Film cooling assembly for a turbine blade and a gas turbine

Abstract

The turbine blade air film cooling assembly and the gas turbine are suitable for turbine blades. The turbine blade air film cooling assembly comprises an air film hole arranged on a turbine blade and a flow guide cover arranged on an outer wall surface of the turbine blade. The flow guide cover and the outer wall surface of the turbine blade form a cover cavity with an opening. The cover cavity is in communication with an outlet of the air film hole. On the outer wall surface of the turbine blade, a projection of an inlet of the air film hole, the outlet of the air film hole and a projection of the opening of the flow guide cover are arranged in sequence. The turbine blade air film cooling assembly has good heat exchange and cooling effects.

Description

Technical Field

[0001] This invention relates to the field of gas turbines, and more specifically to a film cooling assembly for turbine blades and a gas turbine. Background Technology

[0002] Gas turbine blades typically employ film cooling for heat exchange and temperature reduction. Related technologies involve setting cylindrical film cooling orifices on the turbine blades for cold air to exit. However, after the cold air exits through these orifices, it forms a counter-rotating kidney-shaped vortex. This kidney-shaped vortex draws the mainstream hot air flow downwards, intensifying mixing and causing the cold air to rise and detach from the turbine blade wall, resulting in poor film cooling performance. Summary of the Invention

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

[0004] Therefore, embodiments of the present invention propose a film cooling assembly suitable for turbine blades.

[0005] Embodiments of the present invention also propose a gas turbine having a film cooling assembly for turbine blades as described above.

[0006] The film cooling assembly for turbine blades according to embodiments of the present invention includes:

[0007] A film cooling orifice is provided on the turbine blade and a flow guide is provided on the outer wall surface of the turbine blade. An open cavity is formed between the flow guide and the outer wall surface of the turbine blade. The cavity is connected to the outlet of the film cooling orifice. On the outer wall surface of the turbine blade, the projections of the inlet of the film cooling orifice, the outlet of the film cooling orifice, and the opening of the flow guide are arranged in sequence.

[0008] The film cooling assembly for turbine blades according to embodiments of the present invention has a shroud cavity connected to the outlet of the film cooling hole. The shroud guides the cooled air discharged from the film cooling hole through the inner wall surface of the shroud and discharges it through the opening of the shroud cavity. The outer wall surface of the shroud guides the mainstream gas, such as combustion gas, from the outer wall surface of the turbine blade, preventing the cooled air from directly mixing with the mainstream gas through the jet. This reduces the mixing intensity of the cooled air and the mainstream gas, effectively suppressing the formation of kidney-shaped vortices. Simultaneously, it also suppresses the cooling air film from detaching from the wall surface, allowing the cooled air to contact the outer wall surface of the turbine blade more frequently, enhancing the cooling air's adhesion effect. Therefore, the film cooling assembly for turbine blades according to embodiments of the present invention has good heat exchange and cooling effects.

[0009] In some embodiments, both the air film vent and the hood cavity are configured as laterally extending strips.

[0010] In some embodiments, on the outer wall surface of the turbine blade, along the direction of medium flow within the shroud cavity, the length of the projected length of the shroud cavity is constant or increases, and the length of the projected length of the shroud cavity is greater than or equal to the length of the outlet of the film gas vent.

[0011] In some embodiments, the film gas vent includes a constant section and an expanding section. The constant section forms the inlet of the film gas vent on the inner wall surface of the turbine blade, and the expanding section forms the outlet of the film gas vent 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 within the film gas vent, and the cross-sectional area of ​​the expanding section increases along the direction of medium flow within the film gas vent.

[0012] In some embodiments, the cross-sectional profile of the constant segment includes elliptical arc segments and circular arc segments arranged opposite each other, with the corresponding circular arc segments connected between the same-direction ends of the elliptical 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 hood cavity and the width W2 of the opening of the hood cavity satisfy: L2 / W2≥3.

[0015] In some embodiments, the inner wall of the shroud includes a first inner section and a second inner section, the first inner section and the second inner section being arranged sequentially along the direction of medium flow in the shroud, the first inner section extending along the direction of medium flow in the shroud and inclined along the direction away from the outer wall of the turbine blade, and the second inner section extending along the direction of medium flow in the shroud and inclined along the direction close to the outer wall of the turbine blade.

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

[0017] In some embodiments, the outer wall of the shroud cavity includes a first outer section and a second outer section, wherein the first outer section and the second outer section are arranged sequentially along the direction of medium flow within the shroud cavity;

[0018] Both the first outer section and the second outer section extend along the direction of medium flow within the shroud cavity and are inclined away from the outer wall surface of the turbine blade; or

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

[0020] In some embodiments, in the longitudinal section of the shroud 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 line connecting the outer wall of the shroud cavity and the outer wall of the turbine blade has a first rounded corner segment, and the line connecting the inner wall of the shroud cavity and the outer wall of the turbine blade has a second rounded corner segment, wherein the radius of the first rounded corner segment is smaller than the radius of the second rounded corner segment.

[0022] The gas turbine of this invention includes: turbine blades and a film cooling assembly for turbine blades as described in any of the above embodiments.

[0023] The gas turbine of this invention has a film cooling assembly suitable for turbine blades installed on the turbine blades, which has a better film cooling effect, thereby reducing the amount of cooling gas used, reducing the maintenance and replacement frequency of the film cooling assembly suitable for turbine blades, and making it more environmentally adaptable. Attached Figure Description

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

[0025] Figure 2 This is a schematic diagram of the film cooling assembly for turbine blades according to an embodiment of the present invention after the shroud has been removed from the turbine blade;

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

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

[0028] Figure 5 yes Figure 4 Enlarged schematic diagram of the central fairing;

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

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

[0031] Figure 8 yes Figure 6 A schematic diagram of the cross-section of the constant section.

[0032] Figure label:

[0033] 1. Turbine blades;

[0034] 2. Film air vent; 21. Outlet; 22. Inlet; 23. Constant section; 231. Elliptical arc segment; 232. Circular arc segment; 24. Expansion section;

[0035] 3. Radiator fairing; 31. First inner section; 32. Second inner section; 33. First outer section; 34. Second outer section;

[0036] 4. Cover cavity; 41. Opening;

[0037] 5. First rounded corner segment;

[0038] 6. Second rounded corner segment. Detailed Implementation

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

[0040] The following is for reference. Figures 1-8 A film cooling assembly and a gas turbine suitable for turbine blades according to embodiments of the present invention are described.

[0041] like Figures 1-8 As shown, the film cooling assembly for turbine blades in this embodiment of the invention includes a film cooling hole 2 disposed on the turbine blade 1 and a flow guide shroud 3 disposed on the outer wall surface of the turbine blade 1.

[0042] A cavity 4 with an opening 41 is formed between the shroud 3 and the outer wall surface of the turbine blade 1, and the cavity 4 communicates with the outlet 21 of the film gas vent 2. Specifically, as shown... Figures 1-4 As shown, Figures 1-4 The turbine blade 1 shown is part of the wall of the turbine blade 1. The interior of the turbine blade 1 has an inner cavity for receiving cold air. The wall of the turbine blade 1 has a film gas hole 2, which extends from back to front and penetrates the wall of the turbine blade 1 along the wall thickness direction. At the same time, the film gas hole 2 forms an inlet 22 on the inner wall surface of the turbine blade 1, communicating with the inner cavity of the turbine blade 1, and 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 through the film gas hole 2 to the outer wall surface of the turbine blade 1 and forms a film gas. The outer wall surface of the turbine blade 1 has a protruding guide shroud 3, which forms a shroud cavity 4 with an opening 41 between the guide shroud 3 and the outer wall surface of the turbine blade 1. The shroud cavity 4 communicates with the outlet 21 of the film gas hole 2. The cold air discharged from the outlet 21 of the film gas hole 2 enters the shroud cavity 4 and is discharged through the opening 41.

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

[0044] It should be noted that on the outer wall surface of the turbine blade 1, the projections of the outlet 21 of the film cooling vent 2 and the opening 41 of the shroud 3 can be arranged alternately, connected by edges, or partially overlap. In other words, in the case of... Figure 1 In the horizontal projection plane shown, the projections of the outlet 21 of the air film vent 2 and the opening 41 of the guide shroud 3 can be arranged alternately, connected by edges, or partially overlap. Preferably, in the case of... Figure 1 In the horizontal projection plane shown, the front edge of the projection of the outlet 21 of the air film hole 2 and the rear edge of the projection of the opening 41 of the deflector 3 are connected. In other words, the front edge of the projection of the outlet 21 of the air film hole 2 and the rear edge of the projection of the opening 41 of the deflector 3 are collinear.

[0045] The film cooling assembly for turbine blades according to embodiments of the present invention has a shroud cavity connected to the outlet of the film cooling orifice, so as to guide the cooled air discharged from the film cooling orifice through the inner wall surface of the shroud and discharge it through the opening of the shroud cavity, and guide the mainstream gas such as combustion gas on the outer wall surface of the turbine blade (the flow direction of the mainstream gas is as follows) through the outer wall surface of the shroud. Figure 1 and Figure 4 As shown in direction B), the cold air is prevented from directly mixing with the mainstream gas through the jet, reducing the mixing intensity of the cold air and the mainstream gas. This can effectively suppress the formation of kidney-shaped vortices and also suppress the cold air film from detaching from the wall surface, allowing the cold air to contact the outer wall surface of the turbine blade more, thus enhancing the wall adhesion effect of the cold air. Therefore, the film cooling assembly for turbine blades in this embodiment of the invention has a good heat exchange and cooling effect.

[0046] In some embodiments, the turbine blade 1 is provided with multiple rows of guide shrouds 3 arranged at intervals in the front-back direction. Each row of guide shrouds 3 includes multiple guide shrouds 3 arranged at intervals in the left-right direction. The shroud cavity 4 formed by each guide shroud 3 is connected to the corresponding air film hole 2. Multiple guide shrouds 3 in two adjacent rows are arranged accordingly.

[0047] Along the direction from back to front, the cold air discharged from the cavity 4 of the upstream guide shroud 3 flows forward along the outer wall of the turbine blade 1, and then contacts the downstream guide shroud 3. Under the guidance of the downstream guide shroud 3, it flows, 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 suppress the cold air film from detaching from the wall surface, so that the cold air contacts the outer wall surface of the turbine blade more, enhances the wall adhesion effect of the cold air, and also suppresses the formation of kidney-shaped vortices.

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

[0049] In some embodiments, both the air film aperture 2 and the shroud cavity 4 are configured as laterally extending strips. In other words, the cross-sections of both the air film aperture 2 and the shroud cavity 4 are strip-shaped, such as... Figures 1-3 , Figure 6 and Figure 7 As shown. The air film vent 2 and the hood cavity 4 extend in a strip-like shape with the same length direction, both as shown. Figure 1 The left and right directions are shown.

[0050] The strip-shaped cross-sections of both the film cooling orifice and the shroud cavity increase the area covered by the crossflow of the film cooling system, improve the lateral uniformity of the film cooling system, and promote contact between the cooled air and the turbine blades, thereby enhancing the cooling effect of the turbine blades. Simultaneously, it reduces the jet velocity of the cooled air, increases the spacing between the kidney-shaped vortex pairs to reduce induced lift, and effectively suppresses the formation of kidney-shaped vortices. It also improves the utilization rate of cooled air. Compared to film cooling orifices in related technologies, it reduces the amount of cooled air required to achieve 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 shroud cavity 4, the length of the projection of the shroud cavity 4 is constant or increases, and the length of the projection of the shroud cavity 4 is greater than or equal to the length of the outlet 21 of the film gas hole 2.

[0052] like Figure 3 and Figure 4As shown, on the outer wall of the turbine blade 1, the front end of the shroud 3 extends forward relative to the outlet 21 of the film gas aperture 2. Therefore, the front end of the projection of the shroud cavity 4 extends forward relative to the outlet 21 of the film gas aperture 2. Except for the part that extends forward relative to the outlet 21 of the film gas aperture 2, the remaining part of the projection of the shroud cavity 4 coincides with the outlet 21 of the film gas aperture 2. Therefore, along the rear-to-front direction, the length of the projection of the shroud cavity 4 in the left-right direction is always consistent with the length of the outlet 21 of the film gas aperture 2 in the left-right direction along the front-to-back direction, and both increase along the rear-to-front direction. In other words, both the outlet 21 of the film gas aperture 2 and the shroud cavity 4 are flared shapes from rear to front.

[0053] This ensures that the cold air in the film cooling hole 2 smoothly enters the shroud cavity 4, flows smoothly along the shroud cavity 4, and finally smoothly exits through the opening 41. The cold air exiting through the opening 41 expands in a left-right direction, increasing the area covered by the film cooling crossflow, improving the lateral uniformity of the film cooling, and promoting contact between the cold air and the turbine blades, thereby enhancing the cooling effect of the turbine blades. Simultaneously, it reduces the cold air jet flow rate, increases the spacing between the kidney-shaped vortex pairs to reduce induced lift, and effectively suppresses the formation of kidney-shaped vortices. It also improves the utilization rate of cold air; compared to film cooling holes in related technologies, it reduces the amount of cold air used while achieving the same cooling effect.

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

[0055] like Figure 1 , Figure 3 , Figure 4 , Figure 6 and Figure 7 As shown, the film gas vent 2 includes a constant section 23 and an expansion section 24 connected sequentially from the inlet 22 to the outlet 21. The cross-sectional area of ​​the constant section 23 is constant along the direction of cold air flow in the film gas vent 2, while the cross-sectional area of ​​the expansion section 24 increases along the direction of cold air flow in the film gas vent 2. The expansion section 24 can be configured to increase the width of its cross-section along the direction of cold air flow in the film gas vent 2, or it can be configured to increase the length of its cross-section along the direction of cold air flow in the film gas vent 2. Preferably, both the width and length of its cross-section along the direction of cold air flow in the film gas vent 2 are increased.

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

[0057] The air film vents are designed with a constant section and an expansion section connected in sequence, so that the cold air is discharged in an expanded form, which increases the area of ​​the air film crossflow coverage area, improves the lateral uniformity of the air film, promotes 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 cold air jet flow, increase the spacing between the kidney vortex pairs to reduce the induced lift, effectively suppress the formation of kidney 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 an elliptical arc segment 231 and a circular arc segment 232 arranged opposite to each other, and the corresponding circular arc segments 232 are connected between the ends of the elliptical arc segments 231 arranged in the same direction.

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

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

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

[0062] like Figure 8 As shown, the length L1 of the constant segment 23 is the maximum dimension of the cross-section of the constant segment 23 in the left-right direction, and the width W1 of the constant segment 23 is the maximum dimension of the cross-section of the constant segment 23 in the front-back direction. L1 / W1≥3 makes the cross-section of the constant segment 23 strip-shaped, which in turn makes the cross-section of the film gas hole strip-shaped. This increases the area of ​​the cross-flow coverage of the film gas, improves the lateral uniformity of the film gas, promotes the contact between the cold air and the turbine blades, thereby improving the cooling effect of the turbine blades and improving the utilization rate of the cold air. Compared with the film gas hole in related technologies, the amount of cold air used can be reduced while achieving the same cooling effect.

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

[0064] like Figure 7As shown, the length L2 of the opening 41 of the shroud 4 is the maximum dimension of the opening 41 in the left-right direction, and the width W2 of the opening 41 of the shroud 4 is the maximum dimension of the opening 41 in the up-down direction. L2 / W2≥3 makes the opening 41 of the shroud 4 strip-shaped, which can increase the area of ​​the crossflow coverage 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 improving the utilization rate of cold air. Compared with the air film holes in related technologies, the amount of cold air used can be reduced while achieving the same cooling effect.

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

[0066] like Figure 4 and Figure 5 As shown, the inner wall of the deflector 3 includes a first inner section 31 and a second inner section 32 connected sequentially from back to front. The first inner section 31 connects the second inner section 32 and the wall of the film gas vent 2. The first inner section 31 extends from back to front and is located away from the outer wall of the turbine blade 1 (e.g., Figure 5 The second inner section 32 is inclined in the upward direction shown. It extends from back to front and is positioned close to the outer wall surface of the turbine blade 1 (as shown in the image). Figure 5 The downward direction shown is tilted.

[0067] The first and second inner sections work together to guide the flow of cold air. On the one hand, this ensures smooth flow of cold air. On the other hand, by compressing the path of the cold air flowing upward through the second inner section, it can further flow slightly downward, which promotes better flow of cold air against the outer wall of the turbine blades after impacting them. This enhances the impact cooling effect of the cold air near the opening and improves the film cooling effect.

[0068] In some embodiments, the cross-section of the first inner section 31 and the cross-section of the second inner section 32 are both arcs in the longitudinal section of the cavity 4.

[0069] like Figure 5 As shown, in the longitudinal section of the 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 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 projection of the inner wall surface of the cavity 4 and the outer wall surface on that longitudinal section.

[0071] like Figure 6 and Figure 7 As shown, the inner wall of the flow guide 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 connected between the inner middle section and the left end hole wall of the air film hole 2, and the inner right section is connected between the inner middle section and the right end hole wall of the air film hole 2. Since the cross-section of the first inner section 31 and the cross-section of the second inner section 32 are both curved in the longitudinal section of the shroud cavity 4, the parts of the first inner section 31 on the inner left section, inner middle section, and inner right section are all curved surfaces, and the parts of the second inner section 32 on the inner left section, inner middle section, and inner right section are all curved surfaces.

[0072] In some embodiments, the outer wall of the flow guide shroud 3 includes a first outer section 33 and a second outer section 34, which are sequentially arranged along the direction of medium flow within the shroud cavity 4. Both the first outer section 33 and the second outer section 34 extend along the direction of medium flow within the shroud cavity 4 and are inclined away from the outer wall of the turbine blade 1. Alternatively, the first outer section 33 extends along the direction of medium flow within the shroud cavity 4 and is inclined away from the outer wall of the turbine blade 1, while the second outer section 34 extends along the direction of medium flow within the shroud cavity 4 and is parallel to the extending direction of the outer wall of the turbine blade 1.

[0073] like Figure 5 As shown, the outer wall of the fairing 3 includes a first outer section 33 and a second outer section 34 connected sequentially from back to front. The first outer section 33 connects the second outer section 34 and the outer wall of the turbine blade 1. The first outer section 33 extends from back to front and along a direction away from the outer wall of the turbine blade 1 (e.g., Figure 5 The second outer segment 34 is inclined in the direction shown (upward). It extends from rear to front and is positioned away from the outer wall surface of the turbine blade 1 (e.g., in the direction shown). Figure 5 It is inclined in the upward direction shown, or it is set parallel to the extension direction of the outer wall surface of the turbine blade 1, in other words, it extends in a straight line in the front-back direction.

[0074] The first and second outer sections work together to guide the flow of mainstream gases such as fuel gas, reducing the mixing of mainstream gases with cold air. At the same time, the streamlined outer contour design can effectively reduce aerodynamic losses to the mainstream gases.

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

[0076] like Figure 5As shown, in the longitudinal section of the shroud 4, the first outer section 33 has an arc to reduce the aerodynamic loss of the first outer section 33, which is the windward surface, to the mainstream gas. The second outer section 34 has a straight line or an arc. Specifically, it can be a diagonal line or an arc extending from back to front and sloping upward, or it can be a straight line extending from back to front. Preferably, it is an arc extending from back to front and sloping upward, so as to have less aerodynamic loss.

[0077] like Figure 6 and Figure 7 As shown, the outer wall of the fairing 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 connected between the outer middle section and the outer wall of the turbine blade 1, and the outer right section is connected between the outer middle section and the outer wall of the turbine blade 1. Since 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 in the longitudinal section of the fairing cavity 4, the parts of the first outer section 33 on the outer left section, outer middle section, and outer right section are all curved surfaces, and the parts of the second outer section 34 on the outer left section and outer right section are curved surfaces, while the part on the outer middle section is a plane or curved surface.

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

[0079] like Figures 1-3 As shown, the connecting line between the outer wall of the shroud 4 and the outer wall 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-back direction, and the rear outer section is a straight line extending in the left-right direction. A first rounded corner section 5 is provided between the left outer section and the rear outer section for transition connection, and another first rounded corner section 5 is provided between the right outer section and the rear outer section for transition connection.

[0080] The connection line between the inner wall of the cavity 4 and the outer wall 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. The left inner section and the right inner section are both second rounded corner sections 6 directly connected to the rear inner section. Alternatively, the left inner section and the right inner section are straight lines extending in the front-back direction. A second rounded corner section 6 is provided as a transition connection between the left inner section and the rear inner section, and another second rounded corner section 6 is provided as a 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 rounded corner sections 6 directly connected to the rear inner section.

[0081] The radius of the first rounded segment 5 is smaller than the radius of the second rounded segment 6. This allows the cold air to expand laterally from the opening, promoting the lateral expansion of the cold air and increasing the area covered by the crossflow of the air film. At the same time, it can suppress the formation of kidney-shaped vortex pairs and further form anti-kidney vortex flow, thereby improving the air film cooling efficiency.

[0082] Embodiments of the present invention also propose a gas turbine.

[0083] The gas turbine of this invention includes turbine blades and a film cooling assembly suitable for turbine blades according to this invention.

[0084] The gas turbine of this invention has a film cooling assembly suitable for turbine blades installed on the turbine blades, which has a better film cooling effect, thereby reducing the amount of cooling gas used, reducing the maintenance and replacement frequency of the film cooling assembly suitable for turbine blades, and making it more environmentally adaptable.

[0085] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0086] Furthermore, the terms "first" and "second" are used only for distinction and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0087] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0088] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0089] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0090] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A film cooling assembly suitable for turbine blades, characterized in that, include: A film cooling hole (2) is provided on the turbine blade (1), and a flow guide (3) is provided on the outer wall surface of the turbine blade (1). A cavity (4) with an opening (41) is formed between the flow guide (3) and the outer wall surface of the turbine blade (1). The cavity (4) is connected to the outlet (21) of the film cooling hole (2). On the outer wall surface of the turbine blade (1), the projection of the inlet (22) of the film cooling hole (2), the outlet (21) of the film cooling hole (2), and the flow guide (3) are visible. The projections of the openings (41) of 3) are arranged in sequence. The air film holes (2) and the cover cavity (4) are both set as horizontally extending strips. The cross-sections of the air film holes and the cover cavity are strips, which can increase the area of ​​the air film crossflow coverage area, 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. At the same time, it can reduce the cold air jet flow rate, increase the kidney vortex pair spacing to reduce the induced lift, effectively suppress the formation of kidney vortices, and also improve the cold air utilization rate. The line connecting the outer wall of the shroud (4) and the outer wall of the turbine blade (1) has a first rounded corner segment (5), and the line connecting the inner wall of the shroud (4) and the outer wall of the turbine blade (1) has a second rounded corner segment (6). The radius of the first rounded corner segment (5) is smaller than the radius of the second rounded corner segment (6) so that the cold air is ejected laterally from the opening (41), promoting the lateral expansion of the cold air, increasing the area of ​​the crossflow coverage of the air film, and suppressing the formation of kidney-shaped vortex pairs. Furthermore, it can also form anti-kidney vortex flow, thereby improving the air film cooling efficiency. The inner wall of the flow guide (3) includes a first inner section (31) and a second inner section (32). The first inner section (31) and the second inner section (32) are arranged sequentially along the direction of medium flow in the cavity (4). The first inner section (31) extends along the direction of medium flow in the cavity (4) and is inclined along the direction away from the outer wall of the turbine blade (1). The second inner section (32) extends along the direction of medium flow in the cavity (4) and is inclined along the direction close to the outer wall of the turbine blade (1).

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

3. The film cooling assembly for turbine blades according to claim 1 or 2, characterized in that, The film gas vent (2) includes a constant section (23) and an expanding section (24). The constant section (23) forms the inlet (22) of the film gas vent (2) on the inner wall surface of the turbine blade (1). The expanding section (24) forms the outlet (21) of the film gas vent (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 film gas vent (2), and the cross-sectional area of ​​the expanding section (24) increases along the direction of medium flow in the film gas vent (2).

4. The film cooling assembly for turbine blades according to claim 3, characterized in that, The cross-sectional profile of the constant segment (23) includes an elliptical arc segment (231) and a circular arc segment (232) arranged opposite to each other, with the corresponding circular arc segment (232) connecting the ends of the elliptical arc segment (231) in the same direction.

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

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

7. The film cooling assembly for turbine blades according to claim 1, characterized in that, In the longitudinal section of the cavity (4), the first inner section (31) has an arc shape, and the second inner section (32) has an arc shape.

8. The film cooling assembly for turbine blades according to claim 1, characterized in that, The outer wall of the flow guide (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 arranged sequentially along the direction of medium flow in the cavity (4); Both the first outer section (33) and the second outer section (34) extend along the direction of medium flow within the shroud (4) and are inclined away from the outer wall surface of the turbine blade (1); or The first outer segment (33) extends along the direction of medium flow in the cavity (4) and is inclined along the direction away from the outer wall surface of the turbine blade (1). The second outer segment (34) extends along the direction of medium flow in the cavity (4) and is parallel to the extension direction of 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 cavity (4), the first outer section (33) has an arc, and the second outer section (34) has a straight line or an arc.

10. A gas turbine, characterized in that, include: Turbine blade (1) and film cooling assembly for turbine blades according to any one of claims 1-9.

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