Airtightness leak detection system and verification method thereof

Abstract

The invention discloses an airtight leakage detection system and a verification method thereof, and relates to the technical field of product leakage detection. According to the airtight leak detection system and the verification method thereof, the airtight leak detection system comprises a workshop air interface, at least one tested product, a bubble observation window, an exhaust electromagnetic valve, an isolation electromagnetic valve, a zero setting electromagnetic valve, a differential pressure sensor, a rapid exhaust port, a zero setting point and a differential pressure air interface, the interface is designed according to the specific detection requirements of the structure, material, thickness, shape and the like of a product, the volume, material, thickness, shape, pipeline length and internal structure of the bubble observation window containing the pure water container are matched with those of the detected product, the automation degree is high, automation of the leakage detection process is achieved, manual intervention is reduced, and the detection efficiency is improved. The detection efficiency and the data accuracy are improved, the precision is high, the pressure difference change is monitored in real time through the sensitive differential pressure gauge, and the leakage condition can be accurately judged.

Description

Technical Field

[0001] The present invention relates to the technical field of product leakage detection, and in particular to an airtight leakage detection system and a verification method thereof. Background Art

[0002] At present, domestic commercial aerospace is experiencing an unprecedented leap-forward development opportunity, and the airtightness detection research of its supporting pipelines, valves and other products has a broad and in-depth significance in promoting innovation. In the product production process, in order to ensure product quality, it is often necessary to conduct leakage detection on the product.

[0003] Traditional methods mostly use the bubble method, which is to judge whether there is a leak by manually observing the number of bubbles at the product outlet within a certain period of time. This method has the disadvantages of strong subjectivity, low efficiency, and inaccurate data recording. Especially in application scenarios that require high-precision detection, the limitations of the bubble method are particularly obvious. Summary of the invention

[0004] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide an airtight leak detection system and a verification method thereof, which can solve the problem that the traditional method mostly adopts the bubble method, that is, manually observing the number of bubbles at the product outlet end within a certain period of time to judge whether there is a leak. This method has the disadvantages of strong subjectivity, low efficiency, and inaccurate data recording.

[0005] To achieve the above object, the present invention provides the following technical solutions: an airtight leak detection system, comprising a workshop air interface, a product to be tested, a bubble observation window, an exhaust solenoid valve, an isolation solenoid valve, a zeroing solenoid valve, a differential pressure sensor, a quick exhaust port, a zeroing point and a differential pressure to air port;

[0006] Among them, at least one of the tested products is connected to the gas of the workshop air interface, and its interface is designed according to the specific testing requirements such as the structure, material, thickness and shape of the product;

[0007] Among them, a bubble observation window containing a pure water container, whose volume, material, thickness, shape, pipe length and internal structure all match those of the product being tested, and has been verified to be leak-free, is used as a reference observation during the test process, i.e., an intuitive aid for counting bubbles by eye;

[0008] Wherein, the pipeline after the tested product is inserted into the water of a pure water container with a bubble observation window;

[0009] Among them, the three solenoid valves (SV1, SV2 and SV3) are respectively the exhaust solenoid valve, the isolation solenoid valve and the zeroing solenoid valve. The exhaust solenoid valve is used to open and close the quick exhaust and is connected to the quick exhaust port. The isolation solenoid valve controls the tested product to pass through the pure water container. If there are bubbles escaping, it will connect and disconnect with the differential pressure sensor and connect the differential pressure to the air port. The zeroing solenoid valve sets and clears the pressure difference and is connected to the zeroing point.

[0010] Among them, a sensitive differential pressure sensor, whose measurement accuracy meets the detection requirements, is used to monitor and record in real time whether the tested product is leaking, resulting in pressure differences inside and outside the system.

[0011] Preferably, in order to improve the high-precision sensitivity of the detection, a vacuum aspirator is added in parallel with the quick exhaust port, the zero point, the differential pressure to air port, etc., and a vacuum solenoid valve with ultra-high sealing performance is used to control the connection and disconnection of the vacuum aspirator to achieve the construction and maintenance of the negative pressure environment inside the container;

[0012] Among them, the vacuum extractor adopts a vacuum pump or a vacuum generator, etc., which is used to establish and maintain the required negative pressure environment in the pipeline behind the tested product and inside the pure water container.

[0013] Preferably, a temperature sensor is added and installed near or inside the tested product and the pure water container to monitor and record the ambient temperature changes during the test process to correct the influence of temperature on the pressure measurement;

[0014] Among them, the computer data acquisition and processing system is connected to the differential pressure gauge and temperature sensor, which is used to receive and process the test data, perform data analysis and judgment through preset algorithms, determine the leakage of the tested product, and output the test results or alarm signals.

[0015] Preferably, one or more brackets or fixtures for fixing and supporting the tested product and the pure water container to ensure the stability of the container during the test process;

[0016] Among them, a calibration device, including a standard leak, is used to calibrate the system before testing to ensure that the measurement accuracy of the differential pressure gauge and the detection capability of the system meet the preset standards.

[0017] Preferably, the tested product and the pure water container are placed under the same environmental conditions for testing to reduce the influence of external environmental factors such as temperature and atmospheric pressure on the test results;

[0018] The system also includes one or more safety valves, such as an exhaust solenoid valve, which is installed behind the tested product and the pure water container to automatically release pressure when overpressure occurs during the detection process to ensure the safety of the system, especially to protect the precision differential pressure sensor and prevent damage due to overpressure.

[0019] Preferably, the vacuum solenoid valves (SV1, SV2 and SV3) are opened, the vacuum aspirator is started, and the tested product and the pure water container are vacuumized until a preset negative pressure value is reached;

[0020] Among them, the vacuum solenoid valves (SV1, SV2 and SV3) are closed, and the differential pressure sensor, i.e., the differential pressure gauge, starts to monitor and record the pressure difference inside and outside the tested product in real time;

[0021] Among them, start timing and record the pressure difference change data during the detection time;

[0022] Among them, the computer data acquisition and processing system receives data from the differential pressure gauge and temperature sensor, performs data analysis and judgment, determines the leakage situation of the tested product according to the preset leakage judgment standard, outputs the test results or alarm signals, and performs corresponding processing on the tested product according to the test results.

[0023] Preferably, the system is calibrated using a calibration device before each test to ensure that the measurement accuracy of the differential pressure sensor, i.e., the differential pressure gauge, and the detection capability of the system meet preset standards;

[0024] Among them, during the detection process, the environmental temperature changes are monitored in real time, and the measurement results of the differential pressure sensor, i.e., the differential pressure gauge, are corrected according to the data of the temperature sensor;

[0025] Among them, the computer self-check and alarm processing include the connection air tightness and working status of the differential pressure gauge, pure water container, test container, vacuum solenoid valve, and vacuum aspirator;

[0026] Among them, the leak detection method of the leak detection system includes establishing a pressure difference environment, real-time monitoring of pressure difference changes, data analysis and judgment steps, so as to improve the accuracy and efficiency of leak detection.

[0027] Preferably, the bubble observation window of the pure water container can be eliminated, and the pipeline is directly connected to improve the portability of the system;

[0028] Among them, in this method, the pipeline acts as a container, and the smaller the container volume, the higher the sensitivity and the higher the resolution;

[0029] Among them, its volume size can be changed under a certain volume by testing a bubble, and the differential pressure sensor can be calibrated by using a standard leak to calibrate the change in the negative pressure value of a bubble.

[0030] Preferably, the workshop air interface is connected to a 0-30Mpa pressurized pipeline to meet the requirements of the tested product;

[0031] The leakage rate of the tested product is determined by Q=△P / △T*V, where Q is the total leakage rate of the container; V is the volume of the tested product; △P is the pressure change value; △T is the detection time, which is usually carried out according to the general leakage curve B. If there is a large leakage, it is handled according to the alarm of the large leakage curve A;

[0032] △P—pressure change value is generally between 0 and 1000Pa, △T—detection time is generally determined according to the specific test product requirements, such as 3 minutes.

[0033] Preferably, a method for verifying an airtight leak detection system comprises the following steps:

[0034] S1: Establish a reference pressure environment: First, use a vacuum solenoid valve and a vacuum extractor (such as a vacuum pump) to evacuate the inside of the tested product (test container) and a known leak-free standard container (pure water container) to a certain negative pressure state. This is done to ensure that the internal pressures of the two containers are at a known and as close to a reference level as possible before the test begins.

[0035] S2: Pressure balance and monitoring: After the vacuum is completed, the solenoid valve is closed. At this time, a certain negative pressure should be maintained inside the two containers, and theoretically the pressures of the two should be equal (or very close), so the differential pressure gauge will display zero (or a very small deviation, depending on the accuracy of the differential pressure gauge). Next, the system enters the monitoring stage, and the differential pressure gauge begins to monitor the pressure difference between the two containers in real time.

[0036] S3: Leak detection: If there is a leak in the product (container) being tested, then over time, external gases (such as air) will gradually penetrate into the interior of the container, causing the internal pressure to gradually rise. Since the standard container (or pure water container) is sealed, its internal pressure remains basically unchanged, so a pressure difference will be generated between the inside and outside of the system. This pressure difference will be captured and recorded by the sensitive differential pressure gauge.

[0037] S4: Data analysis and judgment: The computer data acquisition and processing system receives the data from the differential pressure gauge, processes and analyzes it, and by comparing the changes in the pressure difference during the test, the system can determine whether there is a leak in the tested container and the severity of the leak. In some cases, the system can also automatically issue an alarm or stop testing based on the preset threshold.

[0038] S5: Calibration and verification: In order to ensure the accuracy and reliability of the leak detection system, it is usually necessary to calibrate the system using a standard leak hole. By measuring the change in the pressure difference output by the system under specific conditions (such as known leak rate and detection time), it can be verified whether the detection capability of the system meets the requirements;

[0039] Whether it meets the requirements depends on the specific test product requirements. For example, if there are less than 3 bubbles within 3 minutes, it is qualified. The system standard volume (fixed tube length) is taken and the pressure increase is about 300Pa. Otherwise, it is considered unqualified.

[0040] S6: The principle of the automatic static differential pressure boost leak detection system is to detect leaks by monitoring the pressure difference between the container being tested and the standard container. This method has the advantages of high automation, high accuracy, and strong data traceability, and is widely used in situations where high-precision leak detection is required.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] (1) The airtight leak detection system has a high degree of automation, which realizes the automation of the leak detection process, reduces manual intervention, and improves detection efficiency and data accuracy.

[0043] (2) The airtight leak detection system has high accuracy. It can accurately determine the leakage situation by real-time monitoring of the pressure difference change through a sensitive differential pressure gauge. It is suitable for scenarios with high requirements for detection accuracy.

[0044] (3) The airtight leak detection system has traceable data. The computer automatically collects and records data, which is convenient for subsequent analysis and traceability, and improves the standardization of production management.

[0045] (4) This airtight leak detection verification method has strong environmental adaptability. By keeping the two containers under the same environmental conditions for testing, the impact of external factors such as temperature changes on the test results is effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0047] Figure 1 A schematic diagram of the system principle of an airtight leak detection system and a verification method thereof according to the present invention;

[0048] Figure 2 A schematic diagram of the total leakage and degassing rate of a container in an airtight leak detection system and a verification method thereof according to the present invention.

[0049] Figure symbols: 0, workshop air interface; 1, tested product; 2, bubble observation window; 3, exhaust solenoid valve; 4, isolation solenoid valve; 5, zeroing solenoid valve; 6, differential pressure sensor; 7, quick exhaust port; 8, zeroing point; 9, differential pressure to air port; A, larger leakage curve; B, general leakage curve. DETAILED DESCRIPTION

[0050] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0051] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0052] In the description of the present invention, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0053] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0054] See also Figure 1-2 The present invention provides a technical solution: an airtight leak detection system and a verification method thereof, comprising an air interface 0, a tested product 1, a bubble observation window 2, an exhaust solenoid valve 3, an isolation solenoid valve 4, a zeroing solenoid valve 5, a differential pressure sensor 6, a quick exhaust port 7, a zeroing point 8, a differential pressure to air port 9, and a matching temperature sensor, a computer data acquisition and processing system (not shown), etc.;

[0055] Among them, at least one tested product 1 is connected to the gas of the workshop air interface 0, and its interface is designed according to the specific testing requirements such as the structure, material, thickness and shape of the product;

[0056] Among them, a bubble observation window 2 containing a pure water container, whose volume, material, thickness, shape, pipeline length and internal structure all match those of the tested product 1, and has been verified to be in a leak-free state, is used as a reference observation during the detection process, that is, an intuitive aid for counting bubbles by eye; the pipeline behind the tested product 1 is inserted into the water of the pure water container 2 with the bubble observation window;

[0057] Among them, three solenoid valves (SV1, SV2 and SV3) are respectively an exhaust solenoid valve 3, an isolation solenoid valve 4, and a zeroing solenoid valve 5. The exhaust solenoid valve 3 is used for opening and closing the quick exhaust, and is connected to the quick exhaust port 7; the isolation solenoid valve 4 controls the tested product 1 to pass through the pure water container 2. If there are bubbles escaping, it will be connected and disconnected with the differential pressure sensor 6, and the connected differential pressure is to the air port 9; the zeroing solenoid valve 5 sets and clears the pressure difference, and is connected to the zeroing point 8;

[0058] Among them, a sensitive differential pressure sensor 6, whose measurement accuracy meets the detection requirements, is used to monitor and record in real time whether the tested product 1 leaks and causes the pressure difference inside and outside the system;

[0059] like Figure 1 As shown, the leak detection process is as follows:

[0060] First, the workshop air interface 0 is connected to the 0-30Mpa charging pipeline to meet the requirements of the tested product 1; the exhaust solenoid valve 3, the isolation solenoid valve 4, and the zeroing solenoid valve 5 are opened in sequence to connect the tested container 1 (product) with the standard container (or pure water container), and the internal and external pressures of the system are kept in a balanced state. Subsequently, the exhaust solenoid valve 3, the isolation solenoid valve 4, and the zeroing solenoid valve 5 are closed in sequence. At this time, the differential pressure gauge displays zero differential pressure, and the isolation solenoid valve 3 is opened to start timing. If there is a leak in the tested container (product), as the bubbles overflow, the internal pressure gradually rises, and a pressure difference is formed between the container and the standard container. The pressure difference is monitored and recorded in real time by a sensitive differential pressure gauge. The computer data acquisition and processing system receives the data from the differential pressure gauge, and performs curve drawing and data analysis to determine the leakage situation.

[0061] Furthermore, in order to improve the high-precision sensitivity of the detection, a vacuum aspirator (10 <not shown>) is added, connected in parallel with the quick exhaust port 7, the zero point 8, the differential pressure air port 9, etc., and a vacuum solenoid valve with ultra-high sealing performance is used to control the connection and disconnection of the vacuum aspirator, so as to realize the construction and maintenance of the negative pressure environment inside the container;

[0062] The vacuum aspirator adopts a vacuum pump or a vacuum generator, etc., to establish and maintain the required negative pressure environment in the pipeline behind the tested product 1 and inside the pure water container 2;

[0063] The leak detection process is as follows:

[0064] First, open all the solenoid valves and start the vacuum aspirator to form a vacuum inside the test container (product) and the standard container (or pure water container) and maintain a certain negative pressure state. Then close the solenoid valve. At this time, the differential pressure gauge displays zero differential pressure and starts timing. If there is a leak in the test container (product), the internal pressure gradually rises as the bubbles overflow, forming a pressure difference with the standard container. The pressure difference is monitored and recorded in real time by a sensitive differential pressure gauge. The computer data acquisition and processing system receives the data from the differential pressure gauge, draws curves and performs data analysis to determine the leakage situation, outputs the test results or alarm signals, and performs corresponding processing on the tested product according to the test results.

[0065] Furthermore, a temperature sensor is added and installed near or inside the tested product 1 and the pure water container 2 to monitor and record the change of the ambient temperature during the test process to correct the influence of temperature on the pressure measurement;

[0066] The computer data acquisition and processing system is connected to the differential pressure gauge and the temperature sensor, and is used to receive and process the test data, perform data analysis and judgment through a preset algorithm, determine the leakage of the tested product (1), and output the test result or alarm signal.

[0067] Further, one or more brackets or fixtures for fixing and supporting the tested product 1 and the pure water container 2 to ensure the stability of the container during the test process;

[0068] Among them, a calibration device, including a standard leak, is used to calibrate the system before testing to ensure that the measurement accuracy of the differential pressure gauge and the detection capability of the system meet the preset standards.

[0069] Furthermore, the tested product 1 and the pure water container 2 are placed under the same environmental conditions for testing to reduce the influence of external environmental factors (such as temperature, atmospheric pressure, etc.) on the test results;

[0070] The system also includes one or more safety valves, such as an exhaust solenoid valve 3, which is installed behind the tested product 1 and the pure water container 2, and is used to automatically release pressure when overpressure occurs during the detection process to ensure the safety of the system, especially to protect the precision differential pressure sensor 6 and prevent overpressure damage.

[0071] Further, the leak detection system comprises the following steps:

[0072] The vacuum solenoid valves (SV1, SV2 and SV3) are opened, the vacuum extractor 10 is started, and the tested product 1 and the pure water container 2 are vacuumized until a preset negative pressure value is reached;

[0073] Among them, the vacuum solenoid valves (SV1, SV2 and SV3) are closed, and the differential pressure sensor 6, i.e., the differential pressure gauge, starts to monitor and record the pressure difference inside and outside the tested product 1 in real time;

[0074] Among them, start timing and record the pressure difference change data during the detection time;

[0075] Among them, the computer data acquisition and processing system receives data from the differential pressure gauge and temperature sensor, performs data analysis and judgment, determines the leakage situation of the tested product 1 according to the preset leakage judgment standard, outputs the detection result or alarm signal, and performs corresponding processing on the tested product 1 according to the detection result.

[0076] Furthermore, the method further comprises the following steps:

[0077] Wherein, the system is calibrated using a calibration device before each test to ensure that the measurement accuracy of the differential pressure sensor 6, i.e., the differential pressure gauge, and the detection capability of the system meet the preset standards;

[0078] In the detection process, the ambient temperature change is monitored in real time, and the measurement result of the differential pressure sensor 6, i.e., the differential pressure gauge, is corrected according to the data of the temperature sensor;

[0079] Among them, the computer self-check and alarm processing include the connection air tightness and working status of the differential pressure gauge, pure water container, test container, vacuum solenoid valve, vacuum aspirator, etc.;

[0080] Among them, the leak detection method of the leak detection system includes the steps of establishing a pressure difference environment, real-time monitoring of pressure difference changes, data analysis and judgment, etc., to improve the accuracy and efficiency of leak detection.

[0081] Furthermore, the leak detection system can eliminate the bubble observation window 2 of the pure water container, and the pipeline is directly connected to improve the portability of the system;

[0082] Among them, in this method, the pipeline acts as a container, and the smaller the container volume, the higher the sensitivity and the higher the resolution;

[0083] Among them, its volume size can be changed under a certain volume by testing a bubble, and the differential pressure sensor can be calibrated by using a standard leak to calibrate the change in the negative pressure value of a bubble.

[0084] Furthermore, the workshop air interface 0 is connected to a 0-30Mpa charging pipeline to meet the requirements of the tested product 1;

[0085] The leakage rate of the tested product 1 is determined by Q = △P / △T*V, where Q is the total leakage rate of the container; V is the volume of the tested product; △P is the pressure change value; △T is the detection time. It is usually carried out according to the general leakage curve B. If there is a large leakage, it is handled according to the alarm of the large leakage curve A, such as Figure 2 As shown;

[0086] Among them, △P—pressure change value is generally between 0 and 1000Pa, and △T—detection time is generally determined according to the specific test product requirements, such as 3 minutes.

[0087] Furthermore, a method for verifying an airtight leak detection system includes the following steps:

[0088] S1: Establish a reference pressure environment: First, use a vacuum solenoid valve and a vacuum extractor (such as a vacuum pump) to evacuate the inside of the tested product (test container) and a known leak-free standard container (pure water container) to a certain negative pressure state. This is done to ensure that the internal pressures of the two containers are at a known and as close to a reference level as possible before the test begins.

[0089] S2: Pressure balance and monitoring: After the vacuum is completed, the solenoid valve is closed. At this time, a certain negative pressure should be maintained inside the two containers, and theoretically the pressures of the two should be equal (or very close), so the differential pressure gauge will display zero (or a very small deviation, depending on the accuracy of the differential pressure gauge). Next, the system enters the monitoring stage, and the differential pressure gauge begins to monitor the pressure difference between the two containers in real time.

[0090] S3: Leak detection: If there is a leak in the product (container) being tested, then over time, external gases (such as air) will gradually penetrate into the interior of the container, causing the internal pressure to gradually rise. Since the standard container (or pure water container) is sealed, its internal pressure remains basically unchanged, so a pressure difference will be generated between the inside and outside of the system. This pressure difference will be captured and recorded by the sensitive differential pressure gauge.

[0091] S4: Data analysis and judgment: The computer data acquisition and processing system receives the data from the differential pressure gauge, processes and analyzes it, and by comparing the changes in the pressure difference during the test, the system can determine whether there is a leak in the tested container and the severity of the leak. In some cases, the system can also automatically issue an alarm or stop testing based on the preset threshold.

[0092] S5: Calibration and verification: In order to ensure the accuracy and reliability of the leak detection system, it is usually necessary to calibrate the system using a standard leak hole. By measuring the change in the pressure difference output by the system under specific conditions (such as known leak rate, detection time, etc.), it can be verified whether the detection capability of the system meets the requirements;

[0093] Whether it meets the requirements depends on the specific test product requirements. For example, if there are less than 3 bubbles within 3 minutes, it is qualified. The system standard volume (fixed tube length) is taken and the pressure increase is about 300Pa. Otherwise, it is considered unqualified.

[0094] S6: The principle of the automatic static differential pressure boost leak detection system is to detect leakage by monitoring the pressure difference between the container under test and the standard container. This method has the advantages of high degree of automation, high accuracy, and strong data traceability. It is widely used in situations where high-precision leak detection is required.

[0095] The above method steps can make the environment adaptable during verification strong, and by maintaining the two containers under the same environmental conditions for testing, the influence of external factors such as temperature changes on the test results is effectively reduced.

[0096] Working principle:

[0097] S1: Establish a reference pressure environment: First, use a vacuum solenoid valve and a vacuum extractor (such as a vacuum pump) to evacuate the inside of the tested product 1 (the container under test) and a known leak-free standard container (pure water container) to a certain negative pressure state. This is done to ensure that the internal pressures of the two containers are at a known and as close to a reference level as possible before the test begins.

[0098] S2: Pressure balance and monitoring: After the vacuum is completed, the solenoid valve is closed. At this time, a certain negative pressure should be maintained inside the two containers, and theoretically the pressures of the two should be equal (or very close), so the differential pressure gauge will display zero (or a very small deviation, depending on the accuracy of the differential pressure gauge). Next, the system enters the monitoring stage, and the differential pressure gauge begins to monitor the pressure difference between the two containers in real time.

[0099] S3: Leak detection: If there is a leak in the product 1 (container) under test, then over time, external gases (such as air) will gradually penetrate into the container, causing the internal pressure to gradually rise. Since the standard container (or pure water container) is sealed, its internal pressure remains basically unchanged, so a pressure difference will be generated between the inside and outside of the system. This pressure difference will be captured and recorded by the sensitive differential pressure gauge.

[0100] S4: Data analysis and judgment: The computer data acquisition and processing system receives the data from the differential pressure gauge, and processes and analyzes it. By comparing the changes in the pressure difference during the detection process, the system can determine whether there is a leak in the container 1 being tested, and the severity of the leak. In some cases, the system can also automatically issue an alarm or stop detection according to a preset threshold.

[0101] S5: Calibration and verification: In order to ensure the accuracy and reliability of the leak detection system, it is usually necessary to calibrate the system using a standard leak. By measuring the change in the pressure difference output by the system under specific conditions (such as known leakage rate, detection time, etc.), it can be verified whether the system's detection capability meets the requirements.

[0102] S6: The principle of the automatic static differential pressure boost leak detection system is to detect leakage by monitoring the pressure difference between the container under test 1 and the standard container. This method has the advantages of high automation, high accuracy, and strong data traceability. It is widely used in situations where high-precision leak detection is required.

[0103] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. An airtight leak detection system, characterized in that: include: The device comprises a workshop air interface (0), a product to be tested (1), a bubble observation window (2), an exhaust solenoid valve (3), an isolation solenoid valve (4), a zeroing solenoid valve (5), a differential pressure sensor (6), a quick exhaust port (7), a zeroing point (8) and a differential pressure to air port (9); Wherein, at least one of the tested products (1) is connected to the gas of the workshop air interface (0), and the interface is designed according to the specific testing requirements of the product structure, material, thickness and shape; wherein a bubble observation window (2) containing a pure water container, whose volume, material, thickness, shape, pipe length and internal structure all match those of the product under test (1); The pipeline behind the tested product (1) is inserted into water in a pure water container (2) having a bubble observation window; Among them, the three solenoid valves (SV1, SV2 and SV3) are respectively an exhaust solenoid valve (3), an isolation solenoid valve (4) and a zeroing solenoid valve (5). The exhaust solenoid valve (3) is used for opening and closing the rapid exhaust and is connected to the rapid exhaust port (7). The isolation solenoid valve (4) controls the tested product (1) to pass through the pure water container (2). If bubbles escape, the isolation solenoid valve (4) is connected to and disconnected from the differential pressure sensor (6) and is connected to the differential pressure air port (9). The zeroing solenoid valve (5) sets and clears the pressure difference and is connected to the zeroing point (8). Among them, a sensitive differential pressure sensor (6) whose measurement accuracy meets the detection requirements is used to monitor and record in real time whether the tested product (1) leaks and causes pressure differences inside and outside the system.

2. The airtight leak detection system according to claim 1, characterized in that: In order to improve the high-precision sensitivity of the detection, a vacuum aspirator (not shown) is added in parallel with the quick exhaust port (7), the zero point (8), and the differential pressure air port (9), and a vacuum solenoid valve with ultra-high sealing performance is used to control the connection and disconnection of the vacuum aspirator to achieve the construction and maintenance of the negative pressure environment inside the container; The vacuum extractor adopts a vacuum pump or a vacuum generator, which is used to establish and maintain the required negative pressure environment in the pipeline behind the tested product (1) and inside the pure water container (2).

3. The airtight leak detection system according to claim 1, characterized in that: Add a temperature sensor, installed near or inside the tested product (1) and the pure water container (2), to monitor and record the change of ambient temperature during the test process, so as to correct the influence of temperature on pressure measurement; Among them, the computer data acquisition and processing system is connected to the differential pressure gauge and temperature sensor.

4. The airtight leak detection system and verification method thereof according to claim 1, characterized in that: One or more brackets or fixtures for fixing and supporting the product to be tested (1) and the pure water container (2) to ensure the stability of the container during the test process; Among them, a calibration device, including a standard leak, is used to calibrate the system before testing to ensure that the measurement accuracy of the differential pressure gauge and the detection capability of the system meet the preset standards.

5. The airtight leak detection system according to claim 1, characterized in that: The tested product (1) and the pure water container (2) are placed under the same environmental conditions for testing, so as to reduce the influence of external environmental factors (such as temperature and atmospheric pressure) on the test results; The system further includes one or more safety valves, such as an exhaust solenoid valve (3), which are installed behind the tested product (1) and the pure water container (2) to automatically release pressure when overpressure occurs during the detection process, thereby ensuring the safety of the system, especially protecting the precision differential pressure sensor (6) from damage due to overpressure.

6. The airtight leak detection system according to claim 1, characterized in that: Open the vacuum solenoid valves (SV1, SV2 and SV3), start the vacuum suction device (10), and perform vacuum treatment on the tested product (1) and the pure water container (2) until a preset negative pressure value is reached; When the vacuum solenoid valves (SV1, SV2 and SV3) are closed, the differential pressure sensor (6), i.e., the differential pressure gauge, starts to monitor and record the pressure difference between the inside and outside of the tested product (1) in real time; Among them, start timing and record the pressure difference change data during the detection time; The computer data acquisition and processing system receives data from the differential pressure gauge and the temperature sensor, performs data analysis and judgment, determines the leakage of the tested product (1) according to a preset leakage judgment standard, outputs the test result or alarm signal, and performs corresponding processing on the tested product (1) according to the test result.

7. The airtight leak detection system according to claim 1, characterized in that: Before each test, the system is calibrated using a calibration device to ensure that the measurement accuracy of the differential pressure sensor (6), i.e., the differential pressure gauge, and the detection capability of the system meet the preset standards; In the detection process, the change of the ambient temperature is monitored in real time, and the measurement result of the differential pressure sensor (6), i.e., the differential pressure gauge, is corrected according to the data of the temperature sensor; Among them, the computer self-check and alarm processing include the connection air tightness and working status of the differential pressure gauge, pure water container, test container, vacuum solenoid valve and vacuum aspirator; Among them, the leak detection method of the leak detection system includes establishing a pressure difference environment, real-time monitoring of pressure difference changes, data analysis and judgment steps, so as to improve the accuracy and efficiency of leak detection.

8. The airtight leak detection system according to claim 1, characterized in that: The bubble observation window (2) of the pure water container can be removed, and the pipelines can be directly connected, thereby improving the portability of the system; Among them, in this method, the pipeline acts as a container, and the smaller the container volume, the higher the sensitivity and the higher the resolution; Among them, its volume size can be changed under a certain volume by testing a bubble, and the differential pressure sensor can be calibrated by using a standard leak to calibrate the change in the negative pressure value of a bubble.

9. The airtight leak detection system and verification method thereof according to claim 1, characterized in that: The workshop air interface (0) is connected to a 0-30Mpa pressurized pipeline to meet the requirements of the tested product (1); The leakage rate of the tested product (1) is determined by Q = △P / △T*V, where Q is the total leakage rate of the container; V is the volume of the tested product; △P is the pressure change value; △T is the detection time, which is usually carried out according to the general leakage curve B. If there is a large leakage, it is handled according to the alarm of the large leakage curve A; Among them, △P—pressure change value is generally between 0 and 1000Pa, and △T—detection time is generally determined according to the specific test product requirements, such as 3 minutes.

10. A method for verifying an airtight leak detection system, comprising the following steps: S1: Establish a reference pressure environment: First, use a vacuum solenoid valve and a vacuum extractor (such as a vacuum pump) to evacuate the inside of the tested product (test container) and a known leak-free standard container (pure water container) to a certain negative pressure state. This is done to ensure that the internal pressures of the two containers are at a known and as close to a reference level as possible before the test begins. S2: Pressure balance and monitoring: After the vacuum is completed, the solenoid valve is closed. At this time, a certain negative pressure should be maintained inside the two containers, and theoretically the pressures of the two should be equal (or very close), so the differential pressure gauge will display zero (or a very small deviation, depending on the accuracy of the differential pressure gauge). Next, the system enters the monitoring stage, and the differential pressure gauge begins to monitor the pressure difference between the two containers in real time. S3: Leak detection: If there is a leak in the product (container) being tested, then over time, external gases (such as air) will gradually penetrate into the interior of the container, causing the internal pressure to gradually rise. Since the standard container (or pure water container) is sealed, its internal pressure remains basically unchanged, so a pressure difference will be generated between the inside and outside of the system. This pressure difference will be captured and recorded by the sensitive differential pressure gauge. S4: Data analysis and judgment: The computer data acquisition and processing system receives the data from the differential pressure gauge, processes and analyzes it, and by comparing the changes in the pressure difference during the test, the system can determine whether there is a leak in the tested container and the severity of the leak. In some cases, the system can also automatically issue an alarm or stop testing based on the preset threshold. S5: Calibration and verification: In order to ensure the accuracy and reliability of the leak detection system, it is usually necessary to calibrate the system using a standard leak hole. By measuring the change in the pressure difference output by the system under specific conditions (such as known leak rate and detection time), it can be verified whether the detection capability of the system meets the requirements; Whether it meets the requirements depends on the specific test product requirements. For example, if there are less than 3 bubbles within 3 minutes, it is qualified. The system standard volume (fixed tube length) is taken and the pressure increase is about 300Pa. Otherwise, it is considered unqualified. S6: The principle of the automatic static differential pressure boost leak detection system is to detect leaks by monitoring the pressure difference between the container being tested and the standard container. This method has the advantages of high automation, high accuracy, and strong data traceability, and is widely used in situations where high-precision leak detection is required.

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