Turbine guide vane and gas turbine

Abstract

The invention provides a turbine guide blade. The turbine guide blade comprises a blade body and a heat shield. The blade body comprises a front edge directly facing gas incoming flow, a tail edge opposite to the front edge and a bent body portion located between the front edge and the tail edge. The heat shield covers the front edge and serves as a windward side making contact with fuel gas firstly, a cold air cavity penetrating through the heat shield in the longitudinal direction perpendicular to the flowing direction of the fuel gas is formed in the heat shield, and a plurality of heat dissipation channels are formed between the cold air cavity and the pressure face and the suction face of the body part so as to cool the front edge of the blade body.

Description

TECHNICAL FIELD

[0001] At least one embodiment of the present disclosure relates to the field of gas turbine blade cooling technology, and particularly relates to a turbine guide vane and a gas turbine. BACKGROUND

[0002] The turbine guide vane continuously bears the impact of high-temperature gas. In order to pursue higher thermal power conversion efficiency, the turbine inlet gas temperature of the current advanced gas turbine has reached above 1600 DEG C, and the thermal environment of the blade is more severe. In order to enable the blade to work safely for a long time, the prior art mainly cools the blade by spraying cooling gas to the surface of the blade or introducing cooling air into the internal passage of the blade, etc.

[0003] However, due to the non-uniformity of the gas in the flow process, the cooling effect of the leading edge of the blade first contacted with the gas does not match the actual demand, and the amount of cooling gas needs to be further increased to ensure the safe operation of the blade, thereby reducing the thermal efficiency of the gas turbine cycle and conflicting with the design goal of high-efficiency operation. SUMMARY

[0004] To solve the above and other aspects of at least one technical problem in the prior art, embodiments of the present disclosure provide a turbine guide vane and a gas turbine, which can effectively cool the leading edge of the blade and reduce the amount of cooling gas.

[0005] Embodiments of the present disclosure provide a turbine guide vane, which comprises a blade body and a thermal shield. The blade body comprises a leading edge facing the gas flow, a trailing edge opposite to the leading edge, and a curved body portion between the leading edge and the trailing edge. The thermal shield covers the leading edge and serves as the windward surface first contacted with the gas. The thermal shield is provided with a cooling gas cavity penetrating through the thermal shield in a longitudinal direction perpendicular to the flow direction of the gas, and a plurality of heat dissipation channels are formed between the cooling gas cavity and the pressure surface and the suction surface of the body portion to cool the leading edge of the blade body.

[0006] According to some embodiments of the present disclosure, the leading edge comprises an arc-shaped protruding portion, a plurality of convex ribs, and two transition portions. The arc-shaped protruding portion extends in the longitudinal direction. The plurality of convex ribs extend perpendicularly to the longitudinal direction and are distributed at intervals. The two transition portions are respectively located between the protruding portion and the pressure surface and the suction surface. The inner side of the thermal shield has a substantially U-shaped cross section, and comprises two side walls covering the protruding portion and a bottom wall connected between the side walls. The bottom wall is provided with a plurality of heat dissipation holes respectively communicating between the cooling gas cavity and the space between two adjacent convex ribs. The heat dissipation holes and the space defined by the convex ribs, the transition portions and the end portion of the thermal shield form the heat dissipation channels.

[0007] According to some embodiments of the present disclosure, the end on the protrusion forms a flat section extending in the longitudinal direction, and the plurality of protruding ribs form two sides of the flat section, so that the gas flowing out of the heat dissipation hole mixes in the space between the flat section and the bottom wall of the heat shield.

[0008] According to some embodiments of the present disclosure, a cross section of the cold air cavity perpendicular to the longitudinal direction is arc-shaped, and has two arc-shaped sections concave to the heat shield as a whole, and the curvature of the arc-shaped sections also matches the curvature of the inner side wall of the heat shield and the curvature of the protruding ribs.

[0009] According to some embodiments of the present disclosure, the body portion is provided with a first blind hole extending from the outer side of the body portion in the longitudinal direction. The body portion forms a plurality of first air outlet holes extending from the first blind hole to the pressure surface and the suction surface at a position close to the leading edge, and the cold air flowing into the first blind hole is discharged from the pressure surface and the suction surface through the first air outlet holes.

[0010] According to some embodiments of the present disclosure, the turbine guide vane further comprises a front air duct, an outer mounting bracket, a first cover plate and a second cover plate. The front air duct is inserted into the first blind hole, and a plurality of first through holes are provided on the side wall of the front air duct to guide the received cold air into the first blind hole. The outer mounting bracket is mounted on the outer side of the body portion. The first cover plate is adapted to mount the end of the front air duct extending out of the outer mounting bracket on the outer mounting bracket, and cover the gap between the heat shield on the inner side and the leading edge, and the cold air cavity is in communication with the outside through the first cover plate. The second cover plate is adapted to cover the gap between the heat shield on the inner side and the leading edge.

[0011] According to some embodiments of the present disclosure, the body portion is further provided with a second blind hole between the first blind hole and the trailing edge, and the second blind hole extends from the inner side of the body portion in the longitudinal direction. The body portion forms a plurality of second air outlet holes extending from the second blind hole to the pressure surface and the suction surface at a position close to the trailing edge, and a part of the cold air flowing into the second blind hole is discharged from the pressure surface and the suction surface through the second air outlet holes.

[0012] According to some embodiments of the present disclosure, the trailing edge is formed with third air outlet holes extending from the end of the second blind hole to the trailing edge, and another part of the cold air flowing into the second blind hole is discharged from the end of the trailing edge through the third air outlet holes.

[0013] According to some embodiments of the present disclosure, the turbine guide vane further comprises a rear air duct, an inner mounting bracket and a third cover plate. The rear air duct is inserted into the second blind hole, and a plurality of second through holes are provided on the side wall of the rear air duct to guide the received cold air into the second blind hole. The inner mounting bracket is mounted on the inner side of the body portion. The third cover plate is adapted to mount the end of the rear air duct extending out of the inner mounting bracket on the inner mounting bracket, and cover the second blind hole.

[0014] In another aspect, the embodiments of the present disclosure provide a gas turbine comprising the turbine guide vane according to any of the above embodiments.

[0015] According to the turbine guide vane provided by the present disclosure, by covering the heat shield as the windward surface first contacted with the gas at the leading edge of the blade body, the impact of high-temperature gas directly borne by the blade body can be reduced, and meanwhile, by using the cold gas cavity extending longitudinally along the vertical direction of the gas flow in the heat shield, the leading edge region of the overall turbine guide vane where the concentrated thermal load exists can be cooled in response to the non-uniformity of the gas flow. This design reduces the dependence on the amount of cooling gas while effectively improving the heat damage resistance of the leading edge region, alleviates the defects of blade damage due to insufficient cooling and reduced efficiency due to excessive cooling, and realizes the coordination of safe operation of the blade and high-efficiency operation of the gas turbine. The gas turbine using the turbine guide vane can reduce the consumption of cold gas and the adverse effects on the thermal efficiency of the gas turbine cycle by optimizing the cooling and protection structure of the blade while maintaining a high level of turbine inlet gas temperature to pursue high thermal power conversion efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0016] The above and other objects, features and advantages of the present disclosure will become more apparent from the following description of embodiments of the present disclosure taken in conjunction with the accompanying drawings, in which:

[0017] Figure 1 A perspective view schematically showing a turbine guide vane according to an embodiment of the present disclosure is shown;

[0018] Figure 2 A perspective view schematically showing a heat shield of a turbine guide vane according to an embodiment of the present disclosure is shown;

[0019] Figure 3 A flow direction view schematically showing gas and cold gas of a gas turbine according to an embodiment of the present disclosure is shown;

[0020] Figure 4 A cross-sectional view schematically showing a turbine guide vane according to an embodiment of the present disclosure along the flow direction of the gas is shown, and the cold gas flow direction is shown;

[0021] Figure 5 A longitudinal section view schematically showing a turbine guide vane according to an embodiment of the present disclosure is shown;

[0022] Figure 6 A partial enlarged view of part A of FIG. 8 schematically showing a turbine guide vane according to an embodiment of the present disclosure is shown; Figure 4

[0023] Figure 7 A perspective view schematically showing a blade body of a turbine guide vane according to an embodiment of the present disclosure is shown. ​

[0024] In the drawings, the following reference signs have the following meanings:

[0025] 1-blade; 11-leading edge; 111-protrusion; 112-flat portion; 113-rib; 114-transition portion; 12-body portion; 121-pressure surface; 122-suction surface; 123-first blind hole; 124-first air outlet hole; 125-second blind hole; 126-second air outlet hole; 13-trailing edge; 131-third air outlet hole; 2-thermal shield; 21-side wall; 22-radiating hole; 23-cooling air cavity; 3-front air duct; 31-first through hole; 4-outer mounting bracket; 5-first cover plate; 6-second cover plate; 7-rear air duct; 71-second through hole; 8-inner mounting bracket; 9-third cover plate; 10-elastic gasket. DETAILED DESCRIPTION

[0026] In order to make the objectives, technical solutions and advantages of the present disclosure clearer, further detailed description will be made to the present disclosure in combination with specific embodiments and with reference to the drawings.

[0027] The terms used herein are merely used to describe specific embodiments, and are not intended to limit the present disclosure. The terms "include", "comprise" and the like used herein indicate the presence of the features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.

[0028] All the terms used herein, including technical and scientific terms, have the meanings generally understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted to have meanings consistent with the context of the present specification, and should not be interpreted in an idealized or overly formal manner.

[0029] In the case of using expressions similar to "at least one of A, B, and C, etc.", it should be generally interpreted that the meaning of the expression is at least one of the items listed before the conjunction, unless otherwise clearly defined. For example, the expression "a system having at least one of A, B, and C" should be interpreted to include a system having at least one of A, a system having at least one of B, a system having at least one of C, a system having at least one of A and B, a system having at least one of A and C, a system having at least one of B and C, and / or a system having at least one of A, B, and C, etc. In the case of using expressions similar to "at least one of A, B, or C, etc.", it should be generally interpreted that the meaning of the expression is at least one of the items listed before the conjunction, unless otherwise clearly defined. For example, the expression "a system having at least one of A, B, or C" should be interpreted to include a system having at least one of A, a system having at least one of B, a system having at least one of C, a system having at least one of A and B, a system having at least one of A and C, a system having at least one of B and C, and / or a system having at least one of A, B, and C, etc.

[0030] It should be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only the directions of the drawings and are not intended to limit the protection scope of the present disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. When it may cause confusion to the understanding of the present disclosure, the conventional structures or configurations will be omitted.

[0031] Figure 1 A perspective view of a turbine guide vane is schematically shown. Figure 2 A perspective view of a hot shield of a turbine guide vane is schematically shown.

[0032] As Figures 1-2 shown, the embodiments of the present disclosure provide a turbine guide vane used as a static guide component of a gas turbine, comprising a blade body 1 and a hot shield 2. The blade body 1 comprises a leading edge 11 facing the gas flow, a trailing edge 13 opposite to the leading edge 11, and a curved body portion 12 between the leading edge 11 and the trailing edge 13. The hot shield 2 covers the leading edge 11 and serves as the windward surface first contacted by the gas, and the hot shield 2 is provided with a cold gas cavity 23 penetrating through the hot shield 2 in a longitudinal direction perpendicular to the flow direction of the gas, and a plurality of heat dissipation channels are formed between the cold gas cavity 23 and the pressure surface 121 and the suction surface 122 of the body portion 12 to cool the leading edge 11 of the blade body 1.

[0033] In an illustrative embodiment, the blade body 1 is integrally formed by the leading edge 11, the body portion 12 and the trailing edge 13 using a high-temperature alloy such as a nickel-based alloy. Meanwhile, in view of the problem that the leading edge 11 is directly subjected to the high-temperature gas flow, the hot shield 2 is made of a ceramic matrix composite material (CMC), such as a silicon carbide / silicon carbide fiber reinforced ceramic matrix composite material (SiC / SiC CMC), which has a silicon carbide ceramic matrix and a silicon carbide ceramic fiber reinforcement, and has both high-temperature strength and toughness after being combined.

[0034] Specifically, the CMC blade has mechanical and mechanical properties such as high-temperature resistance, wear resistance, and high hardness, and can directly work in a high-temperature gas environment. However, due to the limitations of the toughness, processing performance and assembly of ceramics, the CMC blade is difficult to obtain batch engineering applications, and the mechanical processing technology will destroy the fiber organization of the CMC and greatly degrade the mechanical properties of the CMC blade. Therefore, compared with the defect that the blade made of CMC cannot be constructed to be more complex, thin-walled or high-precision in size, the hot shield 2 made of CMC only covers the leading edge 11 and forms a complete blade structure with the metal blade body 1, and the structure of the hot shield 2 is simple, thereby avoiding the disadvantage of CMC processing complex structure.

[0035] Further, the blade body 1 and the hot shroud 2 are processed respectively, and then combined and packaged into a turbine guide vane. Among them, the CMC hot shroud 2 is wrapped on the leading edge 11, which is used as the windward surface first contacted with the gas, that is, the leading edge 11 region on the whole of the turbine guide vane. In this way, the high-temperature resistance of CMC is utilized to resist the gas scouring, and the high-temperature alloy of the blade body 1 ensures the processability and bearing performance of the overall structure, realizing the collaborative design of “hot end protection” and “structural reliability”.

[0036] Figure 3 The flow direction of the gas and the cold gas of the gas turbine according to the embodiment of the present disclosure is schematically shown.

[0037] In an illustrative embodiment, as shown in Figure 3 , the shaded area is a turbine guide vane, which is a stationary flow guide component of the turbine of the gas turbine. The gas turbine further includes a casing, an inner ring, a compressor, a combustion chamber, a moving blade group, and a rotating shaft (these components are not explicitly shown in Figure 3 ). The casing serves as the shell of the gas turbine, and presents a ring structure along the axial direction (length direction) of the gas turbine; the inner ring is arranged close to the central axis of the gas turbine, and presents a ring structure along the axial direction of the gas turbine, which is located inside the casing and coaxial with the casing; the compressor is suitable for compressing air; the combustion chamber can mix and ignite fuel with high-pressure air to generate gas; the moving blade group and the rotating shaft are both rotating components of the turbine of the gas turbine, and the rotating shaft is located on the central axis of the gas turbine, and a plurality of moving blades are distributed circumferentially around the rotating shaft to form the moving blade group.

[0038] Specifically, in the gas turbine, the compressor first compresses the external air, and the high-pressure air formed is partially introduced into the combustion chamber to generate high-temperature and high-pressure gas, and the other part bypasses the combustion chamber to become cold gas. A plurality of turbine guide vanes are arranged circumferentially along the ring-shaped fitting surface of the inner ring and the casing, guide the gas to the subsequent moving blade group, and the moving blade group absorbs the energy of the gas to drive the rotating shaft to rotate.

[0039] Further, in the gas turbine, the casing is the peripheral fixed component of the turbine guide vane (the upper connecting component of the shaded area in Figure 3 ), which constitutes the outer boundary of the gas passage, and the inner ring is the inner fixed component of the turbine guide vane (the lower connecting component of the shaded area in Figure 3 ), which constitutes the inner boundary of the gas passage, and the turbine guide vane is fixed between the inner ring and the casing through the inner and outer sides, and the three together define the flow space of the gas and enclose the gas passage. The gas discharged from the combustion chamber (the left arrow in Figure 3 ) flows in this passage and first impacts the windward surface of the turbine guide vane (the upper connecting component of the shaded area in Figure 3The gas arrow in the middle points directly to the heat shield 2 of the turbine guide vane, that is, the turbine guide vane is at the front end of the gas flow path. After being "shaped" by the aerodynamic surface of the turbine guide vane, the gas flows along the trailing edge 13 of the turbine guide vane to the subsequent moving blade group, realizing efficient transfer of gas energy.

[0040] Furthermore, the cold air discharged from the compressor is divided into two paths ( Figure 3 Cooling air (as indicated by the upper and lower arrows in the figure) is passed into the turbine guide vanes to reduce the heat load and ensure the structural safety of the turbine guide vanes in a high-temperature gas environment. Cooling air can be passed from the cooling air cavity 23 into the interior of the heat shield 2, thereby cooling the leading edge 11 area covered by the heat shield 2.

[0041] Figure 4 A schematic cross-sectional view of a turbine guide vane along the gas flow direction according to an embodiment of the present disclosure is shown schematically, and the cold air flow direction is shown in the figure. Figure 5 A longitudinal cross-sectional view of a turbine guide vane according to an embodiment of the present disclosure is schematically shown. Figure 6 Schematically shows an embodiment of the present disclosure Figure 4 A partial enlarged view of part A.

[0042] like Figures 4-6 As shown, the main body 12 includes a pressure surface 121 with a convex arc structure, a suction surface 122 with a concave arc structure opposite to the pressure surface 121, and an inner side surface and an outer side surface perpendicular to the pressure surface 121 and the suction surface 122. The pressure surface 121 and the suction surface 122 together constitute the aerodynamic profile of the main body 12. When the gas flows through the pressure surface 121, the convex arc surface reduces the airflow velocity and increases the pressure, while when it flows through the suction surface 122, the concave arc surface increases the airflow velocity and reduces the pressure. Both the inner side surface and the outer side surface serve as mounting interfaces for the main body 12. The inner side surface is opposite and parallel to the annular mounting surface of the inner ring, while the outer side surface is opposite and parallel to the inner wall surface of the casing.

[0043] According to the above-described arrangement, as the gas flows from the heat shield 2 to the pressure surface 121 and suction surface 122, respectively, it continuously rotates and accelerates within the flow path between adjacent turbine guide vanes, providing uniform impact kinetic energy to the blades. By enclosing the heat shield 2 at the leading edge 11 of the blade airfoil 1, which serves as the windward surface that first contacts the gas, the direct impact of the high-temperature gas on the blade airfoil is reduced. Simultaneously, a cooling air cavity 23 extending longitudinally within the heat shield 2, perpendicular to the gas flow direction, responds to the unevenness of the gas flow and cools the windward surface (i.e., the leading edge 11 region of the turbine guide vane as a whole) where concentrated heat loads are present. This design reduces reliance on cooling air consumption while effectively improving the leading edge 11 region's resistance to thermal damage. This mitigates the risks of blade damage caused by insufficient cooling and reduced efficiency due to excessive cooling, thereby achieving synergy between safe blade operation and efficient gas turbine operation. The gas turbine adopts this turbine guide vane, which can reduce the cooling air consumption and the adverse effect on the thermal efficiency of the gas turbine cycle through the optimized cooling and protection structure of the blades while maintaining the turbine inlet gas temperature at a high level to pursue high heat-to-work conversion efficiency.

[0044] Figure 7 A perspective view of a blade body of a turbine guide vane according to an embodiment of the present disclosure is schematically shown.

[0045] like Figure 6 and Figure 7 As shown, the leading edge 11 includes an arc-shaped raised portion 111, a plurality of ribs 113 and two transition portions 114. The arc-shaped raised portion 111 is longitudinally ( Figure 6 The heat shield 2 extends in a direction perpendicular to the paper. Multiple ribs 113 extend perpendicular to the longitudinal direction and are spaced apart in the longitudinal direction. Two transition portions 114 are located on either side of the raised portion 111, between the pressure surface 121 and the suction surface 122. The inner cross-section of the heat shield 2 has a roughly U-shaped shape and includes two sidewalls 21 covering the raised portions 111, and a bottom wall connecting the sidewalls 21. The bottom wall is provided with multiple heat dissipation holes 22 that connect the cooling cavity 23 with the space between two adjacent ribs. The heat dissipation holes 22, the space between the ribs 113, the outer surface of the raised portion 111, and the inner surface of the sidewalls 21, and the space defined by the transition portions 114 and the end of the heat shield 2 form a heat dissipation channel. This allows gas to enter the cooling cavity 23 from both sides of the heat shield 2, then flow out of the pressure surface 121 and the suction surface 122 through the heat dissipation channel, effectively improving the overall resistance of the leading edge 11 area of ​​the turbine guide vane to thermal damage.

[0046] In an exemplary embodiment, the end of the thermal shield 2 matches the protruding part 111, the plurality of convex ribs 113 and the two transition parts 114. Specifically, the side wall 21 of the thermal shield 2 is symmetrically distributed on both sides of the heat dissipation hole 22, the surface of the side wall 21 is a longitudinally extending arc-shaped curved surface, the surface of the protruding part 111 is also a longitudinally extending arc-shaped curved surface, and the plurality of convex ribs 113 each has two identical arc-shaped curved surfaces, the arc-shaped curved surface of the convex rib 113 matches the arc-shaped curved surface of the protruding part 111, and at the same time, the arc-shaped curved surface of the side wall 21 of the thermal shield 2 matches the arc-shaped curved surface of the protruding part 111 and the arc-shaped curved surface of the convex rib 113, when the arc-shaped curved surface of the side wall 21 is arranged opposite to the arc-shaped curved surface of the protruding part 111, one arc-shaped curved surface of the plurality of convex ribs 113 is combined with the arc-shaped curved surface of the protruding part 111, and the other arc-shaped curved surface of the plurality of convex ribs 113 faces the arc-shaped curved surface of the side wall 21.

[0047] Further, the transition part 114 is a longitudinally extending flat plate, which is symmetrically distributed on both sides of the protruding part 111, and the longitudinal plane of the transition part 114 forms an angle of 90 to 180 degrees with the pressure surface 121 and the suction surface 122. In addition, the thermal shield 2 also has two longitudinal planes which are symmetrically distributed on both sides of the two side walls 21, the angle between the longitudinal plane and the bottom wall is in the range of 0 to 90 degrees, and when the thermal shield 2 is combined with the blade 1, the protruding part 111 is embedded in the space surrounded by the two side walls 21 of the thermal shield 2, and the two longitudinal planes of the end of the two side walls 21 of the thermal shield 2 are opposite and parallel to the two longitudinal planes of the transition part 114.

[0048] Further, the heat dissipation hole 22 can be a cylindrical hole or a special-shaped hole, which is made by electro-processing or laser drilling.

[0049] According to the above setting mode, in the area of the leading edge 11 of the turbine guide vane, on the one hand, by setting the matching protruding part 111 and side wall 21, the positioning speed during the combination of the blade 1 and the thermal shield 2 is improved, and after the assembly is completed, the connection stiffness of the thermal shield 2 and the blade 1 is enhanced by the mechanical support of the plurality of convex ribs 113 and the three-dimensional constraint of the U-shaped inner side of the thermal shield 2, which effectively reduces the risk of thermal shield 2 deviation and falling off; on the other hand, the cold air can flow in the gap formed after the combination of the thermal shield 2 and the blade 1, which helps to cool the leading edge 11 area and ensures the stable connection of the thermal shield 2 to the leading edge 11 structure, thereby improving the reliability and stability of the turbine guide vane in use.

[0050] According to some embodiments of the present disclosure, the end of the protrusion 111 forms a flat section 112 extending in the longitudinal direction, and a plurality of convex ribs 113 are formed on both sides of the flat section 112, so that the gas flowing out of the heat dissipation hole 22 mixes in the space between the flat section 112 and the bottom wall of the heat shield 2. The cross section of the cold air cavity 23 perpendicular to the longitudinal direction is arc-shaped, and has two arc-shaped sections concave to the heat shield 2 as a whole, and the curvature of the arc-shaped sections matches the curvature of the side wall 21 of the heat shield 2 and the curvature of the convex ribs 113.

[0051] In an illustrative embodiment, the plurality of convex ribs 113 are symmetrically distributed on both sides of the flat section 112, the cold air cavity 23 extends through the heat shield 2 in the longitudinal direction, the two semi-encircling arc-shaped surfaces of the cold air cavity 23 are oppositely arranged and smoothly transitioned by two arc-shaped surfaces each extending in the longitudinal direction and concave to each other. Specifically, the cross-sectional area of the cold air cavity 23 accounts for 40%-70% of the cross-sectional area of the heat shield 2, and is distributed close to the leading edge 11. The arc length of the two arc edges of the cross section of the cold air cavity 23 concave to each other is relatively long, the length of the two arc edges can be substantially the same as the covering length of the cross section of the heat shield 2 to the cross section of the leading edge 11, and the distance between the two arc edges is in the form of large in the center and small at both ends, while the arc length of the two arc edges of the cross section of the cold air cavity 23 concave to each other is relatively short.

[0052] Further, the heat dissipation channel can be specifically divided into three sections: since the cold air can flow from the internal space of the cold air cavity 23 along the heat dissipation hole 22 to the space between the two convex ribs 113 adjacent in the longitudinal direction, the space defined by the plurality of heat dissipation holes 22 during this process forms the first section of the heat dissipation channel; since when the heat shield 2 is combined with the blade body 1, there is still a gap between the space between the two convex ribs 113 adjacent in the longitudinal direction and the surface of the side wall 21, which can be used for the cold air flowing out of the first section of the heat dissipation channel to continue to flow, the space defined by the convex ribs 113 and the end of the heat shield 2 during this process forms the second section of the heat dissipation channel; since when the heat shield 2 is combined with the blade body 1, there is still a gap between the heat shield 2 and the transition section 114, which can be used for the cold air flowing out of the second section of the heat dissipation channel to continue to flow between the heat shield 2 and the transition section 114, and further to the pressure surface 121 and the suction surface 122, the space defined by the transition section 114 and the end of the heat shield 2 during this process forms the third section of the heat dissipation channel.

[0053] Further, when the cold air enters the cold air cavity 23, it continues to be discharged to the space between the heat shield 2 and the leading edge 11 through the first row of heat dissipation air outlet holes 22, and forms a cold air film on the surface of the pressure surface 121 and the suction surface 122.

[0054] In an illustrative embodiment, the edge of the cross section of the heat shield 2 (the outlet position of the heat dissipation channel) Figure 6 is smoothly transitioned with a circular arc edge.

[0055] According to the above setting mode, when the cold air flows along the cold air cavity 23 and along the heat dissipation channel, the thermal stress of the leading edge 11 area caused by the gas is effectively reduced, the leading edge structure of the turbine guide vane is cooled and protected, and the turbine guide vane helps to stably conduct the gas. Among them, the reserved flat part 112 not only brings convenience to the assembly of the heat shield 2 and speeds up the alignment, but also increases the space of the heat dissipation channel formed after the convex rib 113 is combined with the side wall 21, thereby expanding the cold air capacity and improving the cooling efficiency. Moreover, the cold air film formed by the heat shield 2 isolates the high-temperature gas, effectively improves the cooling effect of the leading edge 11 area, thereby improving the utilization efficiency of the cold air. In addition, the circular arc edge of the heat shield 2 promotes the diffusion of the cold air flowing out of the heat dissipation channel, thereby increasing the cooling area, and can effectively avoid the situation that the gas film cooling is broken at the sharp corner due to the failure of the airflow to adhere to the abrupt surface, which is beneficial to make the gas film cover more complete and enhance the cooling protection effect.

[0056] According to some embodiments of the present disclosure, the body part 12 is provided with a first blind hole 123 extending in the longitudinal direction from the outer side of the body part 12. The body part 12 is formed with a plurality of first exhaust holes 124 extending from the first blind hole 123 to the pressure surface 121 and the suction surface 122 to form a first exhaust channel near the position of the leading edge 11, and the cold air flowing into the first blind hole 123 is discharged from the pressure surface 121 and the suction surface 122 through the first exhaust hole 124.

[0057] In an illustrative embodiment, the first blind hole 123 serves as a channel for the cold air near the casing to enter the body part 12. The first exhaust hole 124 can be a cylindrical hole or a special-shaped hole, which is made by electro-processing or laser drilling.

[0058] Further, when the cold air enters the first blind hole 123 from the outer side of the body part 12, it continues to be discharged from the body part 12 through the first exhaust hole 124, and forms a cold air film on the surface of the pressure surface 121 and the suction surface 122.

[0059] According to the above setting mode, the first blind hole 123 directly introduces the cold air near the casing into the body part 12 from the outer side, wherein the closed end structure of the first blind hole 123 allows the cold air to reside inside the body part 12, reducing the loss of cold air. By flowing along the first exhaust channel, the thermal stress of the nearby body part 12 caused by the gas is effectively reduced, the local structure of the turbine guide vane is cooled and protected, and the turbine guide vane helps to stably conduct the gas. Among them, the cold air film formed by the heat shield 2 isolates the high-temperature gas, effectively improves the cooling effect of the body part 12, thereby improving the utilization efficiency of the cold air.

[0060] According to some embodiments of the present disclosure, the turbine guide vane further comprises a front air duct 3, an outer mounting bracket 4, a first cover plate 5 and a second cover plate 6. The front air duct 3 is inserted into the first blind hole 123, and a plurality of first through holes 31 are arranged on the sidewall 21 of the front air duct 3 to guide the received cold air into the first blind hole 123. The outer mounting bracket 4 is mounted on the outer side of the body portion 12. The first cover plate 5 is adapted to mount the end of the front air duct 3 extending out of the outer mounting bracket 4 on the outer mounting bracket 4, and cover the gap between the hot shield 2 on the outer side and the leading edge 11, and the cold air cavity 23 is in communication with the outside through the first cover plate 5. The second cover plate 6 is adapted to cover the gap between the hot shield 2 on the inner side and the leading edge 11.

[0061] In an exemplary embodiment, when the turbine guide vane is fixed to the casing through the outer mounting bracket 4, a gap may exist at the mounting interface. To prevent the cold air from leaking from the gap, the front air duct 3 is provided as a flow guide structure. The front air duct 3 is a hollow cylindrical structure to guide the received cold air into the first blind hole 123, and the front air duct 3 and the first blind hole 123 form an annular gap extending in the longitudinal direction.

[0062] In an exemplary embodiment, the outer mounting bracket 4 can adopt an integrated frame, including but not limited to a dovetail fixed to the outer side of the body portion 12 or the upper side or the upper edge of the body portion 12 in the circumferential direction by bolts. Figure 1 and Figure 4 Further, the outer mounting bracket 4 can be integrated with a hook-shaped clamping structure to engage with the annular clamping groove of the inner wall of the casing.

[0063] Further, the first cover plate 5 includes but is not limited to a disc-shaped plate. The first cover plate 5 further has a hole for the front air duct 3 to pass through, and is fastened to the outer side of the body portion 12 by welding or arranging circumferential bolts, and simultaneously covers the gap between the first blind hole 123 and the front air duct 3, and the gap between the hot shield 2 on the outer side and the leading edge 11. An elastic gasket 10 is arranged between the first cover plate 5 and the hot shield 2 to allow the hot shield 2 to move in the longitudinal direction. The second cover plate 6 includes but is not limited to an arc-shaped thin plate. The second cover plate 6 can be fastened to the inner side of the body portion 12 by laser welding, and simultaneously cover the gap between the hot shield 2 on the inner side and the leading edge 11. The first cover plate 5 and the second cover plate 6 are respectively provided with a slot hole for the side cold air to enter the cold air cavity 23 of the hot shield 2.

[0064] According to the above setting mode, by opening a plurality of first through holes 31 on the side wall 21 of the front air guide cylinder 3, direct pouring of cold air into the front air guide cylinder 3 is prevented, and a one-sided high-speed flow is formed due to the direct impact effect, helping the high-pressure cold air to diffuse along the circumference of the front air guide cylinder 3 to the annular chamber of the first blind hole 123, reducing the local retention of cold air. In addition, by adding an elastic gasket 10 to help the thermal shield 2 move, the problem that the CMC thermal shield 2 cannot meet the fitting requirements due to the smaller linear expansion coefficient than metal materials under thermal conditions is effectively solved.

[0065] According to some embodiments of the present disclosure, the body part 12 is further provided with a second blind hole 125 located between the first blind hole 123 and the trailing edge 13, the second blind hole 125 extending from the inner side of the body part 12 in the longitudinal direction. The body part 12 is formed with a plurality of second exhaust holes 126 forming a second exhaust passage extending from the second blind hole 125 to the pressure surface 121 and the suction surface 122 near the trailing edge 13, and a part of the cold air flowing into the second blind hole 125 is discharged from the pressure surface 121 and the suction surface 122 through the second exhaust holes 126.

[0066] According to some embodiments of the present disclosure, the trailing edge 13 is formed with a third exhaust hole 131 forming a third exhaust passage extending from the second blind hole 125 to the end of the trailing edge 13, and another part of the cold air flowing into the second blind hole 125 is discharged from the end of the trailing edge 13 through the third exhaust hole 131.

[0067] In an illustrative embodiment, the second blind hole 125 serves as a passage for cold air entering the body part 12 near the inner ring. The second exhaust hole 126 can be a cylindrical hole or a special-shaped hole, which is made by electrochemical machining or laser drilling.

[0068] Further, when the cold air enters the second blind hole 125 from the inner side, part of the cold air is discharged to the surface of the pressure surface 121 and the suction surface 122 of the body part 12 through the second exhaust hole 126, forming a cold air film.

[0069] In an illustrative embodiment, the trailing edge 13 is relatively slender in structure compared to the body part 12.

[0070] According to the above setting mode, the second blind hole 125 directly introduces the cold air near the inner ring from the inner side to the body part 12, wherein the closed end structure of the second blind hole 125 enables the cold air to stay inside the body part 12, reducing the loss of cold air, and when the gas flows to the pressure surface 121 and the suction surface 122 from the hot shroud 2 respectively, the cold air flows along the second blind hole 125 and part of the cold air flows along the second exhaust passage, effectively reducing the thermal stress of the body part 12 caused by the gas, cooling and protecting the local structure of the turbine guide vane, and helping the turbine guide vane to stably conduct the gas. Among them, the high-temperature gas is isolated by the cold air film, which further improves the cooling effect of the body part 12, thereby improving the utilization efficiency of the cold air. In addition, another part of the cold air flowing into the second blind hole 125 flows along the third exhaust passage, effectively reducing the thermal stress of the trailing edge 13 region caused by the gas, cooling and protecting the trailing edge 13 structure of the turbine guide vane, and ensuring that the gas smoothly turns to the subsequent blade group along the trailing edge 13.

[0071] According to some embodiments of the present disclosure, the turbine guide vane further comprises a rear air duct 7, an inner mounting frame 8 and a third cover plate 9. The rear air duct 7 is inserted into the second blind hole 125, and a plurality of second through holes 71 are arranged on the side wall 21 of the rear air duct 7 to guide the received cold air into the second blind hole 125. The inner mounting frame 8 is mounted on the inner side of the body part 12 (i.e. the lower side or lower edge in the Figure 1 and Figure 4 The third cover plate 9 is suitable for mounting the end of the rear air duct 7 extending out of the inner mounting frame 8 on the inner mounting frame 8 and covering the second blind hole 125.

[0072] In an illustrative embodiment, when the turbine guide vane is fixed to the inner ring through the inner mounting frame 8, a gap may exist at the mounting interface. In order to prevent the cold air from leaking from the gap, the rear air duct 7 is arranged as a flow guide structure. The rear air duct 7 is a hollow cylindrical structure to guide the received cold air into the second blind hole 125, and the rear air duct 7 and the second blind hole 125 form an annular gap extending in the longitudinal direction.

[0073] In an illustrative embodiment, the inner mounting frame 8 can be an integrated frame, including but not limited to being fixed to the inner side of the body part 12 by dovetail and circumferential bolts. And the inner mounting frame 8 is fastened to the mounting surface of the inner ring by bolts.

[0074] Further, the third cover plate 9 includes but is not limited to a disc-shaped plate. The third cover plate 9 has a hole for the rear air duct 7 to pass through, and is fastened to the inner side of the body part 12 by welding or arranging circumferential bolts, and simultaneously covers the gap between the second blind hole 125 and the rear air duct 7.

[0075] According to the above-mentioned setting method, multiple second through holes 71 are opened on the side wall 21 of the rear air duct 7 to prevent the cold air from directly entering the rear air duct 7 and forming a unilateral high-speed flow due to the straight impact effect, thereby helping the high-pressure cold air to diffuse along the circumference of the rear air duct 7 to the annular chamber of the second blind hole 125, thereby reducing the local retention of cold air.

[0076] Another aspect of the embodiments of the present disclosure provides a gas turbine, comprising the turbine guide vanes described in any of the above embodiments, used as a stationary flow guide component of the gas turbine.

[0077] In an exemplary embodiment, the gas turbine further comprises a casing, an inner ring, a compressor, a combustion chamber, a blade assembly and a rotating shaft as described above. Figure 3 As shown, the turbine guide vanes are located in the shaded area. The outer surfaces of the multiple turbine guide vanes are fixed to the annular inner wall of the casing via an outer mounting bracket 4, while the inner surfaces of the multiple turbine guide vanes are fixed to the annular mounting surface of the inner ring via an inner mounting bracket 8. Furthermore, the multiple turbine guide vanes are arranged circumferentially along the annular mating surface between the inner ring and the casing. Ultimately, the pressure surfaces 121 and suction surfaces 122 of all turbine guide vanes together enclose a series of continuous annular flow channels (the pressure surfaces 121 and suction surfaces 122 of adjacent turbine guide vanes form a single flow channel), ensuring that the gas, after exiting the combustion chamber, can evenly enter the next stage of the moving blade assembly through these annular flow channels.

[0078] According to the above-described configuration, a gas turbine can accelerate the swirling flow of the gas using the turbine guide vanes. The blade airfoil 1, outer mounting frame 4, and inner mounting frame 8 remain constructed of metal, preserving the installation performance and reliability of traditional metal blades. Furthermore, by trimming the leading edge 11 of the metal blade airfoil 1, a CMC heat shield 2 is added to enhance the high-temperature resistance of the windward surface of the turbine guide vanes, where the turbine guide vanes first contact the gas. Due to the high-temperature resistance of the CMC material, the heat shield 2 is provided with a cooling air cavity 23 and heat dissipation holes 22. This allows the leading edge 11 area to withstand 1500°C high-temperature gas without the need for spray cooling, thereby reducing the amount of cooling air required. Furthermore, the coupled structure of the blade airfoil 1 and heat shield 2 forms a heat dissipation channel. Through the multiple heat dissipation holes 22 provided in the heat shield 2, cooling air can flow along the heat dissipation channel and provide efficient air film protection for the turbine guide vanes, enhancing the structural stability of the turbine guide vanes during operation and thereby improving the thermal energy conversion efficiency of the gas turbine.

[0079] The above describes embodiments of the present disclosure. However, these embodiments are merely for illustrative purposes, and are not intended to limit the scope of the present disclosure. Although each embodiment is described above separately, this does not mean that the measures in each embodiment cannot be used advantageously in combination. The scope of the present disclosure is defined by the appended claims and their equivalents. Those skilled in the art can make various substitutions and modifications without departing from the scope of the present disclosure, and these substitutions and modifications should all fall within the scope of the present disclosure.

Claims

1. A turbine guide blade, characterized in that: include: A blade body (1) comprises a leading edge (11) facing the incoming gas flow, a trailing edge (13) opposite to the leading edge (11), and a curved body portion (12) located between the leading edge (11) and the trailing edge (13); as well as A heat shield (2) is coated on the leading edge (11) and serves as a windward surface that first contacts the gas. A cold air cavity (23) is provided in the heat shield (2) and passes through the heat shield (2) in a longitudinal direction perpendicular to the flow direction of the gas. A plurality of heat dissipation channels are formed between the cold air cavity (23) and the pressure surface (121) and the suction surface (122) of the main body (12) to cool the heat shield (2).

2. The turbine guide vane according to claim 1, characterized in that The leading edge (11) comprises: an arc-shaped raised portion (111) extending in the longitudinal direction; a plurality of ribs (113) extending perpendicular to the longitudinal direction and spaced apart; and Two transition portions (114) are respectively located on both sides of the raised portion (111) and between the pressure surface (121) and the suction surface (122); The inner cross-section of the heat shield (2) has a substantially U-shape and comprises two side walls (21) covering the raised portion (111), and a bottom wall connected between the side walls (21), wherein the bottom wall is provided with a plurality of heat dissipation holes (22) respectively communicating with the cold air cavity (23) and the space between two adjacent ribs (113). The heat dissipation hole (22) and the space defined by the convex rib (113), the transition portion (114) and the end of the heat shield (2) form the heat dissipation channel.

3. The turbine guide vane according to claim 2, characterized in that The distal end of the protrusion (111) forms a flat portion (112) extending in the longitudinal direction, and a plurality of ribs (113) form both sides of the flat portion (112), so that the gas flowing out of the heat dissipation hole (22) is mixed in the space between the flat portion (112) and the bottom wall of the heat shield (2).

4. The turbine guide vane according to any one of claims 1 to 3, characterized in that The cross-section of the cold air cavity (23) perpendicular to the longitudinal direction is arc-shaped and has two arc segments whose concave directions are matched with the overall concave direction of the heat shield (2). The curvature of the arc segments also matches the curvature of the inner side wall (21) of the heat shield (2) and the curvature of the convex rib (113).

5. The turbine guide vane according to claim 2, characterized in that The main body (12) is provided with a first blind hole (123), and the first blind hole (123) extends from the outer side surface of the main body (12) in the longitudinal direction; A plurality of first exhaust holes (124) are formed on the main body (12) near the leading edge (11), extending from the first blind holes (123) to the pressure surface (121) and the suction surface (122); cold air flowing into the first blind holes (123) is discharged from the pressure surface (121) and the suction surface (122) through the first exhaust holes (124).

6. The turbine guide vane according to claim 5, characterized in that Also includes: A front air guide (3) is inserted into the first blind hole (123), and a plurality of first through holes (31) are provided on the side wall (21) of the front air guide (3) to guide the received cold air into the first blind hole (123); An external mounting frame (4) mounted on the outer side of the main body (12); a first cover plate (5) adapted to mount one end of the front air guide tube (3) extending out of the outer mounting frame (4) on the outer mounting frame (4), and covering the first blind hole (123) and the gap between the heat shield (2) and the leading edge (11) located on the outside, the cold air cavity (23) passing through the first cover plate (5) to communicate with the outside; and The second cover plate (6) is adapted to cover the gap between the heat shield (2) and the leading edge (11) located on the inner side.

7. The turbine guide vane according to claim 2, characterized in that The main body (12) is further provided with a second blind hole (125) located between the first blind hole (123) and the trailing edge (13), and the second blind hole (125) extends from the inner side surface of the main body (12) along the longitudinal direction; A plurality of second air exhaust holes (126) extending from the second blind holes (125) to the pressure surface (121) and the suction surface (122) are formed on the main body (12) near the trailing edge (13), and a portion of the cold air flowing into the second blind holes (125) is discharged from the pressure surface (121) and the suction surface (122) through the second air exhaust holes (126).

8. The turbine guide vane according to claim 7, characterized in that The trailing edge (13) is formed with a third exhaust hole (131) extending from the second blind hole (125) to the end of the trailing edge (13), and another portion of the cold air flowing into the second blind hole (125) is discharged from the end of the trailing edge (13) through the third exhaust hole (131).

9. The turbine guide vane according to claim 8, characterized in that Also includes: A rear air guide tube (7) is inserted into the second blind hole (125), and a plurality of second through holes (71) are provided on the side wall (21) of the rear air guide tube (7) to guide the received cold air into the second blind hole (125); an inner mounting frame (8) mounted on the inner side of the main body (12); and The third cover plate (9) is suitable for mounting one end of the rear air guide tube (7) extending out of the inner mounting frame (8) on the inner mounting frame (8) and covering the second blind hole (125).

10. A gas turbine, characterized in that: The invention comprises a turbine guide vane according to any one of claims 1 to 9.

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