A high-efficiency cooling structure suitable for a high-pressure turbine disc

Abstract

The application discloses a high-efficiency cooling structure suitable for a high-pressure turbine disc, which comprises a double-web turbine disc, a tenon for connecting turbine blades, fins arranged on the tenon, a mortise matched with the tenon and formed on a disc rim of the double-web turbine disc, and a gap between the tenon and the mortise as a first flow path; an air inlet hole communicated with a disc cavity is formed on a front web of the double-web turbine disc, an annular slot communicated with a disc hub is formed on one end of the disc cavity close to the disc hub, and a cold air outlet hole for making cold air flow out is formed on a bottom surface of the mortise and the tenon; the air inlet hole, the disc cavity and the cold air outlet hole form a second flow path; the annular slot, the disc cavity and the cold air outlet hole form a third flow path; and inner cavity fins are arranged on inner sides of front and rear webs of the turbine disc. The turbine disc and the tenon / mortise structure are cooled through the three cold air flow paths, and the heat exchange area is increased through the fin structure, so that the cooling efficiency is further improved.

Description

Technical Field

[0001] This invention relates to the field of thermal management technology for aero-engines, and in particular to a high-efficiency cooling structure suitable for high-pressure turbine disks. Background Technology

[0002] Statistics show that approximately half of all non-containment accidents in aero-engines are caused by turbine disk damage. As a core component of aero-engines, the high-pressure turbine disk must withstand centrifugal loads, thermal stress loads, and external loads during operation, making it a typical life-limited component. For turbine engines, the target of high thrust-to-weight ratio requires increasingly higher turbine inlet temperatures. Given the very limited increase in the temperature resistance limit of disk materials, efficient cooling and thermal protection of the turbine disk have become one of the core technologies of aero-engines. Traditional turbine disk thermal protection technologies mainly focus on two aspects: designing efficient turbine disk cooling structures and reducing heat transfer from high-temperature blades to the turbine disk. Significant research progress has been made in both areas.

[0003] In terms of turbine disk structure design, the double-spoke turbine disk is a high-pressure turbine disk design for next-generation high thrust-to-weight ratio turbofan engines, and it has great development potential in reducing turbine disk weight and improving cooling efficiency. Because the double-spoke turbine disk adopts a hollow structure, cooling air can directly enter the cavity formed by the front and rear spokes to cool the walls. Compared with the traditional single-spoke turbine disk, it can reduce weight by 17%-25% under the same strength conditions. It has a larger heat dissipation area, better cooling effect, and can also significantly reduce the amount of cooling air used. Some researchers have even added heat exchange structures such as fins to the double-spoke structure.

[0004] In reducing heat transfer from high-temperature blades, the design of cold air flow path arrangement and the optimization design of thermal resistance of tenon / mortise connection structure are of great research significance. For the double-spoke turbine disk structure, Zhao Xi et al. proposed several cold air arrangement schemes, such as central inlet-to-static cavity + central inlet-to-rotating cavity, central inlet-to-static cavity + high-position inlet-to-rotating cavity, etc., and conducted comparative analysis using numerical simulation method (Zhao Xi, Xu Guoqiang, Luo Xiang et al. Cold air arrangement scheme of hollow disk of equal weight [J]. Journal of Beijing University of Aeronautics and Astronautics, 2009, 35(05):527-531.DOI:10.13700 / j.bh.1001-5965.2009.05.013.). For the tenon / mortise connection structure, Lu Shan et al. proposed a three-dimensional structure optimization design method for double-spoke / tenon and established an optimization design platform. Optimization results show that the stress distribution of the double-spoke turbine disk is more uniform than that of the single-spoke turbine disk (Lu Shan, Zhao Lei. Optimization design method of double-spoke turbine disk / tenon structure [J]. Journal of Aerospace Power, 2014, 29(04): 875-880.).

[0005] While there has been considerable research progress on thermal protection technology for various local structures of turbine disks, comprehensive thermal protection technology that takes into account aspects such as double-spoke structure, flow path design, and tenon structure cooling optimization is still lacking. Summary of the Invention

[0006] Purpose of the invention: To address the above-mentioned shortcomings, the present invention provides a high-efficiency cooling structure suitable for high-pressure turbine disks.

[0007] Technical Solution: To solve the above problems, the present invention adopts a high-efficiency cooling structure suitable for high-pressure turbine disks, including a double-spoke turbine disk and tenons for connecting turbine blades. The double-spoke turbine disk includes front and rear spokes of the turbine disk and a hollow annular cavity formed by the front and rear spokes of the turbine disk. The inner side of the front and rear spokes of the turbine disk is provided with inner cavity fins arranged in a circular pattern around the center of the turbine disk. An annular slot communicating with the center of the disk is opened at one end of the cavity near the center of the disk. A mortise is opened on the edge of the double-spoke turbine disk to match the tenon. A cold air outlet hole communicating with the cavity is opened on the bottom surface of the mortise. An air inlet hole communicating with the cavity is opened on the front spoke of the turbine disk near the edge of the disk. The tenon is installed in the mortise. Several parallel fins are provided on one end of the tenon placed in the mortise. A gap is left between the inner end of the tenon and the bottom of the mortise. A through hole is opened on the tenon. The through hole, the cold air outlet hole and the gap are interconnected.

[0008] The two sides of the gap pass through the two sides of the turbine disk to form a first flow path; the air inlet, disk cavity, cold air outlet, gap, and through hole are connected in sequence to form a second flow path; the slot, disk cavity, cold air outlet, gap, and through hole are connected in sequence to form a third flow path.

[0009] Furthermore, the through hole and the cold air outlet hole are coaxially arranged as a cold air outlet channel, which is perpendicularly intersecting the first flow path.

[0010] Furthermore, the central axis of the air intake is at an angle of 10°-30° to the rotation axis of the turbine disk.

[0011] Furthermore, the radial height of the gap is 10%-60% of the total radial height of the tenon connection structure after the tenon is installed in the mortise.

[0012] Furthermore, the inner cavity fins include an inner layer of fins near the center of the disk and an outer layer of fins near the edge of the disk, both of which are arranged radially along the turbine disk.

[0013] Furthermore, the number of outer fins is twice the number of inner fins.

[0014] Furthermore, the air inlet is located between two adjacent outer fins.

[0015] Furthermore, the cross-section of the fin is rectangular.

[0016] Furthermore, the bottom ends of each fin are flush and the spacing between adjacent fins is equal.

[0017] Furthermore, the bottom cross-section of the tenon groove is one of a rectangle, trapezoid, or ellipse.

[0018] Beneficial effects: Compared with the prior art, the significant advantage of this invention is that it cools the turbine disk by designing multiple cooling channels on the double-spoke turbine disk and setting fin structures in the tenon and the inner cavity of the turbine disk to further increase the heat exchange area and effectively improve the cooling efficiency of the turbine disk. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the high-efficiency cooling structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the cooling flow path of the high-efficiency cooling structure of the present invention;

[0021] Figure 3 This is a schematic diagram of the circumferential distribution structure of the internal cavity fins of the present invention;

[0022] Figure 4 This is a schematic diagram of the tenon / mortise connection structure of the present invention;

[0023] Figure 5 This is a front view of the tenon / mortise connection structure of the present invention;

[0024] Figure 6 A comparison chart of the heat exchange capabilities of different cooling structures. Detailed Implementation

[0025] like Figure 1 As shown, this embodiment of a high-efficiency cooling structure suitable for high-pressure turbine disks includes a double-spoke turbine disk 1 and tenons 2 for connecting turbine blades. The double-spoke turbine disk 1 includes front and rear spokes of the turbine disk and a hollow annular cavity 4 formed by the front and rear spokes of the turbine disk. The inner sides of the front and rear spokes of the turbine disk are provided with inner cavity fins 5 arranged circumferentially around the center of the turbine disk. Figure 3 As shown, the inner cavity fins 5 are designed in two layers, including an inner layer fin 51 near the center 12 and an outer layer fin 52 near the edge 13. Both the inner layer fins 51 and the outer layer fins 52 are arranged radially along the turbine disk, and the number of outer layer fins 52 is twice the number of inner layer fins 51. Since the temperature of the turbine disk gradually increases from the center to the edge, the temperature at the high radius position near the edge is higher than that at the low radius position near the center. Therefore, more fins are set at the high radius position near the edge, which further enhances the cooling effect at the high radius position. At the same time, fewer fins are set at the low radius position near the center, which reduces the overall weight of the turbine disk and achieves better heat exchange effect, thereby improving the overall cooling efficiency of the turbine disk.

[0026] An annular slot 6 communicating with the center 12 is opened at one end of the disk cavity 4 near the center 12. A mortise 3 matching the tenon 2 is opened on the edge 13 of the double-spoke turbine disk 1. The bottom cross section of the mortise 3 is one of rectangle, trapezoid, or ellipse. In this embodiment, the bottom cross section of the mortise 3 is trapezoidal, and the sides of the trapezoid are connected by rounded transitions. A cold air outlet hole 8 communicating with the disk cavity 4 is opened on the bottom surface of the mortise 3. An air inlet hole 7 communicating with the disk cavity 4 is opened on the front spoke 11 of the turbine disk near the edge 13. The air inlet hole 7 is located between two adjacent outer fins 52, and the central axis of the air inlet hole 7 forms a 20° angle with the rotation axis of the turbine disk.

[0027] like Figure 4 and Figure 5 As shown, the tenon 2 is installed in the mortise 3. Several parallel fins 21 are provided on one end of the tenon 2 within the mortise 3. The cross-section of each fin 21 is rectangular, with the bottom ends of each fin flush and the spacing between adjacent fins equal. A gap 9 is left between the tenon 2 and the bottom of the mortise 3 as a channel for cold air circulation. The fins 21 are located within this gap 9. To ensure the strength and stress requirements of the turbine disk, the radial height h of the gap 9 from the root of the fin 21 to the bottom surface of the mortise 5 is 10%-60% of the total radial height H of the tenon connection structure after the tenon 4 is installed in the mortise 5. A through hole 10 is opened on the tenon 2. The through hole 10, the cold air outlet hole 7, and the gap 9 are interconnected. The through hole 10 and the cold air outlet hole 8 are coaxially arranged as a cold air outlet channel, which is perpendicular to the gap 9.

[0028] like Figure 2As shown, this invention provides three cooling flow paths for the turbine disk. The first flow path involves cooling gas flowing in from one end of the gap 9 between the tenon 2 and the mortise 3, and flowing out from the other end. This first flow path enhances heat transfer within the gap, reducing the temperature at the junction of the disk rim and blades. Simultaneously, the fin structure 21 increases the heat transfer area, further improving cooling efficiency. Furthermore, by controlling the contact surface area of ​​the tenon and mortise to be minimized while meeting strength and stress requirements, the contact thermal resistance is increased to reduce heat transfer, further lowering the turbine disk's operating temperature. In this example, the contact area between the tenon and mortise is reduced to 50% of its original size. The second flow path involves cooling gas entering the disk cavity 4 from the inlet 7, cooling the double-spoke turbine disk 1, and flowing out through the cold air outlet 8, the gap 9, and the through hole 10. The cold air in the second flow path originates from the sealing cavity upstream of the turbine disk, enabling cooling of the portion of the turbine disk near the rim. The third flow path allows cooling gas to enter the disk cavity 4 through the slot 3, cooling the double-spoke turbine disk 1 and exiting through the cold gas outlet hole 8, the gap 9, and the through hole 10. This third flow path passes through the entire turbine disk, thus providing overall cooling. The inner cavity fins 5 increase the heat exchange area of ​​the cooling gas within the disk cavity 4, helping to improve the heat exchange efficiency of the second and third flow paths. Through three cooling flow paths located at the bottom radius, middle radius, and high radius, the turbine disk undergoes multiple cooling processes, improving overall cooling efficiency. Furthermore, the cooling gas from the second and third flow paths, after exiting through the through hole 10, can further cool the turbine blades, further improving the utilization rate of the cooling gas.

[0029] To verify the cooling effect of the above structure, a numerical simulation experiment was conducted, and the experimental results are as follows: Figure 6 As shown, adding fins to the tenon of a traditional single-spoke turbine disk increases the heat exchange capacity by approximately 15.9% compared to the traditional single-spoke turbine disk. Replacing the single-spoke turbine disk with a double-spoke turbine disk by adding fins increases the heat exchange capacity by approximately 20% compared to the traditional single-spoke turbine disk. Using three cooling channels on the double-spoke turbine disk increases the heat exchange capacity by approximately 35.3% compared to the traditional single-spoke turbine disk. The integrated thermal protection structure combining fins, the double-spoke turbine disk, and the three cooling channels increases the heat exchange capacity by approximately 106.9% compared to the traditional single-spoke turbine disk. This demonstrates that the efficient cooling structure of this invention significantly improves the overall cooling efficiency.

Claims

1. A high-efficiency cooling structure suitable for high-pressure turbine disks, characterized in that, The device includes a double-spoke turbine disk (1) and tenons (2) for connecting turbine blades. The double-spoke turbine disk (1) includes front and rear spokes and a hollow annular cavity (4) formed by the front and rear spokes. The inner sides of the front and rear spokes are provided with inner cavity fins (5) arranged in a circular pattern around the center of the turbine disk. The end of the cavity (4) near the center (12) has an annular slot (6) communicating with the center (12). The edge (13) of the double-spoke turbine disk (1) has a mortise (3) that matches the tenon (2). The bottom surface of the groove (3) has a cold air outlet hole (8) that communicates with the disk cavity (4). The front spoke (11) of the turbine disk has an air inlet hole (7) that communicates with the disk cavity (4) near the disk edge (13). The tenon (2) is installed in the mortise (3). The end of the tenon (2) placed in the mortise (3) is provided with several parallel fins (21). The inner end of the tenon (2) and the bottom of the mortise (3) are left with a gap (9). The tenon (2) has a through hole (10). The through hole (10), the cold air outlet hole (8) and the gap (9) are interconnected. The two sides of the gap (9) pass through the two sides of the turbine disk (1) to form a first flow path; the air inlet (7), disk cavity (4), cold air outlet (8), gap (9), and through hole (10) are connected in sequence to form a second flow path; the annular slot (6), disk cavity (4), cold air outlet (8), gap (9), and through hole (10) are connected in sequence to form a third flow path.

2. The high-efficiency cooling structure for high-pressure turbine disks as described in claim 1, characterized in that, The through hole (10) and the cold air outlet hole (8) are coaxially arranged as a cold air outlet channel, and the cold air outlet channel is perpendicularly intersecting the first flow path.

3. The high-efficiency cooling structure for high-pressure turbine disks as described in claim 1, characterized in that, The central axis of the air inlet (7) forms an angle of 10°-30° with the rotating axis of the turbine disk.

4. The high-efficiency cooling structure for high-pressure turbine disks as described in claim 1, characterized in that, The radial height of the gap is 10%-60% of the total radial height of the tenon connection structure after the tenon (2) is installed in the mortise (3).

5. The high-efficiency cooling structure for high-pressure turbine disks as described in claim 1, characterized in that, The inner cavity fins (5) include an inner fin (51) near the center of the disk (12) and an outer fin (52) near the edge of the disk (13), both of which are arranged radially along the turbine disk.

6. The high-efficiency cooling structure for high-pressure turbine disks as described in claim 5, characterized in that, The number of outer fins (52) is twice the number of inner fins (51).

7. The high-efficiency cooling structure for high-pressure turbine disks as described in claim 6, characterized in that, The air inlet (7) is located between two adjacent outer fins (52).

8. The high-efficiency cooling structure for high-pressure turbine disks as described in claim 1, characterized in that, The cross-section of the fin (21) is rectangular.

9. The high-efficiency cooling structure for high-pressure turbine disks as described in claim 8, characterized in that, The bottom ends of each fin (21) are aligned and the spacing between adjacent fins (21) is equal.

10. The high-efficiency cooling structure for high-pressure turbine disks as described in claim 1, characterized in that, The bottom cross section of the tenon (3) is one of rectangle, trapezoid, or ellipse.

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