Experimental equipment and experimental method for verifying sealing performance of high-temperature wire

Abstract

The invention discloses experimental equipment and an experimental method for verifying high-temperature line sealing performance, and belongs to the technical field of aviation aerodynamic force wind tunnel line sealing performance experimental evaluation. The problem that in the prior art, sealing evaluation cannot be carried out on the linear sealing structure under different temperatures, different pressures and different pressing forces is solved. The technical key points are as follows: the sealing performance of the sealing element at different temperatures, the sealing performance of the sealing element under different pressing forces and the sealing performance of the sealing element under different pressures are respectively verified, a temperature coefficient curve is obtained according to experimental data, and a function relationship between the gap height of the flexible graphite filler and the sealing baffle plate and the pressing forces is obtained. By verifying the sealing capacity of the sealing structure and accurately measuring the leakage rates under different working conditions, the stability and controllability of a flow field in a wind tunnel can be ensured, it is ensured that experimental data truly reflect the physical law of hypersonic flow, and a reliable basis is provided for aircraft design and related theoretical research.

Description

Technical Field

[0001] The invention relates to the technical field of aviation aerodynamic wind tunnel line sealing performance experimental evaluation, in particular to an experimental device and an experimental method for verifying the sealing performance of a high-temperature line. Background Art

[0002] During the hypersonic wind tunnel experiment, the sealing structure between the flexible wall nozzle and the side wall faces many challenges. When the airflow passes through the nozzle, a lot of heat is generated, causing the temperature of the flexible wall nozzle and the side wall to rise sharply. Generally speaking, the temperature in the hypersonic wind tunnel experiment may reach 500℃ or even higher. Under such high temperatures, ordinary sealing materials will age, deform or even melt rapidly, resulting in a decrease in sealing performance. At the same time, the pressure inside the wind tunnel will fluctuate violently due to factors such as unstable airflow. The rapid change in pressure will cause the sealing structure to bear alternating stress, which is easy to cause fatigue damage to the seal and reduce the sealing effect. Large pressure changes increase 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: high-temperature sealing performance test device for refractory sealing materials, which can accurately evaluate the sealing effect of the sealing materials used in high-temperature lines at high temperatures, provide strong support for the selection and improvement of materials, and can effectively evaluate the sealing reliability of high-temperature lines under extreme conditions; hot air aging test chamber equipment, which has a relatively simple structure and an intuitive operating interface. Operators can get started after simple training, reducing labor costs and operating difficulties.

[0004] Existing verification sealing devices still have many limitations. The simulated working conditions are single and can only simulate high-temperature environments, but cannot simulate other complex working conditions such as high pressure at the same time; the test time is long, resulting in low test efficiency and an inability to obtain test results quickly; it is mainly used for static testing and cannot simulate the dynamic movement of high-temperature wires in actual work, and has limited ability to evaluate dynamic sealing performance.

[0005] Therefore, it is urgent to propose an experimental device and an experimental method for verifying the high-temperature wire sealing performance, so as to solve the problem in the prior art that the wire sealing structure cannot be evaluated for sealing under different temperatures, different pressures, and different compression forces. Summary of the invention

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

[0007] To achieve the above object, the present invention adopts the following technical solution: Solution 1: An experimental device for verifying the sealing performance of a high-temperature line, comprising a rectangular container, a temperature sensor, a pressure sensor, a temperature-controllable electric heating rod, an adjusting rod, a cover plate, a seal, a second sealing block, a first sealing block, a high-temperature alloy spring, a sealing baffle, an air inlet, an exhaust port, and a slotted wall plate; The cover plate is installed on the right side of the rectangular container, the sealing baffle is welded inside the rectangular container, and the rectangular container is divided 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; The rectangular container is equipped with a temperature sensor, a pressure sensor, and a temperature-controllable electric heating rod, and the detection end of the temperature sensor, the detection end of the pressure sensor, and the heating end of the temperature-controllable electric heating rod are all located in the left chamber; The slit wall plate is welded in the rectangular container and is located in the right chamber. The seal is embedded between the sealing baffle and the slit wall plate. The second sealing block is installed on the seal. The adjustment rod passes through the upper wall plate of the rectangular container and is connected to the first sealing block. Both ends of the high-temperature alloy spring are respectively embedded in the first sealing block and the second sealing block. There is a gap between the lower end of the sealing baffle and the rectangular container, and the gap height is 2mm; A gap is left between the lower end of the slit wall panel and the rectangular container, and the gap height is 2 mm.

[0008] Furthermore: a slide groove is arranged on the right side of the sealing baffle, and the first sealing pressing block and the second sealing pressing block are installed in the slide groove.

[0009] Furthermore: 8 circular grooves with a diameter of 12 mm and a depth of 1 mm are milled out of the first sealing pressing block and the second sealing pressing block, and eight high-temperature alloy springs are placed in the circular grooves.

[0010] Furthermore: the high temperature alloy spring material is GH4145, the spring wire diameter is 2 mm, the spring middle diameter is 10 mm, and the number of turns is 14.5.

[0011] Further: the internal volume of the rectangular container is 180mm×180mm×115mm; The sealing member has a length of 20 mm, a width of 180 mm and a height of 20 mm.

[0012] Solution 2: An experimental method for verifying the sealing performance of a high-temperature line, which is implemented based on an experimental device for verifying the sealing performance of a high-temperature line described in Solution 1, and the operation process is as follows: Step 1: Verify the sealing performance of the seal at different temperatures; The pressure in the rectangular container is controlled to be 1.2MPa and the pressing force is 300N. The pressure drop in the rectangular container per unit time is measured at temperatures of 200℃, 250℃, 300℃, 350℃, 400℃, 450℃ and 500℃, so as to judge the sealing performance of the seal at different temperatures. Step 2: Verify the sealing performance of the seal under different compression forces; The initial temperature in the rectangular container is controlled to be 500℃, the pressure is 1.2MPa, the valve of the air inlet is closed, the temperature is kept constant, the length of the adjusting rod is changed, and the pressure drop in the rectangular container per unit time is measured when the pressing force is 100N, 150N, 200N, 250N, 300N, 350N, 400N, 450N, 500N, 600N, 700N, 800N, 900N, and 1000N, so as to judge the sealing performance of the seal under different pressing forces; Step 3: Verify the sealing performance of the seal under different pressures; The initial temperature in the rectangular container is controlled to be 500°C and the pressing force is 400N. The pressure drop in the rectangular container per unit time is measured when the pressure is 0.6MPa, 0.8MPa, 1.0MPa, 1.2MPa, 1.4MPa, 1.6MPa, 1.8MPa, and 2.0MPa, respectively, so as to judge the sealing performance of the seal under different pressures. Step 4: The interior of the seal is filled with flexible graphite filler. According to the experimental data of steps 1 to 3, the temperature coefficient curve is obtained, and the functional relationship between the gap height and the pressing force between the flexible graphite filler and the sealing baffle is obtained. The calculation formula is: ;

[0013] in, is the gap height between the seal and the sealing baffle; F is the pressing force; Both k and n are constants, and n is a positive number.

[0014] The beneficial effects of the present invention are: 1. The present invention uses multi-operating condition evaluation to more accurately grasp the performance characteristics and applicable scope of the wire sealing structure, and can fully understand its sealing ability under various complex operating conditions.

[0015] 2. The present invention can ensure the stability and controllability of the flow field inside the wind tunnel by verifying the sealing ability of the sealing structure and accurately measuring the leakage under different working conditions, 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.

[0016] 3. The present invention provides an important reference for the design and optimization of wind tunnels. Engineers can improve the design of sealing structures in a targeted manner, select more suitable sealing materials and sealing methods, improve the sealing performance of wind tunnels, reduce energy losses, and reduce operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a cross-sectional view of the experimental equipment in the present invention; Figure 2 It is a top view of the experimental equipment in the present invention.

[0018] In the figure: 1-rectangular container, 2-temperature sensor, 3-pressure sensor, 4-temperature-controllable electric heating rod, 5-adjusting rod, 6-cover plate, 7-seal, 8-second sealing block, 9-high-temperature alloy spring, 10-sealing baffle, 11-air inlet, 12-exhaust port, 13-first sealing block, 14-slit wall panel. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0020] 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 are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0021] In the present application, the directions or positional relationships indicated by the terms "upper", "lower", "inner", "middle", "outer", "front", "back", etc. are based on the directions or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction.

[0022] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency 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 specific circumstances.

[0023] In addition, the terms "disposed", "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 a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection 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 specific circumstances.

[0024] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0025] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0026] Example 1: Reference Figure 1 and Figure 2 The present embodiment is described in detail, an experimental device for verifying the sealing performance of a high temperature line includes a rectangular container 1, a temperature sensor 2, a pressure sensor 3, a temperature-controllable 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 to divide 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 the valve and the air compressor to provide pressure for the experiment, and communicated with the left chamber. The exhaust port 12 is arranged on the right side of the cover plate 6 and communicated with the right chamber. The rectangular container 1 is plugged with a temperature sensor 2, a pressure sensor 3, and a temperature-controllable 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-controllable electric heating rod 4 are all located in the left chamber, for measuring temperature and pressure and providing temperature; The slotted wall plate 14 is welded in 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 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 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, so that the elastic force is evenly distributed. There is a gap between the lower end of the sealing baffle 10 and the rectangular container 1, and the gap height is 2mm; There is a gap between the lower end of the slotted wall plate 14 and the rectangular container 1, and the gap height is 2 mm.

[0027] More specifically: a slide groove is provided on the right side of the sealing baffle 10, and the first sealing pressing block 13 and the second sealing pressing block 8 are installed in the slide groove.

[0028] More specifically: 8 circular grooves with a diameter of 12 mm and a depth of 1 mm are milled out of the first sealing pressing block 13 and the second sealing pressing block 8, and eight high-temperature alloy springs 9 are placed in the circular grooves.

[0029] More specifically: the material of the high temperature alloy spring 9 is GH4145, the spring wire diameter is 2 mm, the spring middle diameter is 10 mm, the number of turns is 14.5, and the eight springs can provide a maximum clamping force of 2000N.

[0030] More specifically: the internal volume of the rectangular container 1 is 180mm×180mm×115mm; The sealing member 7 has a length of 20 mm, a width of 180 mm and a height of 20 mm.

[0031] More specifically: the adjusting rod 5 is used to adjust the elastic force of the high-temperature alloy spring 9. The sealing member 7 is provided with a clamping force by the high-temperature alloy spring 9. By changing the adjusting rod 5, the length of the high-temperature alloy spring 9 is controlled to adjust the clamping force.

[0032] More specifically: after the experimental equipment closes the valve between the air compressor and the air inlet 11, the temperature is increased by using the temperature-controllable 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.

[0033] Embodiment 2: An experimental method for verifying the sealing performance of a high-temperature line in this embodiment is implemented by relying on an experimental device for verifying the sealing performance of a high-temperature line described in Embodiment 1. The operation process is as follows: Step 1: Verify the sealing performance of the sealing member 7 at different temperatures; The pressure in the rectangular container 1 is controlled to be 1.2 MPa and the pressing force is 300 N. The pressure drop in the rectangular container 1 per unit time is measured at temperatures of 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, and 500°C, respectively, so as to determine the sealing performance of the sealing member 7 at different temperatures. Step 2: Verify the sealing performance of the sealing member 7 under different pressing forces; The initial temperature in the rectangular container 1 is controlled to be 500°C and the pressure is 1.2 MPa. The valve of the air inlet 11 is closed to keep the temperature constant. The length of the adjusting rod 5 is changed. The pressure drop in the rectangular container 1 per unit time is measured when the pressing force is 100N, 150N, 200N, 250N, 300N, 350N, 400N, 450N, 500N, 600N, 700N, 800N, 900N and 1000N, so as to judge the sealing performance of the sealing member 7 under different pressing forces. Step 3: Verify the sealing performance of the sealing element 7 under different pressures; The initial temperature in the rectangular container 1 is controlled to be 500°C and the pressing force is 400N. The pressure drop in the rectangular container 1 per unit time is measured when the pressure is 0.6MPa, 0.8MPa, 1.0MPa, 1.2MPa, 1.4MPa, 1.6MPa, 1.8MPa, and 2.0MPa, respectively, so as to judge the sealing performance of the sealing member 7 under different pressures. Step 4: The interior of the sealing member 7 is filled with a flexible graphite filler. Based on the experimental data of steps 1 to 3, a temperature coefficient curve is obtained to obtain a functional relationship between the gap height and the pressing force between the flexible graphite filler and the sealing baffle 10. The calculation formula is: ;

[0034] in, is the gap height between the sealing member 7 and the sealing baffle 10; F is the pressing force; Both k and n are constants, and n is a positive number.

[0035] More specifically: the leakage of the experimental equipment is mainly caused by the gap between the flexible graphite filler and the sealing baffle 10, which belongs to the gap seal. By analyzing the leakage cause and mechanism, the leakage amount under comprehensive factors is obtained. Calculation formula: ;

[0036] in, is the temperature coefficient; is the gap height between the sealing member 7 and the sealing baffle 10; L is the sealing length of the seal 7; is the sealing width of the seal 7; is the sealing medium pressure difference at both ends of the sealing element 7; is the fluid dynamic viscosity of the sealing medium.

[0037] 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 determined. A leakage amount of 10-100sccm is qualified, within 10sccm is excellent, and outside 100sccm is unqualified.

[0038] 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 aforementioned embodiments, the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. As long as there is no structural conflict, the various features in the specific implementation methods disclosed in this application can be combined with each other in any way, and the essence of the corresponding technical solutions will not deviate from the scope of the technical solutions of the present invention.

[0039] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An experimental device for verifying the sealing performance of a high temperature line, characterized in that: It comprises a rectangular container (1), a temperature sensor (2), a pressure sensor (3), a temperature-controllable 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 air outlet (12), and a slotted wall plate (14); The cover plate (6) is installed on the right side of the rectangular container (1), the sealing baffle (10) is welded inside the rectangular container (1), and the rectangular container (1) is divided into a left chamber and a right chamber, the air inlet (11) is arranged on the left side of the rectangular container (1) and is in communication with the left chamber, and the air outlet (12) is arranged on the right side of the cover plate (6) and is in communication with the right chamber; The rectangular container (1) is installed with a temperature sensor (2), a pressure sensor (3), and a temperature-controllable 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-controllable electric heating rod (4) are all located in the left chamber; The slotted wall plate (14) is welded in 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 mounted 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). A gap is left between the lower end of the sealing baffle (10) and the rectangular container (1), and the gap height is 2 mm; A gap is left between the lower end of the slotted wall plate (14) and the rectangular container (1), and the gap height is 2 mm.

2. The experimental equipment for verifying the sealing performance of a high temperature line according to claim 1, characterized in that: A slide groove is provided on the right side of the sealing baffle (10), and the first sealing pressing block (13) and the second sealing pressing block (8) are installed in the slide groove.

3. The experimental equipment for verifying the sealing performance of a high temperature line according to claim 1, characterized in that: The first sealing pressing block (13) and the second sealing pressing block (8) are both milled with eight 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. The experimental equipment for verifying the sealing performance of a high temperature line according to claim 1, characterized in that: The high temperature alloy spring (9) is made of GH4145, has a spring wire diameter of 2 mm, a spring center diameter of 10 mm, and a number of turns of 14.

5.

5. An experimental method for verifying the sealing performance of a high-temperature line, which is implemented by relying on the experimental equipment for verifying the sealing performance of a high-temperature line according to claim 1, characterized in that: The operation process is: Step 1: verifying the sealing performance of the sealing member (7) at different temperatures; The pressure in the rectangular container (1) is controlled to be 1.2 MPa and the pressing force is controlled to be 300 N. The pressure drop in the rectangular container (1) per unit time is measured at temperatures of 200° C., 250° C., 300° C., 350° C., 400° C., 450° C., and 500° C., thereby determining the sealing performance of the sealing member (7) at different temperatures. Step 2: verifying the sealing performance of the sealing member (7) under different pressing forces; The initial temperature in the rectangular container (1) is controlled to be 500°C and the pressure is controlled to be 1.2 MPa. The valve of the air inlet (11) is closed to keep the temperature constant. The length of the adjusting rod (5) is changed. The pressure drop in the rectangular container (1) per unit time is measured when the pressing force is 100N, 150N, 200N, 250N, 300N, 350N, 400N, 450N, 500N, 600N, 700N, 800N, 900N and 1000N, respectively, so as to judge the sealing performance of the sealing member (7) under different pressing forces. Step 3: Verify the sealing performance of the sealing element (7) under different pressures; The initial temperature in the rectangular container (1) is controlled to be 500° C. and the pressing force is controlled to be 400 N. The pressure drop in the rectangular container (1) per unit time is measured when the pressure is 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 determine the sealing performance of the sealing member (7) under different pressures. Step 4: The interior of the sealing member (7) is filled with a flexible graphite filler. Based on the experimental data of steps 1 to 3, a temperature coefficient curve is obtained to obtain a functional relationship between the gap height and the pressing force between the flexible graphite filler and the sealing baffle (10). The calculation formula is: ； in, is the gap height between the sealing element (7) and the sealing baffle (10); F is the pressing force; Both k and n are constants, and n is a positive number.

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