A metal seal ring leakage measuring device and measuring method

Abstract

The present application belongs to the technical field of aero-engine, and particularly relates to a metal sealing ring leakage measuring device and a measuring method. The measuring device comprises a pressure air source and an air inlet pipeline connected with the pressure air source. The other end of the air inlet pipeline is connected with a metal sealing ring, and the metal sealing ring is further connected with an air outlet pipeline. An electromagnetic valve, a pressure sensor, an electric regulating valve, a temperature sensor and a mass flowmeter are arranged on the air inlet pipeline. A cooler, a pressure sensor, a regulating valve, an electromagnetic valve and a mass flowmeter are arranged on the air outlet pipeline. The present application adopts differential pressure control. The differential pressure between high pressure side and low pressure side is adjusted in real time through the electric regulating valve, so that the measuring accuracy of the metal sealing ring leakage can be prevented from being affected by the back pressure on the low pressure side. The bellows seal is adopted, so that the high pressure side of the metal sealing ring can reach the required pressure for the test. In order to prevent the local temperature in the test cavity from being too high, the opening and closing of the valve is controlled during the test, so that the gas in the test cavity can keep flowing.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine technology, and specifically relates to a device and method for measuring the leakage of a metal sealing ring. Background Technology

[0002] Aero engines utilize large quantities of gases (air and hot exhaust gases, etc.) and liquids (lubricating oil, fuel oil, etc.) for their operation. These fluids require various types of seals to prevent leakage and maintain the engine's normal and efficient operation. In aero engines, the static seals used under high-temperature conditions are typically metal sealing rings such as W-type and C-type sealing rings. To accurately evaluate the sealing performance of these metal sealing rings, it is necessary to accurately measure their leakage during testing. Currently, commonly used methods for measuring gas leakage include the displacement method and the pressure balance method.

[0003] The water displacement method is currently the most commonly used method for measuring gas leakage in sealing devices. The water displacement measuring device mainly consists of a water tank, a gas collector, a venting valve, and a gas pipe. The gas collector is placed upside down in the water tank, with a connector at its bottom that connects to the gas pipe and venting valve. The gas collector is submerged in the water in the tank, and the leaking gas enters the gas collector through the gas pipe. Since the leaking gas from the sealing device is insoluble in water, it displaces the water in the collector, raising the water level in the tank. After a certain period, a level difference naturally forms between the initial and current levels. The volume of gas in the gas collector is calculated based on this level difference. This measured gas volume is then converted into air mass, which represents the amount of gas leakage from the sealing device over a certain period. However, because this method converts the gas leakage amount from the water displacement volume, and volume is temperature-dependent, the water displacement method is more suitable for measuring the air leakage of dynamic seals at normal temperatures. Its accuracy is poor under high or low temperature conditions.

[0004] The pressure balancing method for measuring gas leakage in a sealing device requires a dedicated measurement adapter. The sealing device is installed between two chambers, A and B. Chamber A is a low-pressure chamber open to the atmosphere, while chamber B is a high-pressure chamber. Gas leaks from the high-pressure chamber into chamber A through a dynamic seal. During measurement, chamber B is first filled with high-temperature, high-pressure air, and the intake volume and temperature are adjusted to meet the test requirements. With the gas pressure and temperature in chamber B remaining constant, a mass flow meter is used to measure the intake volume in chamber B. The total intake volume measured over a certain period equals the total leakage of the sealing metal ring during that period. The total leakage volume divided by the time equals the leakage per unit time. However, because the air pressure in chamber B is greater than that in chamber A, it will generate a certain axial force on the shaft. Therefore, the pressure balancing method is suitable for operating conditions where the pressure difference between chambers A and B is small (i.e., a small pressure difference across the sealing components). The measurement accuracy of the pressure balancing method depends on the control accuracy of the pressure in the high-pressure chamber (chamber B) and the accuracy of the mass flow meter. Furthermore, when there is a large back pressure in the low-pressure chamber (chamber A), this method will be inaccurate.

[0005] A patent with publication number CN105864148A discloses a quantitative measurement device and method for measuring the leakage of sealing rings in hydraulic cylinders. The device mainly includes a cylinder body, piston rod, piston sleeve, end caps, and sealing rings. The piston rod is bolted to the piston sleeve and placed inside the cylinder body. Three detection oil passages are opened on the piston sleeve leading to the piston rod, and each detection oil passage is connected to a hose and a measuring cylinder. Four sealing rings are provided on the outer wall of the piston sleeve. End caps are installed at both ends of the cylinder body, and dustproof rings, O-rings A, guide rings A and B, and sealing rings are sequentially installed in the mounting holes of the end caps. Detection oil passages are opened from the top of the cylinder body downwards through the end caps, and a measuring cylinder is connected above the detection oil passages. The piston rod extends from both ends of the piston rod through the end caps. Oil ports A and B are symmetrically opened on the top of the cylinder body. The method of forming the leakage through the cooperation of the piston rod and piston sleeve in this patent is not intuitive and the setup is relatively complex.

[0006] Therefore, there is a need to propose a device for measuring the gas leakage of metal sealing rings in aero-engines that has a wide range of applications and high measurement accuracy. Summary of the Invention

[0007] To address the aforementioned problems, this invention proposes a metal sealing ring leakage measurement device, comprising a pressurized air source and an air inlet pipe connected to the pressurized air source, the other end of the air inlet pipe being connected to the metal sealing ring, and the metal sealing ring also being connected to an air outlet pipe.

[0008] The intake pipe is equipped with a solenoid valve, a pressure sensor, an electric regulating valve, a temperature sensor, and a mass flow meter;

[0009] The outlet pipe is equipped with a cooler, a pressure sensor, a regulating valve, a solenoid valve, and a mass flow meter.

[0010] Furthermore, the intake pipeline includes a main air supply pipeline connected to a compressed air source and a first pipeline and a second pipeline connected to the other end of the main air supply pipeline, wherein the first pipeline and the second pipeline are connected in parallel.

[0011] The other end of the first pipeline is connected to the air inlet A opened in the inner cavity of the metal sealing ring;

[0012] The other end of the second pipeline is connected to the B air inlet in the outer cavity of the metal sealing ring.

[0013] Furthermore, the air outlet pipeline includes a third pipeline connected to the C-shaped air outlet opening in the inner cavity of the metal sealing ring;

[0014] And a fourth pipeline connected to the D-outlet opening in the outer cavity of the metal sealing ring;

[0015] The other ends of the third and fourth pipes are connected to the cooler.

[0016] Furthermore, an electric regulating valve, a temperature sensor, a solenoid valve, and a pressure sensor are installed on the first pipeline;

[0017] The second pipeline is equipped with an electric regulating valve, a mass flow meter, a temperature sensor, a solenoid valve, and a pressure sensor;

[0018] Solenoid valves, pressure sensors, and temperature sensors are installed on the main gas pipeline.

[0019] Furthermore, a pressure sensor, a temperature sensor, a regulating valve, and a solenoid valve are installed on the third pipeline;

[0020] The fourth pipeline is equipped with a pressure sensor, a temperature sensor, a regulating valve, a mass flow meter, and solenoid valves on both sides of the mass flow meter.

[0021] Furthermore, an upper pressure plate is provided above the metal sealing ring, and a lower pressure plate is provided below it;

[0022] A bellows seal is installed between the upper and lower pressure plates.

[0023] On the other hand, the present invention proposes a method for measuring the leakage of a metal sealing ring, comprising the following steps:

[0024] Determine the opening type of the metal sealing ring and identify the inner and outer cavities of the metal sealing ring;

[0025] The measurement scheme of the measuring device is determined according to the type of opening, including opening the corresponding solenoid valve, pressure sensor, electric regulating valve, temperature sensor, mass flow meter and regulating valve;

[0026] The leakage of the metal sealing ring is measured according to the aforementioned measurement scheme.

[0027] Furthermore, when the metal sealing ring is an internally open metal sealing ring, the inner cavity of the metal sealing ring is the high-pressure side, and the outer cavity is the low-pressure side. The measurement method is specifically as follows:

[0028] Open the solenoid valves on the main gas pipeline, the second pipeline, and the fourth pipeline. Gas enters the inner cavity of the metal sealing ring through the B inlet and exits through the C outlet.

[0029] Adjust the electric regulating valves on the first and second pipelines to keep the gas pressure difference between the inner and outer cavities of the metal sealing ring constant within the measurement range;

[0030] Open the solenoid valve on the fourth pipeline, and the gas in the outer cavity will exit from the D outlet. Turn on the cooler to cool the gas exiting from the D outlet.

[0031] The cooled gas enters the mass flow meter on the fourth pipeline;

[0032] The leakage is measured using a direct measurement method, and the air intake of the mass flow meter on the fourth pipeline is the leakage of the metal sealing ring.

[0033] Furthermore, when the metal sealing ring is an internally open metal sealing ring, the leakage is measured using the differential measurement method, specifically as follows:

[0034] When the cooled gas enters the mass flow meter on the fourth pipeline;

[0035] The difference between the air intake volume of the mass flow meter on the fourth pipeline and the air intake volume of the mass flow meter on the second pipeline is the leakage of the metal sealing ring.

[0036] Furthermore, when the metal sealing ring has an external opening, the outer cavity of the metal sealing ring is the high-pressure side, and the inner cavity of the metal sealing ring is the low-pressure side. The measurement method is specifically as follows:

[0037] Open the solenoid valves on the main gas pipeline, the first pipeline, and the fourth pipeline. Gas enters the outer cavity of the metal sealing ring through the inlet A and exits through the outlet D.

[0038] The gas pressure in the outer cavity of the metal sealing ring is adjusted by the electric regulating valve on the first pipeline to keep the pressure difference between the outer and inner cavities constant within the measurement range. The gas output from the outer cavity is adjusted by the regulating valve on the fourth pipeline to allow the gas to flow in the outer cavity.

[0039] The gas leaking from the metal sealing ring is discharged through outlet C and cooled by the cooler. The amount of gas entering the pipe, measured by the mass flow meter on the fourth pipeline, is the leakage amount from the metal sealing ring.

[0040] The beneficial effects of this invention are:

[0041] To avoid excessively high local temperatures during gas heating, this invention controls the opening and closing of corresponding valves to allow a certain flow of gas to enter the outer cavity, thus maintaining airflow within the cavity.

[0042] The metal sealing ring leakage measurement device of this invention adopts differential pressure control, that is, it simultaneously measures the gas pressure on the high-pressure side and the low-pressure side, and adjusts the pressure difference between the high and low pressure sides in real time through an electric regulating valve to accurately control the pressure difference of the metal sealing ring; it prevents back pressure on the low-pressure side from affecting the measurement accuracy of the metal sealing ring leakage; and it uses a bellows seal for sealing between the upper and lower pressure plates, which facilitates the high-pressure side of the metal sealing ring to reach the pressure required for the test; in order to prevent the local temperature in the test chamber from being too high, the opening and closing of the valve is controlled during the test to ensure that the gas in the test chamber remains flowing.

[0043] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 A schematic diagram of the metal sealing ring leakage measurement device in an embodiment of the present invention is shown;

[0046] Figure 2 A schematic diagram of an internally opening metal sealing ring in an embodiment of the present invention is shown;

[0047] Figure 3 A schematic diagram of an externally opening metal sealing ring in an embodiment of the present invention is shown;

[0048] Figure 4 A schematic diagram of the method for measuring leakage of the internally opened metal sealing ring in an embodiment of the present invention is shown;

[0049] Figure 5 A schematic diagram of the leakage measurement method of the external opening metal sealing ring in an embodiment of the present invention is shown;

[0050] In the diagram: 1. First solenoid valve; 2. First electric regulating valve; 3. Second electric regulating valve; 4. Second solenoid valve; 5. Third solenoid valve; 6. First regulating valve; 7. Fourth solenoid valve; 8. Fifth solenoid valve; 9. Second regulating valve; 10. Sixth solenoid valve; 11. Pressurized air source; 12. Cooler; 13. Lower pressure plate; 14. Metal sealing ring; 15. Bellows seal; 16. Upper pressure plate; 17. First mass flow meter; 18. Second mass flow meter. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] The purpose of this invention is to provide a device and method for measuring gas leakage in the metal sealing ring of an aero-engine, solving the problems of large measurement errors and inaccurate measurements under back pressure in current leakage measurement devices. The metal sealing ring leakage measurement device of this invention consists of a pressurized air source 11, a solenoid valve, a regulating valve, an electric regulating valve, a mass flow meter, a cooler 12, a temperature sensor, and a pressure sensor.

[0053] in,

[0054] Pressurized air source 11 is used to provide the pressurized air required for the test;

[0055] Multiple solenoid valves are installed to control the opening and closing of pipelines. By controlling the opening of the corresponding solenoid valve, a certain flow of gas enters the outer cavity, keeping the air in the inner cavity flowing.

[0056] Multiple regulating valves are provided to regulate the flow rate of gas in the pipeline;

[0057] The electric regulating valve is equipped with multiple valves for automatically regulating the air pressure in the pipeline, adjusting the pressure difference between the high and low pressure sides of the metal sealing ring 14 in real time, and precisely controlling the pressure difference of the metal sealing ring 14.

[0058] Mass flow meters are used to measure the flow rate in pipelines;

[0059] Cooler 12 is used to cool the hot air to below 200°C;

[0060] Temperature sensors are used for measuring the temperature of gases;

[0061] Pressure sensors are used to measure the pressure of gases.

[0062] This embodiment uses a metal W-shaped sealing ring as an example to illustrate the structure of the measuring device. The W-shaped sealing ring possesses excellent axial compressibility, suitable stiffness, good resilience, and vibration adaptability, and is widely used in the latest generation of aero-engines. Reducing sealing leakage will increase engine thrust and reduce fuel consumption. However, the metal W-shaped sealing ring operates under harsh conditions, frequently facing high temperature, high pressure, and highly corrosive environments. Therefore, accurately measuring its leakage is particularly important for improving the overall performance of the engine.

[0063] This embodiment uses Figure 1 Taking the illustrated measuring device as an example, the measuring device includes a metal sealing ring 14, with an upper pressure plate 16 above the metal sealing ring 14 and a lower pressure plate 13 below it. The upper pressure plate 16 is driven by a metal sealing ring loading device to simulate the axial load and actual compression of the metal sealing ring 14. A bellows seal 15 is installed between the upper pressure plate 16 and the lower pressure plate 13, which seals the area between them, facilitating the high-pressure side of the metal sealing ring 14 to reach the pressure required for the test. The portion between the metal sealing ring 14 and the bellows seal 15 is the outer cavity, and the interior of the metal sealing ring 14 is the inner cavity. Gas pipeline interfaces are respectively installed in the inner and outer cavities according to the actual measurement requirements.

[0064] The interface includes an air inlet and an air outlet. In this embodiment, multiple air inlets (B and C) are provided in the inner cavity, and air inlets (A and D) are provided in the outer cavity. Gas enters the inner cavity of the metal sealing ring through air inlets (B) and exits through air outlets (C), forming a passage in the inner cavity of the metal sealing ring 14. Gas also enters the outer cavity of the metal sealing ring 14 through air inlets (A) and exits through air outlets (D), forming a passage in the outer cavity of the metal sealing ring 14. The other ends of the pipes connected to air inlets A and B are both connected to the gas supply pipes of the pressurized air source 11, which provides the pressurized air required for the test. For ease of description, the outlet pipe of the pressurized air source 11 is referred to as the gas supply pipe, the pipe connecting air inlet A and the gas supply pipe is referred to as the first pipe, and the pipe between air inlet B and the gas supply pipe is referred to as the second pipe. The first and second pipes are arranged in parallel, leading out from air inlets A and B respectively and then connecting to the gas supply pipes of the pressurized air source 11. On the first pipeline, from the air inlet A towards the compressed air source 11, a pressure sensor, a second solenoid valve 4, a temperature sensor, and a first electric regulating valve 2 are installed in sequence; on the second pipeline, from the air inlet B towards the compressed air source 11, a pressure sensor, a third solenoid valve 5, a temperature sensor, a first mass flow meter 17, and a second electric regulating valve 3 are installed in sequence. Figure 1 The dashed line between the electric regulating valve and the pressure sensor indicates closed-loop control, which allows the pipeline pressure to be controlled remotely via the electric regulating valve.

[0065] The present invention also adds a cooler 12 to the gas output pipelines of the inner and outer cavities (i.e., the third and fourth pipelines in this embodiment), which can cool the high-temperature gas to a low temperature below 200°C, facilitating the measurement of the pressure and temperature of the leaked gas. The other end of the pipeline connecting the C and D outlets is connected to the cooler 12. The pipelines leading out from the cooler 12 are the third pipeline (extending from the C outlet) and the fourth pipeline (extending from the D outlet). On the fourth pipeline, a pressure sensor, a temperature sensor, a first regulating valve 6, a fourth solenoid valve 7, a second mass flow meter 18, and a fifth solenoid valve 8 are arranged sequentially outward from the direction closest to the cooler 12. On the third pipeline, a pressure sensor, a temperature sensor, a second regulating valve 9, and a sixth solenoid valve 10 are arranged sequentially outward from the direction closest to the cooler 12.

[0066] It should be noted that the design of the measuring device of the present invention is not limited to... Figure 1 In the structure shown, the positions of the pressure and temperature sensors on the gas supply line, the third line, and the fourth line are not strictly limited in this embodiment, as long as they can detect the temperature and pressure of the gas. Solenoid valves should be installed on both sides of the mass flow meter to quickly control the gas entering the mass flow meter. In one embodiment of the invention, the second mass flow meter 18 is installed on the third line. The invention also includes a heating device for the metal sealing ring 14, used to heat the metal sealing ring 14, the upper pressure plate 16, and the lower pressure plate 13 to the temperature required for the test.

[0067] Metal sealing rings 14 generally include externally open metal sealing rings and internally open metal sealing rings. The structures of internally open metal W-shaped sealing rings and externally open metal W-shaped sealing rings are as follows: Figure 2 and Figure 3 As shown, all openings face the high-pressure side. Different measurement schemes can be selected to measure the leakage of the metal sealing ring 14 based on the opening orientation. The measurement schemes generally include the difference method and the direct measurement method. The measurement methods are explained below using metal sealing rings 14 with different opening orientations.

[0068] In one embodiment of the present invention, when the metal sealing ring 14 is an internally open metal sealing ring, such as Figure 4As shown, the inner cavity is the high-pressure side, and the outer cavity is the low-pressure side. The gas flow path in this embodiment is shown by the thick black solid line in the figure: Opening the first solenoid valve 1, the third solenoid valve 5, the fourth solenoid valve 7, and the fifth solenoid valve 8 allows gas to enter the inner cavity through inlet B and exit through outlet C, forming a passage within the inner cavity. The gas pressure in the inner cavity is adjusted by the second electric regulating valve 3. To prevent excessively high local temperatures during gas heating, the first electric regulating valve 2 adjusts the flow to allow a small flow rate and pressure of gas to enter the outer cavity, forming a gas flow path and enabling gas flow. The gas in the outer cavity exits through outlet D, is cooled to a low temperature by the cooler 12, and then discharged to the atmosphere through the first regulating valve 6. The first regulating valve 6 can adjust the gas flow rate. Leakage can be measured using either a direct measurement method or a differential measurement method. In one embodiment of the invention, a direct measurement method is used. When the pressure difference between the inner and outer cavities remains constant, the inlet volume of the first mass flow meter 17 is the leakage volume of the metal sealing ring 14. In another embodiment of the invention, the leakage is measured using a differential measurement method. Simultaneously, the gas flow rates of the first mass flow meter 17 and the second mass flow meter 18 are measured. The gas in the inner cavity exits from outlet C. The fourth solenoid valve 7 and the fifth solenoid valve 8 are opened. After the gas temperature is reduced to below 200°C by the cooler 12, it passes through the second mass flow meter 18 and is then discharged into the atmosphere. The pressure in the inner cavity is adjusted by the second electric regulating valve 3 to ensure the required pressure difference between the inner and outer cavities for the test. The difference between the first mass flow meter 17 and the second mass flow meter 18 represents the leakage of the metal sealing ring 14. In another embodiment of the invention, the gas flow path can be as shown by the light-colored dashed line in the figure.

[0069] In one embodiment of the present invention, when the metal sealing ring 14 is an externally open metal sealing ring, such as Figure 5 As shown, the outer cavity is the high-pressure side, and the inner cavity is the low-pressure side. A schematic diagram of the gas flow path is shown below. Figure 5 The diagram shows the gas flow. To prevent excessively high local temperatures during gas heating, the first solenoid valve 1, the second solenoid valve 4, the fourth solenoid valve 7, the fifth solenoid valve 8, and the second regulating valve 9 are opened. Gas enters the outer cavity through inlet A and exits through outlet D, forming a passage in the outer cavity. Gas leaking from the metal sealing ring 14 is discharged through outlet C. After being cooled to a low temperature by cooler 12, gas pressure and temperature are measured. The gas flow rate in the pipeline is then measured by the second mass flow meter 18 and discharged to the atmosphere through the fifth solenoid valve 8. The gas pressure in the outer cavity is adjusted by the first electric regulating valve 2 to achieve the pressure difference between the outer and inner cavities required for the test. The gas flow rate in the outer cavity is adjusted by the first regulating valve 6 to ensure gas flow. The leakage can be measured directly: the third solenoid valve 5 is closed, and the leakage at outlet C is directly measured. The gas flow rate is measured by the second mass flow meter 18, and the inlet volume measured by the second mass flow meter 18 is the leakage of the metal sealing ring 14. In another embodiment of the invention, the gas flow path is shown by the bold black dashed line in the figure.

[0070] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for measuring the leakage of a metal sealing ring, characterized in that, A metal sealing ring leakage measurement device includes a pressurized air source and an air inlet pipe connected to the pressurized air source. The other end of the air inlet pipe is connected to the metal sealing ring, and the metal sealing ring is also connected to an air outlet pipe. An upper pressure plate is provided above the metal sealing ring, and a lower pressure plate is provided below it. A bellows seal is installed between the upper pressure plate and the lower pressure plate. The intake pipeline is equipped with a solenoid valve, a pressure sensor, an electric regulating valve, a temperature sensor, and a mass flow meter; the intake pipeline includes a main air supply pipeline connected to a pressurized air source and a first pipeline and a second pipeline connected to the other end of the main air supply pipeline, the first pipeline and the second pipeline being connected in parallel; The other end of the first pipeline is connected to the air inlet A opened in the outer cavity of the metal sealing ring; The exhaust pipe is equipped with a cooler, a pressure sensor, a regulating valve, a temperature sensor, a solenoid valve, and a mass flow meter; the other end of the second pipe is connected to the B inlet in the inner cavity of the metal sealing ring; the exhaust pipe includes a third pipe connected to the C outlet in the inner cavity of the metal sealing ring; and a fourth pipe connected to the D outlet in the outer cavity of the metal sealing ring; the other ends of the third and fourth pipes are connected to the cooler; An electric regulating valve, a temperature sensor, a solenoid valve, and a pressure sensor are installed on the first pipeline; The second pipeline is equipped with an electric regulating valve, a mass flow meter, a temperature sensor, a solenoid valve, and a pressure sensor; Solenoid valves, pressure sensors, and temperature sensors are installed on the main gas pipeline; A pressure sensor, a temperature sensor, a regulating valve, and a solenoid valve are installed on the third pipeline leading out from the cooler; A pressure sensor, a temperature sensor, a regulating valve, a mass flow meter, and solenoid valves on both sides of the mass flow meter are installed on the fourth pipeline leading out from the cooler. The measuring device uses differential pressure control to simultaneously measure the gas pressure on the high-pressure side and the low-pressure side. The differential pressure between the high and low pressure sides is adjusted in real time through an electric regulating valve to precisely control the differential pressure of the metal sealing ring and prevent back pressure from occurring on the low-pressure side. The method for measuring the leakage of the metal sealing ring includes the following steps: Determine the opening type of the metal sealing ring and identify the inner and outer cavities of the metal sealing ring; The measurement scheme of the measuring device is determined according to the type of opening, including opening the corresponding solenoid valve, pressure sensor, electric regulating valve, temperature sensor, mass flow meter and regulating valve; The leakage of the metal sealing ring was measured according to the aforementioned measurement scheme; When the metal sealing ring is an internally open metal sealing ring, the inner cavity of the metal sealing ring is the high-pressure side, and the outer cavity is the low-pressure side. The measurement method is as follows: Open the solenoid valves on the main gas pipeline, the second pipeline, and the fourth pipeline. Gas enters the inner cavity of the metal sealing ring through the B inlet and exits through the C outlet. Adjust the electric regulating valve on the second pipeline to keep the gas pressure difference between the inner and outer cavities of the metal sealing ring constant within the measurement range; To avoid excessively high local temperatures during gas heating, a small flow rate and pressure of gas are introduced into the outer cavity through an electric regulating valve on the first pipeline, forming a gas flow path and allowing the gas to flow. Open the solenoid valve on the fourth pipeline, and the gas in the outer cavity will exit from the D outlet. Turn on the cooler to cool the gas exiting from the D outlet. The cooled gas enters the mass flow meter on the fourth pipeline; The leakage is measured by direct measurement. When the pressure difference between the inner and outer cavities remains constant, the air intake of the mass flow meter on the second pipeline is the leakage of the metal sealing ring.

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