Novel groove air film hole with arc-shaped platform and turbine blade

Abstract

The invention provides a novel groove air film hole with an arc-shaped platform and a turbine blade, and the novel groove air film hole with the arc-shaped platform comprises a solid wall surface which is provided with discrete cylindrical air film holes; and the thermal barrier coating is arranged on the solid wall surface, a groove structure is arranged on the thermal barrier coating, and the groove structure corresponds to the outlet position of the cylindrical air film hole. According to the invention, the outflow amount of cold air can be effectively reduced, the cold air is induced to fully develop in the groove structure, and the air film cooling efficiency is obviously improved. And meanwhile, the shape of the groove structure can be formed through the thermal barrier coating, the strength of the blade base body cannot be affected, and wide application prospects are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of cooling of gas turbine blades, and in particular to a novel grooved air film hole with an arc-shaped platform and a turbine blade. Background Art

[0002] In order to further improve the cycle thermal efficiency and output power of gas turbine engines, the temperature before the gas turbine continues to increase, which leads to a significant increase in the thermal load of the turbine blades. Film cooling is a widely used cooling technology in air-cooled turbine blades. Early film cooling mostly selected cylindrical holes that are easy to process. However, with the increase in the thermal load of turbine blades, the problem of insufficient cooling capacity of traditional cylindrical holes has become increasingly prominent. In the actual application of cylindrical holes, as the amount of cold air increases, the jet momentum increases accordingly, resulting in the inability of cold air to form a good adhesion on the blade surface, causing cooling failure. In order to further improve the efficiency of film cooling, researchers have made a lot of optimization designs on the shape of film holes, including groove holes, contraction-expansion holes, slot holes, crescent holes, cat ear holes, fan-shaped holes, etc. Among them, the groove hole is one of the hole types with development potential. It sets a groove at the outlet of the cylindrical hole, so that the cold air jet first diffuses in the groove, and then flows out of the groove shape, reducing the outlet momentum of the cold air jet, thereby improving the coverage effect of the cold air. The design idea of ​​the groove hole shows that the groove shape has a significant impact on the air film cooling effect of the groove hole, so it is necessary to improve the shape of the groove hole. Summary of the invention

[0003] In view of this, the embodiments of the present specification provide a novel groove film hole with an arc-shaped platform and a turbine blade to achieve the purpose of improving the film cooling efficiency.

[0004] The embodiments of this specification provide the following technical solutions: a new type of grooved air film hole with an arc-shaped platform, comprising: a solid wall surface, on which discrete cylindrical air film holes are arranged; a thermal barrier coating, which is arranged on the solid wall surface, and a groove structure is arranged on the thermal barrier coating, and the groove structure corresponds to the outlet position of the cylindrical air film hole.

[0005] Furthermore, the groove structure includes: a platform area corresponding to the outlet position of the cylindrical air film hole, the platform area has an end surface facing the outlet of the cylindrical air film hole; two recessed areas, both of which are arc-shaped structures, and the two recessed areas are symmetrically arranged on both sides of the platform area.

[0006] Furthermore, discrete semicircular grooves are provided on the end surface of the platform area.

[0007] Furthermore, the platform area and one recessed area form a groove unit, the groove structure includes a plurality of groove units, and the platform areas and recessed areas of adjacent groove units are connected.

[0008] Furthermore, there are multiple cylindrical air film holes, and each of the multiple cylindrical air film holes corresponds one-to-one to the platform areas of the multiple groove units.

[0009] Furthermore, the diameter of the cylindrical air film hole is D, the length of the cylindrical air film hole is L, wherein 2D≤L≤6D; the flow direction inclination angle between the cylindrical air film hole and the horizontal plane is α, wherein 30°≤α≤90°; the flow direction length of the cylindrical air film hole outlet is W1, wherein 1D≤W1≤2D.

[0010] Furthermore, the distance between the axes of two adjacent cylindrical air film holes is 2D-5D.

[0011] Furthermore, the span width of the platform area is S2, wherein 0.5D≤S2≤1.5D; the flow lengths of the platform area and the depression area are both W2, wherein 0.5D≤W2≤1.5D; the span width of the depression area is S1, wherein 0.5D≤S1≤1.5D, and S1=S2.

[0012] Furthermore, the diameter of the discrete semicircular groove is R1, wherein 0.05D≤R1≤0.15D; the spacing between two adjacent discrete semicircular grooves is P, wherein 0.05D≤P≤0.15D; and the height of the discrete semicircular groove is H, wherein 0.5D≤H≤1.5D.

[0013] The present invention also provides a turbine blade, comprising the novel groove air film hole with an arc-shaped platform.

[0014] Compared with the prior art, the beneficial effects achieved by at least one of the above technical solutions adopted in the embodiments of this specification include at least: the present invention can effectively reduce the outflow momentum of cold air, induce the cold air to fully develop in the groove, and significantly improve the film cooling efficiency. At the same time, the shape of the groove structure can be formed by a thermal barrier coating, which will not affect the strength of the blade substrate and has a wide range of application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a three-dimensional schematic diagram of a novel groove air film hole with an arc-shaped platform of the present invention;

[0017] Figure 2 It is a top view of the novel groove air film hole with arc-shaped platform of the present invention;

[0018] Figure 3 It is a front view of the novel groove air film hole with arc-shaped platform of the present invention;

[0019] Figure 4 This is a unit structure diagram of a novel groove air film hole with an arc-shaped platform of the present invention;

[0020] Figure 5 It is a top view of the novel groove air film hole unit structure with an arc-shaped platform of the present invention;

[0021] Figure 6 It is a left view of the novel groove air film hole unit structure with an arc-shaped platform of the present invention;

[0022] Figure 7 This is a comparison chart of the implementation effects;

[0023] Figure 8 This is a diagram of the average cooling efficiency in the span direction of the present invention and the traditional groove hole at different blowing ratios;

[0024] Fig. 9 This is a diagram of the average cooling efficiency of the surface of the present invention and the traditional groove hole at different blowing ratios.

[0025] The reference numerals in the figure are: 1. thermal barrier coating; 2. solid wall; 3. cylindrical air film hole; 4. groove structure; 5. platform area; 6. recessed area; 7. discrete semicircular groove. DETAILED DESCRIPTION

[0026] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0027] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0028] like Figures 1 to 6 As shown, an embodiment of the present invention provides a novel groove film hole with an arc platform, comprising: a solid wall surface 2 and a thermal barrier coating 1. The solid wall surface 2 is provided with discrete cylindrical film holes 3; the thermal barrier coating 1 is provided on the solid wall surface 2, and a groove structure 4 is provided on the thermal barrier coating 1, and the groove structure 4 corresponds to the outlet position of the cylindrical film hole 3.

[0029] The embodiment of the present invention can effectively reduce the outflow momentum of cold air, induce the cold air to fully develop in the groove structure 4, and significantly improve the air film cooling efficiency. At the same time, the shape of the groove structure 4 can be formed by a thermal barrier coating, which will not affect the strength of the blade substrate and has a wide range of application prospects.

[0030] The groove structure 4 includes a platform area 5 and two recessed areas 6. The platform area 5 corresponds to the outlet position of the cylindrical air film hole 3, and the platform area 5 has an end surface facing the outlet of the cylindrical air film hole 3; the two recessed areas 6 are both arc-shaped structures, and the two recessed areas 6 are symmetrically arranged on both sides of the platform area 5.

[0031] A platform area 5 and two recessed areas 6 are arranged at the downstream position of the cylindrical air film hole 3, and are directly opposite to the position of the cylindrical air film hole 3, which can be used to reduce the outflow momentum of cold air. At the same time, the recessed areas 6 are located on both sides of the platform area 5 and present an arc structure, which is used to induce cold air to form a reflux in the groove structure 4, thereby achieving full development of cold air in the groove structure 4.

[0032] Preferably, a discrete semicircular groove 7 is provided on the end surface of the platform area 5. The discrete semicircular groove 7 can perform secondary crushing on the outflow of cold air, further reducing the speed of the cold air.

[0033] Preferably, the platform area 5 and a recessed area 6 form a groove unit, the groove structure 4 includes a plurality of groove units, and the platform areas 5 of adjacent groove units are connected to the recessed areas 6. There are also a plurality of cylindrical air film holes 3, and the plurality of cylindrical air film holes 3 correspond one-to-one to the platform areas 5 of the plurality of groove units.

[0034] The provision of multiple groove units and multiple cylindrical air film holes 3 can simultaneously increase the cooling efficiency of the overall device, and the specific number of settings can be selected according to the requirements of different cooling effects. The multiple groove units and multiple cylindrical air film holes 3 can be placed in a single row or in multiple rows, which is not limited here.

[0035] The specific structural parameters are as follows:

[0036] The diameter of the cylindrical air film hole 3 is D, and D is 0.45-1.5 mm. The length of the cylindrical air film hole 3 is L, where 2D≤L≤6D. The flow direction inclination angle between the cylindrical air film hole 3 and the horizontal plane is α, where 30°≤α≤90°. The flow direction length of the outlet of the cylindrical air film hole 3 is W1, where 1D≤W1≤2D. The distance between the axes of two adjacent cylindrical air film holes 3 is 2D-5D.

[0037] The span width of the platform area 5 is S2, wherein 0.5D≤S2≤1.5D; the flow lengths of the platform area 5 and the recessed area 6 are both W2, wherein 0.5D≤W2≤1.5D; the span width of the recessed area 6 is S1, wherein 0.5D≤S1≤1.5D, and S1=S2.

[0038] The diameter of the discrete semicircular groove 7 is R1, wherein 0.05D≤R1≤0.15D; the spacing between two adjacent discrete semicircular grooves 7 is P, wherein 0.05D≤P≤0.15D; and the height of the discrete semicircular groove 7 is H, wherein 0.5D≤H≤1.5D.

[0039] like Figure 7 As shown, the upper part is a schematic diagram of the air film cooling effect at the cold air outlet of a new type of groove air film hole with an arc-shaped platform in an embodiment of the present invention, and the lower part is a schematic diagram of the air film cooling effect at the cold air outlet of a traditional groove hole. The depth of the color represents the cooling efficiency of the air film. The lighter the color, the greater the air film cooling efficiency, and the darker the color, the lower the air film cooling efficiency. From the comparison of the upper and lower figures, it can be seen that compared with the traditional groove hole, the new groove air film hole structure with an arc-shaped platform increases the extensional coverage area of ​​the cold air, effectively reduces the outflow momentum of the cold air, and greatly improves the air film cooling efficiency.

[0040] Figure 7 The film cooling structure parameters used in the test are as follows: the diameter D of the cylindrical film hole 3 is 1.0 mm, the length L of the cylindrical film hole 3 is 6D, the flow inclination angle α is 30°, the lateral hole spacing between adjacent cylindrical film holes 3 is 3D, and the groove depth H is 1D. The span width S2 of the platform area 5 is 1D, the diameter R1 of the discrete semicircular groove 7 on the platform area 5 is 0.1D, the groove spacing P is 0.1D, and the height H of the discrete semicircular groove 7 is 1D. In addition, along the flow direction of the film hole, the flow position W2 occupied by the recessed area 6 and the platform area 5 is 1D, and the span spacing S1 and S3 are 1D. The working conditions used in the numerical simulation are as follows: the mainstream velocity is 20m / s, the mainstream turbulence Tu=1%, the cold air to mainstream density ratio DR=1.5, and the blowing ratios are 0.5, 1.0, 1.5 and 2.0 respectively.

[0041] Figure 8 and Fig. 9 The span-wise average and area-average air film cooling effectiveness of the traditional groove hole structure and the new groove hole structure of the present invention are compared. It can be found that compared with the traditional groove hole structure, the present invention provides a new groove air film hole cooling structure with an arc platform, and the air film cooling efficiency is significantly improved under different blowing ratio conditions, which fully demonstrates the superiority of this patent.

[0042] The present invention also provides a turbine blade, comprising the novel groove air film hole with an arc-shaped platform.

[0043] This embodiment has the following beneficial effects:

[0044] 1. The platform area is directly opposite to the outlet of the air film hole, which is used to reduce the momentum of the cold air outflow. At the same time, discrete semicircular grooves are set on the surface of the platform to perform secondary crushing on the cold air outflow and further reduce the cold air speed.

[0045] 2. The recessed area is located on both sides of the platform area and presents an arc-shaped structure, which is used to induce cold air to form a reflux in the groove, thereby achieving full development of cold air in the groove.

[0046] 3. The groove structure can be formed by thermal barrier coating, which has low processing difficulty. It will not affect the strength of the blade substrate while greatly improving the air film cooling efficiency.

[0047] The above is only a specific embodiment of the present invention, and cannot be used to limit the scope of the invention. Therefore, the replacement of equivalent components, or equivalent changes and modifications made according to the scope of protection of the patent of the present invention, should still fall within the scope of this patent. In addition, the technical features of the present invention can be freely combined with each other, with each other, and with each other.

Claims

1. A new type of groove air film hole with an arc platform, characterized in that: include: A solid wall surface (2) is provided with discrete cylindrical air film holes (3); A thermal barrier coating (1) is arranged on a solid wall surface (2), and a groove structure (4) is arranged on the thermal barrier coating (1), wherein the groove structure (4) corresponds to the outlet position of a cylindrical air film hole (3).

2. The novel groove air film hole with arc platform according to claim 1 is characterized in that: The groove structure (4) comprises: A platform area (5) corresponding to the outlet position of the cylindrical air film hole (3), and the platform area (5) has an end surface facing the outlet of the cylindrical air film hole (3); The two recessed areas (6) are both in an arc-shaped structure, and the two recessed areas (6) are symmetrically arranged on both sides of the platform area (5).

3. The novel groove air film hole with arc platform according to claim 2 is characterized in that: Discrete semicircular grooves (7) are provided on the end surface of the platform area (5).

4. The novel groove air film hole with arc platform according to claim 3 is characterized in that: The platform area (5) and a recessed area (6) form a groove unit, the groove structure (4) comprises a plurality of the groove units, and the platform areas (5) and recessed areas (6) of adjacent groove units are connected.

5. The novel groove air film hole with arc-shaped platform according to claim 4 is characterized in that: There are also a plurality of cylindrical air film holes (3), and each of the plurality of cylindrical air film holes (3) corresponds one-to-one to the platform areas (5) of the plurality of groove units.

6. The novel groove air film hole with arc platform according to claim 5 is characterized in that: The diameter of the cylindrical air film hole (3) is D, and the length of the cylindrical air film hole (3) is L, wherein 2D≤L≤6D; the flow direction inclination angle between the cylindrical air film hole (3) and the horizontal plane is α, wherein 30°≤α≤90°; and the flow direction length of the outlet of the cylindrical air film hole (3) is W1, wherein 1D≤W1≤2D.

7. The novel groove air film hole with arc platform according to claim 6 is characterized in that: The distance between the axes of two adjacent cylindrical air film holes (3) is 2D-5D.

8. The novel groove air film hole with arc-shaped platform according to claim 7 is characterized in that: The span width of the platform area (5) is S2, wherein 0.5D≤S2≤1.5D; the flow lengths of the platform area (5) and the recessed area (6) are both W2, wherein 0.5D≤W2≤1.5D; the span width of the recessed area (6) is S1, wherein 0.5D≤S1≤1.5D, and S1=S2.

9. The novel groove air film hole with arc platform according to claim 8 is characterized in that: The diameter of the discrete semicircular groove (7) is R1, wherein 0.05D≤R1≤0.15D; the distance between two adjacent discrete semicircular grooves (7) is P, wherein 0.05D≤P≤0.15D; and the height of the discrete semicircular groove (7) is H, wherein 0.5D≤H≤1.5D.

10. A turbine blade, comprising a novel grooved air film hole with an arc-shaped platform, characterized in that: The novel grooved air film hole with an arc-shaped platform is the novel grooved air film hole with an arc-shaped platform as described in any one of claims 1 to 9.

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