution includes a gas pressure sensor, a temperature sensor, and a smoke sensor installed inside the battery box 100. The battery box 100 has an air inlet 120 and an exhaust outlet 130. An oxygen concentration and humidity sensor 150, a second one-way throttling component 160, and an exhaust solenoid valve 170 are sequentially installed on the exhaust pipe connected to the exhaust outlet 130. High-purity inert gas is introduced into the battery box 100 via a gas storage cylinder 260 of the inert gas control unit. A gas storage cylinder solenoid valve 280 controls the connection between the gas storage cylinder 260 and the battery box 100, thereby maintaining a positive pressure environment inside the battery box 100, preventing outside air from entering, and thus providing flame retardancy to prevent combustion and explosion caused by battery thermal runaway. When thermal runaway of the power battery occurs inside the battery box 100, the fire extinguishing unit injects a cooling and extinguishing agent 313 into the battery box 100 to reduce the internal temperature and prevent a chain reaction caused by excessive heat during thermal runaway. The main control unit can control the opening and closing of each solenoid valve based on signals from various sensors. Under normal circumstances, the main control unit controls the inert gas control unit to operate, and the fire extinguishing unit monitors the situation. When excessively high internal temperature or smoke is detected inside the battery box 100, the main control unit controls the fire extinguishing unit to activate.

[0062] Based on the above setup, compared to existing technologies that can only guarantee the concentration of inert gas injected into the battery box meets flame retardant standards, but cannot guarantee whether the concentration of inert gas inside the battery box meets flame retardant standards, and rely solely on the natural outward permeation of gas inside the battery box until the pressure drops to the standard pressure value without a gas detection device, the advantages of this solution are:

[0063] 1. Under normal use of the power battery, by detecting the gas pressure, oxygen concentration and humidity inside the battery box 100, it can be determined whether inert gas needs to be added inside the battery box 100, so as to ensure that the concentration of inert gas inside the battery box 100 meets the flame retardant standard in real time.

[0064] 2. When it is necessary to replenish inert gas to the battery box 100, the exhaust solenoid valve 170 is opened by controlling the exhaust valve until the gas discharged from the battery box 100 meets the oxygen concentration and humidity standards. This accelerates the gas replacement process inside the battery box 100, improves the gas replacement efficiency inside the battery box, and enhances the safety of the power battery fire prevention and extinguishing system.

[0065] 3. When the pressure inside the battery box 100 exceeds the preset pressure threshold P for opening the exhaust solenoid valve nWhen the main controller 400 controls the exhaust solenoid valve 170 to open, it avoids the problem that the internal pressure of the battery box 100 will increase sharply when the fire extinguishing agent is sprayed into the battery box 100, causing the explosion-proof valve 140 to open automatically, which would destroy the inert gas environment inside the battery box 100 and aggravate the thermal runaway of the battery, or even cause the fire inside the battery box to spread to the outside of the battery box, thus increasing safety.

[0066] 4. Since a positive pressure needs to be maintained inside the battery box 100 after inert gas is introduced, the airtightness of the battery box 100 gradually deteriorates over time. This invention monitors the airtightness of the battery box 100 by recording the time it takes for the internal pressure to drop after inert gas is introduced. As time progresses, when the airtightness deteriorates, this situation can be promptly reported to relevant personnel, enabling them to perform maintenance. This avoids the safety hazard of water or other liquids entering the battery box due to deteriorated airtightness.

[0067] By cooperating with the battery box 100, the inert gas control unit, the fire extinguishing unit, and the main control unit, the reliability and feasibility of the system's fire prevention and extinguishing capabilities can be effectively improved.

[0068] In a further specific implementation, the control method of the main control unit includes:

[0069] Method 1: The main controller 400 is used to detect when the gas pressure sensor detects that the gas pressure P2 inside the battery box is less than the preset threshold P for starting inert gas replenishment. c The oxygen concentration C detected by the oxygen concentration and humidity sensor 150 at the battery compartment exhaust port is greater than or equal to the preset oxygen concentration C inside the battery compartment. m Or the humidity H of the gas at the battery box exhaust port is greater than or equal to the preset humidity H of the gas inside the battery box. m When inert gas needs to be injected into the battery box 100, the gas storage cylinder solenoid valve 280 and the exhaust solenoid valve 170 are opened; when the oxygen concentration C at the battery box exhaust port detected by the oxygen concentration and humidity sensor 150 is less than or equal to the preset oxygen concentration C inside the battery box... m Furthermore, the humidity H of the gas at the battery box exhaust port is less than or equal to the preset humidity H of the gas inside the battery box. m When the gas pressure sensor detects that the internal gas pressure P2 of the battery compartment is greater than the preset threshold P for stopping inert gas replenishment, the internal gas pressure P of the battery compartment will be closed. d If necessary, the injection of inert gas into the battery box 100 should be stopped, and the solenoid valve 280 of the gas storage bottle should be closed.

[0070] This can be understood as the gas pressure threshold P inside the battery box 100 decreasing to the preset threshold P when inert gas replenishment begins due to gas infiltration. c The oxygen concentration C detected by the oxygen concentration and humidity sensor 150 at the battery compartment exhaust port is greater than or equal to the preset oxygen concentration C inside the battery compartment. m Or the humidity H of the gas at the battery box exhaust port is greater than the preset humidity H of the gas inside the battery box. m At this time, the main controller 400 controls the gas cylinder solenoid valve 280 and the exhaust solenoid valve 170 to open, and the inert gas in the gas cylinder 260 flows out from the outlet of the gas cylinder 260, passes through the first one-way throttling component 270 and the gas cylinder solenoid valve 280, and is injected into the battery box 100 through the air inlet 120. This stage can be regarded as the first stage. When the gas at the exhaust port 130 is not up to standard, inert gas is injected into the battery box 100. At this time, the exhaust solenoid valve 170 is in the open state, so the gas pressure value inside the battery box 100 will not increase much. The purpose at this time is to expel as much of the original gas inside the battery box as possible by injecting inert gas into the battery box 100.

[0071] After the main controller 400 opens the gas cylinder solenoid valve 280 and the exhaust solenoid valve 170, the oxygen concentration of the gas discharged from the exhaust port 130 decreases due to the injection of inert gas. When the oxygen concentration C detected by the oxygen concentration and humidity sensor 150 at the exhaust port 130 on the battery box 100 is less than or equal to the preset oxygen concentration C inside the battery box... m Furthermore, the humidity H of the gas at the exhaust port 130 on the battery box 100 is less than or equal to the preset humidity H of the gas inside the battery box. m At this time, the main controller 400 controls the exhaust solenoid valve 170 to close. Continuing to inject inert gas into the battery box 100 at this time will increase the gas pressure inside the battery box 100. When the gas pressure inside the battery box 100 increases to a preset threshold P at which inert gas replenishment is stopped, the gas pressure inside the battery box will continue to rise. d At this time, the main controller 400 controls the gas cylinder solenoid valve 280 to close, stopping the filling of inert gas into the battery box 100. This stage can be regarded as the second stage. When the gas at the exhaust port 130 reaches the standard, the exhaust solenoid valve 170 is controlled to close. This means that inert gas is injected into the battery box 100 to make the gas pressure inside the battery box 100 reach the preset value, and then the gas cylinder solenoid valve 280 is closed.

[0072] When the gas cylinder solenoid valve 280 is opened, it controls the exhaust solenoid valve 170 to open, simultaneously replenishing the battery box 100 with inert gas and simultaneously venting the gas, thus accelerating the gas replacement process inside the battery box 100 and improving the gas replacement efficiency inside the battery box 100.

[0073] Method 2: The main controller 400 is used when the temperature sensor detects that the temperature T inside the battery box 100 is higher than the preset internal temperature threshold T of the battery box. m If the smoke sensor detects that the smoke concentration inside the battery compartment 100 reaches the preset smoke concentration, it indicates that the internal temperature of the battery compartment 100 is too high or that smoke is present, and the fire extinguishing solenoid valve 320 is opened. If the temperature sensor detects that the internal temperature T of the battery compartment 100 is not higher than the preset internal temperature threshold T, the fire extinguishing solenoid valve 320 is opened. m If the smoke sensor detects that the smoke level inside the battery box 100 has not reached the preset smoke concentration, it indicates that the battery box 100 is in normal working condition and controls the fire extinguishing solenoid valve 320 to close.

[0074] When the internal temperature T of the battery box 100 is detected to be too high or smoke is present, the main controller 400 controls the fire extinguishing solenoid valve 320 to open, and the fire extinguishing unit starts working. Specifically, compressed gas is introduced into the gas chamber through the air inlet on the fire extinguishing device 310. The compressed gas pushes the piston 312 towards the medium chamber, allowing the extinguishing agent 313 to enter the air inlet 120 of the battery box 100 from the extinguishing agent outlet 314 for fire extinguishing. Under normal circumstances, the inert gas control unit operates, the main controller 400 controls the fire extinguishing solenoid valve 320 to close, and the fire extinguishing unit monitors the situation.

[0075] Since thermal runaway of a battery is often accompanied by an increase in temperature and the generation of smoke, temperature sensors and smoke sensors are used to detect whether thermal runaway has occurred in the battery inside the battery box 100. The main controller 400 then controls whether to inject fire extinguishing agent 313 into the battery box 100, that is, whether to open the fire extinguishing solenoid valve 320.

[0076] Method 3: The main controller 400 is used to record the time required for the preset gas pressure difference detected by the gas pressure sensor (i.e., the time required for the gas pressure inside the battery box to change from P...). d Reduced to P c The time used (t), when the recording time is less than the preset pressure drop time (the preset internal gas pressure of the battery box is P) d Reduced to P c When the time taken is N), a prompt signal is sent to the external prompting device.

[0077] After adding inert gas to the battery box 100, the airtightness of the battery box 100 is monitored by recording the time it takes for the internal air pressure to drop. If the air pressure drop time is too short, it indicates that the airtightness of the battery box 100 has deteriorated, prompting maintenance personnel to carry out maintenance.

[0078] Method 4: The main controller 400 is used when the gas pressure sensor detects that the gas pressure inside the battery box 100 reaches the preset pressure threshold P for opening the exhaust solenoid valve. nWhen the gas pressure sensor detects that the gas pressure inside the battery compartment 100 is less than the preset pressure threshold P for opening the exhaust solenoid valve, the exhaust solenoid valve will open. n At that time, the exhaust solenoid valve 170 is closed.

[0079] It should be noted that when the gas pressure inside the battery box 100 exceeds the pressure threshold P that automatically opens the explosion-proof valve... m In this case, the explosion-proof valve 140 can open automatically. To prevent the explosion-proof valve 140 from automatically opening when the extinguishing agent is sprayed into the battery box 100, a preset pressure threshold P for opening the exhaust solenoid valve is specifically set. n And P n The value is greater than the preset gas pressure threshold P inside the battery box when inert gas replenishment stops. d The pressure threshold P for the explosion-proof valve to automatically open is less than the threshold pressure. m When the gas pressure inside battery compartment 100 is detected to be higher than P... n At this time, the main controller 400 controls the exhaust solenoid valve 170 to open, thereby preventing the gas pressure inside the battery box 100 from exceeding the pressure threshold P for the explosion-proof valve to open automatically. m This causes the explosion-proof valve to open automatically. That is, P n The value is within the preset threshold P of the internal gas pressure of the battery compartment when inert gas replenishment stops. d The threshold P for automatic opening of the explosion-proof valve m Between (P) d <P n <P m ).

[0080] By setting an opening threshold for the exhaust solenoid valve 170, the explosion-proof valve 140 is prevented from automatically opening when the extinguishing agent is sprayed into the battery box 100, and external gas entering the battery box 100 is prevented from aggravating the battery combustion reaction.

[0081] In a specific embodiment, such as Figure 4 As shown, the inert gas control unit also includes a gas generator 240 and a third one-way throttling component 250 for producing inert gas. The gas generator 240 has a one-inlet, two-outlet structure, which generates and purifies the required inert gas through a series of physical and chemical processes. The gas generator 240 is equipped with an air inlet, a first outlet, and a second outlet. The air inlet of the gas generator 240 is used to introduce compressed air. The first outlet of the gas generator 240 is connected to the air inlet of the gas storage cylinder 260, facilitating the storage of the produced inert gas in the form of high-pressure gas in the gas storage cylinder 260. The second outlet of the gas generator 240 is used to discharge the remaining gas.

[0082] Specifically, the inlet of the gas cylinder 260 is connected to the gas generating device 240, and the outlet of the gas cylinder 260 is connected to the battery box 100. The second outlet of the gas generating device 240 is connected to the outside, discharging other gases after filtering the inert gas into the air. The function of the third one-way throttling component 250 between the gas generating device 240 and the gas cylinder 260 is to control the flow rate of the inert gas in the pipeline and to control the one-way flow of the inert gas in the pipeline, that is, the inert gas can only flow from the first outlet of the gas generating device 240 to the inlet of the gas cylinder 260, and cannot flow from the inlet of the gas cylinder 260 to the first outlet of the gas generating device 240.

[0083] It is understandable that the "first one-way throttling component 270", "second one-way throttling component 160" and "third one-way throttling component 250" can adopt the same structure or different structures. The above-mentioned one-way throttling components can be one-way throttling valves, which play the role of controlling the flow direction and flow rate. They can also be replaced by a combination of one-way valves and pressure stabilizing structures, which will not be elaborated here.

[0084] In a further specific embodiment, the inert gas control unit also includes an auxiliary gas cylinder 210 and an inlet solenoid valve 220. The auxiliary gas cylinder 210 is used to store compressed air, and the auxiliary gas cylinder 210 is connected to the air inlet of the gas generating device 240 through the inlet solenoid valve 220.

[0085] Among them, the equipment auxiliary gas cylinder 210 is a gas storage cylinder that is built into the power equipment itself. The air inlet of the gas generating device 240 is connected to the equipment auxiliary gas cylinder 210, and the equipment auxiliary gas cylinder 210 is used as a gas source. The air inlet solenoid valve 220 is used to control whether compressed air enters the gas generating device 240 to generate inert gas. The purpose of setting the third one-way throttling component 250 is also to prevent the high-pressure inert gas in the gas storage cylinder 260 from flowing from the air inlet of the gas storage cylinder 260 to the first air outlet of the gas generating device 240 when the air inlet solenoid valve 220 is closed.

[0086] In a specific embodiment, a filter cup 230 is provided between the air intake solenoid valve 220 and the gas generating device 240 to filter the gas in the auxiliary gas cylinder 210 of the equipment, so as to prevent small particulate impurities in the gas from clogging and damaging the inert gas separation membrane in the gas generating device.

[0087] The inert gas control unit also includes an air compressor, a condenser, and a dryer. The air compressor is connected to the auxiliary gas cylinder 210 via the condenser and dryer. When the power equipment starts, its built-in air compressor begins operation, compressing air and storing it in the auxiliary gas cylinder for use during operation. A filter can also be installed in front of the air compressor to filter dust particles from the air. A condenser and dryer are installed between the air compressor and the auxiliary gas cylinder 210 for dehumidifying the compressed air. This part of the device is not described in detail. Figure 3 and Figure 4 As shown in the architecture diagram, the gas stored in the auxiliary gas cylinder 210 is filtered and dried compressed air.

[0088] Of course, the auxiliary gas cylinder 210 used as a gas source can be replaced by an air compressor or air pump. That is, compressed air can be directly supplied by an air compressor or air pump, without the need to set up an auxiliary gas cylinder 210 as a storage device.

[0089] like Figure 4 As shown, the auxiliary gas cylinder 210, inlet solenoid valve 220, gas generating device 240, third one-way throttling component 250, gas storage cylinder 260, first one-way throttling component 270, gas storage cylinder solenoid valve 280, battery box 100, oxygen concentration and humidity sensor 150, second one-way throttling component 160 and exhaust solenoid valve 170 are arranged sequentially along the gas flow direction.

[0090] In particular, when nitrogen is used as the inert gas, the gas generating device 240 is an air membrane separation nitrogen generator, which obtains high-purity nitrogen through filtration.

[0091] The inert gas control unit also includes a gas cylinder pressure sensor 290 installed in the gas cylinder 260, which measures the inert gas pressure P1 in the gas cylinder 260 and feeds it back to the main controller 400.

[0092] The gas cylinder pressure sensor 290 is electrically or signal-connected to the main controller 400. The main controller 400 is also used to determine whether to control the air intake solenoid valve 220 to open based on the inert gas pressure P1 in the gas cylinder 260, so that the compressed air in the auxiliary gas cylinder 210 enters the gas generating device 240 to prepare the inert gas.

[0093] In a further embodiment, in order to avoid the safety hazards of pressure drop and failure of extinguishing agent to be sprayed due to high-pressure storage of extinguishing agent, the extinguishing agent 313 in the fire extinguishing device 310 is stored at normal pressure, and the fire extinguishing solenoid valve 320 of the fire extinguishing device 310 is connected to the outlet of the auxiliary gas cylinder 210 of the equipment.

[0094] Among them, extinguishing agent 313 can use perfluorohexane, which is liquid at room temperature and easily vaporizes. After vaporization, it can absorb a large amount of heat, is not easily combustible, and can be used to extinguish battery fires without polluting the battery surface. In addition, perfluorohexane has an ozone depletion potential (ODP) of 0, a global greenhouse potential (GWP) of 1, and an atmospheric survival life (years) of 0.014 (5 days). Its extinguishing concentration is 4-6%, with a relatively high safety margin. Of course, perfluorohexane is only one type of extinguishing agent, and other types of extinguishing agents can be used as substitutes. Using these types of extinguishing agents can quickly absorb the large amount of heat generated during thermal runaway of the power battery, thereby suppressing the thermal runaway of the power battery.

[0095] The fire extinguishing device 310 uses the auxiliary gas cylinder 210 as its gas source and pushes the extinguishing agent 313 out by the piston 312. The structure of the fire extinguishing device 310 is as follows: Figure 5 As shown. The air inlet 311 of the fire extinguishing device 310 is connected to the equipment auxiliary gas cylinder 210, and the fire extinguishing agent outlet 314 is connected to the pipeline between the gas cylinder solenoid valve 280 and the air inlet 120 of the battery box 100. A fire extinguishing solenoid valve 320 is also included between the equipment auxiliary gas cylinder 210 and the air inlet 311 of the fire extinguishing device 310. This fire extinguishing solenoid valve 320 is used to control whether the gas in the equipment auxiliary gas cylinder 210 is introduced into the fire extinguishing device 310, thereby pushing the piston 312 to spray the fire extinguishing agent 313 into the battery box 100.

[0096] The extinguishing agent outlet 314 of the fire extinguishing device 310 is also equipped with a one-way extinguishing valve 330 on the pipeline between it and the air inlet 120 of the battery box 100. The one-way extinguishing valve 330 is used to control the one-way flow of gas and extinguishing agent 313. That is, the extinguishing agent 313 can only flow from the extinguishing agent outlet 314 of the fire extinguishing device 310 to the air inlet 120 of the battery box 100. This prevents the high-pressure inert gas in the gas storage cylinder from entering the fire extinguishing device 310 through the pipeline when the gas storage cylinder solenoid valve 280 is opened.

[0097] When there are multiple battery boxes 100, the power battery fire prevention and extinguishing system can simultaneously control multiple battery boxes 100.

[0098] When inert gas needs to be added to the battery box 100, the gas cylinder solenoid valve 280 and the exhaust solenoid valve 170 are opened. The high-pressure inert gas in the gas cylinder 260 flows out from the outlet of the gas cylinder 260 and is injected into the battery box 100 through the first one-way throttling component 270, the gas cylinder solenoid valve 280 and the air inlet 120 of the battery box 100. Meanwhile, the gas in the battery box 100 is discharged into the air through the exhaust port 130 of the battery box 100, the oxygen concentration and humidity sensor 150, the second one-way throttling component 160 and the exhaust solenoid valve 170. If the oxygen concentration and humidity sensor 150 detects that the gas concentration and humidity discharged from the battery box 100 both meet the standard, the main controller 400 controls the exhaust solenoid valve 170 to close and continues to inject inert gas into the battery box 100 until the gas pressure inside the battery box 100 reaches the preset value. Then, the gas storage cylinder solenoid valve 280 is closed to complete the replenishment of inert gas into the battery box 100. If the oxygen concentration and humidity sensor 150 detects that the gas concentration or humidity discharged from the battery box 100 does not meet the standard, and the gas generating device 240 produces inert gas once, and the oxygen concentration and humidity sensor 150 still detects that the gas concentration or humidity discharged from the battery box 100 does not meet the standard, then the fault is reported. After the inert gas supply to the battery box 100 is completed, both the gas cylinder solenoid valve 280 and the exhaust solenoid valve 170 are closed. At this time, the oxygen concentration and humidity sensor 150 can measure the oxygen concentration and humidity of the gas inside the battery box 100. When the oxygen concentration or humidity of the gas inside the battery box 100 does not meet the standard, or when the gas pressure inside the battery box 100 drops below the inert gas supply standard, the main controller 400 controls the gas cylinder solenoid valve 280 and the exhaust solenoid valve 170 to open, supplying inert gas to the battery box 100. The above process can ensure that the inert gas concentration inside the battery box meets the flame retardant standard in real time, preventing combustion, explosion, and other situations caused by thermal runaway of the power battery.

[0099] In addition, since the battery box 100 is filled with inert gas and is in a positive pressure environment, there is a pressure difference between the inside and outside of the battery box. Therefore, the airtightness of the battery box 100 will gradually decrease over time. In order to prevent outside air or water from entering the battery box and causing safety hazards due to poor airtightness, this system is equipped with a battery box airtightness fault alarm. When the airtightness of the battery box is poor, an alarm will be triggered, and maintenance personnel will be notified to carry out maintenance. The method is as follows: After replenishing the battery box with inert gas, the gas inside the battery box will permeate until the internal pressure drops to the standard level for replenishing inert gas. Then, the battery box is refilled with inert gas (referred to as refilling). During the process between the completion of the previous refill and the start of the next refill, the internal pressure of the battery box is a pressure drop process. Since the pressure difference between the internal pressure of the battery pack at the start of refilling and the internal pressure at the end of refilling is a constant value, the main controller 400 records the pressure drop time after each refill and compares it with a preset time value. When the pressure drop time after a certain refill is less than the preset time value, it indicates that the internal pressure of the battery box drops too quickly, that is, the airtightness of the battery box has deteriorated significantly. At this time, the main controller 400 issues an airtightness deterioration alarm and notifies maintenance personnel to carry out maintenance. Before maintenance is carried out, the battery box refilling operation continues.

[0100] When the temperature sensor and smoke sensor inside the battery box 100 detect that the internal temperature of the battery box is too high or that smoke is present inside the battery box, the main controller 400 controls the fire extinguishing solenoid valve 320 to open. High-pressure gas from the auxiliary gas cylinder 210 enters the fire extinguishing device 310, pushing the piston 312 to move. This, in turn, pushes the cooling extinguishing agent 313 through the pipeline into the battery box 100 via the air inlet 120, suppressing battery thermal runaway. Simultaneously, the pressure sensor inside the battery box 100 monitors the internal pressure in real time. If the internal pressure of the battery box 100 reaches a preset value P... n (and P) n The internal gas pressure P of the battery compartment exceeds the threshold value when inert gas replenishment is stopped. d The pressure is below the pressure threshold P that automatically opens the explosion-proof valve. mIf the pressure inside the battery box 100 is too high, the main controller 400 will open the exhaust solenoid valve 170 to release pressure, preventing outside air from entering the battery box and disrupting the inert gas environment inside, thus exacerbating the battery reaction and potentially causing the fire to spread to the outside. When the cooling extinguishing agent 313 is sprayed into the battery box 100, the temperature and smoke sensors inside the battery box monitor the temperature and smoke levels. Once the temperature drops and the smoke dissipates, the main controller 400 will close the extinguishing solenoid valve 320 and the exhaust solenoid valve 170. Subsequently, the temperature and smoke sensors inside the battery box continue to monitor the interior to prevent secondary reignition of the battery.

[0101] Furthermore, this solution also provides a method for preventing and extinguishing fires involving power batteries, characterized by applying the power battery fire prevention and extinguishing system described in the above specific embodiments, the method comprising:

[0102] S100 receives gas pressure data from the gas storage cylinder 260, gas pressure, temperature and smoke data inside the battery box 100, and oxygen concentration and humidity data in the exhaust gas from the battery box 100, respectively; the above data are respectively from the gas storage cylinder pressure sensor 290, gas pressure sensor, temperature sensor, smoke sensor and oxygen concentration and humidity sensor 150.

[0103] S200. In the fire suppression control logic, when the internal gas temperature data of the battery box 100 is higher than the preset internal temperature threshold T of the battery box... m When the smoke concentration data exceeds the preset smoke concentration, power is supplied to the fire extinguishing solenoid valve 320, pushing the fire extinguishing agent 313 into the battery box 100. When the gas pressure data inside the battery box 100 exceeds the preset exhaust solenoid valve opening pressure threshold P, n When the solenoid valve 170 is powered, the battery box 100 is vented. When the internal gas temperature of the battery box 100 is lower than the preset internal temperature threshold T, the venting process continues. m Furthermore, when the smoke data is lower than the preset smoke concentration, the power to the fire extinguishing solenoid valve 320 and the exhaust solenoid valve 170 is cut off.

[0104] S300. In the inert gas control logic, when the gas pressure inside the battery box 100 is less than the preset gas pressure threshold P at the start of inert gas replenishment... c Or, the oxygen concentration data in the exhaust of battery box 100 is greater than or equal to the preset oxygen concentration C inside the battery box. m Or the gas humidity data is greater than or equal to the preset internal gas humidity H of the battery box. mWhen the gas cylinder solenoid valve 280 and the exhaust solenoid valve 170 are powered, the gas inside the battery box 100 is replaced. When the oxygen concentration in the exhaust of the battery box 100 is less than or equal to the preset oxygen concentration C inside the battery box... m Furthermore, the gas humidity data is less than or equal to the preset internal gas humidity H of the battery box. m When the power is off to the exhaust solenoid valve 170, and the internal gas pressure of the battery box 100 exceeds the preset threshold P for stopping the replenishment of inert gas, the internal gas pressure of the battery box will be stopped. d At that time, the solenoid valve 280 of the gas storage cylinder is de-energized, and the time required before and after the battery box 100 is replenished with inert gas is recorded (i.e., the gas pressure inside the battery box changes from P to P). d Reduced to P c (Time taken), when the required time is less than the preset pressure drop time (the preset internal gas pressure of the battery box is P) d Reduced to P c When the time taken is not less than the preset voltage drop time, a prompt signal is sent to the external prompting device. If the required time is not less than the preset voltage drop time, no feedback is required.

[0105] S400. In the gas production control logic, when the gas pressure data of the gas storage cylinder 260 is less than the preset gas pressure threshold P of the gas storage cylinder when gas production starts. a When the gas pressure data of the gas storage cylinder 260 exceeds the preset gas pressure threshold P for stopping gas production, the gas supply solenoid valve 220 is powered. b At that time, the power to the intake solenoid valve 220 is cut off.

[0106] Among them, the fire extinguishing control logic S200, the inert gas control logic S300, and the gas generation control logic S400 are three independent logic modes that do not affect each other.

[0107] Furthermore, in the gas production control logic, to avoid potential safety hazards, if the duration of a single nitrogen production exceeds the preset time M required for one inert gas production, that is, if the opening time of the intake solenoid valve 220 exceeds the preset time M required for one inert gas production, the main controller 400 will forcibly close the intake solenoid valve 220, stop the gas production device 240 from working, and report a fault code to the instrument display of the power equipment.

[0108] Obviously, the power battery fire prevention and extinguishing method using the above-mentioned power battery fire prevention and extinguishing system has the same beneficial effect, and will not be elaborated here.

[0109] To further illustrate the present invention, the following describes in detail, with reference to embodiments, a power battery fire prevention and extinguishing system and method.

[0110] In the specific embodiments below, the power equipment is a new energy vehicle, the inert gas used in the battery box is nitrogen, and there are two battery boxes. The symbols and their corresponding explanations are shown in Table 1. The control logic flowchart corresponding to this embodiment is as follows: Figure 6 As shown. Figure 6 It includes fire extinguishing control logic S200, inert gas control logic S300, and gas generation control logic S400. It should be noted that these three logics do not affect each other; therefore, in... Figure 6 The three logic sequences mentioned above are implemented in parallel; furthermore, all solenoid valves used in this system are normally closed solenoid valves, which are closed when power is off and open when power is supplied. Figure 6 In the control logic flow shown, "powering the solenoid valve" means opening the solenoid valve.

[0111] In the gas control logic S400, when the gas cylinder pressure sensor 290 detects that the gas cylinder pressure P1 is lower than the preset value P... a When the main controller 400 controls the intake solenoid valve 220 to open, compressed air from the auxiliary gas cylinder 210 enters the inlet of the gas generator 240 through a pipeline to generate nitrogen. The nitrogen outlet of the gas generator 240 is connected to the storage cylinder 260, so the generated nitrogen is stored in the storage cylinder 260 in the form of high-pressure gas. When the gas pressure P1 in the storage cylinder 260 reaches the preset value P... b When this occurs, the main controller 400 closes the intake solenoid valve 220, preventing compressed air from entering the intake port of the gas generator 240, thus stopping nitrogen production. Furthermore, to avoid safety hazards, if a single nitrogen production cycle exceeds one hour (M can be 60 minutes), meaning the intake solenoid valve 220 is open for more than one hour at a time, the main controller 400 will forcibly close the intake solenoid valve 220, stopping nitrogen production by the gas generator 240 and sending a fault code to the vehicle's instrument panel display.

[0112] In the inert gas control logic S300, when the pressure sensors in the two battery compartments detect the internal gas pressure P of the two battery compartments... 2,1 and P 2,2 There is a pressure value that is lower than the preset nitrogen filling pressure P. c Alternatively, oxygen concentration and humidity sensors connected to the two battery compartments may detect that the oxygen concentration C inside the two battery compartments is higher than the preset oxygen standard C. m Or the gas humidity H is higher than the preset gas humidity H m At this time, the main controller 400 controls the gas cylinder solenoid valve 280 and the exhaust solenoid valve 170 to open, replacing the gas inside the two battery compartments. This continues until the oxygen concentration C in the gas discharged from the battery compartments is lower than the preset oxygen standard C. m And the gas humidity H is lower than the preset gas humidity H mAt this time, the main controller 400 controls the exhaust solenoid valve 170 to close, while the gas storage cylinder solenoid valve 280 remains open, filling the two battery boxes with nitrogen until the gas pressure P inside the two battery boxes reaches a certain level. 2,1 and P 2,2 Reaching the preset nitrogen purging stop standard P d At this time, the main controller 400 controls the solenoid valve 280 of the gas storage cylinder to close. The main controller 400 records the times t1 and t2 during the pressure drop process from the end of this nitrogen filling to the start of the next nitrogen filling, and, combined with the triggering factors at the start of the next nitrogen filling, determines whether this pressure drop process is a complete pressure drop process. A complete pressure drop process refers to the pressure inside the battery box decreasing from P... d Reduced to P c This process. When the gas concentration or humidity inside the battery box does not meet the standard and nitrogen filling is performed, the gas pressure inside the battery box has not been reduced to P before nitrogen filling. c Therefore, the pressure drop process inside the battery box at this time cannot be considered a complete pressure drop process. If it is, then t1 and t2 are compared with the preset pressure drop time to determine if there is a problem with the airtightness of the battery box; if there is no problem, then the battery box is charged with nitrogen again.

[0113] In the fire suppression control logic S200, when the internal temperature T1 or T2 of the two battery boxes is higher than the preset internal temperature T of the battery boxes... m If the smoke sensor detects smoke inside the battery compartment, the main controller 400 will issue a fire alarm and simultaneously control the fire extinguishing solenoid valve 320 to open, using high-pressure air from the auxiliary gas cylinder 210 to spray the cooling extinguishing agent 313 into the battery compartment 100. At the same time, pressure sensors inside both battery compartments will monitor the internal air pressure P in real time. 2,1 and P 2,2 If P 2,1 or P 2,2 The pressure P required to open the exhaust solenoid valve is higher than the preset threshold. n If the main controller 400 controls the corresponding battery box's exhaust solenoid valve 170 to open, it will depressurize the battery box to prevent the explosion-proof valve 140 above the battery box 100 from opening. If the temperature and smoke sensors inside the battery box detect that the internal temperature of the battery box has dropped and the smoke has dissipated, the main controller 400 will control the fire extinguishing solenoid valve 320 and the exhaust solenoid valve 170 to close. At the same time, the temperature and smoke sensors inside the battery box will continue to monitor the inside of the battery box to prevent secondary reignition.

[0114] surface Symbols and their corresponding explanations

[0115] symbol illustrate <![CDATA[P1]]> Gas pressure in the gas cylinder (unit: kPa) <![CDATA[P 2,1 ]]> Gas pressure inside the first battery compartment (unit: kPa) <![CDATA[P 2,2 ]]> Gas pressure inside the second battery compartment (unit: kPa) <![CDATA[P a ]]> The preset gas pressure threshold of the gas storage cylinder at the start of gas production (unit: kPa). <![CDATA[P b ]]> Preset gas pressure threshold for the gas storage cylinder when gas production stops (unit: kPa) <![CDATA[P c ]]> Preset gas pressure threshold inside the battery compartment when inert gas is first added (unit: kPa) <![CDATA[P d ]]> Preset gas pressure threshold inside the battery compartment when inert gas replenishment stops (unit: kPa) <![CDATA[P m ]]> Pressure threshold for automatic opening of explosion-proof valve (unit: kPa) <![CDATA[P n ]]> <![CDATA[The preset exhaust solenoid valve opening pressure threshold (unit: kpa) and P d <P n <P m > <![CDATA[T1]]> Temperature inside the first battery compartment (unit: °C) <![CDATA[T2]]> Temperature inside the second battery compartment (unit: °C) <![CDATA[T m ]]> Preset internal temperature threshold for the battery compartment (unit: °C) C Oxygen concentration at the battery compartment exhaust port <![CDATA[C m ]]> Preset oxygen concentration inside the battery compartment H humidity of the gas at the battery compartment exhaust port <![CDATA[H m ]]> Preset humidity level inside the battery compartment <![CDATA[t1]]> <![CDATA[The time (unit: min) taken for the internal gas pressure of the first battery box to drop from P d to P c after the addition of inert gas]]> <![CDATA[t2]]> <![CDATA[After supplementing the inert gas, the internal gas pressure of the second battery box drops from P d to P c The time taken (unit: min)]]> M Preset the time required to prepare an inert gas in one step (unit: min). N <![CDATA[The time (unit: min) taken for the preset internal gas pressure of the battery box to drop from P d to P c >

[0116] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0117] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A power battery-based fire prevention and extinguishing system, characterized in that, include: The battery box (100) contains a power battery and a detector assembly (110). The detector assembly (110) includes a gas pressure sensor, a temperature sensor, and a smoke sensor for monitoring the gas pressure, temperature, and smoke levels inside the battery box (100). The battery box (100) is provided with an air inlet (120), an exhaust outlet (130), and an explosion-proof valve (140). An exhaust pipe is provided on the exhaust outlet (130) of the battery box (100). An oxygen concentration and humidity sensor (150), a second one-way throttling assembly (160), and an exhaust solenoid valve (170) are sequentially provided on the exhaust pipe. The inert gas control unit includes an auxiliary gas cylinder (210), an inlet solenoid valve (220), a gas generator (240), a third one-way throttling assembly (250), a gas storage cylinder (260) for storing inert gas, a first one-way throttling assembly (270), and a gas storage cylinder solenoid valve (280). The auxiliary gas cylinder (210) is used to store compressed air. The gas generator (240) is provided with an air inlet, a first outlet, and a second outlet. The air inlet of the gas generator (240) is used to introduce compressed air. The auxiliary gas cylinder (210) of the equipment is connected to the air inlet of the gas generating device (240) through the air inlet solenoid valve (220). The first outlet of the gas generating device (240) is connected to the air inlet of the gas storage cylinder (260). The second outlet of the gas generating device (240) is used to discharge the remaining gas. The gas storage cylinder (260) is connected to the air inlet (120) of the battery box (100) in sequence through the first one-way throttling component (270) and the gas storage cylinder solenoid valve (280). The fire extinguishing unit includes a fire extinguishing device (310), which has a cavity. A piston (312) is movably disposed in the cavity. The piston (312) divides the cavity into a gas chamber and a medium chamber for storing fire extinguishing agent (313). The air inlet (311) on the fire extinguishing device (310) is connected to the gas chamber for introducing compressed gas. The air inlet (311) on the fire extinguishing device (310) is equipped with a fire extinguishing solenoid valve (320). The fire extinguishing agent outlet (314) on the fire extinguishing device (310) is connected to the medium chamber. The fire extinguishing agent outlet (314) is connected to the air inlet (120) of the battery box (100). The main control unit includes a main controller (400), which is electrically or signal-connected to the gas pressure sensor, the temperature sensor, the smoke sensor, the oxygen concentration and humidity sensor (150), the exhaust solenoid valve (170), the gas storage cylinder solenoid valve (280), and the fire extinguishing solenoid valve (320).

2. The power battery fire prevention and extinguishing system according to claim 1, characterized in that, The main controller (400) is configured to, when the gas pressure sensor detects that the gas pressure inside the battery box (100) is less than a preset inert gas replenishment threshold P, trigger the gas pressure sensor to activate the inert gas replenishment. c Or, the oxygen concentration value detected by the oxygen concentration and humidity sensor (150) is greater than or equal to the preset oxygen concentration C inside the battery box. m Or the gas humidity value is greater than or equal to the preset internal gas humidity H of the battery box. m At that time, the solenoid valve (280) of the gas storage cylinder and the solenoid valve (170) are opened; When the oxygen concentration value detected by the oxygen concentration and humidity sensor (150) is less than or equal to the preset oxygen concentration C inside the battery box m And the gas humidity value is less than or equal to the preset internal gas humidity H of the battery box. m When the exhaust solenoid valve (170) is closed and the gas cylinder solenoid valve (280) is opened, the gas pressure sensor detects that the gas pressure inside the battery box (100) is greater than the preset gas pressure threshold P for stopping the replenishment of inert gas. d When this occurs, the solenoid valve (280) of the gas storage cylinder is closed; And / or, the main controller (400) is configured to, when the temperature sensor detects that the temperature inside the battery compartment (100) is higher than a preset battery compartment internal temperature threshold T, m When the smoke sensor detects that the smoke level inside the battery compartment (100) is higher than a preset smoke concentration, it controls the fire extinguishing solenoid valve (320) to open; when the temperature sensor detects that the temperature inside the battery compartment (100) is not higher than a preset battery compartment internal temperature threshold T, it controls the fire extinguishing solenoid valve (320) to open. m When the smoke sensor detects that the smoke level inside the battery box (100) has not reached the preset smoke concentration, it controls the fire extinguishing solenoid valve (320) to close. And / or, the main controller (400) is used to record the time required before and after the gas pressure sensor detects the replenishment of inert gas, and when the recording time is less than the preset pressure drop time, it sends a prompt signal to the external prompting device; And / or, the main controller (400) is configured to, when the gas pressure sensor detects that the gas pressure inside the battery compartment (100) is higher than a preset pressure threshold P for opening the exhaust solenoid valve. n When the gas pressure sensor detects that the gas pressure inside the battery compartment (100) is less than the preset pressure threshold P for opening the exhaust solenoid valve, the gas pressure sensor controls the exhaust solenoid valve to open. n At that time, the exhaust solenoid valve (170) is closed.

3. The power battery fire prevention and extinguishing system according to claim 1, characterized in that, A filter cup (230) is provided between the air intake solenoid valve (220) and the gas generating device (240) for filtering the gas in the auxiliary gas cylinder (210) of the device; And / or, the inert gas control unit further includes an air compressor, a condenser and a dryer, wherein the air compressor is connected to the equipment auxiliary gas cylinder (210) in sequence through the condenser and the dryer; And / or, the gas generating device (240) is an air membrane separator nitrogen generator.

4. The power battery fire prevention and extinguishing system according to claim 1, characterized in that, The inert gas control unit also includes a gas cylinder pressure sensor (290) for measuring the inert gas pressure value in the gas cylinder (260); The gas cylinder pressure sensor (290) is electrically or signal-connected to the main controller (400). The main controller (400) is also used to determine whether to control the air intake solenoid valve (220) to open based on the inert gas pressure value in the gas cylinder (260).

5. The power battery fire prevention and extinguishing system according to claim 1, characterized in that, The extinguishing agent (313) in the fire extinguishing device (310) is stored at atmospheric pressure, and the fire extinguishing solenoid valve (320) of the fire extinguishing device (310) is connected to the outlet of the auxiliary gas cylinder (210). And / or, a fire extinguishing check valve (330) is connected in series on the pipeline between the fire extinguishing agent outlet (314) of the fire extinguishing device (310) and the air inlet (120) of the battery box (100).

6. The power battery fire prevention and extinguishing system according to claim 1, characterized in that, The number of battery boxes (100) is multiple.

7. A method for fire prevention and extinguishing of power batteries, characterized in that, The method of using the power battery fire prevention and extinguishing system according to claim 4 includes: The gas pressure data of the gas storage cylinder (260), the gas pressure, temperature and smoke data inside the battery box (100), and the oxygen concentration and gas humidity data in the exhaust of the battery box (100) are received respectively. In the fire suppression control logic, when the gas temperature inside the battery box (100) is higher than the preset battery box internal temperature threshold T... m When the smoke concentration is higher than the preset smoke concentration, power is supplied to the fire extinguishing solenoid valve (320). When the gas pressure inside the battery box (100) is higher than the preset pressure threshold P for opening the exhaust solenoid valve, power is supplied to the fire extinguishing solenoid valve. n When the exhaust solenoid valve (170) is powered, and the gas temperature inside the battery box (100) is lower than the preset battery box internal temperature threshold T, the power supply is applied. m Furthermore, when the smoke data is lower than the preset smoke concentration, the power is cut off to the fire extinguishing solenoid valve (320) and the exhaust solenoid valve (170); In the inert gas control logic, when the gas pressure inside the battery box (100) is less than the preset gas pressure threshold P at the start of inert gas replenishment... c Or, the oxygen concentration data in the exhaust of the battery box (100) is greater than or equal to the preset oxygen concentration C inside the battery box. m Or the gas humidity data is greater than or equal to the preset internal gas humidity H of the battery box. m When the gas cylinder solenoid valve (280) and the exhaust solenoid valve (170) are powered, and the oxygen concentration data in the exhaust of the battery box (100) is less than or equal to the preset oxygen concentration C inside the battery box, the power supply is applied. m Furthermore, the gas humidity data is less than or equal to the preset internal gas humidity H of the battery box. m When the exhaust solenoid valve (170) is de-energized, and the gas pressure inside the battery box (100) exceeds the preset threshold P for stopping the replenishment of inert gas, the gas pressure inside the battery box will be de-energized. d When the gas cylinder solenoid valve (280) is de-energized, the time required for the battery box (100) to replenish inert gas is recorded. When the required time is less than the preset pressure drop time, an alert signal is sent to the external alert device. In the gas production control logic, when the gas pressure data of the gas storage cylinder (260) is less than the preset gas pressure threshold P of the gas storage cylinder when gas production starts. a When the gas pressure data of the gas storage cylinder (260) is greater than the preset gas pressure threshold P when gas production stops, the gas supply solenoid valve (220) is powered. b At this time, the intake solenoid valve (220) is de-energized.

8. The method for preventing and extinguishing fires in power batteries according to claim 7, characterized in that, The fire extinguishing control logic, the inert gas control logic, and the gas generation control logic are three independent logic methods that do not affect each other.

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