Detection system and detection method for detecting bidirectional leakage rate of spherical sealing valve of air entraining system of airplane

Abstract

The invention relates to the technical field of sealing performance detection, and discloses a detection system and a detection method for detecting the two-way leakage rate of a spherical sealing valve of an aircraft bleed air system. The system comprises an air inlet device, a sealing device and a detection device, the gas inlet device provides clean test gas with controllable pressure; the sealing device is used for fixing the spherical sealing valve and simulating two sealing states of the spherical sealing valve in the high-pressure stage regulator to form two independent test gas paths; the detection device is connected with an outlet of the sealing device, is used for quantitatively or qualitatively detecting leaked gas and comprises a flow monitoring unit and a pressure difference monitoring unit; the sealing device can respectively test the sealing performance of the ceramic ball and the lift valve seat and the sealing performance of the ceramic ball and the valve mounting seat by replacing or adjusting the limiting structure; according to the invention, component-level bidirectional sealing performance detection is realized, the test precision and the maintenance efficiency are improved, defects can be identified before assembly, and the rework rate is reduced.

Description

Technical Field

[0001] This invention relates to the field of sealing performance testing technology, and in particular to a testing system and method for detecting bidirectional leakage of a spherical sealing valve in an aircraft bleed air system. Background Technology

[0002] The aircraft bleed air system is one of the key subsystems of modern aero engines, primarily used to extract high-temperature, high-pressure air from the compressor to provide a stable air source for systems such as air conditioning and anti-icing. Under low-power conditions, the high-pressure stage regulator maintains stable system operation by controlling the pressure and flow rate of the bleed air from the 9th stage compressor. The spherical sealing valve, as a critical shut-off element, isolates the airflow under over-temperature and over-pressure conditions, ensuring system safety. This valve typically consists of a ceramic ball, a lift valve seat, and a valve mounting base. The ceramic ball can form a line contact sealing pair with either the lift valve seat or the valve mounting base under different pressure conditions, achieving a bidirectional sealing function.

[0003] However, existing technologies lack independent component-level sealing performance testing methods for spherical sealing valves. For example, Chinese invention patent CN209606081U provides a testing device for a high-pressure bleed air valve of an A320 aircraft engine, which can only perform overall functional testing after the bleed air valve is assembled into the high-pressure stage regulator assembly. If the test fails, repeated disassembly, troubleshooting, reassembly, and retesting are required, which is cumbersome, inefficient, and cannot identify valve defects before assembly, resulting in a high rework rate and seriously affecting maintenance efficiency and operating costs. Therefore, there is an urgent need for a dedicated testing system and method that can evaluate the sealing performance of spherical sealing valves under both low-pressure and high-pressure conditions before assembly to solve the above problems. Summary of the Invention

[0004] This application provides a detection system and method for detecting bidirectional leakage of a spherical sealing valve in an aircraft bleed air system. This can solve the technical problem that the prior art cannot perform component-level bidirectional sealing performance testing on the spherical sealing valve before assembly, resulting in low maintenance efficiency and high cost.

[0005] To solve the above problems, the present invention adopts the following technical solution: This invention provides a detection system for detecting bidirectional leakage of a spherical sealing valve in an aircraft bleed air system. The spherical sealing valve includes a ceramic ball, a lift valve seat, and a valve mounting base. During operation, the ceramic ball is selectively pressed against either the lift valve seat or the valve mounting base to form two different sealing pairs. The detection system includes: an air intake device for providing pressure-controlled and clean test gas; a sealing device connected to the air intake device for accommodating and fixing the spherical sealing valve under test, and simulating its two sealing states in the high-pressure stage regulator assembly of the aircraft bleed air system to form two independent test gas paths; and a detection device disposed on opposite sides of the gas paths of the sealing device for quantitatively detecting and / or qualitatively tracing the gas flow rate leaking from the sealing device. The detection device includes a flow monitoring unit and a differential pressure monitoring unit. The sealing device is configured to perform low-pressure sealing pair testing between the ceramic ball and the lift valve seat, and high-pressure sealing pair testing between the ceramic ball and the valve mounting base, respectively, by replacing or adjusting the internal limiting structure.

[0006] In a preferred embodiment, the differential pressure monitoring unit includes a first pressure sensor and a second pressure sensor; the first pressure sensor is disposed at the air inlet of the sealing device, and the second pressure sensor is disposed at the air outlet of the sealing device; the differential pressure monitoring unit is configured to calculate and display the real-time differential pressure inside and outside the sealing device based on the readings of the first pressure sensor and the second pressure sensor.

[0007] In a preferred embodiment, the sealing device includes: a sealing housing assembly comprising a detachably connected first housing and a second housing, the inner cavity shape of which matches the outer shape of the spherical sealing valve; at least one radial limiting block disposed in the inner cavity for radially limiting the ceramic ball; at least one axial limiting block disposed in the inner cavity for axially limiting the lift valve seat or the valve mounting seat; wherein the first housing and / or the second housing are provided with the air inlet and air outlet.

[0008] In a preferred embodiment, the flow monitoring unit is a float flow meter, and its inlet is connected to the air outlet of the sealing device via a pipeline.

[0009] In a preferred embodiment, the detection device further includes a leak-indicating medium unit, which is a transparent container filled with liquid, and the outlet pipe of the float flowmeter extends below the liquid surface of the transparent container.

[0010] In a preferred embodiment, the sealing housing assembly further includes a rubber sealing ring disposed in the sealing groove of the lift valve seat and the valve mounting seat, for achieving a static seal between the sealing housing assembly and the valve under test.

[0011] In a preferred embodiment, the air intake device includes an air source, a pressure reducing valve, and a switching valve. The air source is a high-pressure gas cylinder or an air pump, and the gas provided by the air source is compressed air or nitrogen.

[0012] The second aspect of this application provides a method for detecting bidirectional leakage of a spherical sealing valve in an aircraft bleed air system using the detection system described above, comprising the following steps: S1, Low-pressure sealing performance test: S10, the lifting valve seat and ceramic ball of the spherical sealing valve are installed into the sealing device, and the radial limiting block and axial limiting block are used to limit it; S11, connecting the air intake device and the detection device; S12, turn on the air source and adjust the inlet pressure to the specified low-pressure test pressure; S13, observe and record stable leakage values ​​and real-time differential pressure data through the detection device; S2, High-pressure sealing performance test: S20, disassemble the sealing device and remove the lift valve seat and the ceramic ball; S21, install the valve mounting base and the ceramic ball into the sealing device, and use the axial limiting block to limit them before reconnecting the pipeline; S22, turn on the gas source and adjust the inlet pressure to the specified high-pressure test pressure; S23, observe and record stable leakage values ​​and real-time differential pressure data through the detection device; S3. Compare the leakage and differential pressure data measured in steps S1 and S2 with the standard requirements to verify the bidirectional sealing performance of the spherical sealing valve.

[0013] In a preferred embodiment, steps S13 and S23 specifically include: reading the stable reading of the float flowmeter as a quantitative leakage flow value; and visually observing whether continuous bubbles are generated in the leakage indicator medium unit as a basis for qualitative leakage judgment.

[0014] In a preferred embodiment, before step S1, a self-test step S0 for the detection device seal is included: without installing the spherical sealing valve, the inner cavity of the sealing device is closed, a test pressure is introduced, and the leakage reading of the detection device is observed to see if it is within the specified range.

[0015] The technical solution adopted in this invention can achieve the following beneficial effects: This application provides a detection system and method for detecting bidirectional leakage of a spherical sealing valve in an aircraft bleed air system. By incorporating an intake device to provide controllable clean gas, and a sealing device to fix the spherical sealing valve and simulate its two sealing states in a high-pressure regulator, two independent test gas paths are formed. The test mode can be switched by replacing or adjusting the internal limiting structure. The detection device includes a flow monitoring unit and a differential pressure monitoring unit for quantitative or qualitative detection of leaking gas. This solves the problem of not being able to perform component-level bidirectional sealing performance testing on the spherical sealing valve before assembly. It enables separate testing of two key sealing pairs: the ceramic ball and the lift valve seat, and the ceramic ball and the valve mounting seat, avoiding rework after assembly. It improves the scientific rigor and reliability of the detection; allows for early defect identification in a laboratory environment, significantly improving assembly success rate and maintenance efficiency. Attached Figure Description

[0016] 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 only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic block diagram of a detection system for detecting bidirectional leakage of a spherical sealing valve in an aircraft bleed air system, as disclosed in some embodiments of this application. Figure 2 This is a cross-sectional view of the sealing device of the detection system disclosed in some embodiments of this application during the low-pressure sealing performance test stage; Figure 3 This is a cross-sectional view of the sealing device of the detection system disclosed in some embodiments of this application during the high-pressure sealing performance test stage; Figure 4 This is a flowchart of a method for detecting bidirectional leakage of a spherical sealing valve in an aircraft bleed air system, as disclosed in some embodiments of this application. Figure 5 This is a flowchart illustrating the low-pressure sealing performance test in some embodiments of the present application. Figure 6 This is a flowchart illustrating the specific process of high-pressure sealing performance testing in some embodiments of this application.

[0018] In the picture: 1. A detection system for detecting bidirectional leakage of a spherical sealing valve in an aircraft bleed air system; 10. Air intake device; 11. Sealing device; 12. Detection device; 20. Ceramic ball; 21. Lift valve seat; 22. Valve mounting base; 100. Gas source; 101. Pressure reducing valve; 102. Switch valve; 110. Inlet port; 111. Outlet port; 112. Sealing housing assembly; 113. Radial limit block; 114. Axial limit block; 115. Inner cavity; 120. Flow monitoring unit; 121. Differential pressure monitoring unit; 122. Leakage indicator unit; 1120, First housing; 1121, Second housing; 1122, Rubber sealing ring; 1210, First pressure sensor; 1211, Second pressure sensor. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0020] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0021] The aircraft bleed air system is one of the key subsystems of modern aero engines, used to extract high-temperature, high-pressure air from the engine compressor to provide a stable air supply for airborne systems such as air conditioning and anti-icing. During low-power operation, the high-pressure stage regulator maintains the normal operation of downstream systems by controlling the bleed air pressure and flow rate of the 9th stage compressor. The spherical sealing valve, as the core shut-off element in this system, functions to cut off the airflow path under specific operating conditions, preventing overheated and overpressured gases from impacting downstream components and ensuring the safe operation of the system.

[0022] During operation, this valve relies on the line contact between a ceramic ball and two different mating surfaces to form a sealing pair: under low-pressure conditions, the ceramic ball is pressed against the lift valve seat to form the first sealing pair; under high-pressure conditions, the ceramic ball is pressed against the valve mounting base to form the second sealing pair. The integrity of these two sealing pairs directly determines the stability and safety of the bleed air system. However, current technology lacks effective means for independent component-level testing of spherical sealing valves; typically, they can only be assembled into the high-pressure stage regulator assembly for overall performance testing. If the test fails, repeated disassembly and troubleshooting are required, making it difficult to determine whether the root cause of the failure stems from a defect in the valve body, resulting in long maintenance cycles, high costs, and low efficiency. Especially when there is minor wear or deformation on the ceramic ball or mating sealing surface, traditional methods cannot achieve early identification, seriously affecting the first-pass yield and operational economy.

[0023] The following is in conjunction with the appendix Figure 1 To be continued Figure 6 This paper provides a detailed description of the detection system and method for detecting bidirectional leakage of a spherical sealing valve in an aircraft bleed air system, through specific embodiments and application scenarios.

[0024] Specifically, the spherical sealing valve includes a ceramic ball 20, a lift valve seat 21, and a valve mounting seat 22. During the operation of the valve, the ceramic ball 20 is selectively pressed against the lift valve seat 21 or the valve mounting seat 22 to form two different sealing pairs.

[0025] This application provides a detection system 1 for detecting bidirectional leakage of a spherical sealing valve in an aircraft bleed air system. The system includes an air intake device 10, a sealing device 11, and a detection device 12. The detection device 12 is located on opposite sides of the air path of the sealing device 11 and includes a flow monitoring unit 120 and a differential pressure monitoring unit 121. The sealing device 11 is configured to perform low-pressure sealing tests between the ceramic ball 20 of the spherical sealing valve and the lift valve seat 21, and high-pressure sealing tests between the ceramic ball 20 and the valve mounting seat 22, respectively, by replacing or adjusting the internal limiting structure. The sealing device 11 is connected to the air intake device 10 via the differential pressure monitoring unit 121. The air intake device 10 provides pressure-controlled and clean test gas. The sealing device 11 accommodates and fixes the spherical sealing valve to be tested and simulates its two sealing states in the high-pressure stage regulator assembly of the aircraft bleed air system, forming two independent test air paths. The detection device 12 is used to quantitatively detect and / or qualitatively trace the flow rate of gas leaking from the sealing device 11.

[0026] Specifically, the overall structure of the detection system provided in this embodiment includes three main parts: an air intake device 10, a sealing device 11, and a detection device 12. It can simulate two key sealing states of the spherical sealing valve in actual use and establish independent test air paths for each. This enables separate sealing performance verification of the two sealing pairs between the ceramic ball 20 and the lift valve seat 21 inside the spherical sealing valve, and between the ceramic ball 20 and the valve mounting seat 22. It can be understood that by changing the force direction and positioning method of the ceramic ball 20 through an adjustable or replaceable limiting structure, it can form effective sealing contact with different mating surfaces at different test stages, thereby completing the independent leakage assessment under low pressure and high pressure conditions. The entire detection process can be completed in a laboratory environment without relying on the assembly of the whole machine, which significantly improves the detection efficiency and the reliability of the results.

[0027] Specifically, the air intake device 10 is used to provide pressure-controlled and clean test gas. This air intake device 10 can be used with compressed air or inert gas (such as nitrogen) as the test medium, and can optionally use a high-pressure gas cylinder or a portable air pump as the gas source 100, ensuring stable gas output and that the gas is oil-free and water-free. After the gas is regulated to the target test pressure by the pressure reducing valve 101, its flow is controlled by the switching valve 102, and it is then input into the sealing device 11. The design of the air intake device 10 ensures the consistency and repeatability of test conditions, while preventing impurities from entering the valve under test and causing secondary contamination or misjudgment. The sealing device 11 is connected to the air intake device 10 and is used to accommodate and fix the spherical sealing valve under test, simulating its two sealing states in the high-pressure stage regulator assembly of the aircraft bleed air system. The internal cavity 115 structure of the sealing device 11 is matched with the actual shape of the spherical sealing valve to ensure that each component of the valve can be accurately positioned. By replacing or adjusting the internal limiting structure, the directional constraint of the ceramic ball 20 position can be achieved: in one configuration, the ceramic ball 20 is pre-tightened towards the lift valve seat 21 to form a low-pressure sealing pair test mode; in another configuration, it is pressed towards the valve mounting seat 22 to enter the high-pressure sealing pair test mode. The two test modes correspond to different gas flow paths and sealing boundaries, forming independent test gas paths to avoid cross-interference.

[0028] Specifically, the flow monitoring unit 120 can be used to acquire the volumetric flow rate of the leaked gas in real time and realize quantitative analysis; the differential pressure monitoring unit 121 is used to monitor the pressure changes at the inlet and outlet of the sealing device 11 during the test, and assist in judging the sealing stability and system response characteristics; through the joint monitoring of the two units, not only can accurate leakage data be obtained, but also transient fluctuations or nonlinear leakage behavior can be identified, thereby improving detection sensitivity.

[0029] Furthermore, the sealing device 11 is configured to perform low-pressure sealing tests between the ceramic ball 20 of the spherical sealing valve and the lift valve seat 21, and high-pressure sealing tests between the ceramic ball 20 and the valve mounting seat 22, respectively, by replacing or adjusting the internal limiting structure. This design allows the same device to adapt to two completely different sealing configurations without the need for additional development of special fixtures or repeated investment in equipment. The limiting structure can take the form of mechanical pins, removable blocks, threaded adjustment parts, etc., as long as it can effectively control the axial and radial positions of the ceramic ball 20. For example, in one embodiment, the clamping direction of the ceramic ball 20 can be switched by replacing the axial limiting blocks 114 at different heights; in another embodiment, the two test modes can be automatically switched by a rotary switching mechanism, improving operational convenience. Because sealing defects between the ceramic ball 20 and the lift valve seat 21, and between the ceramic ball 20 and the valve mounting seat 22 can be identified before assembly, the problems of frequent rework, difficult troubleshooting, and high maintenance costs caused by the lack of early detection methods in the prior art are solved. Therefore, the technical effects of improving the first-pass yield of assembly, shortening the maintenance cycle, and reducing operating costs are achieved. At the same time, by integrating quantitative and qualitative dual detection capabilities, the reliability of test results and the diversity of criteria are enhanced, providing a reliable tool for the quality control of key aviation components.

[0030] Understandably, the various components are physically connected and transmit signals through pipes and interfaces. The intake device 10 delivers clean gas at a set pressure into the sealing device 11. The gas acts on the surface of the ceramic ball 20 and attempts to leak through any possible gaps. If there is a defect in the sealing pair, the gas will escape along the leakage path and enter the detection device 12 through the outlet of the sealing device 11. The flow monitoring unit 120 records the leakage amount per unit time, and the differential pressure monitoring unit 121 simultaneously collects the pressure difference between the inlet and outlet; both together constitute a complete performance evaluation basis. By comparing the measured data with the standard threshold, it can be determined whether the valve meets the bidirectional sealing requirements.

[0031] Furthermore, the differential pressure monitoring unit 121 includes a first pressure sensor 1210 and a second pressure sensor 1211; the first pressure sensor 1210 is disposed at the air inlet 110 of the sealing device 11, and the second pressure sensor 1211 is disposed at the air outlet 111 of the sealing device 11; the differential pressure monitoring unit 121 is configured to calculate and display the real-time differential pressure inside and outside the sealing device 11 based on the readings of the first pressure sensor 1210 and the second pressure sensor 1211.

[0032] Understandably, the above technical solution, by introducing a dual-point pressure sensor and a real-time differential pressure calculation mechanism, achieves dynamic monitoring of the pressure state at both ends of the sealing pair during the test. Specifically, the first pressure sensor 1210 collects the gas pressure value before entering the sealing device 11, i.e., the upstream gas supply pressure, reflecting the actual pressure level applied to the inlet side of the sealing pair. The second pressure sensor 1211 is located at the outlet port 111 of the sealing device 11, used to detect pressure changes at the outlet end of the leakage channel. The two sensors work synchronously, transmitting their respective measured pressure signals to the data processing module. The system automatically calculates and outputs the effective differential pressure currently acting on the sealing structure based on the difference between the two sensors, which can be displayed in real time via a screen or host computer interface. In particular, this arrangement allows for accurate reproduction and recording of the pressure environment during the test. The first pressure sensor 1210 is positioned close to the air inlet 110 to ensure accurate sensing of whether the adjusted test pressure has stabilized and met the preset operating conditions, avoiding misjudgments caused by fluctuations in the pressure reducing valve 101 or pipeline pressure loss. The second pressure sensor 1211 is located at the air outlet and can sensitively respond to pressure accumulation caused by minor leaks. Especially in high-pressure sealing tests, it helps to identify the initial leak point and the development trend of the leak. The two sensors work together to form a closed-loop differential pressure feedback system, which not only improves the controllability of test conditions but also provides key reference data for the analysis of leakage data.

[0033] As an optional implementation, the pressure sensor used in the differential pressure monitoring unit 121 can be a high-precision diffused silicon pressure sensor, which has good linearity, repeatability, and temperature stability. Alternatively, it can be replaced with a pressure sensing unit of the same model but with a different range. For example, a 0-1MPa range sensor can be used in low-pressure test mode to improve resolution, while switching to a 0-5MPa wide range version during high-pressure test, thus balancing measurement accuracy and adaptability. In addition, an intelligent pressure transmitter with built-in temperature compensation function can also be used to eliminate the influence of ambient temperature changes on the measurement results and improve the reliability of long-term operation.

[0034] Further, the sealing device 11 includes: a sealing housing assembly 112, including a first housing 1120 and a second housing 1121 that are detachably connected, the shape of its inner cavity 115 matching the shape of the spherical sealing valve; at least one radial limiting block 113 disposed in the wall of the inner cavity 115 for radially limiting the ceramic ball 20; at least one axial limiting block 114 disposed in the inner cavity 115 for axially limiting the lift valve seat 21 or the valve mounting seat 22; wherein the first housing 1120 and / or the second housing 1121 are provided with an air inlet 110 and an air outlet 111.

[0035] Understandably, the sealing device 11, through its structured design, achieves precise positioning and stable clamping of the spherical sealing valve under different sealing conditions, ensuring that the stress state of the sealing pair during the test truly reflects the actual working conditions. This device employs a modular, detachable housing structure with dedicated limiting elements, enabling it to independently complete bidirectional sealing performance testing of the valve without relying on the high-pressure stage regulator assembly.

[0036] Specifically, the sealing housing assembly 112 is composed of a first housing 1120 and a second housing 1121 connected in a detachable manner. Threaded connections, flange connections, or quick-release snap-fit ​​structures can be used for easy assembly and disassembly, improving testing efficiency. The contour of the inner cavity 115 formed by the two housings is highly matched to the shape of the spherical sealing valve under test, effectively restricting the overall spatial freedom of the valve and preventing it from shifting or shaking during testing. The housing material can be stainless steel or other high-strength metal materials, possessing good pressure resistance and deformation resistance, suitable for multiple cycle tests in the low-pressure to high-pressure range. The design of the inner cavity 115 not only considers external geometric adaptation but also reserves necessary flow channel space to ensure uniform gas distribution and avoid local eddies affecting leakage measurement accuracy.

[0037] Specifically, at least one radial limiting block 113 is disposed on the wall of the inner cavity 115 to apply circumferential constraint to the ceramic ball 20, restricting its movement in the horizontal direction; its inner diameter is slightly larger than the diameter of the ceramic ball 20, which can achieve light contact positioning and avoid damage to the surface of the ceramic ball 20 or stress concentration due to excessive clamping; optionally, the surface of the limiting block can be covered with polytetrafluoroethylene (PTFE) or a rubber buffer layer to reduce friction and protect the mirror sealing area of ​​the ceramic ball 20. This structure ensures that the ceramic ball 20 is always in the centered position during testing, ensuring the consistency of the line contact seal between it and the valve seat or mounting base; At least one axial limiting block 114 is disposed in the inner cavity 115 to limit the axial position of the lift valve seat 21 or the valve mounting seat 22. Depending on different test requirements, the position of the axial limiting block 114 can be replaced or adjusted to adapt to the installation depth of different components; specifically, during low-pressure sealing tests, the axial limiting block 114 supports the lift valve seat 21, ensuring that its end face accurately fits the ceramic ball 20; while during high-pressure sealing tests, it is replaced with a limiting structure adapted to the valve mounting seat 22 to ensure that the ceramic ball 20 is correctly pressed against the sealing surface of the mounting seat.

[0038] Understandably, the use of a detachable housing and a dedicated limiting structure ensures that the ceramic ball 20 maintains the correct spatial orientation during testing, improving the repeatability and reliability of the sealing contact. Simultaneously, by applying appropriate axial constraints to different components, the stress environment under both low-pressure and high-pressure conditions is realistically reproduced, making the measured leakage data more representative and providing engineering guidance. This structural design not only solves the problem of existing technologies being unable to conduct bidirectional sealing testing at the component level but also provides a feasible technical path for the development of subsequent automated testing equipment.

[0039] Furthermore, the flow monitoring unit 120 is a float flow meter, and its inlet is connected to the air outlet 111 of the sealing device 11 through a pipeline.

[0040] Understandably, by using a float flowmeter as the flow monitoring unit 120 and connecting its inlet end to the outlet port 111 of the sealing device 11 via a pipeline, continuous, intuitive, and quantifiable measurement of the test gas leaking from the spherical sealing valve is achieved. As a classic instrument based on the equilibrium position of a float within a conical tube reflecting fluid flow, the float flowmeter has advantages such as simple structure, rapid response, no need for external power supply, and low maintenance costs, making it particularly suitable for monitoring minute gas flow rates in field operating environments.

[0041] Specifically, the flow monitoring unit 120 employs a float flow meter, a variable area flow meter operating on the principle of constant pressure drop. Its basic structure includes a vertically mounted transparent conical glass tube and a float that can move freely up and down within the tube. When gas flows upward through the conical tube, a pressure difference is generated in the annular channel formed between the float and the tube wall, pushing the float upward. When the lift force on the float balances its weight, the float stabilizes at a certain height, corresponding to the current gas flow rate, which can be directly read using an external scale. The measurement range of the float flow meter can be selected according to actual needs; in this embodiment, a small flow rate range of 0–50 mL / min is selected to meet the accuracy requirements for detecting minute leaks in aerospace-grade seals.

[0042] As an alternative implementation, the float flow meter can be replaced with other types of gas flow sensors, such as thermal mass flow meters or differential pressure flow meters, which are particularly advantageous in applications requiring higher-precision digital output or remote data acquisition. Thermal mass flow meters, based on the principle of heat conduction, can directly output mass flow signals under standard conditions, unaffected by temperature and pressure fluctuations; differential pressure flow meters, on the other hand, can achieve linearized output by combining laminar flow elements, making them suitable for integration into automated testing systems.

[0043] Specifically, after the sealing device 11 completes the assembly of the spherical sealing valve to be tested and applies the test pressure, if a leak occurs, the leaking gas will flow out along the outlet port 111, enter the inlet of the float flowmeter through the connecting pipeline, and push the float up to the corresponding position. The operator can observe the scale value after the float stabilizes in real time to obtain quantitative leakage data. The entire gas path is clear and the passage is smooth, ensuring the consistency and repeatability of the measurement process.

[0044] Furthermore, the detection device 12 also includes a leak indicator medium unit 122, which is a transparent container filled with liquid, and the outlet pipe of the float flowmeter extends below the liquid surface of the transparent container.

[0045] Understandably, through the above technical solution, this application achieves qualitative auxiliary judgment and visual tracing of minute leakage amounts. This implementation method introduces an intuitive and low-cost bubble observation mechanism on the basis of the original quantitative detection, enhancing the reliability of the detection results and the on-site operability.

[0046] Specifically, the leak indicator unit 122 serves as the terminal emission and visualization module for leaked gas, and its core component is a transparent container filled with liquid. This container receives the test gas discharged from the float flowmeter and visually determines the leak status by observing the formation of bubbles in the liquid. The transparent material allows operators to observe the internal situation from multiple angles, ensuring blind-spot-free monitoring; the container has a moderate capacity, capable of holding a certain volume of liquid and maintaining sufficient depth to form a stable gas-liquid interface. Specifically, the leak indicator medium is pure water, which has the advantages of low cost, high safety, and easy availability, and does not chemically react with the test gas, making it suitable for common gas source environments such as compressed air or nitrogen. In other optional embodiments, the leak indicator medium can also be replaced with a low-viscosity transparent liquid (such as silicone oil or ethanol solution) to adapt to application scenarios with low temperature or special gas compositions, improve bubble formation stability, or prevent freezing.

[0047] Understandably, the leak indicator unit 122 and the float flowmeter together constitute a dual detection mode of "quantitative + qualitative"; the float flowmeter provides accurate flow rate output, meeting standardized measurement requirements; while the bubble phenomenon generated by underwater venting provides immediate and intuitive visual feedback, compensating for potential lag or insufficient resolution in instrument readings. The combination of these two features allows even extremely small leaks to be reliably detected, significantly improving the overall judgment capability of the detection system.

[0048] Furthermore, the sealing housing assembly 112 also includes a rubber sealing ring 1122 disposed in the sealing groove of the lift valve seat 21 and the valve mounting seat 22, for achieving a static seal between the sealing housing assembly 112 and the valve under test.

[0049] Understandably, by introducing an elastic sealing structure at the interface between the sealing housing assembly 112 and the spherical sealing valve under test, the gas leakage path outside the test path is effectively blocked, ensuring that the leakage measured during the test truly reflects the actual sealing performance of the target sealing pair. Among them, the rubber sealing ring 1122, as a key component, is pre-placed in the sealing groove of the inner cavity 115 of the sealing housing assembly 112 corresponding to the outer periphery of the lift valve seat 21 and the valve mounting seat 22. When the valve component under test is installed, the sealing ring undergoes radial compression deformation under the action of axial clamping force, filling the micro gaps between the metal components and forming a reliable static sealing interface.

[0050] Specifically, the rubber sealing ring 1122 is an O-ring structure with a circular cross-section. The material can be fluororubber or nitrile rubber, and it has good high temperature resistance, compression set resistance and chemical stability to compressed air or nitrogen media.

[0051] Furthermore, the air intake device 10 includes an air source 100, a pressure reducing valve 101, and a switching valve 102. The air source 100 is a high-pressure air storage cylinder or an air pump, and the gas provided by the air source 100 is compressed air or nitrogen.

[0052] Specifically, the air intake device 10 is used to provide the testing system with stable, clean, and pressure-controllable test gas to simulate the gas input conditions under different operating conditions in an aircraft bleed air system. This device, through the rational configuration of the gas source 100 type and key control components, achieves comprehensive assurance of the safety, adjustability, and applicability of the testing process.

[0053] The pressure reducing valve 101 is located at the outlet of the gas source 100 and is used to adjust the high-pressure gas from the gas source 100 to the required test pressure range. The pressure reducing valve 101 has pressure setting, pressure stabilization output and overpressure protection functions to ensure that the gas pressure entering the sealing device 11 is constant and meets the preset standard, and to avoid the leakage measurement accuracy being affected by pressure fluctuations.

[0054] The switching valve 102 is located upstream of the pressure reducing valve 101 and is used to control the flow of test gas. The operator can open and close the switching valve 102 manually or by electromagnetic drive. It is closed before the test starts to isolate the gas path, and the gas supply is turned on after the connection is confirmed to be correct. After the test is completed, the gas flow is cut off in time to prevent continuous gas leakage or accidental release.

[0055] To address the aforementioned technical problems, this invention also provides a method for detecting bidirectional leakage of a spherical sealing valve in an aircraft bleed air system using the detection system described in the above embodiments, comprising the following steps: S1, Low-pressure sealing performance test: S10, the lift valve seat and ceramic ball are installed into the sealing device and limited by radial and axial limit blocks; Specifically, the lift valve seat is one of the key static components in a spherical sealing valve. It is typically made of stainless steel or high-temperature alloy and features a precision-machined conical sealing structure, used to form a line-contact sealing pair with the ceramic ball under low-pressure conditions. The ceramic ball, as a dynamic sealing element, undergoes high-precision grinding, possessing extremely high roundness and surface finish. It can tightly conform to the sealing surface of the lift valve seat under pressure, achieving effective shut-off. The inner cavity of the sealing device is designed with a stepped through-hole structure that matches the shape of the assembly, ensuring no eccentricity or tilting during assembly.

[0056] Radial limiting blocks are located within the inner cavity of the sealing housing assembly. They are annular or segmented retaining rings, made of materials such as PTFE, nylon, or metal elastic elements. These blocks constrain the lateral displacement of the ceramic ball under gas pressure, preventing it from deviating from the central axis and causing seal failure. Axial limiting blocks are positioned at the end support of the lift valve seat. They typically employ threaded pressure rings, elastic gaskets, or stepped retaining rings to limit excessive axial movement, thereby ensuring stable transmission of the sealing preload.

[0057] This installation method accurately simulates the sealing pair between the ceramic ball and the lift valve seat, allowing the test conditions to be replicated as closely as possible to the actual working conditions in the high-pressure stage regulator assembly of the aircraft bleed air system.

[0058] S11 connects the intake device and the detection device; Specifically, the air intake device includes an air source, a pressure reducing valve, and a switching valve. The air source can be a high-pressure gas cylinder or a portable compressed air pump, and the output gas is clean and dry compressed air or nitrogen to avoid moisture or oil contamination of the tested sealing surface and its impact on the test results. The pressure reducing valve is used to reduce the original high-pressure gas to the required test pressure range; the switching valve controls the gas flow and is preferably a two-position two-way solenoid valve or a manual ball valve, which provides rapid response and reliable sealing.

[0059] The detection device is connected to the outlet of the sealing device via a pressure-resistant hose and includes a flow monitoring unit (such as a float flow meter) and a differential pressure monitoring unit (composed of a first pressure sensor and a second pressure sensor). All connection interfaces use standard quick-connect couplings or O-ring sealing flanges to ensure good overall airtightness of the system and avoid external leakage from interfering with measurement accuracy.

[0060] S12, turn on the air source and adjust the inlet pressure to the specified low-pressure test pressure; Specifically, the low-pressure test is conducted according to aerospace industry standards, at pressures of 35-36 psig and 100-101 psig, to ensure its sealing performance under these conditions. During operation, the valve is opened slowly, and the pressure is gradually increased to the target value to avoid instantaneous impact that could cause the ceramic ball to bounce or damage the sealing surface. After the pressure stabilizes, it is held for at least 60 seconds to allow the system to reach thermodynamic equilibrium, ensuring stable and reliable subsequent readings.

[0061] S13, observe and record stable leakage values ​​and real-time differential pressure data through the detection device; Specifically, the flow monitoring unit displays the volumetric flow rate of gas leaking from the sealing joint in real time. A typical device is a glass tube float flow meter, and the range can be selected according to the expected leakage rate (e.g., 0–10 mL / min or 0–100 mL / min), with a minimum resolution of 1 mL / min. When the float position fluctuates less than ±2% of the full scale for 30 consecutive seconds, it is considered to have reached a steady state, and the value read at this time is taken as the quantitative leakage amount.

[0062] Simultaneously, the differential pressure monitoring unit collects the first pressure value P1 at the inlet and the second pressure value P2 at the outlet, calculating the difference ΔP = P1 - P2, which reflects the pressure drop at the front and rear ends of the sealing pair. Under normal circumstances, if the seal is good, ΔP is close to the inlet pressure; if there is significant leakage, ΔP decreases significantly. This data can be used to help determine leakage trends and seal integrity.

[0063] In addition, the leak indicator unit can provide qualitative criteria: if the end of the float flowmeter outlet pipe is immersed to a depth of about 10-20 mm below the liquid surface, and continuous visible bubbles are continuously generated, it indicates that there is a leak exceeding the allowable threshold, and even if the flowmeter reading is low, it should raise a red flag.

[0064] S2, High-pressure sealing performance test: S20, disassemble the sealing device and remove the lift valve seat and ceramic ball; Specifically, after completing the low-pressure test, shut off the gas supply and release the residual pressure. Disassemble the connecting structure between the sealing housing components, carefully remove the tested lift valve seat and ceramic ball, avoiding scratching the inner cavity or limiting structure; clean the old rubber sealing ring in the sealing groove, check whether the sealing ring installation area is clean and free of foreign objects, and replace it with a new sealing ring if necessary to ensure the reliability of subsequent tests.

[0065] S21, Install the valve mounting base and ceramic ball into the sealing device, and use the axial limiting block to limit it before reconnecting the pipeline; Specifically, during installation, first place the valve mounting seat into the corresponding cavity of the sealing housing, then insert the ceramic ball, and finally fix its axial position using the axial limiting block. In this condition, the axial limiting block primarily serves a dual function of support and limitation, preventing high-pressure gas from pushing the ceramic ball downstream and causing it to disengage from the sealing position. This limiting block can be designed as a replaceable module to adapt to the structural dimensions of different valve models, improving the versatility of the detection device. After reconnecting the pipeline, a simple airtightness check should be performed. Briefly pressurizing the flow meter and observing for non-zero readings can preliminarily determine if there is a connection leak.

[0066] S22, turn on the gas source and set the inlet pressure to the specified high-pressure test pressure; Specifically, high-pressure sealing performance testing should be conducted under inlet pressures of 35-36 psig and 100-101 psig respectively to ensure its sealing performance under various pressure conditions. In actual operation, due to the high pressure level, special attention should be paid to safety protection measures, such as installing pressure relief valves, setting up protective covers, and wearing safety goggles. The pressurization process should be carried out slowly, and the system response should be observed until the target pressure is reached and maintained stably for at least 90 seconds.

[0067] S23, observe and record stable leakage values ​​and real-time differential pressure data through a detection device; It should be noted that under high pressure, ceramic balls may undergo slight elastic deformation or localized stress concentration, causing what was originally effective line contact to become surface contact or even partial separation. Therefore, this stage is more likely to expose material defects or processing errors. This step can effectively identify potential high-pressure sealing hazards.

[0068] S3. Compare the leakage and differential pressure data measured in steps S1 and S2 with the standard requirements to verify the bidirectional sealing performance of the spherical sealing valve.

[0069] Specifically, the data obtained include leakage Q1 and pressure difference ΔP1 under low-pressure testing, and leakage Q2 and pressure difference ΔP2 under high-pressure testing; these parameters need to be compared with the pre-defined technical specification limits respectively.

[0070] Specifically, according to aviation industry standards and technical specifications, the testing standards are limited to: If Q1≤5mL / min and ΔP1≥90%, or no more than 43 bubbles per minute, then the low-pressure seal is deemed qualified. If Q2≤50mL / min and ΔP2≥85%, and no continuous bubbles are generated, then the high-pressure seal is deemed qualified. Only when both tests are passed can the spherical sealing valve be deemed to have complete bidirectional sealing capability and be allowed to proceed to the next assembly stage.

[0071] Optionally, the comparison process can be completed manually or integrated into an automated testing platform, where the host computer software automatically collects, stores, analyzes, and generates test reports, supporting quality traceability and batch management.

[0072] Furthermore, steps S13 and S23 specifically include: reading the stable reading of the float flowmeter as the quantitative leakage flow value; and visually observing whether there are continuous bubbles generated in the leakage indicator medium unit as the basis for qualitative leakage judgment.

[0073] Specifically, once the inlet pressure reaches the specified value and remains stable, and the float position within the float flowmeter no longer fluctuates significantly, the corresponding scale value of the float is recorded. This scale value represents the volumetric flow rate of gas leaking into the detection device through the outlet port per unit time. The leak indicator medium unit consists of a transparent container filled with water, with the end of the float flowmeter's outlet pipe submerged to a certain depth below the liquid surface. If there is a leak in the sealing pair, gas will enter the water along the pipe and form bubbles. If only sporadic, intermittent bubbles appear, it may be due to the release of residual air in the system; however, a continuous string of bubbles clearly indicates the existence of a stable leak path. This observation method has high sensitivity, especially for minor leaks, providing supplementary identification capabilities and significantly improving the reliability and anti-interference ability of the detection results.

[0074] Furthermore, before step S1, there is also a detection device sealing self-test step S0, in which the inner cavity of the sealing device is closed without the ball-shaped sealing valve installed, test pressure is introduced, and the leakage reading of the detection device is observed to see if it is within the specified range.

[0075] Optionally, the specific values ​​within the specified range can be set according to the testing accuracy requirements, or determined according to industry standards or enterprise specifications.

[0076] Understandably, by removing the test piece and constructing a no-load, closed test loop, applying representative pressure with a controllable gas source, and monitoring background leakage levels using a high-sensitivity flow meter, independent verification of the sealing integrity of the testing system's main body is achieved. This process essentially constitutes a pre-test quality control mechanism, ensuring that subsequent bidirectional leakage test data for the spherical valve accurately reflects the performance of the test piece, rather than being affected by leakage within the device itself. This solves the technical problem of distorted test results and misjudgments of valve performance due to poor device sealing, thus improving testing accuracy and reliability.

[0077] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0078] Furthermore, it should be noted that the scope of the methods and apparatus in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

[0079] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A detection system for detecting bidirectional leakage of a spherical sealing valve in an aircraft bleed air system, the spherical sealing valve comprising a ceramic ball, a lift valve seat, and a valve mounting seat, wherein the ceramic ball is selectively pressed against the lift valve seat or the valve mounting seat during valve operation to form two different sealing pairs, characterized in that... The detection system includes: An air intake device is used to provide test gas with controllable pressure and cleanliness; A sealing device, connected to the air intake device, is used to accommodate and fix the spherical sealing valve to be tested, and to simulate its two sealing states in the high-pressure stage regulator assembly of the aircraft bleed air system, so as to form two independent test air paths. A detection device is provided on opposite sides of the gas path of the sealing device for quantitative detection and / or qualitative tracing of the gas flow rate leaking from the sealing device. The detection device includes a flow monitoring unit and a differential pressure monitoring unit. The sealing device is configured to perform low-pressure sealing tests between the ceramic ball of the spherical sealing valve and the valve seat of the lift valve, and high-pressure sealing tests between the ceramic ball and the valve mounting seat, respectively, by replacing or adjusting the internal limiting structure.

2. The detection system according to claim 1, characterized in that, The differential pressure monitoring unit includes a first pressure sensor and a second pressure sensor; the first pressure sensor is located at the air inlet of the sealing device, and the second pressure sensor is located at the air outlet of the sealing device; the differential pressure monitoring unit is configured to calculate and display the real-time differential pressure inside and outside the sealing device based on the readings of the first pressure sensor and the second pressure sensor.

3. The detection system according to claim 2, characterized in that, The sealing device includes: The sealing housing assembly includes a detachably connected first housing and a second housing, the shape of which matches the shape of the spherical sealing valve. At least one radial limiting block is disposed in the inner cavity for radially limiting the ceramic ball; At least one axial limiting block is disposed in the inner cavity for axially limiting the lifting valve seat or the valve mounting seat; The first housing and / or the second housing are provided with the air inlet and air outlet.

4. The detection system according to claim 3, characterized in that, The flow monitoring unit is a float flow meter, and its inlet is connected to the air outlet of the sealing device through a pipeline.

5. The detection system according to claim 4, characterized in that, The detection device also includes a leak indicator medium unit, which is a transparent container filled with liquid, and the outlet pipe of the float flowmeter extends below the liquid surface of the transparent container.

6. The detection system according to claim 3, characterized in that, The sealing housing assembly also includes a rubber sealing ring disposed in the sealing groove of the lift valve seat and the valve mounting seat, for achieving a static seal between the sealing housing assembly and the valve under test.

7. The detection system according to claim 1, characterized in that, The air intake device includes an air source, a pressure reducing valve, and a switching valve. The air source is a high-pressure gas cylinder or an air pump, and the gas provided by the air source is compressed air or nitrogen.

8. A method for detecting bidirectional leakage of a spherical sealing valve in an aircraft bleed air system using the detection system as described in any one of claims 1-7, characterized in that, Includes the following steps: S1, Low-pressure sealing performance test: S10, the lifting valve seat and ceramic ball of the spherical sealing valve are installed into the sealing device, and the radial limiting block and axial limiting block are used to limit it; S11, connecting the air intake device and the detection device; S12, turn on the air source and adjust the inlet pressure to the specified low-pressure test pressure; S13, observe and record stable leakage values ​​and real-time differential pressure data through the detection device; S2, High-pressure sealing performance test: S20, disassemble the sealing device and remove the lift valve seat and the ceramic ball; S21, install the valve mounting base and the ceramic ball into the sealing device, and use the axial limiting block to limit them before reconnecting the pipeline; S22, turn on the gas source and set the inlet pressure to the specified high-pressure test pressure; S23, observe and record stable leakage values ​​and real-time differential pressure data through the detection device; S3. Compare the leakage and differential pressure data measured in steps S1 and S2 with the standard requirements to verify the bidirectional sealing performance of the spherical sealing valve.

9. The detection method according to claim 8, characterized in that, Steps S13 and S23 specifically include: reading the stable reading of the float flowmeter as the quantitative leakage flow value; and visually observing whether there are continuous bubbles generated in the leakage indicator medium unit as the basis for qualitative leakage judgment.

10. The detection method according to claim 8, characterized in that, Before step S1, there is also a detection device sealing self-test step S0: without installing the ball-shaped sealing valve, the inner cavity of the sealing device is closed, test pressure is introduced, and the leakage reading of the detection device is observed to see if it is within the specified range.

Images