A non-contact seal air pressure loading test device for the inner ring of a turbine guide vane

Abstract

This application belongs to the field of aeroengines. A non-contact sealing air pressure loading test device for the inner ring of a turbine guide vane includes: an upper sealing plate having a sealing groove into which a first arm and a third arm can be inserted. The groove wall of the sealing groove is of a labyrinth type, and the bottom of the sealing groove has an elastic colloid; a lower sealing plate, which is sealed and fixedly connected to a second arm and also has the sealing groove at the fourth arm. The fourth arm is inserted and connected to the sealing groove; a connecting rod. A spacer ring is sleeved in the middle of the connecting rod, and one end of the upper sealing plate and one end of the lower sealing plate are respectively sleeved at both ends to implement adjustable sealing. The labyrinth type groove and the adjusting bolt can be used to adjust the sealing effect of the labyrinth type groove, thereby adjusting the airtight effect of the inner ring of the guide vane, adjusting the air pressure in each chamber, so as to achieve better experimental results and realize various test objectives.

Description

Technical Field

[0001] This application belongs to the field of aeroengines, and particularly relates to a non-contact sealing air pressure loading test device for the inner ring of a turbine guide vane. Background Technique

[0002] The turbine guide vane of an aeroengine is an annular structure composed of inner and outer rings and a group of guide vanes. Its function is to convert part of the thermal energy of the air flow into kinetic energy and flow out in a certain direction. Since the inner ring of the turbine guide vane faces a complex air pressure distribution state during operation, in order to ensure the safety of the inner ring of the guide vane during operation, it is necessary to conduct a pressure strength assessment test on it; at the same time, since the guide vanes are installed on the inner ring of the guide vane, the deformation of the inner ring of the guide vane will cause a change in the working state of the guide vanes, and the deformation of the inner ring of the guide vane also affects its sealing problem with the rotor. Therefore, the deformation of the inner ring of the guide vane under the working state is also the key object of assessment.

[0003] The simplified air pressure distribution diagram of the inner ring of the turbine guide vane is shown in Figure 1 , and the magnitude of its air pressure is generally: chamber a > chamber b > chamber c. When applying air pressure to these three chambers, the existing air pressure loading test device for the inner ring of the guide vane is shown in Figure 2 , the bottom plate 2, the top plate 5 and the inner ring 7 of the guide vane form two closed cavities. The contact seal of the cavity is carried out between the bottom plate 2, the top plate 5 and the inner ring of the guide vane through the O-ring 1. The installation distance between the top plate 5 and the bottom plate 2 is determined by the spacer ring 3 and fixed by the connecting rod 4. The air pressure loading unit 6 is used to apply air pressure load. During the test, chamber c is communicated with the atmosphere. In order to keep the pressure difference unchanged, the original air pressure a becomes a - c, and the original air pressure b becomes b - c, so as to complete the loading of three air pressures with two sealed cavities. The existing test device seals the cavity in a contact sealing manner, that is, a U-shaped groove is machined on the side of the test device, and an O-ring rubber seal is installed, so that the inner ring of the guide vane is in interference fit with the O-ring, and the O-ring rubber is extruded and deformed to fit closely with the inner ring of the guide vane to achieve the sealing effect.

[0004] The existing test device seals the cavity in a contact sealing manner, that is, a U-shaped groove is machined on the side of the test device, and an O-ring rubber seal is installed, so that the inner ring of the guide vane is in interference fit with the O-ring, and the O-ring rubber is extruded and deformed to fit closely with the inner ring of the guide vane to achieve the sealing effect.

[0005] Since the contact sealing form between the inner ring of the guide vane and the O-ring is an interference fit, there is a large frictional resistance between the O-ring and the inner ring of the guide vane. When using the existing test device to apply air pressure to the inner ring of the guide vane, compared with its actual working state, the frictional resistance has a certain influence on the stress distribution and deformation of the inner ring of the guide vane, which is not conducive to the assessment of the safety and deformation of the inner ring of the guide vane. Summary of the Invention

[0006] To solve the above problems, the present application provides a non-contact sealing air pressure loading test device for the inner ring of a turbine guide vane. After the device is connected to the inner ring of the guide vane, a pressurization test is carried out. The inner ring of the guide vane has a first support arm, a second support arm, a third support arm and a fourth support arm. It is characterized in that the non-contact sealing air pressure loading test device includes:

[0007] An upper sealing plate having a sealing groove into which the first support arm and the third support arm can be inserted. The groove wall of the sealing groove is of a labyrinth type, and the bottom of the sealing groove has an elastic colloid;

[0008] A lower sealing plate, which is sealed and fixedly connected to the second support arm and also has the sealing groove at the fourth support arm. The fourth support arm is inserted and connected to the sealing groove;

[0009] A connecting rod. A spacer ring is sleeved in the middle of the connecting rod, and one end of the upper sealing plate and one end of the lower sealing plate are respectively sleeved at both ends;

[0010] An air adjusting screw, which is connected to the other end of the upper sealing plate and the other end of the lower sealing plate. The air adjusting screw has a threaded section and a labyrinth section. The air adjusting screw changes the contact area between the labyrinth section and the sealing plate or the sealing plates by screwing in and out.

[0011] Preferably, an adjusting bolt is installed on the colloid. The adjusting bolt changes the position of the colloid by rotation.

[0012] Preferably, a honeycomb ring is installed at the sealing groove of the first support arm.

[0013] Preferably, an adjusting ring is provided between the adjusting bolt and the colloid. The adjusting ring is threadedly connected to the adjusting bolt and fixedly connected to the colloid.

[0014] Preferably, the minimum distance between the labyrinth teeth of the sealing groove and the upper sealing plate or the lower sealing plate gradually decreases from the outer end to the inner end of the sealing groove. In addition, to improve the sealing effect, the minimum distance between the upper sealing plate or the lower sealing plate gradually increases from the outer end to the inner end of the sealing groove.

[0015] Preferably, the minimum distance between the labyrinth teeth of the sealing groove and the upper sealing plate or the lower sealing plate is not greater than one-tenth of the width of the sealing groove.

[0016] Preferably, the honeycomb ring is connected with a support plate, and the support plate is sleeved on the connecting rod.

[0017] Preferably, the labyrinth section of the air adjusting screw contacts the upper sealing plate and is connected to the atmosphere, and the threaded section is connected to the lower sealing plate.

[0018] Preferably, a sealing strip is provided at the connection between the labyrinth section and the atmosphere.

[0019] Preferably, the material of the colloid includes 10% - 20% of resin glue.

[0020] The advantages of this application include:

[0021] It changes the contact sealing form between the existing test device and the inner ring of the guide vane, reduces the frictional resistance at the contact position, and reduces the influence of the frictional resistance on the stress and deformation state of the inner ring of the guide vane.

[0022] Implement adjustable sealing. The labyrinth-type groove and the adjusting bolt can be used to adjust the sealing effect of the labyrinth-type groove, thereby adjusting the airtight effect of the inner ring of the guide vane, adjusting the air pressure in each chamber, so as to achieve better experimental results and realize various test objectives. Brief Description of the Drawings

[0023] Figure 1 It is a schematic structural diagram of the inner ring of the guide vane;

[0024] Figure 2 It is a traditional pneumatic loading test device for the inner ring of a turbine guide vane;

[0025] Figure 3 Tooling structure diagram of the non-contact sealing pneumatic loading test device for the inner ring of the guide vane in a preferred embodiment of this application;

[0026] Figure 4 Schematic diagram of the non-contact sealing pneumatic loading test device for the inner ring of the guide vane in a preferred embodiment of this application;

[0027] Figure 5 Detail drawing of the labyrinth seal structure between the inner ring of the guide vane and the sealing plate;

[0028] Figure 6 Schematic diagram of the seal groove structure in a preferred embodiment of this application;

[0029] Figure 7 Detail drawing of the connection between the upper sealing plate, the lower sealing plate and the air adjusting screw;

[0030] Figure 8 Detail drawing of the installation position of the honeycomb ring;

[0031] Among them, 21 - the first arm, 22 - the second arm, 23 - the third arm, 24 - the fourth arm, 31 - O-ring; 32 - the bottom plate; 33 - the spacer ring; 34 - the connecting rod; 35 - the top plate; 36 - the pneumatic loading unit; 37 - the inner ring of the guide vane; 1 - the lower sealing plate; 2 - the inner ring of the guide vane; 3 - the fixed end; 4 - the spacer ring; 5 - the honeycomb ring; 6 - the connecting rod; 7 - the colloid and the adjusting ring; 8 - the adjusting bolt; 9 - the pneumatic loading unit; 10 - the upper sealing plate; 11 - the air adjusting screw, a-a chamber, b-b chamber, c-c chamber. Detailed Description of the Invention

[0032] To make the purpose, technical solutions, and advantages of the implementation of this application clearer, the following will describe the technical solutions in the implementation of this application in more detail in combination with the accompanying drawings in the implementation of this application. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The described implementation is part of the implementations of this application, rather than all of the implementations. The implementations described below by referring to the accompanying drawings are exemplary and are intended to explain this application, and should not be construed as a limitation to this application. Based on the implementations in this application, all other implementations obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by this application. The following will explain the implementation of this application in detail in combination with the accompanying drawings.

[0033] The non-contact seal air pressure loading test device for the inner ring of the guide vane is as Figure 3 , Figure 4 shown. The test tooling mainly consists of an upper seal plate, a lower seal plate, a spacer ring, a honeycomb ring, adjusting bolts, a colloid, and an adjusting ring. When installed as Figure 4 shown, the lower side of the inner ring 2 of the guide vane is fixed on the lower seal plate 1 through the fixed end 3, the upper seal plate 10 is installed on the upper side of the inner ring 2 of the guide vane, the installation distance between the outer sides of the upper seal plate 10 and the lower seal plate 1 is determined by the spacer ring 4 and fixed through the connecting rod 6, the inner sides of the upper seal plate 10 and the lower seal plate 1 are connected through the air adjusting screw 11, the honeycomb ring 5 is installed in the middle of the spacer ring 4 for decelerating the air flow; and near the labyrinth seal structure with comb teeth on the lower seal plate 1 and the upper seal plate 10, the size of the air flow channel can be adjusted by installing the colloid, the adjusting ring 7, and the adjusting bolts 8; cavities a, b, and c are formed between the inner ring of the guide vane and the test tooling, and the air pressure loading unit 9 is used to apply air pressure loads to the 3 cavities.

[0034] According to the working load-bearing state of the inner ring of the guide vane, the contact seal form of the U-shaped groove and the O-ring can still be adopted at the contact position between the test tooling near the fixed end 3 and the inner ring of the guide vane, while the contact positions on the left and right sides between the inner ring of the guide vane and the upper seal plate and the lower seal plate are designed as non-contact labyrinth seal structures with comb teeth. The minimum distance between the comb teeth of the seal groove and the upper seal plate or the lower seal plate gradually decreases from the outer end to the inner end of the seal groove. The detailed drawing is as Figure 5 shown.

[0035] According to aerodynamics knowledge, the air leakage amount m depends on the air leakage area F, the pressure difference Δp (determining the air leakage speed) at both ends of the air leakage, and the air density ρ, that is:

[0036]

[0037] Therefore, in order to improve the air sealing effect, while reducing the air leakage area, the pressure difference Δp should also be reduced.Figure 5 The labyrinth seal structure with comb teeth shown in the figure consists of multiple cavities. In each cavity, due to vortex and impact with the wall surface, the gas flow velocity is greatly reduced. When the gas flows from one cavity to another through the gap, due to gas expansion, the pressure in the adjacent cavity decreases. Although the total pressure difference on both sides of the labyrinth seal structure remains unchanged, due to the decrease in the pressure difference between adjacent cavities, the leakage rate is reduced.

[0038] At the turning of the labyrinth seal structure of the lower seal plate and the upper seal plate, the flow rate of the labyrinth seal air flow channel can be adjusted by installing a colloid, an adjusting ring, and an adjusting bolt, as Figure 6 shown in the figure. The colloid can use a gum with a relatively low concentration. The concentration of the gum is selected to have the best effect at 15%, making it have physical properties similar to chewing gum, that is, having good adhesiveness and deformability and very low stiffness characteristics.

[0039] Since the maximum gas flow velocity of the labyrinth seal structure with comb teeth is the speed of sound, and the leakage rate m of a certain cross-section is:

[0040] m = ρFv (2)

[0041] Therefore, the leakage rate can be reduced by reducing the leakage area F here, that is, by tightening the adjusting bolt to squeeze the adjusting ring downward, reducing the leakage area F between the colloid and the inner ring of the guide, causing gas congestion here, and thus reducing the leakage rate; and because the stiffness of the colloid is very low, the deformation of the inner ring of the guide is negligible due to the influence of the colloid, and it can still be considered as a non-contact seal here.

[0042] The sealing form between the upper seal plate and the air-adjusting screw is also a labyrinth seal structure, as Figure 7 shown in the figure. According to formula (2), the diameter of the air-adjusting screw can be designed to be a smaller value to make the leakage area F lower, thereby reducing the leakage rate. Even if gas congestion occurs here, further sealing can be carried out on the upper surface of the upper seal plate and the air-adjusting screw to further reduce the leakage rate. At the same time, since part or all of the gas in cavity c comes from cavity a and cavity b, if the exhaust rate here is too slow, it will cause the air pressure in cavity c to overload. Therefore, the part of the air-adjusting screw connected to the lower seal plate is set as a threaded connection, so as to adjust the labyrinth seal length between the exhaust screw and the upper seal plate by the rise or fall of the thread, and then adjust the air output volume to ensure that cavity c will not be overloaded.

[0043] Since the exhaust at the outside of cavity b is directly connected to the atmosphere, to reduce the exhaust rate, a honeycomb ring structure can be installed at the exhaust to make the gas flow do work in the honeycomb, as Figure 8 shown in the figure. According to the Bernoulli equation of gas dynamics:

[0044]

[0045] Therefore, the work w done when the gas flows can be increased f , so as to reduce the air flow outlet speed and further reduce the outlet exhaust volume.

[0046] In summary, when the non-contact sealed air pressure loading device shown in Figure 4 is used to apply air pressure loading to the inner ring of the guide vane, the air flow channels between the a, b, and c chambers and the atmosphere adopt a non-contact seal in the form of "comb-type labyrinth seal + choke seal + honeycomb deceleration", and the air flow rate can be adjusted through the colloid, adjusting ring, and air adjusting screw, so that the air pressure and gas flow rate have good controllability.

[0047] 1. An air pressure loading test loading scheme for the non-contact air pressure loading of the inner ring of the guide vane in the form of "comb-type labyrinth seal + choke seal + honeycomb deceleration" is adopted;

[0048] 2. A control method for adjusting the air flow outflow volume by using the colloid, adjusting ring, and air adjusting screw under this loading scheme

[0049] As described above, it is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claimed rights.

Claims

1. A non-contact seal air pressure loading test device for the inner ring of a turbine guide vane. After the device is connected to the inner ring (2) of the guide vane, a pressure test is carried out. The inner ring (2) of the guide vane has a first arm (21), a second arm (22), a third arm (23) and a fourth arm (24), and is characterized in that, The non-contact sealed air pressure loading test device includes: An upper sealing plate (10) having a sealing groove into which the first arm (21) and the third arm (23) can be inserted. The groove wall of the sealing groove is of a labyrinth type, and the bottom of the sealing groove has an elastic colloid (7); the material of the colloid (7) includes 10% - 20% resin glue; A lower sealing plate (1) which is sealed and fixedly connected to the second arm (22) and also has the sealing groove at the fourth arm (24), and the fourth arm (24) is inserted and connected to the sealing groove; A connecting rod (6) with a spacer ring (4) sleeved in the middle, and one end of the upper sealing plate (10) and one end of the lower sealing plate (1) are respectively sleeved at both ends; An air adjusting screw (11) connected to the other end of the upper sealing plate (10) and the other end of the lower sealing plate (1). The air adjusting screw (11) has a threaded section and a labyrinth section, and the air adjusting screw (11) changes the contact area between the labyrinth section and the upper sealing plate (10) or the lower sealing plate (1) by screwing in and out; The minimum distance between the labyrinth teeth of the sealing groove and the upper sealing plate (10) or the lower sealing plate (1) gradually decreases from the outer end to the inner end of the sealing groove.

2. The non-contact seal air pressure loading test device for the inner ring of the turbine guide vane according to claim 1, wherein An adjusting bolt (8) is installed on the colloid (7), and the position of the colloid (7) is changed by rotating the adjusting bolt (8).

3. The non-contact seal air pressure loading test device for the inner ring of the turbine guide vane according to claim 1, characterized in that A honeycomb ring (5) is installed at the sealing groove of the first arm (21).

4. The non-contact seal air pressure loading test device for the inner ring of the turbine guide vane according to claim 2, wherein There is an adjusting ring between the adjusting bolt (8) and the colloid (7). The adjusting ring is threadedly connected to the adjusting bolt (8) and fixedly connected to the colloid (7).

5. The non-contact seal air pressure loading test device for the inner ring of the turbine guide vane according to claim 1, characterized in that The minimum distance between the labyrinth teeth of the sealing groove and the upper sealing plate (10) or the lower sealing plate (1) is not greater than one-tenth of the width of the sealing groove.

6. The non-contact seal air pressure loading test device for the inner ring of the turbine guide vane according to claim 3, wherein, The honeycomb ring (5) is connected with a support plate, and the support plate is sleeved on the connecting rod (6).

7. The non-contact seal air pressure loading test device for the inner ring of the turbine guide vane according to claim 1, characterized in that, The labyrinth section of the air adjusting screw (11) contacts the upper sealing plate (10) and is connected to the atmosphere, and the threaded section is connected to the lower sealing plate (1).

8. The non-contact seal air pressure loading test device for the inner ring of the turbine guide vane according to claim 7, characterized in that, There is a sealing strip at the connection between the labyrinth section and the atmosphere.

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