An experimental device and experimental method for verifying the sealing performance of high-temperature wires

Abstract

An experimental device and experimental method for verifying the sealing performance of high-temperature wires, belonging to the technical field of experimental evaluation of wire sealing performance in aerodynamic wind tunnels. It solves the problem in the prior art that the sealing evaluation of wire sealing structures cannot be carried out under different temperatures, different pressures, and different compaction forces. Technical key points: Verify the sealing performance of the seal under different temperatures, verify the sealing performance of the seal under different compaction forces, verify the sealing performance of the seal under different pressures, and obtain the temperature coefficient curve based on the experimental data, and obtain the functional relationship between the clearance height between the flexible graphite packing and the sealing baffle and the compaction force. By verifying the sealing ability of the sealing structure and accurately measuring the leakage amount under different working conditions, the present invention can ensure the stability and controllability of the internal flow field of the wind tunnel, ensure that the experimental data truly reflects the physical laws of hypersonic flow, and provide a reliable basis for aircraft design and related theoretical research.

Description

Technical Field

[0001] The present invention relates to the technical field of experimental evaluation of the airtight performance of aviation aerodynamic wind tunnel lines, and particularly to an experimental device and an experimental method for verifying the high-temperature airtight performance of wires. Background Technique

[0002] During the hypersonic wind tunnel experiment, the sealing structure between the flexible nozzle and the side wall faces many problems. A large amount of heat is generated when the air flow passes through the nozzle, causing the temperatures of the flexible nozzle and the side wall to rise sharply. Generally speaking, the temperature in the hypersonic wind tunnel experiment may reach 500 °C or even higher. At such high temperatures, ordinary sealing materials will quickly age, deform or even melt, resulting in a decline in the sealing performance. At the same time, the pressure inside the wind tunnel will fluctuate violently due to factors such as unstable air flow. The rapid change of pressure will cause the sealing structure to bear alternating stress, which easily leads to fatigue damage of the seal and reduces the sealing effect. The large-scale pressure change increases the difficulty of sealing.

[0003] Therefore, it is extremely important to verify the performance of the sealing device. The existing verification devices are mainly divided into the following types: a high-temperature sealing performance test device for refractory sealing materials, which can accurately evaluate the sealing effect of the sealing materials used for high-temperature wires at high temperatures, provide strong support for the selection and improvement of materials, and can effectively evaluate the sealing reliability of high-temperature wires under extreme conditions; a hot air aging test chamber device, which has a relatively simple structure and an intuitive operation interface. Operators can start operating after simple training, reducing the labor cost and operation difficulty.

[0004] The existing verification sealing devices also have many limitations. The simulated working conditions are single, and only the high-temperature environment can be simulated, and other complex working conditions such as high pressure cannot be simulated simultaneously; the test time is long, resulting in low test efficiency and unable to obtain test results quickly; it is mainly used for static tests and cannot simulate the dynamic movement of high-temperature wires during actual work, and the evaluation ability for dynamic sealing performance is limited.

[0005] Therefore, there is an urgent need to propose an experimental device and an experimental method for verifying the high-temperature airtight performance of wires to solve the problem that the airtight evaluation of the wire sealing structure cannot be carried out at different temperatures, different pressures and different pressing forces in the prior art. Summary of the Invention

[0006] In view of the above facts, in order to solve the problem that the airtight evaluation of the wire sealing structure cannot be carried out at different temperatures, different pressures and different pressing forces in the prior art, the present invention further designs an experimental device and an experimental method for verifying the high-temperature airtight performance of wires.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] Solution 1: An experimental device for verifying the sealing performance of high-temperature wires, comprising a rectangular container, a temperature sensor, a pressure sensor, a temperature-controlled electric heating rod, an adjusting rod, a cover plate, a sealing member, a second sealing press block, a first sealing press block, a high-temperature alloy spring, a sealing baffle, an air inlet, an exhaust port, and a slotted wall plate;

[0009] The cover plate is installed on the right side of the rectangular container, and the sealing baffle is welded inside the rectangular container, dividing the rectangular container into a left chamber and a right chamber. The air inlet is arranged on the left side of the rectangular container and communicates with the left chamber, and the exhaust port is arranged on the right side of the cover plate and communicates with the right chamber;

[0010] The rectangular container is inserted with a temperature sensor, a pressure sensor, and a temperature-controlled electric heating rod, and the detection ends of the temperature sensor, the detection end of the pressure sensor, and the heating end of the temperature-controlled electric heating rod are all located in the left chamber;

[0011] The slotted wall plate is welded inside the rectangular container and is located in the right chamber. The sealing member is embedded between the sealing baffle and the slotted wall plate. The second sealing press block is installed on the sealing member. The adjusting rod passes through the upper wall plate of the rectangular container and is connected to the first sealing press block. The two ends of the high-temperature alloy spring are respectively embedded in the first sealing press block and the second sealing press block;

[0012] A gap is left between the lower end of the sealing baffle and the rectangular container, and the height of the gap is 2 mm;

[0013] A gap is left between the lower end of the slotted wall plate and the rectangular container, and the height of the gap is 2 mm.

[0014] Further: A chute is arranged on the right side of the sealing baffle, and the first sealing press block and the second sealing press block are installed in the chute.

[0015] Further: The first sealing press block and the second sealing press block are both milled with 8 circular grooves with a diameter of 12 mm and a depth of 1 mm, and eight high-temperature alloy springs are placed in the circular grooves.

[0016] Further: The material of the high-temperature alloy spring is GH4145, the diameter of the spring wire is 2 mm, the mean diameter of the spring is 10 mm, and the number of turns is 14.5.

[0017] Further: The internal volume of the rectangular container is 180 mm × 180 mm × 115 mm;

[0018] The length of the sealing member is 20 mm, the width is 180 mm, and the height is 20 mm.

[0019] Solution 2: An experimental method for verifying the sealing performance of high-temperature wires, which is realized relying on the experimental device for verifying the sealing performance of high-temperature wires described in Solution 1, and the operation process is as follows:

[0020] Step 1: Verify the sealing performance of the seal at different temperatures;

[0021] Control the pressure in the rectangular container to 1.2 MPa and the compaction force to 300 N. Measure the pressure drop in the rectangular container per unit time at temperatures of 200 °C, 250 °C, 300 °C, 350 °C, 400 °C, 450 °C, and 500 °C respectively, so as to judge the sealing performance of the seal at different temperatures;

[0022] Step 2: Verify the sealing performance of the seal under different compaction forces;

[0023] Control the initial temperature in the rectangular container to 500 °C and the pressure to 1.2 MPa. Close the valve at the air inlet, keep the temperature unchanged, change the length of the adjusting rod, and measure the pressure drop in the rectangular container per unit time at compaction forces of 100 N, 150 N, 200 N, 250 N, 300 N, 350 N, 400 N, 450 N, 500 N, 600 N, 700 N, 800 N, 900 N, and 1000 N respectively, so as to judge the sealing performance of the seal under different compaction forces;

[0024] Step 3: Verify the sealing performance of the seal under different pressures;

[0025] Control the initial temperature in the rectangular container to 500 °C and the compaction force to 400 N. Measure the pressure drop in the rectangular container per unit time at pressures of 0.6 MPa, 0.8 MPa, 1.0 MPa, 1.2 MPa, 1.4 MPa, 1.6 MPa, 1.8 MPa, and 2.0 MPa respectively, so as to judge the sealing performance of the seal under different pressures;

[0026] Step 4: The inside of the seal is filled with flexible graphite packing. According to the experimental data in Steps 1 to 3, obtain the temperature coefficient curve, and obtain the functional relationship between the clearance height between the flexible graphite packing and the seal baffle and the compaction force. The calculation formula is:

[0027] ;

[0028] where is the clearance height between the seal and the seal baffle;

[0029] F is the compaction force;

[0030] Both k and n are constants, and n is a positive number.

[0031] The beneficial effects of the present invention are as follows:

[0032] 1. Through multi-condition evaluation, the present invention can more accurately master the performance characteristics and applicable scope of the linear seal structure, and can comprehensively understand its sealing ability under various complex working conditions.

[0033] 2. By verifying the sealing ability of the sealing structure and accurately measuring the leakage amount under different working conditions, the present invention can ensure the stability and controllability of the internal flow field of the wind tunnel, guarantee that the experimental data truly reflects the physical laws of hypersonic flow, and provide a reliable basis for aircraft design and related theoretical research.

[0034] 3. The present invention provides an important reference for the design and optimization of the wind tunnel. Engineers can specifically improve the design of the sealing structure, select more suitable sealing materials and sealing methods, enhance the sealing performance of the wind tunnel, reduce energy loss, and lower the operating cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a cross-sectional view of the experimental equipment in the present invention;

[0036] Figure 2 is a top view of the experimental equipment in the present invention.

[0037] In the figure: 1 - rectangular container, 2 - temperature sensor, 3 - pressure sensor, 4 - temperature-controlled electric heating rod, 5 - adjusting rod, 6 - cover plate, 7 - seal, 8 - second sealing block, 9 - superalloy spring, 10 - sealing baffle, 11 - air inlet, 12 - exhaust port, 13 - first sealing block, 14 - slotted wall panel. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] In order to enable those skilled in the art of the present technology to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0039] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances for the embodiments of the present application described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0040] In this application, the orientation or positional relationship indicated by terms such as "upper", "lower", "inner", "middle", "outer", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe this application and its embodiments, and are not used to limit that the indicated device, element, or component must have a specific orientation, or be constructed and operated in a specific orientation.

[0041] Moreover, in addition to being able to represent the orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to the specific circumstances.

[0042] In addition, the terms "arranged", "connected", and "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or there can be internal communication between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0043] It should be noted that, without conflict, the embodiments and features in the embodiments of this application can be combined with each other. The following will refer to the drawings and combine with the embodiments to detail this application.

[0044] The preferred embodiments of the present invention will be elaborated in detail below with reference to the drawings.

[0045] Embodiment 1: Refer to Figure 1 and Figure 2 This embodiment will be described in detail. An experimental device for verifying the sealing performance of a high-temperature wire includes a rectangular container 1, a temperature sensor 2, a pressure sensor 3, a temperature-controlled electric heating rod 4, an adjusting rod 5, a cover plate 6, a seal 7, a second seal pressing block 8, a first seal pressing block 13, a high-temperature alloy spring 9, a seal baffle 10, an air inlet 11, an exhaust port 12, and a slotted wall plate 14;

[0046] The cover plate 6 is installed on the right side of the rectangular container 1, and the seal baffle 10 is welded inside the rectangular container 1, dividing the rectangular container 1 into a left chamber and a right chamber. The air inlet 11 is arranged on the left side of the rectangular container 1, connected to a valve and an air compressor to provide pressure for the experiment and communicate with the left chamber. The exhaust port 12 is arranged on the right side of the cover plate 6 and communicates with the right chamber;

[0047] A temperature sensor 2, a pressure sensor 3, and a temperature-controlled electric heating rod 4 are inserted into the rectangular container 1, and the detection ends of the temperature sensor 2, the detection end of the pressure sensor 3, and the heating end of the temperature-controlled electric heating rod 4 are all located in the left chamber, for measuring temperature and pressure and providing temperature.

[0048] The slotted wall plate 14 is welded inside the rectangular container 1 and is located in the right chamber. The seal 7 is embedded between the sealing baffle 10 and the slotted wall plate 14. The second sealing press block 8 is installed on the seal 7. The adjusting rod 5 passes through the upper wall plate of the rectangular container 1 and is connected to the first sealing press block 13. The two ends of the superalloy spring 9 are respectively embedded in the first sealing press block 13 and the second sealing press block 8 to make the elastic force distribution average.

[0049] A gap is left between the lower end of the sealing baffle 10 and the rectangular container 1, and the height of the gap is 2 mm.

[0050] A gap is left between the lower end of the slotted wall plate 14 and the rectangular container 1, and the height of the gap is 2 mm.

[0051] More specifically: A chute is provided on the right side of the sealing baffle 10, and the first sealing press block 13 and the second sealing press block 8 are installed in the chute.

[0052] More specifically: The first sealing press block 13 and the second sealing press block 8 are both milled with 8 circular grooves with a diameter of 12 mm and a depth of 1 mm, and eight superalloy springs 9 are placed in the circular grooves.

[0053] More specifically: The material of the superalloy spring 9 is GH4145, the wire diameter of the spring is 2 mm, the mean diameter of the spring is 10 mm, the number of turns is 14.5, and the eight springs can provide a maximum pressing force of 2000 N.

[0054] More specifically: The internal volume of the rectangular container 1 is 180 mm × 180 mm × 115 mm.

[0055] The length of the seal 7 is 20 mm, the width is 180 mm, and the height is 20 mm.

[0056] More specifically: The adjusting rod 5 is used to adjust the elastic force of the superalloy spring 9. The seal 7 is provided with a pressing force by the superalloy spring 9. By changing the adjusting rod 5, the length of the superalloy spring 9 is controlled to adjust the pressing force.

[0057] More specifically: After closing the valve between the air compressor and the air inlet 11 of the experimental equipment, the temperature is raised by the temperature-controlled electric heating rod 4, and the pressure after heating is calculated by the pressure provided by the air compressor and the ideal gas equation PV = nRT.

[0058] Example 2: An experimental method for verifying the sealing performance of a high-temperature wire, which is realized relying on the experimental equipment for verifying the sealing performance of a high-temperature wire described in Example 1. The operation process is as follows:

[0059] Step 1: Verify the sealing performance of the seal 7 at different temperatures;

[0060] Control the pressure in the rectangular container 1 to be 1.2 MPa and the pressing force to be 300 N. Measure the pressure drop in the rectangular container 1 per unit time at temperatures of 200 °C, 250 °C, 300 °C, 350 °C, 400 °C, 450 °C, and 500 °C respectively, so as to judge the sealing performance of the seal 7 at different temperatures;

[0061] Step 2: Verify the sealing performance of the seal 7 under different pressing forces;

[0062] Control the initial temperature in the rectangular container 1 to be 500 °C and the pressure to be 1.2 MPa. Close the valve of the air inlet 11, keep the temperature unchanged, change the length of the adjusting rod 5, and measure the pressure drop in the rectangular container 1 per unit time at pressing forces of 100 N, 150 N, 200 N, 250 N, 300 N, 350 N, 400 N, 450 N, 500 N, 600 N, 700 N, 800 N, 900 N, and 1000 N respectively, so as to judge the sealing performance of the seal 7 under different pressing forces;

[0063] Step 3: Verify the sealing performance of the seal 7 under different pressures;

[0064] Control the initial temperature in the rectangular container 1 to be 500 °C and the pressing force to be 400 N. Measure the pressure drop in the rectangular container 1 per unit time at pressures of 0.6 MPa, 0.8 MPa, 1.0 MPa, 1.2 MPa, 1.4 MPa, 1.6 MPa, 1.8 MPa, and 2.0 MPa respectively, so as to judge the sealing performance of the seal 7 under different pressures;

[0065] Step 4: The inside of the seal 7 is filled with flexible graphite packing. According to the experimental data in Steps 1 to 3, obtain the temperature coefficient curve, and obtain the functional relationship between the clearance height between the flexible graphite packing and the seal baffle 10 and the pressing force. Its calculation formula is:

[0066] ;

[0067] where is the clearance height between the seal 7 and the seal baffle 10;

[0068] F is the pressing force;

[0069] Both k and n are constants, and n is a positive number.

[0070] More specifically, the leakage of the experimental equipment is mainly caused by the gap between the flexible graphite packing and the sealing baffle 10, which belongs to clearance sealing. Through the analysis of the leakage cause and mechanism, the leakage amount under comprehensive factors is obtained. Calculation formula:

[0071] ;

[0072] Wherein, is the temperature coefficient;

[0073] is the clearance height between the seal 7 and the sealing baffle 10;

[0074] L is the sealing length of the seal 7;

[0075] is the sealing width of the seal 7;

[0076] is the pressure difference of the sealing medium at both ends of the seal 7;

[0077] is the hydrodynamic viscosity of the sealing medium.

[0078] Through the pressure drop per unit time and the known container volume, the leakage amount of the gas in the container per unit time can be judged. The leakage amount is qualified when it is between 10 - 100 sccm, excellent when it is within 10 sccm, and unqualified when it is outside 100 sccm.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent substitution on some or all of the technical features; as long as there is no structural conflict, the various features in the specific embodiments disclosed in this application can be combined with each other in any way, and it will not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the present invention.

[0080] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An experimental method for verifying the sealing performance of high-temperature wires, which is realized relying on an experimental device for verifying the sealing performance of high-temperature wires. The experimental device for verifying the sealing performance of high-temperature wires includes a rectangular container (1), a temperature sensor (2), a pressure sensor (3), a temperature-controlled electric heating rod (4), an adjusting rod (5), a cover plate (6), a sealing member (7), a second sealing block (8), a first sealing block (13), a high-temperature alloy spring (9), a sealing baffle (10), an air inlet (11), an exhaust port (12), and a slotted wall plate (14); The cover plate (6) is installed on the right side of the rectangular container (1), and the sealing baffle (10) is welded inside the rectangular container (1), dividing the rectangular container (1) into a left chamber and a right chamber. The air inlet (11) is arranged on the left side of the rectangular container (1) and communicates with the left chamber. The exhaust port (12) is arranged on the right side of the cover plate (6) and communicates with the right chamber; The rectangular container (1) is inserted with a temperature sensor (2), a pressure sensor (3), and a temperature-controlled electric heating rod (4), and the detection end of the temperature sensor (2), the detection end of the pressure sensor (3), and the heating end of the temperature-controlled electric heating rod (4) are all located in the left chamber; The slotted wall plate (14) is welded inside the rectangular container (1) and is located in the right chamber. The sealing member (7) is embedded between the sealing baffle (10) and the slotted wall plate (14). The second sealing block (8) is installed on the sealing member (7). The adjusting rod (5) passes through the upper wall plate of the rectangular container (1) and is connected to the first sealing block (13). The two ends of the high-temperature alloy spring (9) are respectively embedded in the first sealing block (13) and the second sealing block (8); There is a gap between the lower end of the sealing baffle (10) and the rectangular container (1), and the height of the gap is 2 mm; There is a gap between the lower end of the slotted wall plate (14) and the rectangular container (1), and the height of the gap is 2 mm; It is characterized in that: The operation process is as follows: Step 1: Verify the sealing performance of the sealing member (7) at different temperatures; Control the pressure in the rectangular container (1) to be 1.2 MPa and the compaction force to be 300 N. Measure the pressure drop in the rectangular container (1) per unit time at temperatures of 200 °C, 250 °C, 300 °C, 350 °C, 400 °C, 450 °C, and 500 °C respectively, so as to judge the sealing performance of the sealing member (7) at different temperatures; Step 2: Verify the sealing performance of the sealing member (7) under different compaction forces; Control the initial temperature in the rectangular container (1) to be 500 °C and the pressure to be 1.2 MPa. Close the valve of the air inlet (11), keep the temperature unchanged, change the length of the adjusting rod (5), and measure the pressure drop in the rectangular container (1) per unit time when the compaction forces are 100 N, 150 N, 200 N, 250 N, 300 N, 350 N, 400 N, 450 N, 500 N, 600 N, 700 N, 800 N, 900 N, and 1000 N respectively, so as to judge the sealing performance of the sealing member (7) under different compaction forces; Step 3: Verify the sealing performance of the sealing member (7) under different pressures; Control the initial temperature in the rectangular container (1) to be 500 °C and the pressing force to be 400 N. Measure the pressure drop in the rectangular container (1) per unit time when the pressures are 0.6 MPa, 0.8 MPa, 1.0 MPa, 1.2 MPa, 1.4 MPa, 1.6 MPa, 1.8 MPa, and 2.0 MPa respectively, so as to judge the sealing performance of the seal (7) under different pressures; Step 4: The inside of the seal (7) is filled with flexible graphite packing. According to the experimental data in Steps 1 to 3, obtain the temperature coefficient curve and the functional relationship between the gap height of the flexible graphite packing and the seal baffle (10). The calculation formula is: ； where h is the gap height between the seal (7) and the seal baffle (10); F is the pressing force; Both k and n are constants, and n is a positive number; Furthermore, calculate the leakage amount generated by the gap between the flexible graphite packing and the seal baffle (10).

2. The experimental method for verifying the sealing performance of high-temperature wires according to claim 1, wherein: A chute is provided on the right side of the seal baffle (10), and the first seal pressing block (13) and the second seal pressing block (8) are installed in the chute.

3. The experimental method for verifying the sealing performance of a high-temperature wire according to claim 1, wherein: Both the first seal pressing block (13) and the second seal pressing block (8) are milled with 8 circular grooves with a diameter of 12 mm and a depth of 1 mm, and eight high-temperature alloy springs (9) are placed in the circular grooves.

4. An experimental method for verifying the sealing performance of high-temperature wires according to claim 1, characterized in that: The material of the high-temperature alloy spring (9) is GH4145, the wire diameter of the spring is 2 mm, the mean diameter of the spring is 10 mm, and the number of turns is 14.5.

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