A turbine interstage seal with honeycomb seal and a gas turbine

Abstract

The application discloses a turbine inter-stage sealing structure with honeycomb sealing and a gas turbine, and belongs to the field of gas turbines. The turbine inter-stage sealing structure with honeycomb sealing comprises a turbine moving disc and a turbine static disc, a gap is arranged between the turbine moving disc and the turbine static disc, a radial sealing structure is arranged between the turbine moving disc and the turbine static disc, the radial sealing structure comprises two honeycomb cavity structures arranged on the turbine moving disc and the turbine static disc respectively, the two honeycomb cavity structures are arranged along the circumferences of the turbine moving disc and the turbine static disc respectively, the inlets of the two honeycomb cavity structures are opposite to the directions of high-temperature gas flow, the honeycomb cavity structures are used for increasing the flow resistance of the gas flow, and the honeycomb cavity structures are used for inhibiting the gas invasion phenomenon. Meanwhile, the honeycomb structure is used for maximizing the cavity space for vortex dissipation, and the honeycomb structure has excellent geometric mechanical properties, the mass of the turbine disc is reduced, and the overall structural strength is not reduced. The application can reduce the minimum sealing flow and improve the overall efficiency of the gas turbine.

Description

Technical Field

[0001] This invention belongs to the field of gas turbines, specifically relating to a turbine stage sealing structure with honeycomb seals and a gas turbine. Background Technology

[0002] With the further development of modern aero engines, the compressor pressure ratio of the most advanced aero engines now exceeds 40, and the turbine inlet temperature exceeds 2100K, far exceeding the temperature resistance limit of turbine metal components. This leads to overheating of hot-end components in the engine. Taking the first-stage turbine disk as an example, because there is a gap between the stationary disk where the stator is installed and the rotating disk where the rotor is installed, the mainstream high-temperature and high-pressure combustion gas can invade deep into the disk cavity through this gap, burning the turbine disk. In particular, the turbine's rotating disk (moving disk), due to its long-term operation under harsh conditions of high temperature and high speed, is subjected to high thermal stress and centrifugal tensile stress. Once it overheats, serious accidents such as turbine disk rupture will occur, reducing engine life and even endangering engine safety. Therefore, it is necessary to draw some air from the compressor into the disk cavity to resist the intrusion of the mainstream combustion gas. However, this presents two problems: if the amount of cold air introduced is too small, the mainstream high-temperature combustion gas will erode the turbine disk, greatly reducing the turbine's service life; however, if the amount of bleed air is too large, it will reduce the airflow used for work in the mainstream duct, reducing the overall efficiency of the gas turbine.

[0003] In the article "Advances in Gas Turbine Turbine Disk Gas Intrusion and Sealing Technology" published by Jia Xingyun et al. in the 6th issue of Thermal Power Engineering in June 2021, it was pointed out that if the sealing gap is blindly reduced, the gas intrusion will be weakened while the cold gas outflow will be suppressed. Although adding a more complex structure to the sealing gap will bring good sealing effect, the thermal deformation of the components under real working conditions may cause problems such as collision and scratching of the components on both sides.

[0004] Therefore, the novel honeycomb sealing structure provided by this invention, which can reduce the amount of cold air drawn from the compressor, has significant engineering application value.

[0005] Compared to traditional sealing structure designs, the honeycomb sealing turbine stage interstage sealing structure not only suppresses the intrusion of high-temperature combustion gases into the disk cavity, but also reduces the mass of the turbine disk. Furthermore, the excellent geometric and mechanical properties of the honeycomb structure also meet the overall structural strength requirements. Summary of the Invention

[0006] The technical problem to be solved:

[0007] To overcome the shortcomings of existing technologies, this invention provides a turbine stage sealing structure and a gas turbine with honeycomb seals. The inlet sections of the two honeycomb chambers are directly facing the direction of the mainstream gas flow. The high-temperature mainstream gas forms vortices in multiple chambers, which enhances vortex dissipation in the chambers and increases the gas flow resistance, thereby suppressing gas intrusion. At the same time, the honeycomb structure maximizes the chamber space for vortex dissipation and has excellent geometric and mechanical properties. While reducing the mass of the turbine disk, the overall structural strength is not reduced.

[0008] The technical solution of the present invention is: a turbine stage sealing structure with honeycomb seal, comprising a turbine moving disk and a turbine stationary disk, wherein a gap is provided between the turbine moving disk and the turbine stationary disk; a radial sealing structure is provided between the turbine moving disk and the turbine stationary disk, wherein the radial sealing structure comprises two honeycomb chamber structures respectively provided on the turbine moving disk and the turbine stationary disk;

[0009] The two honeycomb chamber structures are respectively arranged along the circumference of the turbine moving disk and the turbine stationary disk, and their inlets are directly opposite to the direction of the high-temperature gas flow to increase the resistance to gas flow.

[0010] A further technical solution of the present invention is: the honeycomb chamber structure includes a plurality of honeycomb units arranged circumferentially, the honeycomb unit being a regular hexagonal groove structure; wherein, the diameter of the honeycomb unit is D, the chamber depth of the honeycomb unit is h, and the distance between adjacent honeycomb units, i.e., the wall thickness of the honeycomb unit, is d.

[0011] A further technical solution of the present invention is: the honeycomb cavity structure of the turbine moving disk is located on the inner end face of the root of its shoulder, and the honeycomb cavity structure of the turbine stationary disk is located at the root of the outer wall of the shoulder, both facing the direction of the high-temperature gas flow; the radial width of the honeycomb cavity structure is the honeycomb structure arrangement width l.

[0012] A further technical solution of the present invention is: the honeycomb structure is arranged with a width l and a sealing axial gap S. c,ax , sealing radial clearance S c,rad The relationship between the three is: l = S c,ax =S c,rad .

[0013] A further technical solution of the present invention is: the wall thickness d of the honeycomb unit and the axial gap S of the seal are... c,ax The relationship is: d = 0.1S c,ax .

[0014] A further technical solution of the present invention is: the diameter D of the cellular unit and the axial gap S of the seal are... c,ax The relationship is: D = 0.45S c,ax .

[0015] A further technical solution of the present invention is: the relationship between the depth h of the honeycomb cavity and the radial thickness H of the shoulder of the turbine stationary disk is: h = 0.8H.

[0016] A further technical solution of the present invention is that the two honeycomb chamber structures are identical in size and shape.

[0017] A gas turbine includes a stator and a rotor. The stator is mounted on a turbine stationary disk, and the rotor is mounted on a turbine moving disk. A radial sealing structure is provided between the turbine moving disk and the turbine stationary disk. The radial sealing structure includes two honeycomb chamber structures respectively provided on the turbine moving disk and the turbine stationary disk. The inlet sections of the two honeycomb chambers are directly facing the direction of the high-temperature gas flow to increase the ability of the gas to invade the interior of the chamber.

[0018] Beneficial effects

[0019] The beneficial effects of this invention are as follows: At the sealing structure of this invention, the high-temperature mainstream generates strong vortices in the multiple chambers formed by the honeycomb structure, enhancing airflow mixing and energy dissipation, increasing the resistance to gas flow, thereby suppressing gas intrusion. This invention can achieve good sealing effect even at low sealing cold air flow rates, greatly reducing the minimum sealing flow rate (the minimum cold air flow rate required to prevent gas intrusion in the disk cavity), i.e., reducing the amount of cold air drawn from the compressor to suppress gas intrusion, thereby improving the overall efficiency of the gas turbine; secondly, due to the inherent characteristics of the honeycomb structure, while reducing the mass of the turbine disk, the overall structural strength is not reduced. Specific analysis is as follows:

[0020] 1. The inlet cross-section of the honeycomb chamber is directly facing the direction of the high-temperature gas flow, which increases the ability of the gas to invade the interior of the chamber.

[0021] 2. The honeycomb unit adopts a regular hexagonal honeycomb structure, which maximizes the cavity space for vortex dissipation and enhances the airflow mixing and energy dissipation inside the honeycomb cavity.

[0022] 3. The honeycomb structure maximizes the chamber space for vortex dissipation. The honeycomb structure has excellent geometric and mechanical properties and reduces the mass of the turbine disk without reducing the overall structural strength. Attached Figure Description

[0023] Figure 1 It is a schematic diagram of the geometry of a single-stage turbine with a honeycomb seal;

[0024] Figure 2 This is a schematic diagram of the flow characteristics at the interstage seal with a honeycomb seal;

[0025] Figure 3 This is an enlarged schematic diagram of the honeycomb structure and the interstage sealing structure.

[0026] Explanation of reference numerals in the attached drawings: 1-Turbine moving disk, 2-Turbine stationary disk, 3-Radial sealing structure, 4-Cellular cell diameter D, 5-Cellular cell wall thickness d, 6-Radial thickness H of the shoulder of the turbine stationary disk, 7-Cellular chamber depth h, 8-Axial clearance S of the sealing layer c,ax 9-Sealing radial clearance S c,rad , 10-Cellular structure arrangement width l. Detailed Implementation

[0027] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0028] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this 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. Therefore, they should not be construed as limitations on this invention.

[0029] See Figure 1-2 As shown, this invention provides a turbine stage interstage sealing structure with honeycomb seals, including a turbine moving disk 1 and a turbine stationary disk 2, with a gap between them. A radial sealing structure 3 is provided between the turbine moving disk 1 and the turbine stationary disk 2, comprising two honeycomb chamber structures respectively disposed on the turbine moving disk and the turbine stationary disk. The two honeycomb chamber structures are respectively arranged along the circumference of the turbine moving disk and the turbine stationary disk, and their inlets are directly opposite to the direction of high-temperature gas flow to increase the gas flow resistance. The high-temperature gas forms vortices in multiple chambers, enhancing vortex dissipation within the chambers and increasing the gas flow resistance, thereby suppressing gas intrusion.

[0030] Reference Figure 3 As shown, the honeycomb chamber structure includes a plurality of honeycomb units arranged circumferentially, and the honeycomb unit is a regular hexagonal groove structure; wherein, the diameter of the honeycomb unit is D, the chamber depth of the honeycomb unit is h, and the distance between adjacent honeycomb units, i.e., the wall thickness of the honeycomb unit, is d.

[0031] Reference Figure 3 As shown, the honeycomb cavity structure of the turbine moving disk 1 is located on the inner end face of the root of its shoulder, and the honeycomb cavity structure of the turbine stationary disk 2 is located at the root of the outer wall of the shoulder. Both are directly opposite to the direction of the high-temperature gas flow, and the size and shape of the two honeycomb cavity structures are the same; the radial width of the honeycomb cavity structure is the honeycomb structure arrangement width l.

[0032] Preferably, the honeycomb structure is arranged with a width l and a sealing axial gap S. c,ax , sealing radial clearance S c,rad The relationship between the three is: l = S c,ax =S c,rad .

[0033] Preferably, the cell cell wall thickness d and the sealing axial gap S c,ax The relationship is: d = 0.1S c,ax .

[0034] Preferably, the diameter D of the cellular unit and the axial gap S of the seal are... c,ax The relationship is: D = 0.45S c,ax .

[0035] Preferably, the relationship between the depth h of the honeycomb chamber and the radial thickness H of the shoulder of the turbine stationary disk is: h = 0.8H.

[0036] The sealing effect of this sealing structure has been verified through numerical simulation. The verification method compares the sealing effects with and without the honeycomb sealing structure. By setting the same mainstream and sealing flow conditions, the sealing efficiency of the disk cavity with and without the honeycomb sealing structure is calculated and compared with the sealing flow rate. The unit size and layout of the two honeycomb structures have been defined.

[0037] Table 1 shows the sealing efficiency with and without honeycomb structures obtained through numerical calculations:

[0038] Sealing flow rate g / s 2.3 5.0 11.2 No honeycomb 0.26 0.54 0.87 There is a honeycomb 0.48 0.71 0.96

[0039] As shown in Table 1, the sealing efficiency was improved to the greatest extent at a low sealing flow rate (2.3 g / s), with an improvement of 84.6%, while the improvement was lower at a high sealing flow rate (11.2 g / s), at 10.3%. The numerical results indicate that the sealing efficiency was improved compared to the original structure at all sealing flow rates.

[0040] In this embodiment, a regular hexagonal honeycomb structure is used to maximize the chamber space for vortex dissipation. This structure also has excellent geometric and mechanical properties, and the overall structural strength is not reduced while the mass of the turbine disk is reduced.

[0041] In this embodiment, the relationship between the honeycomb structure arrangement width l, the sealing axial gap Sc,ax, and the sealing radial gap Sc,rad is: l = Sc,ax = Sc,rad = 4mm.

[0042] In this embodiment, the relationship between the radial height H of the inner tooth of the rim seal and the depth h of the honeycomb cavity is: H = 3mm, h = 0.8H = 2.4mm.

[0043] In this embodiment, the relationship between the cell wall thickness d and the sealing axial gap Sc,ax is: d = 0.1Sc,ax = 0.4mm.

[0044] In this embodiment, the relationship between the cellular cell diameter D and the sealing axial clearance Sc,ax is: D = 0.45Sc,ax = 1.8 mm.

[0045] See Figure 2 This invention generates strong vortices in the honeycomb cavity due to the high temperature mainstream, which enhances the mixing of airflow and energy dissipation inside the disk cavity, increases the resistance to gas flow, and enables a good sealing effect even under low sealing cold gas flow. At the same time, the use of honeycomb structure maximizes the cavity space for vortex dissipation, and the structure has excellent geometric and mechanical properties, reducing the mass of the turbine disk without reducing the overall structural strength.

[0046] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A turbine stage interstage sealing structure with a honeycomb seal, comprising a turbine moving disk and a turbine stationary disk, wherein a gap is provided between the turbine moving disk and the turbine stationary disk; characterized in that: A radial sealing structure is provided between the turbine moving disk and the turbine stationary disk, and the radial sealing structure includes two honeycomb chamber structures respectively provided on the turbine moving disk and the turbine stationary disk; The two honeycomb chamber structures are respectively arranged along the circumference of the turbine moving disk and the turbine stationary disk, and their inlets are directly opposite to the direction of the high-temperature gas flow to increase the resistance to gas flow. The honeycomb chamber structure includes a plurality of honeycomb units arranged circumferentially, wherein each honeycomb unit is a regular hexagonal groove structure; wherein, the diameter of the honeycomb unit is... D， The chamber depth of the cellular unit is h， The distance between adjacent cellular cells is the cellular cell wall thickness. d； The honeycomb cavity structure of the turbine moving disk is located on the inner end face of its shoulder root, and the honeycomb cavity structure of the turbine stationary disk is located at the root of the outer wall of the shoulder, both facing the direction of the high-temperature gas flow; the radial width of the honeycomb cavity structure is the honeycomb structure arrangement width. l ; The honeycomb structure arrangement width l 1. Seal the axial clearance S c,ax Seal the radial gap S c,rad The relationship among the three is as follows: l = S c,ax = S c,rad ; The wall thickness of the cellular unit d Axial clearance with seal S c,ax The relationship is: d =0.1 S c,ax ; The diameter of the cellular unit D Axial clearance with seal S c,ax The relationship is: D =0.45 S c,ax ; The cavity depth of the cellular unit h radial thickness of the shoulder of the turbine stationary disc H The relationship is: h =0.8 H； At the sealing structure, the high-temperature mainstream generates strong eddies in the multiple chambers formed by the honeycomb structure, which enhances airflow mixing and energy dissipation, increases the resistance to gas flow, and thus suppresses gas intrusion. Under the low flow condition of sealing flow rate of 2.3 g / s, the sealing efficiency of the sealing structure is improved by 84.6% compared with the non-honeycomb sealing structure.

2. The turbine stage sealing structure with honeycomb seal according to claim 1, characterized in that: The two honeycomb chamber structures are identical in size and shape.

3. A gas turbine, comprising a stator and a rotor, wherein the stator is mounted on a turbine stationary disk and the rotor is mounted on a turbine moving disk; characterized in that: A radial sealing structure is provided between the turbine moving disk and the turbine stationary disk, and the sealing structure is the sealing structure described in any one of claims 1-2.

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