Gas film cooling assembly suitable for turbine blade and gas turbine

Abstract

The embodiment of the invention provides an air film cooling assembly suitable for a turbine blade and a gas turbine. The air film cooling assembly suitable for the turbine blade comprises an air film hole formed in the turbine blade and a flow guide cover arranged on the outer wall face of the turbine blade, a cover cavity with an opening is formed between the flow guide cover and the outer wall face of the turbine blade, the cover cavity is communicated with an outlet of the air film hole, and the flow guide cover is arranged on the outer wall face of the turbine blade. The projection of the inlet of the air film hole, the projection of the outlet of the air film hole and the projection of the opening of the flow guide cover are sequentially arranged. The air film cooling assembly suitable for the turbine blade has a good heat exchange cooling effect.

Description

Technical Field

[0001] The invention relates to the field of gas turbines, and in particular to an air film cooling component suitable for turbine blades and a gas turbine. Background Art

[0002] The turbine blades of gas turbines usually use air film cooling for heat exchange and cooling. In the related art, cylindrical air film holes are set on the turbine blades for the outflow of cold air. However, after the cold air flows out of the cylindrical air film holes, a kidney-shaped vortex rotating in the opposite direction is formed. The kidney-shaped vortex sucks the mainstream hot air flow under the cold air, strengthens the mixing and lifts the cold air away from the wall of the turbine blade, resulting in poor air film cooling effect. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, an embodiment of the present invention provides an air film cooling assembly suitable for turbine blades.

[0005] An embodiment of the present invention further provides a gas turbine having an air film cooling assembly suitable for turbine blades according to the above embodiment.

[0006] The film cooling assembly applicable to turbine blades of the embodiment of the present invention comprises:

[0007] An air film hole is arranged on a turbine blade and a guide cover is arranged on the outer wall surface of the turbine blade. A cover cavity with an opening is formed between the guide cover and the outer wall surface of the turbine blade. The cover cavity is connected with the outlet of the air film hole. On the outer wall surface of the turbine blade, the projection of the inlet of the air film hole, the outlet of the air film hole and the projection of the opening of the guide cover are arranged in sequence.

[0008] In the air film cooling assembly suitable for turbine blades in the embodiment of the present invention, the hood cavity of the guide hood is connected with the outlet of the air film hole, so as to guide the cold air discharged from the air film hole through the inner wall surface of the guide hood and discharge it from the opening of the hood cavity, and guide the mainstream gas such as combustion gas on the outer wall surface of the turbine blade through the outer wall surface of the guide hood, so as to prevent the cold air from directly mixing with the mainstream gas through the jet, thereby reducing the mixing intensity of the cold air and the mainstream gas, and effectively inhibiting the formation of kidney-shaped vortex. At the same time, it can also inhibit the cold air film from detaching from the wall surface, so that the cold air is in contact with the outer wall surface of the turbine blade more, thereby enhancing the wall-adhering effect of the cold air. Therefore, the air film cooling assembly suitable for turbine blades in the embodiment of the present invention has a good heat exchange cooling effect.

[0009] In some embodiments, the air film hole and the cover cavity are both configured as transversely extending strips.

[0010] In some embodiments, on the outer wall surface of the turbine blade, along the direction of medium flow in the cover cavity, the length of the projection of the cover cavity is constant or increases, and the length of the projection of the cover cavity is greater than or equal to the length of the outlet of the air film hole.

[0011] In some embodiments, the air film hole includes a constant section and an expansion section, the constant section forms an entrance of the air film hole on the inner wall surface of the turbine blade, and the expansion section forms an exit of the air film hole on the outer wall surface of the turbine blade, the cross-sectional area of ​​the constant section is constant along the direction of medium flow in the air film hole, and the cross-sectional area of ​​the expansion section increases along the direction of medium flow in the air film hole.

[0012] In some embodiments, the cross-sectional profile of the constant segment includes oppositely disposed elliptical arc segments and oppositely disposed circular arc segments, and the same-direction ends of the oppositely disposed elliptical arc segments are connected to the corresponding circular arc segments.

[0013] In some embodiments, the length L1 of the constant segment and the width W1 of the constant segment satisfy: L1 / W1≥3.

[0014] In some embodiments, the length L2 of the opening of the cover cavity and the width W2 of the opening of the cover cavity satisfy: L2 / W2≥3.

[0015] In some embodiments, the inner wall surface of the cover cavity includes a first inner section and a second inner section, and the first inner section and the second inner section are arranged in sequence along the direction of medium flow in the cover cavity. The first inner section extends along the direction of medium flow in the cover cavity and is inclined in a direction away from the outer wall surface of the turbine blades. The second inner section extends along the direction of medium flow in the cover cavity and is inclined in a direction close to the outer wall surface of the turbine blades.

[0016] In some embodiments, in the longitudinal section of the cover cavity, the cross-section of the first inner segment is an arc line, and the cross-section of the second inner segment is an arc line.

[0017] In some embodiments, the outer wall surface of the cover cavity includes a first outer segment and a second outer segment, and the first outer segment and the second outer segment are sequentially arranged along the direction of flow of the medium in the cover cavity;

[0018] The first outer section and the second outer section both extend along the direction of flow of the medium in the cover cavity and are arranged obliquely in a direction away from the outer wall surface of the turbine blade; or

[0019] The first outer section extends along the direction of medium flow in the cover cavity and is inclined in a direction away from the outer wall surface of the turbine blade. The second outer section extends along the direction of medium flow in the cover cavity and is arranged parallel to the extension direction of the outer wall surface of the turbine blade.

[0020] In some embodiments, in the longitudinal section of the cover cavity, the cross section of the first outer segment is an arc, and the cross section of the second outer segment is a straight line or an arc.

[0021] In some embodiments, the connecting line between the outer wall surface of the cover cavity and the outer wall surface of the turbine blade has a first rounded section, and the connecting line between the inner wall surface of the cover cavity and the outer wall surface of the turbine blade has a second rounded section, and the radius of the first rounded section is smaller than the radius of the second rounded section.

[0022] The gas turbine of the embodiment of the present invention comprises: turbine blades and an air film cooling assembly applicable to the turbine blades as described in any one of the above embodiments.

[0023] The gas turbine according to the embodiment of the present invention is provided with an air film cooling assembly suitable for the turbine blades according to the embodiment of the present invention on the turbine blades, which has a better air film cooling effect, thereby reducing the amount of cooling gas used, reducing the maintenance and replacement frequency of the air film cooling assembly suitable for the turbine blades, and having stronger environmental applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a perspective view of an air film cooling assembly applicable to a turbine blade according to an embodiment of the present invention on a turbine blade;

[0025] Figure 2 is a schematic diagram of an air film cooling assembly applicable to a turbine blade according to an embodiment of the present invention after a guide cover is removed from the turbine blade;

[0026] Figure 3 is a top perspective view of an air film cooling assembly applicable to turbine blades according to an embodiment of the present invention;

[0027] Figure 4 yes Figure 1 A side cross-sectional view of a film cooling assembly for a turbine blade on a turbine blade;

[0028] Figure 5 yes Figure 4 An enlarged schematic diagram of the middle fairing;

[0029] Figure 6 is a perspective view of an air film cooling assembly applicable to turbine blades according to an embodiment of the present invention;

[0030] Figure 7 is a front view of an air film cooling assembly applicable to turbine blades according to an embodiment of the present invention;

[0031] Figure 8 yes Figure 6 Schematic diagram of the cross section of the constant segment.

[0032] Reference numerals:

[0033] 1. Turbine blades;

[0034] 2. Air film hole; 21. Exit; 22. Inlet; 23. Constant section; 231. Elliptical arc section; 232. Circular arc section; 24. Expansion section;

[0035] 3. fairing; 31. first inner section; 32. second inner section; 33. first outer section; 34. second outer section;

[0036] 4. housing cavity; 41. opening;

[0037] 5. The first fillet segment;

[0038] 6. The second rounded corner segment. DETAILED DESCRIPTION

[0039] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0040] Reference below Figure 1-Figure 8 A film cooling assembly and a gas turbine applicable to turbine blades according to an embodiment of the present invention are described.

[0041] like Figure 1-Figure 8 As shown, the film cooling assembly suitable for turbine blades according to the embodiment of the present invention comprises a film hole 2 arranged on the turbine blade 1 and a guide cover 3 arranged on the outer wall surface of the turbine blade 1 .

[0042] A hood cavity 4 having an opening 41 is formed between the guide hood 3 and the outer wall surface of the turbine blade 1, and the hood cavity 4 is connected to the outlet 21 of the air film hole 2. Figure 1-Figure 4 As shown, Figure 1-Figure 4 The turbine blade 1 shown in the figure is a part of the wall of the turbine blade 1. An inner cavity for receiving cold air is provided inside the turbine blade 1. An air film hole 2 is provided on the wall of the turbine blade 1. The air film hole 2 extends from the back to the front and penetrates the wall of the turbine blade 1 along the wall thickness direction of the turbine blade 1. At the same time, the air film hole 2 forms an inlet 22 connected to the inner cavity of the turbine blade 1 on the inner wall surface of the turbine blade 1, and forms an outlet 21 on the outer wall surface of the turbine blade 1, so that the cold air in the inner cavity of the turbine blade 1 is discharged to the outer wall surface of the turbine blade 1 through the air film hole 2 and forms an air film. A protruding air deflector 3 is provided on the outer wall surface of the turbine blade 1. A cover cavity 4 with an opening 41 is formed between the air deflector 3 and the outer wall surface of the turbine blade 1. The cover cavity 4 is connected to the outlet 21 of the air film hole 2. The cold air discharged from the outlet 21 of the air film hole 2 enters the cover cavity 4 and is discharged from the opening 41.

[0043] On the outer wall surface of the turbine blade 1, the projection of the inlet 22 of the air film hole 2, the outlet 21 of the air film hole 2 and the projection of the opening 41 of the air guide cover 3 are arranged in sequence. Figure 3 As shown, in Figure 1 In the horizontal projection plane of the orientation shown, the projection of the inlet 22 of the air film hole 2, the projection of the outlet 21 of the air film hole 2 and the projection of the opening 41 of the air guide cover 3 are arranged in sequence from back to front, and the cold air flows in the direction from back to front (as shown in FIG. Figure 1 and Figure 4 The cooling air flows in the direction A) from the inner cavity of the turbine blade 1 through the inlet 22 into the air film hole 2, then from the air film hole 2 through the outlet 21 into the cover cavity 4, and finally is discharged from the opening 41, thereby ensuring smooth flow of cooling air.

[0044] It should be noted that, on the outer wall of the turbine blade 1, the projections of the outlet 21 of the air film hole 2 and the opening 41 of the air guide cover 3 can be arranged at intervals, can be connected by edges, or can partially overlap. Figure 1 In the horizontal projection plane of the orientation shown, the projection of the outlet 21 of the air film hole 2 and the projection of the opening 41 of the air guide cover 3 can be arranged at intervals, or can be connected by edges, or can partially overlap. Figure 1 In the horizontal projection plane of the shown orientation, the front edge line of the projection of the outlet 21 of the air film hole 2 is connected to the rear edge line of the projection of the opening 41 of the air deflector 3. In other words, the front edge line of the projection of the outlet 21 of the air film hole 2 is collinear with the rear edge line of the projection of the opening 41 of the air deflector 3.

[0045] In the film cooling assembly for turbine blades of the embodiment of the present invention, the hood cavity of the hood is connected to the outlet of the film hole, so that the cold air discharged from the film hole is guided through the inner wall surface of the hood and discharged from the opening of the hood cavity, and the mainstream gas such as combustion gas on the outer wall surface of the turbine blade is guided through the outer wall surface of the hood (the flow direction of the mainstream gas is as follows Figure 1 and Figure 4 Direction B) shown in the figure prevents the cold air from directly mixing with the mainstream gas through the jet, reduces the mixing intensity of the cold air and the mainstream gas, and can effectively inhibit the formation of kidney-shaped vortex. At the same time, it can also inhibit the cold air film from detaching from the wall, so that the cold air is more in contact with the outer wall of the turbine blade, thereby enhancing the wall-adhering effect of the cold air. Therefore, the air film cooling component suitable for turbine blades in the embodiment of the present invention has a good heat exchange cooling effect.

[0046] In some embodiments, the turbine blade 1 is provided with a plurality of rows of air guide covers 3 arranged at intervals along the front-to-back direction, each row of air guide covers 3 includes a plurality of air guide covers 3 arranged at intervals along the left-to-right direction, a cover cavity 4 formed by each air guide cover 3 is connected to the corresponding air film hole 2, and the plurality of air guide covers 3 in two adjacent rows are arranged correspondingly.

[0047] In the direction from back to front, the cold air discharged from the hood cavity 4 of the upstream air guide hood 3 flows forward along the outer wall surface of the turbine blade 1, and then contacts the downstream air guide hood 3 and flows under the guidance of the downstream air guide hood 3, which can effectively prevent the cold air from directly mixing with the mainstream gas through the jet, reduce the mixing intensity of the cold air and the mainstream gas, and at the same time inhibit the cold air film from detaching from the wall surface, so that the cold air can contact more with the outer wall surface of the turbine blade, enhance the wall-adhering effect of the cold air, and also inhibit the formation of kidney-shaped vortex pairs.

[0048] It can be understood that the multiple air guide covers 3 in two adjacent rows are not limited to the corresponding arrangement. In other embodiments, the multiple air guide covers 3 in two adjacent rows are arranged alternately. Compared with the corresponding arrangement of the multiple air guide covers 3 in two adjacent rows, the alternating arrangement of the multiple air guide covers 3 in two adjacent rows can increase the area cooled by the air film to achieve a better cooling effect.

[0049] In some embodiments, the air film hole 2 and the cover cavity 4 are both arranged in a strip shape extending laterally. In other words, the cross-sections of the air film hole 2 and the cover cavity 4 are both strip-shaped. Figure 1-Figure 3 , Figure 6 and Figure 7 The air film hole 2 and the cover cavity 4 extend in the same strip-shaped length direction, both as shown in FIG. Figure 1 Left and right directions shown.

[0050] The cross-sections of the air film holes and the hood cavity are both strip-shaped, which can increase the cross-flow coverage area of ​​the air film, improve the lateral uniformity of the air film, and promote the contact between the cold air and the turbine blades, thereby improving the cooling effect of the turbine blades. At the same time, it can reduce the momentum of the cold air jet, increase the spacing between the kidney-shaped vortex pairs to reduce the induced lift, and effectively inhibit the formation of kidney-shaped vortices. It can also improve the utilization rate of cold air. Compared with the air film holes in the related art, the amount of cold air can be reduced while achieving the same cooling effect.

[0051] In some embodiments, on the outer wall surface of the turbine blade 1, along the direction of medium flow in the cover cavity 4, the length of the projection of the cover cavity 4 is constant or increases, and the length of the projection of the cover cavity 4 is greater than or equal to the length of the outlet 21 of the air film hole 2.

[0052] like Figure 3 and Figure 4As shown, on the outer wall surface of the turbine blade 1, the front end of the guide cover 3 extends forward relative to the outlet 21 of the air film hole 2, so the front end of the projection of the cover cavity 4 extends forward relative to the outlet 21 of the air film hole 2, and the projection of the cover cavity 4, except for the part of the projection of the cover cavity 4 that extends forward relative to the outlet 21 of the air film hole 2, the remaining part of the projection of the cover cavity 4 coincides with the outlet 21 of the air film hole 2. Therefore, along the direction from back to front, the length of the projection of the cover cavity 4 in the left-right direction is always consistent with the length of the outlet 21 of the air film hole 2 in the left-right direction along the front-to-back direction, and both increase along the direction from back to front. In other words, the outlet 21 of the air film hole 2 and the cover cavity 4 are both expanded from back to front.

[0053] This ensures that the cold air in the air film hole 2 smoothly enters the cover cavity 4, flows smoothly along the cover cavity 4, and is finally discharged smoothly from the opening 41. The cold air discharged from the opening 41 is in an expansion shape along the left and right directions, so as to increase the area covered by the cross-flow of the air film, improve the lateral uniformity of the air film, and promote the contact between the cold air and the turbine blades, thereby improving the cooling effect of the turbine blades. At the same time, it can reduce the momentum of the cold air jet, increase the spacing between the kidney-shaped vortex pairs to reduce the induced lift, and effectively inhibit the formation of the kidney-shaped vortex. It can also improve the utilization rate of cold air. Compared with the air film holes in the related art, the amount of cold air can be reduced while achieving the same cooling effect.

[0054] In some embodiments, the air film hole 2 includes a constant section 23 and an expansion section 24. The constant section 23 forms an inlet 22 of the air film hole 2 on the inner wall surface of the turbine blade 1, and the expansion section 24 forms an outlet 21 of the air film hole 2 on the outer wall surface of the turbine blade 1. The cross-sectional area of ​​the constant section 23 is constant along the direction of medium flow in the air film hole 2, and the cross-sectional area of ​​the expansion section 24 increases along the direction of medium flow in the air film hole 2.

[0055] like Figure 1 , Figure 3 , Figure 4 , Figure 6 and Figure 7 As shown, the air film hole 2 includes a constant section 23 and an expansion section 24 connected in sequence from the inlet 22 to the outlet 21. The cross-sectional area of ​​the constant section 23 is constant along the direction of the cold air flowing in the air film hole 2, and the cross-sectional area of ​​the expansion section 24 increases along the direction of the cold air flowing in the air film hole 2. The expansion section 24 can be set to increase the width of the cross section along the direction of the cold air flowing in the air film hole 2, or can be set to increase the length of the cross section along the direction of the cold air flowing in the air film hole 2. It is preferably set to increase both the width and length of the cross section along the direction of the cold air flowing in the air film hole 2.

[0056] It should be noted that the width of the cross section of the expansion section 24 refers to the maximum dimension of the cross section of the expansion section 24 along the front-to-back direction, and the length of the cross section of the expansion section 24 refers to the maximum dimension of the cross section of the expansion section 24 along the left-to-right direction.

[0057] The air film holes are arranged as a constant section and an expansion section connected in sequence so that the cold air is discharged in an expansion form, increasing the cross-flow coverage area of ​​the air film, improving the lateral uniformity of the air film, and promoting the contact between the cold air and the turbine blades, thereby enhancing the cooling effect of the turbine blades. At the same time, it can reduce the momentum of the cold air jet, increase the spacing between the kidney-shaped vortex pairs to reduce the induced lift, effectively inhibit the formation of kidney-shaped vortices, and further form anti-kidney vortex flow, thereby improving the air film cooling efficiency.

[0058] In some embodiments, the cross-sectional profile of the constant segment 23 includes oppositely disposed elliptical arc segments 231 and oppositely disposed circular arc segments 232 , and the same-direction ends of the oppositely disposed elliptical arc segments 231 are connected to the corresponding circular arc segments 232 .

[0059] like Figure 8 As shown, the cross-sectional profile of the constant segment 23 includes two elliptical arc segments 231 arranged opposite to each other in the front-to-back direction and two circular arc segments 232 arranged opposite to each other in the left-to-right direction. The two elliptical arc segments 231 are preferably but not limited to being located on the same ellipse. The diameters of the circles respectively formed by the two circular arc segments 232 are preferably but not limited to being the same. The left end circular arc segment 232 is connected between the left ends of the two elliptical arc segments 231, and the right end circular arc segment 232 is connected between the right ends of the two elliptical arc segments 231.

[0060] The cross-sectional shape of the constant section can avoid the appearance of regions with large curvature changes at the left and right ends of the constant section, thereby reducing the flow loss of cold air in the air film hole and reducing local stress concentration.

[0061] In some embodiments, the length L1 of the constant section 23 and the width W1 of the constant section 23 satisfy: L1 / W1≥3.

[0062] like Figure 8 As shown, the length L1 of the constant section 23 is the maximum dimension of the cross section of the constant section 23 along the left-right direction, the width W1 of the constant section 23 is the maximum dimension of the cross section of the constant section 23 along the front-back direction, L1 / W1≥3, so that the cross section of the constant section 23 is strip-shaped, and then the cross section of the air film hole is strip-shaped, so as to increase the cross-flow coverage area of ​​the air film, improve the lateral uniformity of the air film, promote the contact between the cold air and the turbine blades, thereby improving the cooling effect of the turbine blades, and can also improve the utilization rate of the cold air. Compared with the air film holes in the related technology, the amount of cold air can be reduced while achieving the same cooling effect.

[0063] In some embodiments, the length L2 of the opening 41 of the cover cavity 4 and the width W2 of the opening 41 of the cover cavity 4 satisfy: L2 / W2≥3.

[0064] like Figure 7As shown, the length L2 of the opening 41 of the cover cavity 4 is the maximum dimension of the opening 41 along the left-right direction, the width W2 of the opening 41 of the cover cavity 4 is the maximum dimension of the opening 41 along the up-down direction, L2 / W2≥3, so that the opening 41 of the cover cavity 4 is strip-shaped, so as to increase the cross-flow coverage area of ​​the air film, improve the lateral uniformity of the air film, promote the contact between the cold air and the turbine blades, thereby improving the cooling effect of the turbine blades, and can also improve the utilization rate of the cold air. Compared with the air film holes in the related technology, the amount of cold air can be reduced while achieving the same cooling effect.

[0065] In some embodiments, the inner wall surface of the guide cover 3 includes a first inner section 31 and a second inner section 32, and the first inner section 31 and the second inner section 32 are arranged in sequence along the direction of medium flow in the cover cavity 4. The first inner section 31 extends along the direction of medium flow in the cover cavity 4 and is inclined in the direction away from the outer wall surface of the turbine blade 1. The second inner section 32 extends along the direction of medium flow in the cover cavity 4 and is inclined in the direction close to the outer wall surface of the turbine blade 1.

[0066] like Figure 4 and Figure 5 As shown, the inner wall surface of the air guide 3 includes a first inner section 31 and a second inner section 32 connected in sequence from back to front, and the first inner section 31 is connected between the second inner section 32 and the hole wall surface of the air film hole 2. The first inner section 31 extends from back to front and is in a direction away from the outer wall surface of the turbine blade 1 (such as Figure 5 The second inner section 32 extends from the rear to the front and is arranged in a direction close to the outer wall surface of the turbine blade 1 (as shown in the upward direction). Figure 5 The downward direction as shown) is tilted setting.

[0067] The first inner section and the second inner section cooperate with each other to guide the flow of cold air, ensuring smooth flow of cold air on the one hand, and on the other hand compressing the upward flow path of the cold air through the second inner section, so that it can further flow slightly downward, causing the cold air to flow better against the wall after impacting the outer wall of the turbine blade, thereby improving the impact cooling effect of the cold air near the opening and the air film cooling effect.

[0068] In some embodiments, in the longitudinal section of the cover cavity 4, the cross section of the first inner section 31 is an arc line, and the cross section of the second inner section 32 is an arc line.

[0069] like Figure 5 As shown, in the longitudinal section of the cover cavity 4, the cross section of the first inner section 31 is an arc, and the cross section of the second inner section 32 is an arc, so as to have a better guiding effect on the cold air.

[0070] On any longitudinal section of the cover cavity 4, the distance between the connection point of the first inner section 31 and the second inner section 32 and the outer wall surface of the turbine blade 1 is the maximum value of the distance between the inner wall surface projection and the outer wall surface of the cover cavity 4 on the longitudinal section.

[0071] like Figure 6 and Figure 7 As shown, the inner wall surface of the air deflector 3 is divided into an inner left section, an inner middle section and an inner right section in sequence along the left-right direction. The inner left section is transitionally connected between the inner middle section and the left end hole wall surface of the air film hole 2, and the inner right section is transitionally connected between the inner middle section and the right end hole wall surface of the air film hole 2. Since in the longitudinal section of the cover cavity 4, the cross-section of the first inner section 31 is an arc, and the cross-section of the second inner section 32 is an arc, the parts of the first inner section 31 on the inner left section, the inner middle section and the inner right section are all curved surfaces, and the parts of the second inner section 32 on the inner left section, the inner middle section and the inner right section are all curved surfaces.

[0072] In some embodiments, the outer wall surface of the air guide cover 3 includes a first outer section 33 and a second outer section 34, and the first outer section 33 and the second outer section 34 are sequentially arranged along the direction of the medium flow in the cover cavity 4. The first outer section 33 and the second outer section 34 both extend along the direction of the medium flow in the cover cavity 4, and are arranged obliquely in the direction away from the outer wall surface of the turbine blade 1. Alternatively, the first outer section 33 extends along the direction of the medium flow in the cover cavity 4, and is arranged obliquely in the direction away from the outer wall surface of the turbine blade 1, and the second outer section 34 extends along the direction of the medium flow in the cover cavity 4, and is arranged parallel to the extension direction of the outer wall surface of the turbine blade 1.

[0073] like Figure 5 As shown, the outer wall of the air guide 3 includes a first outer section 33 and a second outer section 34 connected in sequence from the back to the front, and the first outer section 33 is connected between the second outer section 34 and the outer wall of the turbine blade 1. The first outer section 33 extends from the back to the front and is away from the outer wall of the turbine blade 1 (such as Figure 5 The second outer section 34 extends from the rear to the front and is arranged in a direction away from the outer wall surface of the turbine blade 1 (as shown in the upward direction). Figure 5 It is arranged to be inclined (in the upward direction shown in the figure), or to be arranged parallel to the extension direction of the outer wall surface of the turbine blade 1, in other words, to extend in a straight line along the front-rear direction.

[0074] The first outer section and the second outer section cooperate with each other to guide the flow of mainstream gas such as combustion gas, thereby reducing the mixing of mainstream gas and cold air. Meanwhile, the streamlined outer contour design can effectively reduce the aerodynamic loss of the mainstream gas.

[0075] In some embodiments, in the longitudinal section of the cover cavity 4, the cross section of the first outer section 33 is an arc, and the cross section of the second outer section 34 is a straight line.

[0076] like Figure 5As shown, in the longitudinal section of the cover cavity 4, the cross-section of the first outer section 33 is an arc line to reduce the aerodynamic loss of the first outer section 33 as the windward surface to the mainstream gas, and the cross-section of the second outer section 34 is a straight line or an arc line, which can be a slant line or an arc line extending from back to front and tilted upward, or a straight line extending from back to front, preferably an arc line extending from back to front and tilted upward, so as to have smaller aerodynamic losses.

[0077] like Figure 6 and Figure 7 As shown, the outer wall surface of the air guide cover 3 is divided into an outer left section, an outer middle section and an outer right section in sequence along the left-right direction. The outer left section is transitionally connected between the outer middle section and the outer wall surface of the turbine blade 1, and the outer right section is transitionally connected between the outer middle section and the outer wall surface of the turbine blade 1. Since in the longitudinal section of the cover cavity 4, the cross-section of the first outer section 33 is an arc, and the cross-section of the second outer section 34 is a straight line or an arc, the parts of the first outer section 33 on the outer left section, the outer middle section and the outer right section are all curved surfaces, the parts of the second outer section 34 on the outer left section and the outer right section are curved surfaces, and the part on the outer middle section is a plane or a curved surface.

[0078] In some embodiments, the connecting line between the outer wall surface of the cover cavity 4 and the outer wall surface of the turbine blade 1 has a first rounded section 5, and the connecting line between the inner wall surface of the cover cavity 4 and the outer wall surface of the turbine blade 1 has a second rounded section 6, and the radius of the first rounded section 5 is smaller than the radius of the second rounded section 6.

[0079] like Figure 1-Figure 3 As shown, the connecting line between the outer wall surface of the cover cavity 4 and the outer wall surface of the turbine blade 1 includes a left outer section, a right outer section and a rear outer section. The left outer section and the right outer section are straight lines extending in the front-to-back direction, and the rear outer section is a straight line extending in the left-to-right direction. A first fillet section 5 for transition connection is provided between the left outer section and the rear outer section, and another first fillet section 5 for transition connection is provided between the right outer section and the rear outer section.

[0080] The connecting line between the inner wall surface of the cover cavity 4 and the outer wall surface of the turbine blade 1 includes a left inner section, a right inner section and a rear inner section, the rear inner section is a straight line extending in the left-right direction, and the left inner section and the right inner section are both second fillet sections 6 directly connected to the rear inner section, or the left inner section and the right inner section are straight lines extending in the front-back direction, a second fillet section 6 is provided for transition connection between the left inner section and the rear inner section, and another second fillet section 6 is provided for transition connection between the right inner section and the rear inner section. Preferably, the left inner section and the right inner section are both second fillet sections 6 directly connected to the rear inner section.

[0081] The radius of the first fillet section 5 is smaller than the radius of the second fillet section 6. The cold air is ejected from the opening in a lateral expansion manner, which promotes the lateral expansion of the cold air, increases the area covered by the air film cross flow, and can inhibit the formation of kidney-shaped vortex pairs, and further form anti-kidney vortex flow, thereby improving the air film cooling efficiency.

[0082] An embodiment of the present invention further provides a gas turbine.

[0083] The gas turbine according to the embodiment of the present invention comprises a turbine blade and an air film cooling assembly suitable for the turbine blade according to the embodiment of the present invention.

[0084] The gas turbine according to the embodiment of the present invention is provided with an air film cooling assembly suitable for the turbine blades according to the embodiment of the present invention on the turbine blades, which has a better air film cooling effect, thereby reducing the amount of cooling gas used, reducing the maintenance and replacement frequency of the air film cooling assembly suitable for the turbine blades, and having stronger environmental applicability.

[0085] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0086] In addition, the terms "first" and "second" are only used for distinction, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0087] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0088] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0089] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0090] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A film cooling assembly suitable for turbine blades, characterized in that: include: An air film hole (2) is provided on a turbine blade (1) and a guide cover (3) is provided on the outer wall surface of the turbine blade (1); a cover cavity (4) having an opening (41) is formed between the guide cover (3) and the outer wall surface of the turbine blade (1); the cover cavity (4) is connected to the outlet (21) of the air film hole (2); and on the outer wall surface of the turbine blade (1), a projection of the inlet (22) of the air film hole (2), the outlet (21) of the air film hole (2) and the projection of the opening (41) of the guide cover (3) are arranged in sequence.

2. The film cooling assembly for turbine blades according to claim 1, characterized in that: The air film holes (2) and the cover cavity (4) are both arranged in the shape of transversely extending strips.

3. The film cooling assembly for turbine blades according to claim 2, characterized in that: On the outer wall surface of the turbine blade (1), along the direction of flow of the medium in the cover cavity (4), the projected length of the cover cavity (4) is constant or increases, and the projected length of the cover cavity (4) is greater than or equal to the length of the outlet (21) of the air film hole (2).

4. The film cooling assembly for turbine blades according to claim 1 or 2, characterized in that: The air film hole (2) comprises a constant section (23) and an expansion section (24); the constant section (23) forms an inlet (22) of the air film hole (2) on the inner wall surface of the turbine blade (1); the expansion section (24) forms an outlet (21) of the air film hole (2) on the outer wall surface of the turbine blade (1); the cross-sectional area of ​​the constant section (23) is constant along the direction of flow of the medium in the air film hole (2); and the cross-sectional area of ​​the expansion section (24) increases along the direction of flow of the medium in the air film hole (2).

5. The film cooling assembly for turbine blades according to claim 4, characterized in that: The cross-sectional profile of the constant segment (23) comprises oppositely disposed elliptical arc segments (231) and oppositely disposed circular arc segments (232), and the same-direction ends of the oppositely disposed elliptical arc segments (231) are connected to the corresponding circular arc segments (232).

6. The film cooling assembly for turbine blades according to claim 4, characterized in that: The length L1 of the constant section (23) and the width W1 of the constant section (23) satisfy: L1 / W1≥3.

7. The film cooling assembly for turbine blades according to claim 2, characterized in that: The length L2 of the opening (41) of the cover cavity (4) and the width W2 of the opening (41) of the cover cavity (4) satisfy: L2 / W2≥3.

8. The film cooling assembly for turbine blades according to claim 1, characterized in that: The inner wall surface of the deflector (3) comprises a first inner section (31) and a second inner section (32), wherein the first inner section (31) and the second inner section (32) are arranged in sequence along the direction of flow of the medium in the cover cavity (4), wherein the first inner section (31) extends along the direction of flow of the medium in the cover cavity (4) and is arranged at an angle in a direction away from the outer wall surface of the turbine blade (1), and the second inner section (32) extends along the direction of flow of the medium in the cover cavity (4) and is arranged at an angle in a direction close to the outer wall surface of the turbine blade (1).

9. The film cooling assembly for turbine blades according to claim 8, characterized in that: In the longitudinal section of the cover cavity (4), the cross section of the first inner section (31) is an arc line, and the cross section of the second inner section (32) is an arc line.

10. The film cooling assembly for turbine blades according to claim 1, characterized in that: The outer wall surface of the flow guide cover (3) comprises a first outer section (33) and a second outer section (34), and the first outer section (33) and the second outer section (34) are arranged in sequence along the direction of flow of the medium in the cover cavity (4); The first outer section (33) and the second outer section (34) both extend in the direction of flow of the medium in the cover cavity (4), and are arranged obliquely in a direction away from the outer wall surface of the turbine blade (1); or The first outer section (33) extends along the direction of medium flow in the cover cavity (4) and is arranged obliquely in a direction away from the outer wall surface of the turbine blade (1); the second outer section (34) extends along the direction of medium flow in the cover cavity (4) and is arranged parallel to the extension direction of the outer wall surface of the turbine blade (1).

11. The film cooling assembly for turbine blades according to claim 10, characterized in that: In the longitudinal section of the cover cavity (4), the cross section of the first outer section (33) is an arc, and the cross section of the second outer section (34) is a straight line or an arc.

12. The film cooling assembly for turbine blades according to claim 1, characterized in that: The connecting line between the outer wall surface of the cover cavity (4) and the outer wall surface of the turbine blade (1) has a first rounded corner section (5), and the connecting line between the inner wall surface of the cover cavity (4) and the outer wall surface of the turbine blade (1) has a second rounded corner section (6), and the radius of the first rounded corner section (5) is smaller than the radius of the second rounded corner section (6).

13. A gas turbine, characterized in that: include: A turbine blade (1) and a film cooling assembly suitable for a turbine blade as claimed in any one of claims 1 to 12.

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