A turbine interstage seal structure and an aeroengine

Abstract

The application provides a turbine inter-stage sealing structure and an aero-engine, which comprises a turbine casing, a turbine static disc and a turbine dynamic disc which are coaxially arranged in the turbine casing, and the turbine dynamic disc can rotate relative to the turbine static disc; the turbine static disc comprises a first connecting part and a first outer edge part which are integrally connected and arranged from inside to outside along the radial direction of the turbine casing; the turbine dynamic disc comprises a second connecting part, a sealing part and a second outer edge part which are integrally connected and arranged from inside to outside along the radial direction of the turbine casing; a disc cavity outlet is arranged between the first outer edge part and the second outer edge part; the sealing cavity is arranged on the dynamic disc side in the turbine inter-stage sealing structure, and the inlet of the sealing cavity is opposite to the disc cavity outlet, that is, opposite to the invasion direction of the main flow gas, so that the main flow gas can generate vortex flow inside the sealing cavity and near the inlet of the sealing cavity, and the invasion of part of the main flow gas from the disc cavity outlet can be effectively prevented; the backflow of part of the main flow gas into the sealing cavity can also inhibit the invasion of the main flow gas.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine technology, specifically relating to a turbine stage sealing structure and an aero-engine. Background Technology

[0002] In turbomachinery such as aero-engines and heavy-duty gas turbines, after the high-temperature gas in the main flow path passes through the stationary blades, it is affected by the combined effects of the stationary blade wake and the potential flow field of the moving blades, resulting in alternating high-pressure and low-pressure flow zones along the circumference in the intermediate region between the rotating and stationary components. In the high-pressure flow zone, because the pressure in the main flow path is higher than the internal pressure of the turbine disk cavity, high-temperature main flow gas can leak into the inner cavity of the turbine disk, causing overheating of the turbine disk, leading to reduced turbine disk efficiency and a significantly shortened service life. Studies have shown that if the concentration of intruding gas in the disk cavity increases to a certain level, the service life of the turbine disk may decrease by 50%. Therefore, during turbine operation, it is necessary to effectively control the flow rate of high-temperature gas intruding into the inner cavity through the rational design of the secondary air cooling system. Although existing turbine interstage sealing structures can prevent the leakage of high-temperature gas in the main flow path to a certain extent, there is still a problem of relatively poor sealing effect due to limited gas expansion. In summary, improving the high-performance sealing structure is of great significance for improving turbine disk life and engine efficiency. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a turbine stage sealing structure and an aero-engine, which improves sealing efficiency and optimizes turbine disk sealing without increasing the amount of sealing cooling gas.

[0004] To achieve the above objectives, the present invention adopts the following technical solution.

[0005] A turbine stage sealing structure includes a turbine casing, in which a turbine stationary disk and a turbine moving disk are coaxially arranged opposite each other, and the turbine moving disk is rotatable relative to the turbine stationary disk.

[0006] The turbine stationary disc includes a first connecting portion and a first outer edge portion integrally connected from the inside to the outside along the radial direction of the turbine casing; the turbine moving disc includes a second connecting portion, a sealing portion, and a second outer edge portion integrally connected from the inside to the outside along the radial direction of the turbine casing; a disc cavity outlet is provided between the first outer edge portion and the second outer edge portion;

[0007] A stationary disc outer sealing ring extending towards the second outer edge is provided on the side of the first outer edge;

[0008] The bottom end of the sealing part is provided with a moving plate side sealing mechanism extending towards the first connecting part on the side facing the first connecting part;

[0009] The dynamic disc side sealing mechanism comprises a first sealing inner tooth, a circular annular boss ring and a second sealing inner tooth which are integrally connected; the first sealing inner tooth, the circular annular boss ring, the second sealing inner tooth and the side wall of the second outer edge part form a sealing cavity; the sealing cavity entrance is formed between the head end of the second sealing inner tooth and the inner wall of the second outer edge part, and the sealing cavity entrance is oppositely arranged with the disc cavity outlet;

[0010] The turbine casing forms a main flow channel with the turbine static disc and the turbine dynamic disc.

[0011] The first cold gas channel is formed between the inner side walls of the oppositely arranged first connecting part and the second connecting part; the second cold gas channel is formed between the inner side wall of the oppositely arranged first connecting part and the outer wall of the circular annular boss ring; the third cold gas channel is formed between the lower wall surface of the oppositely arranged first outer edge part and the upper wall surface of the second sealing inner tooth; the first cold gas channel is formed between the inner side wall of the oppositely arranged first outer edge part and the inner side wall of the second outer edge part; the first cold gas channel, the second cold gas channel, the third cold gas channel and the fourth cold gas channel are sequentially communicated to form a secondary flow channel.

[0012] The application also has the following technical features:

[0013] Specifically, the cross section of the sealing cavity is rectangular.

[0014] Further, a plurality of static vanes are arranged between the turbine casing and the turbine static disc, one end of the static vane is fixed on the inner wall of the turbine casing, and the other end is fixed on the turbine static disc; a plurality of dynamic vanes are arranged between the turbine casing and the turbine dynamic disc, one end of the dynamic vane is fixedly connected with the turbine dynamic disc, and a gap exists between the other end and the turbine casing.

[0015] Further, the axial width W of the sealing cavity entrance is greater than or equal to the axial width H of the disc cavity outlet.

[0016] Further, the axial width L of the sealing cavity and the axial width W of the sealing cavity entrance satisfy the following relationship: L>2W.

[0017] Further, the first sealing inner tooth and the circular annular boss ring are arranged perpendicularly to each other, and the circular annular boss ring and the second sealing inner tooth are arranged perpendicularly to each other.

[0018] Further, the distance h between the lower wall surface of the first outer edge part and the lower wall surface of the first sealing inner tooth and the radial depth b of the sealing cavity satisfy the following relationship: b<h / 2.

[0019] The wall thickness of the first sealing inner tooth, the circular annular boss ring and the second sealing inner tooth is 1-2mm.

[0020] The application also protects an aero-engine comprising the above-mentioned turbine inter-stage sealing structure.

[0021] Compared with the prior art, the present application has the following effects:

[0022] The turbine inter-stage sealing structure provided by the present application is provided with a sealing cavity on the side of the rotor disc, and the inlet of the sealing cavity is directly opposite the outlet of the disc cavity, i.e. directly opposite the invasion direction of the main flow gas. On the one hand, the main flow gas can generate vortex flow inside the sealing cavity and near the inlet of the sealing cavity, effectively preventing the invasion of part of the main flow gas from the disc cavity outlet and consuming part of the high-temperature gas. On the other hand, the backflow of part of the main flow gas into the sealing cavity can also inhibit the invasion of the main flow gas. At the same time, through the position setting of the sealing cavity, the sealing gap and the effective flow area between the sealing structure and the turbine static disc are reduced, and the outflow of the cold gas is ensured, and the overall structure is not negatively affected, so that the sealing structure can achieve a better sealing effect. Under the premise of not increasing the amount of sealing gas, a higher sealing efficiency can be obtained, and the working efficiency of the turbine is improved. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a schematic diagram of the overall structure of the present application;

[0024] Figure 2 is a schematic diagram of the gas flow characteristics in the disc cavity, wherein the arrow direction is the gas flow direction;

[0025] Figure 3 is a schematic diagram of the local structure of the present application;

[0026] Figure 4 (a) is a meridian plane sealing efficiency nephogram of a common radial sealing structure;

[0027] Figure 4 (b) is a meridian plane sealing efficiency nephogram of the turbine inter-stage sealing structure of Example 1;

[0028] Figure 5 (a) is a meridian plane sealing efficiency nephogram of a common radial sealing structure;

[0029] Figure 5 (b) is a meridian plane sealing efficiency nephogram of the turbine inter-stage sealing structure of Example 2;

[0030] Figure 6 (a) is a meridian plane sealing efficiency nephogram of a common radial sealing structure;

[0031] Figure 6 (b) is a meridian plane sealing efficiency nephogram of the turbine inter-stage sealing structure of Example 3.

[0032] The reference numerals in the figure represent:

[0033] 1-Turbine casing, 2-Turbine stationary disc, 3-Turbine moving disc, 4-Disc cavity outlet, 5-Sealing cavity, 6-Stationary blade, 7-Moving blade; 21-First connecting part, 22-First outer edge part; 31-Second connecting part, 32-Sealing part, 33-Second outer edge part; 51-Sealing cavity inlet; 321-Moving disc side sealing mechanism, 3211 First sealing internal tooth, 3212-Annular boss ring, 3213-Second sealing internal tooth.

[0034] The specific content of the present invention will be further explained in detail below with reference to the embodiments. Detailed Implementation

[0035] It should be noted that, unless otherwise specified, all components in this invention are components known in the prior art.

[0036] The terms “upper,” “lower,” “front,” “rear,” etc., used in this invention are for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. “Inner” and “outer” refer to the inner and outer contours of the corresponding components, and the above terms should not be construed as limitations on the invention.

[0037] In this invention, unless otherwise stated, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0038] Example 1

[0039] Following the above technical solutions, such as Figure 1 As shown, this embodiment discloses a turbine stage sealing structure, including a turbine casing 1, in which a turbine stationary disk 2 and a turbine moving disk 3 are coaxially arranged opposite each other, and the turbine moving disk 3 can rotate relative to the turbine stationary disk 2.

[0040] The turbine stationary disc 2 includes a first connecting portion 21 and a first outer edge portion 22 integrally connected from the inside to the outside along the radial direction of the turbine casing; the turbine moving disc 3 includes a second connecting portion 31, a sealing portion 32 and a second outer edge portion 33 integrally connected from the inside to the outside along the radial direction of the turbine casing; a disc cavity outlet 4 is provided between the first outer edge portion 22 and the second outer edge portion 33;

[0041] A stationary outer sealing ring 221 extending toward the second outer edge 33 is provided on the side of the first outer edge 22 facing the second outer edge 33;

[0042] The bottom end of the sealing part 32 is provided with a dynamic disc side sealing mechanism 321 extending towards the first connecting part 21;

[0043] The dynamic disc side sealing mechanism 321 comprises a first sealing inner tooth 3211, a circular ring-shaped boss ring 3212 and a second sealing inner tooth 3213 which are integrally connected; the first sealing inner tooth 3211, the circular ring-shaped boss ring 3212 and the second sealing inner tooth 3213 and the side wall of the second outer edge part 33 form a sealing cavity 5; the head end of the second sealing inner tooth 3213 and the inner wall of the second outer edge part 33 form a sealing cavity inlet 51, and the sealing cavity inlet 51 is arranged opposite to the disc cavity outlet 4.

[0044] Since the sealing cavity 5 is arranged, the flow speed of the invading main flow of gas can be effectively reduced, and the invasion of the high-temperature main flow of gas into the disc cavity is prevented. Since the sealing cavity 5 in the embodiment adopts a rotary structure, it is more difficult for the main flow of gas invading into the sealing cavity to flow out of the sealing cavity 5. Moreover, the sealing cavity 5 in the embodiment is arranged on the first profile after the main flow of gas enters the disc cavity inlet 4, and therefore, the sealing cavity 5 has a high dissipation degree for the main flow of gas.

[0045] The turbine casing 1, the turbine static disc 2 and the turbine dynamic disc 3 form a main flow channel; the high-temperature main flow of gas flows in the main flow channel.

[0046] The inner side wall of the oppositely arranged first connecting part 21 and the inner side wall of the second connecting part 31 form a first cold gas channel; the inner side wall of the oppositely arranged first connecting part 21 and the outer wall of the circular ring-shaped boss ring form a second cold gas channel; the lower wall surface of the oppositely arranged first outer edge part 22 and the upper wall surface of the second sealing inner tooth form a third cold gas channel; the inner side wall of the oppositely arranged first outer edge part 22 and the inner side wall of the second outer edge part 33 form a fourth cold gas channel; the first cold gas channel, the second cold gas channel, the third cold gas channel and the fourth cold gas channel are sequentially connected to form a secondary flow channel. The cold gas flows to the disc cavity outlet 4 through the secondary flow channel.

[0047] As a preferred scheme of the embodiment, the cross section of the sealing cavity 5 is rectangular.

[0048] As a preferred scheme of the embodiment, the turbine casing 1 and the turbine static disc 2 are further provided with a plurality of static blades 6, one end of each static blade 6 being fixed to the inner wall of the turbine casing 1 and the other end being fixed to the turbine static disc 2; the turbine casing 1 and the turbine dynamic disc 3 are further provided with a plurality of dynamic blades 7, one end of each dynamic blade 7 being fixedly connected to the turbine dynamic disc 3 and the other end having a gap with the turbine casing 1.

[0049] As a preferred solution of this embodiment, the axial width W of the seal cavity inlet 51 is greater than or equal to the axial width H of the disk cavity outlet 4, so that it is easier for the mainstream gas to enter the dynamic disk side seal cavity 5 after entering the disk cavity inlet 4.

[0050] As a preferred solution of this embodiment, the axial width L of the seal cavity 5 and the axial width W of the seal cavity inlet 51 satisfy the following relationship: L > 2W. The large seal cavity can consume more mainstream gas..

[0051] As a preferred solution of this embodiment, the first seal inner tooth 3211 and the circular boss ring 3212 are arranged perpendicular to each other, and the circular boss ring 3212 and the second seal inner tooth 3213 are arranged perpendicular to each other.

[0052] As a preferred solution of this embodiment, the distance h between the lower wall surface of the first outer edge part 22 and the lower wall surface of the first seal inner tooth 3211 and the radial depth b of the seal cavity 5 satisfy the relationship: b < h / 2, in order to prevent the seal flow passage from being too small to reduce the seal efficiency and prevent rubbing and scraping between the dynamic disk side seal mechanism and the static disk under the high-speed rotation state.

[0053] In this embodiment, h = 7 mm, b = 2.5 mm, W = 2 mm, H = 2 mm, L = 4.5 mm.

[0054] As a preferred solution of this embodiment, the wall thicknesses of the first seal inner tooth 3211, the circular boss ring 3212 and the second seal inner tooth 3213 are all 1 mm, that is Figure 3 S1 = S2 = S3 = 1 mm in

[0055] When this embodiment is in use:

[0056] After the mainstream gas entering through the mainstream flow passage flows into the disk cavity inlet 4, on the one hand, most of the mainstream gas can enter the inside of the seal cavity along the seal cavity inlet 51, generate a clockwise eddy current inside the seal cavity, and at the same time flow back along the inner wall surface of the seal cavity, generating an eddy current in the third cold air channel, thereby blocking part of the mainstream gas from invading into the disk cavity. At the same time, the eddy current can also consume a large amount of the invaded high-temperature mainstream gas; on the other hand, the cold air flowing along the inner wall surface of the turbine rotor disk 3 and in the opposite direction to the mainstream gas flow direction is mixed with the mainstream gas in the third cold air channel, which can effectively block part of the mainstream gas flowing into the disk cavity, so as to effectively improve the sealing effect without increasing the sealing gas consumption.

[0057] Performance test

[0058] The turbine stage seal structure provided in this embodiment is compared with the existing ordinary radial seal structure, and the meridian plane seal efficiency contour map as Figure 4 shown is obtained. FromFigure 4 As can be seen, after some of the mainstream gas invades the cavity, it enters the sealed cavity 5 along the inlet 51, consuming some of the high-temperature gas and forming a vortex structure at the inlet of the sealed cavity 5. This enhances the mixing ability of the mainstream gas and the cold air, further hindering the mainstream gas from invading into the cavity along the secondary flow channel. Compared with ordinary radial sealing, in this cloud diagram, the high sealing efficiency area has expanded from the original second cold air channel to the third cold air channel, indicating that the intrusion of the mainstream gas has been suppressed, thus proving that the sealing efficiency of the present invention has been significantly improved.

[0059] Example 2

[0060] The turbine stage inter-stage sealing structure provided in this embodiment is the same as the turbine stage inter-stage sealing structure provided in Embodiment 1 in terms of main structure. The only difference is that in this embodiment, h = 7mm, b = 2.5mm, W = 2mm, H = 2mm, and L = 6.5mm.

[0061] Performance testing

[0062] like Figure 5 As shown, in Example 2, the size of the sealing cavity is increased based on Example 1. The larger size of the sealing cavity allows it to accommodate more high-temperature gas. Based on Example 1, the high sealing efficiency area in the cloud diagram has expanded from the front section of the third cold air channel to the middle section of the third cold air channel, indicating that the intrusion of the mainstream gas has been suppressed. Compared with ordinary radial sealing and Example 1, the sealing efficiency of the sealing structure has been further improved.

[0063] Example 3

[0064] The turbine stage inter-stage sealing structure provided in this embodiment is the same as the turbine stage inter-stage sealing structure provided in Embodiment 1 in terms of main structure. The only difference is that in this embodiment, h = 7mm, b = 2.5mm, W = 3mm, H = 2mm, and L = 6.5mm.

[0065] like Figure 6 As shown, in Example 3, the size of the sealing cavity inlet 51 is increased compared to Example 2. With a larger inlet 51, the mainstream gas enters the sealing cavity 5 more frequently and experiences backflow, exacerbating the mixing of the mainstream gas with the cold air entering through the secondary flow channel, further hindering the intrusion of the mainstream gas into the cavity. Based on Example 2, the high sealing efficiency area in the cloud diagram expands from the middle section of the third cold air channel to the end of the third cold air channel, indicating that the intrusion of the mainstream gas is more effectively suppressed, and the sealing efficiency of the sealing mechanism is significantly improved.

[0066] Example 4

[0067] The embodiment provides an aero-engine, which comprises the turbine inter-stage sealing structure provided in the embodiment 1.

[0068] The above merely provides the embodiments of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation, or direct or indirect application in other related technical fields, which is made according to the content of the present application, is also included in the patent protection scope of the present application.

Claims

1. A turbine inter-stage sealing structure, comprising a turbine casing (1), a turbine static disc (2) and a turbine dynamic disc (3) being coaxially and oppositely arranged in the turbine casing (1), and the turbine dynamic disc (3) being rotatable relative to the turbine static disc (2), characterized in that the turbine static disc (2) comprises a first connecting portion (21) and a first outer edge portion (22) being integrally connected and arranged from inside to outside along the radial direction of the turbine casing; the turbine dynamic disc (3) comprises a second connecting portion (31), a sealing portion (32) and a second outer edge portion (33) being integrally connected and arranged from inside to outside along the radial direction of the turbine casing; a disc cavity outlet (4) is arranged between the first outer edge portion (22) and the second outer edge portion (33); a static disc outer sealing ring (221) extending to the second outer edge portion (33) is arranged on the side of the first outer edge portion (22) facing the second outer edge portion (33); a dynamic disc side sealing mechanism (321) extending to the first connecting portion (21) is arranged on the bottom end of the sealing portion (32) facing the first connecting portion (21); the dynamic disc side sealing mechanism (321) comprises a first sealing inner tooth (3211), a circular ring-shaped boss ring (3212) and a second sealing inner tooth (3213) being integrally connected; the first sealing inner tooth (3211), the circular ring-shaped boss ring (3212), the second sealing inner tooth (3213) and the side wall of the second outer edge portion (33) form a sealing cavity (5); the second sealing inner tooth (3213) and the inner wall of the second outer edge portion (33) form a sealing cavity inlet (51); the sealing cavity inlet (51) is oppositely arranged with the disc cavity outlet (4); the turbine casing (1), the turbine static disc (2) and the turbine dynamic disc (3) form a main flow channel; a first cold gas channel is formed between the inner side wall of the first connecting portion (21) and the inner side wall of the second connecting portion (31); a second cold gas channel is formed between the inner side wall of the first connecting portion (21) and the outer wall of the circular ring-shaped boss ring; a third cold gas channel is formed between the lower wall of the first outer edge portion (22) and the upper wall of the second sealing inner tooth; a first cold gas channel, a second cold gas channel, a third cold gas channel and a fourth cold gas channel are sequentially connected to form a secondary flow channel; the cross section of the sealing cavity (5) is rectangular; a plurality of static blades (6) are arranged between the turbine casing (1) and the turbine static disc (2), one end of each static blade (6) is fixed on the inner wall of the turbine casing (1), and the other end is fixed on the turbine static disc (2); a plurality of dynamic blades (7) are arranged between the turbine casing (1) and the turbine dynamic disc (3), one end of each dynamic blade (7) is fixedly connected with the turbine dynamic disc (3), and the other end has a gap with the turbine casing (1); the axial width W of the sealing cavity inlet (51) is greater than or equal to the axial width H of the disc cavity outlet (4); the axial width L of the sealing cavity (5) and the axial width W of the sealing cavity inlet (51) satisfy the following relationship: L>2W. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2. The turbine interstage seal as claimed in claim 1, wherein, ​ 3. The turbine interstage seal as in claim 1, wherein, ​ 4. The turbine interstage seal as in claim 1, wherein, ​ 5. The turbine interstage seal as in claim 1, wherein, The first sealing inner tooth (3211) is arranged perpendicularly to the circular annular boss ring (3212), and the circular annular boss ring (3212) is arranged perpendicularly to the second sealing inner tooth (3213).

6. The turbine interstage seal as in claim 1, wherein The distance h between the lower wall surface of the first outer edge portion (22) and the lower wall surface of the first sealing inner tooth (3211) and the radial depth b of the sealing cavity (5) satisfy the relationship: b < h / 2.

7. The turbine interstage seal as in claim 1, wherein The wall thickness of the first sealing inner tooth (3211), the circular annular boss ring (3212) and the second sealing inner tooth (3213) is 1-2 mm.

8. An aeroengine characterised in that, The turbine inter-stage sealing structure as claimed in any one of claims 1-7.

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