Lithium ion battery cabin oxygen concentration control system

Abstract

The invention discloses a lithium ion battery cabin oxygen concentration control system, and relates to the technical field of fire fighting. The oxygen concentration control system comprises an oxygen concentration sensor, a nitrogen making machine, a nitrogen station, an air compressor, a compressed air storage tank, a high-temperature-resistant and high-pressure-resistant seamless steel pipe, a one-way valve, a PLC (Programmable Logic Controller), a gas replacement indicator lamp, a lithium ion battery cabin and a battery cabin air inlet and exhaust flow control regulating valve. The controller is respectively connected with the oxygen concentration sensor, the nitrogen station, the compressed air storage tank, the lithium ion battery cabin air inlet and exhaust flow control regulating valve and the gas replacement indicator lamp. The nitrogen station is provided with a purging pressure measuring valve and a nitrogen cylinder head valve, and the high-temperature-resistant and high-pressure-resistant seamless steel pipe is connected with the nitrogen making machine, the nitrogen station, the lithium ion battery cabin, the air compressor and the compressed air storage tank. The lithium ion battery cabin is filled with high-purity nitrogen through the oxygen concentration control system, so that gas in the cabin is replaced, and controllable adjustment of an inerting environment in the cabin is realized. In addition, after the battery is subjected to thermal runaway, high-purity nitrogen is filled into the lithium ion battery cabin, thermal runaway flue gas in the cabin is quickly purged and replaced, and then an electric ball valve is linked to start air replacement, so that the air environment of the experiment cabin is kept.

Description

Technical Field

[0001] The invention provides a lithium-ion battery compartment oxygen concentration control system, belonging to the technical field of fire protection. Technical Background

[0002] Oxygen is one of the necessary elements for fire, and an oxygen-filled environment will aggravate the occurrence and spread of fire. If the oxygen concentration in the lithium-ion battery compartment is too high, once the battery thermal runaway occurs, the fire will easily spread, leading to a fire accident. Therefore, controlling the oxygen concentration in the lithium-ion battery compartment can reduce the probability of fire and effectively control and extinguish the fire. When the lithium-ion battery compartment has thermal runaway, a large amount of hot smoke will be generated. Blowing out the hot smoke in time can prevent the spread of fire and reduce the accumulation of harmful gases, thereby protecting the safety of personnel and reducing the hazards of fire. Summary of the invention

[0003] The inert environment control of the lithium-ion battery compartment is crucial to the safe operation of the lithium-ion battery compartment. The present invention provides an oxygen concentration control system for the lithium-ion battery compartment. The present invention adopts the following technical solutions:

[0004] A lithium-ion battery compartment oxygen concentration control system includes an oxygen concentration sensor, a nitrogen generator, a nitrogen station, an air compressor, a compressed air storage tank, a high temperature and high pressure resistant seamless steel pipe, a one-way valve, a PLC controller, a gas replacement indicator light, a lithium-ion battery compartment, and a battery compartment air intake and exhaust flow control regulating valve. The controller is respectively connected to the oxygen concentration sensor, the nitrogen station, the compressed air storage tank, the lithium-ion battery compartment air intake and exhaust flow control regulating valve, and the gas replacement indicator light. The high temperature and high pressure resistant seamless steel pipe connects the nitrogen generator, the nitrogen station, the lithium-ion battery compartment, the air compressor, and the compressed air storage tank.

[0005] Furthermore, the nitrogen station is equipped with a purge pressure measuring valve and a nitrogen cylinder head valve.

[0006] Furthermore, the one-way valve is arranged on the high-temperature and pressure-resistant seamless steel pipe for nitrogen transportation to prevent backflow so as to ensure the purity of high-purity nitrogen in the nitrogen station.

[0007] A lithium-ion battery compartment oxygen concentration control system, the specific working process includes: the first step, the oxygen concentration sensor is used to monitor the oxygen concentration in the battery compartment in real time, and the oxygen concentration value is converted into an electrical signal and transmitted to the controller; the second step, the controller calculates the error value between the actual oxygen concentration and the target oxygen concentration. If the measured value is lower than the target oxygen control concentration, the controller will close the nitrogen station valve and stop nitrogen filling. If the measured value is higher than the oxygen control concentration, the controller will continue to open the nitrogen station valve. Once the actual concentration is close to the target concentration and the error value is small enough, the controller will maintain this state and achieve stable control.

[0008] Furthermore, after the battery has thermal runaway, the controller controls the regulating valve by adjusting the intake and exhaust flow rates, and uses a faster nitrogen flow rate to purge the smoke in the cabin, thereby quickly purging and replacing the thermal runaway smoke that may exist in the cabin.

[0009] Furthermore, the control system can link the electric ball valve to start the compressed air storage tank to replace air, thereby restoring the oxygen concentration in the lithium-ion battery compartment to the normal air oxygen concentration under standard atmospheric pressure.

[0010] Furthermore, when the reserves of the nitrogen station are insufficient to construct a low-oxygen environment in the battery cabin, the nitrogen generator is used to prepare high-purity nitrogen, and the controller sets the nitrogen station to a nitrogen replenishment mode to supply the nitrogen station with high-purity nitrogen.

[0011] Furthermore, when the oxygen concentration control system replaces the gas in the battery compartment, the controller turns on the gas replacement indicator light to prevent people from entering by mistake.

[0012] Beneficial effects of the present invention: The oxygen concentration control system of the present invention can realize the inerting environment, hot flue gas purging and air replacement in the cabin, and maintain the safety and stability of the lithium-ion battery cabin. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A schematic diagram of the structure of an oxygen concentration control system for a lithium-ion battery compartment.

[0014] Explanation of the accompanying symbols: 1. Oxygen concentration sensor; 2. Nitrogen generator; 3. Nitrogen station; 4. Air compressor; 5. Compressed air storage tank; 6. High temperature and high pressure resistant seamless steel; 7. Check valve; 8. Lithium-ion battery compartment; 9. Battery compartment air intake flow control regulating valve; 10. Exhaust flow control regulating valve. DETAILED DESCRIPTION

[0015] The present invention discloses a lithium-ion battery compartment oxygen concentration control system, and an implementation mode of the present invention is described in detail below in conjunction with the accompanying drawings.

[0016] like Figure 1 The invention discloses a lithium-ion battery cabin oxygen concentration control system, comprising an oxygen concentration sensor 1, a nitrogen generator 2, a nitrogen station 3, an air compressor 4, a compressed air storage tank 5, a high temperature and high pressure resistant seamless steel pipe 6, a one-way valve 7, a PLC controller, a gas replacement indicator light, a lithium-ion battery cabin 8, and a battery cabin air intake 9 and exhaust 10 flow control regulating valves.

[0017] A lithium-ion battery cabin oxygen concentration control system can realize an inerting environment, hot flue gas purging and air replacement in the cabin, and maintain the safety and stability of the lithium-ion battery cabin. The specific workflow for realizing an inerting environment in the cabin includes: the first step, the oxygen concentration sensor 1 monitors the oxygen concentration in the battery cabin 8 in real time, converts the oxygen concentration value into an electrical signal and transmits it to the controller; the second step, the controller calculates the error value between the actual oxygen concentration and the target oxygen concentration. If the measured value is lower than the target oxygen control concentration, the controller will close the valve of the nitrogen station 3 and stop nitrogen filling. If the measured value is higher than the oxygen control concentration, the controller will continue to open the valve of the nitrogen station 3. After the controller executes the control operation, it re-measures the oxygen concentration in the environment and compares it with the target value again. By continuously performing measurement, comparison and adjustment operations, the error is gradually reduced so that the actual concentration is close to the target concentration. When the error value is small enough, the controller will maintain this state and achieve stable control.

[0018] Furthermore, the specific working process of hot flue gas purging includes: after the battery has thermal runaway, the controller controls the regulating valves by adjusting the flow of intake air 9 and exhaust air 10, and uses a faster nitrogen flow rate to purge the flue gas in the battery compartment 8, thereby quickly purging and replacing the thermal runaway flue gas that may exist in the compartment.

[0019] Furthermore, the specific working process of air replacement includes: the control system can link the electric ball valve to start the compressed air storage tank 5 to replace the air, and restore the oxygen concentration in the lithium-ion battery compartment 8 to the normal air oxygen concentration under standard atmospheric pressure.

[0020] Furthermore, when the reserves of the nitrogen station 3 are insufficient to construct a low-oxygen environment in the battery compartment 8, the nitrogen generator 2 is used to prepare high-purity nitrogen, and the controller sets the nitrogen station 3 to a nitrogen replenishment mode to supply the nitrogen station with high-purity nitrogen.

[0021] Furthermore, in terms of the design of the nitrogen station 3, it is assumed that the injected nitrogen can be fully mixed with the gas in the battery compartment 8 immediately, and that the gas pressure in the battery compartment 8 remains unchanged. Assuming that the initial oxygen concentration is R, the volume of the lithium-ion battery compartment 8 is Π, and after the nitrogen is injected dV, the oxygen removed is The oxygen concentration changes to

[0022]

[0023] Right now

[0024]

[0025] Integrate both sides

[0026]

[0027] Available

[0028]

[0029] Right now

[0030]

[0031] Input the initial oxygen concentration R0, the volume of the lithium-ion battery compartment 8 Π, and draw a curve of oxygen concentration and injected nitrogen volume R1~V according to the above formula. According to the target oxygen concentration, the volume of nitrogen required to be injected can be estimated. The storage capacity of the nitrogen station 3 is designed to meet the number of times the low oxygen environment of the battery compartment 8 is constructed, as well as the nitrogen storage pressure, and the volume of the nitrogen station 3 can be calculated according to the following formula:

[0032]

[0033] Wherein, V is the volume of nitrogen station 3 (L); n is the amount of substance (mol); R is the gas constant, which is 8.31 kPa L / (molk); T is the absolute temperature, which is 293.15 k; and P is the container pressure (kPa).

[0034] The above embodiments are not intended to limit the present invention. It should be noted that, for those skilled in the art, several modifications and improvements may be made without departing from the concept of the present invention, and these modifications and improvements all belong to the protection scope of the present invention. Therefore, the present invention and the protection scope shall be subject to the attached claims.

Claims

1. A lithium-ion battery compartment oxygen concentration control system, characterized in that: The invention comprises an oxygen concentration sensor (1), a nitrogen generator (2), a nitrogen station (3), an air compressor (4), a compressed air storage tank (5), a high temperature and high pressure resistant seamless steel pipe (6), a one-way valve (7), a PLC controller, a gas replacement indicator light, a lithium ion battery compartment (8), and a battery compartment air intake (9) and exhaust (10) flow control regulating valve. The controller is respectively connected to the oxygen concentration sensor (1), the nitrogen station (3), the compressed air storage tank, (5) the lithium ion battery compartment air intake (9) and exhaust (10) flow control regulating valve, and the gas replacement indicator light. The high temperature and high pressure resistant seamless steel pipe (6) is connected to the nitrogen generator (2), the nitrogen station (3), the lithium ion battery compartment (8), the air compressor (4) and the compressed air storage tank (5).

2. A lithium-ion battery compartment oxygen concentration control system according to claim 1, characterized in that: The lithium-ion battery compartment (8) is provided with an oxygen concentration sensor (1), an air intake (9) and an exhaust (10) flow control regulating valve, and nitrogen filling and exhaust of the gas in the compartment are carried out simultaneously through mixed replacement.

3. A lithium-ion battery compartment oxygen concentration control system according to claim 2, characterized in that: The nitrogen station (3) is equipped with a purge pressure measuring valve and a nitrogen bottle head valve, and the one-way valve (7) is arranged on the nitrogen transport high temperature and pressure resistant seamless steel pipe (6) to prevent backflow and ensure the purity of the high purity nitrogen in the nitrogen station.

4. A lithium-ion battery compartment oxygen concentration control system according to claim 3, characterized in that: High-purity nitrogen is filled into the lithium-ion battery compartment through the oxygen concentration control system to replace the gas in the compartment, so as to achieve controllable regulation of the inert environment in the compartment. In addition, after the battery has thermal runaway, high-purity nitrogen is filled into the lithium-ion battery compartment to quickly purge and replace the thermal runaway smoke in the compartment, and then the electric ball valve is linked to start air replacement to maintain the air environment in the experimental compartment.

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