阅读说明：本技术 一种采用端壁分区造型设计的涡轮叶栅 (Turbine blade cascade designed by adopting end wall partition modeling ) 是由 周逊 薛兴旭 杜鑫 王松涛 于 2020-12-17 设计创作，主要内容包括：本申请提供了一种采用端壁分区造型设计的涡轮叶栅,包括：端壁及多个叶片。端壁与叶片压力面之间设有压力侧凸起；压力侧凸起的各个轴向截面顶点均位于压力侧顶点线上。端壁与叶片吸力面之间设有吸力侧凸起,吸力侧凸起的各个轴向截面顶点均位于吸力侧顶点线上。本申请提供的涡轮叶栅,根据二次流发展机理以及吸力侧与压力侧的不同流场特征,对叶栅流道端壁进行针对性分区域造型处理设置压力侧凸起及吸力侧凸起,压力侧凸改变了压力面角区展向静压梯度分布,有效地降低了马蹄涡强度；吸力侧凸起增强吸力面角区的流场稳定性,且能够提高叶片尾缘吸力面角区展向静压梯度、抑制壁角涡与低能流体堆积,有效地减少了二次流损失。(The application provides an adopt turbine blade cascade of end wall subregion molding design, includes: an endwall and a plurality of vanes. A pressure side bulge is arranged between the end wall and the pressure surface of the blade; each axial section vertex of the pressure side protrusion is located on the pressure side vertex line. And a suction side bulge is arranged between the end wall and the suction surface of the blade, and the vertex of each axial section of the suction side bulge is positioned on the vertex line of the suction side. According to the turbine blade cascade, the pressure side bulges and the suction side bulges are arranged by performing targeted regional modeling treatment on the end wall of a flow channel of the blade cascade according to a secondary flow development mechanism and different flow field characteristics of a suction side and a pressure side, the pressure side bulges change the spanwise static pressure gradient distribution of an angle area of a pressure surface, and the horseshoe vortex strength is effectively reduced; the suction side bulge enhances the flow field stability of the suction surface angle area, can improve the spanwise static pressure gradient of the suction surface angle area at the trailing edge of the blade, inhibits wall angle vortex and low-energy fluid accumulation, and effectively reduces the secondary flow loss.)

1. A turbine cascade designed using endwall zoning, comprising: the air duct comprises an end wall and a plurality of blades arranged along the circumferential direction of the end wall, an air duct is formed between every two adjacent blades, and the air duct comprises an air inlet and an air outlet;

wherein a pressure side bulge is arranged between the end wall and the pressure surface of the blade; the pressure side peak of the pressure side bulge is positioned on the pressure surface; the intersection line of the pressure side bulge and the blade is a pressure side vertex line, and on each section of the pressure side bulge with the axis of the end wall as a normal line, each section vertex of the pressure side bulge is positioned on the pressure side vertex line; the projection length of a connecting line of the pressure side vertex and the leading edge point of the blade on an axial chord line of the blade is 5-20% of the length of the axial chord line; in a radial direction of the end wall, a sectional area of the pressure side protrusion gradually decreases from a bottom end of the pressure side protrusion to the pressure side apex.

2. The turbine blade cascade of claim 1,

the slope of the first inclined plane of the pressure side bulge adjacent to the air inlet is larger than the slope of the second inclined plane of the pressure side bulge adjacent to the air outlet.

3. The turbine blade cascade of claim 2,

the gradient of the first inclined plane is 1: 1-5: 1.

4. The turbine blade cascade of claim 2,

the gradient of the second inclined plane is less than 1: 5.

5. The turbine blade cascade of claim 2,

the first slash face is located between a frontal line of the turbine cascade and the pressure side apex.

6. The turbine blade cascade of any one of claims 1 to 5,

a suction side bulge is arranged between the end wall and the suction surface of the blade; the suction side apex of the suction side projection is located on the suction side of the blade; the intersection line of the suction side bulge and the blade is a suction side vertex line, and on each section of the suction side bulge with the axis of the end wall as a normal line, each section vertex of the suction side bulge is positioned on the suction side vertex line; the projection length of a connecting line of the suction side vertex and the leading edge point of the blade on an axial chord line of the blade is 80% -95% of the length of the axial chord line, and in the radial direction of the end wall, the sectional area of the suction side bulge is gradually reduced from the bottom end of the suction side bulge to the suction side vertex.

7. The turbine blade cascade of claim 6,

the gradient of the third inclined plane of the suction side bulge adjacent to the air inlet is smaller than the gradient of the fourth inclined plane of the suction side bulge adjacent to the air outlet.

8. The turbine blade cascade of claim 7,

the gradient of the third inclined surface is less than 1: 5.

9. The turbine blade cascade of claim 7,

the gradient of the fourth inclined plane is 1: 5-1: 1.

10. The turbine blade cascade of claim 7,

the length of the third inclined surface in the axial direction of the end wall is 15% -30% of the length of the axial chord line.

Technical Field

The application relates to the technical field of machinery, in particular to a turbine blade cascade designed by adopting an end wall partition modeling.

Background

The turbine is a rotary power machine for converting the energy of flowing working media into mechanical work, the fluid flowing speed of the turbine in the boundary layers of the end walls of the blade top and root areas close to the turbine is low in the rotating process of the turbine, the centrifugal force action of the airflow from the suction surface to the pressure surface is not enough to counteract the transverse pressure gradient between the pressure surface and the suction surface, and then secondary flow of the airflow from the pressure surface to the suction surface is formed in the boundary layers at the two positions. To achieve an improvement in turbine performance, it is necessary to reduce the generation of the secondary flow and to reduce the energy lost by the generation of the secondary flow.

Disclosure of Invention

The purpose of the present application is to provide a turbine blade cascade that can suppress the generation of a horseshoe vortex and can reduce secondary flow loss associated with the horseshoe vortex.

To achieve at least one of the above objects, the present application provides a turbine blade row designed with endwall partition molding, comprising: the air duct comprises an end wall and a plurality of blades arranged along the circumferential direction of the end wall, an air duct is formed between every two adjacent blades, and the air duct comprises an air inlet and an air outlet; wherein a pressure side bulge is arranged between the end wall and the pressure surface of the blade; the pressure side peak of the pressure side bulge is positioned on the pressure surface; the intersection line of the pressure side bulge and the blade is a pressure side vertex line, and on each section of the pressure side bulge with the axis of the end wall as a normal line, each section vertex of the pressure side bulge is positioned on the pressure side vertex line; the projection length of a connecting line of the pressure side vertex and the leading edge point of the blade on an axial chord line of the blade is 5-20% of the length of the axial chord line; in a radial direction of the end wall, a sectional area of the pressure side protrusion gradually decreases from a bottom end of the pressure side protrusion to the pressure side apex.

In some embodiments, the slope of the first inclined plane of the pressure-side protrusion adjacent to the air inlet is greater than the slope of the inclined plane of the pressure-side protrusion adjacent to the air outlet.

In some of the embodiments, the slope of the first inclined surface is 1: 1-5: 1.

In some of these embodiments, the slope of the second ramp is less than 1: 5.

In some of these embodiments, the first slash face is located between a frontal line and the pressure side apex of the turbine cascade.

In some of these embodiments, a suction side projection is provided between the endwall and the suction side of the blade; a suction side apex of the suction side projection is located on the suction surface; the intersection line of the suction side bulge and the blade is a suction side vertex line, and on each section of the suction side bulge with the axis of the end wall as a normal line, each section vertex of the suction side bulge is positioned on the suction side vertex line; the projection length of a connecting line of the suction side vertex and the leading edge point of the blade on an axial chord line of the blade is 80% -95% of the length of the axial chord line, and in the radial direction of the end wall, the sectional area of the suction side bulge is gradually reduced from the bottom end of the suction side bulge to the suction side vertex.

In some embodiments, a slope of a third inclined plane of the suction side protrusion adjacent to the air inlet is smaller than a slope of a fourth inclined plane of the suction side protrusion adjacent to the air outlet.

In some of these embodiments, the slope of the third ramp is less than 1: 5.

In some embodiments, the slope of the fourth slope is 1:5 to 1:1

In some of these embodiments, the length of the third chamfer in the axial direction of the end wall is 15% to 30% of the axial chord length.

The above technical scheme of this application has following advantage: the pressure side bulge improves the spanwise static pressure gradient of the pressure surface corner area near the front edge of the blade, so that the spanwise static pressure gradient distribution of the pressure surface corner area is changed, the downward washing motion of a main flow outside a boundary layer is inhibited, the effect of weakening the horseshoe vortex is further achieved, namely, the intensity of the horseshoe vortex in a secondary flow is reduced, the mechanical energy lost due to the horseshoe vortex is effectively reduced, and the working efficiency of the whole turbine blade cascade is effectively improved.

Drawings

The foregoing and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, which are provided for purposes of illustration only and are not necessarily drawn to scale or quantity with respect to the actual product. Wherein:

FIG. 1a is a schematic structural view of a turbine stator as described herein;

FIG. 1b is a schematic structural view of a turbine rotor according to the present application;

FIG. 2 is a partial schematic structural view of a first embodiment of the plurality of vanes shown in FIG. 1 b;

FIG. 3 is a schematic illustration of a partial structure of the turbine blade row illustrated in FIG. 2;

FIG. 4 is a partial schematic structural view of a second embodiment of the plurality of vanes shown in FIG. 1 b;

FIG. 5 is a schematic illustration of a partial structure of the turbine blade row illustrated in FIG. 4.

Wherein, the correspondence between the reference numbers and the part names of fig. 1a to 5 is:

the turbine blade assembly comprises an end wall 10, a stator casing inner ring 21, a stator casing outer ring 22, a rotor hub 23, blades 30, a pressure surface 31, a suction surface 32, an air duct 40, a pressure side protrusion 50, a first inclined surface 51, a second inclined surface 52, a suction side protrusion 60, a third inclined surface 61, a fourth inclined surface 62, a pressure side vertex line 70, a suction side vertex line 80 and a turbine blade cascade 100.

Wherein the arrows in the figure indicate the direction of flow of the fluid.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The following discussion provides a number of embodiments of the application. While each embodiment represents a single combination of applications, the various embodiments of the disclosure may be substituted or combined in any combination, and thus, the disclosure is intended to include all possible combinations of the same and/or different embodiments of what is described. Thus, if one embodiment comprises A, B, C and another embodiment comprises a combination of B and D, then this application should also be considered to comprise an embodiment that comprises A, B, C, D in all other possible combinations, although this embodiment may not be explicitly recited in the text below.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application, however, the present application may be practiced in other ways than those described herein, and therefore the scope of the present application is not limited by the specific embodiments disclosed below.

As shown in fig. 1a and 1b, the turbine blade row has two structures, one is a turbine stator blade row (as shown in fig. 1 a), one is a turbine rotor blade row (as shown in fig. 1 b), and the end wall 10 is a wall surface connected with the blades 30. As shown in fig. 1a, the turbine stator includes a plurality of blades 30, a stator casing inner ring 21, and a stator casing outer ring 22, the plurality of blades 30 are disposed between the stator casing inner ring 21 and the stator casing outer ring 22, an end wall 10 refers to a surface where the stator casing inner ring 21 and the stator casing outer ring 22 are connected to the blades 30, and the turbine stator includes two end walls 10. As shown in fig. 1b, the turbine rotor comprises a plurality of blades 30 and a rotor hub 23, the plurality of blades 30 is arranged on the rotor hub 23, the end wall 10 refers to the face of the rotor hub 23 to which the blades 30 are connected, and the turbine rotor comprises one end wall 10.

As shown in fig. 1a to 2, the present application provides a turbine blade row with an endwall partition molding design, comprising: an end wall 10 (i.e., a stator case inner ring 21, a stator case outer ring 22, or a rotor hub 23) and blades 30.

The plurality of blades 30 are arranged along the circumferential direction of the end wall 10, an air duct 40 is formed between adjacent blades 30, and the air duct 40 includes an air inlet and an air outlet.

A pressure side protrusion 50 is provided between the endwall 10 and the pressure surface 31 of the blade 30. The pressure side bosses 50 are cast integrally with the end walls.

The pressure side apex of the pressure side protrusion 50 is located on the pressure surface 31.

As shown in fig. 3, the intersection line of the pressure-side protrusion 50 and the vane 30 is a pressure-side apex line 70 (a thick line in the drawing), and each cross-sectional apex of the pressure-side protrusion 50 is located on the pressure-side apex line 70 in each cross section of the pressure-side protrusion 50 with the axis of the end wall 10 as a normal.

The projection length D1 of the line connecting the pressure side apex and the leading edge point of the blade 30 on the axial chord line of the blade 30 is 5% to 20% of the axial chord line length D0. The surface of the blade 30 along which the pressure of the spherical flow gradually increases is a pressure surface 31, and the surface of the blade 30 along which the pressure of the spherical flow gradually decreases is a suction surface 32. The leading edge of the vane 30 is the edge of the air intake side of the vane 30.

In the radial direction of the end wall 10, the sectional area of the pressure side protrusion 50 gradually decreases from the bottom end of the pressure side protrusion 50 to the pressure side apex. The pressure side protrusion 50 is a convex point like a cone.

The utility model provides a turbine blade cascade, protruding 50 of pressure side has improved near the near pressure surface 31 angular region span of blade 30 leading edge to static pressure gradient, thereby change the distribution of pressure surface 31 angular region span to static pressure gradient, restrain the "washdown" motion of the outer mainstream of boundary layer, and then play the effect that weakens the horseshoe vortex, can restrain the production of strong angle vortex, the intensity of horseshoe vortex in the secondary flow has been reduced promptly, the mechanical energy who loses because of the horseshoe vortex has been reduced effectively, the complete machine work efficiency of turbine blade cascade has been improved effectively.

As shown in fig. 3, in one embodiment of the present application, a slope of a first slope 51 of the pressure side protrusion 50 adjacent to the air inlet is greater than a slope of a second slope 52 of the pressure side protrusion 50 adjacent to the air outlet. In one embodiment of the present application, the slope of the first inclined surface 51 is 1:1 to 5: 1. The height of the first inclined surface 51 in the radial direction of the end wall 10 is H1, the length of the first inclined surface 51 in the axial direction of the end wall 10 is L1, and H1: L1 is 1: 1-5: 1. In one particular embodiment of the present application, the slope of the second ramp 52 is less than 1: 5. The height of the second inclined surface 52 in the radial direction of the end wall 10 is H2, the length of the second inclined surface 52 in the axial direction of the end wall 10 is L2, and H2: L2 is less than 1: 1-5: 1.

The first inclined plane 51 (windward side) has a higher gradient, further changes the spanwise static pressure gradient distribution of the pressure surface 31 angular region, further plays a role in weakening the horseshoe vortex, can further inhibit the generation of strong angular vortex, namely further reduces the intensity of the horseshoe vortex in secondary flow, effectively reduces the mechanical energy lost due to the horseshoe vortex, and effectively improves the overall working efficiency of the turbine blade cascade. The slope of the second inclined plane 52 is small, so that the wind passing through the second inclined plane 52 becomes gentle, wall angle vortex and low-energy fluid accumulation are inhibited, the mechanical energy lost due to the horseshoe vortex is effectively reduced, and the overall working efficiency of the turbine blade cascade is effectively improved.

As shown in fig. 2, in one embodiment of the present application, the first slash face 51 is located between the frontal line and the first vertex of the turbine cascade 100. The first inclined plane 51 is positioned in the air duct 40 and does not exceed the frontal line of the blade 30, so that the pressure side bulge 50 can fully change the static pressure gradient distribution in the spanwise direction of the angular region of the pressure surface 31, the action of the horseshoe vortex is weakened, the generation of strong angular vortex can be inhibited, the mechanical energy lost due to the horseshoe vortex is effectively reduced, and the overall working efficiency of the turbine blade cascade is effectively improved. The frontal line is a line connecting corresponding points of the leading edges of the blades 30 in the turbine cascade 100.

As shown in FIG. 4, in one embodiment of the present application, a suction side protrusion 60 is provided between the endwall 10 and the suction side 32 of the blade 30.

The suction side apex of the suction side projection 60 is located on the suction side 32 of the blade 30.

The line of intersection of suction side projection 60 with blade 30 is a suction side apex line 80, and the respective section apices of suction side projection 60 lie on suction side apex line 80 at respective sections of suction side projection 60 normal to the axis of endwall 10.

The projected length D2 of the line connecting the suction side apex and the leading edge point of the blade 30 on the axial chord line of the blade 30 is 80% -95% of the axial chord line length D0.

In the radial direction of the end wall 10, the cross-sectional area of the suction side projection 60 gradually decreases from the bottom end of the suction side projection 60 to the suction side apex. The suction side projection 60 is a conical-like convex point.

The windward side of the suction side protrusion 60 can construct a local contracted flow channel in the corner area of the suction surface 32 and improve the normal pressure gradient, so that the flow direction momentum of fluid in the corner area of the suction surface 32 can be improved, the flow field stability of the corner area of the suction surface 32 is enhanced, and the development of secondary flow is inhibited.

The leeward side of the suction side bulge 60 can construct a local expanding flow channel in the corner area of the suction side 32 and improve the static pressure of the root of the suction side 32 along the flow direction; therefore, the spanwise static pressure gradient of the 32-corner area of the trailing edge suction surface can be improved, wall angle vortex and low-energy fluid accumulation are inhibited, further, the mechanical energy lost due to secondary flow is effectively reduced, and the overall working efficiency of the turbine blade cascade is effectively improved.

As shown in FIG. 5, in one embodiment of the present application, the slope of the third sloped surface 61 of the suction side projection 60 adjacent to the intake vent is less than the slope of the fourth sloped surface 62 of the suction side projection 60 adjacent to the exhaust vent. The slope of the first slope 51 is greater than the slope of the fourth slope 62. In one particular embodiment of the present application, the slope of the third ramp 61 is less than 1: 5. The height of the third inclined surface 61 in the radial direction of the end wall 10 is H3, and the length of the third inclined surface 61 in the axial direction of the end wall 10 is L3, H3: L3 < 1: 5. In one embodiment of the present application, the slope of the fourth slope 62 is 1:5 to 1: 1. The height of the fourth inclined surface 62 in the radial direction of the end wall 10 is H4, the length of the fourth inclined surface 62 in the axial direction of the end wall 10 is L4, and H4: L4 is 1: 5-1: 1.

The smaller gradient of the third inclined surface 61 (windward side) can fully construct a local contracted flow channel in the angular region of the suction surface 32 and improve the normal pressure gradient, so that the flow direction momentum of fluid in the angular region of the suction surface 32 can be further improved, the flow field stability of the angular region of the suction surface 32 can be enhanced, and the development of secondary flow can be further inhibited.

The moderate slope of the fourth inclined surface 62 (leeward surface) can build a local expanding flow channel in the corner area of the effective suction surface 32 and improve the static pressure of the root of the suction surface 32 along the flow direction; therefore, the spanwise static pressure gradient of the 32-corner area of the trailing edge suction surface can be improved, wall angle vortex and low-energy fluid accumulation are inhibited, the mechanical energy lost due to the horseshoe vortex is effectively reduced, and the overall working efficiency of the turbine blade cascade is effectively improved.

In one embodiment of the present application, as illustrated in fig. 4 and 5, the length L3 of the third ramp 61 in the axial direction of the endwall 10 is 15% to 30% of the axial chord length D0.

The parameters of the third inclined surface 61 fully ensure that the third inclined surface 61 constructs a local contraction flow channel in the corner area of the suction surface 32 and improves the normal pressure gradient, so that the flow direction momentum of fluid in the corner area of the suction surface 32 can be further improved, the flow field stability of the corner area of the suction surface 32 is enhanced, and the development of secondary flow is further inhibited.

In one embodiment of the present application, the width of the connection between the pressure side protrusion and the end wall is 10% to 50% of the width of the air duct in the circumferential direction of the end wall. Similarly, in the circumferential direction of the end wall, the width of the joint of the suction side bulge and the end wall is 10% -50% of the width of the air duct.

According to the turbine blade cascade, the end wall of a flow channel of the turbine blade cascade is subjected to targeted regional modeling treatment according to a secondary flow development mechanism of the turbine blade cascade and different flow field characteristics of the suction side and the pressure side of the flow channel, pressure bulges are arranged on the pressure sides of a plurality of blades, and suction bulges are arranged on the suction sides of the blades. The pressure side bulge improves the static pressure gradient in the spanwise direction of the pressure surface angle area near the front edge of the blade, changes the static pressure gradient distribution in the spanwise direction of the pressure surface angle area and weakens the intensity of the horseshoe vortex. The windward side with the convex suction side can construct a local contraction flow channel in the angular region of the suction side, improve the normal pressure gradient, improve the flow direction momentum of fluid in the angular region of the suction side, enhance the flow field stability of the angular region of the suction side and inhibit the development of secondary flow. The leeward surface protruding from the suction side can construct a local expanding flow channel in a suction surface corner area and improve the static pressure of the root of the suction surface along the flow direction; thereby improving the static pressure gradient in the span direction of the trailing edge suction surface angle area and inhibiting wall angle vortex and low-energy fluid accumulation.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application. In this application, the term "plurality" means two or more unless explicitly defined otherwise. In this application, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The terms "mounted," "connected," "fixed," and the like are to be construed broadly, and for example, "connected" may be a fixed connection, a removable connection, or an integral connection; "coupled" may be direct or indirect through an intermediary. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In the description herein, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.