Turbine disc rim sealing structure of gas turbine

Abstract

The invention provides a gas turbine disc rim sealing structure, and relates to the technical field of turbine disc inter-stage sealing, the gas turbine disc rim sealing structure comprises a movable disc and a static disc, and the radial edge of the movable disc and the radial edge of the static disc are matched with each other to form a sealing ring; a protrusion is arranged on the end face of the movable disc, and the protrusion is located on the inner side of the sealing ring and is close to the sealing ring. The protrusions are arranged on the movable disc and rotate along with the movable disc, the pressure and tangential speed of fluid in the disc cavity are increased, and therefore gas invasion flowing is greatly reduced, the minimum sealing cold air flow needed by turbine interstage sealing is greatly reduced, and the problem that the flow loss of an engine is increased due to the fact that the generated sealing cold air amount is too large is solved.

Description

Technical Field

[0001] The invention relates to the technical field of turbine disk interstage sealing, and in particular to a turbine disk rim sealing structure for a gas turbine. Background Art

[0002] The turbine in a gas turbine engine works under high temperature and high-speed rotation conditions for a long time, and is subject to very high thermal stress and centrifugal stress. Therefore, the rotor disk of the turbine is the key object of protection of the engine.

[0003] In the technology known to the inventor, sealing cold air is introduced into the rotor-static system disc cavity to prevent gas intrusion. If the sealing cold air is insufficient, the mainstream high-temperature gas will enter the engine through the rim seal, greatly reducing the life of the engine. This phenomenon of mainstream gas entering the disc cavity through the rim seal is called gas intrusion or gas backflow. However, introducing too much cold air will increase the flow loss of the engine and reduce efficiency.

[0004] Therefore, it is necessary to develop a new type of sealing structure to solve the above technical problems. Summary of the invention

[0005] The object of the present invention is to provide a gas turbine turbine disc rim sealing structure to solve the problems existing in the prior art. By arranging a protrusion on the moving disc, the protrusion rotates with the moving disc, thereby increasing the pressure and tangential velocity of the fluid inside the disc cavity, thereby greatly reducing the intrusion flow of the gas, and greatly reducing the minimum sealing cooling air flow required for the sealing between the turbine stages, thereby avoiding the problem of excessive sealing cooling air volume leading to increased engine flow losses.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A gas turbine turbine disc rim sealing structure includes a moving disc and a stationary disc, wherein the radial edge of the moving disc and the radial edge of the stationary disc cooperate with each other to form a sealing ring; a protrusion is arranged on the end face of the moving disc, and the protrusion is located on the inner side of the sealing ring and is arranged close to the sealing ring.

[0008] As one embodiment, an annular plate is provided near the edge of the moving disk, an annular groove is provided at the edge of the static disk, and the annular plate is inserted into the annular groove to form the sealing ring; the top end of the protrusion is closer to the end face of the static disk than the top end of the annular groove.

[0009] As an implementation manner, the height of the protrusion is not less than the height of the annular plate.

[0010] As one embodiment, a plurality of protrusions are evenly arranged along the circumferential direction.

[0011] As an implementation manner, the radial cross-sectional dimension of the protrusion gradually decreases from the bottom end to the top end.

[0012] As an embodiment, the protrusion is in a truncated cone shape.

[0013] As an embodiment, the protrusion is in the shape of a sand dune.

[0014] As an embodiment, the protrusion is in a prism shape.

[0015] Compared with the prior art, the present invention has the following technical effects:

[0016] The present invention provides protrusions on the moving disk, and the protrusions rotate with the moving disk, thereby increasing the pressure and tangential velocity of the fluid inside the disk cavity, thereby greatly reducing the intrusion flow of the fuel gas and greatly reducing the minimum sealing cooling air flow required for the sealing between the turbine stages, thereby avoiding the problem of increased engine flow loss caused by excessive sealing cooling air.

[0017] Other technical solutions of the present invention also have the following technical effects:

[0018] When the truncated cone-shaped protrusions are arranged on the moving disk in the present invention, the sealing efficiency can be improved while the corresponding additional torque can be effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] Figure 1 It is a structural schematic diagram of a gas turbine turbine disk rim sealing structure in one embodiment of the present invention;

[0021] Figure 2 It is a schematic diagram of a structure with a raised dune shape;

[0022] Figure 3 It is a schematic diagram of a structure in which the protrusion is in the shape of a truncated cone;

[0023] Figure 4 It is a schematic diagram of a structure in which the protrusion is in a prism shape.

[0024] Description of reference numerals:

[0025] 1. Static disk; 2. Moving disk; 3. Protrusion; 4. Sealing ring; 5. Dune-shaped protrusion; 6. Truncated cone-shaped protrusion; 7. Hexagonal cone-shaped protrusion. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The object of the present invention is to provide a gas turbine turbine disc rim sealing structure to solve the problems existing in the prior art. By arranging a protrusion on the moving disc, the protrusion rotates with the moving disc, thereby increasing the pressure and tangential velocity of the fluid inside the disc cavity, thereby greatly reducing the intrusion flow of the gas, and greatly reducing the minimum sealing cooling air flow required for the sealing between the turbine stages, thereby avoiding the problem of excessive sealing cooling air volume leading to increased engine flow losses.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] like Figure 1 to Figure 4 As shown, this embodiment provides a gas turbine turbine disk rim sealing structure, including a moving disk 2 and a stationary disk 1, the radial edge of the moving disk 2 and the radial edge of the stationary disk 1 cooperate with each other to form a sealing ring 4; a protrusion 3 is provided on the end face of the moving disk 2, and the protrusion 3 is located on the inner side of the sealing ring 4 and is arranged close to the sealing ring 4.

[0030] During operation, the protrusion 3 rotates with the moving disk 2, increasing the pressure and tangential velocity of the fluid inside the disk cavity, thereby greatly reducing the intrusion flow of the fuel gas and the minimum sealing cooling air flow required for the sealing between the turbine stages, thus avoiding the problem of increased engine flow losses due to excessive sealing cooling air.

[0031] It should be noted that after the protrusions 3 are arranged inside the disc cavity, the moving disc 2 will generate additional torque due to wind resistance. The additional torque will actually cause the protrusions 3 on the moving disc 2 to do work on the disc cavity fluid, thereby increasing the kinetic energy of the disc cavity fluid and increasing the pressure. At the same time, part of the work will become useless work due to wind resistance loss. Those skilled in the art can reasonably set the shape, number, and position of the protrusions 3 to reduce the wind resistance loss of the moving disc 2 caused by the protrusions 3, so that the additional torque of the moving disc 2 can be fully utilized. The number and position of the protrusions 3 are not limited in this embodiment.

[0032] In this embodiment, an annular plate is provided near the edge of the moving disk 2, and the annular plate is coaxial with the moving disk 2. An annular groove is provided on the edge of the static disk 1, and the annular groove is coaxial with both the static disk 1 and the moving disk 2. The annular plate is inserted into the annular groove to form a sealing ring 4. The top of the protrusion 3 in this embodiment at least exceeds the top of the annular groove. In other words, the top of the protrusion 3 is closer to the end face of the static disk 1 than the top of the annular groove.

[0033] As an implementation mode, in this embodiment, the height of the protrusion 3 is not less than the height of the annular plate. The height mentioned here refers to the dimension of the protrusion 3 or the annular plate in the axial direction of the moving plate 2 or the stationary plate 1.

[0034] In this embodiment, a plurality of protrusions 3 are evenly arranged along the circumferential direction. From the bottom to the top, the radial cross-sectional size of the protrusion 3 gradually decreases to reduce the additional torque required to be applied by the moving disk 2. Specifically, in this embodiment, the protrusion 3 is in the shape of a sand dune ( Figure 2 ), truncated cone ( Figure 3 ) or prism-shaped ( Figure 4 ).

[0035] The sealing effect of the sealing structure has been verified by simulation, and the verification method is to simulate and calculate the sealing characteristics after installing several different shapes of protrusions 3. Under the same mainstream conditions and the size structure of the sealing ring 4, the sealing efficiency of the disc cavity with protrusions 3 of different shapes installed on the moving disc 2 and the sealing efficiency of the disc cavity without protrusions 3 installed on the moving disc 2 are simulated and calculated respectively, and compared. The simulation uses six cases of truncated cone, hexagonal cone, sand dune, cylindrical, hexagonal prism and no protrusion 3 for comparison. Among them, the radius of the moving disc 2 is 267mm, the rotation speed is set to 2400 rpm, and the sealing cold air flow rate is 3.5g / s.

[0036] The sealing efficiency of different protrusion 3 shapes obtained through simulation calculation is shown in Table 1:

[0037] Table 1 Sealing efficiency effects of several protrusion shapes in simulation calculations

[0038]

[0039] It can be seen from Table 1 that no matter what shape the protrusion 3 is, it can significantly reduce the intrusion of gas and improve the sealing efficiency. The additional torque of the moving disk 2 caused by the protrusion 3 is related to the shape of the protrusion 3. Using simulation software post-processing, the torque of the structure with protrusion 3 minus the torque of the structure without protrusion 3 can obtain the additional torque generated by the protrusion 3.

[0040] Table 2 Comparison of additional torques of moving disks for several types of protrusion settings in experimental measurements

[0041]

[0042] It can be clearly found from Table 2 that, compared with the shape of the protrusion 3 having the same radial cross-sectional size from the bottom to the top, when the protrusion 3 has a shape in which the radial cross-sectional size gradually decreases from the bottom to the top, the additional torque of the moving disk is smaller. Moreover, among the protrusions 3 of several different shapes, when the protrusion 3 is truncated cone-shaped, the additional torque of the moving disk 2 is the smallest. Therefore, when the truncated cone-shaped protrusion 3 is arranged on the moving disk 2 in this embodiment, the corresponding additional torque can be effectively reduced while improving the sealing efficiency.

[0043] Adaptive changes made according to actual needs are all within the protection scope of the present invention.

[0044] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A gas turbine turbine disk rim sealing structure, characterized in that: It comprises a moving disc and a stationary disc, wherein the radial edge of the moving disc and the radial edge of the stationary disc cooperate with each other to form a sealing ring; a protrusion is arranged on the end surface of the moving disc, and the protrusion is located on the inner side of the sealing ring and is arranged close to the sealing ring.

2. The gas turbine turbine disk rim sealing structure according to claim 1, characterized in that: An annular plate is provided near the edge of the moving disk, an annular groove is provided at the edge of the static disk, and the annular plate is inserted into the annular groove to form the sealing ring; the top end of the protrusion is closer to the end face of the static disk than the top end of the annular groove.

3. The gas turbine disk rim sealing structure according to claim 2, characterized in that: The height of the protrusion is not less than the height of the annular plate.

4. The gas turbine disk rim sealing structure according to any one of claims 1 to 3, characterized in that: A plurality of protrusions are evenly arranged along the circumferential direction.

5. The gas turbine disk rim sealing structure according to claim 4, characterized in that: From the bottom end to the top end, the radial cross-sectional size of the protrusion gradually decreases.

6. The gas turbine turbine disk rim sealing structure according to claim 5, characterized in that: The protrusion is in a truncated cone shape.

7. The gas turbine disk rim sealing structure according to claim 5, characterized in that: The protrusion is in the shape of a sand dune.

8. The gas turbine disk rim sealing structure according to claim 5, characterized in that: The protrusion is in a prism shape.

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