Improved automatic airtightness detection equipment and method based on pressure system

Abstract

The invention discloses improved automatic air tightness detection equipment based on a pressure system, which comprises a pressure storage buffer bottle, and the outer surface of the pressure storage buffer bottle is sequentially coated with a temperature regulation control system and a heat preservation system from inside to outside; the pressure storage buffer bottle is connected with a main pipeline, and the main pipeline is sequentially connected with a pressure gauge, a differential pressure gauge, a self-checking pipeline, an exhaust pipeline, a pressurization assembly and a first stop valve in the direction away from the pressure storage buffer bottle. The other end of the main pipeline is communicated with a detected pipeline system; a balance valve is connected between pipelines at two ends of the differential pressure gauge; and the tail end of the self-checking pipeline is connected with a self-checking pressure storage bottle. The invention further discloses an improved automatic airtightness detection method based on the pressure system. The problems that in the prior art, due to the fact that the minimum resolution of the differential pressure gauge is in a dead zone, the airtightness detection result is inaccurate, and in the prior art, the detection time is long, and the precision is not high are solved.

Description

Technical Field

[0001] This invention belongs to the field of airtightness testing technology, specifically relating to an improved automatic airtightness testing device based on a pressure system, and also to an improved automatic airtightness testing method based on a pressure system. Background Technology

[0002] With the development of technology, the requirements for airtightness testing are becoming increasingly stringent in various fields, such as high-voltage equipment, aerospace, weaponry, and shipbuilding. Airtightness is a crucial indicator affecting success or failure. Especially for high-voltage equipment, airtightness directly impacts its insulation and service life. Before leaving the factory, airtightness is a key test indicator for the final performance of high-voltage equipment, and the quality of various third-party tests on the final equipment is closely related to airtightness. Existing airtightness testing equipment and methods all have certain limitations. For example, the patent with publication number CN115265956B (publication date 2025-03-14) proposes a device and method that can quantify the leakage level and form a quantitative standard. This quantitative standard serves as the quantitative measurement standard in the device's leak detection, guiding the judgment of the leak detection quantification results. However, for equipment or devices with high airtightness requirements, there are still certain drawbacks: when the minimum resolution of the existing high-precision differential pressure gauges used in the equipment or device is in the dead zone and cannot be identified, the detection results will be inaccurate. At the same time, in order to accurately measure the true airtightness, the airtightness testing time is extended indefinitely, which can cause the airtightness testing to seriously affect the entire production schedule. Summary of the Invention

[0003] The purpose of this invention is to provide an improved automatic airtightness testing device based on a pressure system, which solves the problems of inaccurate airtightness testing results due to the minimum resolution of the differential pressure gauge being in the dead zone, as well as the long testing time and low accuracy of the existing technology.

[0004] Another object of the present invention is to provide an improved automatic airtightness detection method based on a pressure system.

[0005] The technical solution adopted in this invention is an improved automatic airtightness testing device based on a pressure system, comprising a pressure storage buffer bottle, on the outer surface of which a temperature regulation and control system and a heat preservation system are sequentially attached and covered from the inside out; the pressure storage buffer bottle is connected to a main pipeline, on which a pressure gauge, a differential pressure gauge, a self-test pipeline, an exhaust pipeline, a pressurization component, and a first shut-off valve are sequentially connected in the direction away from the pressure storage buffer bottle; the other end of the main pipeline is used to connect to the pipeline system under test; a balancing valve is connected between the two pipelines of the differential pressure gauge; and a self-test pressure storage bottle is connected to the end of the self-test pipeline.

[0006] The invention is further characterized by: The booster assembly includes a booster line connected to the main pipeline, and a booster pump is connected to the end of the booster line.

[0007] The self-test pipeline is equipped with a second shut-off valve; the booster pipeline is equipped with a third shut-off valve; the exhaust pipeline is equipped with a pressure relief valve; and the end of the exhaust pipeline is connected to an exhaust muffler.

[0008] The temperature regulation and control system includes a flexible heating element and a control unit; the flexible heating element is a silicone heating sheet, a carbon fiber heating strip, or a micro-heating electric wire, which is uniformly wrapped around the outer surface of the pressure storage buffer bottle; the control unit is a PLC controller, which is electrically connected to the flexible heating element through wires.

[0009] The insulation system includes an inner flexible insulation layer and an outer insulation layer. The flexible insulation layer is aerogel felt, and the outer insulation layer is fiberglass cloth or PTFE coated cloth. The outer insulation layer is detachably connected to the outside of the flexible insulation layer by Velcro or stainless steel fasteners.

[0010] Another technical solution adopted in this invention is an improved automatic airtightness detection method based on a pressure system, which specifically includes the following steps: Step 1: Self-test; Step 1.1: Close the first shut-off valve, open the second shut-off valve and the balancing valve, and pressurize the main pipeline through the pressurization component until the rated pressure for airtight leak detection is reached; close the balancing valve, observe and record the pressure change value of the differential pressure gauge within the preset time; after the pressurization is completed and the temperature of the entire system pipeline and the pressure storage buffer tank is balanced with the ambient temperature, close the balancing valve and start leak detection of the system; Step 1.2: Initial temperature adjustment, start leak detection and dead zone avoidance; Step 1.3: During the detection period, continuously record the pressure changes of the differential pressure gauge; Step 1.4: Secondary temperature adjustment and endpoint recording; Step 1.5: Calculate the actual pressure leakage during the detection period to determine the airtightness of the equipment itself; Step 1.6: Open the pressure relief valve to depressurize the entire detection circuit and complete the equipment self-test.

[0011] Step 2: Test the airtightness of the connected pipeline system under inspection; Step 2.1: Open the first shut-off valve and the balancing valve, and close the pressure relief valve to pressurize the main pipeline until the pressure in the main pipeline reaches the rated pressure for airtight leak detection. During the process, monitor the system pressure in real time using a pressure gauge. After the pressurization is completed and the temperature of the entire system pipeline and the pressure storage buffer tank is balanced with the ambient temperature, close the balancing valve and begin leak detection of the system. Step 2.2: Initial temperature adjustment, start leak detection and dead zone avoidance; Step 2.3: During the detection period, continuously record the pressure changes of the differential pressure gauge; Step 2.4: Secondary temperature adjustment and endpoint recording; Step 2.5: Calculate the actual pressure leakage during the detection period; Step 2.6: Open the pressure relief valve to depressurize the entire test circuit and complete one airtightness test process.

[0012] Another feature of the technical solution of this invention is that: Step 2.1 involves pressurizing the main pipeline, including: When the airtightness test equipment has its own air source, open the first shut-off valve and pressurize the main pipeline through the pipeline under test until the pressure in the main pipeline reaches the rated pressure for airtightness test. When the airtightness test equipment has no air supply, open the third shut-off valve and start the booster pump to pressurize the main pipeline. After the pressure in the main pipeline reaches the rated pressure for airtightness testing, close the booster pump and the third shut-off valve.

[0013] Steps 1.2 and 2.2 involve initial temperature adjustment, initiating leak detection and dead zone avoidance, including: Close the balancing valve, and through the temperature regulation and control system surrounding the pressure storage buffer tank, adjust according to formula P. 初 / T 初 =P 终 / T 终 Adjust the temperature inside the pressure storage buffer bottle, where P 初 P 终 T represents the initial and final pressures, respectively. 初 T 终 The initial and final temperatures are in K; a small pressure change is generated inside the bottle, the amount of which is m1×(1 / 10)d, where d is the minimum resolution of the differential pressure gauge and m1 is the first multiplier coefficient. Observe the differential pressure gauge reading change. After confirming that it has jumped out of the dead zone, record the current pressure reading P1 and use this time as the start time of the airtightness test.

[0014] Steps 1.4 and 2.4, including secondary temperature adjustment and endpoint recording, include: Adjust the temperature again using the temperature control system according to formula P. 初 / T 初 =P 终 / T 终 Adjusting the temperature inside the pressure storage buffer bottle produces a small pressure change, the amount of which is m2×(1 / 10)d, where m2 is the second multiple coefficient; After observing the change in the differential pressure gauge reading, record the current pressure reading P2, and use this time as the end time of the airtightness test.

[0015] In steps 1.5 and 2.5, the actual pressure leakage during the detection period is calculated using the following formula: P = P2 - P1 - m2 × (1 / 10)d In the formula, P represents the actual pressure leakage.

[0016] The beneficial effects of this invention are: 1. Compared with the prior art, the improved automatic airtightness testing equipment and method based on the pressure system of this invention adds a temperature regulation control system and a heat preservation system covering the pressure storage buffer bottle. This can avoid the situation where the actual leakage of the airtight equipment / equipment being tested cannot be measured due to the dead zone of the differential pressure gauge. By regulating the temperature of the covering temperature regulation control system and the heat preservation system, it is ensured that the differential pressure gauge jumps out of the dead zone before measurement, thus ensuring the reliability and accuracy of the airtightness testing subsystem. 2. By adding a temperature regulation and control system and a heat preservation system that covers the pressure storage buffer bottle, the resolution of the measurement results is improved by 10 times, avoiding the situation where existing differential pressure gauge technology cannot meet the requirements of high airtightness detection.

[0017] 3. By adding a temperature regulation and control system and a heat preservation system to the outside of the pressure storage buffer bottle, the resolution of the differential pressure gauge is improved, and the actual situation of long-term airtightness testing of existing high-requirement airtightness equipment / equipment is improved. After the application of the equipment and method of this invention, the airtightness testing time of high-requirement airtightness equipment / equipment can be significantly reduced from the process perspective after accumulating a certain amount of experimental data. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the improved automatic airtightness testing device based on the pressure system of the present invention.

[0019] In the diagram: 1. Self-testing pressure storage bottle; 2. Exhaust pipeline; 3. Pressure storage buffer bottle; 4. Pressure gauge; 5. Differential pressure gauge; 6. Booster pump; 7. Booster pipeline; 8. Main pipeline; 9. Balancing valve; 10. Self-testing pipeline; 11. First shut-off valve; 12. Second shut-off valve; 13. Third shut-off valve; 14. Pressure relief valve; 15. Exhaust silencer; 16. Temperature regulation and control system; 17. Insulation system. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0021] Example 1 This embodiment provides an improved automatic airtightness testing device based on a pressure system, the specific structure of which is as follows: Figure 1As shown, the system includes a pressure storage buffer bottle 3. From the inside out, a temperature control system 16 and an insulation system 17 are sequentially attached and covered to the outer surface of the pressure storage buffer bottle 3. The pressure storage buffer bottle 3 is connected to a main pipeline 8. Along the direction away from the pressure storage buffer bottle 3, a pressure gauge 4, a differential pressure gauge 5, a self-test pipeline 10, an exhaust pipeline 2, a pressurization assembly, and a first shut-off valve 11 are sequentially connected to the main pipeline 8. The other end of the main pipeline 8 is used to connect to the pipeline system under test. The first shut-off valve 11 is installed at the end of the main pipeline 8 connected to the pipeline system under test, and is used to control the connection between the pipeline system under test and the main pipeline 8. The pressure gauge 4 is used to monitor the pressure on the main pipeline 8 in real time during pressurization and the pressure on the main pipeline 8 between the differential pressure gauge 5 and the pressure storage buffer bottle 3 after the balance valve 9 is closed. The balance valve 9 is connected between the two ends of the differential pressure gauge 5. The end of the self-test pipeline 10 is connected to a self-test pressure storage bottle 1.

[0022] Example 2 Based on Example 1, the differential pressure gauge 5 can be a micro differential pressure gauge, such as a micro differential pressure transmitter or a micro differential pressure digital gauge. The range of the differential pressure gauge 5 is selected according to the actual test conditions, such as 500Pa, 1kPa, 2.5kPa or 10kPa. The accuracy class is selected as 0.05 or other classes that meet the measurement requirements, and the pressure resistance meets the highest pressure resistance during the airtightness test.

[0023] Pressure gauge 4 can be selected from pressure transmitters or digital pressure gauges, etc. The range of pressure gauge 4 is selected according to the actual leak detection pressure, or according to the actual stamping pressure, the range can be selected as 6MPa, 10MPa or 25MPa, etc. The range of pressure gauge 4 needs to match the actual stamping pressure, and the actual stamping pressure should be about 60% of the full range of pressure gauge. The accuracy class of pressure gauge 4 should be selected as 0.05 class or other class that meets the measurement requirements.

[0024] The volume of the pressure storage buffer bottle 3 should be sufficient to meet the pressure balance buffering requirement. It can be used as a standard pressure storage source and can be 2L. The material of the pressure storage buffer bottle 3 should be less affected by temperature and be used as a leak-proof standard. The booster pump 6's booster range is selected based on the actual stamping pressure range.

[0025] Example 3 Based on Example 1, in order to enable multiple tests on the pipeline system under test without disassembling the connection between the main pipeline 8 and the pipeline system under test, an exhaust pipeline 2 is provided between the differential pressure gauge 5 and the first shut-off valve 11. A pressure relief valve 14 is provided on the exhaust pipeline 2. One end of the exhaust pipeline 2 is connected to the main pipeline 8, and the other end is connected to an exhaust muffler 15 to reduce the aerodynamic noise generated during the exhaust process.

[0026] To enable self-testing of the device of the present invention and eliminate the influence of device-specific factors on the airtightness of the tested pipeline system, a self-testing pipeline 10 is installed between the differential pressure gauge 5 and the first shut-off valve 11. One end of the self-testing pipeline 10 is connected to the main pipeline 8, and the other end is connected to the self-testing pressure storage bottle 1. A second shut-off valve 12 is installed on the self-testing pipeline 10.

[0027] To ensure that the pressure in the main pipeline 8 is the same as the rated pressure in the pipeline system under test and to achieve the self-test function, a booster pipeline 7 is set up. One end of the booster pipeline 7 is connected to the main pipeline 8, and the other end is connected to the booster pump 6. The third shut-off valve 13 is installed on the booster pipeline 7. When the pressure in the main pipeline 8 does not reach the rated pressure in the pipeline system under test, the booster pump 6 is used to boost the pressure.

[0028] Example 4 Based on Example 3, to avoid inaccurate airtightness detection results due to the differential pressure gauge's minimum resolution being in a dead zone, a temperature regulation control system 16 and a heat preservation system 17 are sequentially attached and wrapped around the outer surface of the pressure storage buffer bottle 3 from the inside out. The temperature is adjusted by utilizing the relationship between temperature regulation and pressure change to achieve pressure jumps. Wherein: The temperature control system 16 includes a flexible heating element and a control unit. The flexible heating element is a silicone heating sheet, a carbon fiber heating strip, or a micro-heating electric wire. The flexible heating element is uniformly covered on the outer surface of the pressure storage buffer bottle 3, and the coverage area is at least 80% of the outer surface area of ​​the pressure storage buffer bottle 3. The control unit is a PLC controller, which is electrically connected to the flexible heating element through wires. The PLC controller has a built-in heating program.

[0029] The thermal insulation system 17 includes an inner flexible insulation layer and an outer insulation layer. The flexible insulation layer is an aerogel felt with a thickness of 20-25mm, and the outer insulation layer is a glass fiber cloth or PTFE coated cloth with a thickness of 5-8mm. The outer insulation layer is detachably connected to the outside of the flexible insulation layer by Velcro or stainless steel fasteners.

[0030] Example 5 This embodiment provides an improved automatic airtightness testing method based on a pressure system, using the improved automatic airtightness testing equipment based on a pressure system as described in Embodiment 4. Specifically, it includes the following steps: Before use, all valves inside the equipment are closed, and the pipeline system under test is connected to the main pipeline 8.

[0031] Step 1: Self-test; Step 1.1: Close the first shut-off valve 11, open the second shut-off valve 12 and the balance valve 9, and pressurize the main pipeline 8 through the pressurization assembly until the rated pressure for airtightness detection is reached; close the balance valve 9, observe and record the pressure change value of the differential pressure gauge 5 within the preset time. After the pressurization is complete and the temperature of the entire system pipeline and pressure buffer tank reaches the ambient temperature, close the balancing valve 9 and begin leak detection of the system. Step 1.2: Initial temperature adjustment, initiation of leak detection and dead zone avoidance, including: Close the balancing valve, and through the temperature regulation and control system 16 covering the pressure buffer tank, according to formula P... 初 / T 初 =P 终 / T 终 Adjust the temperature inside the pressure storage buffer bottle 3, where P 初 P 终 These represent the initial and final pressures, respectively. Since the overall system pressure change is relatively small, P is used in the calculation process. 初 Take the pressure gauge reading. T 初 T 终 The initial and final temperatures are in Kelvin. A small pressure change is generated inside the bottle, typically adjusted in increments of 1 / 10 of the differential pressure gauge's resolution. The pressure change is m1 × (1 / 10)d, where d is the minimum resolution of the differential pressure gauge and m1 is the first multiplier. Observe the differential pressure gauge reading change. After confirming that it has jumped out of the dead zone, record the current pressure reading P1 and use this time as the start time of the airtightness test.

[0032] Step 1.3: During the detection period, continuously record the pressure changes of the differential pressure gauge; Step 1.4: Secondary temperature adjustment and endpoint recording, including: The temperature is then adjusted again via the temperature control system 16 according to formula P. 初 / T 初 =P 终 / T 终 Adjusting the temperature inside the pressure storage buffer bottle produces a small pressure change, the amount of which is m2×(1 / 10)d, where m2 is the second multiple coefficient; After observing the change in the differential pressure gauge reading, record the current pressure reading P2, and use this time as the end time of the airtightness test.

[0033] Step 1.5: Calculate the actual pressure leakage during the detection period to determine the airtightness of the equipment itself; Calculate using the following formula: P = P2 - P1 - m2 × (1 / 10)d In the formula, P represents the actual pressure leakage.

[0034] Based on industry standards and actual needs, the airtightness of the equipment is determined by the value of P.

[0035] Step 1.6: Open the pressure relief valve 14 to depressurize the entire detection circuit and complete the equipment self-test. If the equipment does not meet the airtightness requirements, return it for maintenance.

[0036] Example 6: After the equipment self-test is completed, perform step 2 to test the airtightness of the pipeline system under test: Step 2.1: Open the first shut-off valve 11 and the balance valve 9, and close the pressure relief valve 14 to pressurize the main pipeline 8 until the pressure in the main pipeline reaches the rated pressure for airtightness testing. During the process, the system pressure is monitored in real time by the pressure gauge 4. After the pressurization is complete and the temperature of the entire system pipeline and pressure buffer tank reaches the ambient temperature, close the balancing valve 9 and begin leak detection of the system. Step 2.2: Initial temperature adjustment, initiation of leak detection and dead zone avoidance, including: Close the balancing valve, and through the temperature regulation and control system 16 covering the pressure buffer tank, according to formula P... 初 / T 初 =P 终 / T 终 Adjust the temperature inside the pressure storage buffer bottle 3, where P 初 P 终 T represents the initial and final pressures, respectively. 初 T 终 The initial and final temperatures are in K; a small pressure change is generated inside the bottle, the amount of which is m1×(1 / 10)d, where d is the minimum resolution of the differential pressure gauge and m1 is the first multiplier coefficient. Observe the differential pressure gauge reading change. After confirming that it has jumped out of the dead zone, record the current pressure reading P1 and use this time as the start time of the airtightness test.

[0037] Step 2.3: During the detection period, continuously record the pressure changes of the differential pressure gauge; Step 2.4: Secondary temperature adjustment and endpoint recording; The temperature is then adjusted again via the temperature control system 16 according to formula P. 初 / T 初 =P 终 / T 终 Adjusting the temperature inside the pressure storage buffer bottle produces a small pressure change, the amount of which is m2×(1 / 10)d, where m2 is the second multiple coefficient; After observing the change in the differential pressure gauge reading, record the current pressure reading P2, and use this time as the end time of the airtightness test.

[0038] Step 2.5: Calculate the actual pressure leakage during the detection period using the following formula: P = P2 - P1 - m2 × (1 / 10)d In the formula, P represents the actual pressure leakage.

[0039] Step 2.6: Open the pressure relief valve 14 to depressurize the entire test circuit and complete one airtightness test process.

[0040] This invention relates to an improved automatic airtightness testing device and method based on pressure systems, particularly suitable for airtightness testing of high-pressure (voltage) equipment. By employing a temperature regulation and insulation system encasing the pressure storage buffer bottle, it avoids the situation where the dead zone of the differential pressure gauge prevents the measurement of the actual leakage of the tested airtightness equipment / equipment. Simultaneously, it improves the resolution of the measurement results by 10 times, overcoming the limitations of existing differential pressure gauge technology in meeting high-requirement airtightness testing needs. Through the device and method of this invention, after accumulating sufficient experimental data, the airtightness testing time for high-requirement airtightness equipment / equipment can be significantly reduced, production schedules can be accelerated, and a basis for the formulation of airtightness standards can be provided.

Claims

1. An improved automatic air tightness detection apparatus based on a pressure system, characterized in that, The pressure storage buffer bottle (3) is connected with a main pipeline (8), the main pipeline (8) is sequentially connected with a pressure gauge (4), a differential pressure pressure gauge (5), a self-checking pipeline (10), an exhaust pipeline (2), a pressure increasing assembly and a first stop valve (11) in the direction away from the pressure storage buffer bottle (3); the other end of the main pipeline (8) is used for connecting a pipeline system to be checked; the differential pressure pressure gauge (5) is connected with a balance valve (9) between the pipelines at two ends; the self-checking pipeline (10) is connected with a self-checking pressure storage bottle (1) at the end.

2. The improved automatic air tightness detection apparatus based on pressure system according to claim 1, wherein, The pressure increasing assembly comprises a pressure increasing pipeline (7) connected to the main pipeline (8), and the pressure increasing pipeline (7) is connected with a pressure increasing pump (6) at the end.

3. The improved automatic air tightness detection apparatus based on pressure system according to claim 2, wherein, The self-checking pipeline (10) is provided with a second stop valve (12); the pressure increasing pipeline (7) is provided with a third stop valve (13); the exhaust pipeline (2) is provided with a pressure relief valve (14); and the exhaust pipeline (2) is connected with an exhaust silencer (15) at the end.

4. The improved automatic air tightness detection apparatus based on pressure system of claim 1, wherein, The temperature adjusting control system (16) comprises a flexible heating element and a control unit; the flexible heating element is a silica gel heating sheet or a carbon fiber heating belt or a micro heating wire, which is uniformly coated on the outer surface of the pressure storage buffer bottle (3); and the control unit is a PLC controller, which is electrically connected with the flexible heating element through wires.

5. The improved automatic air tightness detection apparatus based on pressure system of claim 1, wherein, The heat preservation system (17) comprises a flexible heat insulation layer and an outer heat preservation layer from inside to outside; the flexible heat insulation layer is aerogel felt, and the outer heat preservation layer is glass fiber cloth or PTFE coating cloth; and the outer heat preservation layer is detachably connected to the outside of the flexible heat insulation layer through magic tape or stainless steel buckle.

6. The improved automatic air tightness detection method based on pressure system of claim 1, wherein, The improved automatic air tightness detection equipment based on the pressure system is used, and specifically comprises the following steps: Step 1: self-checking; Step 1.1: closing the first stop valve (11), opening the second stop valve (12) and the balance valve (9), increasing the pressure in the main pipeline (8) through the pressure increasing assembly until the rated pressure of the air tightness leak detection is reached; closing the balance valve (9), observing and recording the pressure change value of the differential pressure pressure gauge (5) within a preset time; after the temperature of the entire system pipeline and the pressure storage buffer tank is balanced with the ambient temperature, the balance valve (9) is closed to start the leak detection of the system; Step 1.2: first temperature adjustment, starting leak detection and dead zone avoidance; Step 1.3: continuously recording the pressure change of the differential pressure pressure gauge within the detection time period; Step 1.4: secondary temperature adjustment and end recording; Step 1.5: calculating the actual pressure leakage amount within the detection time period to judge the air tightness of the equipment itself; Step 1.6: opening the pressure relief valve (14) to depressurize the entire detection circuit, and completing the self-checking of the equipment; Step 2: air tightness detection of the pipeline system to be checked; Step 2.1: open the first stop valve (11), balance valve (9), close the pressure relief valve (14), pressurize the main pipeline (8) until the pressure in the main pipeline reaches the rated pressure of the leak detection, and monitor the system pressure in real time through the pressure gauge (4) during the process; after the pressurization is completed, the system pipeline and the pressure storage buffer tank temperature are balanced with the ambient temperature, the balance valve (9) is closed, and the system is started for leak detection; Step 2.2: first temperature adjustment, start leak detection and dead zone avoidance; Step 2.3: continuously record the pressure change of the differential pressure gauge during the detection period; Step 2.4: secondary temperature adjustment and end point recording; Step 2.5: calculate the actual pressure leakage during the detection period; Step 2.6: open the pressure relief valve (14) to depressurize the entire detection circuit and complete the gas tightness detection process.

7. The improved automatic air tightness detection method based on pressure system of claim 6, wherein, The pressurization of the main pipeline (8) in step 2.1 includes: When the gas tightness device being detected has its own gas source, open the first stop valve (11) to charge the main pipeline (8) through the pipeline being detected to pressurize until the pressure in the main pipeline reaches the rated pressure of the leak detection; When the gas tightness device being detected has no gas source, open the third stop valve (13) and start the pressurizing pump (6) to pressurize the main pipeline (8). After the pressure in the main pipeline reaches the rated pressure of the leak detection, close the pressurizing pump (6) and the third stop valve (13).

8. The improved automatic air tightness detection method based on pressure system of claim 6, wherein, The first temperature adjustment, start leak detection and dead zone avoidance in step 1.2 and step 2.2 include: Close the balance valve, through the temperature adjustment control system (16) of the pressure storage buffer tank outer package, according to the formula P 初 / T 初 =P 终 / T 终 Adjust the temperature in the pressure storage buffer bottle (3), wherein P 初 , P 终 respectively represent the initial and final pressure; T 初 , T 终 are the initial and final temperatures, units are K; a small pressure change is generated in the bottle, and the pressure change amount is m1×(1 / 10)d, wherein d is the minimum resolution of the differential pressure gauge, and m1 is the first multiple coefficient; Observe the jump of the differential pressure gauge value, confirm that it jumps out of the dead zone, record the current pressure value P1, and take this time as the start time of the gas tightness detection.

9. The improved automatic air tightness detection method based on pressure system of claim 8, wherein, The secondary temperature adjustment and end point recording in step 1.4 and step 2.4 include: The temperature in the pressure storage buffer bottle is adjusted again by the temperature adjustment control system (16) according to the formula P 初 / T 初 =P 终 / T 终 The temperature in the pressure storage buffer bottle is adjusted again by the temperature adjustment control system (16) according to the formula P After observing the jump of the differential pressure gauge value, record the current pressure value P2, and take this time as the end time of the gas tightness detection.

10. The improved automatic air tightness detection method based on pressure system of claim 9, wherein, The calculation of the actual pressure leakage during the detection period in step 1.5 and step 2.5 is calculated according to the following formula: P = P2 - P1 - m2 x (1 / 10) d In the formula, P represents the actual pressure leakage.

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