CN111272341A - Battery box electrolyte leakage detection device and electrolyte leakage detection method - Google Patents

Abstract

The invention relates to a battery box electrolyte leakage detection device and an electrolyte leakage detection method.A device comprises an air supply system and an electrolyte leakage detection system which are respectively connected with a tested piece; the gas supply system comprises a gas source, a first valve and a pressure sensor which are sequentially connected in series; the electrolyte leakage detection system is connected between the pressure sensor and the tested piece and comprises a third valve and a PID sensor which are sequentially connected, and according to different requirements, the electrolyte leakage detection system can be further provided with a humidity detection system or a test gas tank and a fifth valve are additionally arranged in the electrolyte leakage detection system. The PID sensor detects the gas humidity before testing, and can be directly cleaned by utilizing clean air generated by an air source, so that the service life of the PID sensor is prolonged; the PID sensor tests the gas temporarily stored in the testing gas tank, the detection accuracy is higher for each batch of gas, and the specific concentration of the electrolyte can be calculated.

Description

Battery box electrolyte leakage detection device and electrolyte leakage detection method

technical field

The invention relates to the technical field of electrolyte leakage detection, in particular to a battery box electrolyte leakage detection device and an electrolyte leakage detection method.

Background technique

With the development of polymer battery technology and the continuous improvement of customer requirements, liquid leakage has become a difficult point in the quality control of polymer batteries, and it is also the carrier of the core competitiveness of product quality. In the case of , the internal electrolyte will flow out, and the external air will enter the battery, which will cause the battery to swell. Therefore, how to prevent electrolyte leakage has become an important aspect of competition among battery manufacturers.

In order to prevent the problem of electrolyte leakage in polymer batteries, on the one hand, during production, the packaging method is improved to improve the sealing performance of the packaging, and on the other hand, the method for detecting liquid leakage is improved. At present, the methods for detecting liquid leakage include appearance inspection, vacuum inspection and leakage material inspection. Appearance inspection depends on the detection ability of the inspector. Vacuum inspection is to use the characteristics of the leaking battery to evacuate the battery, and form a larger size outside the leaking battery. If the differential pressure is high, the electrolyte may be flowed out of the battery along with the internal product flow, and then the appearance inspection will be carried out. Both appearance inspection and vacuum inspection have the problem of low detection rate.

The leakage detection adopts an electrolyte leakage detector, such as the lithium battery negative pressure transformation automatic detection system disclosed in the patent number CN108091817A, including several independent pipes independently connected to the battery main pipe, and the front end of the independent pipe is fixed with negative pressure The suction nozzle body is formed into a suction nozzle body, and the negative pressure suction nozzle body is pressed and sucked on the upper surface of the battery injection port that needs to be transformed into a lithium battery body; a pressure sensor and a flowmeter are arranged in the battery main conduit, and the pressure sensor and flowmeter pass through. The signal line is connected with the PLC control system.

The above-mentioned electrolyte leakage detector mainly adopts the negative pressure pump suction detection method, which has the following shortcomings: (1) The tested piece has an explosion-proof film at the gas injection port, and the pump suction gas pipe cannot extend into the box, which is inconvenient to use. There are deviations in the test results; (2) The negative pressure pump suction detection method cannot accurately set the negative pressure value, which is easy to cause excessive negative pressure, which will cause damage to the airtight structure of the tested part; (3) The suction pump is long-term (4) The pump suction detector does not have the self-cleaning function of the PID sensor. After long-term use, the PID sensor is prone to poisoning and the test results are biased.

SUMMARY OF THE INVENTION

The purpose of the present invention is to design a battery box electrolyte leakage detection device and an electrolyte leakage detection method according to the defects of the electrolyte leakage detector in the prior art.

In order to achieve the purpose, the technical scheme provided by the invention is:

The invention relates to a battery box electrolyte leakage detection device, which includes an air supply system and an electrolyte leakage detection system respectively connected to the measured component; the air supply system includes an air source, a first valve and an The pressure sensor used to measure the air pressure in the tested part; the electrolyte leakage detection system is respectively connected with the pressure sensor and the tested part, and the electrolyte leakage detection system includes a third valve connected in turn and a third valve for detecting the tested part electrolyte. PID sensor for leak conditions.

Preferably, the gas supply system further includes a buffer gas tank and a second valve, and the buffer gas tank and the second valve are sequentially connected between the first valve and the pressure sensor. By switching the first valve and the second valve alternately, the gas generated by the gas source is first buffered in the buffer gas tank, and then the air in the buffer gas tank is filled into the test piece. The gas input in the test piece is more stable, and there are Conducive to protect the DUT from damage.

Preferably, the electrolyte leakage detection system is further equipped with a humidity detection system, the humidity detection system is respectively connected with the pressure sensor and the measured object, and the humidity detection system includes a fourth valve connected in series and used for detecting the gas in the measured object. A humidity sensor for humidity; the outlet ends of the electrolyte leakage detection system and the humidity detection system are connected to each other and are connected with a muffler. Before the electrolyte leakage detection system detects the gas, first use the humidity detection system to detect the humidity of the gas, and then perform the electrolyte leakage detection after the humidity detection meets the requirements, so as to prevent the water vapor in the gas from causing damage to the PID sensor and further increase the service life of the PID sensor. ; The function of the muffler is to prevent excessive noise when the detection gas is discharged.

Preferably, the electrolyte leakage detection system further comprises a test gas tank and a fifth valve, the test gas tank and the fifth valve are sequentially connected in series with the PID sensor, and a muffler is connected to the end of the electrolyte leakage detection system. The third valve and the fifth valve are switched on and off alternately, and the PID sensor tests the gas temporarily stored in the test gas tank. For each batch of gas, the PID sensor has sufficient time to detect, and the detection accuracy is higher, and it can also be calculated by calculation. The concentration of the electrolyte can be calculated.

Preferably, between the air source and the first valve, an automatic drain for discharging the air source to generate water vapor in the gas is also connected; the air source and the first valve are also connected with an intake pressure reducing valve and a precision pressure regulating valve. The compressed gas generated by the air source will carry water vapor when it comes out. Especially in the air compressor that has not been drained for a long time, the water vapor content is very large. The function of the automatic drain is to discharge the water vapor in the compressed air. The air inlet pressure reducing valve is used to reduce the air pressure when the gas enters the air supply system, and the precision pressure regulating valve is used to precisely control the air pressure in the air supply system. The two work together to prevent the air pressure entering the air supply system from being too high.

The present invention also relates to an electrolyte leakage detection method, which is realized based on a battery box electrolyte leakage detection device, wherein the battery box electrolyte leakage detection device includes a gas supply system and an electrolyte leakage detection device respectively connected to the tested piece. system; the air supply system includes an air source, a first valve and a pressure sensor connected in series in sequence; the electrolyte leakage detection system is connected between the pressure sensor and the measured component, and the electrolyte leakage detection system includes sequentially connected The third valve and the PID sensor; the detection method includes the following steps:

S1: Close the third valve, open the first valve, and the air source will inflate the DUT until the pressure sensor detects that the air pressure in the DUT reaches the set value, close the first valve and leave it for a period of time to let the DUT The internal gas is well mixed with the injected air;

S2: Open the third valve, the mixed gas flows out from the tested part, and is discharged after passing through the PID sensor. The PID sensor detects whether there is electrolyte leakage;

S3: After the detection is completed, open the first valve and the third valve, and the air source directly blows air to the PID sensor to clean the PID sensor.

Preferably, the air supply system further includes an automatic drain, an intake pressure reducing valve, a precision pressure regulating valve, a buffer gas tank and a second valve, and the automatic drain, the intake pressure reducing valve and the precision pressure regulating valve are connected in sequence Between the gas source and the first valve, the buffer gas tank and the second valve are sequentially connected between the first valve and the pressure sensor, and the specific steps of step S1 include:

S1.1: Close the third valve and the second valve, adjust the intake pressure reducing valve and the precision pressure regulating valve, the gas source first inflates the buffer gas tank, and the gas passes through the automatic drain to remove water vapor;

S1.2: Close the first valve and open the second valve, the buffer gas tank is inflated to the DUT, and the pressure of the gas in the DUT is detected by the pressure sensor;

S1.3: Determine whether the air pressure in the tested piece detected by the pressure sensor reaches the set value. If it does not reach the set value, repeat steps S1.1 and S1.2 to alternately turn on and off the first valve and the second valve. Make the air source inflate the test piece through the buffer gas tank to reach the preset air pressure. If the set value is reached, close the first valve and the second valve and let it stand for a period of time, so that the gas inside the test piece is fully mixed with the injected air.

Preferably, the electrolyte leakage detection system is further equipped with a humidity detection system, the humidity detection system is respectively connected with the pressure sensor and the measured object, and the humidity detection system includes a fourth valve connected in series and used for detecting the gas in the measured object. A humidity sensor for humidity; the specific steps of step S2 include:

S2.1: Open the fourth valve, the mixed gas flows out from the tested part, passes through the fourth valve and the humidity sensor and then is discharged. The humidity sensor detects the humidity in the mixed gas. If the humidity is greater than the threshold value, the mixed gas is emptied and the detection is stopped. ; If the humidity is less than the threshold, enter S2.2;

S2.2: Close the fourth valve and open the third valve, the mixed gas flows out from the tested part, and then is discharged after passing through the PID sensor. The PID sensor detects whether there is electrolyte leakage.

Preferably, the electrolyte leakage detection system further includes a test gas tank and a fifth valve, and the test gas tank and the fifth valve are connected in series with the PID sensor in sequence, and the specific steps of step S2 include:

S2.1: The gas inside the test piece is fully mixed with the injected air, and the pressure sensor records the pressure value P ₁ ;

S2.2: Open the third valve and close the fifth valve, part of the gas inside the DUT flows into the test gas tank through the third valve, the pressure sensor detects the pressure value as P ₂ ⁿ , and the PID sensor detects the gas in the test gas tank. Carry out detection, the detection value is K ⁿ , and n is the current number of gas detection by the PID sensor;

S2.3: After the PID sensor detects the gas in the test gas tank for a period of time, close the third valve and open the fifth valve, and the measured gas in the test gas tank is discharged through the fifth valve;

S2.3. The pressure sensor records the air pressure value P ₂ ⁿ in the test piece after the first detection, n=1, and records the pressure values P ₁ and P ₂ ^{n, n=1} successively according to the pressure sensor, and the test gas tank The volume of V ₂ is used to calculate the volume V ₁ of the test piece, and the volume of the test gas tank is V ₂ for known data;

S2.4: The pressure sensor continuously measures the air pressure in the piece under test. If the pressure value in the piece under test is greater than 0Pa, repeat steps S2.2 and S2.3. If the pressure value in the piece under test is 0Pa, stop the detection. Calculate the concentration of the electrolyte at standard atmospheric pressure and room temperature.

Preferably, the normal temperature in the step S2.4 is 20°C, and the concentration value of the electrolyte is K ₂₀ ,

Among them, K ^m refers to the detection value of the last measurement of the PID sensor, and P ₂₀ refers to the air pressure value when the ambient temperature is 20 °C;

In the step S2.3, the volume V1 _of the tested part is calculated and obtained according to the gas equation, and the gas equation is:

(P ₁ *V ₁ )/T ₁ =[P ₂ ^{n, n=1} *(V ₁ +V ₂ )]/T ₂ ,

Among them, T1 is the temperature _of the gas in the DUT after standing in step S4, and T2 is the temperature of the gas in the DUT after the gas flows into the test gas tank for the first time in step S5. _In a short time, _{T1≈T 2} ;

Therefore, P ₁ *V ₁ =P ₂ ^{n, n=1} *(V ₁ +V ₂ ).

Adopting the technical scheme provided by the present invention, compared with the prior art, has the following beneficial effects:

1. In the present invention, an electrolyte leakage detection system is connected between the air supply system and the tested part. After use, each valve can be opened, and the PID sensor can be directly cleaned by the clean air generated by the air source in the air supply system. Cleaning function, PID sensor life is extended.

2. In the electrolyte leakage detection system involved in the present invention, a third valve is set in front of the PID sensor, and a test gas tank and a fifth valve are set at the rear. When testing electrolyte leakage, the third valve and the fifth valve are alternately switched on and off. , The PID sensor tests the gas temporarily stored in the test gas tank. Therefore, for each batch of gas, the PID sensor has sufficient time to detect, and the detection accuracy is higher, and the concentration of the electrolyte can also be calculated by calculation. size.

3. The method of the present invention for outputting low-pressure gas from a high-pressure gas source to a workpiece adopts two valves and a buffer gas tank, and realizes the inflation of the workpiece and precise air pressure control through the alternate on-off of the valve, and the production cost of the valve is low. Therefore, the production cost is greatly reduced; there is no need to perform any pretreatment on the structure of the tested part during testing, and the connection is directly connected through the gas injection port tooling, which is easy to operate; the gas injection pressure is automatically and accurately adjustable, reducing the impact on the airtight structure of the tested part. damage.

4. The present invention can also be configured with a humidity detection system, the humidity detection system is connected between the pressure sensor and the measured object, and the humidity detection system includes a fourth valve and a humidity sensor connected in series. Before the electrolyte leakage detection system detects the gas, first use the humidity detection system to detect the humidity of the gas, and then perform the electrolyte leakage detection after the humidity detection meets the requirements, so as to prevent the water vapor in the gas from causing damage to the PID sensor and further increase the service life of the PID sensor. .

Description of drawings

Fig. 1 is the structural representation of the electrolyte leakage detection device involved in the embodiment 1;

Fig. 2 is the structural representation of the electrolyte leakage detection device involved in the embodiment 2;

Fig. 3 is the structural representation of the electrolyte leakage detection device involved in embodiment 3;

FIG. 4 is a schematic structural diagram of the electrolyte leakage detection device involved in Example 4. FIG.

Icon description: 1-air source, 2-automatic drain, 3-inlet air pressure reducing valve, 4-precision pressure regulating valve, 5-first valve, 6-buffer gas tank, 7-second valve, 8-pressure Sensor, 9-test piece, 10-third valve, 11-PID sensor, 12-fourth valve, 13-humidity sensor, 14-muffler, 15-test gas tank, 16-fifth valve.

Detailed ways

In order to further understand the content of the present invention, the present invention is described in detail with reference to the embodiments. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

Example 1

As shown in FIG. 1 , the battery box electrolyte leakage detection device involved in the present embodiment includes an air supply system and an electrolyte leakage detection system respectively connected to the measured component.

The described air supply system includes an air source 1, a first valve 5 and a pressure sensor 8 which are connected in series in sequence. The pressure sensor 8 adopts the Mico universal pressure sensor MIK-P300, and the electrolyte leakage detection system is connected to the pressure sensor 8. Between the device under test 9, the electrolyte leakage detection system includes a third valve 10 and a PID sensor 11 connected in sequence, and the PID sensor 11 adopts a PID gas sensor from AMETEK MOCON Company in the United States.

The steps of using the above-mentioned battery box electrolyte leakage detection device to detect electrolyte leakage are as follows:

S1: Close the third valve 10, open the first valve 5, and the air source 1 inflates the DUT 9 until the pressure sensor 8 detects that the air pressure in the DUT 9 reaches the set value, close the first valve 5 and stand still At one end of the time, let the gas inside the DUT 9 fully mix with the injected air;

S2: Open the third valve 10, the mixed gas flows out from the measured component 9, and is discharged after passing through the PID sensor 11, and the PID sensor 11 detects whether there is electrolyte leakage;

S3: After the detection is completed, open the first valve 5 and the third valve 10, and the air source 1 directly blows air to the PID sensor 11 to clean the PID sensor 11.

Example 2

As shown in FIG. 2 , the battery box electrolyte leakage detection device involved in the present embodiment includes an air supply system and an electrolyte leakage detection system respectively connected to the tested component.

The air supply system includes an air source 1, a first valve 5 and a pressure sensor 8 that are connected in series, and the pressure sensor 8 is a Mico universal pressure sensor MIK-P300; the air source 1 and the first valve 5 are also connected in sequence. There are automatic drain 2, intake pressure reducing valve 3 and precision pressure regulating valve 4. The compressed gas generated by air source 1 will carry water vapor when it comes out, especially for air compressors that have not been drained for a long time, the water vapor content is very large, and automatic drainage is required. The function of the regulator 2 is to discharge the water vapor in the compressed air. The intake pressure reducing valve 3 adopts RPT balanced pressure reducing valve or RW stainless steel pressure reducer, and the precision pressure regulating valve 4 adopts ZDLN electronic double seat electric regulating valve or ZZYP type. Self-operated pressure regulating valve, the intake pressure reducing valve 3 is used to reduce the air pressure when the gas enters the air supply system, and the precision pressure regulating valve 4 is used to precisely control the air pressure in the air supply system. Accurately adjustable to reduce damage to the airtight structure of the test piece; the first valve 5 and the pressure sensor 8 are connected to the buffer gas tank 6 and the second valve 7 in turn, and the first valve 5 and the second valve 7 are alternately switched on and off , first buffer the gas generated by the gas source 1 in the buffer gas tank 6, and then fill the air in the buffer gas tank 6 into the DUT 9, the gas input in the DUT 9 is more stable, and the DUT 9 is further protected. , so that it is not damaged.

The electrolyte leakage detection system is connected between the pressure sensor 8 and the measured part 9, and the electrolyte leakage detection system includes a third valve 10 and a PID sensor 11 connected in sequence, and the PID sensor 11 adopts the PID gas of AMETEK MOCON Company in the United States. The gas outlet end of the PID sensor 11 is also provided with a muffler 14 to reduce the noise generated when the gas is discharged.

The steps of using the above-mentioned battery box electrolyte leakage detection device to detect electrolyte leakage are as follows:

S1.1: close the third valve 10 and the second valve 7, adjust the intake pressure reducing valve 3 and the precision pressure regulating valve 4, the gas source 1 first inflates the buffer gas tank 6, and the gas passes through the automatic drain 2 to remove water vapor;

S1.2: close the first valve 4 and open the second valve 7, the buffer gas tank 6 inflates the measured part 9, and the pressure sensor 8 detects the air pressure of the gas in the measured part 9;

S1.3: Determine whether the air pressure in the tested piece 9 detected by the pressure sensor 8 reaches the set value. If it does not reach the set value, repeat steps S1.1 and S1.2 to alternately turn on and off the first valve 5 and the first valve 5. Two valves 7, so that the air source 1 inflates the measured object 9 through the buffer gas tank 6 to reach the preset air pressure, if the set value is reached, close the first valve 5 and the second valve 7 and leave it for a period of time, let the measured object 9 The internal gas is fully mixed with the injected air;

S2: Open the third valve 10, the mixed gas flows out from the measured component 9, and is discharged after passing through the PID sensor 11, and the PID sensor 11 detects whether there is electrolyte leakage;

S3: After the detection is completed, open the first valve 5 and the third valve 10, and the air source 1 directly blows air to the PID sensor 11 to clean the PID sensor 11.

Compared with the embodiment 1, this embodiment adds an automatic drain 2, which can discharge the water vapor in the air generated by the air source, and reduces the damage caused by the water vapor to the PID sensor 11; The pressure valve 4 can accurately control the inflation pressure; the buffer gas tank 6 is added, and by alternately opening and closing the first valve 5 and the second valve 7, the gas source first inflates the buffer gas tank 6, and then the buffer gas tank 6 fills the The test piece 9 is inflated, and the test piece is inflated more stably, reducing the damage to the test piece 9 caused by the airflow.

Example 3

As shown in FIG. 3 , the tank electrolyte leakage detection device includes an air supply system and an electrolyte leakage detection system respectively connected to the tested piece.

The air supply system includes an air source 1, a first valve 5 and a pressure sensor 8 that are connected in series, and the pressure sensor 8 is a Mico universal pressure sensor MIK-P300; the air source 1 and the first valve 5 are also connected in sequence. There are automatic drain 2, intake pressure reducing valve 3 and precision pressure regulating valve 4. The compressed gas generated by air source 1 will carry water vapor when it comes out, especially for air compressors that have not been drained for a long time, the water vapor content is very large, and automatic drainage is required. The function of the regulator 2 is to discharge the water vapor in the compressed air. The intake pressure reducing valve 3 adopts RPT balanced pressure reducing valve or RW stainless steel pressure reducer, and the precision pressure regulating valve 4 adopts ZDLN electronic double seat electric regulating valve or ZZYP type. Self-operated pressure regulating valve, the intake pressure reducing valve 3 is used to reduce the air pressure when the gas enters the air supply system, and the precision pressure regulating valve 4 is used to precisely control the air pressure in the air supply system. Accurately adjustable to reduce damage to the airtight structure of the test piece; the first valve 5 and the pressure sensor 8 are connected to the buffer gas tank 6 and the second valve 7 in turn, and the first valve 5 and the second valve 7 are alternately switched on and off , first buffer the gas generated by the gas source 1 in the buffer gas tank 6, and then fill the air in the buffer gas tank 6 into the DUT 9, the gas input in the DUT 9 is more stable, and the DUT 9 is further protected. , so that it is not damaged.

The electrolyte leakage detection system is connected between the pressure sensor 8 and the measured part 9, and the electrolyte leakage detection system includes a third valve 10 and a PID sensor 11 connected in sequence, and the PID sensor 11 adopts the PID gas of AMETEK MOCON Company in the United States. The gas outlet end of the PID sensor 11 is also provided with a muffler 14 to reduce the noise generated when the gas is discharged.

The electrolyte leakage detection system is also equipped with a humidity detection system, the humidity detection system is connected between the pressure sensor 8 and the measured object 9, and the humidity detection system includes a fourth valve 12 and a humidity sensor 13 connected in series in sequence, and the humidity sensor 13 The HM1500LF temperature and humidity sensor is used, and the outlet end of the humidity detection system is also provided with a muffler 14. The outlet ends of the humidity detection system and the electrolyte leakage detection system can be connected to each other and share a muffler 14 to reduce the cost of the equipment.

The steps of using the above-mentioned battery box electrolyte leakage detection device to detect electrolyte leakage are as follows:

S1.1: close the third valve 10 and the second valve 7, adjust the intake pressure reducing valve 3 and the precision pressure regulating valve 4, the gas source 1 first inflates the buffer gas tank 6, and the gas passes through the automatic drain 2 to remove water vapor;

S1.2: close the first valve 4 and open the second valve 7, the buffer gas tank 6 inflates the measured part 9, and the pressure sensor 8 detects the air pressure of the gas in the measured part 9;

S1.3: Determine whether the air pressure in the tested piece 9 detected by the pressure sensor 8 reaches the set value. If it does not reach the set value, repeat steps S1.1 and S1.2 to alternately turn on and off the first valve 5 and the first valve 5. Two valves 7, so that the air source 1 inflates the measured object 9 through the buffer gas tank 6 to reach the preset air pressure, if the set value is reached, close the first valve 5 and the second valve 7 and leave it for a period of time, let the measured object 9 The internal gas is fully mixed with the injected air;

S2.1: Open the fourth valve 12, the mixed gas flows out from the DUT 9, and is discharged after passing through the fourth valve 12 and the humidity sensor 13. The humidity sensor 13 detects the humidity in the mixed gas. If the humidity is greater than the threshold, the mixed gas is Stop detection after emptying; if the humidity is less than the threshold, enter S2.2;

S2.2: close the fourth valve 12, open the third valve 10, the mixed gas flows out from the measured part 9, and then is discharged after passing through the PID sensor 11, and the PID sensor 11 detects whether there is electrolyte leakage;

S3: After the detection is completed, open the first valve 5 and the third valve 10, and the air source 1 directly blows air to the PID sensor 11 to clean the PID sensor 11.

Compared with the second embodiment, this embodiment further adds a humidity detection system. Before using the PID sensor 11 to detect the electrolyte leakage of the gas, the humidity detection system is used to detect the humidity of the mixed gas in the measured object 9 first. , The electrolyte leakage detection is carried out only after the humidity detection is combined with the requirements, and the PID sensor 11 is protected, the service life of the PID sensor 11 is increased, and the maintenance cost is reduced.

Example 4

As shown in FIG. 4 , the battery box electrolyte leakage detection device involved in the present embodiment includes an air supply system and an electrolyte leakage detection system respectively connected to the tested component.

The air supply system includes an air source 1, a first valve 5 and a pressure sensor 8 that are connected in series, and the pressure sensor 8 is a Mico universal pressure sensor MIK-P300; the air source 1 and the first valve 5 are also connected in sequence. There are automatic drain 2, intake pressure reducing valve 3 and precision pressure regulating valve 4. The compressed gas generated by air source 1 will carry water vapor when it comes out, especially for air compressors that have not been drained for a long time, the water vapor content is very large, and automatic drainage is required. The function of the regulator 2 is to discharge the water vapor in the compressed air. The intake pressure reducing valve 3 adopts RPT balanced pressure reducing valve or RW stainless steel pressure reducer, and the precision pressure regulating valve 4 adopts ZDLN electronic double seat electric regulating valve or ZZYP type. Self-operated pressure regulating valve, the intake pressure reducing valve 3 is used to reduce the air pressure when the gas enters the air supply system, and the precision pressure regulating valve 4 is used to precisely control the air pressure in the air supply system. Accurately adjustable to reduce damage to the airtight structure of the test piece; the first valve 5 and the pressure sensor 8 are connected to the buffer gas tank 6 and the second valve 7 in turn, and the first valve 5 and the second valve 7 are alternately switched on and off , first buffer the gas generated by the gas source 1 in the buffer gas tank 6, and then fill the air in the buffer gas tank 6 into the DUT 9, the gas input in the DUT 9 is more stable, and the DUT 9 is further protected. , so that it is not damaged.

The electrolyte leakage detection system is connected between the pressure sensor 8 and the measured part 9, and the electrolyte leakage detection system includes a third valve 10 and a PID sensor 11 connected in sequence, and the PID sensor 11 adopts the PID gas of AMETEK MOCON Company in the United States. The sensor, the electrolyte leakage detection system also includes a test gas tank 15 and a fifth valve 16, the test gas tank 15 and the fifth valve 16 are connected in series with the PID sensor 11 in turn, and the end of the electrolyte leakage detection system is also provided with a muffler 14 , used to reduce the noise generated when the gas is discharged.

The steps of using the above-mentioned battery box electrolyte leakage detection device to detect electrolyte leakage are as follows:

S1.1: close the third valve 10 and the second valve 7, adjust the intake pressure reducing valve 3 and the precision pressure regulating valve 4, the gas source 1 first inflates the buffer gas tank 6, and the gas passes through the automatic drain 2 to remove water vapor;

S1.2: close the first valve 4 and open the second valve 7, the buffer gas tank 6 inflates the measured part 9, and the pressure sensor 8 detects the air pressure of the gas in the measured part 9;

S1.3: Determine whether the air pressure in the tested piece 9 detected by the pressure sensor 8 reaches the set value. If it does not reach the set value, repeat steps S1.1 and S1.2 to alternately turn on and off the first valve 5 and the first valve 5. Two valves 7, so that the air source 1 inflates the measured object 9 through the buffer gas tank 6 to reach the preset air pressure, if the set value is reached, close the first valve 5 and the second valve 7 and leave it for a period of time, let the measured object 9 The internal gas is fully mixed with the injected air;

S2.1: The gas inside the tested object 9 is fully mixed with the injected air, and the pressure sensor 8 records the pressure value P ₁ ;

S2.2: Open the third valve 10 and close the fifth valve 16, and part of the gas inside the DUT 9 flows into the test gas tank 15 through the third valve 10. At this time, the pressure sensor 8 detects that the pressure value is P ₂ ⁿ , The PID sensor 11 detects the gas in the test gas tank, and the electrolyte concentration value detected this time is K ⁿ , where n is the current number of times the PID sensor 11 detects the gas;

S2.3: After the PID sensor 11 detects the gas in the test gas tank for a period of time, the third valve 10 is closed and the fifth valve 16 is opened, and the measured gas in the test gas tank 15 is discharged through the fifth valve 16;

S2.3. The pressure sensor records the air pressure value P ₂ ⁿ in the test piece 9 after the first detection, n=1, and records the pressure values P ₁ and P ₂ ^{n, n=1} successively according to the pressure sensor, and the test gas The volume of the tank 15 is V ₂ to calculate the volume V ₁ of the test piece, and the volume of the test gas tank 15 is V ₂ is known data. Before assembling the testing device, select the volume of the test gas tank 15 and the volume of the test piece V ₁ is calculated according to the gas equation, which is:

(P ₁ *V ₁ )/T ₁ =[P ₂ ^{n, n=1} *(V ₁ +V ₂ )]/T ₂ ,

Among them, T1 is the temperature _of the gas in the DUT after standing in step S4, and T2 is the temperature of the gas in the DUT after the gas flows into the test gas tank for the first time in step S5. _In a short time, _{T1≈T 2} ;

Therefore, P ₁ *V ₁ =P ₂ ^{n, n=1} *(V ₁ +V ₂ );

S2.4: The pressure sensor continuously measures the air pressure in the piece under test. If the pressure value in the piece under test is greater than 0Pa, repeat steps S2.2 and S2.3. If the pressure value in the piece under test is 0Pa, stop the detection. Calculate the concentration value of the electrolyte solution at standard atmospheric pressure and normal temperature, the normal temperature is 20°C, and the concentration value of the electrolyte solution is K ₂₀ ,

Among them, K ^m refers to the detection value of the last measurement of the PID sensor, and P ₂₀ refers to the air pressure value when the ambient temperature is 20 °C;

S3: After the detection is completed, open the first valve 5 and the third valve 10, and the air source 1 directly blows air to the PID sensor 11 to clean the PID sensor 11.

Compared with Embodiment 2, this embodiment can not only detect whether there is leakage of the electrolyte in the DUT 9, but also obtain the volume of the DUT and the concentration of electrolyte leakage through calculation.

In the above-mentioned Embodiments 1 to 4, each valve is controlled by the control system; the time when the gas inside the DUT 9 is fully mixed with the injected air is also controlled by the control system, which is set by the tester in the control system before the test.

The present invention has been described in detail above with reference to the embodiments, but the above contents are only preferred embodiments of the present invention and cannot be considered to limit the implementation scope of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention should still fall within the scope of the patent of the present invention.

Claims (10)

1. A battery box electrolyte leakage detection device is characterized in that: it comprises an air supply system and an electrolyte leakage detection system respectively connected with the tested part; the described air supply system comprises an air source connected in series, a first a valve and a pressure sensor for measuring the air pressure in the tested part; the electrolyte leakage detection system is respectively connected with the pressure sensor and the tested part, and the electrolyte leakage detection system comprises a third valve connected in sequence and a PID sensor for electrolyte leakage. 2 . The battery box electrolyte leakage detection device according to claim 1 , wherein the gas supply system further comprises a buffer gas tank and a second valve, and the buffer gas tank and the second valve are sequentially connected to the first valve 2 . and the pressure sensor. 3. The battery box electrolyte leakage detection device according to claim 1 is characterized in that: the electrolyte leakage detection system is further equipped with a humidity detection system, and the humidity detection system is respectively connected with the pressure sensor and the measured part, and the humidity The detection system includes a fourth valve connected in series and a humidity sensor for detecting the humidity of the gas in the tested object; the gas outlet ends of the electrolyte leakage detection system and the humidity detection system are connected to each other and are connected with a muffler. 4. battery box electrolyte leakage detection device according to claim 1, is characterized in that: described electrolyte leakage detection system also comprises test gas tank and the 5th valve, and test gas tank and the 5th valve are successively connected with PID sensor In series, a muffler is connected to the end of the electrolyte leakage detection system. 5 . The battery box electrolyte leakage detection device according to claim 1 , wherein an automatic drain for discharging water vapor in the gas generated by the gas source is also connected between the gas source and the first valve; the An intake pressure reducing valve and a precision pressure regulating valve are also connected between the air source and the first valve. 6. An electrolyte leakage detection method is characterized in that: it is realized based on a battery box electrolyte leakage detection device, and the battery box electrolyte leakage detection device comprises a gas supply system and an electrolyte leakage respectively connected with the tested part. a detection system; the air supply system includes an air source, a first valve, and a pressure sensor for measuring the air pressure in the tested piece in sequence; the electrolyte leakage detection system is respectively connected with the pressure sensor and the tested piece, The electrolyte leakage detection system includes a third valve connected in sequence and a PID sensor for detecting the electrolyte leakage of the tested component; the detection method includes the following steps: S1: Close the third valve, open the first valve, and the air source will inflate the DUT until the pressure sensor detects that the air pressure in the DUT reaches the set value, close the first valve and leave it for a period of time to let the DUT The internal gas is well mixed with the injected air; S2: Open the third valve, the mixed gas flows out from the tested part, and is discharged after passing through the PID sensor. The PID sensor detects whether there is electrolyte leakage; S3: After the detection is completed, open the first valve and the third valve, and the air source directly blows air to the PID sensor to clean the PID sensor. 7. The electrolyte leakage detection method according to claim 6, wherein the air supply system further comprises an automatic drain, an air intake pressure reducing valve, a precision pressure regulating valve, a buffer gas tank and a second valve, The automatic drain, the intake pressure reducing valve and the precision pressure regulating valve are sequentially connected between the air source and the first valve, and the buffer gas tank and the second valve are sequentially connected between the first valve and the pressure sensor. The step S1 is specifically Steps include: S1.1: Close the third valve and the second valve, adjust the intake pressure reducing valve and the precision pressure regulating valve, the gas source first inflates the buffer gas tank, and the gas passes through the automatic drain to remove water vapor; S1.2: Close the first valve and open the second valve, the buffer gas tank is inflated to the DUT, and the pressure of the gas in the DUT is detected by the pressure sensor; S1.3: Determine whether the air pressure in the tested piece detected by the pressure sensor reaches the set value. If it does not reach the set value, repeat steps S1.1 and S1.2 to alternately turn on and off the first valve and the second valve. Make the air source inflate the test piece through the buffer gas tank to reach the preset air pressure. If the set value is reached, close the first valve and the second valve and let it stand for a period of time, so that the gas inside the test piece is fully mixed with the injected air. 8. The electrolyte leakage detection method according to claim 6, wherein the electrolyte leakage detection system is further equipped with a humidity detection system, and the humidity detection system is respectively connected with the pressure sensor and the measured part, and the humidity detection system It includes a fourth valve connected in series in sequence and a humidity sensor for detecting the humidity of the gas in the device under test; the specific steps of step S2 include: S2.1: Open the fourth valve, the mixed gas flows out from the tested part, passes through the fourth valve and the humidity sensor, and then is discharged. The humidity sensor detects the humidity in the mixed gas. If the humidity is greater than the threshold value, the mixed gas is emptied and the detection is stopped. ; If the humidity is less than the threshold, enter S2.2; S2.2: Close the fourth valve and open the third valve, the mixed gas flows out from the tested part, and then is discharged after passing through the PID sensor. The PID sensor detects whether there is electrolyte leakage. 9. electrolyte leakage detection method according to claim 6, is characterized in that: described electrolyte leakage detection system also comprises test gas tank and the 5th valve, and test gas tank and the 5th valve are connected in series with PID sensor successively, The specific steps of step S2 include: S2.1: The gas inside the test piece is fully mixed with the injected air, and the pressure sensor records the pressure value P ₁ ; S2.2: Open the third valve and close the fifth valve, part of the gas inside the DUT flows into the test gas tank through the third valve, the pressure sensor detects the pressure value as P ₂ ⁿ , and the PID sensor detects the gas in the test gas tank. Carry out detection, the detection value is K ⁿ , and n is the current number of gas detection by the PID sensor; S2.3: After the PID sensor detects the gas in the test gas tank for a period of time, close the third valve and open the fifth valve, and the measured gas in the test gas tank is discharged through the fifth valve; S2.3. The pressure sensor records the air pressure value P ₂ ⁿ in the test piece after the first detection, n=1, and records the pressure values P ₁ and P ₂ ^{n, n=1} successively according to the pressure sensor, and the test gas tank The volume V ₂ is used to calculate the volume V ₁ of the test piece, and the volume of the test gas tank is V ₂ is the known data; S2.4: The pressure sensor continuously measures the air pressure in the piece under test. If the pressure value in the piece under test is greater than 0Pa, repeat steps S2.2 and S2.3. If the pressure value in the piece under test is 0Pa, stop the detection. Calculate the concentration of the electrolyte at standard atmospheric pressure and room temperature. 10. The electrolyte leakage detection method according to claim 9, wherein the normal temperature in the step S2.4 is 20°C, and the concentration value of the electrolyte is K ₂₀ ,

Among them, K ^m refers to the detection value of the last measurement of the PID sensor, and P ₂₀ refers to the air pressure value when the ambient temperature is 20 °C; In the step S2.3, the volume V1 _of the tested part is calculated and obtained according to the gas equation, and the gas equation is: (P ₁ *V ₁ )/T ₁ =[P ₂ ^{n, n=1} *(V ₁ +V ₂ )]/T ₂ , Among them, T1 is the temperature _of the gas in the DUT after standing in step S4, and T2 is the temperature of the gas in the DUT after the gas flows into the test gas tank for the first time in step S5. _In a short time, _{T1≈T 2} ; Therefore, P ₁ *V ₁ =P ₂ ^{n, n=1} *(V ₁ +V ₂ ).

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