A column rib-jet hole coupled laminate cooling structure

Abstract

A kind of column rib-jet hole coupling's laminate cooling structure, it is related to gas turbine turbine blade cooling structure field.To solve the problem that existing double-wall cooling cannot simultaneously adopt thin outer wall and arrange large length-diameter ratio gas film hole to increase cooling efficiency, the present application includes by outer to inner sequentially and interval arrangement outer thin wall, middle layer wall and inner layer wall, and first column rib between outer thin wall and middle layer wall and second column rib between middle layer wall and inner layer wall;The through hole of the outer thin wall and middle layer wall is opened through first column rib between them, and forms gas film hole;The through hole of the middle layer wall and inner layer wall is opened through second column rib between them, and forms impact hole;The backflow hole in the middle layer wall is opened, for interlayer gas flow.The present application is mainly used for the cooling of turbine blade.

Description

Technical Field

[0001] This invention relates to the field of cooling structures for gas turbine blades, and more specifically to a laminated cooling structure with column rib-jet hole coupling. Background Technology

[0002] Gas turbines strive for high efficiency and high power density, leading to continuous increases in turbine inlet temperature. Currently, the turbine inlet temperature of advanced heavy-duty gas turbines has reached over 1700K, and the turbine inlet temperature of fourth-generation aero engines has reached over 1900K, far exceeding the allowable temperature of high-temperature alloys. This places higher demands on efficient cooling technology to ensure the safe operation of the turbine.

[0003] Sheet cooling is a new type of high-efficiency cooling structure. The outermost wall surface is arranged with diverging air film holes, which effectively block high-temperature combustion gases through the air film. The inner wall surface is arranged with an array of impact holes. The layers are connected by column ribs. By organizing the reasonable flow of cold air between the layers, heat exchange is enhanced and cooling efficiency is improved.

[0004] Double-wall cooling, similar to plate cooling structures, is a highly promising and efficient cooling structure. A typical double-wall structure consists of a near-wall array of impacts and a small aspect ratio fully covered film cooling system. Turbulence columns between the two walls further enhance internal flow heat transfer, increase the heat transfer area, and provide support to the outer wall. Studies have shown that further reducing the outer wall thickness helps to enhance heat transfer and improve cooling efficiency; however, a thinner outer wall reduces the aspect ratio of the film cooling orifices, leading to insufficient jet development within the orifices and reduced film cooling coverage. Furthermore, special orifice shapes such as fan-shaped orifices and backward-tilted orifices are difficult to arrange within thin walls due to their inherent high aspect ratio requirements.

[0005] Therefore, existing double-wall cooling systems cannot simultaneously employ thin outer walls and large aspect ratio film vents to increase cooling efficiency. Summary of the Invention

[0006] To address the problem that existing double-wall cooling systems cannot simultaneously utilize thin outer walls and arrange large aspect ratio film cooling holes to increase cooling efficiency, this invention provides a rib-jet hole coupled layered cooling structure. By arranging ribs conforming to the jet holes between the layers, the wall thickness is further reduced while meeting the requirement for large aspect ratio film cooling holes. Return holes are opened in the middle layer wall to weaken the crossflow effect caused by the accumulation of impact cold air between the layers.

[0007] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0008] A rib-jet-hole coupled layered cooling structure includes an outer thin-walled layer, a middle layer, and an inner layer arranged sequentially and at intervals from the outside to the inside, and a first rib disposed between the outer thin-walled layer and the middle layer, and a second rib disposed between the middle layer and the inner layer. A through-hole is formed between the outer thin-walled layer and the middle layer through the first rib, creating a gas film pore. A through-hole is formed between the middle layer and the inner layer through the second rib, creating an impact pore. Return holes are formed on the middle layer for the flow of interlayer gas.

[0009] Preferably, the two ends of the first column rib are integrally formed with the outer thin wall and the middle wall, respectively, and the two ends of the second column rib are integrally formed with the middle wall and the inner wall, respectively.

[0010] Preferably, the air film holes, impact holes, and return holes are arranged in N rows in the flow direction; adjacent rows of air film holes are arranged in a straight or staggered manner; adjacent rows of impact holes are arranged in a straight or staggered manner; adjacent rows of return holes are arranged in a straight or staggered manner; the air film holes and impact holes are arranged alternately in the longitudinal direction, and the return holes are arranged between adjacent rows of air film holes in the flow direction.

[0011] Preferably, the angle between the central axis of the air film pore and the outer thin wall is α, and the value of α ranges from 25° to 35° or from 145° to 155°.

[0012] Preferably, the angle between the central axis of the impact hole and the intermediate layer wall is set to β, where β = 90°.

[0013] Preferably, the inner diameter of the air film hole is d, the inner diameter of the impact hole is d′, and the inner diameter of the return hole is d″, where d = d′ = d″ = D.

[0014] Preferably, the thickness of the outer thin wall is p, the thickness of the middle wall is p′, and the thickness of the inner wall is p″, where p = p′ = p″ = D.

[0015] The beneficial effects of this invention compared to the prior art are:

[0016] 1. The cooling structure of this application adopts a three-layer design, which reduces the thermal resistance by reducing the thickness of the outer thin wall. At the same time, the impact hole and the second column rib adopt a conformal design, and the air film hole and the first column rib adopt a conformal design. This not only realizes the heat transfer enhancement effect of the column rib turbulence, but also meets the arrangement requirements of the large aspect ratio air film hole, so that the jet can fully develop in the hole and improve the air film cooling coverage performance.

[0017] 2. This application provides a reflux hole in the intermediate layer wall to reduce the crossflow effect caused by the accumulation of impact cold air between the layers, thereby improving the impact cooling performance.

[0018] 3. By selecting the jet direction of the air film orifice, this application can satisfy the air film adhesion under a wider range of cold air flow rate variations. Attached Figure Description

[0019] The accompanying drawings, which form part of this application, are provided to further illustrate the invention.

[0020] Figure 1 This is a top view of the forward jet from the air film orifice of the present invention.

[0021] Figure 2 for Figure 1 Sectional view at point AA.

[0022] Figure 3 for Figure 1 Three-dimensional cross-sectional view at point AA.

[0023] Figure 4 This is a top view of the reverse jet of the air film orifice according to the present invention.

[0024] Figure 5 for Figure 4 Sectional view at point BB.

[0025] Figure 6 for Figure 4 A three-dimensional sectional view at point BB.

[0026] Explanation of reference numerals in the attached diagram: 1-Outer thin wall; 2-Intermediate wall; 3-Inner wall; 4-First column rib; 5-Second column rib; 6-Air film pore; 7-Impact pore; 8-Return pore. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0028] See Figure 1 This application provides a rib-jet hole coupled plate cooling structure, which includes an outer thin wall 1, an intermediate wall 2, and an inner wall 3 arranged sequentially and at intervals from the outside to the inside, and a first rib 4 disposed between the outer thin wall 1 and the intermediate wall 2 and a second rib 5 disposed between the intermediate wall 2 and the inner wall 3; a through hole is formed between the outer thin wall 1 and the intermediate wall 2 through the first rib 4, forming a gas film hole 6; a through hole is formed between the intermediate wall 2 and the inner wall 3 through the second rib 5, forming an impact hole 7; and a return hole 8 is formed on the intermediate wall 2 for the flow of interlayer gas.

[0029] In this embodiment, the cooling structure adopts a three-layer design with inner and outer plates. At the same time, the impact hole 7 and the second column rib 5 adopt a conformal design, and the air film hole 6 and the first column rib 4 adopt a conformal design. This not only realizes the heat transfer enhancement effect of column rib turbulence, but also increases the aspect ratio of the air film hole 6, satisfying the arrangement of air film holes with a large aspect ratio.

[0030] In this embodiment, a reflux hole 8 is opened on the intermediate layer wall 2 to weaken the crossflow effect caused by the accumulation of impact cold air between the interlayers.

[0031] In this embodiment, cold air enters from the inner side of the inner wall 3 through the impact hole 7. The cold air impacts the inner sidewall of the outer thin wall 1 and enhances heat exchange. Then, the cold air between the outer thin wall 1 and the middle wall 2 is turbulent due to the turbulence of the first column rib 4, and flows into the interlayer between the middle wall 2 and the inner wall 3 through the return hole 8. Finally, it flows out through the large aspect ratio air film hole 6. The jet fully develops in the hole and forms a cold air cover on the outside of the outer thin wall 1 to isolate the high temperature mainstream.

[0032] See Figure 1 The two ends of the first column rib 4 are integrally formed with the outer thin wall 1 and the middle wall 2, respectively, and the two ends of the second column rib 5 are integrally formed with the middle wall 2 and the inner wall 3, respectively.

[0033] See Figure 1 The air film holes 6 are arranged in N rows, and adjacent air film holes 6 are arranged in a straight or staggered manner.

[0034] Furthermore, let α be the angle between the central axis of the air film pore 6 and the outer thin wall 1, and let α be the value of 25°~35° or 145°~155°.

[0035] Furthermore, let the inner diameter of the air film orifice 6 be d, the length of the air film orifice 6 be l, and the flow spacing be P. x,film The spanwise spacing is P y,film Where d = D, the inclination angle α of the air film pore 6 is 35°, l / D = 6.97, P x,film =12D,P y,film =6D, where the values ​​of flow spacing and spanwise spacing are selected according to the heat load of the outer wall. The greater the heat load, the denser the arrangement and the smaller the spacing.

[0036] Furthermore, let the outer diameter of the first column rib 4 be m, where m = 2D.

[0037] In this embodiment, when the angle between the central axis of the film gas vent 6 and the outer thin wall 1 is 25° to 35°, the jet direction of the film gas vent 6 is a forward jet, the same as the high-temperature mainstream direction; when the angle between the central axis of the film gas vent 6 and the outer thin wall 1 is 145° to 155°, the jet direction of the film gas vent 6 is a reverse jet, opposite to the high-temperature mainstream direction. The jet direction of the film gas vent 6 is determined according to the cold air flow rate and the heat load on the gas side; when the cold air flow rate is small, and the forward jet film adheres well to the wall, a forward jet is used. When the heat load is large, the cold air flow rate needs to be increased, and the forward jet film blows away, a reverse jet is selected to meet the wall adhesion requirements under high blowing ratio conditions.

[0038] See Figure 1 The impact holes 7 are arranged in N rows, and adjacent rows of impact holes 7 are arranged in a straight line or a staggered line.

[0039] Furthermore, let β be the angle between the central axis of the impact hole 7 and the intermediate wall 2 or the inner wall 3, where β = 90°, so that the cold air impacts the inner wall of the outer thin wall 1 perpendicularly.

[0040] Furthermore, let the inner diameter of the impact hole 7 be d′, the length of the impact hole 7 be l′, and the flow spacing be P. x,imp The spanwise spacing is P y,imp Where d=D, l′ / D=3, the length of the impact hole is obtained by its inclination angle and wall thickness; P x,imp =12D,P y,imp =6D, where the values ​​of flow spacing and spanwise spacing are selected according to the heat load of the outer wall. The greater the heat load, the denser the arrangement and the smaller the spacing.

[0041] Furthermore, let the outer diameter of the second column rib 5 be m′, where m′=2D.

[0042] See Figure 1 The reflux holes 8 are provided in N rows, and the adjacent rows of reflux holes 8 are arranged in a straight line or a staggered line.

[0043] See Figure 1 Let the inner diameter of the return orifice 8 be d″ and the flow spacing be P. x,hole The spanwise spacing is P y,hole Where d″=D, P x,hole =12D,P y,hole =6D, where the flow spacing and spanwise spacing are determined based on the parameters of the film pores and the impact pores.

[0044] See Figure 1 The air film holes 6 and the impact holes 7 are arranged alternately in the longitudinal direction, and the return holes 8 are arranged between two air film holes 6 with adjacent flow directions.

[0045] Furthermore, let the flow direction misalignment distance between the air film hole 6 and the impact hole 7 be Δ. imp The flow direction misalignment distance between the air film pore 6 and the return pore 8 is Δ hole , where Δ imp =3D, Δ hole =3D.

[0046] See Figure 1 Let the thickness of the outer thin wall 1 be p, the thickness of the middle wall 2 be p′, and the thickness of the inner wall 3 be p″, where p = p′ = p″ = D; let the distance between the outer thin wall 1 and the middle wall 2 be r, and the distance between the middle wall 2 and the inner wall 3 be r′, where r = 2D and r′ = D.

[0047] In this embodiment, the wall thickness of the outer thin wall 1 and the distance between adjacent layers can be adjusted according to the gas-side heat load and structural strength, and the arrangement and density of the jet holes can also be adjusted according to the gas-side heat load.

[0048] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A plate cooling structure with column rib-jet hole coupling, characterized in that: The plate cooling structure includes an outer thin wall (1), an intermediate wall (2) and an inner wall (3) arranged sequentially and at intervals from the outside to the inside, as well as a first column rib (4) between the outer thin wall (1) and the intermediate wall (2) and a second column rib (5) between the intermediate wall (2) and the inner wall (3); a through hole is opened between the outer thin wall (1) and the intermediate wall (2) through the first column rib (4) to form a gas film hole (6); a through hole is opened between the intermediate wall (2) and the inner wall (3) through the second column rib (5) to form an impact hole (7); a return hole (8) is opened on the intermediate wall (2) for the flow of interlayer gas.

2. The plate cooling structure with column rib-jet hole coupling according to claim 1, characterized in that: The two ends of the first column rib (4) are integrally formed with the outer thin wall (1) and the middle wall (2), respectively, and the two ends of the second column rib (5) are integrally formed with the middle wall (2) and the inner wall (3), respectively.

3. The plate cooling structure with column rib-jet hole coupling according to claim 1, characterized in that: The air film holes (6), impact holes (7) and return holes (8) are arranged in N rows in the flow direction; adjacent rows of air film holes (6) are arranged in a straight or staggered manner; adjacent rows of impact holes (7) are arranged in a straight or staggered manner; adjacent rows of return holes (8) are arranged in a straight or staggered manner; the air film holes (6) and impact holes (7) are arranged alternately in the longitudinal direction, and the return holes (8) are arranged between adjacent rows of air film holes (6).

4. The plate cooling structure with column rib-jet hole coupling according to claim 1, characterized in that: Let α be the angle between the central axis of the air film pore (6) and the outer thin wall (1), and let α be the value of 25°~35° or 145°~155°.

5. The plate cooling structure with column rib-jet hole coupling according to claim 1, characterized in that: Let β be the angle between the central axis of the impact hole (7) and the intermediate wall (2), where β = 90°.

6. The plate cooling structure with column rib-jet hole coupling according to claim 1, characterized in that: Let the inner diameter of the air film hole (6) be d, the inner diameter of the impact hole (7) be d′, and the inner diameter of the return hole (8) be d″, d=d′=d″=D.

7. The plate cooling structure with column rib-jet hole coupling according to claim 1, characterized in that: Let the thickness of the outer thin wall (1) be p, the thickness of the middle wall (2) be p′, and the thickness of the inner wall (3) be p″, then p = p′ = p″ = D.

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