Turbine sealing structure and gas turbine

Abstract

The utility model discloses a turbine sealing structure which comprises an inner holding ring, an outer holding ring and a metal sealing ring, the outer holding ring and the inner holding ring are respectively provided with a sealing area, the sealing area of the outer holding ring and the sealing area of the inner holding ring are both of an annular structure, and the sealing area of the outer holding ring is located on the radial outer side of the sealing area of the inner holding ring. An annular groove is formed in the sealing area of the outer holding ring, a notch of the annular groove faces the sealing area of the inner holding ring, and the metal sealing ring is arranged in the annular groove. In the hot state, the radial inner side of the metal sealing ring is in interference fit with the radial outer side of the sealing area of the inner holding ring, and at least one axial end face of the metal sealing ring is in interference fit with the corresponding axial end face of the annular groove. Therefore, thermal-state sealing can be achieved, and high-temperature and high-pressure fuel gas on the through-flow side is prevented from flowing to the non-through-flow side when the turbine works (the turbine is inevitably in a thermal state during working).

Description

Technical Field

[0001] The utility model belongs to the technical field of the turbine side of a gas turbine, and in particular relates to a turbine sealing structure and a gas turbine. Background Art

[0002] As China's carbon neutrality is promoted, gas turbines with flexible applications will have greater value in the future. In the development of gas turbines, improving the efficiency of the whole machine is both the focus and the difficulty, and the sealing problem on the high-temperature turbine side is a very important one. It is required to effectively ensure the sealing of flow and non-flow to improve the efficiency of the gas turbine, and the sealing structure is required to be as simple as possible to facilitate disassembly and assembly.

[0003] In the patent with publication number CN115370427A, a turbine sealing assembly is disclosed. However, in order to ensure sealing, the sealing structure of the turbine sealing assembly is complex, and there are protruding structures with circular cross-sections at both ends. The manuscript does not specify whether this structure is integral with the seal or separate from the seal. If this structure is separate from the seal, it cannot be fixed on the seal and the sealing cannot be ensured; if this structure is integral with the seal, it is difficult to manufacture, and in actual operation, stress concentration may occur here, causing the sealing ring to break. And when the gas temperature or gas pressure on the flow side and the non-flow side changes, the seal will bulge and deform toward one side, and there will be a displacement change in the groove. It is possible that the seal will slip out of the groove and cause high-temperature gas leakage. Utility Model Content

[0004] The utility model aims to provide a new turbine sealing structure and a gas turbine, which can effectively prevent the leakage of high-temperature gas in the turbine side flow of the gas turbine to the non-flow area.

[0005] The technical solution of the utility model is:

[0006] A turbine sealing structure, comprising an inner holding ring, an outer holding ring and a metal sealing ring, wherein the outer holding ring and the inner holding ring respectively have a sealing area, the sealing areas of the outer holding ring and the inner holding ring are both annular structures, and the sealing area of ​​the outer holding ring is located radially outside the sealing area of ​​the inner holding ring;

[0007] An annular groove is provided on the sealing area of ​​the outer holding ring, the notch of the annular groove is arranged toward the sealing area of ​​the inner holding ring, and the metal sealing ring is arranged in the annular groove; in a hot state, the radial inner side of the metal sealing ring is interference fit with the radial outer side of the sealing area of ​​the inner holding ring, and at least one axial end face of the metal sealing ring is interference fit with the corresponding axial end face on the annular groove.

[0008] In the turbine sealing structure described in one embodiment, the metal sealing ring is formed by metal strips arranged in a ring shape, and the two ends of the metal strips have overlapping areas in the circumferential direction; the length of the overlapping area in the circumferential direction is adjustable to adjust the inner diameter of the metal sealing ring.

[0009] In the turbine sealing structure described in one embodiment, the metal strip is divided into a first end section, a main section, and a second end section in sequence along the length direction;

[0010] The first end section has a uniform thickness in the axial direction, the main body section has a uniform thickness in the axial direction, and the second end section has a uniform thickness in the axial direction, and the sum of the thickness of the first end section in the axial direction and the thickness of the second end section in the axial direction is equal to the thickness of the main body section in the axial direction;

[0011] The surfaces of the first end segment and the main segment facing the first axial end are located in the same plane, and the surfaces of the second end segment and the main segment facing the second axial end are located in the same plane; the surface of the first end segment facing the second axial end and the surface of the second end segment facing the first axial end are at least partially in contact with each other to cooperate to form the overlapping area.

[0012] In the turbine sealing structure described in one embodiment, when in a cold state, there is a gap between the radial outer side of the metal sealing ring and the groove bottom surface of the annular groove.

[0013] In a turbine sealing structure described in a certain embodiment, when in a cold state, the radial inner side of the metal sealing ring and the radial outer side of the sealing area of ​​the inner holding ring are interference fit in the absence of external force.

[0014] In a turbine sealing structure described in a certain embodiment, when in a cold state, the radial inner side of the metal sealing ring and the radial outer side of the sealing area of ​​the inner holding ring are interference-fitted without the action of external force;

[0015] A first step surface is formed at the connection between the main body section and the first end section due to a thickness change in the axial direction, and a second step surface is formed at the connection between the main body section and the second end section due to a thickness change in the axial direction;

[0016] At least one of the circumferential end surface of the first end section and the second step surface, and the circumferential end surface of the second end section and the first step surface, is provided with a mounting portion that vaporizes when hot when installed in a cold state, and the mounting portion is used to expand the metal sealing ring to an inner diameter that is larger than the outer diameter of the sealing area of ​​the inner holding ring.

[0017] In the turbine sealing structure described in one embodiment, the mounting portion includes at least one gasket; when the mounting portion includes a plurality of gaskets, the plurality of gaskets are arranged along the circumferential direction.

[0018] In the turbine sealing structure described in one embodiment, the mounting portion includes at least one vinyl gasket.

[0019] A turbine sealing structure comprises an inner holding ring, an outer holding ring and a metal sealing ring, wherein the outer holding ring and the inner holding ring respectively have a sealing area, and the sealing areas of the outer holding ring and the inner holding ring are both annular structures; the metal sealing ring is arranged between the sealing area of ​​the outer holding ring and the sealing area of ​​the inner holding ring, and in a hot state, the metal sealing ring is interference fit with the sealing areas of the outer holding ring and the sealing areas of the inner holding ring to achieve sealing.

[0020] A gas turbine, wherein a turbine sealing structure as described in any one of the above items is provided on the turbine of the gas turbine.

[0021] Due to the adoption of the above technical solution, the utility model has the following advantages and positive effects compared with the prior art:

[0022] The turbine sealing structure and gas turbine provided by the utility model effectively prevent leakage of high-temperature gas in the turbine side flow of the gas turbine to the non-flow area by arranging a metal sealing ring between the inner holding ring and the outer holding ring, which not only avoids thermal damage to the components in the non-flow area, but also improves the efficiency of the gas turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] By reading the detailed description of the preferred embodiment below, various other advantages and benefits will become clear to those skilled in the art. The accompanying drawings are only for the purpose of illustrating the preferred embodiment and are not to be considered as limiting the present invention.

[0024] Figure 1 This is a schematic structural diagram of a turbine sealing structure of the utility model;

[0025] Figure 2 This is a structural schematic diagram of an annular sealing ring of the utility model;

[0026] Figure 3 This is a structural schematic diagram of an annular sealing ring of the utility model;

[0027] Figure 4 The utility model is a schematic diagram of the installation of a turbine sealing structure.

[0028] Description of reference numerals:

[0029] 1: inner holding ring; 2: outer holding ring; 21: annular groove; 3: metal sealing ring; 31: first end section; 311: first surface; 312: first step surface; 32: main section; 33: second end section; 331: second surface; 332: second step surface; 4: stationary blade; 5: moving blade;

[0030] A: flow side; B: non-flow side. DETAILED DESCRIPTION

[0031] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the specific implementation methods of the utility model will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0032] In order to simplify the drawings, only the parts related to the utility model are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".

[0033] Example 1

[0034] The flow side A of the gas turbine section is high temperature and high pressure gas, and the non-flow side B is low temperature and low pressure air. If the high temperature and high pressure gas on the flow side A flows to the non-flow side B, it will cause thermal damage to the components on the non-flow side B and reduce the efficiency of the gas turbine. However, in order to facilitate installation and adjustment of the axial dynamic and static clearance, such as Figure 4 As shown, the inner holding ring 1 on the outside of the moving blade 5 and the outer holding ring 2 on the outside of the stationary blade 4 are designed as separate structures. Therefore, a sealing structure needs to be provided between the two to ensure sealing and prevent the high-temperature and high-pressure fuel gas on the flow side A from leaking to the non-flow side B.

[0035] See also Figures 1 to 4 The present embodiment provides a turbine sealing structure, comprising an inner holding ring 1, an outer holding ring 2 and a metal sealing ring 3. The outer holding ring 2 and the inner holding ring 1 respectively have a sealing area. The sealing areas of the outer holding ring 2 and the inner holding ring 1 are both annular structures. The sealing area of ​​the outer holding ring 2 is located radially outside the sealing area of ​​the inner holding ring 1. An annular groove 21 is provided on the sealing area of ​​the outer holding ring 2. The notch of the annular groove 21 is arranged toward the sealing area of ​​the inner holding ring 1. The metal sealing ring 3 is arranged in the annular groove 21.

[0036] In the hot state, the radial inner side of the metal sealing ring 3 is interference fit with the radial outer side of the sealing area of ​​the inner holding ring 1, and at least one axial end face of the metal sealing ring 3 is interference fit with the corresponding axial end face on the annular groove 21. In this way, hot sealing can be achieved to prevent the high-temperature and high-pressure gas on the flow side A from flowing to the non-flow side B when the turbine is working (it must be in a hot state when working).

[0037] Specifically, the metal sealing ring 3 is formed by a metal strip arranged in an annular shape, and the two ends of the metal strip have an overlapping area in the circumferential direction; the length of the overlapping area in the circumferential direction is adjustable to adjust the inner diameter of the metal sealing ring 3. In this way, when installing, the inner diameter of the metal sealing ring 3 can be reduced first (the corresponding outer diameter will also be reduced), so that it can be installed in the annular groove 21 on the outer holding ring 2; then the inner diameter of the metal sealing ring 3 is increased to facilitate the installation of the inner holding ring 1.

[0038] Specifically, Figure 2 and Figure 3 As shown, the metal strip is divided into a first end section 31, a main section 32 and a second end section 33 in the length direction. The thickness of the first end section 31 in the axial direction is consistent, the thickness of the main section 32 in the axial direction is consistent, and the thickness of the second end section 33 in the axial direction is consistent. The sum of the thickness of the first end section 31 in the axial direction and the thickness of the second end section 33 in the axial direction is equal to the thickness of the main section 32 in the axial direction. The surfaces of the first end section 31 and the main section 32 facing the first axial end are located in the same plane, and the surfaces of the second end section 33 and the main section 32 facing the second axial end are located in the same plane; the surface of the first end section 31 facing the second axial end (called the first surface 311) and the surface of the second end section 33 facing the first axial end (called the second surface 331) are at least partially fitted to form an overlapping area. By adjusting the length of the first surface 311 and the second surface 331 fitting, the inner diameter of the metal sealing ring 3 can be adjusted.

[0039] When hot, the radial inner side of the metal sealing ring 3 and the radial outer side of the sealing area of ​​the inner holding ring 1 have an interference fit; when cold, the radial inner side of the metal sealing ring 3 and the radial outer side of the sealing area of ​​the inner holding ring 1 have an interference fit without the action of external force; when the engine is hot, the metal sealing ring 3 and the inner holding ring 1 are thermally deformed, resulting in a larger interference fit between the two, so that the radial inner surface of the metal sealing ring 3 and the radial outer surface of the sealing area of ​​the inner holding ring 1 are tightly fitted when the engine is running, thereby achieving sealing.

[0040] When in hot state, at least one axial end face of the metal sealing ring 3 has an interference fit with the corresponding axial end face on the annular groove 21: when in cold state, there is a gap between the radial outer side of the metal sealing ring 3 and the groove bottom surface of the annular groove 21, and further, there is a gap between the metal sealing ring 3 and the two axial end faces of the annular groove 21, which is convenient for installation; when the engine is hot running, the metal sealing ring 3 and the outer holding ring 2 are thermally deformed and subjected to the pressure difference force between the flow side A and the non-flow side B, so that at least one axial end face of the metal sealing ring 3 can be tightly fitted and pressed on the axial end face corresponding to the annular groove 21. Generally, the two axial end faces of the metal sealing ring 3 will be tightly fitted and pressed on the axial end faces corresponding to the annular groove 21 respectively, and the metal sealing ring 3 can continue to expand to the position between the radial outer side of the metal sealing ring 3 and the groove bottom surface of the annular groove 21. If there is no gap between the radial outer side of the metal sealing ring 3 and the groove bottom surface of the annular groove 21, after the two axial end surfaces of the metal sealing ring 3 are tightly pressed against the corresponding axial end surfaces of the annular groove 21, the metal sealing ring 3 continues to expand, which may cause the axial end surface of the metal sealing ring 3 and the corresponding axial end surface on the annular groove 21 to be wavy and unable to ensure the tight fit, thereby causing sealing failure. Therefore, the design of the gap is reserved for the metal sealing ring 3 and the outer holding ring 2 to produce thermal deformation, and after the thermal deformation to at least one axial end surface of the metal sealing ring 3 can be tightly pressed against the corresponding axial end surface of the annular groove 21, the metal sealing ring 3 and the annular groove 21 continue to expand.

[0041] Furthermore, a first step surface 312 is formed at the connection between the main body section 32 and the first end section 31 due to the thickness change in the axial direction, and a second step surface 332 is formed at the connection between the main body section 32 and the second end section 33 due to the thickness change in the axial direction; between the circumferential end surface of the first end section 31 and the second step surface 332, and between the circumferential end surface of the second end section 33 and the first step surface 312, at least one of them is provided with a mounting portion that will vaporize in the hot state when installed in the cold state, and the mounting portion is used to expand the metal sealing ring 3 to an inner diameter larger than the outer diameter of the sealing area of ​​the inner holding ring 1. Specifically, the mounting portion may include at least one gasket; when the mounting portion includes multiple gaskets, the multiple gaskets are arranged circumferentially. Preferably, the gasket may be an ethylene gasket.

[0042] During cold installation, the outer diameter of the metal sealing ring 3 is reduced to a size that allows it to slide into the annular groove 21 of the outer holding ring 2 by adjusting the fitting length of the first surface 311 and the second surface 331 to be larger; then, a vinyl gasket is added between the circumferential end surface of the first end section 31 and the second step surface 332 and / or between the circumferential end surface of the second end section 33 and the first step surface 312 to expand the inner diameter of the metal sealing ring 3 to a size larger than the outer diameter of the sealing area of ​​the inner holding ring 1, and then the inner holding ring 1 is installed in place. When the engine is running in a hot state, the vinyl gasket is vaporized, and the inner diameter of the metal sealing ring 3 is restored to an interference state with the inner holding ring 1 to ensure sealing.

[0043] By selecting suitable materials for the metal sealing ring 3, the outer holding ring 2 and the inner holding ring 1, the turbine sealing structure provided in this embodiment can be used in scenarios with high temperatures of up to 600 to 1000°C and pressure differences of 2 to 15 bar.

[0044] The turbine sealing structure provided in this embodiment has the following characteristics: ① the structure is simple: the metal sealing ring 3, the sealing area of ​​the outer holding ring 2, and the sealing area of ​​the inner holding ring 1 are all full-circle annular structures and have no radial segmentation, and the cross-section of the metal sealing ring 3 can be rectangular; ② it is easy to disassemble and assemble: no additional tooling is required, and the inner diameter of the metal sealing ring 3 can be adjusted by relying on the structure of the first end section 31 and the second end section 33 designed on the metal sealing ring 3 itself, so that it can be installed in place very conveniently; ③ the operating temperature and pressure range is wide: it can be applied to the high-temperature and high-pressure turbine side of the gas turbine.

[0045] Example 2

[0046] The present embodiment provides a turbine sealing structure, including an inner holding ring, an outer holding ring and a metal sealing ring, the outer holding ring and the inner holding ring respectively have a sealing area, and the sealing areas of the outer holding ring and the inner holding ring are both annular structures; the metal sealing ring is arranged between the sealing area of ​​the outer holding ring and the sealing area of ​​the inner holding ring, and in a hot state, the metal sealing ring and the sealing areas of the outer holding ring and the inner holding ring are all interference fit to achieve sealing.

[0047] Specifically, the sealing area of ​​the outer holding ring may be located radially outside the sealing area of ​​the inner holding ring, and an annular groove is provided on the sealing area of ​​the inner holding ring, the notch of the annular groove is arranged toward the sealing area of ​​the outer holding ring, and the metal sealing ring is arranged in the annular groove. In the hot state, the radial outer side of the metal sealing ring is interference fit with the radial inner side of the sealing area of ​​the outer holding ring, and at least one axial end face of the metal sealing ring is interference fit with the corresponding axial end face of the annular groove. In this way, hot sealing is achieved to prevent the high-temperature and high-pressure gas on the flow side of the turbine from flowing to the non-flow side when the turbine is working (it must be in a hot state when working).

[0048] Alternatively, there is a gap between the axial end face of the sealing area of ​​the outer holding ring and the axial end face of the sealing area of ​​the inner holding ring, and annular grooves are respectively provided on the axial end face of the sealing area of ​​the outer holding ring and the axial end face of the sealing area of ​​the outer holding ring, and the axial ends of the metal sealing ring are respectively accommodated in the two annular grooves on the outer holding ring and the inner holding ring, and when hot, the two ends of the metal sealing ring are respectively interference fit with the two annular grooves on the outer holding ring and the inner holding ring to achieve sealing.

[0049] Example 3

[0050] This embodiment provides a gas turbine, and the turbine of the gas turbine is provided with a turbine sealing structure as described in Embodiment 1 or Embodiment 2.

[0051] The above is a detailed description of the embodiments of the present invention in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the protection scope of the present invention.

Claims

1. A turbine sealing structure, characterized in that: It includes an inner holding ring, an outer holding ring and a metal sealing ring, wherein the outer holding ring and the inner holding ring respectively have a sealing area, the sealing areas of the outer holding ring and the inner holding ring are both annular structures, and the sealing area of ​​the outer holding ring is located radially outside the sealing area of ​​the inner holding ring; An annular groove is provided on the sealing area of ​​the outer holding ring, the notch of the annular groove is arranged toward the sealing area of ​​the inner holding ring, and the metal sealing ring is arranged in the annular groove; in a hot state, the radial inner side of the metal sealing ring is interference fit with the radial outer side of the sealing area of ​​the inner holding ring, and at least one axial end face of the metal sealing ring is interference fit with the corresponding axial end face on the annular groove.

2. The turbine sealing structure according to claim 1, characterized in that: The metal sealing ring is formed by metal strips arranged in a ring shape, and both ends of the metal strips have overlapping areas in the circumferential direction; the length of the overlapping area in the circumferential direction is adjustable to adjust the inner diameter of the metal sealing ring.

3. The turbine sealing structure according to claim 2, characterized in that: The metal strip is divided into a first end section, a main section and a second end section in sequence along the length direction; The first end section has a uniform thickness in the axial direction, the main body section has a uniform thickness in the axial direction, and the second end section has a uniform thickness in the axial direction, and the sum of the thickness of the first end section in the axial direction and the thickness of the second end section in the axial direction is equal to the thickness of the main body section in the axial direction; The surfaces of the first end segment and the main segment facing the first axial end are located in the same plane, and the surfaces of the second end segment and the main segment facing the second axial end are located in the same plane; the surface of the first end segment facing the second axial end and the surface of the second end segment facing the first axial end are at least partially in contact with each other to cooperate to form the overlapping area.

4. The turbine sealing structure according to claim 1, characterized in that: In a cold state, a gap exists between the radial outer side of the metal sealing ring and the groove bottom surface of the annular groove.

5. The turbine sealing structure according to claim 1, characterized in that: In a cold state, the radial inner side of the metal sealing ring and the radial outer side of the sealing area of ​​the inner holding ring are interference fit in the absence of external force.

6. The turbine sealing structure according to claim 3, characterized in that: In a cold state, the radial inner side of the metal sealing ring and the radial outer side of the sealing area of ​​the inner holding ring are interference-fitted without the action of external force; A first step surface is formed at the connection between the main body section and the first end section due to a thickness change in the axial direction, and a second step surface is formed at the connection between the main body section and the second end section due to a thickness change in the axial direction; At least one of the circumferential end surface of the first end section and the second step surface, and the circumferential end surface of the second end section and the first step surface, is provided with a mounting portion that vaporizes when hot when installed in a cold state, and the mounting portion is used to expand the metal sealing ring to an inner diameter that is larger than the outer diameter of the sealing area of ​​the inner holding ring.

7. The turbine sealing structure according to claim 6, characterized in that: The mounting portion includes at least one gasket; when the mounting portion includes a plurality of gaskets, the plurality of gaskets are arranged along the circumferential direction.

8. The turbine sealing structure according to claim 6, characterized in that: The mounting portion includes at least one vinyl gasket.

9. A turbine sealing structure, characterized in that: It includes an inner holding ring, an outer holding ring and a metal sealing ring, the outer holding ring and the inner holding ring respectively have a sealing area, and the sealing areas of the outer holding ring and the inner holding ring are both annular structures; the metal sealing ring is arranged between the sealing area of ​​the outer holding ring and the sealing area of ​​the inner holding ring, and in a hot state, the metal sealing ring and the sealing areas of the outer holding ring and the inner holding ring are all interference fit to achieve sealing.

10. A gas turbine, characterized in that: The turbine of the gas turbine is provided with a turbine sealing structure as described in any one of claims 1 to 9.

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