Battery pack liquid nitrogen fire extinguishing system for engineering machinery

Abstract

The battery pack liquid nitrogen fire extinguishing system comprises a controller, a battery pack, a liquid nitrogen storage tank, an electric pressure pump, a walking motor and a battery management system which are arranged on an excavator frame, the controller is electrically connected with the battery management system, the battery management system is electrically connected with the battery pack, and the output end of the battery pack is connected with the walking motor. The battery pack comprises a battery pack shell, a plurality of battery packs are arranged on the inner side of the battery pack shell, the controller is electrically connected with a smoke sensor controller, an electric pressure pump and a fan, the electric pressure pump is connected with a liquid nitrogen storage tank, and the output end of the liquid nitrogen storage tank is connected with a spraying mechanism through a second electromagnetic valve. The device achieves the functions of accurately recognizing the battery state, being high in reliability, effectively extinguishing fire and extracting internal air to cooperate with a spraying mechanism to extinguish fire when a fire breaks out.

Description

Technical Field

[0001] The application of the present invention relates to the technical field of excavators, specifically a liquid nitrogen fire protection system for battery packs used in construction machinery. Background Technique

[0003] Since most new energy construction machinery uses lithium batteries as carriers to provide energy for the equipment, the safety issue of lithium batteries during operation is a very important problem. At present, most of the batteries of new energy construction machinery work without fire protection measures. Considering the operating environment of construction machinery, when the battery is impacted and undergoes a thermal reaction, the possibility of fire increases sharply. To sum up, there is an urgent need for a fire protection technical solution for battery packs used in construction machinery.

[0004] Therefore, designing a device that can accurately identify the battery status, has high reliability, and can effectively extinguish fires is exactly the problem to be solved by the inventor. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a liquid nitrogen fire protection system for battery packs used in construction machinery, which can achieve the functions of accurately identifying the battery status, high reliability, and effective fire extinguishing.

[0006] The technical solution adopted by the device of the present invention is: a liquid nitrogen fire protection system for battery packs used in construction machinery, including a controller, a battery pack, a liquid nitrogen storage tank, an electric pressure pump, a walking motor, and a battery management system arranged on the excavator frame. The controller is electrically connected to the battery management system, the battery management system is electrically connected to the battery pack, the output end of the battery pack is connected to the walking motor. The battery pack includes a battery pack housing, and several groups of battery packs are arranged inside the battery pack housing. The controller is electrically connected to a smoke sensor controller, the controller is electrically connected to an electric pressure pump, the controller is electrically connected to a fan. The electric pressure pump is connected to the liquid nitrogen storage tank, the output end of the liquid nitrogen storage tank is connected to a spraying mechanism through a second electromagnetic valve, the fan is connected to the battery pack housing through a first electromagnetic valve, the spraying mechanism is arranged inside the battery pack housing, and smoke sensors are arranged on the battery packs. All the smoke sensors are connected to the smoke sensor controller.

[0007] Further, all the battery packs are arranged in parallel, and a first electric control switch and a second electric control switch are respectively arranged at the wire ends of the battery packs.

[0008] Further, all the first electric control switches are connected in parallel and electrically connected to the battery management system, and all the second electric control switches are connected in parallel and electrically connected to the walking motor.

[0009] Further, the first electromagnetic valve and the second electromagnetic valve are both electrically connected to the controller.

[0010] Further, the spraying mechanism includes a connecting joint, a shunt pipe, and a high-pressure nozzle. The input end of the shunt pipe is connected with the connecting joint. The shunt pipe is provided with evenly distributed connecting holes, and the inner sides of the connecting holes are connected with the high-pressure nozzles.

[0011] Further, one end of the battery pack housing is provided with an air vent, and a solenoid valve is arranged at the air vent.

[0012] Further, the peripheral side walls and the top cover of the battery pack housing are detachably arranged.

[0013] The beneficial effects of the device of the present invention are as follows: 1. The present invention uses a controller to take overall control of the operation of all electronic components, receives in real time the electronic signals transmitted back by the smoke sensor, and at the same time, the built-in alarm system in the battery management system serves as an auxiliary to judge the fire situation of the battery packs in the battery pack, and controls the electric pressure pump to pressurize, so that liquid nitrogen is sprayed from the spraying mechanism during a fire. When a fire occurs and generates smoke, the controller, according to the preset system, controls the first electric control switch and the second electric control switch to cut off the connection circuit between the burning battery pack and the parallel battery packs, preventing the fire from spreading rapidly along the wires to extend the time for other battery packs to be ignited, realizing the functions of accurately identifying the battery state, high reliability, and effective fire extinguishing.

[0014] 2. The present invention uses a fan as the air source. The fan can rotate forward and backward. When rotating forward, it extracts negative pressure from the battery pack, and when rotating backward, it blows air into the battery pack for cooling, realizing the function of extracting internal air to cooperate with the spraying mechanism for fire extinguishing during a fire. Description of the Drawings

[0015] Figure 1 It is the system structure block diagram of the present invention.

[0016] Description of the reference numerals: 1 - controller; 2 - smoke sensor controller; 3 - battery management system; 4 - electric pressure pump; 5 - liquid nitrogen storage tank; 6 - fan; 7 - first solenoid valve; 8 - second solenoid valve; 9 - spraying mechanism; 10 - first electric control switch; 11 - smoke sensor; 12 - battery pack; 13 - battery pack housing; 14 - second electric control switch; 15 - traveling motor. Detailed Embodiments

[0017] The following will further elaborate on the device of the present invention in combination with specific embodiments. These embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the device of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the application.

[0018] See Figure 1It is a system structure block diagram of the present invention, a battery pack liquid nitrogen fire fighting system for engineering machinery, including a controller 1, a battery pack, a liquid nitrogen storage tank 5, an electric booster pump 4, a travel motor 15, and a battery management system 3 arranged on an excavator frame. The controller 1 is electrically connected to the battery management system 3. The battery management system 3 is a standing system for new energy vehicles and new energy engineering vehicles, and is used to manage battery power supply, charging and other operations. The battery management system 3 is electrically connected to the battery pack, and the battery pack includes a battery pack shell 13. A plurality of battery packs 12 are arranged on the inner side of the battery pack shell 13. The battery pack 12 is composed of a plurality of battery cells or battery blocks connected in series, and the battery pack is composed of a plurality of battery packs 12 connected in parallel. The series connection increases the voltage, and the parallel connection increases the capacity, and is used to supply power to the excavator.

[0019] The output end of the battery pack is connected to a travel motor 15 for driving the excavator.

[0020] The controller 1 is electrically connected to the smoke sensor controller 2, and the battery pack 12 is provided with a smoke sensor 11. All the smoke sensors 11 are connected to the smoke sensor controller 2, and all the circuits of the smoke sensors 11 are aggregated to the smoke sensor controller 2 for unified real-time monitoring and control, and then the smoke sensor 11 further transmits the signal to the controller 1 for response.

[0021] The controller 1 is electrically connected to an electric booster pump 4, which is connected to a liquid nitrogen storage tank 5. The output end of the liquid nitrogen storage tank 5 is connected to a spray mechanism 9 through a second solenoid valve 8. The spray mechanism 9 includes a connecting joint, a shunt pipe, and a high-pressure nozzle. The input end of the shunt pipe is connected to a connecting joint. The shunt pipe is provided with evenly distributed connecting holes, and a high-pressure nozzle is connected to the inner side of the connecting holes. The spray mechanism 9 is arranged on the inner side of the battery pack shell 13. After the controller 1 receives the signal from the smoke sensor 11, it controls the booster pump to work and pressurize, so that the liquid nitrogen in the liquid nitrogen storage tank 5 enters the spray mechanism 9 and is sprayed from the high-pressure nozzle to extinguish the fire.

[0022] The controller 1 is electrically connected to a blower 6. The blower 6 is connected to the battery pack housing 13 through a first solenoid valve 7. Both the first solenoid valve 7 and the second solenoid valve 8 are electrically connected to the controller 1. The blower 6 uses an axial flow blower 6 as the main body. The advantage of the axial flow blower 6 is that it can switch the wind direction with equal air volume when switching between forward and reverse rotations. One end of the battery pack housing 13 is provided with an air outlet, and a solenoid valve is provided at the air outlet. Under normal conditions, the blower 6 blows air into the battery pack to cool the battery pack 12. When a fire breaks out inside the battery pack housing 13 and the smoke sensor 11 transmits a signal to the controller 1, the blower 6 rotates in reverse and changes to extract negative pressure outward. At the same time, the solenoid valve provided at the air outlet is closed. Under normal conditions, the air outlet is in an open state for air exchange inside the battery pack to prevent external oxygen from continuously entering the battery pack. During this process, liquid nitrogen is sprayed to quickly fill nitrogen in the battery pack. Because of combustion and the extraction of negative pressure, the oxygen component in the air rapidly decreases, which can effectively inhibit the spread of the fire.

[0023] All the battery packs 12 are connected in parallel. First electric control switches 10 and second electric control switches 14 are respectively provided at the wire ends of the battery packs 12. By controlling the first electric control switches 10 and the second electric control switches 14 through the controller 1, the circuit can be effectively cut off, and the faulty battery pack 12 can be excluded from the power supply system. All the first electric control switches 10 are connected in parallel and electrically connected to the battery management system 3. All the second electric control switches 14 are connected in parallel and electrically connected to the traveling motor 15. For the convenience of installation, disassembly, and maintenance of the battery packs 12, the peripheral side walls and the top cover of the battery pack housing 13 are detachably provided.

[0024] The smoke sensor 11 and the battery management system 3 collect data around the battery pack. The controller 1 is responsible for collecting and analyzing the data collected by the sensors and the battery management system 3, and comparing it with the target value. The controller 1 is connected to an electric pressure pump 4 to make it pressurize. The electric pressure pump 4 is controlled as follows: Based on the comparison of the collected sensing data, the smoke level, open fire, and temperature parameters are calculated. At the same time, they are compared with the preset parameters in the controller 1. When the actual parameters reach the starting value of the electric pressure pump 4 preset in the controller 1, the controller 1 outputs a high-voltage signal to start the operation of the electric pressure pump 4. When the actual parameters detected by the sensor drop to the stopping value of the electric pressure pump 4 preset in the controller 1, the controller 1 outputs a low-voltage signal to stop the operation of the electric pressure pump 4. When the smoke sensor 11 and the battery management system 3 detect an abnormal battery pack state, the controller 1 outputs a starting signal to the electric pressure pump 4, and the electric pressure pump 4 starts to increase the pressure in the liquid nitrogen storage tank. At the same time, the controller 1 outputs an opening signal to the second solenoid valve 8 on the gas outlet of the liquid nitrogen storage tank to open the second solenoid valve 8. Under the pressure provided by the electric pressure pump 4, the liquid nitrogen is sprayed to the battery pack 12 and the ignition point through the spraying mechanism 9, quickly blocking the thermal reaction of the battery pack and diluting oxygen. Until the battery management system 3 and the smoke sensor 11 detect that the battery pack reaches a safe state, the controller 1 controls the electric pressure pump 4 to stop working, and at the same time issues a closing signal to the second solenoid valve 8 at the gas outlet of the liquid nitrogen storage tank to close the solenoid valve and stop the liquid nitrogen spraying, so as to achieve the purpose of fire extinguishing and fire protection.

[0025] In the present invention, the controller 1 takes overall control of the operation of all electronic components, receives the electronic signals transmitted back by the smoke sensor 11 in real time, and at the same time, the built-in alarm system in the battery management system 3 serves as an auxiliary to judge the fire situation of the battery pack 12 in the battery pack, and controls the electric pressure pump 4 to pressurize. When a fire breaks out, the liquid nitrogen is sprayed from the spraying mechanism 9. When a fire breaks out and generates smoke, the controller 1, according to the preset system, controls the first electric control switch 10 and the second electric control switch 14 to cut off the connection circuit between the burning battery pack 12 and the parallel battery packs 12, preventing the fire from spreading rapidly along the wire to extend the time for other battery packs 12 to be ignited, realizing the functions of accurately identifying the battery state, high reliability, and effective fire extinguishing. Using the fan 6 as the air source, the fan 6 can rotate forward and backward. When rotating forward, it extracts negative pressure from the battery pack, and when rotating backward, it blows air into the battery pack for cooling as the fan 6, realizing the function of extracting internal air to cooperate with the spraying mechanism 9 to extinguish the fire when a fire breaks out.

Claims

1. A battery pack liquid nitrogen fire fighting system for construction machinery, comprising a controller (1) arranged on an excavator frame, a battery pack, a liquid nitrogen storage tank (5), an electric booster pump (4), a travel motor (15), and a battery management system (3), wherein the controller (1) is electrically connected to the battery management system (3), the battery management system (3) is electrically connected to the battery pack, and the output end of the battery pack is connected to the travel motor (15), characterized in that: The battery pack comprises a battery pack shell (13), a plurality of battery packs (12) are arranged inside the battery pack shell (13), the controller (1) is electrically connected to a smoke sensor controller (2), the controller (1) is electrically connected to an electric booster pump (4), the controller (1) is electrically connected to a fan (6), the electric booster pump (4) is connected to a liquid nitrogen storage tank (5), the output end of the liquid nitrogen storage tank (5) is connected to a spray mechanism (9) via a second solenoid valve (8), the fan (6) is connected to the battery pack shell (13) via a first solenoid valve (7), the spray mechanism (9) is arranged inside the battery pack shell (13), a smoke sensor (11) is arranged on the battery pack (12), and all the smoke sensors (11) are connected to the smoke sensor controller (2).

2. A battery pack liquid nitrogen fire fighting system for engineering machinery according to claim 1, characterized in that: All the battery packs (12) are arranged in parallel, and the wires at both ends of the battery packs (12) are respectively provided with a first electrically controlled switch (10) and a second electrically controlled switch (14).

3. A battery pack liquid nitrogen fire fighting system for engineering machinery according to claim 2, characterized in that: All of the first electrically controlled switches (10) are connected in parallel and electrically connected to a battery management system (3), and all of the second electrically controlled switches (14) are connected in parallel and electrically connected to a travel motor (15).

4. The battery pack liquid nitrogen fire fighting system for engineering machinery according to claim 1, characterized in that: The first solenoid valve (7) and the second solenoid valve (8) are both electrically connected to the controller (1).

5. The battery pack liquid nitrogen fire fighting system for engineering machinery according to claim 1, characterized in that: The spray mechanism (9) comprises a connecting joint, a shunt pipe, and a high-pressure nozzle. The input end of the shunt pipe is connected to the connecting joint. The shunt pipe is provided with evenly distributed connecting holes. The inner side of the connecting hole is connected to the high-pressure nozzle.

6. The battery pack liquid nitrogen fire fighting system for engineering machinery according to claim 1, characterized in that: One end of the battery pack housing (13) is provided with an air outlet, and a solenoid valve is provided at the air outlet.

7. The battery pack liquid nitrogen fire fighting system for engineering machinery according to claim 1, characterized in that: The surrounding side walls and the top cover of the battery pack housing (13) are detachable.

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