An endwall vane assembly with an angle adjustable film-cooling hole for a turbine

Abstract

The application discloses an end wall winglet assembly with an angle-adjustable film-cooling hole for a turbine; an end wall winglet platform is arranged on a wheel hub; a winglet blade is arranged on the upper surface of a chuck platform; blowing holes and blowing connecting pipes are arranged on the chuck platform; two mutually parallel flow-regulating cavity walls are arranged in a flow-regulating cavity in a flow-regulating cavity toothed disc; gear transmission toothed belts matched with linkage gears are arranged on the lower surface of the wheel hub; arc-shaped gear displacement limiting grooves are arranged on the lower surface of the wheel hub; a transmission gear in a transmission mechanism is engaged with the flow-regulating cavity toothed disc; the engagement of the linkage gears with the gear transmission toothed belts on the wheel hub is adjusted through the arc-shaped gear displacement limiting grooves, and the engagement of the driving gear with the flow-regulating cavity toothed disc can be adjusted. The application can reduce the interaction between the main flow and the cooling air, reduce the influence of the transverse secondary flow on the end wall cooling, improve the cooling efficiency of the end wall, make the temperature distribution of the end wall more uniform, and protect the blade end wall from ablation.

Description

Technical Field

[0001] This invention relates to the field of turbomachinery, specifically to an endwall winglet assembly with an adjustable mounting angle, coupled film cooling holes, and capable of suppressing secondary flow losses on the endwall and improving turbine aerodynamic performance. Background Technology

[0002] To improve aircraft cruising speed and reduce fuel consumption, the thrust-to-weight ratio requirements for aero-engine design are becoming increasingly stringent. To further enhance the thrust-to-weight ratio, aero-engines need to reduce their aerodynamic losses. Aero-engine turbine aerodynamic losses include blade profile losses and endwall losses, with secondary flow losses being the primary source of endwall losses. Endwall secondary flow is mainly due to the slower fluid velocity near the endwall, resulting in lateral flow of the fluid near the blade endwall under the influence of the pressure difference between the suction and pressure surfaces of the engine blades. This causes flow losses at the endwall. Endwall secondary flow losses can account for 30% to 50% of the total turbine blade losses. Therefore, methods for controlling endwall secondary flow losses in turbine blades have become a research hotspot to reduce turbine aerodynamic losses.

[0003] Currently, there are two main technologies for suppressing secondary flow losses at turbine endwalls: active control and passive control. Active control technologies mainly include boundary layer pumping and plasma excitation technologies; passive control technologies mainly include non-axisymmetric endwall technologies, endwall fusion technologies, and endwall winglet technologies. Among the passive control technologies, the endwall winglet technology is the endwall secondary flow control method with the most significant loss control effect.

[0004] Wing fence technology first appeared on swept wings of jet fighters in the 1940s. Because wing fences can block secondary flow from the wing root to the tip, reducing wingtip separation and improving the overall aerodynamic performance of swept wings, this technology gradually gained attention and widespread application. Later, researchers attempted to apply wing fence technology to the field of internal flow control in turbomachinery. Experimental studies were conducted on adding endwalls or suction surface wing fences to axial turbine blades. The results showed that wing fences could reduce flow losses in the blade cascade; however, due to limitations in the experimental conditions, the impact of the wing fence device on important secondary flow characteristics such as blade vorticity and outlet airflow angle distribution was not demonstrated.

[0005] In his paper "Numerical Simulation of Secondary Flow in Turbine Steerable Blade Cascade Controlled by Different Fence Heights," published in *Power Engineering* (Issue 4, 2008), Li Jun concluded that endwall fins can effectively suppress the loss of secondary flow within the blade cascade. This is reflected in two aspects: firstly, the endwall fins can reduce the ability of the horseshoe vortex pressure surface branch to merge into the suction surface corner region, thus reducing the channel vortex formed; secondly, the fins induce new vortex structures on their concave sides, reducing the lateral pressure gradient of the boundary layer in the near-end region, thereby suppressing the accumulation of low-energy fluids and reducing the intensity of the channel vortex.

[0006] In invention publication CN113323925A, an adjustable-height endwall wing fence for a compressor is disclosed. It includes: a compressor casing, a wing fence slide rail, a limiter, two sets of drive gears, two sets of variable-diameter slide rail gears, a wing fence assembly, and a power element. The variable-diameter slide rail gears are fitted onto the outer wall of the compressor casing and their axial movement within the casing is limited by the limiter. A variable-diameter groove is provided on the gear flange of the variable-diameter slide rail. A wing fence groove is provided on the wing fence slide rail, and wing fence blades are mounted on a wing fence support, with both ends of the wing fence support positioned within the variable-diameter groove. The power element has a drive gear that meshes with the variable-diameter slide rail gears. When the drive gear drives the variable-diameter slide rail gears to rotate, the variable-diameter grooves drive the wing fence blades to move radially along the compressor casing. This invention enables active adjustment of the endwall wing fence height, reducing losses caused by secondary flow in the compressor and providing a solution to the problem of increased losses due to varying incoming flow installation angles. However, this invention cannot achieve adjustable installation angle of the wing blade, and its adaptability to secondary flow control under variable compressor operating conditions is poor. Under variable operating conditions, the airflow angle of the compressor and turbine inflow will change significantly, requiring the design of endwall wing blades with variable installation angle.

[0007] In invention publication CN113006880A, a novel cooling device for turbine blade endwalls is disclosed, belonging to the field of cooling and thermal protection for turbine guide vane endwalls of aero-engines and ground-based gas turbines. The device includes a blade cascade passage, upper and lower endwalls, a slot, a baffle, small guide vanes, and a funnel-shaped groove. The blade cascade passage has an upper and lower endwall. The small guide vanes are evenly arranged in the blade cascade passage, with their front ends close to the downstream edge of the slot outlet. A baffle is located at the slot outlet, and the upstream end of the funnel-shaped groove is close to the slot outlet and directly opposite the leading edge of the blade.

[0008] In CN112282856A, an invention for suppressing channel vortices is disclosed, comprising a blade body and an endwall structure. The endwall structure consists of a pair of identical and symmetrically arranged vortex generators mounted at the leading edge root of the blade body. Compared to existing technologies, this invention, by arranging vortex generators at the leading edge root of the blade body, forms a pair of stable turbulent vortices opposite to the rotation direction of the channel vortex after the fluid passes through, thereby suppressing horseshoe vortices and fundamentally weakening the intensity of the channel vortex, reducing its aerodynamic losses. However, the vortex generators added in this invention are subject to high heat, and this structure cannot withstand the thermal corrosion generated in the high-temperature, high-pressure flow field of turbine blade operation.

[0009] In the invention disclosed in publication number CN216894545U, a tandem arrangement of blades for suppressing crossflow in the endwall boundary layer is described. The blades include a left blade and a right blade, with the left and right blades having the same structure. The right blade has several diffuser holes, a venting section on its left side, and a suppression section on its front side. This invention uses a tandem arrangement, symmetrically placing the left and right blades on opposite sides of the endwall. After the airflow is blocked by the blade cascade, the fluid can be depressurized through the gap between the left and right blades as it moves from bottom to top, preventing secondary flow due to excessive pressure difference. By providing multiple diffuser holes, venting sections, and suppression sections on the left and right blades, this invention effectively depressurizes and turbulent the secondary horseshoe vortex as it is about to form, thus preventing its formation. However, this design cannot withstand prolonged operation in the high-temperature, high-pressure turbine flow field.

[0010] In US2020362713A1, a turbomachinery is disclosed, including turbine endwall surface components; there are endwall fencings between turbine blades, and in the space between the turbine blades, each fencing has opposing concave and convex surfaces extending between a leading edge and a trailing edge, wherein the fencing has non-zero camber and constant thickness, is axially located near the leading edge of an adjacent turbine airfoil, and wherein at least one of the chord dimension and the span dimension of the fencing is smaller than the corresponding dimension of the turbine airfoil.

[0011] All the aforementioned studies have achieved control over endwall secondary flow and flow separation in the flow field through endwall geometry. However, the endwall geometry used in these studies / inventions only effectively suppresses turbine losses under limited turbine operating conditions. Under non-design conditions, the inlet airflow angle in the endwall region differs significantly from the design inlet airflow angle. Furthermore, the aforementioned studies / inventions do not adjust the endwall geometry for the flow field at the endwall under non-design conditions. Therefore, because the structure of the endwall secondary flow varies under different turbine operating conditions, a fixed endwall geometry cannot meet the requirements for controlling losses caused by the endwall secondary flow under complex operating conditions. In aero-engines, the turbine is located behind the combustion chamber, operating in a high-temperature, high-pressure environment. With increasing performance requirements for aero-engines, the operating temperature of the turbine also increases significantly. This leads to severe thermal corrosion problems on the turbine blades. Due to the special operating environment of turbine components, coupled with the interference of secondary flow near the endwall region, installing endwall geometry in the turbine will result in severe thermal corrosion of the endwall geometry by the high-temperature, high-pressure gas. Furthermore, due to their smaller geometric dimensions, the components are more susceptible to thermal corrosion and deformation. However, the aforementioned research / inventions do not address the heat loss protection of endwall geometries under the high temperature and pressure conditions of turbines. Therefore, new component designs are needed to address the multi-condition adaptability and long-life operation of turbine endwall geometries under high temperature and pressure conditions. Summary of the Invention

[0012] To control the losses caused by the complex and variable secondary flow on the endwall in the turbine channel, and to ensure that the control method can be effective for a long time in the high temperature and high pressure flow channel environment of the turbine, this invention proposes an endwall blade assembly with adjustable angle and film cooling holes for turbines.

[0013] This invention comprises two parts: an endwall wing blade platform and a transmission mechanism. The endwall wing blade platform is fitted into a mounting hole located on the circumference of the turbine hub. The chuck platform of the endwall wing blade platform is adapted to the mounting hole of the endwall wing blade platform on the turbine hub. Two gear rotation limiting plates are symmetrically distributed on both sides of the gear disk with flow regulating cavity, and the limiting blocks of the gear rotation limiting plates are respectively fitted into the annular groove of the gear disk on their respective sides;

[0014] The endwall wing blade platform includes wing blades, a chuck platform, air blowing pipes, a geared disc with a flow adjustment cavity, a chuck buckle, an air blowing connecting pipe, and an annular groove on the geared disc. Four air blowing holes are distributed on the chuck platform; each of the four air blowing holes is divided into a front group and a rear group. Four air blowing pipes are located on the lower surface of the chuck platform, also divided into front and rear groups, and each air blowing pipe is coaxial with its respective air blowing hole on the chuck platform. An annular chuck buckle is located at the outer edge of the upper surface of the chuck platform, through which the chuck platform is secured to the chuck platform mounting hole on the hub. An air blowing connecting pipe is located at the center of the lower surface of the geared disc with the flow adjustment cavity. The wing blade is vertically mounted on the upper surface of the chuck platform, with the leading edge of the wing blade located at the center of the two front air holes. The axis of the wing blade in top view is on the line connecting the center of the two front air holes and the center of the two rear air holes, and the plane of symmetry between the leading and trailing edges of the wing blade intersects the center of the chuck platform.

[0015] A gear drive belt is installed on the inner edge of the lower surface of the hub, and the gear drive belt engages with the linkage gears mounted on the hub. An arc-shaped gear displacement limiting groove is formed on the lower surface of the hub, engaging with the axle of the drive gear, and is positioned close to the outer edge of the gear disc with the flow regulating cavity; one end of the gear displacement limiting groove is close to the linkage gear, and the other end is close to the drive gear. The inner surfaces of the two ends of the gear displacement limiting groove are semi-circular.

[0016] The annular groove of the gear disk is located at the outer edge of the lower surface of the gear disk with the flow regulating cavity. The gear disk with the flow regulating cavity also has four symmetrically distributed air holes that communicate with the flow regulating cavity, which are divided into front gear disk air holes and rear gear disk air holes.

[0017] The transmission mechanism is installed on the lower surface of the hub and includes a linkage gear, a transmission gear, a drive gear, and a transmission gear adjusting link. The transmission gear meshes with the gear disc with the flow regulating cavity. Under the action of the transmission gear adjusting link, the linkage gear can mesh with the gear transmission belt on the hub. The drive gear can mesh with the gear disc with the flow regulating cavity.

[0018] The gear rotation limiting plate has an L-shaped longitudinal section, consisting of an arc-shaped vertical plate and a horizontal plate located at the lower end of the vertical plate, with the upper end of the vertical plate fixedly connected to the lower surface of the hub; the horizontal plate has an upwardly bent limiting block at the cantilever end.

[0019] The angle between the center of the semicircles at both ends of the gear displacement limiting groove and the center of the gear disk with the flow regulating cavity is θ, where θ = 30°.

[0020] Draw a line connecting the center of the gear disc with the flow regulating cavity to the center of the semicircle of the gear displacement limiting groove near the end of the linkage gear; draw a line connecting the center of the linkage gear to the center of the semicircle of the gear displacement limiting groove near the end of the linkage gear; the included angle between the two lines is β, where β = 120°.

[0021] The geared disc with flow control cavity has a closed rectangular flow control cavity inside. Within this cavity are two parallel rectangular flow control cavity walls; both walls are parallel to the long side of the flow control cavity, dividing it into three regions. In the two regions on either side, there is a front geared disc air inlet and a rear geared disc air inlet, respectively; the middle region is connected to an air blowing connection pipe.

[0022] The inner surface of the hub has an arc-shaped gear displacement limiting groove. The shaft of the transmission gear in the transmission mechanism is located within this gear displacement limiting groove and can move along it. A transmission gear adjusting rod is installed on the shaft of the transmission gear. The linkage gear and the driving gear in the transmission mechanism are located on opposite sides of the transmission gear. When the transmission gear is located at the upper end of the gear displacement limiting groove, it meshes with the linkage gear; when the transmission gear is located at the end of the gear displacement limiting groove, it meshes with the driving gear.

[0023] The diameter of the air blowing hole is 0.8 mm; the distance between the front group of air blowing holes and the center of the chuck platform is 4.09 mm; the center distance between the same group is 3.35 mm; the center distance between the front group of air blowing holes and the last two groups of air blowing holes is 5.36 mm; the angle between the air blowing hole and the end wall plane is 30°; and the axis of the air blowing hole is parallel to the axis of the end wall wing knife.

[0024] The transmission gear, linkage gear, and driving gear have the same structural parameters: number of teeth z = 15, module m = 2.75, and pressure angle α = 20°.

[0025] The distance between the geometric center of the flow regulating cavity and the center of the toothed disc with the flow regulating cavity is 11.25 mm; the horizontal distance between the wall of the flow regulating cavity and the center of the toothed disc with the flow regulating cavity is 3.5 mm.

[0026] This invention suppresses secondary flow losses at the turbine endwall by using endwall winglets to inhibit the lateral migration of secondary flow in the near-endwall region. The endwall winglets, with adjustable mounting angles, control secondary flow losses at the endwall and adapt to complex and variable secondary flow conditions. Furthermore, airflow through film cooling holes controls the surface temperature of the endwall winglets, minimizing thermal corrosion within the turbine flow path. This effectively controls secondary flow in the blade passages and ensures proper operation of the endwall winglets in the high-temperature turbine flow field by cooling the turbine flow path through the film cooling holes.

[0027] In this invention, the blade arrangement direction is defined as circumferential, the direction perpendicular to the blade arrangement direction is defined as spanwise, and the direction towards the axis is defined as spanwise downward. The position of the endwall winglets in the turbine can be adjusted according to the turbine blades, changing their position and angle in the flow channel. Furthermore, the number of endwall winglets and their positions can be increased and changed according to the specific turbine blade profile and the design requirements for control effects.

[0028] This invention represents a new advancement in controlling secondary flow losses at the turbine endwall by adding endwall fenders to regulate the lateral movement of low-energy fluid within the endwall. Therefore, the feasibility of this invention's technique for controlling secondary flow losses at the endwall through the endwall fenders themselves and the resulting incoming vortices has been proven.

[0029] This invention features an endwall wing with film cooling holes, which can suppress secondary flow losses on the turbine endwall and adjust the wing installation angle. Compared with the prior art, the beneficial effects of this invention are as follows: the low-energy fluid on the endwall migrates laterally under the pressure difference between the suction and suction surfaces, but is blocked by the endwall wing, thus suppressing the lateral migration of the secondary flow on the endwall. That is, the movement of the horseshoe vortex pressure surface branch in the turbine channel from the pressure surface to the suction surface causes the channel vortex to form later, thereby reducing losses. Figure 14a and Figure 14b The streamlines near the hub wall are shown for both the original blade cascade and the blade cascade with winglets installed. Comparing the streamlines of the two flow fields, it can be seen that, under the influence of the winglets, the secondary flow induced by the pressure difference between the suction and suction surfaces near the pressure surface (shown by the black dashed line in Figure 14) migrates backward, while the rear of the remaining blade passages only reaches the suction surface. Therefore, the secondary flow loss in the blade cascade passages is suppressed. Simultaneously, film cooling is employed to minimize the thermal corrosion effect during winglet operation, ensuring the structure can operate for extended periods under turbine conditions. Figure 15 The image shows the surface temperature distribution of the endwall winglets after film cooling. A higher grayscale value on the wall indicates a lower surface temperature of the endwall winglets. It can be seen that the cooling film holes significantly reduce the wall temperature of the endwall winglets, especially near the hub where the blade surface temperature is greatly controlled.

[0030] When using this invention, endwall winglets with adjustable angles are installed while suppressing secondary flow losses at the endwalls. Multiple endwall winglets are arranged in different ways on the hub surface, and the synchronous movement of the linked gears on the hub is ensured through gear transmission and a toothed belt, thereby achieving control of complex flow fields. For example... Figure 16 The arrangement shown.

[0031] This invention can reduce the interaction between the main flow and the cooling air, reduce the impact of the transverse secondary flow on the endwall cooling, improve the cooling efficiency of the endwall, make the endwall temperature distribution more uniform, and protect the blade endwall from ablation. Attached Figure Description

[0032] Figure 1 This is a top view of the endwall wing blade assembly with adjustable angle and film cooling holes and the turbine hub.

[0033] Figure 2 This is a bottom view of the endwall wing blade assembly with adjustable angle and film cooling holes and the turbine hub;

[0034] Figure 3 This is a schematic diagram of the endwall wing blade assembly with adjustable angle and air film cooling holes;

[0035] Figure 4 is a schematic diagram of the endwall wing platform structure. Figure 4a This is a 3D structural diagram of the endwall wing fence platform. Figure 4b This is an exploded 3D structural diagram of the endwall wing knife platform;

[0036] Figure 5 This is a front view of the endwall wing knife platform;

[0037] Figure 6 This is a top view of the endwall wing knife platform;

[0038] Figure 7 This is a bottom view of the endwall wing knife platform;

[0039] Figure 8 This is a left view of the endwall wing knife platform;

[0040] Figure 9 This is a cross-sectional view (AA) of the endwall wing platform;

[0041] Figure 10 This is a BB cross-sectional view of the endwall wing platform;

[0042] Figure 11 This is a CC cross-sectional view of the endwall wing knife platform;

[0043] Figure 12 These are the DD cross-sectional view of the endwall wing fence platform and the schematic diagram of the endwall wing fence platform and the wheel hub;

[0044] Figure 13 is a schematic diagram of the endwall wing knife platform and the gear set of the transmission mechanism. Figure 13a This is a schematic diagram of the planar structure of the endwall wing blade platform and the gear set of the transmission mechanism. Figure 13b A schematic diagram of the gear displacement limiting groove and a cross-sectional view of the fit between the transmission gear shaft and the gear displacement limiting groove. Figure 13c This is a schematic diagram of the meshing operation between the endwall wing knife platform and the linkage gear. Figure 13d This is a schematic diagram of the meshing operation between the endwall wing knife platform and the drive gear;

[0045] Figure 14a This is the original turbine wall limit streamline diagram. Figure 14bThis is the limiting streamline diagram of the inner wall of the endwall wing turbine;

[0046] Figure 15 This is a surface temperature cloud map of the wing blade after film cooling;

[0047] Figure 16 These are schematic diagrams of various endwall winglet arrangement schemes; among them, Figure 16 In this context, 'a' represents the arrangement of single-wing blades; Figure 16 In this context, 'b' represents the axial arrangement of the double-wing blades. Figure 16 In this context, 'c' represents the circumferential arrangement of the double-wing blades. Figure 16 In this context, 'd' represents the arrangement of four-winged blades in a row.

[0048] In the diagram: 1. Endwall wing platform; 2. Turbine blade; 3. Hub; 4. Linkage gear; 5. Transmission gear; 6. Drive gear; 7. Transmission gear adjusting linkage; 8. Gear rotation limit plate; 9. Gear transmission belt; 10. Wing blade; 11. Chuck platform; 12. Air blowing pipe; 13. Gear disk with flow adjustment chamber; 14. Chuck buckle; 15. Pressure probe measuring and control hole; 16. Air blowing hole; 17. Air blowing connecting pipe; 18. Gear disk annular groove; 19. Flow adjustment chamber wall; 20. Gear displacement limiting groove; 21. Gear disk air blowing hole Detailed Implementation

[0049] This embodiment is an endwall wing blade assembly with film cooling holes and an adjustable mounting angle. The endwall wing blade assembly includes an endwall wing blade platform 1 and a transmission mechanism. The transmission mechanism includes a linkage gear 4, a transmission gear 5, a drive gear 6, and a transmission gear adjusting linkage 7. The endwall wing blade platform 1 is fitted into a mounting hole located on the circumference of the turbine hub. The chuck platform 11 of the endwall wing blade platform 1 is flush with the upper surface of the turbine hub. The relative position of the endwall wing blade platform 1 is fixed by a trapezoidal opening in the hub and two gear rotation limiting plates 8 coaxial with the gear disks 13 with flow regulating chambers on the lower surface of the hub.

[0050] Two gear rotation limiting plates 8 are symmetrically distributed on both sides of the gear disk 13 with flow regulating cavity. The longitudinal section of each gear rotation limiting plate is L-shaped, consisting of an arc-shaped vertical plate and a horizontal plate located at the lower end of the vertical plate, with the upper end of the vertical plate fixedly connected to the lower surface of the hub 3. The cantilever end of the horizontal plate has an upwardly bent limiting block. Each limiting block is respectively embedded in the annular groove 18 of the gear disk on its respective side. The position of the vertical plate on the lower surface of the hub 3 must ensure that the distance between the inner surface of the arc-shaped vertical plate and the center of the gear disk with flow regulating cavity is greater than the radius of the gear disk with flow regulating cavity, thus maintaining a safe distance between them.

[0051] A gear drive belt 9 is installed on the inner edge of the lower surface of the hub, and the gear drive belt 9 engages with the linkage gear 4 installed on the hub. An arc-shaped gear displacement limiting groove 20 is formed on the lower surface of the hub, engaging with the axle of the drive gear 5, and is positioned close to the outer edge of the gear disc with the flow regulating cavity; one end of the gear displacement limiting groove is close to the linkage gear 4, and the other end is close to the drive gear 6. The inner surfaces of the two ends of the gear displacement limiting groove are semi-circular.

[0052] The endwall wing blade platform 1 includes a wing blade 10, a chuck platform 11, air blowing pipes 12, a geared disc with a flow adjustment cavity 13, a chuck latch 14, a pressure probe control hole 15, air blowing holes 16, an air blowing connecting pipe 17, and a gear disc annular groove 18. Four air blowing holes 16 are distributed on the chuck platform; each of the four air blowing holes is divided into a front group and a rear group. Four air blowing pipes 12 are located on the lower surface of the chuck platform, and these four air blowing pipes are also divided into a front group and a rear group, with each air blowing pipe coaxial with its respective air blowing hole 16 on the chuck platform. The pressure probe control hole is located at the leading edge of the wing blade.

[0053] The wing blade 10 is vertically mounted on the upper surface of the chuck platform 11, with its leading edge positioned at the center of the two front air holes 16. The axis of the wing blade 10, viewed from above, lies on the line connecting the centers of the two front air holes 16 and the centers of the two rear air holes, and the plane of symmetry between the leading and trailing edges of the wing blade intersects the center of the chuck platform. The chuck platform 11 is mounted on the upper surface of the gear disk 13 with a flow-adjusting cavity. An annular chuck buckle 14 is located at the outer edge of the upper surface of the chuck platform 11, through which the chuck platform is secured to the chuck platform mounting hole on the hub. An air-blowing connecting pipe 17 is located at the center of the lower surface of the gear disk 13 with a flow-adjusting cavity. The lower surface of the gear disk with a flow-adjusting cavity rests on a gear rotation limiting plate 8 on the hub 3, engaging with the annular groove 18 of the gear disk.

[0054] The gear disk 13 with a flow regulating cavity is a gear disk. The gear disk contains a flow regulating cavity. Four air holes 21, communicating with the flow regulating cavity, are symmetrically distributed on the gear disk 13. Each of the four air holes is divided into a front group and a rear group, with the two rear group air holes located in the middle of the upper disk and the two front group air holes located at the opening of the retaining ring. The flow regulating cavity within the gear disk with the flow regulating cavity is a closed rectangular chamber. Two parallel rectangular plates are distributed within this chamber; these rectangular plates are the two flow regulating cavity walls 19. Both flow regulating cavity walls are parallel to the long side of the flow regulating cavity, dividing it into three regions. In the two regions located on either side, there is one front group air hole and one rear group air hole, respectively. The middle region communicates with the air blowing connection pipe 17.

[0055] The hub 3 is existing technology. The transmission gear 5 is located on the lower surface of the turbine hub and meshes with the gear disc 13 with the flow regulating cavity; the linkage gear 4 and the drive gear 6 are located on both sides of the transmission gear, and the linkage gear 4 and the drive gear 6 mesh with the transmission gear respectively. One end of the transmission gear adjusting linkage 7 is mounted on the shaft of the transmission gear 5.

[0056] The transmission assembly includes a linkage gear 4, a transmission gear 5, a drive gear 6, a transmission gear adjusting rod 7, a gear rotation limiting plate 8, and a gear transmission belt 9. The transmission gear 5 is mounted on a gear displacement limiting groove 20 located on the turbine hub 3 via a gear shaft, and meshes with the flow regulating chamber gear plate. The gear shaft of the transmission gear 5 cooperates with the transmission gear adjusting rod 7 to control the position of the transmission gear 5 along the gear shaft direction. The linkage gear 4 and the drive gear 6 are adjusted to be located on opposite sides of the transmission gear. By adjusting the position of the gear shaft in the gear displacement limiting groove 20, the transmission gear 5 is made to mesh with either the linkage gear 3 or the drive gear 6.

[0057] The center of the gear disc 13 with the flow regulating cavity is on the same horizontal line as the center of the linkage gear 4. The center of the linkage gear 4 is on the same vertical plane as the center of the semicircle at the end of the gear displacement limiting groove near the linkage gear.

[0058] The angle between the center of the semicircles at both ends of the gear displacement limiting groove 20 and the center of the gear disk 13 with the flow regulating cavity is θ, where θ = 30°.

[0059] Draw a line connecting the center of the gear disc 13 with the flow regulating cavity and the center of the semicircle near the end of the gear displacement limiting groove of the linkage gear 4; draw a line connecting the center of the linkage gear 4 and the center of the semicircle near the end of the gear displacement limiting groove of the linkage gear; the included angle between the two lines is β, where β = 120°.

[0060] One end of the transmission gear adjusting link 7 is mounted on the gear shaft. The horizontal movement of the transmission gear adjusting link 7 drives the transmission gear 5. Pulling the transmission gear adjusting link 7 forward / backward changes the engagement relationship between the transmission gear 5 and the linkage gear 4 / drive gear 6. The gear shaft of the transmission gear 5 engages with the gear displacement limiting groove 20 and the transmission gear adjusting link 7 to control the position of the transmission gear 5. The gear displacement limiting groove 20 is an arc groove on the hub 3, its center being the same as the center of the adjustable endwall wing blade platform 1. Its function is to limit the movement path of the transmission gear 5 under the action of the transmission gear adjusting link 7 and ensure that the transmission gear 5 and the linkage gear 4 / drive gear 6 can engage at the end of the path. When the transmission gear 5 engages with the linkage gear 4, the linkage gear 4 engages with the gear transmission belt 9, and the gear transmission belt 9 meshes with the linkage gears 4 on the entire hub. Adjusting the gear transmission belt 9 will engage all the linkage gears 4, thereby changing the angle of the adjustable endwall wing blade platform 1 on the entire hub. When the transmission gear 5 engages with the linkage gear 6, such as... Figure 13d As shown, the drive gear 6 can be connected to a separate motor. By rotating the drive gear 6, the transmission gear 5 meshes with the drive gear 6 and the adjustable endwall wing knife platform 1 with the flow adjustment cavity gear disk 13, thereby achieving the purpose of adjusting the angle of a single adjustable endwall wing knife platform 1.

[0061] The turbine has an axial chord length of 140 mm, a blade spacing of 130 mm, and a blade height of 74 mm. In this embodiment, the parameters of the endwall wing fence are based on the above turbine parameters: the front end height of the wing fence is 9.2 mm, the rear end height is 22 mm, the thickness of the wing fence is 1.25 mm, and the length of the wing fence is 34.78 mm.

[0062] Regarding the relative positions of the air film cooling holes, endwall wing blades, and chuck platform, the diameter of the air blowing holes is 3mm, the distance from the front group of air blowing holes to the center of the chuck platform is 15.27mm, the spacing between each group of air blowing holes is 12.5mm, the spacing between the front and rear groups of air blowing holes is 20mm, the angle between the air blowing holes and the endwall plane is 30°, and the axis of the air blowing holes is parallel to the axis of the endwall wing blades.

[0063] Regarding the parameters of the endwall wing knife platform, the chuck platform has a diameter of 22.37 mm and a thickness of 1.25 mm. The chuck buckle has a diameter of 24 mm and a thickness of 1.25 mm. The distance between the chuck buckle and the geared disc with the flow adjustment cavity is 3.75 mm. The reinforcing rib with an arc shape between them has an angle of 300°, an inner diameter of 20.75 mm, and a thickness of 1.25 mm. The inner diameter and axis of the air blowing pipe are the same as those of the air blowing hole, and the pipe wall thickness is 1 mm. The geared disc with the flow adjustment cavity has a thickness of 5.75 mm, a diameter of 71 mm, 24 teeth, a module of 2.75, and a pressure angle of 20°. Below it is an annular groove of a ring gear disc with an inner diameter of 56.25 mm, a thickness of 1 mm, and a depth of 1.25 mm. An air blowing connecting pipe with a diameter of 2 mm and a thickness of 1 mm is located below the geared disc with the flow adjustment cavity.

[0064] The geared disk with flow control cavity contains a rectangular flow control cavity. Its main parameters are: its geometric center is 11.25 mm from the center of the geared disk; its major axis is parallel to the axis of the endwall blades; its lower surface is 2.5 mm from the lower surface of the geared disk; and its upper surface is 1.25 mm from the upper surface of the geared disk. The rectangle is 32.5 mm long and 20 mm wide. The flow control cavity has two walls, each 0.25 mm thick and 30 mm long, both horizontally 3.5 mm from the center of the geared disk. These walls connect to the end of the flow control cavity closest to the center of the geared disk, dividing the flow control cavity into three parts: left, middle, and right.

[0065] The relevant parameters of the transmission mechanism are as follows: the linkage gear, transmission gear, and driving gear are all gears of the same size, with a thickness of 5.75 mm, a diameter of 46.75 mm, a number of teeth of 15, a module of 2.75, and a pressure angle of 20°. The transmission gear adjusting rod has a width of 1.5 mm, an inner diameter of 2.125 mm, an outer diameter of 4.5 mm, and a thickness of 1.25 mm for the end ring. The gear displacement limiting groove has a groove width of 3.75 mm and a groove depth of 2.5 mm.

Claims

1. An endwall vane assembly with an angle adjustable film-cooled hole for a turbine, characterized by, The end wall wing platform and transmission mechanism are two parts; the end wall wing platform (1) is embedded in the installation hole on the circumference of the turbine hub; the chuck platform (11) of the end wall wing platform is matched with the end wall wing platform installation hole on the turbine hub; two gear rotation limiting pieces (8) are symmetrically distributed on both sides of the toothed disc (13) with flow regulating cavity, and the limiting blocks of the gear rotation limiting pieces are respectively embedded in the annular groove (18) of the gear disc on the side; The end wall wing platform includes wing blade (10), chuck platform, blowing pipe (12), toothed disc with flow regulating cavity, chuck buckle (14), blowing connecting pipe (17) and annular groove of gear disc; four blowing holes (16) are distributed on the chuck platform; the four blowing holes are divided into front group and rear group; there are four blowing pipes on the lower surface of the chuck platform, which are divided into front group and rear group, and each blowing pipe is coaxial with the blowing hole on the chuck platform; the annular chuck buckle is located at the outer edge of the upper surface of the chuck platform, and the chuck platform is clamped in the chuck platform installation hole on the hub through the chuck buckle; the blowing connecting pipe (17) is located at the center of the lower surface of the toothed disc with flow regulating cavity; the wing blade (10) is vertically installed on the upper surface of the chuck platform, and the leading edge of the wing blade is located at the center of the front group of two blowing holes, and the axis of the wing blade in plan view is on the line connecting the center of the front group of two blowing holes and the center of the rear group of two blowing holes; the symmetry plane between the leading edge and the trailing edge of the wing blade intersects with the center of the chuck platform; The gear transmission gear belt (9) is installed at the inner edge of the lower surface of the hub, and the gear transmission gear belt is matched with the linkage gear (4) installed on the hub; the arc-shaped gear displacement limiting groove (20) matched with the shaft of the transmission gear (5) is opened on the lower surface of the hub, and the gear displacement limiting groove is close to the outer edge of the toothed disc with flow regulating cavity; one end of the gear displacement limiting groove is close to the linkage gear, and the other end is close to the driving gear (6); the inner surfaces of the two ends of the gear displacement limiting groove are semicircular; The annular groove of the gear disc (18) is located at the outer edge of the lower surface of the toothed disc with flow regulating cavity (13); four toothed disc blowing holes (21) penetrating the flow regulating cavity are also symmetrically distributed on the toothed disc, which are divided into front group toothed disc blowing hole and rear group toothed disc blowing hole; There is an arc-shaped gear displacement limiting groove on the inner surface of the hub; the shaft of the transmission gear in the transmission mechanism is located in the gear displacement limiting groove and can move along the gear displacement limiting groove; the transmission gear adjusting connecting rod is installed on the shaft of the transmission gear; the linkage gear and the driving gear in the transmission mechanism are respectively located on both sides of the transmission gear; when the transmission gear is located at the upper end of the gear displacement limiting groove, the transmission gear is engaged with the linkage gear; when the transmission gear is located at the end of the gear displacement limiting groove, the transmission gear is engaged with the driving gear.

2. The endwall vane assembly with an angle adjustable film-cooling hole for a turbine of claim 1, wherein, The longitudinal section of the gear rotation limiting piece is L-shaped, which is composed of an arc-shaped vertical plate and a horizontal plate at the lower end of the vertical plate, and the upper end of the vertical plate is fixedly connected with the lower surface of the hub; the end of the cantilever end of the horizontal plate is provided with an upwardly-bent limiting block.

3. The endwall vane assembly with an angle adjustable film cooling hole of claim 1, wherein, The angle between the center of the semicircle at the two ends of the gear displacement limiting slot and the center of the tooth disc with flow regulating cavity is θ, and θ = 30°. The center of the tooth disc with flow regulating cavity and the center of the semicircle at the end of the gear displacement limiting slot close to the linkage gear are connected to form a first line, and the center of the linkage gear and the center of the semicircle at the end of the gear displacement limiting slot close to the linkage gear are connected to form a second line; the angle between the first line and the second line is β, and β = 120°.

4. The endwall vane assembly with an angle adjustable film cooling hole of claim 1, wherein The tooth disc with flow regulating cavity is internally provided with a closed rectangular flow regulating cavity; two rectangular flow regulating cavity walls parallel to each other are distributed in the flow regulating cavity; the two flow regulating cavity walls are parallel to the long side of the flow regulating cavity, and the flow regulating cavity is divided into three regions by the two flow regulating cavity walls; in the two regions on the two sides, there are respectively a front group of tooth disc air blowing holes and a rear group of tooth disc air blowing holes; the middle region is penetrated by the air blowing connecting pipe.

5. The endwall vane assembly with an angularly adjustable film-cooling hole of claim 1, wherein The diameter of the air blowing hole is 0.8 mm; the distance between the front group of air blowing holes and the center of the chuck platform is 4.09 mm; the center distance between the same group is 3.35 mm, the center distance between the front group of air blowing holes and the rear two groups of air blowing holes is 5.36 mm, the angle between the air blowing hole and the end wall plane is 30°, and the air blowing hole axis is parallel to the end wall airfoil axis.

6. The endwall vane assembly with an angle adjustable film cooling hole of claim 1, wherein The structural parameters of the transmission gear, linkage gear and driving gear are the same, the number of teeth z = 15, the modulus m = 2.75, and the pressure angle α = 20°.

7. The endwall vane assembly with an angle adjustable film cooling hole of claim 4, wherein The distance between the geometric center of the flow regulating cavity and the center of the tooth disc with flow regulating cavity is 11.25 mm; the horizontal distance between the flow regulating cavity wall and the center of the tooth disc with flow regulating cavity is 3.5 mm.

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