Power battery prevention and control fire extinguishing system and method

Abstract

According to the power battery prevention and control fire extinguishing system and method, a detector assembly is additionally arranged in a battery box, and an oxygen concentration and humidity sensor, a second one-way throttling assembly and an exhaust electromagnetic valve are arranged on an exhaust pipeline. And the inert gas prevention and control unit is used for introducing high-purity inert gas into the battery box, so that a positive pressure environment in the battery box is kept, external air is prevented from entering the battery box, and a flame-retardant effect is achieved. When thermal runaway occurs in the battery box, a fire extinguishing agent is injected into the battery box through the fire extinguishing unit, the temperature in the battery box is reduced, and the chain reaction of the battery due to too high temperature in the thermal runaway process is prevented. The main control unit can control opening and closing of the electromagnetic valves according to signals of the sensors. Under normal conditions, the main control unit controls the inert gas prevention and control unit to work, and the fire extinguishing unit performs monitoring. When it is monitored that the temperature in the battery box is too high or smoke exists, the main control unit controls the fire extinguishing unit to start working, and the reliability and feasibility of system prevention and control fire extinguishing can be effectively improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power battery protection systems, and in particular relates to a power battery fire prevention and control system and method. Background Art

[0002] As the core component of power equipment, power batteries are receiving more and more attention for their safety performance. How to improve the safety of power batteries and avoid thermal runaway of power batteries has become an urgent problem to be solved by those skilled in the art.

[0003] The traditional method is to install a dry powder fire extinguisher outside the battery box, and when the power battery burns due to thermal runaway, the dry powder fire extinguishing agent is sprayed into the battery box to extinguish the fire. However, this method can only provide passive protection after the power battery spontaneously ignites due to thermal runaway, and cannot actively prevent the spontaneous combustion of the power battery in advance, thereby reducing the probability of thermal runaway of the power battery. To address this problem, some existing methods control the oxygen concentration inside the battery box within a certain range by filling nitrogen into the battery box, thereby preventing the power battery from spontaneously igniting due to thermal runaway. In addition, when the power battery has thermal runaway, an external fire extinguishing agent is sprayed into the battery box to extinguish the flame. However, this existing method still has the following three problems:

[0004] 1. The gas replacement efficiency inside the battery box is low: The existing method is to install a nozzle for delivering nitrogen on the outer shell of the battery box, inject nitrogen into the battery box through the pipeline, and rely on the pressure relief function of the battery box itself to discharge the internal gas before filling the battery box with nitrogen. Therefore, multiple replacements are required to control the oxygen concentration inside the battery box within a certain range, thereby playing a flame retardant role. In actual applications, the pressure relief process of the battery box itself is relatively slow and lasts for a long time, and the replacement efficiency of the gas inside the battery box is low;

[0005] 2. The explosion-proof valve exacerbates the battery reaction after it is opened: When a fire occurs in the battery box, the existing technology suppresses the fire by spraying fire extinguishing agent into the battery box. However, the injection of a large amount of fire extinguishing agent will cause a sharp increase in the pressure inside the battery box. When the pressure reaches a certain value, the explosion-proof valve of the battery box will automatically open to release the pressure. At this time, the inside of the battery box will change from the originally closed inert gas environment to an open state. After the outside air enters the battery box, it may exacerbate the combustion reaction of the battery, and even cause the fire inside the battery box to spread to the outside, causing greater losses to people's lives and property;

[0006] 3. Failure of pressure reduction in fire extinguishing device: When a fire occurs in a battery box due to thermal failure of the battery, the existing method is to extinguish the flame by spraying fire extinguishing agent into the battery box, and most fire extinguishing agents are stored at high pressure. In actual applications, the pressure in the tube of the fire extinguishing device will drop as the storage time increases. After long-term storage, the fire extinguishing agent may not be sprayed out due to the drop in pressure inside the device, which poses certain safety hazards.

[0007] Therefore, how to improve the reliability and feasibility of power battery fire prevention and control systems and methods is an urgent problem to be solved by technical personnel in this field. Summary of the invention

[0008] The purpose of the present invention is to provide a power battery fire prevention and control system and method, which can effectively improve the reliability and feasibility of the system fire prevention and control.

[0009] In order to solve the above technical problems, the present invention provides a power battery fire prevention and control system, comprising:

[0010] A battery box, with a power battery and a detector assembly built in, the detector assembly including a gas pressure sensor, a temperature sensor and a smoke sensor for monitoring the gas pressure value, temperature value and smoke value inside the battery box, the battery box is provided with an air inlet, an exhaust port and an explosion-proof valve, the exhaust port of the battery box is provided with an exhaust duct, and the exhaust duct is provided with an oxygen concentration and humidity sensor, a second one-way throttling assembly and an exhaust solenoid valve in sequence;

[0011] An inert gas prevention and control unit, comprising a gas cylinder for storing inert gas, a first one-way throttling assembly and a gas cylinder solenoid valve, wherein the gas cylinder is connected to the gas inlet of the battery box through the first one-way throttling assembly and the gas cylinder solenoid valve in sequence;

[0012] A fire extinguishing unit, comprising a fire extinguishing device, wherein the fire extinguishing device has a cavity, wherein a piston is movably disposed in the cavity, wherein the piston divides the cavity into an air cavity and a medium cavity for storing a fire extinguishing agent, wherein an air inlet on the fire extinguishing device is connected to the air cavity for introducing compressed gas, wherein a fire extinguishing solenoid valve is disposed on the air inlet, wherein a fire extinguishing agent outlet on the fire extinguishing device is connected to the medium cavity, and wherein the fire extinguishing agent outlet is connected to an 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 cylinder solenoid valve and the fire extinguishing solenoid valve.

[0014] Optionally, in the above-mentioned power battery fire prevention and control system, the main controller is used to control the gas storage bottle 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 inside the battery box when starting to replenish inert gas, or 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 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 controlled to be closed and the gas storage bottle solenoid valve is controlled to be opened; when the gas pressure sensor detects that the gas pressure inside the battery box is greater than the preset gas pressure threshold inside the battery box when the inert gas is stopped from being replenished, the gas storage bottle solenoid valve is controlled to be closed;

[0016] And / or, the main controller is used 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; 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 does not reach a preset smoke concentration, control the fire extinguishing solenoid valve to close;

[0017] And / or, the main controller is used to record the time required for replenishing the inert gas detected by the gas pressure sensor, and when the recorded time is less than the preset pressure drop time, send a prompt signal to the external prompt device;

[0018] And / or, the main controller is used 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 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 also includes a gas making device and a third one-way throttling assembly, the gas making device is provided with an air inlet, a first air outlet and a second air outlet, the air inlet of the gas making device is used to introduce compressed air, the first air outlet of the gas making device is connected to the air inlet of the gas storage bottle, and the second air outlet of the gas making device is used to discharge residual gas.

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

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

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

[0023] And / or, the gas making device is an air membrane separation nitrogen making machine.

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

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

[0026] Optionally, in the above-mentioned power battery fire prevention and control system, the fire extinguishing agent in the fire extinguishing device is stored at normal 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 fire extinguishing one-way valve is connected in series on the pipeline between the fire 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 control system, there are multiple battery boxes.

[0029] The present invention further provides a power battery fire prevention and control method, which uses the power battery fire prevention and control system in the above specific embodiment. The method includes:

[0030] Respectively receive the detected gas pressure data of the gas cylinder, the gas pressure, temperature and smoke data inside the battery box, and the oxygen concentration and gas humidity data in the exhaust gas of the battery box;

[0031] In the fire extinguishing 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 extinguishing solenoid valve is powered, and 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, and 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 extinguishing solenoid valve and the exhaust solenoid valve are powered off;

[0032] In the inert gas control logic, when the internal gas pressure data of the battery box is less than the preset internal gas pressure threshold of the battery box when the inert gas is replenished, or the oxygen concentration data in the exhaust gas of the battery box is greater than or equal to the preset internal oxygen concentration of the battery box, or the gas humidity data is greater than or equal to the preset internal gas humidity of the battery box, the gas cylinder solenoid valve and the exhaust solenoid valve are powered; when the oxygen concentration data in the exhaust gas of the battery box is less than or equal to the preset internal oxygen concentration of the battery box, and the gas humidity data is less than or equal to the preset internal gas humidity of the battery box, the exhaust solenoid valve is powered off; when the internal gas pressure data of the battery box is greater than the preset internal gas pressure threshold of the battery box when the inert gas is stopped, the gas cylinder solenoid valve is powered off, and the time required before and after the battery box is replenished with inert gas is recorded; when the required time is less than the preset pressure drop time, a prompt signal is sent to an external prompt device;

[0033] In the gas production control logic, when the gas pressure data of the gas cylinder is less than the preset gas pressure threshold of the gas cylinder when starting gas production, the air intake solenoid valve is powered on; when the gas pressure data of the gas cylinder is greater than the preset gas pressure threshold of the gas cylinder when stopping gas production, the air intake solenoid valve is powered off.

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

[0035] The present invention provides a power battery fire prevention and control system and method, which has the following beneficial effects:

[0036] By installing a gas pressure sensor, a temperature sensor and a smoke sensor inside the battery box, an oxygen concentration humidity sensor, a second one-way throttling assembly and an exhaust solenoid valve are sequentially arranged on the exhaust pipe of the battery box. The gas cylinder of the inert gas prevention and control unit is used to pass high-purity nitrogen into the battery box, and the gas cylinder solenoid valve is used to control the connection and disconnection between the gas cylinder and the battery box, so as to maintain the positive pressure environment inside the battery box, prevent the outside air from entering the battery box, and then play a flame retardant role to prevent combustion and explosion caused by thermal runaway of the battery. When the power battery thermal runaway occurs inside the battery box, the fire extinguishing unit is used to inject cooling and fire extinguishing agents into the battery box to reduce the temperature inside the battery box and prevent the battery from chain reaction due to excessive temperature during thermal runaway. The main control unit can control the opening and closing of each solenoid valve according to the signals of each sensor. Under normal circumstances, the main control unit controls the inert gas prevention and control unit to work, and the fire extinguishing unit to monitor. When it is detected that the temperature inside the battery box is too high or there is smoke, the main control unit controls the fire extinguishing unit to start working. Through the cooperation of the battery box, inert gas prevention and control unit, fire extinguishing unit and main control unit, the reliability and feasibility of the system's fire prevention and control can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0038] Figure 1 A front view of a battery box provided by an embodiment of the present invention;

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

[0040] Figure 3-Figure 4 An architectural diagram of a power battery fire prevention and control system provided by an embodiment of the present invention;

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

[0042] Figure 6 A control logic flow chart of a power battery fire prevention and control method provided in an embodiment of the present invention.

[0043] In the above picture:

[0044] 100-battery box; 110-detector assembly; 120-air inlet; 130-exhaust outlet; 140-explosion-proof valve; 150-oxygen concentration and humidity sensor; 160-second one-way throttling assembly; 170-exhaust solenoid valve;

[0045] 210-equipment auxiliary gas cylinder; 220-intake solenoid valve; 230-filter cup; 240-gas making device; 250-third one-way throttling assembly; 260-gas storage bottle; 270-first one-way throttling assembly; 280-gas storage bottle solenoid valve; 290-gas storage bottle pressure sensor;

[0046] 310-fire extinguishing device; 311-air inlet; 312-piston; 313-fire extinguishing agent; 314-fire extinguishing agent outlet; 320-fire extinguishing solenoid valve; 330-fire extinguishing one-way valve;

[0047] 400-main controller;

[0048] exist Figure 3-Figure 4 In the figure, the straight line with an arrow indicates the flow direction of gas or fire extinguishing agent when the power battery fire prevention and control system is working; the dotted line indicates the communication line and power supply line between the electronic components and the main controller. It should be noted that the "intake solenoid valve 220", "fire extinguishing solenoid valve 320", "gas cylinder solenoid valve 280" and "exhaust solenoid valve 170" are all the same device. The figure only distinguishes each solenoid valve according to its role in the system, and the solenoid valves used in the system are all normally closed solenoid valves, that is, the solenoid valve is closed when the solenoid valve is not powered under normal circumstances, and the solenoid valve is open when the solenoid valve is powered; the "third one-way throttling component 250", "first one-way throttling component 270" and "second one-way throttling component 160" are also the same device, and "first", "second" and "third" are only used to distinguish one entity from another, not the order between the entities in the device. DETAILED DESCRIPTION

[0049] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0050] The core of the present invention is to provide a power battery fire prevention and control system and method, which can effectively improve the reliability and feasibility of the system fire prevention and control.

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

[0052] The application fields of power batteries are very wide, from traditional automobiles, motorcycles and industrial power systems to emerging electric aviation, low-altitude aircraft and electric ships, etc., which are constantly expanding. With the advancement of technology and changes in market demand, the application prospects of power batteries will be broader. Therefore, the power equipment used by the power batteries involved in this case can be equipment with certain power, such as new energy vehicles, electric aviation, low-altitude aircraft, electric ships, robots, etc., which are equipped with power batteries inside to provide power for the equipment.

[0053] Specifically, please refer to Figure 1-Figure 6 , a power battery fire prevention and control system and method provided by the present invention includes: 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 has a built-in 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 is used to detect the gas pressure inside the battery box 100, the temperature sensor is used to detect the temperature value inside the battery box 100, and the smoke sensor is used to monitor the smoke value inside the battery box 100. The battery box 100 is provided with an air inlet 120, an exhaust port 130 and an explosion-proof valve 140. The exhaust port 130 of the battery box 100 is connected to the exhaust pipe. The exhaust pipe is sequentially provided with an oxygen concentration and humidity sensor 150 (which can be two sensors for detecting oxygen concentration and exhaust gas humidity respectively, or an integrated structure after the two sensors are integrated), a second one-way throttling assembly 160 and an exhaust solenoid valve 170. Specifically, the exhaust solenoid valve 170 can be arranged at the end of the exhaust pipe. The exhaust solenoid valve 170 is used to control whether the gas inside the battery box 100 is discharged. The battery box 100 also includes an oxygen concentration humidity sensor 150 and a second one-way throttling component 160 between the exhaust port 130 and the exhaust solenoid valve 170. The oxygen concentration humidity sensor 150 is used to measure the oxygen concentration and gas humidity in the gas. Since the current oxygen concentration sensor technology is relatively mature and the ratio of a certain inert gas (such as nitrogen) to the oxygen content in the air is fixed, the device uses a method of measuring the 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 pipeline from the exhaust port 130 of the battery box 100 to the exhaust solenoid valve 170, to prevent the air from entering the battery box 100 through the exhaust pipeline when the exhaust solenoid valve 170 is opened, and the excessive gas flow in the exhaust pipeline damages the oxygen concentration humidity sensor 150.

[0055] It should be noted that the gas at the air inlet 120 and the exhaust port 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, and the gas at the exhaust port 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 pass the obtained high-purity inert gas into the battery box 100, and the exhaust port 130 is used to discharge the gas inside the battery box 100 to the outside, so as to improve the replacement efficiency of the gas 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, so as to determine whether the battery box 100 has thermal runaway, and then control whether to fill the battery box 100 with inert gas, discharge fire extinguishing agent, etc.

[0056] It should also be noted that the air inlet 120, the exhaust port 130 and the explosion-proof valve 140 on the battery box 100 can be installed at any place of the battery box 100, and can be adaptively selected according to actual needs, such as Figure 1 and Figure 2 As shown, the front side of the battery box 100 is provided with an air inlet 120 and an explosion-proof valve 140, and the rear side of the battery box 100 is provided with an exhaust port 130. The detector assembly 110 is arranged inside the battery box 100. Figure 1 Only the specific position of the detector assembly 110 is shown in the figure. In fact, the built-in detector assembly 110 cannot be seen from the outside of the battery box 100.

[0057] The inert gas prevention and control unit is used to pass high-purity inert gas into the battery box 100, so as to maintain the positive pressure environment inside the battery box 100, prevent outside air from entering the battery box 100, and then play a flame retardant role to prevent combustion, explosion and other situations caused by thermal runaway of the battery. The inert gas prevention and control unit specifically includes a gas cylinder 260 for storing inert gas, a first one-way throttling component 270 and a gas cylinder solenoid valve 280. The gas cylinder 260 is connected to the air inlet 120 of the battery box 100 through the first one-way throttling component 270 and the gas cylinder solenoid valve 280 in turn. The gas cylinder 260 is used to store the inert gas produced by the gas production device 240, and two gas ports are arranged on the bottle, namely the air inlet and the air outlet. A first one-way throttling assembly 270 and a gas cylinder solenoid valve 280 are arranged between the gas outlet of the gas cylinder 260 and the gas inlet 120 of the battery box 100, wherein the function of the first one-way throttling assembly 270 is consistent with that of the second one-way throttling assembly 160 (third one-way throttling assembly 250), that is, to control the flow rate and flow direction of the gas in the pipeline, and its function is to adjust the flow rate of the high-pressure gas flowing out of the gas outlet of the gas cylinder 260 to prevent the excessive flow of the inert gas from damaging the power battery in the battery box 100 and the detector assembly 110. The gas cylinder solenoid valve 280 is used to control the on-off of the gas pipeline between the gas outlet of the gas cylinder 260 and the gas inlet 120 of the battery box 100.

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

[0059] The fire extinguishing unit is used to inject a cooling fire extinguishing agent 313 into the battery box 100 when a power battery thermal runaway occurs inside the battery box 100, so as to reduce the temperature inside the battery box 100 and prevent the battery from chain reacting due to excessive temperature during thermal runaway. Under normal circumstances, the inert gas prevention and control unit works and the fire extinguishing unit monitors. When it is detected that the temperature inside the battery box 100 is too high or there is smoke, the fire extinguishing unit starts to work. The fire extinguishing unit specifically includes a fire extinguishing device 310, which has a cavity inside the fire extinguishing device 310, and a piston 312 is movably arranged in the cavity. The piston 312 divides the cavity into an air cavity and a medium cavity for storing the fire extinguishing agent 313. The air inlet 311 on the fire extinguishing device 310 is connected to the air cavity for introducing compressed gas. The air inlet 311 is provided with a fire extinguishing solenoid valve 320, and the fire extinguishing agent outlet 314 on the fire extinguishing device 310 is connected to the medium cavity, and the fire extinguishing agent outlet 314 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 the gas pressure sensor, the temperature sensor, the smoke sensor, the oxygen concentration and humidity sensor 150, the exhaust solenoid valve 170, the gas cylinder solenoid valve 280 and the fire extinguishing solenoid valve 320 respectively.

[0061] The power battery fire prevention and control system provided by this solution is provided with an air inlet 120 and an exhaust port 130 by installing a gas pressure sensor, a temperature sensor and a smoke sensor inside the battery box 100, and an oxygen concentration humidity sensor 150, a second one-way throttling assembly 160 and an exhaust solenoid valve 170 are sequentially arranged on the exhaust pipe connected to the exhaust port 130. The gas cylinder 260 of the inert gas prevention and control unit is used to pass high-purity inert gas into the battery box 100, and the gas cylinder solenoid valve 280 is used to control the connection and disconnection between the gas cylinder 260 and the battery box 100, so as to maintain the positive pressure environment inside the battery box 100, prevent the outside air from entering the battery box 100, and then play a flame retardant role to prevent combustion, explosion and other situations caused by thermal runaway of the battery. When thermal runaway of the power battery occurs inside the battery box 100, the fire extinguishing unit is used to inject a cooling fire extinguishing agent 313 into the battery box 100 to reduce the temperature inside the battery box 100 and prevent the battery from chain reacting due to excessive temperature during thermal runaway. The main control unit can control the opening and closing of each solenoid valve according to the signals of each sensor. Under normal circumstances, the main control unit controls the inert gas prevention and control unit to work, and the fire extinguishing unit monitors. When it is detected that the temperature inside the battery box 100 is too high or there is smoke, the main control unit controls the fire extinguishing unit to start working.

[0062] Based on the above configuration, compared with the prior art, which can only ensure that the concentration of the inert gas injected into the battery box meets the flame retardant standard, but cannot ensure whether the concentration of the inert gas inside the battery box meets the flame retardant standard, and only relies on the natural outward permeation of the gas inside the battery box until the pressure drops to the standard pressure value, and there is no gas detection device, the beneficial effects of this solution are:

[0063] 1. When the power battery is in normal use, by detecting the gas pressure value, oxygen concentration and humidity inside the battery box 100, it is determined whether it is necessary to add inert gas inside the battery box 100, so that the concentration of inert gas in the gas inside the battery box 100 can be ensured to meet the flame retardant standard in real time;

[0064] 2. When it is necessary to add inert gas to the battery box 100, the exhaust solenoid valve 170 is controlled to open until the gas discharged from the battery box 100 meets the oxygen concentration and humidity standards, thereby accelerating the gas replacement process inside the battery box 100, improving the gas replacement efficiency inside the battery box, and improving the safety of the power battery fire prevention and control system.

[0065] 3. When the pressure value inside the battery box 100 is higher than the preset pressure threshold P for the exhaust solenoid valve to open nWhen the fire extinguishing agent is sprayed into the battery box 100, the main controller 400 controls the exhaust solenoid valve 170 to open, thereby avoiding a sharp increase in the internal pressure of the battery box 100, causing the explosion-proof valve 140 to open automatically, destroying the inert gas environment inside the battery box 100, aggravating the thermal runaway of the battery, and even causing the fire inside the battery box to spread to the outside of the battery box, thereby increasing safety.

[0066] 4. Since it is necessary to maintain a positive pressure inside the battery box 100 after the inert gas is filled into the battery box 100, under this condition, the air tightness of the battery box 100 gradually deteriorates with the passage of time. The present invention monitors the air tightness of the battery box by recording the time it takes for the air pressure inside the battery box 100 to drop after the inert gas is filled into the battery box 100. As time goes by, when the air tightness of the battery box deteriorates, the situation can be fed back to the relevant personnel in a timely manner, so that the relevant personnel can perform maintenance on the battery box. This avoids the potential safety hazard of water or other liquids entering the battery box due to the deterioration of the air tightness of the battery box.

[0067] Through the cooperation among the battery box 100, the inert gas prevention and control unit, the fire extinguishing unit and the main control unit, the reliability and feasibility of the system fire prevention and control 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 that the gas pressure P2 inside the battery box is less than the preset gas pressure threshold P when the gas pressure sensor starts to replenish the inert gas. c , or the oxygen concentration C at the battery box exhaust port detected by the oxygen concentration humidity sensor 150 is greater than or equal to the preset battery box internal oxygen concentration C m , or the gas humidity H at the battery box exhaust port is greater than or equal to the preset battery box internal gas humidity H m When the oxygen concentration C at the exhaust port of the battery box detected by the oxygen concentration and humidity sensor 150 is less than or equal to the preset oxygen concentration C inside the battery box, the inert gas needs to be injected into the battery box 100 to control the gas cylinder solenoid valve 280 and the exhaust solenoid valve 170 to open; m , and the gas humidity H at the battery box exhaust port is less than or equal to the preset battery box internal gas humidity H m When the gas pressure sensor detects that the gas pressure P2 inside the battery box is greater than the preset gas pressure threshold P2 when the inert gas is stopped, the gas pressure sensor detects that the gas pressure P2 inside the battery box is greater than the preset gas pressure threshold P2 when the inert gas is stopped. d When the inert gas is injected into the battery box 100, it is necessary to stop injecting the inert gas into the battery box 100 and control the gas cylinder solenoid valve 280 to close.

[0070] It can be understood that when the gas permeation inside the battery box 100 causes the internal pressure P2 of the battery box 100 to drop to the preset gas pressure threshold P when the inert gas is replenished. c , or the oxygen concentration C at the battery box exhaust port detected by the oxygen concentration humidity sensor 150 is greater than or equal to the preset battery box internal oxygen concentration C m , or the gas humidity H at the battery box exhaust port is greater than the preset battery box internal gas humidity H m When the main controller 400 controls the gas cylinder solenoid valve 280 and the exhaust solenoid valve 170 to open, the inert gas in the gas cylinder 260 flows out from the gas outlet of the gas cylinder 260, and is filled into the battery box 100 from the gas inlet 120 of the battery box 100 through the first one-way throttling assembly 270 and the gas cylinder solenoid valve 280. This stage can be regarded as the first stage. When the gas at the exhaust port 130 does not meet the standard, the inert gas is injected into the battery box 100. At this time, the exhaust solenoid valve 170 is in an open state, so the gas pressure value inside the battery box 100 will not increase much. The purpose at this time is to discharge the original gas inside the battery box as much as possible by injecting inert gas into the battery box 100.

[0071] After the main controller 400 controls the gas cylinder solenoid valve 280 and the exhaust solenoid valve 170 to open, the oxygen concentration of the gas discharged from the exhaust port 130 is reduced due to the injection of inert gas. When the oxygen concentration C of the exhaust port 130 on the battery box 100 detected by the oxygen concentration humidity sensor 150 is less than or equal to the preset oxygen concentration C inside the battery box, m , and the gas humidity H at the exhaust port 130 on the battery box 100 is less than or equal to the preset gas humidity H inside the battery box m When the main controller 400 controls the exhaust solenoid valve 170 to close, the inert gas is continuously injected into the battery box 100, which will increase the gas pressure inside the battery box 100. When the gas pressure inside the battery box 100 increases to the preset gas pressure threshold P when the inert gas is stopped, the gas pressure inside the battery box 100 is reduced to the preset gas pressure threshold P when the inert gas is stopped. d When the inert gas is filled to the battery box 100, the main controller 400 controls the gas cylinder solenoid valve 280 to close and stops filling the battery box 100 with inert gas. 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, which 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, the exhaust solenoid valve 170 is controlled to open, and the battery box 100 is replenished with inert gas while exhausting the gas simultaneously, thereby accelerating the process of replacing the gas inside the battery box 100 and improving the replacement efficiency of the gas inside the battery box 100.

[0073] Method 2: The main controller 400 is used to detect that the temperature T inside the battery box 100 is higher than the preset battery box internal temperature threshold T m , or when the smoke sensor detects that the smoke value inside the battery box 100 reaches a preset smoke concentration, it indicates that the temperature inside the battery box 100 is too high or there is smoke, and the fire extinguishing solenoid valve 320 is controlled to open; when the temperature sensor detects that the temperature T inside the battery box 100 is not higher than the preset battery box internal temperature threshold T m , or when the smoke sensor detects that the smoke value inside the battery box 100 does not reach the preset smoke concentration, it indicates that the inside of the battery box 100 is in a normal working state, and the fire extinguishing solenoid valve 320 is controlled to be closed.

[0074] When it is detected that the temperature T inside the battery box 100 is too high or there is smoke, the main controller 400 controls the fire extinguishing solenoid valve 320 to open, and the fire extinguishing unit starts to work, that is, the air inlet on the fire extinguishing device 310 introduces compressed gas into the air cavity, and the compressed gas pushes the piston 312 to move toward the medium cavity, and the fire extinguishing agent 313 enters the air inlet 120 of the battery box 100 from the fire extinguishing agent outlet 314 to extinguish the fire. Under normal circumstances, the inert gas prevention and control unit works, the main controller 400 controls the fire extinguishing solenoid valve 320 to close, and the fire extinguishing unit monitors.

[0075] Since thermal runaway of a battery is often accompanied by an increase in temperature and the generation of smoke, the temperature sensor and the smoke sensor are used to detect whether the battery inside the battery box 100 has thermal runaway, and then the main controller 400 controls whether to inject the 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 gas pressure inside the battery box changes from P d Down to P c When the recorded time is less than the preset pressure drop time (the preset gas pressure inside the battery box is P d Down to P c When the time taken is N), a prompt signal is sent to the external prompt device.

[0077] After the battery box 100 is replenished with inert gas, the air tightness of the battery box 100 is monitored by recording the time for the internal air pressure of the battery box 100 to drop. When the air pressure drop time is too short, it means that the air tightness of the battery box 100 has deteriorated, reminding the maintenance personnel to perform maintenance.

[0078] Mode 4: The main controller 400 is used to detect that the gas pressure inside the battery box 100 reaches a preset pressure threshold P for opening the exhaust solenoid valve. nWhen the gas pressure sensor detects that the gas pressure inside the battery box 100 is less than the preset pressure threshold P for opening the exhaust solenoid valve, the exhaust solenoid valve 170 is controlled to open; n When the exhaust solenoid valve 170 is controlled to be closed.

[0079] It should be noted that when the gas pressure inside the battery box 100 is higher than the pressure threshold P at which the explosion-proof valve automatically opens, m In order to avoid the possibility that the explosion-proof valve 140 may be automatically opened when the fire extinguishing agent is sprayed into the battery box 100, a preset pressure threshold P for opening the exhaust solenoid valve is specially set. n , and P n The value is greater than the preset gas pressure threshold P inside the battery box when the inert gas is stopped. d , less than the pressure threshold P of the explosion-proof valve that automatically opens m When the gas pressure inside the battery box 100 is detected to be higher than P n When the main controller 400 controls the exhaust solenoid valve 170 to open, thereby preventing the gas pressure inside the battery box 100 from being higher than the pressure threshold P at which the explosion-proof valve automatically opens. m This causes the explosion-proof valve to open automatically. n The value is between the preset gas pressure threshold P of the battery box when the inert gas is stopped. d and the threshold value P for the explosion-proof valve to open automatically m Between (P d <P n <P m ).

[0080] By setting an opening threshold for the exhaust solenoid valve 170 , it is prevented that the explosion-proof valve 140 is automatically opened when the fire extinguishing agent is sprayed into the battery box 100 , and that external gas enters the battery box 100 to aggravate the battery combustion reaction.

[0081] In a specific embodiment, Figure 4 As shown, the inert gas prevention and control unit also includes a gas making device 240 for making inert gas and a third one-way throttling assembly 250. The gas making device 240 is a one-inlet and two-outlet structure, which produces and purifies the required inert gas through a series of physical and chemical processes. The gas making device 240 is respectively provided with an air inlet, a first air outlet and a second air outlet. The air inlet of the gas making device 240 is used to introduce compressed air. The first air outlet of the gas making device 240 is connected to the air inlet of the gas storage bottle 260, so as to facilitate the storage of the produced inert gas in the form of high-pressure gas in the gas storage bottle 260. The second air outlet of the gas making device 240 is used to discharge the remaining gas.

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

[0083] It is understandable that the "first one-way throttling assembly 270", "the second one-way throttling assembly 160" and "the third one-way throttling assembly 250" can adopt the same structure or different structures. Each of the above-mentioned one-way throttling assemblies can be a one-way throttling valve to control the flow direction and flow rate, and can also be replaced by a combination of a one-way valve and a pressure stabilizing structure, which will not be described in detail here.

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

[0085] Among them, the equipment auxiliary gas cylinder 210 is a gas storage cylinder provided by the power equipment itself, and the air inlet of the gas making device 240 is connected to the equipment auxiliary gas cylinder 210, and the equipment auxiliary gas cylinder 210 is used as the gas source; the air intake solenoid valve 220 is used to control whether compressed air enters the gas making device 240 to produce inert gas; the purpose of setting the third one-way throttling component 250 can also 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 making device 240 when the air intake solenoid valve 220 is closed.

[0086] In a specific embodiment, a filter cup 230 is provided between the air inlet solenoid valve 220 and the gas production device 240 for filtering the gas in the equipment auxiliary gas cylinder 210 to prevent small particle impurities in the gas from clogging and damaging the inert gas separation membrane in the gas production device.

[0087] The inert gas control unit also includes an air compressor, a condenser and a dryer. The air compressor is connected to the equipment auxiliary gas cylinder 210 through the condenser and the dryer in turn. When the power equipment is started, the air compressor of the power equipment starts to work, compresses the air and stores it in the auxiliary gas cylinder for use during the operation of the power equipment. A filter can also be set in front of the air compressor to filter dust particles in the air. A condenser and a dryer are set between the air compressor and the equipment auxiliary gas cylinder 210 to dehumidify the compressed air. This part of the device is not included in the Figure 3 and Figure 4 The gas stored in the equipment auxiliary gas cylinder 210 is compressed air that has been filtered and dried.

[0088] Of course, the equipment auxiliary gas cylinder 210 serving as the gas source may be replaced by an air compressor or an air pump, that is, compressed air may be provided directly by the air compressor or the air pump without the need to additionally set up the equipment auxiliary gas cylinder 210 as a storage device.

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

[0090] In particular, when nitrogen is used as the inert gas, the gas making device 240 is an air membrane separation nitrogen making machine, which obtains high-purity nitrogen by filtering.

[0091] The inert gas prevention and control unit further includes a gas cylinder pressure sensor 290 disposed in the gas cylinder 260 , which is used to measure the inert gas pressure P1 in the gas cylinder 260 and feed 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 according to the inert gas pressure P1 in the gas cylinder 260, so that the compressed air in the equipment auxiliary gas cylinder 210 enters the gas making device 240 to prepare the inert gas.

[0093] In a further embodiment, in order to avoid the safety hazard of pressure reduction and failure of fire extinguishing agent to be sprayed out due to high-pressure storage of fire extinguishing agent, the fire 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 equipment auxiliary gas cylinder 210.

[0094] Among them, the fire extinguishing agent 313 can use perfluorohexanone, etc. The fire extinguishing agent 313 is liquid at room temperature, easy to vaporize, can absorb a lot of heat after vaporization, is not easy to burn, can be used to extinguish the battery fire and will not pollute the battery surface; in addition, the ozone depletion potential (ODP) of perfluorohexanone is 0, the global greenhouse effect potential (GWP) is 1, and the atmospheric survival life (year) is 0.014 (5 days). Its fire extinguishing concentration is 4-6%, and the safety margin is relatively high. Of course, perfluorohexanone fire extinguishing agent is only one type of fire extinguishing agent, and other types of fire extinguishing agents can also be used as a substitute. The use of this type of fire extinguishing agent can quickly absorb the large amount of heat generated when the power battery is thermally runaway, thereby suppressing the thermal runaway of the power battery.

[0095] The fire extinguishing device 310 uses the equipment auxiliary gas cylinder 210 as the gas source, and pushes the fire extinguishing agent 313 to spray out by pushing the piston 312. The structure of the fire extinguishing device 310 is as follows: Figure 5 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 storage 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. The fire extinguishing solenoid valve 320 is used to control whether the gas in the equipment auxiliary gas cylinder 210 is passed into the fire extinguishing device 310, thereby pushing the piston 312 to spray the fire extinguishing agent 313 into the battery box 100.

[0096] A fire extinguishing one-way valve 330 is also provided 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. The fire extinguishing one-way valve 330 is used to control the one-way flow of gas and fire extinguishing agent 313, that is, the fire extinguishing agent 313 can only flow from the fire extinguishing agent outlet 314 of the fire extinguishing device 310 to the air inlet 120 of the battery box 100, thereby preventing the high-pressure inert gas in the gas cylinder from entering the fire extinguishing device 310 through the pipeline when the solenoid valve 280 of the gas cylinder is opened.

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

[0098] When it is necessary to replenish inert gas into the battery box 100, the gas cylinder solenoid valve 280 and the exhaust solenoid valve 170 are opened, and the high-pressure inert gas in the gas cylinder 260 flows out from the gas 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, while the gas in the battery box 100 is discharged into the air from the exhaust port 130 of the battery box 100 through 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 meet the standards, 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 internal air pressure of the battery box 100 reaches the preset value, and then closes the gas storage bottle solenoid valve 280 to complete the replenishment of the inert gas in 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 standards, and after the gas production device 240 produces inert gas once, the oxygen concentration and humidity sensor 150 detects that the gas concentration or humidity discharged from the battery box 100 still does not meet the standards, then the fault is reported. After the inert gas is replenished to the battery box 100, the gas cylinder solenoid valve 280 and the exhaust solenoid valve 170 are both 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 the gas pressure inside the battery box 100 drops below the inert gas replenishment standard, the main controller 400 controls the gas cylinder solenoid valve 280 and the exhaust solenoid valve 170 to open and replenish the inert gas to the battery box 100. The above process can ensure that the inert gas concentration in the gas inside the battery box meets the flame retardant standard in real time, and prevent combustion, explosion, etc. caused by thermal runaway of the power battery.

[0099] In addition, since the battery box 100 is filled with inert gas to create 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 the outside air or water from entering the battery box due to poor airtightness and causing safety hazards, a battery box airtightness failure alarm is set in the system. When the battery box airtightness is poor, an alarm can be sounded to notify maintenance personnel for maintenance. The method is as follows: after the inert gas is added to the battery box, the gas inside the battery box will penetrate until the internal air pressure of the battery box drops to the standard for adding inert gas, and then the battery box is filled with inert gas again (referred to as inflation); in the process from the completion of the last inflation to the start of the next inflation, the internal air pressure of the battery box is a pressure drop process, and since the pressure difference between the internal air pressure of the battery pack when the inflation starts and the internal air pressure of the battery pack when the inflation stops is a fixed value, the main controller 400 records the pressure drop time after each inflation of the battery box and compares it with the preset time value. When the pressure drop time of the battery box after a certain inflation is less than the preset time value, it means that the pressure inside the battery box drops too fast, that is, the air tightness of the battery box is significantly deteriorated. At this time, the main controller 400 issues an air tightness deterioration alarm, notifies the maintenance personnel to perform maintenance, and continues to inflate the battery box before performing maintenance.

[0100] When the temperature sensor and smoke sensor inside the battery box 100 detect that the temperature inside the battery box is too high or smoke appears inside the battery box, the main controller 400 controls the fire extinguishing solenoid valve 320 to open, and the high-pressure gas in the equipment auxiliary gas cylinder 210 enters the fire extinguishing device 310 to push the piston 312 to move, thereby pushing the cooling fire extinguishing agent 313 to enter the battery box 100 through the pipeline from the air inlet 120 of the battery box 100 to suppress the thermal runaway of the battery. At the same time, the pressure sensor inside the battery box 100 monitors the internal pressure of the battery box in real time. If the pressure inside the battery box 100 reaches a certain preset value P n (and P n Higher than the gas pressure threshold P inside the battery box when the inert gas is stopped d , below the pressure threshold P of the explosion-proof valve that automatically opens m), the main controller 400 controls the exhaust solenoid valve 170 to open and release the pressure of the battery box 100 to prevent the explosion-proof valve 140 from opening due to excessive pressure inside the battery box 100, causing outside air to enter the battery box to destroy the inert gas environment inside the battery box, aggravate the battery reaction, and even spread the fire to the outside. After the cooling fire extinguishing agent 313 is sprayed into the battery box 100, the temperature and smoke sensors inside the battery box 100 monitor the temperature and smoke inside the battery box. When the temperature drops and the smoke dissipates, the main controller 400 controls the fire extinguishing solenoid valve 320 and the exhaust solenoid valve 170 to close, and then the temperature and smoke sensors inside the battery box continue to monitor the inside of the battery box to prevent the battery from re-igniting.

[0101] In addition, the present solution also provides a power battery fire prevention and control method, which is characterized in that the power battery fire prevention and control system in the above specific embodiment is applied, and the method includes:

[0102] S100, respectively receive the detected gas pressure data of the gas 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; the above data come from the gas cylinder pressure sensor 290, the gas pressure sensor, the temperature sensor, the smoke sensor and the oxygen concentration and humidity sensor 150.

[0103] S200: In the fire extinguishing control logic, when the gas temperature data inside the battery box 100 is higher than the preset battery box internal temperature threshold T m , or when the smoke data is higher than the preset smoke concentration, the fire extinguishing solenoid valve 320 is powered to push the fire extinguishing agent 313 into the battery box 100. When the gas pressure data inside the battery box 100 is higher than the preset exhaust solenoid valve opening pressure threshold P n When the exhaust solenoid valve 170 is powered to exhaust the battery box 100, when the gas temperature data inside the battery box 100 is lower than the preset battery box internal temperature threshold T m When the smoke data is lower than the preset smoke concentration, the fire extinguishing solenoid valve 320 and the exhaust solenoid valve 170 are powered off;

[0104] S300: In the inert gas control logic, when the gas pressure data inside the battery box 100 is less than the preset gas pressure threshold P when the inert gas is replenished, c , or the oxygen concentration data in the exhaust gas 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 battery box internal gas humidity H mWhen the oxygen concentration data in the exhaust gas of the battery box 100 is less than or equal to the preset oxygen concentration C inside the battery box, the gas cylinder solenoid valve 280 and the exhaust solenoid valve 170 are powered to replace the gas in the battery box 100. m , and the gas humidity data is less than or equal to the preset battery box internal gas humidity H m When the exhaust solenoid valve 170 is powered off, the gas pressure data inside the battery box 100 is greater than the preset gas pressure threshold value P when the inert gas is stopped. d When the gas cylinder solenoid valve 280 is powered off, the time required for the battery box 100 to be replenished with inert gas is recorded (i.e., the gas pressure inside the battery box changes from P d Down to P c time), when the required time is less than the preset pressure drop time (the preset battery box internal gas pressure is P d Down to P c When 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 storage cylinder gas pressure threshold value P when starting gas production, a When the gas pressure data of the gas storage cylinder 260 is greater than the preset gas storage cylinder gas pressure threshold value P when gas production is stopped, the gas supply solenoid valve 220 is powered. b When the power is turned off, the air intake solenoid valve 220 is powered off.

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

[0107] Furthermore, in the gas production control logic, in order to avoid safety hazards, if the duration of a single nitrogen production exceeds the preset time M required for preparing an inert gas once, that is, the single opening time of the air intake solenoid valve 220 exceeds the preset time M required for preparing an inert gas once, the main controller 400 will force the air intake solenoid valve 220 to close, 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 control method using the above-mentioned power battery fire prevention and control system has the same beneficial effects, which will not be elaborated here.

[0109] In order to further illustrate the present invention, a power battery fire prevention and control system and method are described in detail below in conjunction with embodiments.

[0110] The power equipment in the following specific embodiment is a new energy vehicle, the inert gas filled in the battery box is nitrogen, and the number of battery boxes is two. The symbols and their corresponding explanations are shown in Table 1. The control logic flow chart corresponding to this embodiment is shown in Figure 6 shown. Figure 6 It includes fire extinguishing control logic S200, inert gas control logic S300 and gas production control logic S400. It should be noted that the above three logics do not affect each other. Figure 6 The above three logics are in parallel mode; in addition, the solenoid valves used in this system are all normally closed solenoid valves, which are closed when the power is off and open when the power is on. Figure 6 In the control logic flow shown, "solenoid valve power supply" means the solenoid valve is opened.

[0111] In the gas control logic S400, when the gas cylinder pressure sensor 290 detects that the gas pressure P1 of the gas cylinder is lower than the preset value P a When the main controller 400 controls the air inlet solenoid valve 220 to open, the compressed air in the auxiliary gas cylinder 210 enters the air inlet of the gas making device 240 through the pipeline to make nitrogen; the nitrogen outlet of the gas making device 240 is connected to the gas storage bottle 260, so the nitrogen produced is stored in the gas storage bottle 260 in the form of high-pressure gas. When the air pressure P1 of the gas storage bottle 260 reaches the preset value P b When the main controller 400 controls the air intake solenoid valve 220 to close, the compressed air in the equipment auxiliary gas cylinder 210 cannot enter the air inlet of the gas making device 240, and the gas making device 240 stops making nitrogen. In addition, to avoid potential safety hazards, if the single nitrogen making time exceeds 1 hour (M can be 60 minutes), that is, the single opening time of the air intake solenoid valve 220 exceeds 1 hour, the main controller 400 will force the air intake solenoid valve 220 to close, stop the nitrogen making of the gas making device 240, and report the fault code to the vehicle instrument display.

[0112] In the inert gas control logic S300, when the pressure sensors in the two battery boxes detect the internal gas pressures P 2,1 and P 2,2 There is a pressure value between them that is less than the preset nitrogen filling pressure P c , or the oxygen concentration and humidity sensors connected to the two battery boxes detect that the oxygen concentration C of the gas inside the two battery boxes is higher than the preset oxygen standard C m Or the gas humidity H is higher than the preset gas humidity H m When the main controller 400 controls the gas cylinder solenoid valve 280 and the exhaust solenoid valve 170 to open, the gases inside the two battery boxes are replaced until the oxygen concentration C in the gas discharged from the battery box is lower than the preset oxygen standard C m And the gas humidity H is lower than the preset gas humidity H mWhen the main controller 400 controls the exhaust solenoid valve 170 to close, the gas cylinder solenoid valve 280 continues to be in the open state, and nitrogen is filled into the two battery boxes; until the gas pressure inside the two battery boxes is P 2,1 and P 2,2 Reach the preset nitrogen filling stop standard P d At this time, the main controller 400 controls the gas cylinder solenoid valve 280 to close. At this time, the main controller 400 records the time t1 and t2 during the pressure drop process from the end of this nitrogen filling to the start of the next nitrogen filling, and combines the triggering factors when the next nitrogen filling starts to determine whether this pressure drop process is a complete pressure drop process. A complete pressure drop process refers to the pressure inside the battery box changing from P d Down to P c When the gas concentration or humidity inside the battery box does not meet the standard and the battery box is filled with nitrogen, the gas pressure inside the battery box is not reduced to P before nitrogen filling. c Therefore, the voltage drop process inside the battery box cannot be called a complete voltage drop process. If so, compare t1 and t2 with the preset voltage drop time to determine whether there is a problem with the air tightness of the battery box; if there is no problem, continue to perform the next nitrogen filling operation on the battery box.

[0113] In the fire extinguishing control logic S200, when the temperature T1 or T2 inside the two battery boxes is higher than the preset battery box internal temperature T m , or when the smoke sensor detects smoke inside the battery box, the main controller 400 issues a fire alarm and controls the fire extinguishing solenoid valve 320 to open, using the high-pressure air in the equipment auxiliary gas cylinder 210 to spray the cooling fire extinguishing agent 313 into the battery box 100. At the same time, the pressure sensors inside the two battery boxes monitor the air pressure P inside the battery box in real time. 2,1 and P 2,2 , if P 2,1 or P 2,2 Higher than the preset exhaust solenoid valve opening pressure threshold P n , the main controller 400 controls the exhaust solenoid valve 170 of the corresponding battery box to open and relieve the pressure on 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 temperature inside the battery box drops and the smoke dissipates, the main controller 400 controls the fire extinguishing solenoid valve 320 and the exhaust solenoid valve 170 to close, and at the same time, the temperature and smoke sensors in the battery box continue to monitor the inside of the battery box to prevent secondary re-ignition.

[0114] surface Symbols and corresponding instructions

[0115] symbol illustrate <![CDATA[P1]]> Gas pressure in gas cylinder (unit: kpa) <![CDATA[P 2,1 ]]> Gas pressure inside the first battery box (unit: kpa) <![CDATA[P 2,2 ]]> Gas pressure inside the second battery box (unit: kpa) <![CDATA[P a ]]> The preset gas pressure threshold of the gas storage tank when starting gas production (unit: kpa) <![CDATA[P b ]]> The preset gas pressure threshold of the gas cylinder when stopping gas production (unit: kpa) <![CDATA[P c ]]> The preset gas pressure threshold inside the battery box when starting to replenish inert gas (unit: kPa) <![CDATA[P d ]]> The preset gas pressure threshold inside the battery box when the inert gas is stopped (unit: kPa) <![CDATA[P m ]]> Pressure threshold for automatic opening of explosion-proof valve (unit: kpa) <![CDATA[P n ]]> <![CDATA[Preset exhaust solenoid valve opening pressure threshold (unit: kpa) and P d <P n <P m > <![CDATA[T1]]> The internal temperature of the first battery box (unit: °C) <![CDATA[T2]]> The internal temperature of the second battery box (unit: ℃) <![CDATA[T m ]]> Preset battery box internal temperature threshold (unit: °C) C Oxygen concentration at the battery box exhaust port <![CDATA[C m ]]> Preset oxygen concentration inside the battery box H Gas humidity at battery box exhaust port <![CDATA[H m ]]> Preset battery box internal gas humidity <![CDATA[t1]]> <![CDATA[After supplementing the inert gas, the internal gas pressure of the first battery box drops from P d to P c The time taken (unit: min)]]> <![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 inert gas once (unit: min) N <![CDATA[The time (unit: min) taken for the internally preset gas pressure in the battery box to drop from P d to P c >

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

[0117] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A power battery fire prevention and control system, characterized in that: include: A battery box (100) having a power battery and a detector assembly (110) built therein, the detector assembly (110) comprising a gas pressure sensor, a temperature sensor and a smoke sensor for monitoring the gas pressure value, the temperature value and the smoke value inside the battery box (100); an air inlet (120), an exhaust port (130) and an explosion-proof valve (140) are provided on the battery box (100); an exhaust duct is provided on the exhaust port (130) of the battery box (100); an oxygen concentration humidity sensor (150), a second one-way throttling assembly (160) and an exhaust solenoid valve (170) are provided on the exhaust duct in sequence; An inert gas prevention and control unit, comprising a gas storage bottle (260) for storing inert gas, a first one-way throttling assembly (270) and a gas storage bottle solenoid valve (280), wherein the gas storage bottle (260) is connected to the gas inlet (120) of the battery box (100) via the first one-way throttling assembly (270) and the gas storage bottle solenoid valve (280) in sequence; A fire extinguishing unit, comprising a fire extinguishing device (310), wherein the fire extinguishing device (310) has a cavity therein, wherein a piston (312) is movably disposed in the cavity, wherein the piston (312) divides the cavity into an air cavity and a medium cavity for storing a fire extinguishing agent (313), wherein an air inlet (311) on the fire extinguishing device (310) is in communication with the air cavity and is used for introducing compressed gas, wherein the air inlet (311) is provided with a fire extinguishing solenoid valve (320), wherein a fire extinguishing agent outlet (314) on the fire extinguishing device (310) is in communication with the medium cavity, and wherein the fire extinguishing agent outlet (314) is in communication with an air inlet (120) of the battery box (100); A main control unit comprises a main controller (400), wherein the main controller (400) is respectively electrically connected 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 cylinder solenoid valve (280), and the fire extinguishing solenoid valve (320).

2. The power battery fire prevention and control system according to claim 1, characterized in that: The main controller (400) is used to, when the gas pressure sensor detects that the gas pressure inside the battery box (100) is less than a preset gas pressure threshold (P) inside the battery box for starting to replenish inert gas, c ), or the oxygen concentration value detected by the oxygen concentration humidity sensor (150) is greater than or equal to a preset oxygen concentration (C m ), or the gas humidity value is greater than or equal to the preset battery box internal gas humidity (H m ), controlling the gas storage bottle solenoid valve (280) and the exhaust solenoid valve (170) to open; When the oxygen concentration value detected by the oxygen concentration humidity sensor (150) is less than or equal to the preset oxygen concentration (C m ), and the gas humidity value is less than or equal to the preset battery box internal gas humidity (H m ), the exhaust solenoid valve (170) is controlled to be closed and the gas storage bottle solenoid valve (280) is controlled to be opened, and when the gas pressure sensor detects that the gas pressure inside the battery box (100) is greater than a preset gas pressure threshold (P) inside the battery box for stopping replenishing inert gas d ), controlling the gas storage bottle solenoid valve (280) to close; And / or, the main controller (400) is used for, when the temperature sensor detects that the temperature inside the battery box (100) is higher than a preset battery box internal temperature threshold (T m ), or when the smoke sensor detects that the smoke value inside the battery box (100) is higher than a preset smoke concentration, the fire extinguishing solenoid valve (320) is controlled to open; when the temperature sensor detects that the temperature inside the battery box (100) is not higher than a preset battery box internal temperature threshold (T m ), or when the smoke sensor detects that the smoke value inside the battery box (100) does not reach a preset smoke concentration, controlling the fire extinguishing solenoid valve (320) to close; And / or, the main controller (400) is used to record the time required for replenishing the inert gas detected by the gas pressure sensor, and when the recorded time is less than a preset pressure drop time, send a prompt signal to an external prompt device; And / or, the main controller (400) is used for, when the gas pressure sensor detects that the gas pressure inside the battery box (100) is higher than a preset pressure threshold (P n ), controlling the exhaust solenoid valve (170) to open; when the gas pressure sensor detects that the gas pressure inside the battery box (100) is less than a preset exhaust solenoid valve opening pressure threshold (P n ), the exhaust solenoid valve (170) is controlled to close.

3. The power battery fire prevention and control system according to claim 1, characterized in that: The inert gas prevention and control unit further comprises a gas making device (240) and a third one-way throttling assembly (250); the gas making device (240) is provided with an air inlet, a first air outlet and a second air outlet; the air inlet of the gas making device (240) is used for introducing compressed air; the first air outlet of the gas making device (240) is communicated with the air inlet of the gas storage bottle (260); and the second air outlet of the gas making device (240) is used for discharging residual gas.

4. The power battery fire prevention and control system according to claim 3, characterized in that: The inert gas prevention and control unit further comprises an equipment auxiliary gas cylinder (210) and an air intake solenoid valve (220); the equipment auxiliary gas cylinder (210) is used to store compressed air; the equipment auxiliary gas cylinder (210) is connected to an air intake port of the gas production device (240) via the air intake solenoid valve (220).

5. The power battery fire prevention and control system according to claim 4, characterized in that: A filter cup (230) is provided between the air intake solenoid valve (220) and the gas production device (240) and is used to filter the gas in the equipment auxiliary gas cylinder (210); And / or, the inert gas prevention and control unit further comprises an air compressor, a condenser and a dryer, the air compressor being connected to the equipment auxiliary gas cylinder (210) via the condenser and the dryer in sequence; And / or, the gas making device (240) is an air membrane separation nitrogen making machine.

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

7. The power battery fire prevention and control system according to claim 4, characterized in that: The fire 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 equipment auxiliary gas cylinder (210); And / or, a fire extinguishing one-way 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).

8. The power battery fire prevention and control system according to claim 1, characterized in that: The number of the battery boxes (100) is plural.

9. A power battery fire prevention and control method, characterized in that: Using the power battery fire prevention and control system according to claim 6, the method comprises: Respectively receiving the detected 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 gas of the battery box (100); In the fire extinguishing control logic, when the gas temperature data inside the battery box (100) is higher than a preset battery box internal temperature threshold (T m ), or when the smoke data is higher than a preset smoke concentration, power is supplied to the fire extinguishing solenoid valve (320); when the gas pressure data inside the battery box (100) is higher than a preset pressure threshold (P n ), the exhaust solenoid valve (170) is powered, and when the gas temperature data inside the battery box (100) is lower than a preset battery box internal temperature threshold value (T m ) and when the smoke data is lower than a preset smoke concentration, the fire extinguishing solenoid valve (320) and the exhaust solenoid valve (170) are powered off; In the inert gas control logic, when the gas pressure data inside the battery box (100) is less than a preset gas pressure threshold (P c ), or the oxygen concentration data in the exhaust gas of the battery box (100) is greater than or equal to a preset oxygen concentration (C m ), or the gas humidity data is greater than or equal to the preset battery box internal gas humidity (H m ), the gas cylinder solenoid valve (280) and the exhaust solenoid valve (170) are powered, and when the oxygen concentration data in the exhaust gas of the battery box (100) is less than or equal to the preset oxygen concentration (C m ), and the gas humidity data is less than or equal to the preset battery box internal gas humidity (H m ), the exhaust solenoid valve (170) is powered off, and when the gas pressure data inside the battery box (100) is greater than a preset gas pressure threshold (P d ), the gas cylinder solenoid valve (280) is powered off, the time required for the battery box (100) to be replenished with inert gas is recorded, and when the required time is less than a preset pressure drop time, a prompt signal is sent to an external prompt device; In the gas production control logic, when the gas pressure data of the gas storage cylinder (260) is less than a preset gas storage cylinder gas pressure threshold value (P a ), the air inlet solenoid valve (220) is powered, and when the gas pressure data of the gas storage bottle (260) is greater than a preset gas storage bottle gas pressure threshold value (P b ), the air intake solenoid valve (220) is de-energized.

10. The power battery fire prevention and control method according to claim 9, characterized in that: The fire extinguishing control logic, the inert gas control logic and the gas production control logic are three independent logic modes that do not affect each other.

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